Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee Without IV Contrast Particularly when metal artifact reduction techniques are used, CT can be used to show the extent and width of lucent zones that may be less apparent on radiographs [20]. MRI and CT have both been shown to be more sensitive for detection of osteolysis than radiographs [116]. CT can be used to detect osteolysis and to determine the total volume of osteolytic lesions, particularly when metal reduction techniques are used [124]. CT is supported by Math et al [20] to look for osteolysis in patients with painful knee prostheses who have normal or equivocal radiographs and increased uptake on all 3 phases of a bone scan. Reish et al [67] found that only 17% of 48 lesions visible by CT were detected on radiographs. They suggested multidetector CT in cases in which osteolysis is expected, such as when there is aseptic loosening and gross polyethylene wear.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT allows the assessment of rotational positioning of the prosthesis components, which can affect patellofemoral tracking and varus/valgus ligamentous stability in flexion [125]. Imaging of rotational instability of a TKA is discussed in greater detail under Variant 5.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. There are varying reports on FDG sensitivity, specificity, and accuracy, which are likely in part related to nonuniform interpretation criteria and PET techniques. One overall estimate of FDG sensitivity, specificity, and accuracy in TKA is 96%, 77%, and 83%, respectively [126]. Although FDG is reportedly limited in evaluating patients with chronic knee pain after TKA [66,127], further advancements in FDG-PET may potentially be a promising tool in identifying prosthetic osteolysis [126]. Its exact role in the failed joint prosthesis; however, has yet to be determined. There is insufficient evidence to support routine use of FDG-PET/CT for assessment of instability.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoride PET/CT Whole Body Koob et al [128] noted a sensitivity of 95.00%, a specificity of 87.04% and an accuracy of 89.19% for the diagnosis of periprosthetic loosening of total hip and knee prosthesis with fluoride PET/CT. There is insufficient evidence to support routine use of fluoride PET/CT for assessment of instability.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoroscopy Knee There is no recent evidence supporting the routine use of fluoroscopy for the assessment of aseptic loosening, osteolysis, or instability. Fluoroscopy may be useful to see lucent lines in profile that could be obscured on standard AP radiographs [20,129,130] and can also be useful for demonstrating loosening under real-time manipulation. It can be useful in optimally positioning the joint for detection of radiographic osteolysis [129,130] and facilitates dynamic assessment of the knee under stress. In older studies, this procedure was determined to be useful, but it has been supplanted by other modalities and is now infrequently performed.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI Knee Without and With IV Contrast MRI without and with IV contrast is not useful for assessment of osteolysis or instability. The use of IV contrast for assessing loosening has not been described.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Imaging After Total Knee Arthroplasty MRI Knee Without IV Contrast The literature regarding MRI in the detection of implant loosening is evolving, and the available evidence supports its use. Using metal artifact reduction techniques, Fritz et al [93] described what they posited are distinct appearances for an intact periprosthetic interface (direct contact of the implant or cement with the surrounding bone), a periprosthetic fibrous membrane that indicates limited implant fixation that may or may not progress to loosening (1- to 2-mm thick layer with smooth margins surrounding the prosthesis along the bone interface) and frank bone resorption (a periprosthetic layer >2-mm thick with irregular margins). They reserve the use of the term loosening for cases in which MRI demonstrates circumferential osseous resorption together with signs of implant displacement, subsidence, or rotation. In a study of 116 knees in 114 patients that evaluated the interface type (normal, fibrous membrane, fluid, or osteolysis), percent integration (<33%, 33%-66%, or >66%), and presence of bone marrow edema. They determined MRI had higher sensitivity (84% versus 31%) but lower specificity (85% versus 96%) for patellar component loosening than did radiography [131].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI and CT have both been shown to be more sensitive for detection of osteolysis than radiographs [116]. MRI with metal artifact reduction techniques can detect osteolysis that is not visible on radiographs, even around the femoral component [96]. An MRI investigation of 11 TKA suspected of osteolysis on radiographs (and subsequently confirmed by surgery) found 10 cases with osteolysis at MRI and confirmed at surgery, 5 cases with additional osteolytic lesions detected on MRI, and 9 cases in which lesions were larger on MRI than on radiographs [97]. MRI can also show synovial changes due to particle disease before osteolytic lesions become apparent [22].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. When effective, metal suppression can be used, and MRI can allow direct visualization of ligaments and tendons about the knee [93].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. US Knee US has no significant role in assessing for aseptic prosthesis loosening and is not typically used for the assessment of osteolysis. US can be used to evaluate synovitis and soft tissues about the joint and to guide joint aspiration [132]. US is not typically used for assessment of instability but can be used to visualize and assess the medial and lateral collateral ligaments in the setting of TKA [133].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. WBC Scan and Sulfur Colloid Scan Knee In-111 WBC, Tc-99m labeled WBC, and Tc-99m sulfur colloid knee scans are not useful for evaluation of aseptic knee prosthetic loosening. WBC/marrow studies are used to differentiate prosthetic loosening from acute infection and can be performed without or with a corresponding bone scan, the latter without altering the WBC/marrow results [127]. A negative WBC scan negates an acute neutrophilic infection but may be falsely negative in chronic infection [101]. Love et al [109] reported WBC/marrow sensitivity, specificity, and accuracy as 96%, 87%, and 91%, respectively, for 150 total hip and knee replacements. Joseph et al [106] reported preoperative WBC/marrow imaging in 58 total hip and knee replacements with a sensitivity, specificity, and accuracy of 46%, 100%, and 88%, respectively. Palestro et al [107,134] described >90% accuracy and a specificity with a high sensitivity for WBC/marrow studies in the assessment of prosthetic joints. In the setting of chronic infection, differentiating chronic prosthetic infection from loosening can be more challenging, given that, in comparison with acute infections, chronic infections tend to have significantly fewer neutrophils, which are the predominant type of WBC labeled in an In-111 or Tc-99m-HMPAO WBC study, and radiolabeled WBCs are predominantly neutrophils. A decreased WBC sensitivity in osteomyelitis has also been attributed to a bacterial protective membrane or biofilm and to the effect of antibiotics [66]. Nonetheless, WBC/marrow scans to include SPECT/CT appear to be the imaging procedures of choice, with a high degree of accuracy for the failed joint prosthesis in the setting of a positive 3-phase bone scan because a negative WBC/marrow study does not include aseptic loosening [66]. In-111 WBC and Tc-99m sulfur colloid studies are not useful for assessment of instability.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Variant 4: Pain after total knee arthroplasty. Suspect periprosthetic or hardware fracture. Additional imaging following radiographs. Periprosthetic fractures may occur either during or after surgery and can involve the femur, tibia, or patella. Among periprosthetic fractures, supracondylar distal femur fractures are most common, whereas patellar fractures are rare [135,136]. Supracondylar fractures occur in 0.3% to 2.5% of TKA, usually within 2 to 4 years after surgery, and often occur in the setting of low-energy trauma [136]. Tibial fractures are associated with loose components and malalignment. Patellar fractures are associated with rheumatoid arthritis, steroid use, osteonecrosis, and malalignment. Most patients with periprosthetic fractures are elderly, having poor bone stock. Treatment depends


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Imaging After Total Knee Arthroplasty


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. on fracture classification, which often includes information regarding fracture location, degree of comminution, and position and stability of the prosthesis.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. 3-Phase Bone Scan Knee Radionuclide 3-phase bone scans can demonstrate increased activity at a site of periprosthetic fracture and can show fractures that are radiographically occult [137,138]. In older osteopenic individuals with low rates of bone remodeling, it may take 48 to 72 hours for the development of increased radionuclide activity at the site of fracture. Within 1 to 2 years after prosthesis surgery, the differential diagnosis for increased periprosthetic activity would include postoperative change; however, with serial imaging, this postoperative activity should decrease over time, whereas activity increasing over time would be suggestive of a prosthetic complication, such as a periprosthetic fracture, aseptic loosening, or infection. Therefore, no conclusion should be drawn on an isolated bone scan unless it yields a normal study.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Arthrography Knee There is no benefit to intraarticular contrast.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee With IV Contrast IV contrast is not helpful for CT assessment of periprosthetic fracture.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee Without and With IV Contrast IV contrast is not helpful for CT assessment of periprosthetic fracture.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee Without IV Contrast Radiographically occult fractures may be detected on CT when metal artifact reduction techniques are used [20].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. FDG-PET/CT Whole Body There is insufficient evidence to support the use of FDG-PET/CT for the assessment of periprosthetic fractures.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoride PET/CT Whole Body There is insufficient evidence to support the use of fluoride PET/CT for the assessment of periprosthetic fractures.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoroscopy Knee There is insufficient evidence to support the use of fluoroscopy for the assessment of periprosthetic fractures.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI Knee Without and With IV Contrast IV contrast is not helpful for CT or MRI assessment of periprosthetic fracture.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI Knee Without IV Contrast Radiographically occult fractures may be detected on MRI [22] when metal artifact reduction techniques are used.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. US Knee There is insufficient evidence to support the use of US for the assessment of periprosthetic fractures.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. WBC Scan and Sulfur Colloid Scan Knee There is insufficient evidence to support the use of In-111 WBC and Tc-99m sulfur colloid studies for the assessment of periprosthetic fractures.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Variant 5: Pain after total knee arthroplasty. Measuring component rotation. Additional imaging following radiographs. Malposition of femoral and tibial components may affect patellar alignment [139]. Excessive combined internal rotation of tibial and femoral components has been shown to be associated with patellar complications [139]. Moreover, Berger and Rubash [140] found that the amount of excessive combined internal rotation is directly proportional to the severity of patellofemoral complications. Abdelnasser et al [141] noted an internal rotation of the tibial component in TKA can lead to postoperative extension deficit.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. 3-Phase Bone Scan Knee There is insufficient evidence to support the use of bone scans for the assessment of rotational alignment of a TKA.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Arthrography Knee Intraarticular contrast is not helpful in the CT assessment of rotational alignment.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee With IV Contrast IV contrast is not helpful in the CT assessment of rotational alignment.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Imaging After Total Knee Arthroplasty


