Altered Mental Status Coma Delirium and Psychosis. examinations were ordered, with an overall critical result yield of 8.0%. CT head examinations performed for a complaint of AMS had a yield of 9.8% [25]. A study of 285 febrile elderly patients with AMS showed abnormal brain imaging in 16.5%. The most common neurological diagnoses in patients admitted to the ED were intracranial hemorrhage (ICH) and ischemic stroke [26]. Lower Glasgow Coma Scale, the presence of lateralizing sign, higher systolic blood pressure, and lower body temperature were significantly associated with abnormal brain imaging in febrile elderly patients with AMS [26].


Altered Mental Status Coma Delirium and Psychosis. The prevalence of delirium in the ED ranges from 7% to 35%. Four factors with strong associations with ED delirium are nursing home residence, cognitive impairment, hearing impairment, and a history of stroke [27]. There are a wide range of precipitating factors leading to delirium onset that make evaluation challenging, some of which are life threatening. These may be related to systemic disease, such as sepsis or infection, hypoxia, metabolic derangements, hypoglycemia, hyperglycemia, hyponatremia, hypothermia, acute myocardial infarction, neurologic disease including stroke, ICH, Wernicke encephalopathy (thiamine deficiency), central nervous system infection, seizure, surgery, trauma, drugs such as anticholinergic drugs, sedatives, narcotics, drug or alcohol withdrawal, polypharmacy, environmental factors from restraints, stress or pain, and sleep deprivation. There is relatively little evidence in the literature regarding appropriate use of neuroimaging with new onset delirium.


Altered Mental Status Coma Delirium and Psychosis. CT Head With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. In the setting of AMS, contrast- enhanced CT examinations can be considered if intracranial infection, tumor, or inflammatory pathologies are suspected. However, the use of contrast-enhanced head CTs as a first-line test in the acute setting does not add significant value over noncontrast head CT examinations [28].


Altered Mental Status Coma Delirium and Psychosis. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without intravenous (IV) contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. The reported detection of treatment-altering findings on head CT is very low in elderly patients with new onset delirium unless 1 of the following risk factors is present: focal neurologic deficit, history of recent falls or head injury, anticoagulation therapy, signs of elevated intracranial pressure, or significant deterioration of consciousness [8,38-40]. Acute pathology that resulted in a change of management was detected in a small proportion of patients on head CT, including ischemic and hemorrhagic stroke, subdural hematoma, subarachnoid hemorrhage (SAH), encephalitis or meningitis, and cerebral tumors. Therefore, the low diagnostic yield of CT in this setting must be weighed against the risk of possible, preventable morbidity [8,10], acknowledging that patients may not have clinical signs on examination that predict a focal pathology [34].


Altered Mental Status Coma Delirium and Psychosis. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. Altered Mental Status, Coma, Delirium, and Psychosis MRI Head Without and With IV Contrast MRI examinations without and with IV contrast may be performed if intracranial infection, tumor, inflammatory lesions, or vascular pathologies are suspected.


Altered Mental Status Coma Delirium and Psychosis. In patients with delirium, brain MRI without and with IV contrast may be helpful for the definitive characterization of a focal lesion identified on initial noncontrast CT or in patients with known cancer history [10].


Altered Mental Status Coma Delirium and Psychosis. In a simulated decision-making study using a prospective intensive care unit cohort, a panel of neurocritical experts first reviewed clinical information (without MRI) from 75 patients with acute disorder of consciousness patients and made decisions about diagnosis, prognosis, and treatment. Review of head MRI examinations led to changes in clinical management of 76% of patients including revised diagnoses in 20%, revised levels of care in 21%, improved diagnostic confidence in 43%, and improved prognostications in 33% [37]. However, decisions were revised more often with stroke (which commonly presents with focal neurological deficits) than with other brain injuries.


Altered Mental Status Coma Delirium and Psychosis. Many of the abnormal findings in the literature for this topic included small ischemic infarcts [29,35,36]. Notably, a retrospective study found that 70% of patients who had a missed ischemic stroke diagnosis presented with AMS [33]. MRI of the brain is complementary to an abnormal head CT for the evaluation of suspected intracranial mass lesions, intracranial infection, nonspecific regions of edema, ischemia, and cases of ICH when an underlying lesion is suspected [38]. MRI may also be considered as a first-line test in certain situations, such as a clinically stable patient with known malignancy, HIV, or endocarditis.


Altered Mental Status Coma Delirium and Psychosis. Noncontrast MRI examinations of the brain are usually sufficient in the assessment of intracranial complications related to hypertensive emergency, including posterior reversible encephalopathy syndrome.


Altered Mental Status Coma Delirium and Psychosis. In patients with new onset delirium, the reported yield of brain MRI is very low in the absence of a focal neurologic deficit or history of recent falls. In a small proportion of patients, brain MRI did reveal acute pathology possibly accounting for delirium, including ischemic and hemorrhagic stroke, subdural hematoma, SAH, septic emboli, encephalitis, meningitis, cerebral metastases, primary brain tumor, pineal tumor, and a large meningioma [34]. MRI may be helpful for further evaluation of an abnormality detected on noncontrast CT in the workup of new onset delirium, such as space-occupying lesions or infection.


Altered Mental Status Coma Delirium and Psychosis. CT Head With IV Contrast Contrast-enhanced CT examinations may be considered if clinical concern exists for progression of intracranial infection, such as abscesses or empyema, tumor, or inflammatory conditions. Advantages of CT are fast examination times and less susceptibility to motion artifact compared with MRI. Disadvantages of CT include less sensitivity in detection of acute ischemia and enhancement compared with MRI [30]. Overall, MRI is considered superior in this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. CT Head Without IV Contrast CT is the first-line imaging test of choice for evaluating suspected progressive ICH, mass effect, or hydrocephalus in the emergent setting. Noncontrast head CT examinations are able to depict possible complications of a wide variety of intracranial pathology, including progressive mass effect, increasing edema, hydrocephalus, new or enlarging ICH, and progressive ischemia. However, the literature search did not identify any studies regarding the


Altered Mental Status Coma Delirium and Psychosis. 6 Altered Mental Status, Coma, Delirium, and Psychosis


Altered Mental Status Coma Delirium and Psychosis. use of CT in the evaluation of acute or worsening mental status changes in a patient with known intracranial pathology.


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without and With IV Contrast MRI is the imaging test of choice in the evaluation of suspected progressive inflammatory conditions, such as multiple sclerosis or neuropsychiatric systemic lupus erythematosus. In the assessment of known ICH, MRI is usually not required unless there is suspicion for an underlying mass or lesion or if axonal shear injury is suspected. MRI without and with IV contrast may be performed if intracranial infection, tumor, inflammatory lesions, or vascular pathologies are suspected.


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without IV Contrast MRI is complementary to CT in the evaluation of suspected progression of intracranial mass lesions, infection, and ischemia and may be performed as a first-line test instead of CT. However, the literature search did not identify any studies regarding the use of MRI in the evaluation of acute or worsening mental status changes in a patient with known intracranial pathology.


Altered Mental Status Coma Delirium and Psychosis. Advantages of MRI include higher sensitivity for the detection of ischemia, encephalitis, subtle cases of SAH, and enhancement of pathology compared with CT and the potential to use advanced imaging applications that may provide critical information, such as diffusion-weighted imaging, MR perfusion, susceptibility-weighted sequences, and MR spectroscopy. Disadvantages of MRI include longer examination time, susceptibility to motion artifacts, and implanted devices that are not MRI safe [2].


Altered Mental Status Coma Delirium and Psychosis. Variant 3: Adult. Altered mental status. Suspected medical illness or toxic-metabolic cause. Initial imaging. Acute mental status changes may be triggered by a wide range of medical conditions, including drugs and intoxication, system or organ dysfunction, and metabolic or endocrine factors. This variant encompasses a subgroup of patients presenting with acute mental status changes at low risk of acute intracranial pathology.


Altered Mental Status Coma Delirium and Psychosis. CT Head With IV Contrast The literature search did not identify any studies regarding the use of contrast-enhanced CT relevant to this variant, and contrast-enhanced CT examinations are not performed as a first-line test in this setting.


Altered Mental Status Coma Delirium and Psychosis. CT Head Without IV Contrast ED physicians are moderately accurate at establishing the correct clinical diagnosis for the cause of AMS within the first 20 minutes of the patient encounter [15]. A large proportion of misdiagnoses in this study were deemed insignificant because of confusing various forms of isolated or mixed intoxication. Although CT head may be useful in this scenario, deferring head CT imaging while observing if intoxicated patients symptomatically improve may be a safe practice and may prevent the need for imaging in large percentage of intoxicated patients [39].


Altered Mental Status Coma Delirium and Psychosis. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without IV Contrast There may be unique instances where a brain MRI examination may be useful in confirming a suspected clinical diagnosis responsible for AMS, such as carbon monoxide poisoning, Wernicke encephalopathy (thiamine deficiency) [40], drug toxicity including medications (eg, methotrexate, metronidazole) and illegal drug use, central pontine myelinolysis, or additional metabolic disorders. However, the literature search did not identify any studies regarding the use of MRI relevant to this variant.


