Biliary Duct Dilatation: AJR Expert Panel Narrative Review.

Biliary duct dilatation is a common incidental finding in practice, but it is unlikely to indicate biliary obstruction in the absence of clinical symptoms or elevated levels on liver function tests (LFTs). However, the clinical presentation may be nonspecific, and LFTs may either be unavailable or difficult to interpret. The goal of this AJR Expert Panel Narrative Review is to highlight a series of topics fundamental to the management of biliary duct dilatation, providing consensus recommendations in a question-and-answer format. We start by covering a basic approach to interpreting LFT results, the strengths and weaknesses of the biliary imaging modalities, and how and where to measure the extrahepatic bile duct. Next, we define the criteria for biliary duct dilatation, including patients with prior cholecystectomy and advanced age, and discuss when and whether biliary duct dilatation can be attributed to papillary stenosis or sphincter of Oddi dysfunction. Subsequently, we discuss two conditions in which the duct is pathologically dilated but not obstructed: congenital cystic dilatation (i.e., choledochal cyst) and intraductal papillary neoplasm of the bile duct. Finally, we provide guidance regarding when to recommend obtaining additional imaging or testing, such as endoscopic ultrasound or ERCP, and include a discussion of future directions in biliary imaging.

Reporting standards for primary sclerosing cholangitis using MRI and MR cholangiopancreatography: guidelines from MR Working Group of the International Primary Sclerosing Cholangitis Study Group.

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disorder affecting the bile ducts and is characterized by biliary strictures, progressive liver parenchymal fibrosis, and an increased risk of hepatobiliary malignancies primarily cholangiocarcinoma (CCA). PSC may lead to portal hypertension, liver decompensation, and liver failure with the need for liver transplantation. Magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) are considered the imaging standard for diagnosis and follow-up in patients with PSC. Currently, there are no universally accepted reporting standards and definitions for MRI/MRCP features. Controversies exist about the definition of a high-grade stricture and there is no widely agreed approach to their management. The members of the MRI working group of the International Primary Sclerosing Cholangitis Study Group (IPSCSG) sought to define terminologies and reporting standards for describing MRI/MRCP features that would be applied to diagnosis and surveillance of disease progression, and potentially for evaluating treatment response in clinical trials. In this extensive review, the technique of MRI/MRCP and assessment of image quality for the evaluation of PSC is briefly described. The definitions and terminologies for severity and length of strictures, duct wall thickening and hyperenhancement, and liver parenchyma signal intensity changes are outlined. As CCA is an important complication of PSC, standardized reporting criteria for CCA developing in PSC are summarized. Finally, the guidelines for reporting important changes in follow-up MRI/MRCP studies are provided. KEY POINTS: • Primary sclerosing cholangitis is a chronic inflammatory disorder affecting the bile ducts, causing biliary strictures and liver fibrosis and an increased risk of cholangiocarcinoma. • This consensus document provides definitions and suggested reporting standards for MRI and MRCP features of primary sclerosing cholangitis, which will allow for a standardized approach to diagnosis, assessment of disease severity, follow-up, and detection of complications. • Standardized definitions and reporting of MRI/MRCP features of PSC will facilitate comparison between studies, promote longitudinal assessment during management, reduce inter-reader variability, and enhance the quality of care and communication between health care providers.

Utilization of Multiparametric MRI of Prostate in Patients under Consideration for or Already in Active Surveillance: Correlation with Imaging Guided Target Biopsy.

This study sought to assess the value of multiparametric magnetic resonance image (mp-MRI) in patients with a prostate cancer (PCa) Gleason score of 6 or less under consideration for or already in active surveillance and to determine the rate of upgrading by target biopsy. Three hundred and fifty-four consecutive men with an initial transrectal ultrasound-guided (TRUS) biopsy-confirmed PCa Gleason score of 6 or less under clinical consideration for or already in active surveillance underwent mp-MRI and were retrospectively reviewed. One hundred and nineteen of 354 patients had cancer-suspicious regions (CSRs) at mp-MRI. Each CSR was assigned a Prostate Imaging Reporting and Data System (PI-RADS) score based on PI-RADS v2. One hundred and eight of 119 patients underwent confirmatory imaging-guided biopsy for CSRs. Pathology results including Gleason score (GS) and percentage of specimens positive for PCa were recorded. Associations between PI-RADS scores and findings at target biopsy were evaluated using logistic regression. At target biopsy, 81 of 108 patients had PCa (75%). Among them, 77 patients had upgrading (22%, 77 of 354 patients). One hundred and forty-six CSRs in 108 patients had PI-RADS 3 n = 28, 4 n = 66, and 5 n = 52. The upgraded rate for each category of CSR was for PI-RADS 3 (5 of 28, 18%), 4 (47 of 66, 71%) and 5 (49 of 52, 94%). Using logistic regression analysis, differences in PI-RADS scores from 3 to 5 are significantly associated with the probability of disease upgrade (20%, 73%, and 96% for PI-RADS score of 3, 4, and 5, respectively). Adding mp-MRI to patients under consideration for or already in active surveillance helps to identify undiagnosed PCa of a higher GS or higher volume resulting in upgrading in 22%.