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee Without and With IV Contrast IV contrast is not helpful in the CT assessment of rotational alignment.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. FDG-PET/CT Whole Body Stumpe et al [79] found diffuse synovial and focal extrasynovial FDG uptake in patients with component malrotation; however, FDG-PET/CT studies are not routinely used for the assessment of rotational alignment of a TKA.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoride PET/CT Whole Body There is insufficient evidence to support the use of fluoride PET/CT for the assessment of rotational alignment of a TKA.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoroscopy Knee There is insufficient evidence to support the use of fluoroscopy for the assessment of rotational alignment of a TKA.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI Knee Without and With IV Contrast IV contrast is not useful for MRI assessment of rotational alignment.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI Knee Without IV Contrast When adequate metal reduction techniques are used, MRI can be used to assess TKA component rotation [146]. Anatomic landmarks and axes required for measurement of rotational alignment parameters can be identified [147,148]. In a study of 50 patients with painful TKA and 16 controls, Murakami et al [148] found high interobserver agreement in all the relevant rotational alignment measurements and found statistically significant relative internal rotation of the femoral component in patients with a painful TKA. MRI literature is evolving, and the available evidence suggests MRI may be useful in the assessment of component rotation with adequate metal reduction techniques.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. US Knee There is insufficient evidence to support the use of US for the assessment of rotational alignment of a TKA.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. WBC Scan and Sulfur Colloid Scan Knee There is insufficient evidence to support the use of In-111 WBC and Tc-99m sulfur colloid studies for the assessment of rotational alignment of a TKA.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Variant 6: Pain after total knee arthroplasty. Suspect periprosthetic soft-tissue abnormality unrelated to infection, including quadriceps or patellar tendinopathy (quadriceps or patellar tendon tears, postoperative arthrofibrosis, patellar clunk syndrome, or impingement of nerves or other soft tissues). Additional imaging following radiographs. The incidence of quadriceps or patellar tendon tears after TKA is low, at 0.17% to 2.5% [149]. Sharkey et al [12] reported that the incidence of postoperative arthrofibrosis is also relatively low, accounting for 4.5% of failures in this series and 6.9% of failures where noted in the Lombardi et al [111] series. Of note, patients with keloids have increased odds risk of arthrofibrosis following primary TKA [150]. Additional periprosthetic soft-tissue causes of postoperative knee pain are also uncommon and include impingement of nerves or other soft tissues.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. 3-Phase Bone Scan Knee There is insufficient evidence to support the use of 3-phase bone scan for the assessment of periprosthetic soft- tissue abnormalities.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Arthrography Knee CT is not useful for assessment of periprosthetic soft-tissue abnormalities. Intraarticular contrast is not significantly helpful in the CT assessment of quadriceps or patellar tendon tears, postoperative arthrofibrosis, patellar clunk syndrome, or impingement of nerves or other soft tissues.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee With IV Contrast CT is not useful for assessment of periprosthetic soft-tissue abnormalities. IV contrast is not significantly helpful in the CT assessment of quadriceps or patellar tendon tears, postoperative arthrofibrosis, patellar clunk syndrome, or impingement of nerves or other soft tissues.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee Without and With IV Contrast CT is not useful for assessment of periprosthetic soft-tissue abnormalities. IV contrast is not significantly helpful in the CT assessment of quadriceps or patellar tendon tears, postoperative arthrofibrosis, patellar clunk syndrome, or impingement of nerves or other soft tissues.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. CT Knee Without IV Contrast There is insufficient evidence to support the use of CT without IV contrast for the assessment of periprosthetic soft- tissue abnormalities.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. FDG-PET/CT Whole Body There is insufficient evidence to support the use of FDG-PET/CT for the assessment of periprosthetic soft-tissue abnormalities.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoride PET/CT Whole Body There is insufficient evidence to support the use of fluoride PET/CT for the assessment of periprosthetic soft-tissue abnormalities.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Fluoroscopy Knee There is insufficient evidence to support the use of fluoroscopy for the assessment of periprosthetic soft-tissue abnormalities.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. MRI Knee Without IV Contrast MRI that uses robust metal reduction techniques can be used for evaluation of quadriceps or patellar tendinopathy in patients with TKA [152] and for evaluation of arthrofibrosis [93]. MRI can also demonstrate suprapatellar arthrofibrosis that can be associated with post TKA patellar clunk syndrome [147]. The presence of MRI measurable abundant thick fibrotic tissue in patients with a clinical diagnosis of knee fibrosis is of benefit to knee surgeons faced with patients with stiff TKA and can facilitate the decision to debride the knee, restore range of motion, and revise the implant [153]. MRI is beneficial for the workup of periarticular soft-tissue masses, including neoplastic masses and inflammatory pseudotumors [154].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. US Knee US can be used for evaluation of quadriceps or patellar tendinopathy [155-157], postsurgical arthrofibrosis [158], and periarticular soft-tissue masses in patients with TKA. One review discusses the use of dynamic US to look for causes of snapping knee, including patellar clunk, snapping popliteus, and snapping related to component/liner malposition [159]. A case report discussed the utility of using dynamic US for the workup of patellar clunk syndrome [160].


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. WBC Scan and Sulfur Colloid Scan Knee There is insufficient evidence to support the use of In-111 WBC and Tc-99m sulfur colloid studies for the assessment of periprosthetic soft-tissue abnormalities.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Imaging After Total Knee Arthroplasty

Imaging After Total Knee Arthroplasty. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Head Trauma Child PCAs

Head Trauma Child PCAs. Introduction/Background Head trauma is a common indication for cranial imaging in children. Although traumatic brain injury is a leading cause of death and disability in children [1], the vast majority of head injuries are uncomplicated, transient, and do not require intervention [2]. The necessity of identifying clinically relevant, potentially treatable injury must be weighed against the risks of performing unwarranted imaging studies, possible unnecessary sedation, and inappropriate resource utilization.


Head Trauma Child PCAs

Head Trauma Child PCAs. The precise criteria for minor head injury are not consistent in the literature, but this usually refers to a patient with normal or near-normal postevent mental status and is often defined by a Glasgow Coma Scale (GCS) of 14 or 15 [3]. The probability of significant anatomic injury in minor head trauma is low. Approximately 3% to 5% of children with minor head trauma have identifiable abnormalities by imaging but typically less than 1% requires neurosurgical intervention [4-7].


Head Trauma Child PCAs

Head Trauma Child PCAs. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document.


Head Trauma Child PCAs

Head Trauma Child PCAs. Reprint requests to: publications@acr.org


Head Trauma Child PCAs

Head Trauma Child PCAs. Head Trauma-Child injury but resulted in a relatively high rate of CTs [13]. Additional smaller validation trials in the United States and abroad have also determined the PECARN criteria for very low risk criteria to be 100% sensitive [14-17].


Head Trauma Child PCAs

Head Trauma Child PCAs. Although precise comparison among the clinical decision rules is limited by differences in methodology and outcomes, the PECARN criteria remain the most widely validated, particularly for very young children, because of the high sensitivity and strong validation; the PECARN guidelines have been incorporated into the clinical variants for acute minor pediatric head trauma imaging. The PECARN criteria are summarized in Appendix 1.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI The identification of small bleeds, particularly in the posterior fossa or brainstem, is further increased with hemesensitive techniques such as susceptibility-weighted imaging [2,24-26]. Diffusion-weighted imaging can be helpful in identifying nonhemorrhagic injuries and associated ischemia as well [27]. Standard MRI sequences have a low sensitivity for skull fractures.


Head Trauma Child PCAs

Head Trauma Child PCAs. In recent years, limited rapid brain MRI techniques have been investigated as a means to evaluate pediatric head trauma without the need for sedation. Preliminary data suggest variations of this method may be helpful in following known intracranial hemorrhage documented by CT, but the sensitivity of rapid MRI in lieu of CT remains uncertain [28-31]. Additionally, there is no single uniform definition for rapid brain MRI techniques, and protocols vary among institutions. This is a rapidly evolving area of investigation but, at this time, there is no distinct procedural assignment for fast brain MRI in the ACR lexicon.