Altered Mental Status Coma Delirium and Psychosis. Altered Mental Status, Coma, Delirium, and Psychosis Variant 4: Adult. Altered mental status despite clinical management of known medical illness or toxic- metabolic cause. Initial imaging. This is a challenging clinical scenario in which common and treatable causes of AMS have been deemed unlikely, and a more exhaustive evaluation is required to find the precipitating cause of AMS. Clinical suspicion for a neurologic cause of AMS may be in an intermediate category.


Altered Mental Status Coma Delirium and Psychosis. CT Head With IV Contrast Contrast-enhanced CT examinations are usually not performed as a first-line test in this setting but may be considered as a second-line test to assess abnormalities found on the screening head CT and for patients unable or unwilling to have MRI [28]. Evidence guiding appropriate imaging recommendations in this variant is limited because most studies in the literature search sampled undifferentiated patient populations with a broad range of risk factors and are not directly applicable to this variant [2,29,31-33].


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without and With IV Contrast MRI examinations without and with IV contrast may be performed if intracranial infection, tumor, inflammatory lesions, or vascular pathologies are suspected. However, the literature search did not identify any studies regarding the use of contrast-enhanced MRI relevant to this variant.


Altered Mental Status Coma Delirium and Psychosis. Noncontrast MRI examinations of the brain are usually sufficient in the assessment of intracranial complications related to hypertensive emergency, including posterior reversible encephalopathy syndrome.


Altered Mental Status Coma Delirium and Psychosis. Variant 5: Adult. New onset psychosis. Initial imaging. This variant addresses the role of neuroimaging in the assessment for secondary causes of new onset psychosis in the ED or inpatient setting. Some of the reported organic causes of psychosis include tumors or infarcts in specific areas of the brain, such as the temporal lobe, systemic lupus erythematosus, encephalitis, multiple sclerosis, Wilson disease, Huntington disease, or metachromatic leukodystrophy [42-44].


Altered Mental Status Coma Delirium and Psychosis. Patients with new onset psychosis who have suspected stroke, focal neurologic deficit, seizure, head trauma, or headache should refer to the respective ACR Appropriateness Criteria as appropriate: ACR Appropriateness


Altered Mental Status Coma Delirium and Psychosis. CT Head With IV Contrast Contrast-enhanced CT is generally not helpful for new onset psychosis in the absence of focal neurologic deficits.


Altered Mental Status Coma Delirium and Psychosis. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario.


Altered Mental Status Coma Delirium and Psychosis. MRI Head Without and With IV Contrast Brain MRI without and with IV contrast may be performed for definitive characterization of a focal lesion identified on initial noncontrast CT examination or in patients with suspected autoimmune disorders, such as multiple sclerosis or neuropsychiatric lupus [44,46].


Altered Mental Status Coma Delirium and Psychosis. Altered Mental Status, Coma, Delirium, and Psychosis 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.


Altered Mental Status Coma Delirium and Psychosis. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Altered Mental Status Coma Delirium and Psychosis. Appropriateness Category Name 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 examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the


Fever Without Source or Unknown Origin Child. Although FWS is mostly self-limited and of little clinical concern, the burden on clinicians is to decide which children actually have a serious bacterial infection (SBI) that requires antibiotic treatment and even hospitalization [18,19]. Febrile neonates are at higher risk; the reported incidence of SBI in all febrile neonates presenting to emergency departments varies between 6% and 28% [17,20]. In children, the usual sources/causes of SBI are urinary tract infection, pneumonia, bloodstream infection, and meningitis. With the advent of vaccines for the most common pathogenic serotypes of H. flu and S. pneumonia, the incidence of SBI has dropped significantly [2,3,6,10,13,14]. Although it is implied by the definition of FWS that the etiology of fever is unknown, many studies and guidelines include children with respiratory symptoms [2,3,5,6,8,16,21-24]. For this reason, we were compelled to include in our guidelines for FWS children with respiratory symptoms.


Fever Without Source or Unknown Origin Child. Overview of Imaging Modalities A detailed and thorough history and physical examination is the most important component of the diagnostic evaluation of a child with FWS or FUO. Chest radiographs have a role in evaluation of occult pneumonia and should be performed in neonates with FWS and respiratory symptoms and in selected older children with high


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Fever Without Source or Unknown Origin Child. Discussion of Imaging Modalities by Variant Variants 1 and 2: Neonate younger than 1 month of age with FWS. In febrile neonates younger than 28 days, history and physical examination alone may not be able to completely exclude SBI, even in children who appear clinically well or mildly ill [40]. Therefore, a full sepsis workup is frequently performed. This includes complete blood count, blood culture, urinalysis and urine culture, lumbar puncture with evaluation of cerebrospinal fluid, and administration of antibiotics in the emergency department, followed by hospitalization pending results of cultures [2,3,8,9,22,28].


Fever Without Source or Unknown Origin Child. A chest radiograph is indicated in neonates with FWS and respiratory symptoms [3,21]. In addition, a chest radiograph in a septic-appearing neonate with FWS may disclose an occult pneumonia [6,8,16,28]. Some investigators advocate routine chest radiographs in all neonates with FWS because these infants are relatively immunocompromised compared with older infants and children, and the consequences of a missed SBI or occult infection are felt to be greater [6]. A chest radiograph can help exclude congenital or acquired cardiac disease in a child who is febrile and ill. However, the benefit of routine use of chest radiography in neonates without respiratory symptoms has not been established [3,21].


Fever Without Source or Unknown Origin Child. Bramson et al [43] combined their data with those of 2 prior studies [42,47] and subjected these to a statistical meta-analysis. The larger number of patients in the combined study allowed more valid conclusions concerning the accepted practice of performing chest radiographs in febrile infants as part of the sepsis workup. These 3 series had 671 infants. In 361 infants with no clinical evidence of pulmonary disease on history and physical examination, all had normal chest radiographs. A finding of only hyperinflation on a chest radiograph was interpreted as normal because it was felt that the infants would likely have a viral illness or reactive airway disease and would not usually be receiving antibiotics, unlike older children and adults [48]. Bramson et al [43] indicated that a chest radiograph in a patient with no pulmonary symptoms or signs would be positive <1.2% of the time. In the current era of S. pneumonia and H. flu vaccine use, this rate might fall even further. Murphy et al [49] found an incidence of radiographic pneumonia in 5.3% of 2,128 children under 10 years of age with no lower


Fever Without Source or Unknown Origin Child. respiratory symptoms (other than cough) and concluded that there was a low utility in obtaining chest radiographs in febrile children without cough. A longer duration of cough, fever, and leukocytosis increased the likelihood of radiographic pneumonia in these children.


Fever Without Source or Unknown Origin Child. The practice of routinely obtaining a chest radiograph has been challenged. Korones et al [61] evaluated 54 children with cancer who were hospitalized for hundreds of episodes of fever and neutropenia. They found an incidence of radiographic pneumonia of only 3% to 6%. The children without respiratory findings had no evidence of pneumonia on chest radiographs, and children who did not have chest radiographs showed no significant outcome differences from those who did. Philips et al [62] confirmed in a meta-analysis the low use of routine chest radiographs in this setting but stated that in those with a predisposition to pneumonia and those not responding to a short empiric course of antibiotics, chest radiographs should be performed despite the absence of clinical signs of a lower respiratory tract infection.


Fever Without Source or Unknown Origin Child. Children with neutropenia and FWS often undergo advanced imaging, but there is little evidence-based data about which studies are most efficacious. In their 2002 guidelines (not pediatric specific), the Infectious Diseases Society of America noted that one-half of febrile neutropenic patients with normal chest radiographs will have evidence of pneumonia on chest CT [63]. Archibald et al [36] evaluated the performance of CT in 83 neutropenic pediatric cancer patients who had 109 instances of fever lasting 4 days or more. Rates of positive CT findings varied by body region: head and neck, 8%; paranasal sinus, 41%; chest, 49%; and abdomen, 19%. Findings on paranasal sinus and chest CT led to changes in therapy in 24% and 30% of cases, respectively. However, they added that CT was rarely abnormal in the absence of localizing signs or symptoms and that in the absence of symptoms, CT findings rarely lead to therapeutic changes. In a more recent study, Agrawal et al [35] demonstrated a similar distribution of positive findings among body regions but found that only 2 of the initial positive CT scans led to a change in management (6.5% of positive scans, 0.8% of all initial scans). They therefore recommend limiting initial empiric CT imaging to the chest only in patients without localizing signs or symptoms. Regarding the use of FDG-PET/CT, Blokhuis et al [39] found a 78% sensitivity and 67% specificity in 12 of such children.


