Acquired ductopenia: an insight into imaging findings.

Hepatic ductopenia is a pathologic diagnosis characterized by a decrease in the number of intrahepatic bile ducts as a consequence of various underlying etiologies. Some etiologies, such as primary sclerosing cholangitis, primary biliary cholangitis, and ischemic cholangitis, often have distinctive imaging findings. In contrast, other causes such as chronic rejection following liver transplantation, drug-induced biliary injury, infection, malignancy such as lymphoma, and graft-versus-host disease may only have ancillary or non-specific imaging findings. Thus, diagnosing ductopenia in conditions with nonspecific imaging findings requires a multidimensional approach, including clinical evaluation, serological testing, imaging, and liver histology to identify the underlying cause. These etiologies lead to impaired bile flow, resulting in cholestasis, liver dysfunction, and, ultimately, cirrhosis and liver failure if the underlying cause remains untreated or undetected. In the majority of instances, individuals diagnosed with ductopenia exhibit a positive response to treatment addressing the root cause or cessation of the causative agent. This article focuses on acquired causes of ductopenia, its clinical manifestation, histopathology, imaging diagnosis, and management.

3.0-T MR-guided transgluteal in-bore-targeted prostate biopsy under local anesthesia in patients without rectal access: a single-institute experience and review of literature.

PURPOSE: To describe the technique and evaluate the performance of MRI-guided transgluteal in-bore-targeted biopsy of the prostate gland under local anesthesia in patients without rectal access. METHODS: Ten men (mean age, 69 (range 57-86) years) without rectal access underwent 13 MRI-guided transgluteal in-bore-targeted biopsy of the prostate gland under local anesthesia. All patients underwent mp-MRI at our institute prior to biopsy. Three patients had prior US-guided transperineal biopsy which was unsuccessful in one, negative in one, and yielded GG1 (GS6) PCa in one. Procedure time, complications, histopathology result, and subsequent management were recorded. RESULTS: Median interval between rectal surgery and presentation with elevated PSA was 12.5 years (interquartile range (IQR) 25-75, 8-36.5 years). Mean PSA was 11.9 (range, 4.8 -59.0) ng/ml and PSA density was 0.49 (0.05 -3.2) ng/ml/ml. Distribution of PI-RADS v2.0/2.1 scores of the targeted lesions were PI-RADS 5-3; PI-RADS 4-6; and PI-RADS 3-1. Mean lesion size was 1.5 cm (range, 1.0-3.6 cm). Median interval between MRI and biopsy was 5.5 months (IQR 25-75, 1.5-9 months). Mean procedure time was 47.4 min (range, 29-80 min) and the number of cores varied between 3 and 5. Of the 13 biopsies, 4 yielded clinically significant prostate cancer (csPca), with a Gleason score ≥ 7, 1 yielded insignificant prostate cancer (Gleason score = 6), 7 yielded benign prostatic tissue, and one was technically unsuccessful. 3/13 biopsies were repeat biopsies which detected csPCa in 2 out of the 3 patients. None of the patients had biopsy-related complication. Biopsy result changed management to radiation therapy with ADT in 2 patients with the rest on active surveillance. CONCLUSION: MRI-guided transgluteal in-bore-targeted biopsy of the prostate gland under local anesthesia is feasible in patients without rectal access.

PET/MRI in colorectal and anal cancers: an update.

Positron emission tomography (PET) in the era of personalized medicine has a unique role in the management of oncological patients and offers several advantages over standard anatomical imaging. However, the role of molecular imaging in lower GI malignancies has historically been limited due to suboptimal anatomical evaluation on the accompanying CT, as well as significant physiological 18F-flurodeoxyglucose (FDG) uptake in the bowel. In the last decade, technological advancements have made whole-body FDG-PET/MRI a feasible alternative to PET/CT and MRI for lower GI malignancies. PET/MRI combines the advantages of molecular imaging with excellent soft tissue contrast resolution. Hence, it constitutes a unique opportunity to improve the imaging of these cancers. FDG-PET/MRI has a potential role in initial diagnosis, assessment of local treatment response, and evaluation for metastatic disease. In this article, we review the recent literature on FDG-PET/MRI for colorectal and anal cancers; provide an example whole-body FDG-PET/MRI protocol; highlight potential interpretive pitfalls; and provide recommendations on particular clinical scenarios in which FDG-PET/MRI is likely to be most beneficial for these cancer types.

Evaluating the Downstream Revenues of a Self-Pay Bi-Parametric Prostate MRI Program.

