Imaging of Biliary Tree Abnormalities.

Pathologic conditions of the biliary system, although common, can be difficult to diagnose clinically. Challenges in biliary imaging include anatomic variants and the dynamic nature of the biliary tract, which can change with age and intervention, blurring the boundaries of normal and abnormal. Choledochal cysts can have numerous appearances and are important to diagnose given the risk of cholangiocarcinoma potentially requiring surgical resection. Choledocholithiasis, the most common cause of biliary dilatation, can be difficult to detect at US and CT, with MRI having the highest sensitivity. However, knowledge of the imaging pitfalls of MRI and MR cholangiopancreatography is crucial to avoid misinterpretation. Newer concepts in biliary tract malignancy include intraductal papillary biliary neoplasms that may develop into cholangiocarcinoma. New paradigms in the classification of cholangiocarcinoma correspond to the wide range of imaging appearances of the disease and have implications for prognosis. Accurately staging cholangiocarcinoma is imperative, given expanding curative options including transplant and more aggressive surgical options. Infections of the biliary tree include acute cholangitis or recurrent pyogenic cholangitis, characterized by obstruction, strictures, and central biliary dilatation. Inflammatory conditions include primary sclerosing cholangitis, which features strictures and fibrosis but can be difficult to differentiate from secondary causes of sclerosing cholangitis, including more recently described entities such as immunoglobulin G4-related sclerosing cholangitis and COVID-19 secondary sclerosing cholangitis. The authors describe a wide variety of benign and malignant biliary tract abnormalities, highlight differentiating features of the cholangitides, provide an approach to interpretation based on the pattern of imaging findings, and discuss pearls and pitfalls of imaging to facilitate accurate diagnosis. ©RSNA, 2024 Supplemental material is available for this article.

Pancreatic Cancer and Its Mimics.

Pancreatic ductal adenocarcinoma (PDAC) is the most common primary pancreatic malignancy, ranking fourth in cancer-related mortality in the United States. Typically, PDAC appears on images as a hypovascular mass with upstream pancreatic duct dilatation and abrupt duct cutoff, distal pancreatic atrophy, and vascular encasement, with metastatic involvement including lymphadenopathy. However, atypical manifestations that may limit detection of the underlying PDAC may also occur. Atypical PDAC features include findings related to associated conditions such as acute or chronic pancreatitis, a mass that is isointense to the parenchyma, multiplicity, diffuse tumor infiltration, associated calcifications, and cystic components. Several neoplastic and inflammatory conditions can mimic PDAC, such as paraduodenal "groove" pancreatitis, autoimmune pancreatitis, focal acute and chronic pancreatitis, neuroendocrine tumors, solid pseudopapillary neoplasms, metastases, and lymphoma. Differentiation of these conditions from PDAC can be challenging due to overlapping CT and MRI features; however, certain findings can help in differentiation. Diffusion-weighted MRI can be helpful but also can be nonspecific. Accurate diagnosis is pivotal for guiding therapeutic planning and potential outcomes in PDAC and avoiding biopsy or surgical treatment of some of these mimics. Biopsy may still be required for diagnosis in some cases. The authors describe the typical and atypical imaging findings of PDAC and features that may help to differentiate PDAC from its mimics. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Zins in this issue.

Gallbladder Carcinoma and Its Differential Diagnosis at MRI: What Radiologists Should Know.

Gallbladder carcinoma is the most common cancer of the biliary system. It is challenging to diagnose because patients are often asymptomatic or present with nonspecific symptoms that mimic common benign diseases. Surgical excision is the only curative therapy and is best accomplished at early non-locally advanced stages. Unfortunately, gallbladder cancer often manifests at late locally advanced stages, precluding cure. Early tumors are often incidentally detected at imaging or at cholecystectomy performed for another indication. Typical imaging features of localized disease include asymmetric gallbladder wall thickening, polyps larger than 1.0 cm, and a solid mass replacing the gallbladder lumen. Advanced tumors are often infiltrative and can be confusing at CT and MRI owing to their large size. Determination of the origin of the lesion is paramount to narrow the differential diagnosis but is often challenging. It is important to identify gallbladder cancer and distinguish it from other benign and malignant hepatobiliary processes. Since surgical resection is the only curative treatment option, radiologist understanding and interpretation of pathways of nodal and infiltrative tumor spread can direct surgery or preclude patients who may not benefit from surgery. While both CT and MRI are effective, MRI provides superior soft-tissue characterization of the gallbladder and biliary tree and is a useful imaging tool for diagnosis, staging, and evaluation of treatment response. ©RSNA, 2020.

