Management of Patients With Common Bile Duct Dilatation Without a Sonographic Evident Cause: Evaluating the Yield of Subsequent Magnetic Resonance Imaging and Findings Correlated With Causative Pancreaticobiliary Pathology.

OBJECTIVES: The aims of the study were to evaluate the yield of magnetic resonance imaging (MRI) in patients with common bile duct (CBD) dilatation without a sonographic evident cause and to investigate sonographic and laboratory findings at presentation that might predict identification of underlying pancreaticobiliary pathology. METHODS: Included were consecutive patients in whom MRI was performed for further evaluation of CBD dilatation detected on ultrasound (US), without a sonographic evident cause, from January 1, 2014, to December 31, 2014. Magnetic resonance imaging and clinical data were retrospectively reviewed. Patients were divided into two groups: patients with and without identified underlying causative pancreaticobiliary pathology. Ultrasound findings and laboratory results at presentation were compared between groups to identify findings suggestive of underlying pancreaticobiliary pathology. RESULTS: Fifty-seven patients, with a mean age of 54 ± 16 years including 37 females (65%), underwent MRI. Specific pancreaticobiliary causes for CBD dilatation were identified in 38 patients (66%, 31 benign and 7 malignant). In the remaining patients, no cause was identified in 17 (30%) and MRIs were nondiagnostic in 2 patients. Magnetic resonance imaging accuracy for correctly identifying the underlying cause of CBD dilatation was 91%. Patients with associated intrahepatic bile duct dilatation on US and elevated alanine aminotransferase and alkaline phosphatase were more likely to have underlying pancreaticobiliary pathology (P < 0 .05). No patient with initial negative MRI had pancreaticobiliary malignancy. CONCLUSIONS: Magnetic resonance imaging seems to be an accurate noninvasive method for identifying the underlying cause in most patients with CBD dilatation on US and in excluding pancreaticobiliary malignancy. Patients with associated intrahepatic bile duct dilatation and/or elevated liver enzymes are at higher risk of harboring underlying pancreaticobiliary pathology.

The "Speckle Sign" in the Diagnosis of Posterior Compartment Endometriosis.

OBJECTIVE: To determine usefulness of the "speckle sign" in the diagnosis of deep invasive endometriosis. MATERIALS AND METHODS: This HIPAA-compliant, institutional review board-approved retrospective study with informed consent waived included 25 women (mean age 20-69 years) with histopathologically confirmed posterior cul-de-sac endometriosis between 2013 and 2018. Transvaginal ultrasound exams of these patients were reviewed by 2 expert radiologists searching for the "speckle sign," defined as irregular obliteration of the posterior cul-de-sac and bright (hyperechoic) internal echoes. The frequency of additional findings such as "kissing ovaries," endometriomas in the adnexa, bowel tethering in the posterior pelvic compartment, retroflexed uterus, adenomyosis, and pelvic free fluid were also analyzed. Data regarding clinical features, histopathologic findings and management were collected through a review of the medical record. RESULTS: Reader one identified posterior compartment endometriosis in 20/25 patients, and reader two in 22/25 patients, with 96% agreement. Adnexal endometriomas were found in 21/25 patients for both readers (k = 0.70) and were bilateral in 23% of patients. The ovaries were adherent to each other in the midline ("kissing ovaries") in 50% of patients; the bowel was tethered anteriorly in 20%; the presence of adenomyosis was seen in about 27%, and a retroflexed uterus was seen in 24% of patients. CONCLUSIONS: The speckle sign could be helpful in making the diagnosis of posterior compartment endometriosis, and the sign is often found in conjunction with other imaging features of endometriosis.

Use of ring-enhancement and focal necrosis to differentiate pancreatic adenosquamous carcinoma from pancreatic ductal adenocarcinoma on CT and MRI.