OBJECTIVE: To quantify downstream healthcare utilization and revenue associated with a self-pay bi-parametric prostate MRI (bpMRI) program. METHODS: Medical records of 592 patients who underwent bpMRI between August 2017 and March 2020 were examined for follow-up clinical activities. These include prostate biopsy, radical prostatectomy, external beam radiation therapy, brachytherapy, androgen deprivation therapy, CT Chest, Abdomen and Pelvis, PET/CT, MRI Pelvis, and Nuclear Medicine Bone Scans. The charges for each clinical activity were derived from the Medicare Physician Fee Schedule to conservatively estimate revenues. This patient population was further divided into four groups: Group A, patients who demonstrated an MRI lesion and underwent prostatectomy; Group B, patients who did not demonstrate lesion but underwent prostatectomy; Group C, patients who demonstrated lesion but did not undergo prostatectomy; and Group D, patients who neither demonstrated lesion nor underwent prostatectomy. Revenues for each group were categorized by Urology, Radiation Oncology and Radiology subspecialties. RESULTS: Conservative estimates yielded $520 of downstream revenue per patient who underwent bpMRI. Group A patients yielded 47% of total revenue ($1974 per patient). Group B patients, the smallest group, yielded $1828 per patient. Group C patients made up the largest group and grossed $398 per patient. Group D demonstrated the lowest per patient revenue of $179. Groups A and B yielded most relative revenue for Urology. Group C yielded most relative revenue for Radiation Oncology, and Group D yielded most relative revenue for Radiology. CONCLUSION: A self-pay bpMRI program has the potential to improve patient access to prostate cancer screening while remaining financial sustainable.

Pancreatic cystic neoplasms: a review of current recommendations for surveillance and management.

Pancreatic cystic neoplasms (PCN) comprise of a diverse array of pancreatic cysts, including intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), serous cystic neoplasms (SCN), cystic neuroendocrine tumors (cNET), and many others. Increasing use of cross-sectional imaging has resulted in greater numbers of PCNs discovered incidentally. The overall risk of malignancy is low, but can vary considerably between different classes of PCNs. Furthermore, many pancreatic cysts are indeterminate on imaging, and the inability to reliably predict the course of disease remains a challenge for radiologists. Due to the variability in disease course and a lack of high-quality studies on PCNs, there is no universal consensus when it comes to balancing optimal surveillance while avoiding the risk for overtreatment. Currently, there are three widely accepted international guidelines outlining guidelines for surveillance and management of PCNs: the American Gastroenterological Association (AGA) in 2015, the International Association of Pancreatology (IAP) last revised in 2017, and the European Study Group on Cystic Tumours of the Pancreas (European) last revised in 2018. In 2017, the American College of Radiology released its own comprehensive set of recommendations for managing indeterminate pancreatic cysts that are detected incidentally on CT or MRI. The purpose of this paper is to describe the key differences between the ACR recommendations and the aforementioned three sets of guidelines regarding cyst management, imaging surveillance, performance, and cost-effectiveness.

Extraprostatic extension in prostate cancer: primer for radiologists.

The presence of extraprostatic extension (EPE) on multiparametric MRI (mpMRI) is an important factor in determining the management of prostate cancer. EPE is an established risk factor for biochemical recurrence of prostate cancer after radical prostatectomy (RP) and patients with EPE may be considered for wider resection margins, non-nerve-sparing surgery, adjuvant radiation therapy (RT), or androgen deprivation therapy (ADT). Several statistical nomograms and scoring systems have been developed to predict pathological stage at time of RP but with varying accuracies. Using the current PI-RADS v2 mpMRI staging guidelines results in high specificity but lacks in sensitivity. These findings reveal the need for more standardization and further refinement of existing MRI protocols and prostate cancer prediction tools. Current studies have looked into indirect additional imaging criteria such as index tumor volume, length of capsular contact, and apparent diffusion coefficient. Measuring for these features can improve the robustness of mpMRI in staging prostate cancer, as they have been shown to be independent predictors of EPE. MRI/ultrasound fusion-guided targeted biopsy can detect EPE not found on standard biopsy. Collectively, these measurements and imaging techniques can augment the detection of EPE and subsequent risk stratification.

Neuroendocrine neoplasms of the genitourinary tract in adults: cross-sectional imaging spectrum.