Head Trauma Child PCAs

Head Trauma Child PCAs. Ultrasound A few recent studies in children have suggested ultrasound (US) can detect calvarial fractures with a sensitivity close to that of CT [32]. However, even in infants with open fontanelles, in which US imaging of the brain is possible, US lacks sensitivity for small subdural hematomas, particularly in the posterior fossa, as well as other small extra-axial hemorrhages. Because intracranial injury can occur with or without fractures and US does not have a high sensitivity for hemorrhages, it does not currently have a significant role in head trauma imaging and as such is not considered in these variant procedures.


Head Trauma Child PCAs

Head Trauma Child PCAs. Discussion of Procedures by Variant Variant 1: Child. Minor acute blunt head trauma. Very low risk for clinically important brain injury per PECARN criteria. Excluding suspected abusive head trauma. Initial imaging. Radiography Skull Not all skull fractures are evident by radiographs, and up to 50% of intracranial injuries in children occur in the absence of fracture [2,33]. Therefore, radiographs are not sufficient to evaluate for traumatic injury [9].


Head Trauma Child PCAs

Head Trauma-Child

Head Trauma Child PCAs. Head Trauma-Child


Head Trauma Child PCAs

Head Trauma Child PCAs. CTA Head There is no relevant literature or expert consensus supporting the use of CT angiography (CTA) in the initial evaluation of children with minor trauma and very low risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Head There is no relevant literature or expert consensus supporting the use of MRI in the initial evaluation of children with minor trauma and very low risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRA Head There is no relevant literature or expert consensus supporting the use of MR angiography (MRA) in the initial evaluation of children with minor trauma and very low risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Arteriography Cerebral There is no relevant literature or expert consensus supporting the use of conventional cerebral angiography in the initial evaluation of children with minor trauma and very low risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Variant 2: Child. Minor acute blunt head trauma. Intermediate risk for clinically important brain injury per PECARN criteria. Excluding suspected abusive head trauma. Initial imaging. Radiography Skull Not all skull fractures are evident by radiographs, and up to 50% of intracranial injuries in children occur in the absence of fracture [2,33]. Therefore, radiographs are not sufficient to evaluate for traumatic injury [9].


Head Trauma Child PCAs

Head Trauma Child PCAs. CT may be considered in lieu of careful clinical observation in instances of parental preference, multiple risk factors, worsening clinical symptoms or signs during observation, and in young infants in which observational assessment is more challenging.


Head Trauma Child PCAs

Head Trauma-Child


Head Trauma Child PCAs

Head Trauma Child PCAs. CTA Head There is no relevant literature or expert consensus supporting the use of CTA in the initial evaluation of children with minor head injury and intermediate risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Head MRI is sensitive for acute intracranial hemorrhage and other intracranial traumatic injury. However, MRI in the acute setting is frequently impractical. The examination requires preimaging safety screening, is significantly longer than CT, and younger children often need sedation to compete the examination, further delaying time to imaging. IV contrast is typically of little use in evaluation of acute trauma.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRA Head There is no relevant literature or expert consensus supporting the use of MRA in the initial evaluation of children with minor head injury and intermediate risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Arteriography Cerebral There is no relevant literature or expert consensus supporting the use of conventional cerebral angiography in the initial evaluation of children with minor head injury and intermediate risk for intracranial injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Variant 3: Child. Minor acute blunt head trauma. High risk for clinically important brain injury per PECARN criteria. Excluding suspected abusive head trauma. Initial imaging. Radiography Skull Not all skull fractures are evident by radiographs, and up to 50% of intracranial injuries in children occur in the absence of fracture [2,33]. Therefore, radiographs are not sufficient to evaluate for traumatic injury [9].


Head Trauma Child PCAs

Head Trauma Child PCAs. High-risk factors for intracranial injury from minor head trauma in children <2 years of age by PECARN criteria include those with a GCS of 14, other signs of altered mental status, or signs of any palpable skull fracture. The risk of clinically significant intracranial injury in these patients is estimated at approximately 4.4% [5].


Head Trauma Child PCAs

Head Trauma Child PCAs. Although still relatively uncommon, the risk of interveneable injury is substantial enough that imaging is strongly recommended. CT has the advantage of rapid acquisition and excellent sensitivity for acute intracranial hemorrhage and fractures.


Head Trauma Child PCAs

Head Trauma Child PCAs. CTA Head Most vascular injuries in children are cervical, and there remains a relative paucity of evidence-based literature regarding the prevalence and nature of isolated intracranial vascular injury in pediatric head trauma. Intracranial vascular injuries have been reported in children with minor head trauma but are likely uncommon [19,34,35]. Vascular imaging is usually not a standard component of initial first-line imaging evaluation in patients with minor head trauma. However, if there are clinical symptoms or signs on other imaging raising suspicion for vascular injury, such as basilar fracture through a vascular canal, CTA may be considered for rapid assessment in the acute setting.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Head MRI is sensitive for acute intracranial hemorrhage and other intracranial traumatic injuries. However, MRI in the emergent setting is frequently impractical. The examination is typically significantly longer than CT, requires safety screening, results take longer to obtain, and younger children often need sedation to complete the examination, further delaying assessment. IV contrast is typically of little use in evaluation of acute trauma.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRA Head There remains a relative paucity of evidence-based literature regarding the prevalence and nature of vascular injury in minor pediatric head trauma. Vascular injuries have been reported in children with minor head trauma but are likely uncommon [19,34,35]. Vascular imaging is generally not a standard component of initial first-line imaging evaluation in patients with minor head trauma. If there are clinical or other imaging signs suggestive of vascular injury, MRA could be considered. MRA can be performed without IV contrast using time-of-flight sequences, although IV contrast may be helpful for clarification in some instances, particularly when imaging is limited by tortuosity or flow artifact.


Head Trauma Child PCAs

Head Trauma-Child

Head Trauma Child PCAs. Head Trauma-Child


Head Trauma Child PCAs

Head Trauma Child PCAs. Variant 4: Child. Moderate or severe acute blunt head trauma (GCS less than or equal to 13). Excluding suspected abusive head trauma. Initial imaging. Radiography Skull Not all skull fractures are evident by radiographs, and up to 50% of intracranial injuries in children occur in the absence of fracture [2,33]. Therefore, radiographs are not sufficient to evaluate for traumatic injury [9].


Head Trauma Child PCAs

Head Trauma Child PCAs. CT Head Moderate and severe head injury is typically associated with post-traumatic mental status changes. Despite the lower incidence and fewer numbers of studies addressing more significant injury in children, there is little debate regarding the need for imaging because of the greater incidence of intracranial injury in patients with decreased GCS [36]. CT has the advantage of rapid acquisition and excellent sensitivity for traumatic injuries, such as herniation or hemorrhage, which benefit from prompt intervention.


Head Trauma Child PCAs

Head Trauma Child PCAs. CTA Head Imaging for vascular injury is primarily guided by clinical suspicion or imaging findings, such as fracture through the skull base or vascular channels. Most literature regarding vascular injury in the pediatric population is confined to small series, and the true incidence and natural history of these injuries in children remains uncertain [19]. However, vascular imaging should be considered in patients with evidence of arterial stroke by examination or by imaging as well as those with fractures extending through the skull base or vascular channels, which are typically encountered in higher impact traumas [37,38]. CTA provides high spatial resolution and rapid assessment for vascular injuries.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Head Patients with more significant trauma and lower GCS are more likely to have sustained shear injury or ischemia, and MRI may have a higher yield for prognosis in this instance [25,39]. However, because of the time required to arrange and perform the examination and possible need for sedation, MRI can be difficult to accomplish emergently and should not delay evaluation. IV contrast is typically of little use in evaluation of acute trauma.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRA Head MRA can evaluate the intracranial vasculature and can be performed in conjunction with MRI when vascular injury is clinically suspected. However, as with standard MRI, this examination may be difficult to perform emergently. MRA can be performed without contrast using time-of-flight sequences, although IV contrast may be helpful for clarification in some instances, particularly when imaging is limited by tortuosity or flow artifact.


Head Trauma Child PCAs

Head Trauma Child PCAs. Arteriography Cerebral Conventional cerebral angiography remains the definitive diagnostic test for vascular injury and can demonstrate subtle abnormalities that may be occult on either CTA or MRA. However, because of the invasive procedure and need for sedation, conventional angiography should be reserved for problem solving in cases with uncertain noninvasive imaging and high clinical suspicion of vascular injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Variant 5: Child. Subacute blunt head trauma with cognitive or neurologic signs. The exact definition of subacute injury varies, but subacute head injury is typically defined as occurring between 8 days and 1 month after the initial traumatic event [40,41]. Injury may be caused by secondary processes, such as herniation from worsening parenchymal edema, ischemia, hydrocephalus, and progressive or delayed hemorrhage. During the subacute phase, up to 30% of contusions may cause worsening mass effect with edema from toxic metabolites released into the surrounding tissue and cerebral autoregulation dysfunction [42].