A 73-gene proliferative transcriptomic signature predicts uterine serous carcinoma patient survival and response to primary therapy.

OBJECTIVES: To develop a transcriptomic signature capable of predicting overall survival (OS) for uterine serous carcinoma (USC). METHODS: RNAseq data for 58 USC patients were obtained from TCGA. Expression of 73 candidate genes was measured for 67 Augusta University (AU) samples using NanoString technology. RESULTS: Analysis of the TCGA RNAseq data identified 73 genes that individually predict prognosis for USC patients and an elastic net model with all 73 genes (USC73) distinguishes a good OS group with low USC73 score from a poor OS group with high USC73 score (5-year OS = 83.3% and 13.3% respectively, HR = 40.1; p = 3 × 10-8). This finding was validated in the independent AU cohort (HR = 4.3; p = 0.0004). The poor prognosis group with high USC73 score consists of 37.9% and 32.8% of patients in the TCGA and AU cohort respectively. USC73 score and pathologic stage independently contribute to OS and together provide the best prognostic value. Early stage, low USC73 patients have the best prognosis (5-year OS = 85.1% in the combined dataset), while advanced stage, high USC73 patients have the worst prognosis (5-year OS = 6.4%, HR = 30.5, p = 1.2 × 10-12). Consistent with the observed poor survival, primary cell cultures from high USC73 patients had higher proliferation rate and cell cycle progression; and high USC73 patients had lower rates of complete response to standard therapy. CONCLUSIONS: The USC73 transcriptomic signature and stage independently predict OS of USC patients and the best prediction is achieved using USC73 and stage. USC73 may also serve as a therapeutic biomarker to guide patient care.

Multidetector CT Findings in the Abdomen and Pelvis after Damage Control Surgery for Acute Traumatic Injuries.

After experiencing blunt or penetrating trauma, patients in unstable condition who are more likely to die of uncorrected shock than of incomplete injury repairs undergo emergency limited exploratory laparotomy, which is also known as damage control surgery (DCS). This surgery is part of a series of resuscitation steps, with the goal of stabilizing the patient's condition, with rapid surgical control of hemorrhage followed by supportive measures in the intensive care unit before definitive repair of injuries. These patients often are imaged with multidetector CT within 24-48 hours of the initial surgery. Knowledge of this treatment plan is critical to CT interpretation, because there are anatomic derangements and foreign bodies that would not be present in patients undergoing surgery for other reasons. Patients may have injuries beyond the surgical field that are only identified at imaging, which can alter the care plan. Abnormalities related to the resuscitation period such as the CT hypoperfusion complex and ongoing hemorrhage can be recognized at CT. Familiarity with these imaging and clinical findings is important, because they can be seen not only in trauma patients after DCS but also in other patients in the critical care setting. The interpretation of imaging studies can be helped by an understanding of the diagnostic challenges of grading organ injuries with surgical materials in place and the awareness of potential artifacts on images in these patients. Online supplemental material is available for this article. ©RSNA, 2019 See discussion on this article by LeBedis .

Uncommon Intraluminal Tumors of the Gallbladder and Biliary Tract: Spectrum of Imaging Appearances.

