Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. FDG-PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of FDG-PET/CT in this clinical scenario.


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. DOTATATE PET/CT Skull Base to Mid-Thigh There is no relevant literature to support the use of Ga-68-DOTATATE PET/CT in this clinical scenario.


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. Octreotide Scan with SPECT or SPECT/CT Chest and Abdomen There is no relevant literature to support the use of In-111 somatostatin receptor scan with SPECT or SPECT/CT in this clinical scenario.


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. There is no relevant literature that has assessed the performance of MRI without IV contrast specifically for this clinical scenario. Therefore, the committee recommendations on the use of MRI without IV contrast are based primarily on expert opinion.


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. RBC Scan Abdomen and Pelvis There is no relevant literature to support the use of a Tc-99m RBC scan in this clinical scenario.


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. Liver Spleen Scan There is no relevant literature to support the use of a Tc-99m sulfur colloid scan in this clinical scenario.


Liver Lesion Initial Characterization

Liver Lesion-Initial Characterization

Liver Lesion Initial Characterization. Liver Lesion-Initial Characterization


Liver Lesion Initial Characterization

Liver Lesion-Initial Characterization


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. 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.


Liver Lesion Initial Characterization

Liver Lesion Initial Characterization. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Urinary Tract Infection Child

Urinary Tract Infection Child. Cystitis is a UTI limited to the bladder. Cystitis typically presents with localized symptoms of frequency, urgency, fever, and dysuria. Cystitis in the absence of pyelonephritis is usually not associated with long-term sequelae [4]. Acute pyelonephritis is infection of one or both kidneys. Pyelonephritis typically presents with systemic symptoms such as high fever, malaise, vomiting, abdominal or flank pain, and tenderness [2-5]. Pyelonephritis is diagnosed in children on the basis of the presence of pyuria and/or bacteriuria, fever, flank pain, or tenderness. Between 50% and 64% of children who have a febrile UTI are found to have defects on renal cortical scintigraphy indicating acute pyelonephritis [7]. Pyelonephritis can cause renal scarring, which is the most severe long-term sequela of UTI and can lead to accelerated nephrosclerosis, leading to hypertension and chronic renal failure [2-5]. The reported incidence of scarring in children after pyelonephritis varies widely in the literature. A systematic review showed that 15% (95% confidence interval, 11%-18%) of children had evidence of renal scarring after the first episode of UTI [7]. With the increased use of prenatal ultrasound (US), it was determined that many of the scars that had been attributed to pyelonephritis actually occur in utero and represent renal dysplasia [2-5]. Contrary to earlier studies suggesting that renal scarring secondary to pyelonephritis is the most common cause of chronic renal disease in children, it is now evident that the long-term risk is low [2-5]. The role of imaging is to guide treatment by identifying patients who are at high risk to develop recurrent UTIs or renal scarring. However, identification of children at risk is relevant only if there is effective treatment. Current management strategy to prevent UTIs and renal scarring is based on prophylactic antibiotics and selective surgical correction of vesicoureteral reflux (VUR).


Urinary Tract Infection Child

Urinary Tract Infection Child. UTI in a neonate or young infant requires special consideration. The prevalence of UTI in term neonates and young infants varies from 0.1% to 1%, with a predominance in the first 2 months of life in neonates and young infants AMAB [8-11]. The presentation of UTI is generally nonspecific, with symptoms similar to neonatal sepsis, and not all children will have fever. Concomitant bacteremia is common with UTI and was observed ranging from 4% to 36.4% [5,8-11]. Neonates with UTI have a high incidence of urinary anomalies; the most common is VUR [8,10- 12].


Urinary Tract Infection Child

Urinary Tract Infection Child. Reprint requests to: publications@acr.org


Urinary Tract Infection Child

Urinary Tract Infection-Child

Urinary Tract Infection Child. Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. tract UTI, or 1 episode of UTI with acute pyelonephritis/upper tract UTI plus 1 or more episodes of UTI with cystitis/lower tract UTI, or 3 or more episodes of UTI with cystitis/lower tract UTI [13]. Upper tract refers to the kidneys and ureters, and lower tract is distal to the ureters.


Urinary Tract Infection Child

Urinary Tract Infection Child. Special Imaging Considerations Voiding urosonography (VUS) is a safe and accurate method to evaluate for VUR. The bladder is filled with a solution containing microbubbles that appear echogenic by US.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT urography (CTU) is an imaging study that is tailored to improve visualization of both the upper and lower urinary tracts. There is variability in the specific parameters, but it usually involves unenhanced images followed by intravenous (IV) contrast-enhanced images, including nephrographic and excretory phases acquired at least 5 minutes after contrast injection. Alternatively, a split-bolus technique uses an initial loading dose of IV contrast and then obtains a combined nephrographic-excretory phase after a second IV contrast dose; some sites include arterial phase. CTU should use thin-slice acquisition. Reconstruction methods commonly include maximum intensity projection or 3-D volume rendering. For the purposes of this document, we make a distinction between CTU and CT abdomen and pelvis without and with IV contrast. CT abdomen and pelvis without and with IV contrast is defined as any protocol not specifically tailored for evaluation of the upper and lower urinary tracts and without both the nonenhanced and excretory phases.


Urinary Tract Infection Child

Urinary Tract Infection Child. MR urography (MRU) is also tailored to improve imaging of the urinary system. Unenhanced MRU relies upon heavily T2-weighted imaging of the intrinsic high signal intensity from urine for evaluation of the urinary tract. IV contrast is administered to provide additional information regarding obstruction, urothelial thickening, focal lesions, and stones. A contrast-enhanced T1-weighted series should include corticomedullary, nephrographic, and excretory phase. Thin-slice acquisition and multiplanar imaging should be obtained. For the purposes of this document, we make a distinction between MRU and MRI abdomen and pelvis without and with IV contrast. MRI abdomen and pelvis without and with IV contrast is defined as any protocol not specifically tailored for evaluation of the upper and lower urinary tracts, without both the precontrast and excretory phases, and without heavily T2-weighted images of the urinary tract.


Urinary Tract Infection Child

Urinary Tract Infection Child. OR Discussion of Procedures by Variant Variant 1: Child assigned male at birth (AMAB). Younger than 2 months of age. First febrile urinary tract infection with appropriate response to medical management. Initial imaging. CT Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis with IV contrast in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without IV contrast in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CTU Without and With IV Contrast There is no relevant literature to support the use of CTU in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. DMSA Renal Scan A Tc-99m dimercaptosuccinic acid (DMSA) scan can be done for the initial imaging, close to the time of febrile UTI to evaluate for the presence of pyelonephritis. If the DMSA scan is normal, voiding cystourethrography (VCUG) may be avoided in >50% of individuals [14]. Tc-99m DMSA has a good image quality and is a desirable agent for renal cortical scintigraphy, especially in small infants, in patients with poorly functioning kidneys, and when other studies have identified dilated uropathy or high-grade VUR [15]. The UK National Institute for Health and Care Excellence (NICE) guidelines do not recommend DMSA for infants <6 months of age with first febrile UTI who respond well to treatment within 48 hours [16].


Urinary Tract Infection Child

Urinary Tract Infection Child. Fluoroscopy Voiding Cystourethrography Literature on VCUG has mixed recommendations. Fluoroscopic VCUG has been shown to detect VUR in newborn children AMAB even if US is normal [8-11]. A finding of VUR, especially high-grade VUR, may lead to a change in management [9]. VUR is more commonly detected in children AMAB compared with children AFAB [17]. In addition, one of the primary concerns in young infants AMAB is diagnosing posterior urethral valves [9]. The NICE guidelines do not recommend VCUG for infants AMAB <6 months of age with first febrile UTI who respond well to treatment within 48 hours. If there is poor urine flow or if there is a family history of VUR, VCUG may be helpful if there is an abnormal kidney US study [16]. Others advocate performing routine VCUG studies in all newborns AMAB [9]. Furthermore, recent data have shown that in children <3 months of age with first febrile UTI, the presence of E coli in urine, and normal renal and bladder US, VCUG can be safely avoided [18].


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis with IV contrast in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRU Without and With IV Contrast There is no relevant literature to support the use of MRU in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. Nuclear Medicine Cystography There is no relevant literature to support the use of nuclear medicine cystography in the evaluation of a child AMAB <2 months of age for the initial imaging of a first febrile UTI. There is good correlation between nuclear medicine cystography and VCUG for the detection of reflux [19]. The nuclear cystogram does not allow for urethral assessment in a infant AMAB [20].