Fever Without Source or Unknown Origin Child. Variant 6: Infant or child more than 1 month of age with fever of unknown origin (FUO). Occult infection is the usual cause of FUO in children and is less commonly due to rheumatologic, autoimmune, neoplastic, or other inflammatory conditions [9,20,24,27,66,67]. Some children never have a specific diagnosis reached [9,24]. Evaluation of FUO in children is mainly based on thorough physical examination, history, and laboratory studies such as a complete blood cell count and peripheral smear, erythrocyte sedimentation rate, C- reactive protein, aerobic blood cultures, urinalysis, urine culture, tuberculin skin test, electrolytes, blood urea nitrogen, creatinine, hepatic enzymes, and human immunodeficiency virus serology [9,20,24,27,68,69]. Chest radiographs are usually obtained to evaluate for occult pneumonia and lymphadenopathy. Although many studies describe the clinical course of such patients, few of them examine the utility of diagnostic imaging modalities in these difficult patients. In general, if a detailed review of the history, physical examination, and screening evaluation fail to suggest a diagnosis, more extensive imaging can be considered. This includes abdominal ultrasound (US) and CT studies of the chest, abdomen, and paranasal sinus [4]. Steele et al [70] evaluated 109 children with FUO with conventional radionuclide techniques. These studies were often positive but rarely led to an unsuspected diagnosis.


Fever Without Source or Unknown Origin Child. FDG-PET/CT is sensitive in detection of infection, inflammatory diseases, vasculitis, arthritis, and malignancies and was found helpful on evaluation of FUO in several adult series [71,72] and meta-analysis studies [73,74]. The highest yield of FDG-PET can be expected in patients with adenopathy, low hemoglobin, and increased C- reactive protein levels [75]. There are only a few small series on the use of FDG-PET/CT in children with FUO [37]. Blokhuis et al [39] found a sensitivity of 80% and a specificity of 78% in 16 of such children. In the largest series to date by Jasper et al [38], FDG-PET/CT was used in evaluation of 44 children with FUO and 33 children with unexplained signs of inflammation without fever. According to the authors, the PET findings contributed to the final diagnosis in 35 patients (45%). The study methodology is limited, with no defined selection criteria for children with FUO in whom the PET study was performed and a vague definition on the benefits of FDG-PET/CT in reaching the final diagnosis.


Fever Without Source or Unknown Origin Child. Whole body magnetic resonance imaging (MRI) based on inversion recovery, T1, and diffusion sequences is an evolving technique that was used in several small series in the evaluation of systemic diseases, such as multifocal osteomyelitis and tumors, but there is not yet sufficient evidence for its use for evaluation of FUO [76-78]. The same applies to PET/MRI [79].


Fever Without Source or Unknown Origin Child. Summary of Recommendations Neonates younger than 1 month with FWS are a high-risk group; however, the yield of routine chest radiography is low in the absence of respiratory symptoms.


Fever Without Source or Unknown Origin Child. While there are references that report on studies with design limitations, 5 well designed or good quality studies provide good evidence.


Fever Without Source or Unknown Origin Child. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Imaging after Mastectomy and Breast Reconstruction. Introduction/Background Mastectomy may be performed to treat breast cancer [1] with some authors reporting increasing rates of mastectomy relative to breast conservation in the United States [2-4]. Mastectomy may also be performed as a prophylactic approach in women with a high lifetime risk of developing breast cancer. Mastectomy techniques have changed over time with radical mastectomy replaced by modified radical mastectomy and with options such as skin-sparing and nipple-sparing procedures now available [5]. In addition, mastectomies may be performed with or without reconstruction. Reconstruction approaches differ and may be autologous, involving a transfer of tissue (skin, subcutaneous fat, and muscle) from other parts of the body to the chest wall. Examples of autologous reconstruction include latissimus dorsi flaps, transverse rectus abdominis myocutaneous (TRAM) flaps, and variants such as deep inferior epigastric perforator flaps [1]. Reconstruction may also involve implants. Implant reconstruction may occur as a single procedure or as multistep procedures with initial use of an adjustable tissue expander allowing the mastectomy tissues to be stretched without compromising blood supply. Ultimately, a full-volume implant, which may be saline, silicone, or both, will be placed. Implant reconstruction often involves the placement of acellular matrix, which can increase risk of seroma formation and occasionally is visible on imaging.


Imaging after Mastectomy and Breast Reconstruction. Reconstructions with a combination of autologous and implant reconstruction may also be performed. Other techniques such as autologous fat grafting may be used to refine both implant and flap-based reconstruction [6].


Imaging after Mastectomy and Breast Reconstruction. Although most of the breast tissue is removed after mastectomy, recurrence may occur in residual tissue. The majority of recurrences in the reconstructed breast will be found in the skin and the subcutaneous tissues followed by recurrences deep to the pectoralis muscle [7]. Recurrence rates are reported to be approximately 1% to 2% annually for both mastectomy and mastectomy with reconstruction, and overall recurrence has been reported at between 2% to 15% and has been noted to vary based on the initial cancer type and stage as well as follow-up period of the study [5,7-13]. Clinical evaluation has been a mainstay of evaluation of the postmastectomy breast [4], and the appropriate surveillance imaging strategy for patients with a history of mastectomy with or without reconstruction is an evolving topic, with evidence predominantly drawn from small retrospective studies. Finally, women who have undergone mastectomy with or without reconstruction may present with symptomatic concerns, both in the immediate postoperative period and later. Sequalae of the surgery, such as hematomas, infections, and most commonly in the early postoperative period, fat necrosis [7], may present as palpable findings. Recurrent disease may also present as a palpable lump [7,14].


Imaging after Mastectomy and Breast Reconstruction. OR aNew York University School of Medicine, New York, New York. bPanel Chair, Alpert Medical School of Brown University, Providence, Rhode Island. cPanel Vice-Chair, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida. dUniversity of Louisville School of Medicine, Louisville, Kentucky; Society of Surgical Oncology. eUniversity of Cincinnati, Cincinnati, Ohio. fAlpert Medical School of Brown University, Providence, Rhode Island. gNorthwestern University Feinberg School of Medicine, Chicago, Illinois; American College of Physicians. hMemorial Sloan Kettering Cancer Center, New York, New York. iUniversity of Michigan, Ann Arbor, Michigan. jBeth Israel Deaconess Medical Center, Boston, Massachusetts. kStamford Hospital, Stamford, Connecticut; American College of Surgeons. lWomen and Infants Hospital, Providence, Rhode Island; American College of Obstetricians and Gynecologists. mRadiology Associates of Tallahassee, Tallahassee, Florida. nCentral Oregon Radiology Associates, Bend, Oregon. oSpecialty Chair, NYU Clinical Cancer Center, New York, New York.


Imaging after Mastectomy and Breast Reconstruction. 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.


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Imaging after Mastectomy and Breast Reconstruction. FDG-PET Breast Dedicated There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET breast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. Mammography Screening Annual screening with 2-D mammography or DBT is recommended for the contralateral native breast. There is insufficient evidence to support screening with 2-D mammography of the postmastectomy side. Although one small retrospective study has shown a small increase in cancer detection with mammography in postmastectomy patients [16], another study has demonstrated no benefit [8].


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI breast without intravenous (IV) contrast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast There is no relevant literature to support the use of MRI without and with IV contrast, specifically for screening the postmastectomy nonreconstructed breast. However, based on breast cancer risk, including factors such as age at cancer diagnosis, breast density, and family history, women with a personal history of cancer may undergo MRI for the contralateral native breast [17]. In this setting, the postmastectomy breast may be imaged and evaluated on MRI with potential for malignancy detection and characterization [18].


Imaging after Mastectomy and Breast Reconstruction. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi molecular breast imaging (MBI) for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. US Breast There is insufficient evidence to support the use of ultrasound (US) for screening in this setting. There is a paucity of evidence-based literature [16,18-20], with only a few small retrospective studies finding utility in screening with US in this setting. A subset of a retrospective study evaluated 67 women postmastectomy who had suspected recurrence and underwent US imaging; although some of these women were symptomatic, 7 recurrent impalpable cancers were detected only on US in the cohort [16]. This study also found 3/61 cancers detected only on mammography and not on US. A study of 1,796 US examinations in 874 asymptomatic patients (median follow-up of 37 months) found 15 clinically occult recurrences detected with US in 15 patients (cancer detection rate of 1.7% per patient and 0.8% per examination) [19]. Lee et al [20] evaluated 1,180 consecutive screening USs of the mastectomy site and the ipsilateral axillary fossa in 468 asymptomatic women and found 10 malignancies with a similar cancer detection rate of 2.1% per patient and 0.8% per screening examination.


Imaging after Mastectomy and Breast Reconstruction. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. Digital Breast Tomosynthesis Screening Although insufficient studies have been performed to assess the utility of DBT in this setting, multiple investigations have demonstrated that DBT is helpful in the screening setting of the native breast, thus decreasing recall rates and increasing cancer detection rates compared to a conventional mammographic workup [21-26].