Head Trauma Child PCAs

Head Trauma Child PCAs. Radiography Skull There is no relevant literature or expert consensus regarding the use of skull radiographs in children with subacute head trauma and cognitive or neurologic signs.


Head Trauma Child PCAs

Head Trauma Child PCAs. CT Head Patients with a significant change in neurologic status are at a high risk for progressive intracranial injury, may require neurosurgical intervention, and may benefit from imaging [43]. CT can provide rapid, accurate assessment for progressive hemorrhage, herniation, and hydrocephalus. In one study of 116 children with CT positive for


Head Trauma Child PCAs

Head Trauma-Child


Head Trauma Child PCAs

Head Trauma Child PCAs. traumatic head injury, 9 patients experienced neurologic deterioration, 6 of whom required neurosurgery [44]. However, all patients undergoing intervention were identified clinically, without imaging, reflecting the importance of clinical examination in this population.


Head Trauma Child PCAs

Head Trauma Child PCAs. CTA Head Imaging for vascular injury is primarily guided by clinical suspicion. Most literature regarding vascular injury in the pediatric population is confined to small series, and the true incidence and natural history of these injuries in children remains uncertain [19]. However, vascular imaging should be considered in patients with evidence of arterial stroke by examination or by imaging as well as those with fractures extending through the skull base vascular channels [37]. CTA provides high spatial resolution and rapid assessment for vascular injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Head MRI may be helpful in evaluating persistent, unexplained, or new neurological deficits in the subacute setting. MRI has a high sensitivity for blood products, including small brainstem and infratentorial hemorrhages as well as subacute hemorrhage, which becomes less dense on CT over time. The superior detection of nonhemorrhagic contusions and ischemia may be particularly helpful in the absence of findings on prior CT [38]. However, a standard MRI requires the patient be stable enough to tolerate a lengthier examination.


Head Trauma Child PCAs

Head Trauma Child PCAs. In recent years, limited rapid MRI techniques have been investigated as a means to evaluate pediatric head trauma without the need for sedation. Preliminary data suggest variations of this method may be helpful in following known intracranial hemorrhage documented by CT, but the sensitivity of rapid MRI in lieu of CT remains uncertain [28-31].


Head Trauma Child PCAs

Head Trauma Child PCAs. Contrast-enhanced sequences are generally not indicated unless there is a concern for infection, such as from penetrating injury or fractures involving the sinuses.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRA Head MRA can evaluate the intracranial vasculature and can be performed in conjunction with MRI when vascular injury is clinically suspected. However, as with standard MRI, it may be difficult to perform emergently. MRA can be performed without IV contrast using time-of-flight sequences, although IV contrast may be helpful for clarification in some instances, particularly when imaging is limited by tortuosity or flow artifact.


Head Trauma Child PCAs

Head Trauma Child PCAs. Arteriography Cerebral Conventional cerebral angiography remains the definitive diagnostic test for vascular injury and can demonstrate subtle abnormalities that may be occult on either CTA or MRA. However, because of the invasive procedure and need for sedation, conventional angiography should be reserved for problem solving in cases with uncertain noninvasive imaging and high clinical suspicion of injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Variant 6: Child. Chronic blunt head trauma with new or progressive cognitive or neurologic deficits. Excluding suspected abusive head trauma and post-traumatic seizure. Postconcussion symptoms are common after head injury. In mild traumatic cases, imaging in the chronic setting is usually negative, and in cases in which more severe trauma or prior intracranial injury has occurred, imaging in the chronic period rarely reveals additional actionable changes [45-47].


Head Trauma Child PCAs

Head Trauma Child PCAs. CT Head There are little data regarding the use of CT in children in the chronic post-traumatic setting. A few studies addressing CT is this setting support a low diagnostic yield for imaging in the post-traumatic setting [46,47]. One study of 52 children with chronic head injury demonstrated CTs performed on only 8 patients [46]. One patient was found to have a fracture. No intracranial injury was detected. CT has limited sensitivity for nonacute intracranial hemorrhage and small contusions. CT likely has little role in evaluating most children with chronic head injury but may be a consideration when results are needed quickly.


Head Trauma Child PCAs

Head Trauma-Child

Head Trauma Child PCAs. Head Trauma-Child


Head Trauma Child PCAs

Head Trauma Child PCAs. CTA Head Although late post-traumatic vascular complications, such as pseudoaneurysm, can occur, there is no substantial literature or expert consensus supporting the use of CTA in children in chronic traumatic injury. Imaging for vascular injury is primarily guided by clinical suspicion or imaging findings, such as fracture through the skull base or vascular channels. In these instances, CTA provides high spatial resolution and rapid assessment for vascular injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRA Head Although late post-traumatic vascular complications, such as pseudoaneurysm, can occur, there is no substantial literature or expert consensus supporting the use of MRA in children in chronic traumatic injury. Imaging for vascular injury is primarily guided by clinical suspicion or imaging findings, such as fracture through the skull base or vascular channels. MRA can be performed without IV contrast using time-of-flight sequences, although contrast may be helpful for clarification in some instances, particularly when imaging is limited by tortuosity or flow artifact.


Head Trauma Child PCAs

Head Trauma Child PCAs. Arteriography Cerebral There is no relevant literature or expert consensus regarding the use of conventional cerebral angiography in evaluating children with chronic head trauma.


Head Trauma Child PCAs

Head Trauma Child PCAs. FDG-PET/CT Brain There is no relevant literature or expert consensus regarding the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT of the brain in evaluating children with chronic head trauma.


Head Trauma Child PCAs

Head Trauma Child PCAs. MR Spectroscopy Head There have been few studies investigating spectroscopic changes in the brain of children with prior head trauma. Some preliminary data suggest there may be reduced N-acetyl aspartate metabolites in the corpus callosum in these children [50]. However, these studies are limited by patient selection and very small sample size, and the clinical relevance of these findings in children is unclear.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Head without IV Contrast with DTI There have been a few studies suggesting that post-traumatic microstructural changes in the white matter can be identified with diffusion-tensor imaging (DTI). However, these studies are usually in older adolescents and young adults, and the data remain limited by small sample sizes in select populations. There are little data regarding the routine use of this technique in children.


Head Trauma Child PCAs

Head Trauma Child PCAs. MRI Functional (fMRI) Head without IV Contrast Some preliminary work suggests that changes in connectivity in pediatric patients may correlate with postconcussion symptoms [51,52]. However, studies are limited by small, select sample sizes, and there remains no strong literature to support the routine use of functional MRI (fMRI) in evaluation of post-traumatic head injury.


Head Trauma Child PCAs

Head Trauma Child PCAs. Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.


Head Trauma Child PCAs

Head Trauma Child PCAs. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Head Trauma Child PCAs

Head Trauma Child PCAs. Appropriateness Category Names and Definitions Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging


Head Trauma Child PCAs

Head Trauma-Child


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Introduction/Background Nonischemic cardiomyopathies (NICMs) encompass a broad spectrum of disorders of the myocardium associated with mechanical or electrical dysfunction leading to inappropriate ventricular hypertrophy or dilation, without evidence of ischemia [1]. Generally, valvular, hypertensive, and congenital diseases are treated separately from the NICM discussed here. The myocardial involvement can be either primary (genetic, acquired, or mixed) or secondary to a systemic disease process [2]. NICM can also be classified into distinct morphological and functional types, each of which can be subclassified as familial or nonfamilial types [3]. In this document, we have adapted this classification with five variants of nonischemic myocardial diseases: 1) hypertrophic cardiomyopathy (HCM); 2) restrictive cardiomyopathy or infiltrative diseases; 3) dilated cardiomyopathy (DCM) or unclassified cardiomyopathy; 4) arrhythmogenic cardiomyopathy (arrhythmia of ventricular origin); and 5) inflammatory cardiomyopathy [2]. With increasing availability and use of genetics, it is now known that cardiomyopathies do not fit into specific morphological and functional phenotypes as discussed above, and there is tremendous genetic heterogeneity. The recently proposed MOGE(S) nosology system provides a more comprehensive classification of cardiomyopathies, describing the morphofunctional phenotype (M), organ (O), genetic inheritance pattern (G), etiological annotation (E), and functional status (S) [4].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . NICM has an approximate prevalence of 0.02% with an annual death rate of 25,000 in the United States [2]. In adults, the prevalence of HCM is 1:250 to 500, DCM is 1:250 to 500, and arrhythmogenic right ventricular cardiomyopathy (ARVD) is 1:2,000 to 5,000 [5], whereas these are uncommon in children. Clinical presentation is variable, including heart failure (HF), arrhythmia, sudden death, and acute chest pain. Common presentations include dyspnea, edema, ascites, chest discomfort palpitations, and syncope. In patients with clinical HF, a primary cardiomyopathy is diagnosed in 2% to 15% of patients, whereas in some large-scale trials, patients with nonischemic HF accounted for 18% to 53% of the study population [6]. Acute presentation with chest pain, elevated cardiac enzymes, and abnormal electrocardiogram (ECG) may be seen inflammatory cardiomyopathies. Unlike ischemic cardiomyopathy, the pathophysiology of NICM is usually unclear and multifactorial, the functional consequences are global, the prognosis is better, and the therapeutic response is different [2].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . The primary role of imaging in NICM is to characterize the disease and establish the specific etiology, which is essential for determining optimal management. Although patients with NICM require general treatment for HF or arrhythmia, therapy is often tailored, depending on the etiology. For example, iron-overload cardiomyopathy is