Urinary Tract Infection Child

Urinary Tract Infection Child. US Kidneys and Bladder In a child AMAB <2 months of age, there is increased incidence of sepsis and renal anomalies associated with UTIs and increased rate of hospitalization. Therefore, the potential benefit of imaging in children <2 months of age is greater than in older children. However, there is less convincing evidence for the benefit of imaging based on outcome [8-11,21]. Hydronephrosis is the most frequent abnormality, found in 45% of neonates with UTI [9]. Postnatal US prior to 2 months of age is typically performed even if the prenatal US was normal. The NICE guidelines for UTI recommend US in evaluation of UTI in children <6 months of age within 6 weeks of the UTI if typical infection or during the acute infection if an atypical infection [16]. In the study by Goldman et al [9] on newborn AMAB with UTI, 8 of 12 children with abnormal postnatal US had a normal intrauterine US; 1 patient had posterior urethral valves, and 4 patients had grades III and IV VUR. The main limitations of US are the detection of pyelonephritis, scarring, and VUR. In a study by Chang et al [22] for evaluation of young infants (<3 months of age) with bacteremic UTI, US kidneys and bladder and fluoroscopic VCUG abnormalities were common, and the authors did not refer to any special imaging considerations for bacteremia in imaging decisions for otherwise well- appearing young infants with UTI. US has a high specificity (97.2%) for the detection of findings suggestive of VUR in children after the first UTI [23]. Sensitivity of US for the detection of findings suggestive of high-grade VUR is markedly improved when uroepithelial thickening is considered [24]. The main limitation of US is the low sensitivity (76.5%) for detecting VUR and renal scarring [25-31].


Urinary Tract Infection Child

Urinary Tract Infection Child. Voiding Urosonography VUS is an alternative to VCUG for the evaluation of VUR in children, with a comparable sensitivity and specificity ranging from 80% to 100% and 77.5% to 98%, respectively [32-39]. The diagnostic accuracy of VUS compared


Urinary Tract Infection Child

Urinary Tract Infection Child. Variant 2: Child assigned female at birth (AFAB). First febrile urinary tract infection with appropriate response to medical management. Initial imaging. CT Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis with IV contrast in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without IV contrast in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CTU Without and With IV Contrast There is no relevant literature to support the use of CTU in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. DMSA Renal Scan A Tc-99m DMSA scan can be done for initial imaging, close to the time of febrile UTI, to evaluate for the presence of pyelonephritis. This top-down approach has been suggested in literature. If the DMSA scan is normal, VCUG may be avoided in more than 50% of individuals [14]. Tc-99m DMSA has a good image quality and is a desirable agent for renal cortical scintigraphy, especially in small infants, in patients with poorly functioning kidneys, and when other studies have identified dilated uropathy or high-grade VUR [15]. The NICE guidelines do not recommend DMSA for infants <6 months of age with first febrile UTI who respond well to treatment within 48 hours, but they do recommend DMSA for atypical or recurrent UTI [16].


Urinary Tract Infection Child

Urinary Tract Infection Child. Fluoroscopy Voiding Cystourethrography A finding of VUR, especially high-grade VUR, may lead to a change in management [9]. The NICE guidelines do not recommend VCUG for infants AFAB <6 months of age with first febrile UTI who respond well to treatment within 48 hours. Furthermore, recent data has shown that in children <3 months of age with first febrile UTI, the presence of E coli in urine, and normal renal and bladder US, VCUG can be safely avoided [18]. In patients AFAB, there is usually less of a need for detailed anatomic evaluation of the urethra, and radionuclide cystography can be performed as an alternative to VCUG [42]. However, fluoroscopic VCUG may still be a useful study to perform based on consensus opinion derived from common practice.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis with IV contrast in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRU Without and With IV Contrast There is no relevant literature to support the use of MRU in the evaluation of a child AFAB <2 months of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. Nuclear Medicine Cystography There is good correlation between nuclear medicine cystography and VCUG for the detection of reflux [19]. For more information, please see the fluoroscopic VCUG section. In patients AFAB, there is usually less of a need for detailed anatomic evaluation of the urethra, and radionuclide cystography can be performed instead of VCUG [42].


Urinary Tract Infection Child

Urinary Tract Infection-Child

Urinary Tract Infection Child. Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. The literature in this patient population is evolving with a focus on other modalities such as VUS and fluoroscopy VCUG. It should be noted that the primary evidence supporting use of nuclear cystography is generally older than that of other modalities.


Urinary Tract Infection Child

Urinary Tract Infection Child. US Kidneys and Bladder In patients AFAB <2 months of age, there is an increased incidence of sepsis and renal anomalies associated with UTIs and an increased rate of hospitalization. Therefore, the potential benefit in children <2 months of age is greater than in older children. However, there is less convincing evidence for the benefit of imaging based on outcome [8- 11,21]. Hydronephrosis is the most frequent abnormality, found in 45% of neonates with UTI [9]. Postnatal US prior to 2 months of age is typically performed even if the prenatal US was normal. The NICE guidelines for UTI recommend US in evaluation of UTI in children <6 months of age within 6 weeks of the UTI if typical infection or during the acute infection if an atypical infection [16]. As discussed earlier, the main limitations of US are the detection of pyelonephritis, scarring, and VUR. In a study by Chang et al [22] for evaluation of young infants (<3 months of age) with bacteremic UTI, US kidneys and bladder and fluoroscopic VCUG abnormalities were common, and the authors did not refer to any special imaging considerations for bacteremia in imaging decisions for otherwise well-appearing young infants with UTI. Sensitivity of US for the detection of high-grade VUR is markedly improved when uroepithelial thickening is considered [24]. The main limitation of US is the low sensitivity (76.5%) for detecting VUR and renal scarring [25-31].


Urinary Tract Infection Child

Urinary Tract Infection Child. Variant 3: Child. 2 months to 6 years of age. First febrile urinary tract infection with appropriate response to medical management. Initial imaging. Prospective studies in children between the ages of 2 months and 6 years with UTIs were done to evaluate the effect of therapy [6,43,44]. There is limited evidence to support routine imaging of uncomplicated UTIs, and optimal imaging is controversial [2,5,43,45]. Currently there are 2 main methods for evaluating children with UTIs: the bottom-up approach [2], which focuses on detection of VUR, and the top-down approach [2,5,16], which focuses on the diagnosis of acute pyelonephritis and renal scarring [2,5]. DMSA followed by cystourethrography if DMSA renal scan suggests pyelonephritis is the top-down approach. The potential benefit of this approach is a decrease in the number of cystourethrography studies.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis with IV contrast in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without IV contrast in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. CTU Without and With IV Contrast There is no relevant literature to support the use of CTU in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. DMSA Renal Scan Tc-99m DMSA is a sensitive (90%) and specific (95%) test for detecting pyelonephritis [46]. The NICE guidelines do not suggest DMSA renal scan if the patient responds well to treatment within 48 hours. A delayed DMSA renal scan (4-6 months) to evaluate for renal scarring in high-risk patients with atypical or recurrent UTI is recommended


Urinary Tract Infection Child

Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. [16]. Evidence of acute pyelonephritis is detected by DMSA in children with UTIs in approximately 50% to 80% of cases [47-52]. However, short-term studies have demonstrated that many of these abnormalities resolve over time, irrespective of whether a prophylactic antibiotic was used [53-55]. This suggests little benefit in using renal cortical scintigraphy after the first episode of UTI [5]. Furthermore, the high incidence of pyelonephritis identified on DMSA suggests that performing DMSA will not change the need to perform VCUG in many patients. There is conflicting evidence on the sensitivity of renal cortical scintigraphy and the top-down approach in the detection of sequela of VUR [45,56,57]. In a randomized controlled study comparing oral versus IV antibiotic administration, 308 patients who had Tc-99m DMSA were evaluated. The sensitivity of this top-down approach for VUR detection was 70%, with specificity of 42% [45]. A meta-analysis on the use of DMSA in acute UTI yielded a sensitivity and specificity of 79% and 53%, respectively, for grades 3 to 5 VUR. There was marked statistical heterogeneity between the studies. The authors concluded that acute-phase DMSA renal scanning is not useful as a replacement for VCUG in the evaluation of young children with a first febrile UTI [56].


Urinary Tract Infection Child

Urinary Tract Infection Child. Fluoroscopy Voiding Cystourethrography The Randomized Intervention for Children With Vesicoureteral Reflux study, which enrolled 607 children, 2 months to 6 years of age with any grade of VUR, demonstrated that 2 years of prophylactic antibiotics in children with VUR decreased the incidence of recurrent UTIs by half (number needed to treat for 2 years was 8) [58]. Patients with high-grade VUR (grades III and IV) are more likely to have recurrent UTIs and scarring [7,43,50,58-61] and may benefit even more from prophylactic antibiotics. The Swedish study randomly assigned 203 children, 12 to 23 months of age, with dilated (grade III or IV) VUR and demonstrated benefit only in patients AFAB who received either prophylactic antibiotics or endoscopic treatment in decreasing recurrent UTI (number needed to treat for 2 years, 2.5 and 3, respectively) [62]. Patients AFAB who received antimicrobial prophylaxis had the lowest incidence of renal scarring (number needed to treat for 2 years was 5) [62].