Diagnosis of typical and atypical transition zone prostate cancer and its mimics at multiparametric prostate MRI.

Many of the current clinical screening methods for prostate cancer (PCa) such as prostate-specific antigen (PSA) testing or transrectal ultrasound-guided prostate biopsy lack sensitivity and specificity for diagnosis of PCa of the transition zone (TZ). Recent technical advances in multiparametric-MRI have markedly improved detection of PCa of the TZ. However, there are many diagnostic challenges that we still encounter in our daily practice that compromise the accuracy of the diagnosis. By performing both MRI-guided and ultrasound/MRI fusion-guided biopsies, we have gained extensive experience in the diagnosis of PCa of the TZ. Biopsy-proven examples including but not limited to typical and atypical PCa of the TZ as well as a wide variety of its mimics will be presented. Recognition of the MR features of typical and atypical PCa of the TZ and its mimics on multiparametric-MRI along with findings that help to differentiate these mimics from PCa is important in establishing an accurate diagnosis and in guiding clinical management.

Benign causes of diffusion restriction foci in the peripheral zone of the prostate: diagnosis and differential diagnosis.

Multiparametric-MRI is an important tool in the diagnosis of prostate cancer (PCa), particularly diffusion-weighted imaging for peripheral zone (PZ) cancer in the untreated prostate. However, there are many benign entities that demonstrate diffusion restriction in the PZ mimicking PCa resulting in diagnostic challenges. Fortunately, these benign entities usually have unique MR features that may help to distinguish them from PCa. The purpose of this pictorial review is to discuss benign entities with diffusion restriction in the PZ and to emphasize the key MR features of these entities that may help to differentiate them from PCa.

Pictorial review. Diagnosis of recurrent prostate cancer and its mimics at multiparametric prostate MRI.

Biochemical recurrence after treatment for prostate cancer (PCa) is a significant issue. Early diagnosis of local recurrence is important for making prompt treatment decisions and is strongly associated with patient prognosis. Without salvage therapy, the average time from development of local recurrence to distant metastasis is approximately 3 years. Biochemical recurrence does not differentiate local recurrence from systemic disease; there is no reliable way to clinically diagnose local recurrence. Recent advances in multiparametric MRI (mp-MRI) techniques have markedly improved detection of local recurrence following therapy. However, a wide variety of entities can mimic recurrent PCa at mp-MRI. Therefore, the purpose of this pictorial review is to discuss the MRI findings of locally recurrent PCa and its mimics, emphasizing the key MRI features that help to differentiate local recurrence from its mimics.

Pancreatitis in patients with pancreas divisum: imaging features at MRI and MRCP.

AIM: To determine the magnetic resonance cholangiopancreatography (MRCP) and magnetic resonance imaging (MRI) features of pancreatitis with pancreas divisum (PD) and the differences vs pancreatitis without divisum. METHODS: Institutional review board approval was obtained and the informed consent requirement was waived for this HIPAA-compliant study. During one year period, 1439 consecutive patients underwent successful MRCP without injection of secretin and abdominal MRI studies for a variety of clinical indications using a 1.5 T magnetic resonance scanner. Two experienced radiologists retrospectively reviewed all the studies in consensus. Disputes were resolved via consultation with a third experienced radiologist. The assessment included presence and the imaging findings of PD, pancreatitis, and distribution of abnormalities. The pancreatitis with divisum constituted the study group while the pancreatitis without divisum served as the control group. MRCP and MRI findings were correlated with final diagnosis. Fisher exact tests and Pearson × 2 tests were performed. RESULTS: Pancreatitis was demonstrated at MRCP and MRI in 173 cases (38 cases with and 135 cases without divisum) among the 1439 consecutive cases. The recurrent acute pancreatitis accounted for 55.26% (21 of 38) in pancreatitis patients associated with PD, which was higher than 6.67% (9 of 135) in the control group, whereas the chronic pancreatitis was a dominant type in the control group (85.19%, 115 of 135) when compared to the study group (42.11%, 16 of 38) (χ(2) = 40.494, P < 0.0001). In cases of pancreatitis with PD, the dorsal pancreatitis accounted for a much higher percentage than that in pancreatitis without PD (17 of 38, 44.74% vs 30 of 135, 22.22%) (χ(2) = 7.257, P < 0.05). CONCLUSION: MRCP and MRI can depict the features of pancreatitis associated with divisum. Recurrent acute pancreatitis and isolated dorsal involvement are more common in patients with divisum.

Blunt bowel and mesenteric injury: MDCT diagnosis.