Neuroendocrine (NE) neoplasms of the genitourinary (GU) tract in adults are rare tumors with distinct histopathology and variable biological behavior and imaging findings. They may be primary or metastatic in origin. The spectrum of primary GU tract NE neoplasms includes carcinoid, small cell carcinoma, large cell NE carcinoma, and paraganglioma. The tumors commonly show positivity to specific immunohistochemical markers and characteristic dense-core granules at the ultra-structural level. Although imaging findings are nonspecific and accurate differentiation from the more common malignancies of the individual organs is not possible, cross-sectional imaging modalities play an important role in the diagnosis, staging, and surveillance of these tumors. Somatostatin receptor scintigraphy (octreotide scan) may be useful in the detection and treatment of metastatic disease in select patients. Knowledge of the various NE tumors of the adult GU tract and familiarity with their pathological and imaging findings permit optimal patient management.

PET/MR Imaging in Cancers of the Gastrointestinal Tract.

PET/computed tomography (PET/CT) is an established hybrid imaging technique for staging and follow-up of gastrointestinal (GI) tract malignancies, especially for colorectal carcinoma. Dedicated hybrid PET/MR imaging scanners are currently available for clinical use. Although they will not replace regular use of PET/CT, they may have utility in selected cases of GI tract malignancies. The superior soft tissue contrast resolution and depiction of anatomy and the functional information obtained from diffusion-weighted imaging (DWI) provided by MR imaging in PET/MR imaging are advantages over CT of PET/CT for T staging and follow-up of rectal carcinoma and for better characterization of liver lesions. Functional information from DWI and use of liver-specific MR imaging contrast agents are an added advantage in follow-up of liver metastases after systemic and locoregional treatment. New radiotracers will improve the utility of PET/MR imaging in staging and follow-up of tumors, which may not be [18F]-2-fluoro-2-deoxy-d-glucose avid, such as hepatocellular carcinoma and neuroendocrine tumors. PET/MR imaging also has application in selected cases of cholangiocarcinoma, gallbladder cancer, and pancreatic carcinoma for initial staging and follow-up assessment.

Multiple Endocrine Neoplasia Syndromes: A Comprehensive Imaging Review.

MEN1, MEN2, and MEN4 comprise a series of familial disorders involving the simultaneous occurrence of tumors in more than one endocrine organ, collectively known as multiple endocrine neoplasia. Patients with this family of disorders develop tumors of the parathyroid gland, pancreas, pituitary gland, adrenal gland, and thyroid gland, along with miscellaneous neuroendocrine tumors of the respiratory and gastrointestinal tracts. Although some patients undergo early prophylactic surgical management, particularly in the setting of familial medullary thyroid carcinoma, many develop tumors later in life. These tumors are often discovered at imaging for screening purposes. Recognition of the imaging features of the known tumors is important for appropriate patient management.

Comparison of hybrid FDG PET/MRI compared with PET/CT in colorectal cancer staging and restaging: a pilot study.

PURPOSE: We report our initial clinical experience from a pilot study to compare the diagnostic accuracy of hybrid PET/MRI with PET/CT in colorectal cancer and discuss potential PET/MRI workflow solutions for colorectal cancer. METHODS: Patients underwent both FDG PET/CT and PET/MRI (Ingenuity TF PET/MRI, Philips Healthcare) for rectal cancer staging or colorectal cancer restaging. The PET acquisition of PET/MRI was similar to that of PET/CT whereas the MRI protocol was selected individually based on the patient's medical history. One nuclear medicine physician reviewed the PET/CT studies and one radiologist reviewed the PET/MRI studies independently. The diagnostic accuracy of each modality was determined in consensus, using available medical records as a reference. RESULTS: Of the 12 patients enrolled, two were for initial staging and ten for restaging. The median scan delay between the two modalities was 60 min. The initial imaging was PET/CT in nine patients and PET/MRI in three patients. When PET/CT was performed first, the SUV values of the 16 FDG avid lesions were greater at PET/MRI than at PET/CT. In contrast, when PET/MRI was performed first, the SUV values of the seven FDG avid lesions were greater at PET/CT than at PET/MRI. PET/MRI provided more detailed T staging than PET/CT. On a per-patient basis, with both patient groups combined for the evaluation of N and M staging/restaging, the true positive rate was 5/7 (71%) for PET/CT and 6/7 (86%) for PET/MRI, and true negative rate was 5/5 (100%) for both modalities. On a per-lesion basis, PET/CT identified 26 of 29 (90%) tumor lesions that were correctly detected by PET/MRI. Our proposed workflow allows for comprehensive cancer staging including integrated local and whole-body assessment. CONCLUSIONS: Our initial experience shows a high diagnostic accuracy of PET/MRI in T staging of rectal cancer compared with PET/CT. In addition, PET/MRI shows at least comparable accuracy in N and M staging as well as restaging to PET/CT. However, the small sample size limits the generalizability of the results. It is expected that PET/MRI would yield higher diagnostic accuracy than PET/CT considering the high soft tissue contrast provided by MRI compared with CT, but larger studies are necessary to fully assess the benefit of PET/MRI in colorectal cancer.