Imaging after Mastectomy and Breast Reconstruction. Mammography Screening Evidence is limited, but a few retrospective studies suggest a benefit to screening women with autologous reconstruction after mastectomy for cancer in the reconstruction side. Helvie et al [27] looked at 214 consecutive screening mammograms in 113 women with TRAM flap reconstructions, 106 (94%) of which were performed after mastectomy for cancer. The cancer detection rate was 0.9% per screen and 1.9% per patient (2/106, 95% confidence interval [CI]: 0.33%, 7.32%) and positive predictive value (PPV) of biopsy was 33% (95% CI: 6%, 76%). Noroozian et al [10] in a larger study of 515 women and 618 mastectomies with reconstruction, 485 of which were performed for cancer, found the cancer detection rate of screening mammography to be 1.5/1,000 screening mammograms, comparable to that for one native breast of age-matched women. However, Freyvogel et al [28] retrospectively evaluated 541 postmastectomy and autologous reconstruction patients. Of these, 397 patients had screening mammography and 537 patients underwent routine clinical examination. Of the patients in the cohort, 26 of 27 (96.3%) had a clinically detectable recurrence, and the two cancers detected on screening were also palpable on follow-up clinical examination. Lee et al [29] evaluated 554 mammograms (265 TRAM flap reconstructions); no cancers were detected through screening and no interval nonpalpable recurrent breast cancers missed at mammography were identified, yielding a 0% rate of detection (exact 95% CI: 0.0%, 1.4%). The authors concluded that screening this population is less effective than screening average-risk women in their 40s, although it should be noted that the upper end of the CI is in line with the rates reported by the other studies mentioned above. Of note, there are no studies specifically evaluating decrease in mortality from screening women in this setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI of the breast without IV contrast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast There is insufficient evidence to support the use of MRI without and with IV contrast for screening in this setting. Based on breast cancer risk, including factors such as age at cancer diagnosis, breast density, and family history, women with a personal history of cancer may undergo MRI for the contralateral native breast [17]. In this setting, MRI will also allow for evaluation of the reconstructed breast and may be able to demonstrate recurrent malignancy, although the literature is scant with only several small studies and case reports [30,31]. Reiber et al [31], for example, used MRI to evaluate 41 patients with flap reconstructions, finding one mammographically and sonographically occult cancer in a patient with a latissimus dorsi flap. However, MRI also generated three false- positive biopsies.


Imaging after Mastectomy and Breast Reconstruction. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. US Breast There is no relevant literature to support the use of US for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. Imaging after Mastectomy and Breast Reconstruction


Imaging after Mastectomy and Breast Reconstruction. Digital Breast Tomosynthesis Screening There is no relevant literature to support the use of DBT for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. Mammography Screening There is no relevant literature to support the use of mammography for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast There is insufficient evidence to support the use of MRI without and with IV contrast for breast cancer screening in this setting.


Imaging after Mastectomy and Breast Reconstruction. Mammography Screening There is insufficient evidence to support the use of mammography for breast cancer screening in this population. A recent study by Noroozian et al [10] found no evidence to support the use of screening mammography in women who had undergone bilateral prophylactic mastectomy with autologous reconstruction. Of 133 prophylactic mastectomies with autologous reconstruction (805 mammograms), the cancer detection rate with mammography was 0%.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast Although there may be residual breast glandular tissue after mastectomy and MRI may be useful in delineating the amount of this residual tissue in women after prophylactic mastectomy [35], there is insufficient evidence to support the use of MRI breast without and with IV contrast for breast cancer screening in this population. A small retrospective study of breast MRI surveillance examinations performed in a subset of women who underwent bilateral mastectomy for either cancer or prophylaxis and had either implant, flap, or mixed reconstructions found no cancers that were not also evident on clinical examinations [33].


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast There is insufficient evidence to support screening for women with prophylactic mastectomy and implant reconstruction. It has been suggested that the yield of screening in this setting is especially low in the setting of retropectoral implant placement, in which recurrences are most likely to be clinically palpable [33,34]. A small retrospective study of breast MRI in 48 women status post bilateral mastectomy with and without reconstruction, some of whom underwent surveillance MRI, found no malignancy that was not also evident on clinical examination [33]. A retrospective study of 159 women status post bilateral mastectomy and reconstruction and undergoing MRI surveillance found no cancers in the subset of 31 women who had mastectomy performed for risk reduction [34].


Imaging after Mastectomy and Breast Reconstruction. Imaging after Mastectomy and Breast Reconstruction Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI for screening in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. Variant 7: Female. Palpable lump or clinically significant pain on the side of the mastectomy without reconstruction. Initial imaging. Digital Breast Tomosynthesis Diagnostic There is insufficient evidence to support the use of DBT as the initial imaging modality in women with palpable lumps or clinically significant pain on the side of the mastectomy. However, DBT can be useful in the diagnostic setting. It is known to improve lesion characterization in noncalcified lesions and to improve cancer detection when compared to conventional mammographic workup [36-38].


Imaging after Mastectomy and Breast Reconstruction. Mammography Diagnostic There is limited evidence to support the use of diagnostic mammography as the initial imaging modality in this clinical setting. A study of 67 women who underwent mastectomy and were suspected of recurrence found 3/61 cancers detected only on mammography and not on US [16]. Another study evaluating palpable lumps in 101 patients who had undergone mastectomy, the majority of whom (69%) had reconstruction with implants, demonstrated that mammography could be useful to confirm benign findings such as fat necrosis and benign calcifications identified on US [39]. However, diagnostic mammography yielded no additional cancers beyond those depicted on US.


Imaging after Mastectomy and Breast Reconstruction. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without IV Contrast There is no relevant literature to support the use of MRI without IV contrast in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast There is no evidence to support the use of MRI breast without and with IV contrast as the initial imaging modality in women with palpable lump or clinically significant pain on the mastectomy side. However, MRI may help characterize malignancy once identified and has been found to be more accurate than US in delineating extent of disease, although there is a paucity of evidence-based literature [18].


Imaging after Mastectomy and Breast Reconstruction. Sestamibi MBI There are a few small retrospective studies evaluating the use of Tc-99m sestamibi MBI in the context of a clinically suspicious lump. For example, Usmani et al [40] looked at 41 consecutive postmastectomy patients and found a sensitivity of 89%, specificity of 92%, PPV of 96%, negative predictive value (NPV) of 80%, and accuracy of 90% with Tc-99m sestamibi MBI. This was compared to US, which had a lower sensitivity of 86%, specificity of 77%, PPV of 89%, NPV of 71%, and accuracy of 83% (P = .001). The authors found that the combined sensitivity was 100%, specificity 77%, PPV 90%, NPV 100%, and accuracy 93%. However, there is insufficient evidence to support the use of Tc-99m sestamibi MBI as the initial imaging modality in this setting.


Imaging after Mastectomy and Breast Reconstruction. US Breast A retrospective evaluation of 118 palpable lumps in 101 patients, 9% of whom were status postmastectomy found 13 cancers in the mastectomy bed in women with a history of cancer. US had a high NPV of 97% and a PPV of 27% [39]. Gweon et al [41] evaluated both palpable and nonpalpable US BI-RADS categorization of lesions 4a and above at the mastectomy site and found 9/20 (45%) malignancies among palpable lesions; they also found that 100% of all BI-RADS 4c and BI-RADS 5 lesions proved to be malignant. In the event of an indeterminate US finding or an US finding suggestive of fat necrosis, diagnostic mammography or DBT may be helpful for lesion characterization and may preclude the need for biopsy if a clearly benign finding such as an oil cyst is identified.


Imaging after Mastectomy and Breast Reconstruction. Imaging after Mastectomy and Breast Reconstruction Digital Breast Tomosynthesis Diagnostic There is insufficient evidence to support the use of DBT as the initial imaging modality for women with palpable lumps or clinically significant pain on the side of the mastectomy with reconstruction. However, DBT can be useful in the diagnostic setting. It is known to improve lesion characterization in noncalcified lesions and to improve cancer detection when compared to conventional mammographic workup [36-38].


Imaging after Mastectomy and Breast Reconstruction. Mammography Diagnostic There is limited evidence to support the use of diagnostic mammography as the initial imaging modality in this clinical setting. Mammography may be helpful in identifying a benign postsurgical etiology of a palpable concern such as fat necrosis or oil cyst. For example, a study evaluating palpable lumps in 101 patients who had undergone mastectomy, the majority of whom (69%) had reconstruction with implants, demonstrated that mammography could be useful to confirm benign findings such as fat necrosis and benign calcifications identified on US [39]. However, the study also showed that diagnostic mammography yielded no additional cancers beyond those depicted on US. In another small study, Edeiken et al [42] found that mammography depicted only 14 of 25 (56%) of the recurrences visualized on US in women who had undergone autogenous myocutaneous flaps after mastectomy.


Imaging after Mastectomy and Breast Reconstruction. FDG-PET Breast Dedicated There is no relevant literature to support the use of FDG-PET breast as the initial imaging modality in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. MRI Breast Without and With IV Contrast There is insufficient evidence for MRI without and with IV contrast as the initial imaging modality in this setting. There are a few small studies evaluating MRI in women with symptomatic concerns and breast reconstruction. Devon et al [43] evaluated 24 TRAM reconstructions in 22 women with the majority of cases (64%) presenting with palpable abnormality or pain. Sixteen women in the study had MRI without mammography or US. In 4 of 24 cases (17%), MRI detected recurrent breast cancer, including axillary nodal recurrence. Of note, tissue expanders may be a contraindication to breast MRI [44].


Imaging after Mastectomy and Breast Reconstruction. Sestamibi MBI There is no relevant literature to support the use of Tc-99m sestamibi MBI as the initial imaging modality in this clinical setting.