Intraluminal pathologic conditions of the bile ducts and gallbladder are common, most frequently consisting of calculi and adenocarcinoma. In recent years, intraductal papillary neoplasm of the bile ducts (IPN-B), which is analogous to intraductal papillary mucinous neoplasm of the pancreas, has been recognized as a distinct pathologic entity and a precursor lesion to adenocarcinoma of the bile ducts. Intraductal tubulopapillary neoplasm (ITPN) of the bile duct was subsequently described as a distinct pathologic entity. With increased awareness and advances in imaging techniques, these lesions are diagnosed with increased frequency at preoperative imaging. A similar neoplasm in the gallbladder is referred to as intracholecystic papillary neoplasm. These lesions are often diagnosed at a preinvasive stage and have a better prognosis than invasive cholangiocarcinoma when treated with curative resection, underscoring the importance of an accurate imaging diagnosis. The most common causes of polypoid lesions of the gallbladder are cholesterol polyps and adenomyomatosis. These lesions need to be differentiated from the less common but clinically important adenocarcinoma of the gallbladder. Imaging is crucial to identify polyps that are at high risk for malignancy so that the appropriate management choice between imaging follow-up and cholecystectomy can be made by the treating physicians. Other less common gallbladder tumors, such as gallbladder adenomas, lymphoma, and metastases to the gallbladder, can manifest as intraluminal tumors; and awareness of these lesions is also important. In this article, the recent literature is reviewed; and the imaging appearances, histopathologic findings, and management of uncommon intraluminal tumors of the bile ducts and gallbladder and their mimics are discussed. ©RSNA, 2019.

Secondary Hypertension and Complications: Diagnosis and Role of Imaging.

Hypertension is a common problem; if left untreated, it can result in significant complications, including those involving the cardiovascular system and end organs. Approximately 10% of patients with hypertension are classified as having secondary hypertension, defined as hypertension attributable to a specific and potentially remediable cause. The evaluation for secondary hypertension typically begins with acquiring the patient history and performing a physical examination and screening laboratory tests. Directed imaging may be performed, on the basis of laboratory test results, to assess for potential causes of secondary hypertension. The causes can be broadly classified as endocrine (eg, hyperaldosteronism, pheochromocytoma, hyperparathyroidism) and nonendocrine (eg, aortic coarctation, renal vascular hypertension). In addition, patients with hypertension can develop significant complications that also are diagnosed with imaging, including conditions involving the cardiovascular system (eg, aortic aneurysm, acute aortic syndrome) and central nervous system (eg, stroke, subarachnoid hemorrhage, and posterior reversible encephalopathy syndrome). The imaging workup and imaging appearances of some of the causes of secondary hypertension are reviewed, treatment options are discussed, and the imaging appearances of hypertension-related complications are described. It is important for radiologists to accurately diagnose the secondary causes of hypertension, as many of them are treatable, and treatment may result in improved symptoms or resolution of hypertension. ©RSNA, 2019.

Notice of Withdrawal: No Incidence of Nephrogenic Systemic Fibrosis after Gadobenate Dimeglumine Administration in Patients Undergoing Dialysis or Those with Severe Chronic Kidney Disease.

The authors have requested to withdraw this manuscript from publication because the study was not conducted in full accordance with the relevant institutional IRB protocol. © RSNA, 2018.

Spectrum of Extratesticular and Testicular Pathologic Conditions at Scrotal MR Imaging.

Diagnostic workup of scrotal lesions should begin with a complete clinical history and physical examination, including analysis of risk factors such as family history of testicular cancer, personal history of tumor in the contralateral testis, and cryptorchidism, followed by imaging. Scrotal ultrasonography (US) with a combination of gray-scale and color Doppler techniques has been the first-line imaging modality for evaluation of testicular and extratesticular lesions because of its low cost, wide availability, and high diagnostic accuracy. However, US has limitations related to operator dependence, the relatively small field of view, and lack of tissue characterization. Magnetic resonance (MR) imaging, because of its superior soft-tissue contrast and multiplanar capabilities, is increasingly being used as a supplemental diagnostic problem-solving tool in cases where scrotal US findings are inconclusive or nondiagnostic. In addition to morphology, lesion location, and tissue characterization (eg, fat, blood products, granulation tissue, and fibrosis), scrotal MR imaging provides important information that can affect surgical planning and improve patient care. MR imaging also is helpful for differentiating testicular and extratesticular lesions, distinguishing between benign and malignant lesions, and evaluating the local extent of disease. This review discusses the anatomy and MR imaging features of testicular and extratesticular neoplastic and nonneoplastic conditions and describes relevant MR imaging techniques. ©RSNA, 2018 Contact information that appeared in the print version of this article was updated in the online version on May 14, 2018.

Pulmonary Function Tests for the Radiologist.