Multidetector computed tomography (MDCT) has emerged as the imaging modality of choice for evaluating the abdomen and pelvis in trauma patients. MDCT readily detects injury of the solid organs as well as direct and indirect features of bowel and/or mesenteric injury-an important advance given that unrecognized bowel and mesenteric injuries may result in high morbidity and mortality. Nonetheless, challenges persist in the interpretation of abdominal and pelvic CT images in trauma patients. Difficulty in interpretation may result from lack of familiarity with or misunderstanding of CT features of bowel and/or mesenteric injury. Moreover, due to major technical advances afforded by MDCT, new CT features of bowel and/or mesenteric injuries have been recognized. Beading and termination of mesenteric vessels indicating surgically important mesenteric injury is an example of one of these new features. MDCT also allows for the detection of small or trace amounts of isolated intraperitoneal fluid in trauma patients, although the clinical management of these patients is still controversial. This pictorial essay illustrates the spectrum of typical, atypical, and newly reported MDCT features of bowel and mesenteric injuries due to blunt trauma. The features that help to differentiate these injuries from pitfalls are emphasized in these proven cases.

Frequency and importance of small amount of isolated pelvic free fluid detected with multidetector CT in male patients with blunt trauma.

PURPOSE: To retrospectively determine the frequency and importance of a small amount of isolated pelvic free fluid seen at multidetector computed tomography (CT) in male patients who have blunt trauma without an identifiable cause. MATERIALS AND METHODS: Institutional review board approval was obtained, and the requirement for informed consent was waived for this HIPAA-compliant study. One thousand male patients with blunt trauma who underwent abdominopelvic CT at a level 1 trauma center between January 2004 and June 2006 were entered into this study. The CT images of the 1000 patients were reviewed independently by two abdominal radiologists. CT scan assessment included evaluation for presence or absence of pelvic free fluid, any traumatic or nontraumatic cause of the free fluid, pelvic free fluid attenuation and volume measurements, and determination of the location of pelvic free fluid. Interobserver agreement was determined with kappa statistics, and the Student t test was used to assess differences in the mean volume and mean attenuation of the pelvic free fluid in the patients with and those without injury. RESULTS: Pelvic free fluid was identified in 10.2% (102 of 1000) of patients. A small amount of isolated pelvic free fluid without any identifiable cause was identified in 4.8% (48 of 1000) of patients by reader 1 and in 5.0% (50 of 1000) of patients by reader 2 (kappa value, 0.76) and was located at or below the level of the third sacral vertebral body in all 49 patients with isolated pelvic free fluid. The mean volume and mean attenuation of the small amount of isolated pelvic free fluid were 2.3 mL +/- 1.5 (standard deviation) and 8.1 HU +/- 3.9, respectively. None of the patients in this group had an undiagnosed bowel and/or mesenteric injury. CONCLUSION: In male patients with blunt trauma, a small amount of isolated pelvic free fluid with attenuation equal to that of simple fluid and located in the deep region of the pelvis likely is not a sign of bowel and/or mesenteric injury.

Congenital anomalies and normal variants of the pancreaticobiliary tract and the pancreas in adults: part 1, Biliary tract.

OBJECTIVE: The purpose of this article is to highlight the imaging features of congenital anomalies and normal variants of the biliary tract with contemporary imaging techniques such as MR cholangiopancreatography (MRCP), MRI, and helical CT. CONCLUSION: Recognizing findings of congenital anomalies and normal variants of the biliary tract at MRCP, MRI, and helical CT, and knowledge of the clinical significance of each entity, are important for establishing a correct diagnosis and in guiding appropriate clinical management.

Congenital anomalies and normal variants of the pancreaticobiliary tract and the pancreas in adults: part 2, Pancreatic duct and pancreas.

OBJECTIVE: The purpose of this article is to highlight the imaging features of congenital anomalies and normal variants of the pancreatic duct and the pancreas using contemporary imaging techniques such as MR cholangiopancreatography (MRCP), MRI, and helical CT. CONCLUSION: Congenital anomalies and normal variants of the pancreatic duct and the pancreas may be clinically significant and may create a diagnostic challenge. Recognition of the updated imaging features of these entities is important in clinical management and for avoiding misdiagnosis.

Abdominal imaging features of HELLP syndrome: a 10-year retrospective review.

OBJECTIVE: The purpose of this study was to describe the abdominal imaging features associated with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, a complication of pregnancy. CONCLUSION: The abdominal imaging features of HELLP syndrome include intraparenchymal and perihepatic hematomas and hemoperitoneum as noted on sonography, CT, and angiography.

Helical CT evaluation of acute right lower quadrant pain: part I, common mimics of appendicitis.

OBJECTIVE: The purpose of our pictorial essay is to present common mimics of appendicitis as noted on helical CT in patients with right lower quadrant pain and to highlight the features that provide clues to the diagnosis. CONCLUSION: Recognition of the findings of common diseases that simulate acute appendicitis on helical CT, along with features that help to differentiate these entities from appendicitis, is important in establishing a correct diagnosis and in guiding appropriate therapy.

Helical CT evaluation of acute right lower quadrant pain: part II, uncommon mimics of appendicitis.

OBJECTIVE: The purpose of our pictorial essay is to highlight the helical CT features of uncommon mimics of appendicitis and to provide clues to differentiate them from appendicitis. CONCLUSION: Uncommon mimics of appendicitis create a diagnostic challenge in patients with right lower quadrant pain. Recognition of the helical CT features of uncommon mimics of appendicitis is important in clinical management and avoiding unnecessary laparotomy.