Urinary Tract Infection Child

Urinary Tract Infection Child. The NICE guidelines do not recommend VCUG for patients from 6 months to 3 years of age with first febrile UTI who respond well to treatment within 48 hours and have a normal renal and bladder US study, normal urine flow, and no family history of VUR. However, VCUG is recommended for patients with a family history of VUR [16]. The NICE guidelines do not recommend VCUG for patients >3 years of age with first febrile UTI. The AAP guidelines suggest that VCUG should not be performed routinely after the first febrile UTI for patients 2 to 24 months of age but that VCUG is indicated if the renal and bladder US reveals hydronephrosis, scarring, or other findings that would suggest either high-grade VUR or obstructive uropathy. Furthermore, VCUG may be indicated in other atypical or complex clinical circumstances [41].


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis with IV contrast in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRU Without and With IV Contrast There is no relevant literature to support the use of MRU in the evaluation of a child 2 months to 6 years of age for the initial imaging of a first febrile UTI.


Urinary Tract Infection Child

Urinary Tract Infection Child. Nuclear Medicine Cystography Good correlation has been shown between nuclear medicine cystography and VCUG for the detection of VUR [19]. Unlike in children AMAB, detailed urethral assessment in children AFAB is less necessary, so radionuclide cystography can be performed as an alternative for VCUG in patients AFAB [42,48]. A finding of VUR, especially high-grade VUR, may lead to a change in management [9]. Nuclear medicine cystography may reveal VUR despite a normal VCUG in children with recurrent febrile UTI [63]. For more information, please see the fluoroscopic VCUG section.


Urinary Tract Infection Child

Urinary Tract Infection Child. US Kidneys and Bladder The main benefit of US is for the detection of underlying congenital renal anomalies [1,16]. The potential harm of using US as the only imaging for UTI is the poor sensitivity for VUR and pyelonephritis/scarring [25-30,64]. There are limited data showing inconsistent results on the sensitivity of US in the detection of dilated VUR [65,66]. Grayscale US identifies approximately 25% of the patients with acute pyelonephritis and approximately 40% of the patients with chronic parenchymal scarring [29,31,67-72].


Urinary Tract Infection Child

Urinary Tract Infection-Child

Urinary Tract Infection Child. Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. In a retrospective study of 2,259 children <5 years of age, sensitivity of US was related to criteria for the definition of a normal study. With the use of the most relaxed criteria (25% abnormal), US had a sensitivity of 28% (specificity of 77%), and with the most stringent criteria (4% abnormal), US had a sensitivity of 5% (specificity of 97%) [31]. Assuming a 40% prevalence of VUR and a 20% recurrent rate of UTIs in 100 children who have US, up to 11 children will have positive US studies that will be followed by a VCUG study, of which 8 will be positive for VUR. Two years of a prophylactic antibiotic will decrease recurrent UTIs from up to 2 children to 1 child. This means that 1 child will benefit from US and an additional 3 children that may benefit from prophylactic antibiotic will not be treated. In addition, with the increased use of prenatal US screening, the yield of detection of unknown renal abnormalities in children with UTIs has decreased [73].


Urinary Tract Infection Child

Urinary Tract Infection Child. A few studies with small series of children suggest good correlation between power Doppler and Tc-99m DMSA for pyelonephritis [74,75]. Other studies, however, demonstrated low sensitivity for pyelonephritis and low prediction for development of renal scarring [49,76,77]. Therefore, the use of power Doppler as a replacement for DMSA is not useful [26,49,76].


Urinary Tract Infection Child

Urinary Tract Infection Child. The NICE guidelines for UTI do not recommend US in evaluation of UTI in children >6 months of age if typical infection [16]. The AAP guidelines recommend US for children with a febrile UTI from ages 2 to 24 months [41].


Urinary Tract Infection Child

Urinary Tract Infection Child. Variant 4: Child. Older than 6 years of age. First febrile urinary tract infection with appropriate response to medical management. Initial imaging. The incidence of new-onset UTI in children >6 years of age is low and often associated with behavioral abnormalities, dysfunctional elimination syndrome, or initiation of sexual intercourse in adolescents [78,79]. Patients AFAB are affected more often than patients AMAB [78]. The likelihood of detection of a previously unknown underlying renal anomaly is low [79]. There is no evidence to support any routine imaging in the first UTI in this group of patients.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis with IV contrast in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without IV contrast in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. CTU Without and With IV Contrast There is no relevant literature to support the use of CTU in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. DMSA Renal Scan The NICE guidelines do not recommend DMSA renal scan for patients >6 years of age with first febrile UTI [16].


Urinary Tract Infection Child

Urinary Tract Infection Child. Fluoroscopy Voiding Cystourethrography The NICE guidelines do not recommend VCUG for patients >6 years of age with first febrile UTI [16].


Urinary Tract Infection Child

Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis with IV contrast in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRU Without and With IV Contrast There is no relevant literature to support the use of MRU in the evaluation of a child >6 years of age for the initial imaging of a first febrile UTI with appropriate response to medical management.


Urinary Tract Infection Child

Urinary Tract Infection Child. Nuclear Medicine Cystography The NICE guidelines do not recommend cystography for patients >6 years of age with first febrile UTI [16].


Urinary Tract Infection Child

Urinary Tract Infection Child. Voiding Urosonography The NICE guidelines do not recommend VUS for patients >6 years of age with first febrile UTI [16]. However, VUS may be a useful study to perform based on consensus opinion.


Urinary Tract Infection Child

Urinary Tract Infection Child. Variant 5: Child. Atypical or recurrent febrile urinary tract infections. Initial imaging. CT Abdomen and Pelvis With IV Contrast An IV contrast-enhanced CT scan can be performed selectively when there is suspicion for complications, such as renal abscess or xanthogranulomatous pyelonephritis [80-83].


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast in the evaluation of a child with atypical or recurrent febrile UTI for the initial imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without IV contrast in the evaluation of a child with atypical or recurrent febrile UTI for initial imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. CTU Without and With IV Contrast There is no relevant literature to support the use of CTU in the evaluation of a child with atypical or recurrent febrile UTI for initial imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. DMSA Renal Scan A DMSA renal scan may have limited benefit in patients with VUR and atypical, complicated, or recurrent UTIs. A normal DMSA scan in patients with recurrent infections may exclude high-grade reflux on VCUG and thus direct toward antibiotic treatment without the need for invasive VCUG. The NICE guidelines recommend DMSA renal scan 4 to 6 months after atypical or recurrent infection (<3 years) and for recurrent infection (>3 years) in children [83]. The literature in this patient population is evolving with a focus on other modalities such as VUS and fluoroscopy VCUG. It should be noted that the primary evidence supporting use of DMSA renal scan is generally older than that of other modalities.


Urinary Tract Infection Child

Urinary Tract Infection Child. Fluoroscopy Voiding Cystourethrography Children with recurrent UTIs have an increased prevalence of VUR [43]. Based on multiple studies in a pooled cohort of infants after first UTI and recurrent UTI, the frequency of VUR increases from 35% to 74%, with increased risk for renal scarring with each UTI [1]. A finding of VUR without dilatation of urinary tract may lead to antibiotic prevention treatment, and a finding of dilated VUR may lead to endoscopic or surgical treatment. VCUG is routinely performed for children <6 months of age with atypical UTI and from 6 months to 3 years of age with atypical UTI and abnormalities on renal and bladder US, poor urine flow, or family history of VUR as per the NICE guidelines


Urinary Tract Infection Child

Urinary Tract Infection Child. Urinary Tract Infection-Child [83]. VCUG is not recommended by NICE guidelines for children >3 years of age with UTI, even if atypical or recurrent UTI [16]. The AAP guidelines suggest VCUG for children 2 to 24 months of age after the second febrile UTI and after the first for patients with abnormalities on renal and bladder US [41].


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis with IV contrast in the evaluation of a child with atypical or recurrent febrile UTI for initial imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast in the evaluation of a child with atypical or recurrent febrile UTI for initial imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRU Without and With IV Contrast There is no relevant literature to support the use of MRU in the evaluation of a child with atypical or recurrent febrile UTI for initial imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. Nuclear Medicine Cystography There is good correlation between nuclear medicine cystography and VCUG for the detection of reflux [19]. For more information, please see the fluoroscopic VCUG section. The literature in this patient population is evolving with a focus on other modalities such as VUS and fluoroscopy VCUG. It should be noted that the primary evidence supporting use of nuclear cystography is generally older than that of other modalities.


Urinary Tract Infection Child

Urinary Tract Infection Child. US Kidneys and Bladder In children with atypical, recurrent, or complicated UTI, the main benefit of US is the detection of underlying abnormalities, calculi, or complications such as a renal or perirenal abscess [82,84]. The potential harm of using US as the only imaging for UTI is the poor sensitivity for VUR and pyelonephritis/scarring [25-30,64]. There are limited data showing inconsistent results on the sensitivity of US in the detection of dilated VUR [65,66]. Grayscale US identifies approximately 25% of the patients with acute pyelonephritis and approximately 40% of the patients with chronic parenchymal scarring [29,31,67-72].