PURPOSE: To assess the ability of the ring-enhancing sign and focal necrosis to diagnose adenosquamous carcinoma (ASqC), a variant of pancreatic ductal adenocarcinoma (PDAC), on MRI and CT. METHODS: The following features of ASqC and conventional PDAC were evaluated on CT and MRI: tumor size, location, margins, borders (non-exophytic, exophytic), and T1 signal intensity. Two readers, blinded to histopathology results, rated their confidence in detecting ring-enhancement and focal necrosis (FN) on a 5-point Likert scale on both MRI and CT. Inter-reader agreement was assessed with Cohen's kappa (k). RESULTS: A total of 24 patients were included: eight patients with treatment naïve and histologically proven ASqC (six women, mean age: 63, range: 40-75) and 16 patients with PDAC (eight women, mean age: 67, range: 47-83). Statistically significant differences between ASqC and PDAC were seen in tumor size, location, presence of FN, and ring enhancement (p = 0.01-0.037). The readers were more confident in depicting the key differentiating feature ring-enhancement in ASqC on MRI compared to CT (confidence 1.71 ± 0.49 vs. 0.88 ± 0.35, p = 0.017) with moderate inter-reader agreement (k = 0.46 and 0.5, respectively). FN showed substantial inter-reader agreement on MR and moderate agreement on CT (k = 0.67 and 0.5, respectively). CONCLUSIONS: Compared to CT, MRI depicts ring-enhancement in ASqC with greater reader confidence and FN in ASqC with higher inter-reader agreement. The concurrent presence of these two imaging features should raise high suspicion for ASqC.

Lumen-apposing covered self-expanding metallic stent for symptomatic pancreatic fluid collections: assessment of outcomes and complications with CT and MRI.

PURPOSE: To assess technical and clinical outcomes following lumen-apposing covered self-expanding metallic stent (LAMS) placement for symptomatic pancreatic fluid collections (PFC) with CT and MRI. METHODS: In this retrospective study, patients with PFC who underwent LAMS placement between March 2015 and June 2018 were included. Primary outcomes included technical success, defined as successful stent placement with resolution of PFC, and clinical success, defined as lack of fluid recurrence after stent removal. Secondary outcomes included time duration from stent placement to removal, complications, and re-intervention need. RESULTS: 28 consecutive patients (20 men, mean age: 53 years ± 17; range 21-75) who underwent endoscopic drainage of symptomatic walled-off necrosis (WON, 21/28, 75%), pseudocyst (PC, 5/28, 18%) or acute necrotic collection (ANC, 2/28, 7%) were included. LAMS were placed successfully in 27/28 (96%) patients. On follow-up imaging after at least one month (n = 24), the volume of the PFC decreased by 99.9% from 425 cm3 [IQR 214 - 636] to 0.6 cm3 [IQR 0-43.9]. After stent removal, 26/27 (96%) patients remained collection free. The median time duration from stent placement to removal was 42 days [IQR 34-71]. Complications (10/28; 36%) included stent occlusion (n = 1), stent migration (n = 3), intraprocedural bleeding (n = 2), postprocedural bleeding (n = 2), and pseudoaneurysm formation (n = 2). Re-intervention was required in 7/27 (26%). CONCLUSION: Following LAMS placement in patients with symptomatic PFC, high technical and clinical success rates of 96% and 96%, respectively, are achieved. Awareness of common complications seen on cross-sectional imaging might help radiologists and gastroenterologist in the patients' management.

MRI characterization of focal liver lesions in non-cirrhotic patients: assessment of added value of gadoxetic acid-enhanced hepatobiliary phase imaging.

