Biliary Disorders, Anomalies, and Malignancies in Children.

Biliary abnormalities in children are uncommon, and the spectrum of biliary disorders is broader than in adult patients. Unlike in adults, biliary disorders in children are rarely neoplastic and are more commonly rhabdomyosarcoma rather than cholangiocarcinoma. Pediatric biliary disorders may be embryologic or congenital, such as anatomic gallbladder anomalies, anomalous pancreaticobiliary tracts, various cholestatic processes, congenital cystic lesions, or genetic conditions. They may also be benign, such as biliary filling anomalies, biliary motility disorders, and biliary inflammatory and infectious disorders. Distinguishing these entities with a single imaging modality is challenging. US is the primary imaging modality for initial evaluation of biliary abnormalities in children, due to its wide availability, lack of ionizing radiation, and low cost and because it requires no sedation. Other examinations such as MRI, CT, and nuclear medicine examinations may provide anatomic and functional information to narrow the diagnosis further. Hepatobiliary-specific contrast material with MRI can provide better assessment of biliary anatomy on delayed images than can traditional MRI contrast material. MR cholangiopancreatography (MRCP) allows visualization of the intra- and extrahepatic biliary ducts, which may not be possible with endoscopic retrograde cholangiopancreatography (ERCP). Suspected biliary atresia requires multiple modalities for diagnosis and timely treatment. Determining the type of choledochal cyst calls for a combination of initial US and MRCP. Many benign and malignant biliary masses require biopsy for definitive diagnosis. Knowledge of the imaging appearances of different pediatric biliary abnormalities is necessary for appropriate imaging workup, providing a diagnosis or differential diagnosis, and guiding appropriate management. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Imaging Characteristics of and Multidisciplinary Management Considerations for Atypical Ductal Hyperplasia and Flat Epithelial Atypia: Review of Current Literature.

High-risk lesions of the breast are frequently encountered in percutaneous biopsy specimens. While benign, these lesions have historically undergone surgical excision due to their potential to be upgraded to malignancy. However, there is emerging evidence that a tailored management approach should be considered to reduce overtreatment of these lesions. Flat epithelial atypia (FEA) and atypical ductal hyperplasia (ADH) are two of the most commonly encountered high-risk lesions. FEA has been shown to have a relatively low rate of progression to malignancy, and some guidelines are now recommending observation over routine excision in select cases. Selective observation may be reasonable in cases where the target lesion is small and completely removed at biopsy and when there are no underlying risk factors, such as a history of breast cancer or genetic mutation or concurrent ADH. ADH has the highest potential upgrade rate to malignancy of all the high-risk lesions. Most society guidelines continue to recommend surgical excision of this lesion. More recently, some literature suggests that ADH lesions that appear completely removed at biopsy, involve limited foci (less than two or three) with no necrosis or significant atypia, manifest as a small group of mammographic calcifications, or demonstrate no enhancement at MRI may be reasonable for observation. Ultimately, management of all high-risk lesions must be based on a multidisciplinary approach that considers all patient, radiologic, clinical, and histopathologic factors. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Pictorial Review of Common and Uncommon Pediatric Breast Lesions.

Breast masses in children and adolescents are uncommon, and the spectrum of pediatric breast masses is predominantly benign and different from that in adults. Knowledge of the clinical presentation and imaging features of the various stages of normal development and mass-forming lesions in the pediatric breast can guide a tailored imaging approach and help the radiologist make a definitive diagnosis. Breast development begins during fetal gestation along the embryologic milk lines and continues through puberty as the breast matures through the Tanner stages of development. Normal and developmental variants and benign neoplastic and nonneoplastic lesions in the pediatric breast are common causes of concern. Malignant breast masses in children are rare and are more often due to metastasis than primary breast cancer. When clinically warranted, US is the mainstay for imaging the pediatric breast and requires careful correlation of sonographic findings with patient age and history. Breast MRI can be used to further characterize lesions and evaluate the extent of disease. Biopsy should be considered only for suspicious findings and must be weighed against the risk of iatrogenic injury to the developing breast. Given that the majority of mass-forming lesions in the pediatric breast are benign, the diagnostic and management approach should emphasize "first do no harm." Knowledge of the imaging appearance of normal breast development and the spectrum of benign and malignant pediatric breast masses is necessary to make the correct diagnosis. © RSNA, 2022.