Urinary Tract Infection Child

Urinary Tract Infection Child. In a retrospective study of 2,259 children <5 years of age, sensitivity was related to criteria for the definition of a normal study. With the use of the most relaxed criteria (25% abnormal), US had a sensitivity of 28% (specificity of 77%), and with the most stringent criteria (4% abnormal), US had a sensitivity of 5% (specificity of 97%) [31]. Assuming a 40% prevalence of VUR and a 20% recurrent rate of UTIs in 100 children who have US, up to 11 children will have positive US studies that will be followed by a VCUG study, of which 8 will be positive for VUR. Two years of a prophylactic antibiotic will decrease recurrent UTIs from up to 2 children to 1 child. This means that 1 child will benefit from the US study and an additional 3 children that may benefit from prophylactic antibiotic will not be treated. In addition, with the increased use of prenatal US screening, the yield of detection of unknown renal abnormalities in children with UTIs has decreased [73].


Urinary Tract Infection Child

Urinary Tract Infection Child. Few studies with small series of children suggest good correlation between power Doppler US and Tc-99m DMSA findings of pyelonephritis [74,75]. Other studies; however, demonstrated a low sensitivity for pyelonephritis and a low prediction for development of renal scarring [49,76,77]. Therefore, the use of power Doppler US as a replacement for nuclear medicine cystography is not useful [26,49,76].


Urinary Tract Infection Child

Urinary Tract Infection Child. The NICE guidelines for UTI recommend US if the infection is atypical for all ages or recurrent [16]. The AAP guidelines recommend US for children with a febrile UTI from ages 2 to 24 months [41].


Urinary Tract Infection Child

Urinary Tract Infection-Child

Urinary Tract Infection Child. Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. Variant 6: Child. Established vesicoureteral reflux. Follow-up imaging. CT Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis with IV contrast in the evaluation of a child with established VUR for follow-up imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without and with IV contrast in the evaluation of a child with established VUR for follow-up imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. CT Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of CT abdomen and pelvis without IV contrast in the evaluation of a child with established VUR for follow-up imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. CTU Without and With IV Contrast There is no relevant literature to support the use of CTU in the evaluation of a child with established VUR for follow-up imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. DMSA Renal Scan Approximately one-fifth of children may have renal damage after UTI, with significant risk for deterioration [85]. DMSA may be considered for follow-up of children with VUR to detect new renal scarring, especially after a febrile UTI or when renal US is abnormal [61].


Urinary Tract Infection Child

Urinary Tract Infection Child. Fluoroscopy Voiding Cystourethrography VCUG is recommended by the American Urological Association between 12 and 24 months after UTI with longer intervals between follow-up studies in patients in whom evidence supports lower rates of spontaneous resolution (ie, those with higher grades of VUR [grades III-V], bladder/bowel dysfunction, and older age) [61].


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis with IV contrast in the evaluation of a child with established VUR for follow-up imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast in the evaluation of a child with established VUR for follow-up imaging.


Urinary Tract Infection Child

Urinary Tract Infection Child. MRU Without and With IV Contrast MRU has been suggested as a safer alternative to scintigraphy in children with VUR, particularly those who require follow-up imaging [86,87]. This is pertinent for follow-up imaging of VUR causing renal scarring.


Urinary Tract Infection Child

Urinary Tract Infection Child. Nuclear Medicine Cystography Nuclear medicine cystography is recommended by the American Urological Association between 12 and 24 months after UTI with longer intervals between follow-up studies in patients in whom evidence supports lower rates of spontaneous resolution (ie, those with higher grades of VUR [grades III-V], bladder/bowel dysfunction, and older age) [61].


Urinary Tract Infection Child

Urinary Tract Infection Child. US Kidneys and Bladder US is recommended by The American Urological Association for the follow-up imaging in established VUR every 12 months to monitor renal growth and any parenchymal scarring [61]. Grayscale US identifies approximately 40% of patients with chronic parenchymal scarring [29,31,67-72].


Urinary Tract Infection Child

Urinary Tract Infection-Child


Urinary Tract Infection Child

Urinary Tract Infection Child. 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.


Urinary Tract Infection Child

Urinary Tract Infection Child. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Diffuse Lung Disease

Diffuse Lung Disease. Some of the DLDs, such as idiopathic pulmonary fibrosis, demonstrate episodes of acute exacerbation or acute deterioration as a result of the intrinsic DLD itself. These episodes typically manifest with a 1 to 2 month prodrome of worsening dyspnea or cough and progressive lung disease [11-16]. The development of acute exacerbations is not rare and has significant impact on mortality [17]. Clinically, these episodes frequently overlap with other causes of respiratory illness, such as infection, pulmonary embolism, heart failure, or malignancy. These other causes of acute clinical decline are outside the scope of this work and are best addressed in other ACR Appropriateness Criteria documents.


Diffuse Lung Disease

Diffuse Lung Disease. 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.


Diffuse Lung Disease

Diffuse Lung Disease. Reprint requests to: publications@acr.org


Diffuse Lung Disease

Diffuse Lung Disease. Diffuse Lung Disease evaluation of DLD distribution [23-26]. In this document, statements regarding the appropriateness of non-contrast CT include the use of such HRCT sequences based on the suspected DLD and clinical questions.


Diffuse Lung Disease

Diffuse Lung Disease. FDG-PET/CT Skull Base to Mid-Thigh There is limited research supporting the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT in some DLDs, which does not currently support the use of FDG-PET/CT for initial imaging. FDG-PET/CT may have a secondary role for evaluation of some DLDs because of increased FDG activity that correlates with disease severity and prognosis. A majority of relevant studies focus on sarcoidosis and a minority on fibrotic DLD including idiopathic pulmonary fibrosis [85-105].


Diffuse Lung Disease

Diffuse Lung Disease. MRI Chest There is limited research supporting the use of MRI in DLDs, which does not currently support the use of MRI for initial imaging. Small studies have shown adequate concordance of MRI findings with CT in established cases of DLD utilizing a variety of specialized MRI sequences. Some MRI sequences in the setting of DLD may provide additional functional information such as tissue characterization, gas transfer efficiency, and lung elasticity [106- 118].


Diffuse Lung Disease

Diffuse Lung Disease

Diffuse Lung Disease. Diffuse Lung Disease


Diffuse Lung Disease

Diffuse Lung Disease. chest radiograph at time of initial diagnosis of DLD may assist with diagnosis of these other conditions via radiograph on follow-up.


Diffuse Lung Disease

Diffuse Lung Disease. FDG-PET/CT Skull Base to Mid-Thigh There is limited research supporting the use of FDG-PET/CT in some DLDs, which does not currently support FDG-PET/CT for imaging of acute exacerbation or acute deterioration of DLD.


Diffuse Lung Disease

Diffuse Lung Disease. MRI Chest There is limited research supporting the use of MRI in some DLDs, none of which currently supports the use of MRI for imaging of acute exacerbation or acute deterioration of DLD.


Diffuse Lung Disease

Diffuse Lung Disease. FDG-PET/CT Skull Base to Mid-Thigh There is limited research supporting the use of FDG-PET/CT in DLDs. In sarcoidosis, FDG-PET/CT can be used as a marker of disease extent and severity, and it can assist in follow-up and monitoring of treatment response [86,87,89,92,93,95,96,98-100]. Research supporting the use of FDG-PET/CT is more limited in other DLDs but has been evaluated in some studies of lung fibrosis [90,91,102].


Diffuse Lung Disease

Diffuse Lung Disease


Diffuse Lung Disease

Diffuse Lung Disease. MRI Chest There is limited research supporting the use of MRI in DLD, none of which currently supports the use of MRI for follow-up imaging. Small studies have shown adequate concordance of MRI findings with CT in established cases of DLD utilizing a variety of specialized MRI sequences. Some MRI sequences in the setting of DLD may provide additional functional information such as tissue characterization, gas transfer efficiency, and lung elasticity. [106- 118].


Diffuse Lung Disease

Diffuse Lung Disease. Radiography Chest There is no research supporting the use of chest radiography over CT for follow-up imaging of confirmed DLD without acute clinical deterioration. Multiple studies demonstrate the increased sensitivity and specificity of CT over radiographs for evaluation of DLD [38-47,49-51,120,121].


Diffuse Lung Disease

Diffuse Lung Disease. 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.