Ultrasound findings of incidental adnexal and ovarian lesions on emergency CT scans.

A search through 6076 nontraumatic emergency computed tomography (CT) scans of female patients yielded 266 (4.4%) CT scans with an incidentally detected adnexal lesion and ultrasound follow-up within 7days. The population was 87% premenopausal and 13% postmenopausal. Follow-up ultrasound yielded an ultrasound diagnosis 32% of the time. Potentially serious diagnoses included pelvic infection (3%) and suspected malignancy (2%). Benign diagnoses included normal ovaries (16%), hemorrhagic cyst (6%), and benign cyst (5%). The remaining 68% of cases were equivocal, requiring further evaluation.

Initial experience of MR/PET in a clinical cancer center.

Magentic Resonance/positron emission tomography (PET) has been introduced recently for imaging of clinical patients. This hybrid imaging technology combines the inherent strengths of MRI with its high soft-tissue contrast and biological sequences with the inherent strengths of PET, enabling imaging of metabolism with a high sensitivity. In this article, we describe the initial experience of MR/PET in a clinical cancer center along with a review of the literature. For establishing MR/PET in a clinical setting, technical challenges, such as attenuation correction and organizational challenges, such as workflow and reimbursement, have to be overcome. The most promising initial results of MR/PET have been achieved in anatomical areas where high soft-tissue and contrast resolution is of benefit. Head and neck cancer and pelvic imaging are potential applications of this hybrid imaging technology. In the pediatric population, MR/PET can decrease the lifetime radiation dose. MR/PET protocols tailored to different types of malignancies need to be developed. After the initial exploration phase, large multicenter trials are warranted to determine clinical indications for this exciting hybrid imaging technology and thereby opening new horizons in molecular imaging.

Managing incidental findings on abdominal and pelvic CT and MRI, part 1: white paper of the ACR Incidental Findings Committee II on adnexal findings.

This white paper describes adnexal (ovarian and paraovarian) incidental findings found on CT and MRI in nonpregnant postmenarchal patients in whom no adnexal disorder is clinically known or suspected. This represents the first of 4 such papers from the ACR Incidental Findings Committee II, which used a consensus method based on repeated reviews and revisions and a collective review and interpretation of relevant literature. Recommendations for the management of incidental adnexal findings are organized into 4 main categories: benign-appearing cysts, probably benign cysts, adnexal masses with characteristic features, and all other adnexal masses, with pathways on the basis of patient menstrual status or age (when last menstrual period is unknown). A table and flowchart are provided for reference.

Rare (<1%) histological subtypes of renal cell carcinoma: an update.

Recent advances in genetics and pathology have allowed description of several new histological subtypes of renal cell carcinoma (RCC) as well as better characterization of other rare subtypes. We herein present a comprehensive review of taxonomy, epidemiology, pathology, imaging findings, and natural history of a wide spectrum of rare subtypes of RCCs that individually constitute <1% of all the RCCs.

Genetics and imaging of hepatocellular adenomas: 2011 update.

Hepatocellular adenomas are benign liver neoplasms with specific but varied histopathologic findings and tumor biology. The results from recent studies of the pathologic and genetic basis of hepatocellular adenomas provide important insights into the pathogenesis and molecular changes, as well as the putative oncologic pathways used by diverse adenoma subtypes. On the basis of the genetic and pathologic features, hepatocellular adenomas are categorized into three distinct subtypes: (a) inflammatory hepatocellular adenomas, (b) hepatocyte nuclear factor 1 α-mutated hepatocellular adenomas, and (c) ß-catenin-mutated hepatocellular adenomas. Different subtypes show variable clinical behavior, imaging findings, and natural history, and thus the options for treatment and surveillance may vary. Cross-sectional imaging plays an important role in the diagnosis, subtype characterization, identification of complications, and surveillance of hepatocellular adenomas. New schemas for genotype-phenotype classification of hepatic adenomas, as well as management triage of patients with specific subtypes of adenomas, are being proposed in an attempt to improve clinical outcomes.