Efficacy of MRI-Directed Breast Ultrasound and Lesion Characteristics Affecting Visualization on Breast Ultrasound.

OBJECTIVE: To assess the efficacy of magnetic resonance imaging (MRI)-directed ultrasound (US) in further characterizing lesions detected on MRI and to evaluate the correlation between lesion characteristics and their visibility on US. METHODS: A retrospective review was performed of the records of patients with breast abnormalities detected on MRI between May 2018 and December 2020. All patients who were given a Breast Imaging-Reported and Data System Assessment Category 4 or 5 on breast MRI and sent to breast US for assessment of the MRI abnormality were included. Patients lost to follow-up or those who did not get their subsequent ultrasound at our institution were excluded. The following factors were recorded for all lesions described on the MRI reports: breast density, degree of background parenchymal enhancement, type of MRI finding (mass, areas of non-mass enhancement [NME], enhancing focus), largest dimension, T2 signal intensity, kinetics, shape, margins, enhancement pattern, and presence of ipsilateral breast malignancy. For the subset of the lesions that were identified on MRI-directed US, we recorded the following sonographic features: largest dimension, shape, and margin. The chi-square or Fisher exact tests of association were used to compare categorical characteristics. RESULTS: Two hundred and thirty-three MRI-detected breast lesions were included in the study, which consisted of 171 masses, 7 enhancing foci, and 55 NME lesions. Of all lesions, 52% (89/171) of masses, 29% (16/55) of areas of NME, and 29% (2/7) of foci were seen on US. Moreover, 43 per 63 (68%) of malignant, 18 per 47 (38%) of high-risk and 46 per 123 (37%) of benign lesions were seen on MRI-directed US. Of the invasive malignant lesions, 77% (36/47) had a sonographic correlate. For masses, the average size on MRI was 1.1 cm, and MRI size had a statistically significant association with US visibility (P value 0.01). Similarly, spiculated margins on MRI for masses had a significant association with US visibility (P value 0.0006). Linear, segmental, and regional distributions of areas of NME were associated with decreased likelihood of sonographic visibility (P = 0.049). CONCLUSION: MRI-directed US is a useful tool in the management of MRI-detected breast lesions. Our study indicates that masses, particularly those with spiculated margins on MRI, should be sent to US for further assessment. Additionally, masses are more likely to be seen under US as their size increases. MRI-directed US is less likely to visualize areas of NME and enhancing foci, which may be managed with MRI follow-up or MRI-guided biopsy depending on their level of suspicion.

Establishing Normal Testicular 18F-FDG PET/CT SUVs.

OBJECTIVE. Knowledge of normal testicular 18F-FDG PET/CT (FDG PET/CT) SUVs is crucial for accurate examination interpretation. The objective of this study was to establish normal testicular SUV ranges among adult men receiving health care in North America. MATERIALS AND METHODS. A retrospective review of an institutional electronic database identified adult men undergoing pretreatment clinical FDG PET/CT examinations from March 15, 2013, through March 15, 2018. An FDG PET/CT image review of 700 testicles in 350 male patients was performed. Data collected included testicular SUVmax, SUVmean, and visual PET pattern of uptake. RESULTS. Testicular SUVmean and SUVmax values (mean ± SD) by age group were as follows: 3.1 ± 0.7 and 3.8 ± 0.9 for the age group of 18-30 years; 3.2 ± 0.6 and 4.0 ± 0.8, 31-40 years; 3.1 ± 0.4 and 3.8 ± 0.5, 41-50 years; 3.0 ± 0.5 and 3.7 ± 0.7, 51-60 years; 2.9 ± 0.5 and 3.5 ± 0.7, 61-70 years; 2.8 ± 0.5 and 3.5 ± 0.7, 71-80 years; and 2.6 ± 0.5 and 3.3 ± 0.6, more than 80 years. A statistically significant difference exists between age groups for testicular SUVmean (p ≤ .001) and SUVmax (p < .001), with SUVs peaking in the 4th decade of life and subsequently declining with age. A small but significant negative correlation exists between blood glucose level and testicular SUVmean (r = -0.12). CONCLUSION. This study reports the largest currently known cohort of SUVs in normal testicles and may guide clinical interpretation of testicular FDG activity. Discrepancies in normal SUVs may exist because of differences in patient demographics and PET technology.