Diffuse Lung Disease

Diffuse Lung Disease. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Introduction/Background The Centers for Disease Control and Prevention National Diabetes Statistics Report of 2017 states that 30.3 million people in the United States have diabetes (9.4% of the population) [1]. Diabetes-related foot complications, such as soft-tissue infection, osteomyelitis, and neuropathic osteoarthropathy, account for up to 20% of all diabetic-related North American hospital admissions, with up to $1.5 billion spent annually in the United States on diabetic foot ulcer care [2].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Neuropathic changes in the foot are present in about 1% of diabetics [3]. Neuropathic osteoarthropathy is a progressive process affecting the bones, joints, and soft tissue of the foot and ankle. Delay in the diagnosis may lead to derangement of the bony architecture of the foot, deformity, recurrent foot ulcerations, cellulitis, osteomyelitis, and amputation [4].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Discussion of Procedures by Variant Variant 1: Suspected osteomyelitis of the foot in patients with diabetes mellitus. Initial imaging. Radiography Foot Radiographs are useful as the initial screening examination. They evaluate anatomic detail and previous surgeries and are useful to evaluate for other causes of pain, such as radiopaque foreign body, soft-tissue gas, fracture, degenerative changes, neuropathic arthropathy, or tumor. Radiographs are insensitive in the detection of early stages of acute osteomyelitis [11]. Soft-tissue swelling and obscuration of the fat planes will precede osseous changes [12]. Osseous changes may take 10 to 12 days to develop in adults [13]. Early bony changes of osseous infection include periosteal reaction, lytic bone destruction, endosteal scalloping, osteopenia, loss of trabecular architecture, and new bone apposition [13].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. CT Foot There is no relevant literature to support the use of CT with or without intravenous (IV) contrast as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 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.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Reprint requests to: publications@acr.org


Suspected Osteomyelitis of the Foot

Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Suspected Osteomyelitis of the Foot


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. MRI Foot There is no relevant literature to support the use of MRI with or without IV contrast as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. FDG-PET/CT Whole Body There is no relevant literature to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. WBC Scan and Sulfur Colloid Scan Foot There is no relevant literature to support the use of a dual isotope WBC with sulfur colloid scan as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. WBC Scan Foot There is no relevant literature to support the use of In-111 WBC scan as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan and WBC Scan and Sulfur Colloid Scan Foot There is no relevant literature to support the use of combined imaging with 3-phase bone scan and In-111 WBC scan and Tc-99m sulfur colloid scan as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan and WBC Scan Foot There is no relevant literature to support the use of a 3-phase bone scan with In-111 WBC as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan Foot There is no relevant literature to support the use of a 3-phase bone scan as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. US Foot There is no relevant literature to support the use of ultrasound (US) as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan and WBC Scan with SPECT or SPECT/CT foot There is no relevant literature to support the use of single-photon emission computed tomography (SPECT/CT) as the initial screening examination in diabetic patients with suspected osteomyelitis of the foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Variant 2: Soft-tissue swelling without ulcer. Suspected osteomyelitis or early neuropathic arthropathy changes of the foot in patients with diabetes mellitus. Additional imaging following radiographs. The likelihood of developing osteomyelitis without an associated wound or ulceration is extremely low. Almost all osteomyelitis and soft-tissue abscesses of the diabetic foot represent areas of contiguous infection from adjacent skin ulcerations and not hematogenous seeding [14]. Any imaging modality performed for this variant should be able to identify soft-tissue infections, tumors and abscesses, early neuropathic arthropathy, or subtle fractures not revealed on initial radiographs. Diabetic foot osteomyelitis and neuroarthropathy can be difficult to differentiate clinically. The early diagnosis of neuropathic disease prior to the development of radiographic change is important, as these patients will be treated with altered footwear and orthotics to prevent the progression to deformity. US Foot US is of limited benefit in the detection of adult osteomyelitis because of its inability to penetrate the cortex of the bone. The role of US in the diabetic foot includes detection of subperiosteal and soft-tissue abscesses, tenosynovitis, joint effusions, and radiolucent foreign bodies. US is insensitive to the marrow edema and trabecular microfractures present in neuropathic foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. CT Foot CT is able to image large anatomic regions rapidly with multiplanar reconstruction capability. CT with or without IV contrast demonstrates the features of acute osteomyelitis, such as periosteal reaction, endosteal scalloping, and lytic bone destruction, more clearly and in more detail than on radiographs but is less sensitive than MRI and nuclear medicine studies for detecting early intramedullary changes of acute osteomyelitis [15]. Features of chronic osteomyelitis (sequestra, involucrum, cloaca, sinus tracts) are well depicted on CT with or without IV contrast. CT with or without IV contrast may be superior to MRI for the findings of sequestra, foreign bodies, and


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Suspected Osteomyelitis of the Foot soft-tissue gas [16]. CT with or without IV contrast is more sensitive than radiographs to osseous changes allowing earlier detection of neuropathic arthropathy changes of debris, fragmentation, disruption, and dislocation [3,17]. When metal is present in or near the area of interest, there is significant loss of image resolution that is due to a beam-hardening artifact [13]. Dual-energy CT may be useful for metal artifact reduction if available. With high-resolution multiplanar imaging, CT is able to delineate the anatomic extent of soft-tissue infections. Contrast is preferred for the evaluation of soft-tissue infection and delineation of fluid collections [16].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. MRI Foot MRI with or without enhancement demonstrates excellent soft-tissue contrast and sensitivity to marrow abnormalities [18,19] with high-resolution detail in multiple anatomic planes. The likelihood of osteomyelitis without an associated wound or ulceration is extremely low. MRI with or without enhancement is a good modality to identify other potential sources of pain in this variant, such as soft-tissue infections, tumors and abscesses, early neuropathic arthropathy, or subtle fractures. Normal marrow signal reliably excludes osteomyelitis [20]. Positive cases of osteomyelitis demonstrate decreased T1-weighted bone marrow signal and increased signal on fluid-sensitive sequences [21,22]. Some authors suggest increased T2-weighted bone marrow signal may represent early osteomyelitis or be a predictor of later development of osteomyelitis, even in the setting of a normal T1-weighted signal [2]. MRI with or without enhancement is often the modality of choice in this variant because of its high sensitivity for osteomyelitis [23-25]. MRI with or without IV contrast can detect the earliest findings of neuropathic arthropathy, such as marrow edema and trabecular microfractures [17,26]. A negative MRI indicates that acute neuropathic arthropathy is unlikely [27]. MRI may be limited by artifact secondary to orthopedic hardware.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan Foot The 3-phase bone scan is sensitive but not specific in differentiating osteomyelitis from a neuropathic foot since both processes cause increased osteoblastic activity [30]. Pathologies with high bone turnover, such as fracture, neuroarthropathy, malignancy, or recent surgery, may result in a positive scan in the absence of infection. A negative bone scan excludes infection with a high degree of certainty [31]. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan and WBC Scan Foot The combined bone scan and labeled leukocyte scan (In-111 or Tc-99m) markedly improves specificity in the nonmarrow-containing skeleton when there has been previous surgery, radiographs are abnormal, or when any other cause for bone remodeling is present [32]. It can be useful for distinguishing true WBC accumulation secondary to osteomyelitis from nonspecific WBC uptake that is seen in neuropathic joint [32,33]. Planar scintigraphic imaging modalities alone have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. WBC Scan Foot Labeled leukocyte imaging is advantageous for imaging acute infection in immunocompetent patients with intact chemotaxis. The modality is most useful for identifying neutrophil-mediated inflammatory processes, such as bacterial infections, because the majority of leukocytes labeled are neutrophils, and it is less useful in illnesses in which the predominant cellular response is other than neutrophilic, such as tuberculosis. Chronicity of infection and nonspecific inflammation may lead to inconsistent results, and a recent onset neuropathic joint may yield false-positive results [34,35]. Planar scintigraphic imaging modalities have relatively low spatial resolution and lack of anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Suspected Osteomyelitis of the Foot WBC Scan and Sulfur Colloid Scan Foot Combined labeled leukocyte and sulfur colloid bone marrow imaging is most useful when increased labeled leukocyte activity is secondary to altered bone marrow distribution, such as around joint prosthesis [36]. Labeled leukocytes and sulfur colloid normally accumulate in bone marrow, and discordant labeled white cell activity without corresponding sulfur colloid uptake indicates infection [37]. Planar scintigraphy imaging modalities alone have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan and WBC Scan and Sulfur Colloid Scan Foot Combined labeled leukocyte and sulfur colloid bone marrow imaging is most useful when increased labeled leukocyte activity is secondary to altered bone marrow distribution, such as around joint prostheses [36]. In evaluating arthroplasties, positive bone scan and WBC uptake with no uptake on the bone marrow scan is considered positive for infection [38]. This modality may be helpful when significant metal hardware is present that would impair MRI or CT imaging. Planar scintigraphic imaging modalities have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. FDG-PET/CT Whole Body FDG-PET/CT has potentially an important role in diagnosing deep soft-tissue infection and osteomyelitis and in differentiating neuropathic arthropathy [39,40]. The high resolution of FDG-PET/CT offers an advantage over single-photon emitting tracers, particularly when evaluating precise localization of radiotracer accumulation in bones of the distal forefoot, where the majority of diabetic foot infections occur [41]. Fused FDG-PET/CT allows correct differentiation between osteomyelitis and soft-tissue infection [42,43]. FDG-PET/CT can be used in the evaluation of patients with metal implants that would compromise the accuracy of MRI or CT [40]. Prior studies have demonstrated high accuracy in the detection of osteomyelitis in cases complicated by prior surgery, trauma, and the presence of orthopedic hardware [44-46].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan and WBC Scan with SPECT or SPECT/CT Foot Planar scintigraphic imaging modalities have relatively low spatial resolution and lack anatomic specificity. SPECT/CT fused imaging improves the diagnostic accuracy mainly because of accurate anatomic localization [47-50]. Dual isotope SPECT/CT is reported to be more accurate than bone scan SPECT/CT or WBC-SPECT/CT alone [51].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Variant 3: Soft-tissue swelling with ulcer. Suspected osteomyelitis of the foot in patients with diabetes mellitus with or without neuropathic arthropathy. Additional imaging following radiographs. Imaging plays a central role in characterizing soft-tissue and osseous infections in the diabetic foot by identifying the location, evaluating the extent of involvement, and detecting complications, such as soft-tissue abscesses or sinus tracts. The infected ulcer may progress to soft-tissue abscess, sinus tract, infected tendon sheath, osteomyelitis, or septic arthritis [29]. If an ulcer with a positive probe-to-bone test is present, the risk of osteomyelitis is 12% to 66% [52-54]. The role of any imaging modality in these patients is to confirm the presence of soft-tissue or osseous infection and determine the anatomic extent for treatment planning.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. US Foot US demonstrates limited benefit in the detection of adult osteomyelitis because of its inability to penetrate the cortex of the bone. The role of US in the diabetic foot includes detecting subperiosteal and soft-tissue abscesses, tenosynovitis, joint effusions, and radiolucent foreign bodies. US is insensitive to the marrow edema and trabecular microfractures present in neuropathic foot.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. CT Foot CT is able to image large anatomic regions rapidly with multiplanar capability. CT with or without IV contrast demonstrates the features of acute osteomyelitis, such as periosteal reaction, endosteal scalloping, and lytic bone destruction, more clearly and in more detail than on radiographs, but is less sensitive than MRI and nuclear medicine studies for detecting early intramedullary changes of acute osteomyelitis [15]. Features of chronic osteomyelitis (sequestra, involucrum, cloaca, sinus tracts) are well depicted on CT with or without IV contrast. CT with or without IV contrast may be superior to MRI for the findings of sequestra, foreign bodies, and soft- tissue gas [16]. CT with or without IV contrast is more sensitive than radiographs to osseous changes, allowing