Imaging after Mastectomy and Breast Reconstruction. US Breast There are a few small studies to support the use of US this setting. Dashevsky et al [39] looked at 118 palpable lumps in 101 patients postmastectomy (85% of whom were also postreconstruction). In total, 14 palpable lumps in 12 patients were malignant, and 104 palpable lumps in 89 patients were nonmalignant. Thirteen cancers were identified on US with only two false-positives (NPV 97%, PPV 27%). Edeiken et al [42] evaluated 20 women with autologous flap reconstruction after mastectomy who presented with palpable lumps; US ultimately identified 39 of 39 (100%) of cancers, 18 of which were palpable and 21 of which were occult. In the event of an indeterminate US finding, or an US finding suggestive of fat necrosis, diagnostic mammography or DBT may be helpful for lesion characterization and may preclude the need for biopsy if a clearly benign finding such as an oil cyst is identified.


Imaging after Mastectomy and Breast Reconstruction. Imaging after Mastectomy and Breast Reconstruction 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 Mastectomy and Breast Reconstruction. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Introduction/Background Hand injuries account for approximately 20% of emergency department visits [1]. According to the National Hospital Ambulatory Medical Care Survey, 1.5% of all emergency department visits involve hand and wrist fractures. Distal radius fractures are especially common, accounting for up to 18% of fractures in the elderly [2,3]. Because of increasing rates of osteoporosis, the incidence of distal radius fractures has been increasing [4]. Although most distal radius fractures in elderly patients are managed nonoperatively, the use of internal fixation is increasing. Internal fixation has a much higher cost than nonoperative treatment as well as increased rates of hospitalization [5].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. For most patients with trauma to the hand and wrist, conventional radiographs provide sufficient diagnostic information to guide the treating physician. However, delayed diagnosis is common because distal radius and scaphoid fractures may be radiographically occult [6]. When initial radiographs are normal but there is high clinical suspicion for fracture, further imaging with additional radiographic projections, CT, or MRI is appropriate. If associated soft-tissue injury is clinically suspected, CT, CT arthrography, MRI, MR arthrography, or ultrasound (US) may be indicated [7-10].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Successful treatment of distal radius fractures requires restoration of radial length, inclination, and tilt, as well as the realignment of the articular fracture fragments [9,11]. The presence of a coronally oriented fracture line, die- punch depression, or more than three articular fracture fragments are common indications for operative reduction [8]. Operative fixation resulting in <2 mm of residual articular surface step-off is usually considered necessary to avoid long-term complications, such as osteoarthritis [9,12].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. A standard 3-view radiographic examination of the hand shows most fractures and dislocations of the metacarpals and phalanges [13]. For phalangeal injuries, some centers include a PA examination of the entire hand, whereas others limit the examination to the injured finger. An internally rotated oblique projection, in addition to the standard externally rotated oblique, increases diagnostic yield for phalangeal fractures [15].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. 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.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Reprint requests to: publications@acr.org


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Most fractures of the thumb are visible on a 2-view radiographic examination, although there is a slight increase in diagnostic yield with the addition of an oblique projection [13], which can be obtained along with a PA examination of the whole hand.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT Area of Interest In patients with intra-articular fractures seen on radiography, CT shows articular fracture fragment displacement, depression, and comminution more accurately than conventional radiographs [7,9,10]. CT measurements of articular surface gap and step-off are more reproducible than radiographs [7]. The addition of 3-D surface- rendered reconstructions to the standard 2-D CT images has been shown to change operative management in up to 48% of intra-articular distal radius fractures [8].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. There is no evidence to support the use of CT with intravenous (IV) contrast in the setting of acute hand and wrist trauma.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Area of Interest MRI is not indicated initially in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US Area of Interest US is not indicated initially in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Bone Scan Area of Interest Bone scan is not indicated in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Variant 2: Suspect acute hand or wrist trauma. Initial radiographs negative or equivocal. Next imaging study. Radiography Area of Interest In patients with clinical suspicion of hand or wrist fracture and negative radiographs, one option is to place the patient in a short arm cast and repeat the radiographs at 10 to 14 days [13]. The downside of this option is that it results in delay of diagnosis, which may lead to functional impairment.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT Area of Interest When the initial radiographs are equivocal, CT without IV contrast is commonly used to exclude or confirm suspected wrist fractures [18]. CT shows intra-articular extension of distal radius fractures more frequently than radiography. Three-dimensional reconstructions can be particularly helpful in preoperative planning for complex articular injuries [7,8].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT should be used to exclude an occult fracture of the upper extremity. Unlike MRI, CT cannot evaluate for concomitant ligamentous injuries [19-21].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT is useful in diagnosing injuries that are difficult to recognize on radiographs, such as carpometacarpal joint fracture dislocations. For metacarpal and digital fractures, CT is usually not indicated during acute injury [22].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. There is no evidence to support the use of CT with IV contrast in the setting of acute hand and wrist trauma.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Area of Interest When initial radiographs are normal but there is high clinical suspicion for fracture, MRI without IV contrast can detect fractures of the distal radius and carpal bones [12,23-25]. One study of patients in which the radiographic findings did not explain the clinical symptoms reported that the MRI led to a change in diagnosis in 55% of patients and a change in patient management in 66% [12]. However, another study of patients with acutely injured wrists reported that the MRI did not predict the need for treatment better than the combination of physical examination and radiography [23]. More importantly, there was no difference in outcomes with MRI compared with radiography [24].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma Like CT, MRI shows intra-articular extension of distal radius fractures more frequently than radiography. Unlike CT, MRI shows concomitant ligament injuries, including tears of the scapholunate ligament, which may affect surgical treatment [26,27]. Despite these advantages, MRI performed immediately at the time of injury has little added value for determining which patients go on to surgery [23].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI is especially useful in evaluating hand soft-tissues injuries, including the collateral ligaments, volar plates, tendons, and pulleys. For metacarpal and digital fractures, MRI is usually not indicated during acute injury [22].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. There is no evidence to support the use of MRI with IV contrast in the setting of acute hand and wrist trauma.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US Area of Interest US may have a limited utility for evaluating bone injuries. Christiansen et al [28] reported 47% sensitivity and 61% specificity of US for the detection of scaphoid fractures. They concluded that US is not suitable for the early diagnosis of scaphoid fracture. In contrast, Hauger et al [29] reported that using cortical disruption as a diagnostic criterion on US is an accurate sign for detecting occult fractures of the scaphoid waist. Further study of US for the diagnosis of occult fractures is needed.


Acute Hand and Wrist Trauma


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT Arthrography Wrist When conventional radiographs do not show carpal malalignment, CT arthrography may be used to diagnose ligamentous tears, causing dynamic instability [32,33]. There is a growing body of literature comparing the diagnostic accuracy of MRI (at 1.5T or 3T), MR arthrography (indirect or direct at 1.5T or 3T), and CT arthrography. Overall, CT arthrography is reported to have the highest sensitivity, specificity, and accuracy.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. For the detection of scapholunate ligament tear, CT arthrography has sensitivity, specificity, and accuracy of nearly 100%. For the detection of lunotriquetral ligament tear, CT arthrography has approximately 100% sensitivity, 80% specificity, and 90% accuracy. Compared with arthroscopy, CT arthrography has 80% to 100% sensitivity for scapholunate and lunotriquetral ligament tears [33-35].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Compared to MR arthrography, CT arthrography detects partial ligament tears more accurately, detects articular cartilage defects more accurately, and has greater interobserver agreement [33]. Both CT arthrography and MR arthrography have a very high accuracy for diagnosing tears of the scapholunate ligament and lunotriquetral ligament; both are more accurate than conventional MRI [36].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. The accuracy of CT arthrography for extrinsic ligament injuries is unknown [37].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT Wrist CT is not indicated in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Wrist When conventional radiographs do not show carpal malalignment, MRI is commonly used to diagnose ligamentous tears. In the clinical setting of dynamic instability, MRI or MR arthrography may be performed. Modern MR techniques using 3T systems, dedicated wrist coils, and 3-D isovolumetric sequences offer fast imaging times with high spatial and contrast resolution [36,38].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. In general, 1.5T MRI has moderate sensitivity for the detection of scapholunate ligament tears and poor sensitivity for lunotriquetral ligament tears [35]. A meta-analysis of 11 studies reported sensitivities and specificities of 70% and 90% for detection of scapholunate ligament tears and 31% and 89% for detection of lunotriquetral ligament tears, respectively [39].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Sensitivity of 3T MRI is slightly better than 1.5T for the diagnosis of interosseous ligament tears. Reported sensitivities range from 65% to 89% for scapholunate ligament tears and 60% to 82% for lunotriquetral ligament