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . aMayo Clinic, Rochester, Minnesota. bPanel Chair, Cleveland Clinic Florida, Weston, Florida. cPanel Vice-Chair, Cleveland Clinic, Cleveland, Ohio. dMiami Cardiac and Vascular Institute and Baptist Health of South Florida, Miami, Florida. eUniversity of Utah, Department of Radiology and Imaging Sciences, Salt Lake City, Utah. fUniversity of Wisconsin, Madison, Wisconsin. gUniversity of Iowa Hospitals and Clinics, Iowa City, Iowa. hToronto General Hospital, University of Toronto, Toronto, Ontario, Canada. iThe Ottawa Hospital, University of Ottawa, Ottawa, Ontario, Canada. jQueen's University, Kingston, Ontario, Canada; Cardiology expert. kNorthwestern University Feinberg School of Medicine, Chicago, Illinois; Society for Cardiovascular Magnetic Resonance. lUniversity of Alabama at Birmingham, Birmingham, Alabama. mUniversity of Virginia Health System, Charlottesville, Virginia; Society of Cardiovascular Computed Tomography. nWisconsin Heart Hospital, Milwaukee, Wisconsin; Nuclear cardiology expert. oJohns Hopkins Medical Institute, Baltimore, Maryland. pSpecialty Chair, UT Southwestern Medical Center, Dallas, Texas.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Reprint requests to: publications@acr.org


Nonischemic Myocardial Disease

Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . treated with chelation therapy; cardiac sarcoidosis is treated with high-dose corticosteroids; cardiac amyloidosis is treated with chemotherapy for light-chain amyloidosis (AL type) and novel therapies for transthyretin type; Fabry disease is treated with enzyme replacement therapy; and severe HCM or endomyocardial fibrosis is treated with surgery [2]. An endomyocardial biopsy may be required for definitive diagnosis in some cases; however, it is an invasive procedure and the yield may be low because of the patchy nature of disease processes. In unexplained cardiomyopathy, the final diagnosis based on biopsy differed from initial diagnosis in 31% of patients, and endomyocardial biopsy made the final diagnosis in 75% of these cases [9]. Imaging is also helpful for quantification of the disease process, risk stratification, prognosis, and monitoring response to therapy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . All elements are essential: 1) timing, 2) reconstructions/reformats, and 3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Chest Radiography Chest radiography can provide information on HF and vascular abnormalities; however, there is no specific role for radiography in characterizing the different types of NICM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Echocardiography provides information on ventricular function (global/regional, systolic/diastolic), volumes, mass, thickness, as well as valvular function. The morphology can be assessed, although it is limited in the evaluation of the right ventricle (RV). With the use of advanced techniques such as 3-D echocardiography, further subtyping of NICM is possible. Myocardial deformation can be evaluated using tissue Doppler imaging and speckle-tracking (2-D or 3-D). Abnormal global longitudinal strain enables detection of subclinical left ventricle (LV) dysfunction in several disease entities [11]. Doppler metrics are useful in evaluation of diastolic dysfunction, especially in restrictive cardiomyopathies and HCM [12]. However, routine echocardiography does not have tissue characterization capabilities. Contrast echocardiography can be used in the quantification of ventricular volumes and EF as well as regional wall motion when the routine images are suboptimal. It is also used in the evaluation of noncompaction, thrombus aneurysm, and apical lesions such as apical variant HCM, stress-induced cardiomyopathy, and endocardial fibroelastosis [13].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Cardiac CT Coronary CTA has a limited role in the evaluation of NICM, predominantly for excluding coronary artery disease (CAD) as the etiology of HF [15]. Cardiac CT can be used in the evaluation of morphology, characterization, and quantification of function in patients when echocardiography is suboptimal because of poor acoustic windows and MRI is suboptimal because of artifacts. The function and volumes obtained from CT correlate with other


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease modalities including MRI [16,17]. With retrospective ECG-gated acquisition, dynamic and functional information can be obtained. First-pass myocardial perfusion can be used to evaluate for ischemia. Delayed iodine- enhancement imaging can show variable patterns of enhancement in NICM, albeit at a lower contrast-to-noise ratio compared with MRI. Similar to MRI, extracellular volume (ECV) can be quantified with CT either using a single- or dual-energy CT technique [18]. CT strain imaging to quantify regional function [19] and CT evaluation of diastolic function are not routinely used in clinical practice [20]. Coronary calcium score is used for risk stratification of CAD in asymptomatic patients and does not have a specific role in evaluation of NICM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Coronary Arteriography Coronary arteriography is used to evaluate CAD as a cause of HF, especially in high-risk patients. Right and left heart catheterizations are useful in pulmonary hypertension, providing cardiac hemodynamics and prognostic value. Right heart and simultaneous right and left heart catheterization is useful in distinguishing restrictive cardiomyopathies from constrictive pericarditis [31]. A ventriculogram can be used to evaluate associated regional wall motion abnormalities (RWMA). Endomyocardial biopsy is used to establish etiology in cases that are indeterminate after imaging.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Discussion of Procedures by Variant Variant 1: Suspected hypertrophic cardiomyopathy. Ischemic cardiomyopathy already excluded. Initial imaging. HCM is an inherited myocardial hypertrophy with heterogeneous phenotypic expression (asymmetric septal, apical, mid ventricular, lateral wall, mass-like, and concentric types) [32]. Patients with HCM can present with diastolic dysfunction, LV outflow tract (LVOT) obstruction, ischemic chest pain, arrhythmias, or sudden cardiac death [33]. Occasionally, clinical symptoms are produced by papillary muscle abnormalities (anomalous chordal attachment to the base of anterior leaflet, double bifid muscles, apical displacement, hypermobility, elongated anterior mitral leaflet) without significant myocardial hypertrophy [34]. Asymptomatic family members of HCM often undergo imaging as a screening test.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary There is no relevant literature to support the use of coronary arteriography for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary with Ventriculography There is no relevant literature to support the use of coronary arteriography with ventriculography for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Chest There is no relevant literature to support the use of CT chest for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Coronary Calcium There is no relevant literature to support the use of CT coronary calcium for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Heart Function and Morphology Cardiac CT can be used in the evaluation of morphology and function in patients with suboptimal echocardiography. CT can provide accurate measurements of myocardial thickness. Myocardial fibrosis can be demonstrated and quantified in delayed-enhancement images with substantial agreement with MRI [36-38].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CTA Coronary There is no relevant literature to support the use of CTA in the evaluation of HCM when ischemic cardiomyopathy has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . FDG-PET/CT Heart There is no relevant literature to support the use of FDG-PET/CT heart for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Chest There is no relevant literature to support the use of MRI chest for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Function and Morphology MRI provides comprehensive information for the evaluation of HCM, including the morphology, location, distribution, and extent of hypertrophy and fibrosis [39]. MRI is superior to echocardiography in recognizing areas of segmental hypertrophy, which may be missed or underestimated with echocardiography, particularly the LV apex, the RV anterior free wall, and the LV inferoseptum [39,40]. RV hypertrophy is seen in a third of