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Suspected Osteomyelitis of the Foot earlier detection of neuropathic arthropathy changes of debris, fragmentation, disruption, and dislocation [3,17]. When metal is present in or near the area of interest, there is significant loss of image resolution that is due to a beam-hardening artifact [13]. Dual-energy CT may be useful for metal artifact reduction if available. With high- resolution multiplanar imaging, CT is able to delineate the anatomic extent of soft-tissue infections. Contrast is preferred for the evaluation of soft-tissue infection and delineation of fluid collections [16].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. MRI Foot MRI with or without enhancement is the favored modality in this variant and has demonstrated high sensitivity (90%) and specificity (83%) for early osteomyelitis in a large meta-analysis [23]. MRI with or without enhancement demonstrates excellent soft-tissue contrast and sensitivity to marrow abnormalities [18,19] with high-resolution detail in multiple anatomic planes. Normal marrow signal reliably excludes osteomyelitis [20]. Positive cases of osteomyelitis demonstrate decreased T1-weighted bone marrow signal and increased signal on fluid-sensitive sequences [21,22]. Some authors suggest increased T2-weighted bone marrow signal may represent early osteomyelitis or be a predictor of later development of osteomyelitis, even in the setting of a normal T1-weighted signal [2]. The high resolution can delineate the anatomic extent of osteomyelitis and assist in surgical planning [29]. MRI with or without IV contrast can detect the earliest findings of neuropathic arthropathy, such as marrow edema and trabecular microfractures [17,26]. A negative MRI indicates that acute neuropathic arthropathy is unlikely [27]. MRI may be limited by artifact secondary to orthopedic hardware.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 3-phase Bone Scan Foot The 3-phase bone scan is sensitive but not specific in differentiating osteomyelitis from a neuropathic foot since both processes cause increased osteoblastic activity [30]. Pathologies with high bone turnover, such as fracture, neuroarthropathy, malignancy, or recent surgery, may result in a positive scan in the absence of infection. A negative bone scan excludes infection with a high degree of certainty [31]. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery. In the setting of deep soft-tissue ulceration, positive uptake in the adjacent bone is highly suggestive of osteomyelitis.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. WBC Scan and Sulfur Colloid Scan Foot Combined labeled leukocyte and sulfur colloid bone marrow imaging is most useful when increased labeled leukocyte activity is secondary to altered bone marrow distribution, such as around joint prosthesis [36]. Labeled


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Suspected Osteomyelitis of the Foot leukocytes and sulfur colloid normally accumulate in bone marrow, and discordant labeled white cell activity without corresponding sulfur colloid uptake indicates infection image [37]. Planar scintigraphic imaging modalities alone have relatively low spatial resolution and lack anatomic specificity. Nuclear medicine modalities are useful in cases where infection is multifocal or when the infection is associated with orthopedic hardware or chronic bone alterations from trauma or surgery.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. FDG-PET/CT Whole Body FDG-PET/CT has potentially an important role in diagnosing deep soft-tissue infection and osteomyelitis and differentiating neuropathic arthropathy [39,40]. The high resolution of FDG-PET/CT offers an advantage over single-photon emitting tracers, particularly when evaluating precise localization of radiotracer accumulation in bones of the distal forefoot, where the majority of diabetic foot infections occur [41]. Fused FDG-PET/CT allows correct differentiation between osteomyelitis and soft-tissue infection [42,43]. FDG-PET/CT can be used in the evaluation of patients with metal implants that would compromise the accuracy of MRI or CT [40]. Previous studies have demonstrated high accuracy in the detection of osteomyelitis in cases complicated by prior surgery, trauma, and the presence of orthopedic hardware [44-46].


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. 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.


Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. For additional information on the Appropriateness Criteria methodology and other supporting documents go to www.acr.org/ac.


Suspected Osteomyelitis of the Foot

Suspected Osteomyelitis of the Foot in Patients with Diabetes Mellitus. Suspected Osteomyelitis of the Foot


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Introduction/Background An adrenal incidentaloma is an unsuspected asymptomatic mass, usually detected on a radiologic study that was obtained for purposes unrelated to adrenal disease [1,2]. The prevalence of incidentally discovered adrenal masses ranges from 4% to 10% on radiological studies, depending on patient age, and from 1% to 8.7% in autopsy specimens [3]. The majority of incidentalomas are benign and most are nonhyperfunctioning adenomas. The prevalence of adenomas in the general population ranges from 1% to 2% [4], although autopsy studies have shown rates as high as 6.6% to 8.7%, depending on the age distribution of the patients. The risk of primary adrenocortical carcinoma in the general population is quite small, on the order of 0.06%; however, among patients with known adrenal masses, the risk is reported to be as high as 4.7% [4]. Other adrenal malignancies, such as angiosarcoma, lymphoma, and pheochromocytoma, are rare in the general population.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Many other criteria are involved in the assessment of incidental adrenal masses, including size, growth or stability, and endocrine function. Size is an important variable in predicting malignancy of an incidentally discovered adrenal mass. Smaller lesions are usually benign [11]; therefore, incidental adrenal masses with <1 cm short axis measurement do not generally require further evaluation because of the overwhelming likelihood that these lesions are benign [12]. Conversely, larger lesions have a greater likelihood of being malignant. In addition, interval growth of adrenal masses has also been advocated as a potential indicator of malignancy.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. If prior imaging is available, and a lesion has been stable for 1 year or more, it can generally be considered benign [12,13]. Even though incidentally discovered adrenal masses are by definition asymptomatic, a proportion will show subclinical function. Current guidelines from the Association of Clinical Endocrinologist and American Association


Adrenal Mass Evaluation

Adrenal Mass Evaluation. aCleveland Clinic, Cleveland, Ohio. bCleveland Clinic, Cleveland, Ohio. cPanel Chair, Northwestern University, Chicago, Illinois. dPanel Vice-Chair, UT Southwestern Medical Center, Dallas, Texas. eUniversity of Rochester Medical Center, Rochester, New York. fThe University of Texas MD Anderson Cancer Center, Houston, Texas. gUniversity of Washington, Seattle, Washington; American Urological Association. hDuke University Medical Center, Durham, North Carolina. iEmory University School of Medicine, Atlanta, Georgia. jThomas Jefferson University Hospital, Philadelphia, Pennsylvania. kBrigham & Women's Hospital, Boston, Massachusetts. lCleveland Clinic, Cleveland, Ohio. mMedical University of South Carolina, Charleston, South Carolina; American Urological Association. nUniversity of Alabama at Birmingham, Birmingham, Alabama. oUniversity of California San Francisco School of Medicine, San Francisco, California. pJohns Hopkins University School of Medicine, Washington, District of Columbia. qUniversity of Maryland School of Medicine, Baltimore, Maryland. rRhode Island Hospital/The Warren Alpert Medical School of Brown University, Providence, Rhode Island. sSpecialty Chair, University of Alabama at Birmingham, Birmingham, Alabama.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. 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.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Reprint requests to: publications@acr.org