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma tears [36,40-42]. Some investigators consider the diagnostic accuracy of 3T MRI and MR arthrography to be comparable [38].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. The accuracy of MRI for extrinsic ligament assessment is unknown [37].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Extensor carpi ulnaris tendinopathy, tenosynovitis, and tendon rupture can be evaluated with MRI or US [43]. However, dynamic instability may be missed on MRI, unless sequences are performed in pronation and supination [44].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MR Arthrography Wrist At 1.5T, MR arthrography has greater sensitivity compared with conventional MRI [45,46]. Both MRI and MR arthrography have poor to moderate sensitivity for partial ligament tears [47,48]. When only complete tears are considered, MRI and MR arthrography may be equivalent [33].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. The accuracy of MR arthrography for extrinsic ligament assessment is unknown [37].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. For tears of the dorsal band of the scapholunate ligament, US sensitivity varies from 46% to 100% and specificity from 92% to 100% [50-52]. For the dorsal band of the lunotriquetral ligament, US sensitivity ranges from 25% to 50% and specificity from 90% to 100% [52,53]. US visualization of lunotriquetral ligament (particularly the structurally important volar band) is limited [49].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US can show dynamic subluxation of the extensor carpi ulnaris tendon during forced supination [44].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Bone Scan Wrist Bone scan is not indicated in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Variant 4: Initial radiographs showing distal radioulnar joint or carpal malalignment in the absence of fracture. Next imaging study. CT Wrist CT is the modality of choice for evaluating distal radioulnar joint stability [54]. The CT protocol should include imaging of both wrists in maximal pronation, neutral position, and maximal supination.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT examination with coronal, sagittal, and 3-D reformed images help demonstrate the extent of injury and help in treatment planning, particularly in cases of chronic perilunate dislocation [55].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. CT Arthrography Wrist Distal radioulnar joint instability and traumatic triangular fibrocartilage injuries can be evaluated with CT arthrography [56,57].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Wrist Distal radioulnar joint instability and traumatic triangular fibrocartilage injuries are usually associated with fluid in the distal radioulnar joint, which aids in the evaluation of the triangular fibrocartilage components on conventional MRI.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MR Arthrography Wrist MR arthrography increases the diagnostic accuracy for proximal lamina (foveal) triangular fibrocartilage tears [56,57].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US Wrist US is not indicated in this clinical setting.


Acute Hand and Wrist Trauma


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Variant 5: Acute hand fracture on radiographs. Suspect hand tendon or ligament trauma. Next imaging study. CT Hand CT has limited use for the diagnosis of soft-tissue injuries of the hand.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Hand MRI is ideal for evaluating tendon injuries and helping with surgical planning [58,59]. MRI is commonly used for the diagnosis of Stener lesions of the thumb [60] and the diagnosis of pulley system injuries [61].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Hergan et al [62] reported a 100% sensitivity and specificity for assessment of thumb ulnar collateral ligament tears. Spaeth et al [63] reported a sensitivity of 100% and specificity of 94% for detection of displaced ulnar collateral ligament tears in 16 cadaveric specimens.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US Hand A Stener lesion occurs when the aponeurosis of the adductor pollicis muscle becomes interposed between the ruptured ulnar collateral ligament of the thumb and its site of insertion at the base of the proximal phalanx. This lesion can be identified by absence of ulnar collateral ligament and the presence of a hypoechoic mass proximal to the apex of the metacarpal tubercle [64]. Dynamic examination shows the relationship of the aponeurosis to the retracted ligament stump [65].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US allows for diagnosis of pulley system injuries [66,67].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Bone Scan Hand Bone scan is not indicated in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Variant 6: Initial radiographs showing metacarpophalangeal, proximal interphalangeal, or distal interphalangeal joint malalignment in the absence of fracture. Next imaging study. CT Hand CT has limited use for the diagnosis of soft-tissue injuries of the fingers.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Hand MRI is ideal for evaluating tendon injuries and helping with surgical planning [58]. MRI may be used to assess capsule and collateral ligament injuries of the proximal interphalangeal and metacarpophalangeal joints [68].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI allows for the assessment of pulley system lesions [66,67]. MRI can accurately depict the pulley system, particularly the A2 and A4 pulleys, with lower sensitivity for A3 and A5 pulleys [70]. Hauger et al [70] reported direct identification of A2 and A4 pulleys in 12 of 12 cases (100%) and direct diagnosis of an abnormal A2 pulley in 100% and A4 pulley in 91% of 33 cases.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. For volar plate injuries, MRI may be used to diagnose tears that do not involve the underlying bone [71]. This is important because untreated lesions can result in contractures or joint laxity [72].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI is especially useful for detection of ulnar collateral ligament and radial collateral ligament injuries. Pfirrmann et al [74] reported a sensitivity of 67% and a specificity of 91% for collateral ligament injuries of the lesser metacarpophalangeal joints. With MR arthrography, sensitivity and specificity increased to 75% and 98%, respectively [74].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US Hand Dynamic US allows direct visualization of subluxation/dislocation of the extensor tendon while the patient flexes the metacarpophalangeal joint [16,75].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US helps evaluate injured flexor tendons and, in cases of completely lacerated tendons, helps identify the location of the proximal tendon stump [76].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma US allows for assessment of pulley system injuries [66,67], particularly the A2 and A4 pulleys, with lower sensitivity for A3 and A5 pulleys [70].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Variant 7: Suspect penetrating trauma with a foreign body in the soft tissues in the hand or wrist. Initial radiographs are negative. Next imaging study. CT Area of Interest CT has high sensitivity for detection of radiopaque foreign bodies [77,78]. In case of penetration of foreign body into deep tissues or bone, CT is recommended [79].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. There are no studies of the hand and wrist. For comparable studies regarding foreign bodies in the feet, CT has 63% sensitivity and 98% specificity. CT detection rates depend on the attenuation values of the foreign bodies. CT is superior to MRI in identifying water-rich fresh wood [80].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. MRI Area of Interest MRI has lower sensitivity compared to CT for detection of foreign bodies [78,79].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. For foreign bodies in the feet, MRI has 58% sensitivity and 100% specificity. MRI detection rates depend on the associated susceptibility artifact [80]. There are no comparable studies of the hand and wrist.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. In cases of suspected traumatic nerve injury of the hand and wrist, MRI with dedicated neurography sequences (eg, diffusion weighted) has shown improved visualization of the injured nerves [82].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US Area of Interest US is superior to radiography for detection of radiolucent foreign bodies and is recommended as the first choice when the foreign body is located within the superficial soft tissues with no bone around it [78,79,83].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. US allows for better localization of radiopaque foreign bodies, assessment of tendons and vascular structures, and US-guided removal of the foreign body [77].


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Bone Scan Area of Interest Bone scan is not indicated in this clinical setting.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma 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.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma

Acute Hand and Wrist Trauma. Acute Hand and Wrist Trauma


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Introduction/Background Chyle is primarily formed in the intestines and is composed of proteins, lipids, electrolytes, and lymphocytes. A chylous pleural effusion, or chylothorax, is a highly morbid condition defined by the presence of chyle within the pleural respiratory compromise, immunosuppression, malnutrition, and even death [1-3]. A review of the etiology, diagnosis, and management of chylothorax is presented in addition to an evaluation of relevant imaging studies.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Etiology Chylothoraces can be categorized etiologically as traumatic or nontraumatic. Collectively, the incidence of chylothorax is approximately 1 per 6000 admissions [1]. Historically, nontraumatic etiologies accounted for up to 72% of cases. Most recently, the largest study reports that traumatic etiologies account for 54% of cases [1,4-7]. The discrepancy may reflect the growth in thoracic oncologic resections or specific referral patterns.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Diagnosis Chylothorax most commonly presents with dyspnea, although chest pain, fever, and fatigue may also occur. Chyle is odorless, alkaline, sterile, and milky in appearance, although the appearance may vary based on the nutritional status of the patient. Increasing fatty intake increases the volume and can change the color of the fluid and has been described for the diagnosis of a chyle leak. The hallmark of chylous effusion is the presence of chylomicrons in the fluid. Objective diagnostic criteria include a pleural fluid triglyceride level >110 mg/dL and a ratio of pleural fluid to serum triglyceride level of >1.0. A ratio of pleural fluid to serum cholesterol level of <1.0 distinguishes chylothorax from cholesterol pleural effusions, which may present similarly [2,3].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Management The diagnosis is confirmed by draining the fluid for studies; this is also palliative. After replacing fluid and protein losses, a decision about conservative versus invasive therapies can be made. If the chylothorax reaccumulates, treatment is guided by daily outputs, with higher outputs warranting a more aggressive approach [2,4,8-11].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Conservative measures include management of the underlying disease, thoracentesis, and dietary modifications such as total parenteral nutrition or a nonfat diet to reduce production of chyle and consequently flow through the thoracic duct. Adjunctive therapy may include somatostatin, etilefrine, or nitric oxide, with the underlying etiology determining the efficacy, although the evidence remains scarce. The success of conservative therapy approaches 50% in nonmalignant etiologies but is only minimally beneficial in neoplastic etiologies [2,10,11].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Exact criteria for the implementation of invasive treatment are not well defined, but several authors advocate its use if conservative treatment has not resolved the chylothorax after 2 weeks, in higher-output chylothoraces, and in underlying neoplastic etiologies. Invasive treatments include surgical thoracic duct ligation, pleurodesis, and thoracic duct embolization (TDE) [2,4,8-11]. Less commonly, tunneled drains or pleural shunt procedures are performed, although prolonged drainage is not recommended as a long-term option because of increased risk of complications [12,13]. Although the technical success of direct surgical ligation is high, these debilitated patients