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease patients [40]. MRI is more accurate than echocardiography in quantifying the myocardial thickness, which is an important prognostic indicator for myectomy [39]. LVOT obstruction (seen in one-third of patients with HCM and provocable in another third), systolic anterior motion of the mitral valve and mitral regurgitation may be seen in asymmetric basal septal type of HCM [33], although the quantification of flow acceleration due to LVOT obstruction is inferior when using MRI compared with echocardiography. MRI also helps in risk stratification and identification of patients who will benefit from primary prevention with ICD, primarily by the use of LGE. LGE is seen in up to 50% to 80% of HCM patients, with the extent of LGE correlating directly with adverse prognosis [39]. HCM patients with LGE have a 7-fold risk for nonsustained ventricular tachycardia, and extensive LGE >15% of LV mass is a marker for sudden death [39]. Apical aneurysm and massive hypertrophy >30 mm are also high-risk factors for sudden cardiac death [39]. Elevated native T1 and ECV measurements may be seen in HCM. One study showed that native T1 has 100% sensitivity, 96% specificity, and 98% accuracy in distinguishing healthy from diseased myocardium, including HCM [41,42]. Another advantage of MRI is its ability to evaluate papillary muscle abnormalities, which require different surgical management [34,43]. MRI is also useful in follow-up after treatment such as myectomy or septal ablation. MRI is used to screen family members with myocardial crypts, elongated mitral leaflets, delayed relaxation, high EF, and LGE seen in gene-positive, phenotype-negative patients [40].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Anderson-Fabry disease presents with concentric LV thickening but may occasionally be asymmetric. Mid myocardial or subepicardial LGE is seen in the basal inferolateral segment of the LV, unlike HCM, wherein LGE is seen anywhere. There is no systolic anterior motion of the mitral valve or LVOT obstruction in Anderson-Fabry disease [35]. Low native T1 values are seen in Fabry disease because of sphingolipid deposition, often prior to the onset of structural and functional abnormalities [44]. With development of fibrosis, long native T1 and elevated ECV values can be seen. High T2 values, RV involvement, valve thickening, and lower global longitudinal strain can also be seen [45]. Danon disease also shows concentric LV thickening with edema and stress perfusion defect. LGE is usually in a mid myocardial distribution, less often in a subendocardial and transmural pattern in anterolateral and inferior segments of the LV, often with sparing of septum [46,47].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Inotropic Stress There is no relevant literature to support the use of MRI heart inotropic stress for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Vasodilator Stress Reduced myocardial perfusion due to microvascular dysfunction is a poor prognostic factor in HCM. This may be seen even in areas without LGE, both in adults and children [48,49]. There is no evidence to support the use of MRI heart vasodilator stress for the evaluation of HCM when ischemic cardiomyopathy has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transesophageal There is no relevant literature to support the use of transesophageal echocardiography for the evaluation of HCM.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Resting Echocardiography is usually the initial imaging test in most patients with HCM. It is used in the evaluation of morphology, distribution, and quantification of HCM. Contrast echocardiography improves characterization of apical type of HCM [50]. Echocardiography is the preferred technique for the quantification of LVOT pressure gradient, which is a factor in selecting patients for myomectomy, as well as the assessment of systolic anterior motion, mitral regurgitation, and papillary muscle abnormalities. It can quantify LV systolic function, diastolic function, and left atrial volume. Decreased myocardial strain can be identified using speckle-tracking echocardiography [50]. Stress maneuvers, including a Valsalva maneuver in sitting, semisupine, and standing


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease positions can be used to provoke LVOT gradients that may not be seen in resting states [51]. It is also the first- line test for screening, such as in the risk assessment of sudden cardiac death in competitive athletes [50].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Stress Exercise stress echo is used to assess provocable LVOT gradient if resting gradient is not severe. It is also useful in the assessment of worsening mitral regurgitation [51].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Variant 2: Suspected restrictive cardiomyopathy or infiltrative disease. Ischemic cardiomyopathy already excluded. Initial imaging. Infiltrative disease is characterized by deposition of abnormal substances in the myocardium, resulting in myocardial thickening or dilation and restricted ventricular filling. Amyloidosis, Anderson-Fabry disease, acute sarcoidosis, Danon disease, endomyocardial fibrosis, oxalosis, mucopolysaccharidoses, and Friedrich ataxia result in myocardial thickening, whereas chronic sarcoidosis, scleroderma, and iron overload result in myocardial thinning [52]. Cardiac amyloidosis is usually of AL type or transthyretin-related amyloidosis (ATTR type), resulting in myocardial and valvular thickening and presenting with HF or arrhythmia. Myocardial involvement occurs in 25% of patients with systemic sarcoidosis in the United States [53]. Cardiac sarcoidosis is characterized by myocardial infiltration with noncaseating granulomas and presents with conduction abnormalities, arrhythmias, sudden cardiac death, HF, pericardial effusion, or ventricular aneurysms [2]. Diagnosis is based on the Japanese Ministry of Health and Welfare guidelines [54] or expert consensus recommendations [55]. Siderotic cardiomyopathy is characterized by iron deposition from frequent blood transfusions and altered iron hemostasis in hemoglobinopathy patients. Siderotic cardiomyopathy presents in advanced stages with HF, conduction abnormalities, or sudden death [2]. Scleroderma involves the heart in 80% (in autopsy) of cases, manifesting as HF, arrhythmia, CAD, peripheral vascular disease, or sudden death [2]. Endomyocardial fibrosis (Loeffler endocarditis in nontropical regions) is a spectrum of hyperesoinophlic syndrome (eosinophils >1,500/mm3; >6 months), with cardiac involvement seen in 50% of these patients [56]. There is an early necrotic phase followed by thrombotic and fibrotic phases. Myocardial oxalosis presents with LV thickening, heart block, and conduction abnormalities. Friedreich ataxia is characterized by mitochondrial iron accumulation, with cardiomyopathy seen in 63% of these patients [52]. Mucopolysaccharidoses has variable phenotypic expression. Infiltrative disease is generally evaluated with history, clinical examination, ECG, serology, and imaging tests [52]. Endomyocardial biopsy may be ultimately required for definitive diagnosis.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary There is no relevant literature to support the use of coronary arteriography for the evaluation of restrictive cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary with Ventriculography There is no relevant literature to support the use of coronary arteriography with ventriculography for infiltrative cardiac diseases. Right heart catheterization is used for the evaluation of hemodynamics, which is useful in the diagnosis of pulmonary hypertension and has prognostic value. In addition, right and left heart catheterization can be used to evaluate for constrictive pericarditis, which often has to be distinguished from restrictive cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Chest There is no relevant literature to support the use of CT chest for evaluation of restrictive cardiomyopathy. CT chest may show mediastinal lymphadenopathy and lung changes in systemic sarcoidosis. Pericardial calcification points toward a pericardial constriction rather than restrictive cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Coronary Calcium There is no relevant literature to support the use of CT coronary calcium for the evaluation of restrictive cardiomyopathy. Incidental pericardial calcification points toward a pericardial constriction rather than restrictive cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Heart Function and Morphology Abnormal first-pass perfusion, delayed iodine enhancement, and high ECV values have been shown with CT in cardiac amyloidosis [57,58]. Subepicardial or mid myocardial delayed iodine enhancement has also been shown to identify cardiac sarcoidosis [59]. Pericardial calcification points toward a pericardial constriction rather than restrictive cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease CTA Coronary There is no relevant literature to support the use of coronary CTA for the evaluation of restrictive cardiomyopathy when ischemic cardiomyopathy has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nuclear Medicine Tc-DPD and Tc-PYP have high specificity in the diagnosis of cardiac amyloidosis. Ga-67 scintigraphy shows high uptake in cardiac sarcoidosis, with the intensity correlating with degree of inflammation [55]; however, it has low sensitivity [55]. Perfusion defects seen in thallium-201 and Tc-99m myocardial scintigraphy, as well as Rb- 82, can be distinguished from ischemia by using PET/CT [55].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . FDG-PET/CT Heart FDG-PET performed after suppressing normal glucose metabolism shows high uptake in cardiac sarcoidosis, with reverse distribution in thallium-201 scans. FDG-PET had an 82% to 100% specificity and 39% to 91% specificity in the diagnosis of cardiac sarcoidosis [54]. FDG has higher sensitivity than Ga-67 scintigraphy, although Ga-67 scintigraphy is included in the imaging criteria [54]. A meta-analysis showed 89% sensitivity, 78% specificity, and area under the receiver operator characteristic curve of 93% for diagnosis of cardiac sarcoidosis [60]. The FDG activity can be quantified to improve the diagnostic accuracy, assess disease activity, and evaluate prognosis [60]. Simultaneous PET/MRI has been shown to be feasible with diagnostic image quality to evaluate cardiac sarcoidosis [61].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Chest There is no relevant literature to support the use of MRI chest for the evaluation of restrictive cardiomyopathy. MRI chest may show mediastinal lymphadenopathy and lung changes in systemic sarcoidosis.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Function and Morphology MRI has distinctive appearances in several infiltrative disorders and restrictive cardiomyopathies. Cardiac amyloidosis produces concentric thickening of ventricles, atria, interatrial septum, and valves, with low signal in T2-weighted images [62]. Diffuse subendocardial LGE is seen in early stages, which progresses to transmural LGE. Abnormal LGE has a pooled specificity of 92% and sensitivity of 85% in the diagnosis of cardiac amyloidosis [63]. Dark blood pool and earlier nulling of myocardium is also seen in cardiac amyloidosis. High native T1 and ECV values are more sensitive than LGE and reliably distinguish amyloidosis from HCM [64]. MRI can distinguish AL and ATTR types, with ATTR amyloidosis showing more LV thickening and mass, lower left ventricular ejection fraction (LVEF), greater LGE, more transmural LGE, and lower T1 values than the AL type [64]. An LGE-based scoring system was shown to have 87% sensitivity and 96% specificity in distinguishing AL and ATTR amyloidosis [64]. LGE, T1, and ECV abnormalities all correlate with prognosis in cardiac amyloidosis [65]. Transmural LGE is a predictor of adverse events including death [66]. Postcontrast difference in T1 between subepicardium and subendocardium of >23 ms predicts mortality with high accuracy [67]. Low T2 value and short T1 in >50% of myocardium T1 scout image are also poor prognostic factors [2].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI has sensitivity of 75% to 100% and specificity of 75% to 77% in the diagnosis of cardiac sarcoidosis [54,68,69]. In the acute stage, MRI shows wall thickening, high T2 signal (due to edema), high native T1 and T2 values, RWMA, and LGE. LGE is more common in the basal septal and lateral walls of the LV in a subepicardial or mid myocardial distribution. In the chronic stage, wall thinning, aneurysms, RWMA, and LGE may be seen (mid myocardial, subepicardial, and/or transmural) [70]. LGE correlates with prognosis with a hazard ratio of 32 for lethal events [71]. There is a good response to steroids in patients with lower LGE at initiation of therapy [72]. High native T1 and T2 values provide higher discriminatory accuracy compared with traditional criteria and help in evaluating the response to treatment [73].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Myocardial iron deposition can be reliably quantified using T2* techniques. Myocardial T2* <20 ms indicates significant iron deposition and <10 ms indicates advanced iron deposition with high accuracy [74]. T1-mapping is more reproducible and sensitive, with low T1 values seen in 32% of patients with normal T2* [75]. With appropriate use of chelation therapy, improvements in T2* and LVEF has been reported [76]. The use of MRI has resulted in improved outcomes with death rates declining to 2.3 per 1,000 compared with 7.9 per 1,000 prior to the use of MRI [76].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Linear mid myocardial LGE is seen in 66% of patients with scleroderma, either in the ventricular septum or the LV free wall at the basal and mid levels [77]. Patchy RV insertion enhancement can be seen in 17% of patients (76). LGE is more severe in patients with longer duration of Raynaud disease [78]. High native T1 and ECV values are seen in asymptomatic patients with no known cardiac involvement, due to inflammation, and are