Adrenal Mass Evaluation

Adrenal Mass Evaluation

Adrenal Mass Evaluation. Adrenal Mass Evaluation


Adrenal Mass Evaluation

Adrenal Mass Evaluation. of Endocrine Surgeons recommend biochemical evaluation of all adrenal incidentalomas to exclude presence of hyperfunctioning lesion [14].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Special Imaging Considerations Adrenal CT A dedicated adrenal CT protocol consists of unenhanced thin-section images through the upper abdomen with axial and coronal reformatted images. This allows for initial attenuation measurement of the mass. If diagnostic benign imaging characteristics are not present, a contrast-enhanced series can be performed between 60 and 90 seconds after the administration of intravenous (IV) contrast followed by a 15-minute delayed-phase imaging for evaluation of washout characteristics [15,16]. A study that substituted a 10-minute delayed-phase scan was found to have diminished sensitivity to adenomas compared with a 15-minute delay and is not generally utilized [15].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. MRI MR chemical shift imaging (CSI) relies on differences in fat and water molecule precession frequencies and consists of T1-weighted in-phase and opposed-phase dual-echo gradient-recalled echo sequences when both echoes are obtained in the same breath hold. The opposed-phase echo is obtained before the in-phase echo, and lesions with intracytoplasmic fat will be detected by signal intensity loss when opposed-phase images are compared with in- phase images [17]. If MR-CSI is indeterminate, the addition of dynamic postcontrast imaging without or with the addition of T2-weighted imaging has been shown to aid in the diagnosis of adenoma [18-20].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Molecular Imaging PET can be utilized for evaluation of different adrenal abnormalities. Fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET can detect hypermetabolic metastatic lesions. Patients are required to fast for 4 to 6 hours prior to injection of FDG, and data are acquired approximately 60 to 120 minutes after injection. A CT or MRI, respectively, is obtained and a PET scan that covers the same field of view. Co-registered images are then displayed on a workstation for analysis [21]. FDG, 18-F-dihydroxylphenylaalanine (DOPA), Ga-68-DOTATATE, or I-123 metaiodobenzylguanidine (MIBG) can be utilized to identify hyperfunctioning tumors, such as pheochromocytoma. FDG-PET/CT is a modality that can further characterize whether a mass is benign versus malignant, as malignant lesions have increased metabolic activity and, therefore, increased glucose avidity compared with benign lesions. Both qualitative and quantitative assessment using standard uptake values (SUVs) is performed to evaluate a lesion. Malignant lesions show increased activity compared with benign lesions with a sensitivity between 93% and 100% [22]. If pheochromocytoma is suspected, then FDG, DOPA, DOTATATE, or MIBG studies can be utilized to improve detection when anatomic localization is inconclusive, to identify additional lesions in the setting of hereditary disease, or to evaluate for metastatic disease [23].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Discussion of Procedures by Variant Variant 1: Indeterminate adrenal mass, less than 1 cm on initial imaging. No diagnostic benign imaging features. No history of malignancy. For patients with no prior history of malignancy and an incidentally detected adrenal mass <1 cm without diagnostic benign imaging characteristics on initial study, the mass is most likely benign [12,24]. One study by Herrera et al [5] examined 342 patients without a history of malignancy and found that the rate of malignancy in adrenal nodules was only 1.5% and that all malignant lesions were >5 cm.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Although many guidelines exist regarding the appropriate time interval for follow-up of adrenal nodules, no agreement has been achieved. Stability of a lesion should be assessed by repeat imaging for nodules >1 cm, but there is no literature supporting further evaluation of lesions <1 centimeter.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. CT Abdomen For lesions <1 cm and no history of malignancy, there is no primary evidence supporting the use of CT for initial evaluation. Metastatic disease to the adrenal gland without a known history of primary malignancy is unusual [4,5]. In a study of 1,049 incidental adrenal masses in patients with no known history of cancer, none were malignant. The majority of lesions were adrenal adenomas, myelolipomas, and cysts [6].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. FDG-PET/CT Skull Base to Mid-Thigh For lesions <1 cm and no history of malignancy, there is no primary evidence supporting the use of FDG-PET/CT for initial evaluation. Metastatic disease to the adrenal gland without a known history of primary malignancy is unusual [4,5]. In a study of 1,049 incidental adrenal masses in patients with no known history of cancer, none were malignant. The majority of lesions were adrenal adenomas, myelolipomas, and cysts [6].


Adrenal Mass Evaluation

Adrenal Mass Evaluation


Adrenal Mass Evaluation

Adrenal Mass Evaluation. It is recognized that FDG-PET is less sensitive and specific for lesions <10 mm [25], and although PET has the potential to detect very small adrenal metastases, one study showed that 2 of 5 lesions that proved to be false- negative for malignancy on PET were <10 mm [26]. Therefore, the specificity of FDG-PET for characterizing adrenal lesions <10 mm may be limited.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Image-Guided Biopsy Adrenal Gland For lesions <1 cm and no history of malignancy, there is no primary evidence supporting the use of biopsy for initial evaluation [27-30].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. MRI Abdomen For lesions <1 cm and no history of malignancy, there is no primary evidence supporting the use of MRI for initial evaluation. Metastatic disease to the adrenal gland without a known history of primary malignancy is unusual [4,5]. In a study of 1,049 incidental adrenal masses in patients with no known history of cancer, none were malignant. The majority of lesions were adrenal adenomas, myelolipomas, and cysts [6].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Variant 2: Indeterminate adrenal mass, 1 to 2 cm on initial imaging. No diagnostic benign imaging features. No history of malignancy. Follow-up imaging in 12 months. For patients with no prior history of malignancy and an incidentally detected adrenal mass between 1 and 2 cm without diagnostic benign imaging characteristics on initial study, the mass is most likely benign [12,24]. One study by Herrera et al [5] examined 342 patients without a history of malignancy and found that the rate of malignancy in adrenal nodules was only 1.5% and that all malignant lesions were >5 cm. In another series of 887 patients who had adrenal incidentalomas, a diameter of >4 cm was shown to have 90% sensitivity for the detection of adrenocortical carcinoma but low specificity; only 24% of lesions >4 cm in diameter were malignant [27].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Although many guidelines exist regarding the appropriate time interval for follow-up, no agreement has been achieved. Stability of a lesion >1 cm should be assessed by repeat imaging. If prior imaging is or becomes available or a lesion has been stable for 1 year or more, it can generally be considered benign and no additional imaging follow-up is required; however, imaging may be performed per clinical discretion [13,31]. Therefore, in this clinical scenario, follow-up adrenal-specific imaging can be considered at 12 months to ascertain whether there are benign imaging features and ensure the mass is stable in size.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Although both benign and malignant adrenal masses can enlarge over time, interval growth of adrenal masses has been advocated as a potential indicator of malignancy. However, there is scant information on what size change over what time interval requires further investigation. A study has shown that a growth of 0.8 cm on follow-up CT had the highest combination of sensitivity (72%) and specificity (81%) when evaluating absolute size change, growth rate, and growth percent in 111 benign and 25 malignant pathologically proven adrenal lesions. Although the unadjusted odds ratio for this threshold was 11.02, no threshold was found with 100% sensitivity or specificity [32]. Another study of 105 adenomas and 26 malignant nodules found that approximately one-third of adenomas grew, all at a rate of <0.3 cm/year, whereas all malignant nodules grew at a rate of >0.5 cm/year [33].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. CT Abdomen Evaluation of an adrenal mass indeterminate on initial imaging consists of an adrenal CT protocol. Unenhanced thin-section images through the upper abdomen are obtained and then reviewed to evaluate for diagnostic benign imaging features. Some benign lesions, such as cysts and myelolipomas, are readily characterized by CT. Adrenal adenomas contain lipid to varying degrees, and this lowers their attenuation coefficient on unenhanced CT. A threshold value of 10 HU is generally accepted as a cutoff value for diagnosing a lipid-rich adenoma, as the 10 HU threshold has a sensitivity of 71% and specificity of 98% for adenomas [34].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. As the threshold value for the HU unit cutoff is increased (for example from 0 to 10 HU), the sensitivity for adenomas increases; however, so does the false-positive rate [35,36]. Lesions that do not contain intracellular lipid (adenoma) or macroscopic fat (myelolipoma) on CT are evaluated with pre- and postcontrast imaging. If there is no enhancement, the lesion may be characterized as a benign lesion such as a cyst or hemorrhage.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. The use of washout CT may increase the accuracy of characterization compared with MRI. In one small study, washout CT was slightly superior to MR-CSI in characterizing adrenal masses that measured >10 HU on unenhanced CT [42]. Another study demonstrated that washout CT is more accurate than MR-CSI characterization of hyperattenuating adrenal masses, regardless of history of malignancy [43]. Routine abdominal CT without IV contrast will often provide definitive evidence of adenoma. Routine abdominal CT with IV contrast is rarely diagnostic and should not be considered for characterization of a known adrenal lesion.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. FDG-PET/CT Skull Base to Mid-Thigh For lesions measuring 1 to 2 cm and no history of malignancy, there is no primary evidence supporting the use of FDG-PET/CT for initial evaluation.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Metastatic disease to the adrenal gland without a known history of primary malignancy is unusual [4,5]. In a study of 1,049 incidental adrenal masses in patients with no known history of cancer, none were malignant. The majority of lesions were adrenal adenomas, myelolipomas, and cysts [6].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. SUVs are typically greater for metastatic disease [21]. However, mild activity can be seen in benign adenomas (typically less than background liver), thus potentially leading to false-positive interpretations. Studies have predominantly evaluated FDG-PET or FDG-PET/CT in patients with cancer. However, Tessonnier et al [44] evaluated 41 adrenal tumors in 37 patients who had no history of malignancy using FDG-PET/CT. All tumors were without diagnostically benign features on CT or MRI. In this small series, a tumor/liver SUVmax ratio >1.8 yielded 100% sensitivity and specificity for malignancy.