Bargain Hunting for Buffered Lidocaine: A Collaborative Discovery of Cost-saving Strategies That Can Improve Patient Care.

Buffered lidocaine is a local anesthetic option during percutaneous needle-directed procedures in the breast. At our institution, sodium bicarbonate (the buffer) is dispensed in volumes that frequently lead to medical waste and shortages. In this study, we describe how moving the buffering of lidocaine from the procedure room to our clinical hospital pharmacy results in a reduction in costs and improves satisfaction across the breast radiology department. While cost savings are difficult to tease out in practices that opt for bundled payments, we were able to access pricing and supply data and coordinate with our pharmacy to change our practice. Making these changes saves our practice $26 000 a year and allows us to continue to offer buffered lidocaine even during sodium bicarbonate shortages. This manuscript describes how these changes came about and their economic impact.

Outcomes of solitary dilated breast ducts in symptomatic and asymptomatic patients.

OBJECTIVE: The purpose of this study is to assess the outcomes of symptomatic and asymptomatic solitary dilated ducts detected on mammography, ultrasound, and MRI. METHODS: All cases of isolated solitary dilated ducts between January 1, 2009 and December 31, 2016 in non-lactating females were reviewed. Clinical data, including patient's age, breast cancer history, and pathology results were collected. Imaging was reviewed, and indication for the exam, breast density, maximum diameter of the dilated duct on ultrasound, presence of an intraductal mass, presence of intraductal vascularity, presence of intraductal echogenicity, and subareolar or peripheral location of the dilated duct were recorded. RESULTS: 87 cases of solitary dilated ducts were assessed in this study, of which 3 were malignant, resulting in a positive predictive value of 3.5% (3/87). No malignancy was identified in asymptomatic screening patients. The three malignant cases were seen in patients presenting with a palpable lump (n = 1) or bloody nipple discharge (n = 2). There was a statistically significant association observed between the dilated duct diameter (p = 0.049) and presence of intraductal vascularity (p = 0.0005) with presence of malignancy. CONCLUSION: Rate of malignancy is low in solitary dilated ducts, especially among asymptomatic patients. Patient's presenting with clinical symptoms, larger dilated duct diameters, and/or intraductal vascularity may require additional evaluation including biopsy to exclude malignancy. ADVANCES IN KNOWLEDGE: Clinical and imaging factors can assist in better identifying patients with solitary dilated ducts who should undergo biopsy.

Tomosynthesis-Guided Needle Localization of Breast and Axillary Lesions: Our Initial Experience.

OBJECTIVE: The purpose of this study is to review tomosynthesis-guided wire and seed needle localizations of the breast and axilla performed at our institution. CONCLUSION: Tomosynthesis-guided needle localizations were performed for 38 lesions, including 14 architectural distortions, five groups of calcifications, two focal asymmetries, three masses, four breast clips, and 10 axillary clips. All lesions were successfully removed at surgery, indicating that breast and axillary lesions can be precisely localized under tomosynthesis.

Impact of Low-Dose Computed Tomography on Computed Tomography Orders and Scan Length.