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease associated with low diastolic and systolic strain rates [78]. Focal edema and fibrosis are also seen. Pericarditis, pericardial effusion, and adhesions may be seen.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . In endomyocardial fibrosis, the apical wall is thickened and has a high T2 signal. A characteristic 3-layered pattern of LGE is seen with an inner layer of dark nonenhancing thrombus, middle layer of subendocardial LGE due to diffuse fibrosis (from LVOT to apex), and outer layer of nonenhancing normal myocardium [56,79]. LGE was associated with poor functional class and higher chance of surgery [56]. In Churg Strauss syndrome, LGE is seen in apical and mid segments and in anterior and anteroseptal segments in a subendocardial distribution. In myocardial oxalosis, concentric LV thickening and diastolic dysfunction are seen. In Friedreich ataxia, concentric or asymmetric LV thickening, diastolic dysfunction, and fibrosis may be seen. Mucopolysaccharidoses have variable expression, including asymmetric septal thickening, mitral or aortic valve pathologies, and normal EF [52].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Inotropic Stress There is no relevant literature to support the use of MRI heart inotropic stress for the evaluation of restrictive cardiomyopathy. Ischemia has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Vasodilator Stress There is no relevant literature to support the use of MRI heart vasodilator stress for the evaluation of restrictive cardiomyopathy. Ischemia has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transesophageal There is no relevant literature to support the use of transesophageal echo for the evaluation of restrictive cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Resting Echocardiography is often the initial imaging test that identifies possible restrictive cardiomyopathy. Echocardiography can evaluate diastolic function with high accuracy, which is often impaired in early stages of several restrictive cardiomyopathies. Decreased systolic and diastolic mitral annular velocities, restrictive pattern in mitral valve such as high velocity (E wave), short deceleration time and low late diastolic filling (A wave), and elevated filling pressures (E/e ratio) are seen [12,80]. Before the widespread use of harmonic imaging, the myocardium was described as having a characteristic speckled (starry sky) appearance [64], a finding now considered obsolete with the widespread use of harmonic imaging techniques. A relative apical sparing of longitudinal strain of 1.0 (average apical longitudinal strain/average of basal and mid longitudinal strain) has a high sensitivity (93%) and specificity (82%) in distinguishing cardiac amyloidosis from controls [81]. Apical thickening may be seen in endomyocardial fibrosis. In sarcoidosis, echocardiography shows ventricular septal thickening and diastolic dysfunction in the acute phase but thinning in the chronic phase with associated RWMA, aneurysm, and global systolic dysfunction [55].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Stress There is no relevant literature to support the use of echocardiography transthoracic stress for the evaluation of restrictive cardiomyopathy. Ischemia has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Variant 3: Suspected nonischemic dilated and unclassified cardiomyopathy. Ischemic cardiomyopathy already excluded. Initial imaging. DCM is characterized by a dilated ventricle and global systolic dysfunction. Ischemia is the most common cause of DCM and is excluded as discussed above. Approximately 50% of nonischemic DCM is idiopathic and is usually seen in a younger age group [2]. Other etiologies include toxins, familial inheritance, infections, infiltrative disorders, autoimmune conditions, metabolic derangements, and arrhythmias. Alcoholic cardiomyopathy is seen in heavy drinkers with probable genetic susceptibility, more common in men 30 to 55 years of age [2,82]. Chemotherapeutic agents such as anthracyclines, tyrosine kinase inhibitors, trastuzumab, and interferons induce cardiomyopathy. There is a higher risk for cardiomyopathy with higher cumulative dose of chemotherapy, combination with other chemotherapeutic agents, associated radiation, and higher age. Acute cardiac changes can be seen as early as in a few hours after initiation, whereas late changes may be seen over decades with LV dilation and EF decrease, which limits the aggressive use of chemotherapy [83].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Peripartum cardiomyopathy is an idiopathic cardiomyopathy seen either in the late stage of pregnancy or in the first 5 months after delivery [84]. It is seen in 1 in 2,500 to 4,000 births in the United States [84]. Risk factors for peripartum cardiomyopathy include age >30 years, nonwhite background, multiparity, poor socioeconomic status,