Adrenal Mass Evaluation


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Image-Guided Biopsy Adrenal Gland For lesions measuring 1 to 2 cm and no history of malignancy, there is no primary evidence supporting the use of biopsy for initial evaluation [27-30].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Most studies on the efficacy of adrenal biopsy have been performed in a mixed population of patients. Biopsy samples insufficient to make a diagnosis are obtained in 4% to 19% (mean = 15%) of cases [7,45-47]. When sufficient material is obtained, the accuracy of biopsy is between 96% and 100% for malignant lesions. In one study, rates of positive biopsy in three groups with prior diagnosis of cancer, those with previously undiagnosed cancer with simultaneous masses suspicious for metastases, and those with isolated incidentalomas showed positive biopsy results of 70.6%, 69.0%, and 16.7%, respectively. In all three groups, size was a significant predictor of malignancy. Benign incidentalomas in all three groups had a mean measurement of 2.1 cm, and malignancies had a mean measurement of 9.3 cm [48].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Fine-needle aspiration alone cannot reliably be used to differentiate adrenocortical carcinoma from adrenal adenoma. In addition, the sensitivity of needle biopsy for adrenocortical carcinoma is low. In one study, the sensitivity of needle biopsy for detecting adrenocortical carcinoma was reported as 50% [48]. Another study reports the maximal sensitivity as 70% [49]. In addition, percutaneous biopsy of adrenal lesions is not without risk. Complication rates range from 8% to 12% and consist of bleeding, pneumothorax, infection, and anecdotes of tumor seeding of needle instability should a clinically unsuspected pheochromocytoma be biopsied.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Careful correlation with clinical and endocrinological data is needed, combined with knowledge of other features, such as tumor size and imaging characteristics, to distinguish adenoma from carcinoma due to the possibility of sampling error. Thus, biopsy is better suited to a population with a high risk of malignant lesions and is most useful when noninvasive imaging studies are negative or inconclusive.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. MRI Abdomen Qualitative and quantitative MRI methods have been used to distinguish between adenomas and nonadenomas. An unenhanced MR-CSI (in-phase and opposed-phase gradient-echo scans) relies on differentiating lesions by their


Adrenal Mass Evaluation

Adrenal Mass Evaluation

Adrenal Mass Evaluation. Adrenal Mass Evaluation


Adrenal Mass Evaluation

Adrenal Mass Evaluation. relative lipid content, with malignant lesions having virtually no lipid [50]. This has been shown to be correct for 96% to 100% of cases, depending on the study [51,52]. However, these studies were performed in a mixed population of patients with regard to their history of malignancy, so results may not be directly applicable to populations either with or without known malignancy. Several other authors have shown excellent results in characterizing masses in populations with incidentally detected adrenal masses using simpler CSI techniques [53- 55].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. In cases where the unenhanced CT measurement was between 10 and 30 HU (ie, indeterminate by CT), applying CSI can be discriminatory. In one study, 89% of adenomas with densities between 10 and 30 HU were correctly characterized by CSI [59]. Another study concluded that up to 60% of lesions misclassified by unenhanced CT attenuation measurements can be correctly characterized as adenomas by MR-CSI [53]. Gabriel et al [60] have demonstrated that even heterogeneous loss of signal is evidence of a benign lesion. Thus, MR-CSI may have better sensitivity and specificity than nonenhanced CT.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Diffusion-weighted MRI techniques have been investigated in helping to distinguish benign and malignant masses in various organ systems. Neither Miller et al [61] nor Tsushima et al [62] found that this technique could differentiate adrenal adenomas and nonadenomas.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. A number of series have studied adrenal lesion amount of contrast enhancement and enhancement pattern on MRI after indeterminate MR-CSI [18-20]. In one series of 46 lipid-poor adrenal lesions, the combination of T2-signal intensity and contrast enhancement could identify adenomas with a sensitivity of 84% to 89%, specificity of 96%, and accuracy of 91% to 94% [20]. Additionally, MRI without and with IV contrast may be considered if there is concern for pheochromocytoma, as the contrast can show the typical bright enhancement of this lesion. Contrast can also confirm lack of enhancement of a cystic lesion.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Variant 3: Indeterminate adrenal mass, greater than 2 cm and less than 4 cm on initial imaging. No diagnostic benign imaging features. No history of malignancy. Adrenal specific imaging. For patients with no prior history of malignancy and an incidentally detected adrenal mass without diagnostic benign imaging characteristics >2 cm and <4 cm, dedicated adrenal-specific imaging can be considered at the time of detection to determine if the mass can be diagnosed to be an adenoma [16,37,63]. If adrenal-specific imaging is nondiagnostic, a 6- to 12-month follow-up examination can be performed to document stability [12].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. One study by Herrera et al [5] examined 342 patients without a history of malignancy and found that the rate of malignancy in adrenal nodules was only 1.5% and that all malignant lesions were >5 cm. In another series of 887 patients who had adrenal incidentalomas, a diameter >4 cm was shown to have 90% sensitivity for the detection of adrenocortical carcinoma but low specificity; only 24% of lesions >4 cm in diameter were malignant [27].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Although many guidelines exist regarding the appropriate time interval for follow-up, no true agreement has been achieved. Stability of a lesion should be assessed by repeat imaging, if possible in the same modality as initial imaging to allow for accurate comparison. If prior imaging is or becomes available or a lesion has been stable for 1 year or more, it can generally be considered benign, and no additional imaging follow-up is required [12,13]; however, it may be performed per clinical discretion.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. Although both benign and malignant adrenal masses can enlarge over time, interval growth of adrenal masses has been advocated as a potential indicator of malignancy. However, there is scant information on what size change over what time interval requires further investigation. A study has shown that a growth of 0.8 cm on follow-up CT had the highest combination of sensitivity (72%) and specificity (81%) when evaluating absolute size change, growth rate, and growth percent in 111 benign and 25 malignant pathologically proven adrenal lesions. Although the unadjusted odds ratio for this threshold was 11.02, no threshold was found with 100% sensitivity or specificity [32].


Adrenal Mass Evaluation

Adrenal Mass Evaluation


Adrenal Mass Evaluation

Adrenal Mass Evaluation. CT Abdomen Evaluation of an adrenal mass indeterminate on initial imaging consists of an adrenal CT protocol. Unenhanced thin-section images through the upper abdomen are obtained and then reviewed to evaluate for diagnostic benign imaging features. Some benign lesions such as cysts and myelolipomas are readily characterized by CT. Adrenal adenomas contain lipid to varying degrees, and this lowers their attenuation coefficient on unenhanced CT. A threshold value of 10 HU is generally accepted as a cutoff value for diagnosing a lipid-rich adenoma, as the 10-HU threshold has a sensitivity of 71% and specificity of 98% for adenomas [34].


Adrenal Mass Evaluation

Adrenal Mass Evaluation. As the threshold value for the HU cutoff is increased (for example from 0 HU to 10 HU), the sensitivity for adenomas increases; however, so does the false-positive rate [35,36]. Lesions that do not contain intracellular lipid (adenoma) or macroscopic fat (myelolipoma) on CT are evaluated with pre- and postcontrast imaging. If there is no enhancement, the lesion may be characterized as a benign lesion, such as a cyst or hemorrhage.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. The use of washout CT may increase accuracy of characterization compared with MRI. In one small study, washout CT was slightly superior to MR-CSI in characterizing adrenal masses that measured >10 HU on unenhanced CT [42]. Another study demonstrated that washout CT is more accurate than MR-CSI characterization of hyperattenuating adrenal masses, regardless of history of malignancy [43]. Routine abdominal CT without IV contrast often will provide definitive evidence of adenoma. Routine abdominal CT with IV contrast is rarely diagnostic and should not be considered for characterization of a known adrenal lesion.


Adrenal Mass Evaluation

Adrenal Mass Evaluation. FDG-PET/CT Skull Base to Mid-Thigh For lesions >2 cm and <4 cm and no history of malignancy, there is no primary evidence supporting the use of FDG-PET/CT for initial evaluation.