Background: New techniques have reduced the radiation dose delivered from a computed tomography (CT) examination. These techniques do not affect the number of scans ordered, the number of phases in each examination, or the scan length, as these parameters are controlled by ordering providers and CT technologists. The purpose of this study was to determine if deploying low-dose CT resulted in an increase in radiation exposure because of more liberal ordering habits or more liberal scanning ranges. Methods: We identified the most frequent CT examination types through a retrospective study of billing data from 2013. A campaign for low-dose CT scans was implemented, and data from 2 months prior and 2 months after were collected (n=797; average age=51.0 years ± 20.5; range, 4 to 97 years) and analyzed for differences in radiation dose, overall area scanned, and number of phases requested using unpaired t tests. Results: According to the billing data, the largest category of CT scans was the abdominal CT (31% of all CT examinations). After the low-dose campaign was implemented, we observed no difference in the number of examination phases ordered (1.2 ± 0.5 vs 1.3 ± 0.6, P=0.15), no increase in length of the scan (45.1 ± 7.5 cm vs 43.7 ± 10. 4 cm, P=0.08), and an overall decrease in dose (1,069 ± 634 mGy*cm vs 676 ± 480 mGy*cm, P<0.001). Conclusion: A campaign alerting staff to the availability of low-dose CT did not cause an increase in CT examination ordering and did not impact the area scanned by technologists.

Can MRI contribute to pulmonary nodule analysis?

BACKGROUND: There is no accurate method distinguishing different types of pulmonary nodules. PURPOSE: To investigate whether multiparametric 3T MRI biomarkers can distinguish malignant from benign pulmonary nodules, differentiate different types of neoplasms, and compare MRI-derived measurements with values from commonly used noninvasive imaging modalities. STUDY TYPE: Prospective. SUBJECTS: Sixty-eight adults with pulmonary nodules undergoing resection. SEQUENCES: Respiratory triggered diffusion-weighted imaging (DWI), periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) fat saturated T2 -weighted imaging, T1 -weighted 3D volumetric interpolated breath-hold examination (VIBE) using CAIPIRINHA (controlled aliasing in parallel imaging results in a higher acceleration). ASSESSMENT/STATISTICS: Apparent diffusion coefficient (ADC), T1 , T2 , T1 and T2 normalized to muscle (T1 /M and T2 /M), and dynamic contrast enhancement (DCE) values were compared with histology to determine whether they could distinguish malignant from benign nodules and discern primary from secondary malignancies using logistic regression. Predictability of primary neoplasm types was assessed using two-sample t-tests. MRI values were compared with positron emission tomography / computed tomography (PET/CT) to examine if they correlated with standardized uptake value (SUV) or CT Hounsfield unit (HU). Intra- and interreader agreements were assessed using intraclass correlations. RESULTS: Forty-nine of 74 nodules were malignant. There was a significant association between ADC and malignancy (odds ratio 4.47, P < 0.05). ADC ≥1.3 µm2 /ms predicted malignancy. ADC, T1 , and T2 together predicted malignancy (P = 0.003). No MRI parameter distinguished primary from metastatic neoplasms. T2 predicted PET positivity (P = 0.016). T2 and T1 /M correlated with SUV (P < 0.05). Of 18 PET-negative malignant nodules, 12 (67%) had an ADC ≥1.3 µm2 /ms. With the exception of T2 , all noncontrast MRI parameters distinguished adenocarcinomas from carcinoid tumors (P < 0.05). T1 , T2 , T1 /M, and T2 /M correlated with HU and therefore can predict nodule density. Combined with ADC, washout enhancement, arrival time (AT), peak enhancement intensity (PEI), Ktrans , Kep , Ve collectively were predictive of malignancy (P = 0.012). Combined washin, washout, time to peak (TTP), AT, and PEI values predicted malignancy (P = 0.043). There was good observer agreement for most noncontrast MRI biomarkers. DATA CONCLUSION: MRI can contribute to pulmonary nodule analysis. Multiparametric MRI might be better than individual MRI biomarkers in pulmonary nodule risk stratification. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.