Pulmonary function tests (PFTs) provide important quantitative information about lung function and can be used to elucidate pathologic conditions responsible for respiratory symptoms, assess the severity and course of disease, and evaluate the patient for suitability and timing for lung transplantation. They are typically used in tandem with chest imaging, along with other ancillary data, to arrive at a specific diagnosis. PFTs may provide the radiologist with clues to the diagnosis and grading of a wide variety of pulmonary diseases. In this review, the authors discuss the clinical use of PFTs, their major components, and important measurements and graphical representations that are essential for understanding and interpreting the results. The key components of PFT panels-static lung volumes, dynamic lung function (spirometry), and diffusion capacity-are explained. The authors present a general algorithmic approach for problem solving, with recognition of common patterns of results (obstructive, restrictive, mixed, nonspecific, and normal). Pulmonary diseases from each of the major patterns and chest imaging are illustrated, and correlations between particular PFT results and disease severity and morphology at imaging are examined. Common pitfalls encountered during interpretation are also highlighted. A basic understanding of the mechanics of PFTs, characteristic patterns in important diseases, and correlation between lung function and imaging findings may assist the radiologist in diagnosis and follow-up of key pulmonary diseases and strengthen the radiologist's role as part of a multidisciplinary diagnostic team. Online supplemental material is available for this article. ©RSNA, 2017.

Role of Imaging in the Evaluation of Male Infertility.

Infertility is defined herein as the inability to achieve pregnancy after frequently engaging in unprotected sexual intercourse for 1 year. Among infertile couples, the cause of infertility involves the male partner in approximately 50% of cases. Male infertility is usually caused by conditions affecting sperm production, sperm function, or both, or blockages that prevent the delivery of sperm. Chronic health problems, injuries, lifestyle choices, anatomic problems, hormonal imbalances, and genetic defects can have a role in male infertility. The diagnostic workup of male infertility should include a thorough medical and reproductive history, physical examination, and semen analysis, followed by imaging. The main role of imaging is identification of the causes of infertility, such as congenital anomalies and disorders that obstruct sperm transport and may be correctable. Scrotal ultrasonography is the most common initially performed noninvasive examination used to image the male reproductive system, including the testes and extratesticular structures such as the epididymis. Magnetic resonance (MR) imaging is another noninvasive imaging modality used in the pelvis to evaluate possible obstructive lesions involving the ductal system. MR imaging of the brain is extremely useful for evaluating relevant neurologic abnormalities, such as pituitary gland disorders, that are suspected on the basis of hormone analysis results. Invasive techniques are usually reserved for therapeutic interventions in patients with known abnormalities. In this article, the causes and imaging findings of obstructive and nonobstructive azoospermia are discussed. In addition to detecting treatable conditions that are related to male infertility, identifying the life-threatening entities associated with infertility and the genetic conditions that could be transmitted to offspring-especially in patients who undergo assisted reproduction-is critical. ©RSNA, 2017.

Safety and Quality of 1.5-T MRI in Patients With Conventional and MRI-Conditional Cardiac Implantable Electronic Devices After Implementation of a Standardized Protocol.

OBJECTIVE: The purpose of this study was to evaluate the safety and diagnostic utility of 1.5-T MRI examinations of individuals with conventional and MRI-conditional cardiac implantable electronic devices (CIEDs). SUBJECTS AND METHODS: Patients with a CIED who were referred for MRI were evaluated by radiologists and cardiac electrophysiologists for study participation. CIED interrogation was performed immediately before and after MRI, and cardiac telemetry monitoring was performed during MRI. CIED programming changes, malfunctions, and intraprocedural events were documented. Whether diagnostic questions were answered and whether artifacts related to the CIED were present and negatively affected image interpretation were recorded. RESULTS: One hundred thirteen MRI examinations were performed for 104 patients with CIEDs (74 pacemakers [60 conventional, 14 MRI conditional]; 39 implantable cardiac defibrillators). Device reprogramming was required before MRI for 62.8% of studies (71/113). No significant changes in lead parameters were noted during or after MRI. Electromagnetic noise was detected on at least one lead in 7.1% of studies. Three patients reported transient symptoms (one case each of heating at the pocket site, tingling at the pocket site, and palpitations). All images were considered diagnostic for the original clinical query. Artifacts related to CIEDs were described in 3.5% of MRI reports (4/113) and were present only when the pulse generator was included in the FOV. CIED-related artifacts limited evaluation of tissues immediately adjacent to the pulse generator. CONCLUSION: Establishment of a multidisciplinary work flow allows individuals with conventional and MRI-conditional CIEDs to safely undergo 1.5-T MRI with diagnostic questions consistently answered.