Chylothorax Treatment Planning

Chylothorax Treatment Planning. 1Principal Author and Panel Vice-Chair (Vascular Imaging), University of Michigan Health System, Ann Arbor, Michigan. 2Research Author, University of Michigan, Ann Arbor, Michigan. 3Panel Chair (Interventional Radiology), Cleveland Clinic Foundation, Cleveland, Ohio. 4Yuma Regional Medical Center, Yuma, Arizona. 5Massachusetts General Hospital, Boston, Massachusetts. 6Beth Israel Deaconess Medical Center, Boston, Massachusetts, Society of Thoracic Surgeons. 7Vanderbilt University Medical Center, Nashville, Tennessee, American College of Chest Physicians. 8University of Nebraska Medical Center, Omaha, Nebraska. 9University of California San Diego, San Diego, California. 10University of Texas Southwestern Medical Center, Dallas, Texas. 11Specialty Chair (Interventional Radiology), University of Chicago Hospital, Chicago, Illinois. 12Panel Chair (Vascular Imaging), UT Southwestern Medical Center, Dallas.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. 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.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Reprint requests to: publications@acr.org


Chylothorax Treatment Planning

Chylothorax Treatment Planning

Chylothorax Treatment Planning. Chylothorax Treatment Planning


Chylothorax Treatment Planning

Chylothorax Treatment Planning. are at increased risk for postoperative adhesions, infection, and poor wound healing. Reported postoperative mortality rates for patients who have failed conservative management range from 4.5% to as high as 50% [2,4,9,10].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. TDE is a percutaneous alternative to thoracic duct ligation. TDE allows for direct embolization (Type I) or needle disruption of the thoracic duct (Type II). Whereas the former directly treats the focus of injury, the latter is purported to create a controlled leak and inflammatory reaction in the retroperitoneum, which collateralizes and diverts flow from the thoracic duct. Over several successive publications, Cope et al [14,15] defined the technique and reported its feasibility. The initial series of 42 patients by Cope and Kaiser [16] revealed effective percutaneous treatment in >70% of cases. In 109 patients with traumatic thoracic duct leak, Itkin et al [5] reported 90% clinical resolution postembolization and 72% clinical resolution of the chyle leak with thoracic duct disruption. A subsequent report by Nadolski and Itkin [6] reported that TDE for nontraumatic chylous effusions in 34 patients was primarily successful if there was thoracic duct occlusion and extravasation. Pamarthi et al [7] reported 85% technical success and 64% clinical success in 105 patients with all-cause chylous leaks. Additional series have yielded similar results. Collectively, TDE has higher clinical success treating traumatic compared with nontraumatic chyle leaks and with TDE compared with thoracic duct disruption [8,9,11,17]. Overall, acute complications associated with TDE are minor and generally self-limited and are estimated at 2% to 6% [5-7]. Long-term complications may be seen in up to 14% of patients and may include leg swelling, abdominal swelling, or chronic diarrhea [18].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Overview of Imaging Modalities Different imaging studies serve different purposes in the evaluation and treatment of chylothorax.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Chest radiography Chest radiographs are routine examinations to evaluate dyspnea, particularly in postoperative scenarios and in patients who require intensive care. Radiographs can reliably detect pleural effusions or alternative diagnoses and monitor the position of support lines and tubes [19]. Although there is a high sensitivity for pleural effusions, this technique cannot reliably characterize the type of effusion.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Ultrasound Ultrasound (US) is sensitive for the detection of pleural fluid but cannot definitively discriminate between the types of pleural effusion [20]. US is now commonly used to help guide thoracentesis. Similarly, US can be used to facilitate intranodal lymphangiography, which is becoming a more accepted technique. Beyond facilitating these procedures, the role of US is limited with regard to the evaluation and management of chylothorax [21].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Conventional lymphangiography Lymphangiography has historically been used to opacify lymphatic vessels, detect lymph nodes and metastatic lesions, and evaluate lymphatic flow. Technological improvements in alternative diagnostic modalities led to an abandonment of this technique for oncologic purposes because it was technically challenging and time intensive, provided less information, and was more invasive. Although proficiency and training in the performance of lymphangiograms decreased, the utility of lymphangiography to demonstrate lymphatic leak became an established indication [8,9,14,22,23].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Traditionally, lymphangiography is performed from a pedal approach with the patient in a supine position. In this technique, a dye such as methylene blue that stains the lymphatics is injected into the web spaces between the toes. After the lymphatic vessel fills with the dye, the tissue overlying the lymphatic vessel is incised vertically, the lymphatic vessel is carefully skeletonized, and a 30-gauge lymphangiography needle is used to access the vessel. After securing the lymphatic access, 6 to 8 mL of ethiodized oil is instilled at a rate of 4 to 10 mL/h. Serial spot radiographs from the foot to the chest are acquired approximately every 10 to 15 minutes to follow the progression of the ethiodized oil as it ascends [22,24-27].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. More recently, an interest in nodal lymphangiography has developed [21,28]. In this alternative approach, an inguinal lymph node is targeted with a 25- to 26-gauge spinal needle under US guidance. The needle is positioned between the hilum and cortex of a lymph node. Hand injection of ethiodized oil at a rate of 1 mL per 5 to 7 minutes is then initiated for a total volume of 6 to 10 mL. Serial spot radiographs of the pelvis, abdomen, and thorax are then acquired to follow the progression of ethiodized oil [21,25,28-30]. Intranodal lymphangiography appears to decrease procedure time, is less technically challenging, and decreases the risk of wound infection when compared to pedal lymphangiography [21,28].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Chylothorax Treatment Planning Lymphangiography is able to define the site of the leak, diagnose alternative lymphatic vessel diseases, and prevent unnecessary procedures. Several authors have documented the therapeutic benefit of lymphangiography to occlude the site of leakage in 37% to 70% of patients without additional procedures [24-30]. Moreover, as detailed earlier, lymphangiography is intrinsic to the performance of TDE and guides the transabdominal access to the cisterna chyli and thoracic duct [14-16].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Magnetic resonance imaging chest and abdomen Visualization of the cisterna chyli, thoracic duct, and tributary lymphatic vessels with magnetic resonance imaging (MRI) was described in healthy volunteers as early as 1999 [34]. Initial MR lymphangiography technique involved unenhanced thin-collimated axial and coronal sequences similar to magnetic resonance cholangiopancreatography. Further refinements of sequences, particularly heavily T2-weighted sequences with and without and fat suppression, combined with 3-D techniques, maximum-intensity projections, and higher magnetic fields, increased the reliability and quality of MR lymphangiography [35-39]. Morphological features of the cisterna chyli and thoracic duct can be noted with identification of these structures in over 90% of preoperative patients, potentially providing valuable information and decreasing their risk of lymphatic leak [40- 43].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. The vast majority of studies are performed with unenhanced techniques, although delayed-phase cisterna chyli enhancement has been noted [44]. Respiratory gating and further technical refinements have the potential to better elucidate minor lymphatic vessels and lymphatic vessels in antidependent areas, which may not be seen through conventional lymphangiography. Recent studies are beginning to document the feasibility of using gadolinium- based contrast material injection within groin lymph nodes or in the web spaces between toes. Following the contrast material injection, patients are imaged with MRI. High image quality of lymph nodes, central lymphatics, and flow patterns within the lymphatics has been described, but these are preliminary research experiences and are not widely available [45,46].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Computed tomography chest and abdomen Older studies noted that noncontrast computed tomography (CT) visualizes the cisterna chyli in 1.7% of cases and could differentiate this from adjacent anatomy by its low attenuation, continuity with the thoracic duct, and tubular nature [47]. At least some portion of the thoracic duct was visualized in 55% of patients in a different series [48].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Although MRI more reliably visualized more segments of the thoracic duct than CT, the addition of CT increased the number of visualized segments [36]. More recent studies with 1-mm collimation and multiplanar reformation were able to identify the thoracic duct and cisterna chyli in nearly 100% of CT scans with normal anatomy [49]. Older reports using a combination of lymphangiography and CT did not find any additional value of CT in diagnosing the lymphatic injury, although in a more recent series, a combination of CT and unilateral pedal lymphangiography was able to identify the cause and locate the leak in 75% of idiopathic chylothoraces after failure of thoracic duct ligation [30]. Moreover, in this series of 24 patients, the lack of thoracic duct leakage was managed with nonoperative therapy with higher success rates [30]. No evidence is present to suggest a role for intravenous contrast material.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. When the underlying etiology of chylothorax is unknown or nontraumatic, the speed, sensitivity, and specificity of CT imaging can narrow the broader differential diagnosis.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Discussion of the Imaging Modalities by Variant Variant 1: Chylothorax treatment planning: traumatic etiology. Traumatic chylothoraces are a result of direct injury to thoracic lymphatics. Iatrogenic traumatic chylothorax complicates up to 4% of esophageal resections [1,2,4-7]. Lung cancer resections, cardiovascular surgeries, and