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease prolonged tocolytic therapy, hypertension, preeclampsia, and cocaine use [85]. These patients are evaluated with ECG, serological biomarkers, and imaging tests. Endomyocardial biopsy may be needed to exclude myocarditis. Several types of inherited muscular dystrophies can also produce DCM. These muscular dystrophies present with HF, arrhythmia, or sudden death by thromboembolism.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . There are several unclassified NICMs. LV noncompaction is characterized by prominent trabeculations due to persistent embryonic sinusoids, leading to LV failure, thromboembolism, and arrhythmias [86]. Stress-induced cardiomyopathy (also known as Takotsubo cardiomyopathy) is characterized by transient LV systolic dysfunction attributed to catecholamine release, possibly following a stressful event. It presents similarly to acute myocardial infarction with chest pain, ST-segment elevation on ECG, and elevated cardiac enzymes. It accounts for 2% of myocardial infarction with nonobstructive coronary arteries (MINOCA) [87]. One study found that incidental CAD was found in 10% of patients with stress-induced cardiomyopathy [88]. Diagnosis is made based on the Mayo Clinic or InterTAK diagnostic criteria [89]. LVOT obstruction, arrhythmia, shock, ventricular rupture, thrombus, and death may also be seen [2]. Cardiomyopathy can be seen in cirrhotic patients, independent of alcohol exposure. Patients with DCM are evaluated with history, clinical examination, lab tests, ECG, coronary angiography, and imaging.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary There is no literature to support the use of coronary arteriography for the evaluation of nonischemic dilated or unclassified cardiomyopathy when ischemia has already been excluded. Stress-induced cardiomyopathy has been reported to be triggered by acute myocardial ischemia [90].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary with Ventriculography There is no relevant literature to support the use of coronary arteriography with ventriculography for the evaluation of nonischemic dilated or unclassified cardiomyopathy when ischemia has already been excluded. If performed, RWMA not explained by a culprit lesion may be seen in left ventriculography [90]. With LV apical ballooning patterns and normal coronaries on CTA or coronary angiography, stress-induced cardiomyopathy can be confirmed, except in patients with red flags for acute myocarditis, in which MRI is indicated.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Chest There is no relevant literature to support the use of CT chest for the evaluation of nonischemic dilated or unclassified cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Coronary Calcium There is no relevant literature to support the use of CT coronary calcium for the evaluation of nonischemic DCM or unclassified cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Heart Function and Morphology CT can be used for morphological and functional evaluation in patients in whom echocardiogram is suboptimal. CT is accurate in distinguishing idiopathic from ischemic DCM [91]. CT has been shown to be accurate in the diagnosis and characterization of LV noncompaction using the standard MRI criteria of end-diastolic noncompacted LV myocardial thickness to compacted LV myocardial thickness ratio of >2.3 [92]. CT can show the abnormalities of stress-induced cardiomyopathy, including absence of delayed enhancement [93,94].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CTA Coronary There is no relevant literature to support the use of CTA coronary for the evaluation of nonischemic DCM or unclassified cardiomyopathy when ischemic cardiomyopathy has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . FDG-PET/CT Heart There is no relevant literature to support the use of FDG-PET/CT as the first-line imaging modality in the evaluation of nonischemic or unclassified cardiomyopathy. One study found that nearly 50% of patients with unexplained cardiomyopathy and arrhythmia demonstrate focal inflammation in FDG-PET/CT, which is indicative of inflammatory cardiomyopathy [96].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease MRI Chest There is no relevant literature to support the use of MRI chest for the evaluation of nonischemic DCM or unclassified cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Function and Morphology In DCM, MRI helps in establishing the etiology and quantifying the abnormalities. Dilated ventricles, secondary tricuspid and/or mitral regurgitation due to annular dilation, regional ventricular dysfunction, ventricular wall thinning, and eccentric remodeling are seen. Myocardial infarct is diagnosed if there is subendocardial or transmural pattern of LGE in a vascular distribution. In idiopathic DCM with nonobstructed coronary arteries, linear or patchy mid myocardial LGE, primarily at the base and mid septum, is seen in 28% of patients. No LGE is seen in 59%. Subendocardial LGE is seen in 13% of these patients that is either due to atypical nonischemic fibrosis or silent ischemia from coronary embolus or recanalized plaque rupture [97]. Using LGE, 19% of additional patients gained an indication for ICD, and 11% avoided a previously planned ICD compared with standard of care [98]. High T1 and ECV values show more sensitivity than LGE [68]. Native T1 value, ECV value, presence and extent of LGE, and EF correlate with adverse prognosis [99].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . In chemotherapy cardiomyopathy, MRI helps in arbitrating discrepancies between imaging modalities, which may affect management. A reduction of EF by >10% or a reduction of EF >5% in symptomatic individuals is diagnostic of this entity (as long as the resultant EF is <53%) [83,100]. Early markers of cardiac involvement include elevated LV end-systolic volume (seen within 1 month); increased LV mass (due to edema); RWMA (decreased mid wall circumferential strain); high T1, T2, and ECV values; high signal in T2-weighted images (edema); and EGE [83]. Patients with edema are more likely to have right ventricular ejection fraction (RVEF) reduction at follow-up [100]. LGE can be seen in 0% to 100% of patients, either in mid myocardial or subepicardial distribution and rarely diffuse, indicating irreversible damage [101]. In late-onset cardiomyopathy in cancer survivors, abnormal or subnormal LVEF and RVEF, as well as high LV volumes without LGE, were seen at a median of 7.8 years after anthracycline therapy [102]. Increased ECV has been shown in cancer survivors [100]. LGE has been shown in 9% to 18% in mid myocardial, subepicardial, or RV insertion point distributions [101].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . In peripartum cardiomyopathy, MRI provides additional information pertaining to diagnosis and prognosis, which are not obtained in echocardiography. Gadolinium contrast is avoided until after delivery. LV dilation, global LV systolic dysfunction, RV dysfunction, and LGE are seen [84]. LGE is seen in 40% in a subepicardial or mid myocardial distribution in the anterior and anterolateral LV segments (occasionally subendocardial or transmural), more commonly in scans taken >7 days after the acute phase [84]. High T1 and T2 values and EGE are also seen in the acute stages [103]. Patients with LGE showed higher decompensation and did not regain LVEF [84].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Muscular dystrophies may present with ventricular dilation, and mid myocardial/subepicardial pattern of LGE, with occasional noncompacted myocardium. LGE may be present when echocardiography is still normal [104] and is an adverse prognostic determinant [84]. A higher amount of LGE is associated with lower LVEF, but LGE has a variable association with arrhythmia [104]. With longer duration of steroid treatment, lower increase in fibrosis burden was seen over time [105]. T1 and ECV values are also abnormal, which were associated with arrhythmia. Strain imaging shows abnormalities in earlier stages, before onset of overt HF, shows better serial decline in LV function, and provides reliable monitoring of progression of dystrophy [106]. LGE is also seen in mutation carriers [104].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Nonischemic Myocardial Disease used MRI diagnostic criteria for noncompaction, indicating that these criteria have poor specificity. This may, therefore, represent a variant anatomical phenotype than cardiomyopathy [112,113].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI in stress-induced cardiomyopathy shows reversible global systolic dysfunction and LV apical ballooning with normal or hyperkinetic basal segments and akinetic/hypokinetic apical segments. There are also reverse and mid ventricular variants. RV is involved in 40% of cases, which is associated with a worse prognosis [114]. Myocardial edema may be present, leading to a high signal in T2-weighted images, high native T1, and high T2 values, typically confined to the abnormal segment [115]. Edema diffuses more than myocardial ischemia and decreases within a few weeks unlike myocardial ischemia, which may take up to 3 months to diminish [115]. Typically, there is no LGE. However, recent studies have shown that LGE may be present in up to 40% of patients, typically in the areas of RWMA. This is usually of lower signal intensity (<5 SD above remote normal myocardium) than the LGE of myocardial infarction [87]. These patients may have irreversible damage with worse prognosis and longer recovery time [116,117]. MR diagnosis of stress-induced cardiomyopathy is made based on a typical pattern of LV dysfunction in a noncoronary pattern, myocardial edema corresponding to areas with RWMA, absence or insignificant LGE (<5 SD above remote normal myocardium), and markers for myocardial inflammation (EGE ratio > 4.0) [114]. MRI is superior to echocardiography in evaluating the RV involvement and complications [114]. Functional improvement occurs usually in 3 to 4 months but may take up to 12 months in 5% of patients; it may recur in 5% to 11% of patients [87]. Although stress-induced cardiomyopathy was typically thought to be completely reversible, recent literature indicates long-term clinical consequences [118].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Inotropic Stress There is no relevant literature to support the use of MRI heart inotropic stress for the evaluation of nonischemic DCM or unclassified cardiomyopathy when ischemia has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Vasodilator Stress There is no relevant literature to support the use of MRI vasodilator stress for the evaluation of nonischemic DCM or unclassified cardiomyopathy when ischemia has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transesophageal There is no relevant literature to support the use of transesophageal echocardiography for the evaluation of nonischemic DCM or unclassified cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Resting Echocardiography can evaluate the function in several types of nonischemic DCM. It does not provide tissue characterization to identify the specific cause of cardiomyopathy, but the presence of systolic dysfunction in patients on chemotherapy, postpartum, and alcoholic patients is suggestive of cardiomyopathy.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . In chemotherapy, a reduction of EF by >10% or a reduction of EF >5% in symptomatic individuals is diagnostic of this entity (as long as the resultant EF is <53%). Calculation of LVEF by 3-D echocardiography is more reproducible and accurate than by 2-D echocardiography and is preferred for the evaluation and longitudinal assessment of patients treated with chemotherapy [100]. A 10% to 15% reduction of peak systolic global longitudinal strain by speckle-tracking echocardiography is the most useful parameter to predict cardiotoxicity [119]. Global radial and circumferential strains are abnormal in late survivors, but their clinical value is less proven [119]. Decreased global longitudinal strain with preserved EF is the most common echocardiographic abnormality in cancer survivors [100]. Echocardiography can confirm, quantify, and detect associated abnormalities and complications, as well as risk stratify patients [120].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . In LV noncompaction, echocardiography shows a 2-layered structure with prominent LV trabeculations (end- systolic ratio >2) and deep perfused intertrabecular recesses in color Doppler [86,121]. The sensitivity and reproducibility of echocardiography is improved by using LV contrast [122]. LV strain is decreased in noncompacted as well as compacted segments [122]. Transient reversible global systolic dysfunction as well as RWMA (apical, mid ventricular, basal, or focal in anterolateral segment) are seen in stress-induced cardiomyopathy [95]. Wall motion abnormalities show circular pattern in speckle echocardiography with improved detection using IV contrast [95].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Stress There is no relevant literature to support the use of echocardiography transthoracic stress for the evaluation of nonischemic DCM or idiopathic cardiomyopathy when ischemia has already been excluded.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary There is no relevant literature to support the use of coronary arteriography for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Arteriography Coronary with Ventriculography Imaging is initially performed with noninvasive tests such as MRI or CT. However, the 2010 criteria specifies RV angiographic criteria for ARVD, including regional RV akinesia, RV dyskinesia, or RV aneurysm [123].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Chest There is no relevant literature to support the use of CT chest for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Coronary Calcium There is no relevant literature to support the use of CT coronary calcium for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CT Heart Function and Morphology ECG-gated cardiac CT shows wall motion abnormalities and allows quantification of ventricular volumes and function. RV myocardial fat may be seen but is nonspecific. A single study showed that a CT-based scoring system based on fatty tissue, bulging appearance, and dilation of RV had 87% sensitivity, 94.4% specificity, positive predictive value of 87%, negative predictive value of 94.4%, and accuracy of 92.2% for diagnosis of definitive ARVD [127].


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . CTA Coronary There is no relevant literature to support the use of coronary CTA for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . FDG-PET/CT Heart There is no relevant literature to support the use of FDG-PET/CT for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Chest There is no relevant literature to support the use of MRI chest for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Inotropic Stress There is no relevant literature to support the use of MRI heart inotropic for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . MRI Heart Vasodilator Stress There is no relevant literature to support the use of MRI heart vasodilator stress for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transesophageal There is no relevant literature to support the use of transesophageal echocardiography for the evaluation of arrhythmogenic cardiomyopathies.


Nonischemic Myocardial Disease with Clinical Manifestations Ischemic Cardiomyopathy Already Excluded . Echocardiography Transthoracic Stress There is no relevant literature to support the use of echocardiographic transthoracic stress for the evaluation of arrhythmogenic cardiomyopathies.