Hematospermia Evaluation at MR Imaging.

Hematospermia is a challenging and anxiety-provoking condition that can manifest as a single episode or recur over the course of weeks to months. It is usually a benign self-limiting condition in younger sexually active males without a history of risk factors such as cancer, urogenital malformations, bleeding disorders, and their associated symptoms. However, patients with recurrent, refractory and painful hematospermia with associated symptoms, such as fever, pain, or weight loss, require evaluation through clinical assessment and noninvasive investigations to rule out underlying pathologic conditions such as ejaculatory obstruction, infectious and inflammatory causes, malignancy, vascular malformations, and systemic disorders that increase the risk of bleeding, especially when presenting in older men. If these investigations are negative, the patient should be reassured and treated accordingly. In the recent past, magnetic resonance (MR) imaging has assumed a major role in the investigation of hematospermia due to its excellent soft-tissue contrast and multiplanar capabilities. In this review, we will discuss the potential causes of hematospermia and its diagnostic workup, including pathophysiology, anatomic considerations, the imaging appearance of associated pathologic conditions, and management. (©)RSNA, 2016.

Immediate post-doxorubicin drug-eluting beads chemoembolization Mr Apparent diffusion coefficient quantification predicts response in unresectable hepatocellular carcinoma: A pilot study.

PURPOSE: To investigate magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) of hepatocellular carcinoma (HCC) immediately post-doxorubicin drug-eluting beads transcatheter arterial chemoembolization (DEB-TACE) therapy as an early imaging biomarker of therapy response. MATERIALS AND METHODS: In a single-center prospective correlative study, 12 consecutive patients, median age 64 years, underwent DEB-TACE and dynamic contrast-enhanced (DCE) and DWI (b = 50,400,800 s/mm(2)) MRI at baseline with respect to first DEB-TACE, within 3 hours, and at 1 and 3 months posttherapy. DCE imaging response was evaluated according to target mRECIST and EASL. Relative change (RC) in apparent diffusion coefficient (ADC) of treated lesions was measured on follow-ups. Correlation between ADC RC in tumors and anatomical response were evaluated with paired t-test and receiver operator characteristic (ROC) curve. Survival from first DEB-TACE was estimated using Kaplan-Meier and log-rank analysis. RESULTS: Compared to baseline, mean ADC increased significantly for responders within 3 hours post-DEB-TACE (0.73 ± 0.20 mm(2) /s vs. 0.99 ± 0.28 mm(2) /s × 10(-3) (P = 0.001)). There was no significant change in ADC within 3 hours for nonresponders. ADC RC threshold of 20% immediately post-DEB-TACE showed 100% sensitivity and specificity in predicting anatomical response at 1 and 3 months with patients with ≥20% ADC increase demonstrated significantly prolonged mean overall survival compared to others (25.4 vs. 13.3 months (P = 0.017)). CONCLUSION: ADC relative change of ≥20% immediately post-DEB-TACE is an accurate predictor of objective and quantitative treatment response and prolonged survival in unresectable HCC.

Baseline and Early MR Apparent Diffusion Coefficient Quantification as a Predictor of Response of Unresectable Hepatocellular Carcinoma to Doxorubicin Drug-Eluting Bead Chemoembolization.