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Chylothorax Treatment Planning spinal surgeries can also be complicated by chylothorax, although at a lesser rate. Noniatrogenic causes of traumatic chylothorax include penetrating trauma, fracture-dislocation of the spine, and hyperflexion injuries [1,6,7]. Generally, the causative etiology is known in the traumatic setting. Sampling the pleural effusion confirms the diagnosis of chylothorax. Imaging a patient with a known traumatic chylothorax serves only to confirm the diagnosis and assist in therapeutic planning.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Chest radiography In the setting of a traumatic injury to the thoracic duct, most commonly postoperative or mechanical trauma, chest radiographs can confirm the presence of pleural fluid and lateralize the process and are routinely acquired in the daily evaluation of supportive lines and tubes [19].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Ultrasound US can be helpful in the guidance of thoracentesis and intranodal injection during lymphangiography [21]. Otherwise, US has little, if any, diagnostic role in the setting of a known traumatic chylothorax.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Conventional lymphangiography Conventional lymphangiography is the gold standard for visualization of lymph nodes, lymphatic vessels, cisterna chyli, the thoracic duct, and sites of injury [14,22,23]. Lymphangiography alone has been shown to be therapeutic in a small percentage of patients, irrespective of attempts at TDE or disruption [24-27]. When performed as a prelude to TDE, the combination is particularly effective in treating traumatic chylothorax, with technical and clinical success rates approaching 90% [5-9,11].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Nuclear lymphoscintigraphy Although nuclear lymphoscintigraphy may be able to confirm a lymphatic leak and identify the site, little evidence is present to support its routine use [31-33]. Moreover, this adds little to the clinical care of a patient as the traumatic etiology is usually known and any information gained would be redundant if conventional lymphangiography was performed as part of TDE.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Magnetic resonance imaging chest and abdomen The diagnostic benefit of MRI is negated in the setting of traumatic chylothoraces. However, the ability of MRI to map the lymphatic system can be of benefit in select cases where identifying the cisterna chyli and/or thoracic duct is difficult or conventional lymphangiography is unsuccessful [40-43].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Computed tomography chest and abdomen CT imaging is able to visualize portions of lymphatic system but provides less anatomic detail than MRI [36,47,48]. If the etiology is known, CT of the chest and abdomen, with or without intravenous contrast material, has little value in that it does not help guide therapy directed at chylothorax in most cases.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Variant 2: Chylothorax treatment planning: nontraumatic or unknown etiology. Nontraumatic chylothorax accounts for approximately 46% of chylothoraces and can be subcategorized as resulting from malignancy, as occurs in 18% of all chylothoraces, or nonmalignant etiologies, which account for 28% of all chylothoraces [1,2,6,7]. Of the malignant etiologies, lymphoma is the leading cause, accounting for 75% of all malignant chylothoraces. Nonmalignant, nontraumatic chylothorax has been described in lymphangioleiomyomatosis, sarcoidosis, cirrhosis, heart failure, nephrotic syndrome, venous thrombosis, filariasis, venolymphatic malformations, and a variety of other congenital, idiopathic, and systemic diseases. Approximately 9% of all chylous effusions are idiopathic [1,2,6,7]. Imaging a patient with either a nontraumatic chylothorax or a chylothorax of unknown etiology serves to narrow the differential diagnosis, further characterize the underlying cause and its severity, and assist in treatment planning.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Most patients with nontraumatic chylothoraces or chylothoraces of unknown etiologies present with acute respiratory illness (ARI), which consists of 1 or more of the following: cough, sputum production, chest pain, or dyspnea (with or without fever). The evaluation of ARI has been addressed by the American College of Radiology (ACR), and the imaging evaluation includes chest radiography and chest CT [50,51]. The consistent finding of chylothorax on initial imaging is the presence of a pleural effusion, which is a common medical problem with more than 50 recognized causes [52]. Pleural fluid studies are necessary for definitive diagnosis and to narrow the cause etiology of chylothorax.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Ultrasound US reliably detects pleural fluid but cannot definitively discriminate between the types of pleural effusion and provides minimal additional information to narrow the differential diagnosis [20]. US can be helpful in the guidance of thoracentesis and intranodal injection during lymphangiography [21].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Conventional lymphangiography Conventional lymphangiography is the gold standard for visualization of lymph nodes, lymphatic vessels, cisterna chyli, and the thoracic duct and for detection of lymphatic leakage [14,22,23]. In a nontraumatic or idiopathic chylothorax, conventional lymphangiography may help diagnose lymphatic vessel diseases and anatomic abnormalities and prevent unnecessary procedures. However, compared with traumatic chylothorax and particularly in the setting of a systemic disease, conventional lymphangiography does not always elucidate the underlying etiology. Additionally, TDE is less clinically effective in a nontraumatic chylothorax unless thoracic duct occlusion or extravasation is present [6].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Nuclear lymphoscintigraphy Nuclear lymphoscintigraphy has only a few reports that suggest it may be able to localize the site of chylous leak, particularly if used with 3-D single-photon emission CT/CT techniques [31-33]. Scintigraphic imaging alone provides limited localizing information and would not reliably narrow the differential diagnosis.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Magnetic resonance imaging chest and abdomen MRI accurately visualizes lymphatic structures without intravenous contrast material, depicting abnormal lymphatic malformations. With the addition of contrast material, MRI can characterize mediastinal masses, pleural-based lesions, and chest wall pathology. However, thoracic MRI has limited utility for parenchymal lung pathology [35-39].


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Chylothorax Treatment Planning Although there are references that report on studies with design limitations, 9 good-quality studies provide good evidence.


Chylothorax Treatment Planning

Chylothorax Treatment Planning. Supporting Documents For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Workup of Pleural Effusion or Pleural Disease. Introduction/Background Under normal circumstances, approximately 0.1 to 0.2 mL/kg body weight of pleural fluid resides in the pleural space [1]. Abnormal accumulation of pleural fluid is the most common clinical manifestation of pleural disease [2], typically caused by increased pulmonary capillary pressure, increased pleural membrane permeability, decreased oncotic pressure, or lymphatic obstruction [3]. Pleural effusions are categorized as transudative or exudative [4], with transudative effusions usually reflecting the sequala of a systemic etiology and exudative effusions usually resulting from a process localized to the pleura [5]. Common causes of transudative pleural effusions include congestive heart failure, cirrhosis, and renal failure, whereas exudative effusions are typically due to infection, malignancy, or autoimmune disorders [6], emphasizing the importance of prompt diagnosis to aid in patient management [7]. In general, physical examination findings have a lower positive likelihood ratio for detection of pleural effusions [8], supporting the use of imaging to aid in identification of clinically significant pleural effusions.


Workup of Pleural Effusion or Pleural Disease. When imaging pleural effusions, chest radiographs can typically detect >75 mL on the lateral view and >175 mL on the frontal view [9]. Thoracic ultrasound (US) can detect >20 mL of pleural fluid [10]. Chest CT can detect >10 mL of pleural fluid, and is considered the reference standard for imaging [11].


Workup of Pleural Effusion or Pleural Disease. 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.


Workup of Pleural Effusion or Pleural Disease. OR The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization.


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Workup of Pleural Effusion or Pleural Disease. Workup of Pleural Effusion or Pleural Disease Discussion of Procedures by Variant Variant 1: Recent pneumonia with suspected parapneumonic effusion or empyema. Initial imaging. CT Chest With IV Contrast Current American Association for Thoracic Surgery consensus guidelines recommend CT chest with intravenous (IV) contrast in cases of suspected parapneumonic effusion (class IIa) [13]. A recent meta-analysis reported 5 chest CT findings most commonly associated with the diagnosis of empyema: pleural enhancement (sensitivity 84%, 95% confidence interval [CI], 62%-94%; specificity 83%, 95% CI, 75%-89%), pleural thickening (sensitivity 68%, 95% CI, 56%-77%; specificity 87%, 95% CI, 80%-92%), loculation (sensitivity 52%, 95% CI, 44%-59%; specificity 89%; 95% CI, 82%-94%), extrapleural fat proliferation (sensitivity 53%, 95% CI, 47%-60%; specificity 91%, 95% CI, 82%-96%), and increased attenuation of the extrapleural fat (sensitivity 39%, 95% CI, 32%-48%; specificity 97%, 95% CI, 94%-98%) [14]. Of note, these pooled sensitivities and specificities include CT chest with IV contrast or CT chest without IV contrast. Pleural enhancement has the highest area under curve for the diagnosis of empyema (0.86) and for distinguishing between simple parapneumonic effusion and empyema (0.83) [14]. In a secondary analysis of the Multi-centre Intra-pleural Sepsis Trial (MIST) 2 trial of patients with laboratory proven pleural infection, the combination of parietal pleural enhancement and pleural thickening was seen in 98.7% of patients (95% CI, 92.8%-99.8%) on pleural-phase contrast-enhanced CT [15]. The presence of pleural enhancement with pleural gas/microbubbles [16] or larger pleural effusion size [17] also boosts the accuracy for identifying parapneumonic effusions requiring thoracentesis [16,17]. Parapneumonic effusions <2.5 cm in anteroposterior (AP) dimension can often be managed without thoracentesis [18]. From a technical perspective, acquiring the CT scan 60 seconds after the IV contrast bolus optimizes visualization of the pleura [19,20].


Workup of Pleural Effusion or Pleural Disease. CT Chest Without and With IV Contrast There is no relevant literature to support the use of CT chest without and with IV contrast in the initial imaging of recent pneumonia with suspected parapneumonic effusion or empyema.