PURPOSE: To investigate baseline and early apparent diffusion coefficients (ADC) derived from diffusion-weighted imaging (DWI) as a predictor of objective response (OR) and survival in unresectable hepatocellular carcinoma (HCC) treated with doxorubicin drug-eluting bead (DEB) transcatheter arterial chemoembolization. MATERIALS AND METHODS: In a prospective study, 57 patients underwent DEB chemoembolization. Dynamic contrast-enhanced magnetic resonance imaging and DWI were performed at baseline and 1 and 3 months after DEB chemoembolization. OR was evaluated per modified Response Evaluation Criteria In Solid Tumors (mRECIST) and European Association for the Study of the Liver (EASL) guidelines. Baseline ADCs of tumors that showed OR at 1 and 3 months were compared with nonresponding tumor ADCs by two-sample t test and receiver operating characteristic curves. Additionally, ADC changes at 30 days were correlated with OR. Finally, Kaplan­Meier analysis was used to compare survival between patients with lesions demonstrating more restricted baseline diffusion and others. RESULTS: At 1 month, 33 patients (60%) showed OR (21 complete responses and 12 partial responses). At baseline, tumors with OR at 1 month showed significantly more restricted diffusion (0.731 × 10(−3) mm2/s) compared with others (1.057 × 10(−3) mm2/s; P = .031). No difference between response rates at 1 and 3 months according to mRECIST and EASL was observed. For an area under the curve of 0.965, the sensitivity and specificity of predicting objective tumor response at 1 month using a baseline HCC ADC of 0.83 × 10(−3) mm2/s were 91% and 96%, respectively. In addition, patients with lesions with a baseline ADC < 0.83 × 10(−3) mm2/s showed prolonged survival compared with others (P < .001). CONCLUSIONS: In unresectable HCC, a baseline ADC < 0.83 × 10(−3) mm2/s is a predictor of survival and treatment response at 1 and 3 months after DEB chemoembolization with high sensitivity and specificity.

R.E.N.A.L. (Radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines) nephrometry score predicts early tumor recurrence and complications after percutaneous ablative therapies for renal cell carcinoma: a 5-year experience.

PURPOSE: To investigate the prognostic value of R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines) nephrometry score after percutaneous ablation of renal cell carcinoma (RCC). MATERIALS AND METHODS: A retrospective 5-year study was performed. Participants were 87 consecutive patients (median age, 67.1 y; 59.7% male, 40.3% female) with 101 biopsy-proven RCCs who underwent percutaneous ablation (54.0% cryoablation, 46.0% radiofrequency ablation). Follow-up computed tomography or magnetic resonance imaging was performed in all cases (mean follow-up, 34.6 mo ± 23.5). R.E.N.A.L. scores were analyzed to determine the association of the score with treatment outcomes and complications. RESULTS: All tumors corresponded to stage 1A disease. Mean tumor size was 2.05 cm (range, 0.7-3.9 cm), and 50.5% of the lesions measured > 2 cm. Nephrometry score was > 8 in 31.4% of lesions. Overall recurrence rate was 16.8%, first-year recurrence rate was 7.9%, and complication rate was 9.9%. A nephrometry score > 8 was associated with increased complications after percutaneous ablation (P < .0001), increased overall recurrence (P < .0001), and increased risk of first-year recurrence (P < .0001). Immediate complications were associated with tumor size > 2 cm (P < .0001) and risk of local recurrence (P < .001). Age, gender, and percutaneous ablation technique were not correlated with recurrence or immediate complications. Patients undergoing cryoablation had a higher nephrometry score with no significant differences in recurrence rate compared with RF ablation (P = .199). CONCLUSIONS: A R.E.N.A.L. nephrometry score ≥ 8 predicts recurrence and complications after percutaneous renal ablation.

Nonvascular post-liver transplantation complications: from US screening to cross-sectional and interventional imaging.

Orthotopic liver transplantation is becoming an increasingly routine procedure for a variety of benign and malignant diseases of the liver and biliary system. Continued improvements in surgical techniques and post-transplantation immunosuppression regimens have resulted in better graft and patient survival. A number of potentially treatable nonvascular complications of liver transplantation are visible at imaging, and accurate diagnosis of these complications allows patients to benefit from potential treatment options. Biliary complications include stricture (anastomotic and nonanastomotic), leak, biloma formation, and development of intraductal stones. Pathologic conditions, including hepatitis C infection, hepatocellular carcinoma, hepatic steatosis, and primary sclerosing cholangitis, may recur after liver transplantation. Transplant patients are at increased risk for developing de novo malignancy, including post-transplantation lymphoproliferative disorder, which results from immunosuppression. Patients are also at increased risk for systemic infection from immunosuppression, and patients with hepatic artery and biliary complications are at increased risk for liver abscess. Transplant recipients are typically followed with serial liver function testing; abnormal serum liver function test results may be the first indication that there is a problem with the transplanted liver. Ultrasonography is typically the first imaging test performed to try to identify the cause of abnormal liver function test results. Computed tomography, magnetic resonance imaging, angiography, and/or cholangiography may be necessary for further evaluation. Accurately diagnosing nonvascular complications of liver transplantation that are visible at imaging is critically important for patients to benefit from appropriate treatment.

Testicular tumors: what radiologists need to know--differential diagnosis, staging, and management.

Cryptorchidism, family history, and infertility are risk factors for testicular cancer. Most testicular cancers occur in young men aged 18-35 years, and seminoma is the most common cell type. Testicular tumors are usually diagnosed at ultrasonography (US) and are staged at computed tomography (CT) or magnetic resonance (MR) imaging. At US, testicular tumors usually appear as a solid intratesticular mass. Because the differential diagnosis includes infarct and infection, correlation with patient history and symptoms is important. At staging CT or MR imaging, retroperitoneal lymph nodes are considered regional lymph nodes, and the greatest nodal diameter is used to distinguish among N1-N3 disease. The right testicular vein drains into the inferior vena cava, and the left testicular vein drains into the left renal vein. Because of venous and lymphatic drainage pathways, retroperitoneal lymph nodes are the initial landing station for testicular cancers. Enlarged lymph nodes in the supraclavicular region, chest, and pelvis are considered distant metastases. Testicular cancer is initially treated with orchiectomy. The patient may then undergo active surveillance, chemotherapy, radiation therapy, or retroperitoneal lymph node resection, depending primarily on the clinical stage. Radiologists play an important role in initial diagnosis, staging, and imaging surveillance of testicular malignancies.

Case report: MR imaging features of disseminated uterine leiomyosarcoma presenting after hysterectomy with morcellation.

A 53-year-old woman underwent elective hysterectomy for symptomatic anemia secondary to abnormal uterine bleeding. She presented 15 months later with complaints of abdominal fullness. Abdominopelvic magnetic resonance imaging demonstrated multiple confluent enhancing solid masses centered in the pelvis and extending cranially to the level of the umbilicus. Additional separate nodules also were visible along the peritoneum. Biopsy demonstrated leiomyosarcoma. Additional clinical information was obtained, which revealed that the patient's prior hysterectomy was performed with morcellation. In November 2014, the United States Food and Drug Administration issued a warning discouraging the use of morcellation during hysterectomy and myomectomy because of the risk of seeding unsuspected malignancy. Radiologists should be aware of this potential complication of morcellation and its imaging appearance so that the correct diagnosis can be suggested in the imaging report.

Primary biliary tract malignancies: MRI spectrum and mimics with histopathological correlation.

Contrast-enhanced magnetic resonance imaging and magnetic resonance cholangiopancreatography (MRCP), due to their excellent soft tissue contrasts, have become first-line noninvasive tests in the characterization and detection of both hepatic and pancreaticobiliary pathologies. MRCP is also helpful in detecting the level and cause of obstruction in patients presenting with jaundice. Cholangiocarcinoma (CCA) is the most common primary malignant tumor arising from the bile duct epithelium, with extrahepatic tumors presenting more often than with intrahepatic ones. However, the diagnosis and management of CCA is made more complex by a variety of malignant and benign conditions that resemble CCA, including hepatocellular carcinoma variants such as the fibrolamellar variant of hepatocellular carcinoma, cholangiocellular carcinoma, biliary metastases, hepatic inflammatory pseudotumor, lymphoepithelioma-like carcinoma, confluent fibrosis, primary sclerosis cholangitis, and the secondary sclerosing cholangitis complex. Consequently, knowledge of the underlying risk factors and imaging characteristics of these conditions is important in differentiating between neoplastic and non-neoplastic conditions in order to reach a definite diagnosis. Endoscopic retrograde cholangiopancreatography should be reserved for those patients who require intervention or biopsy for histopathological diagnosis.