BACKGROUND: To evaluate the added value of the hepatobiliary (HPB) phase in gadoxetic acid-enhanced magnetic resonance imaging (MRI) in characterizing newly discovered indeterminate focal liver lesions in non-cirrhotic patients. RESULTS: One-hundred and twenty-five non-cirrhotic patients (median age, 46 years; range, 20-85 years; 100 females) underwent gadoxetic acid-enhanced MRI, including the 20-min delayed HPB phase, for characterization of newly discovered focal liver lesions. Images were independently evaluated by two blinded, board-certified abdominal radiologists (R1 and R2) who characterized liver lesions without and with assessment of the HPB phase images in two separate readout sessions. Confidence in diagnosis was scored on a scale from 0 to 3. Inter-observer agreement was assessed using Cohen κ statistics. Change in diagnosis and confidence in diagnosis were evaluated by Wilcoxon signed rank test. There was no significant change in diagnosis before and after evaluation of the HPB phase for both readers (p = 1.0 for R1; p = 0.34 for R2). Confidence in diagnosis decreased from average 2.8 ± 0.45 to 2.6 ± 0.59 for R1 and increased from 2.6 ± 0.83 to 2.8 ± 0.46 for R2. Change in confidence was only statistically significant for R1 (p = 0.003) but not significant for R2 (p = 0.49). Inter-reader agreement in diagnosis was good without (k = 0.66) and with (k = 0.75) inclusion of the HPB phase images. CONCLUSIONS: The added information obtained from the HPB phase of gadoxetic acid-enhanced MRI does not change the diagnosis or increase confidence in diagnosis when evaluating new indeterminate focal liver lesions in non-cirrhotic patients.

Pancreatic Ductal Adenocarcinoma and Its Variants: Pearls and Perils.

Pancreatic ductal adenocarcinoma (PDAC), an epithelial neoplasm derived from the pancreatic ductal tree, is the most common histologic type of pancreatic cancer and accounts for 85%-95% of all solid pancreatic tumors. As a highly lethal malignancy, it is the seventh leading cause of cancer death worldwide and is responsible for more than 300 000 deaths per year. PDAC is highly resistant to current therapies, affording patients a 5-year overall survival rate of only 7.2%. It is characterized histologically by its highly desmoplastic stroma embedding tubular and ductlike structures. On images, it typically manifests as a poorly defined hypoenhancing mass, causing ductal obstruction and vascular involvement. Little is known about the other histologic subtypes of PDAC, mainly because of their rarity and lack of specific patterns of disease manifestation. According to the World Health Organization, these variants include adenosquamous carcinoma, colloid carcinoma, hepatoid carcinoma, medullary carcinoma, signet ring cell carcinoma, undifferentiated carcinoma with osteoclast-like giant cells, and undifferentiated carcinoma. Depending on the subtype, they can confer a better or even worse prognosis than that of conventional PDAC. Thus, awareness of the existence and differentiation of these variants on the basis of imaging and histopathologic characteristics is crucial to guide clinical decision making for optimal treatment and patient management.

Correction to: Effects of Physician Experience, Specialty Training, and Self-referral on Inappropriate Diagnostic Imaging.

There were some errors in the variables in this paper.

Accuracy of a novel noninvasive secretin-enhanced MRCP severity index scoring system for diagnosis of chronic pancreatitis: correlation with EUS-based Rosemont criteria.

PURPOSE: To evaluate the accuracy of a secretin-enhanced MRCP Chronic Pancreatitis Severity Index (CPSI) in the diagnosis of chronic pancreatitis (CP) based on endoscopic ultrasound (EUS) Rosemont criteria. METHODS: In this retrospective study, 31 patients (20 women; median age 48 years, range 18-77) with known/suspected CP evaluated with both EUS and secretin-enhanced MRCP were included. CP severity was graded using a ten-point-scale secretin-enhanced MRCP-based CPSI scoring system which considered ductal, parenchymal and secretin-based dynamic abnormalities. Cases were categorized as normal, mild, moderate or severe CP. Correlation between CPSI and the EUS Rosemont criteria was performed using Cohen's kappa coefficient. Comparative evaluation of test performance was obtained using ROC analysis. RESULTS: Using EUS Rosemont criteria, eight patients had features consistent/suggestive of CP, 20 patients were normal and three were indeterminate. On CPSI, five patients were normal, 12 had mild and 14 had moderate/severe CP. There was only fair agreement (k = 0.272) between CPSI and Rosemont criteria categories. CPSI showed 87.5% sensitivity, 69.6% specificity and 74.2% accuracy (cutoff value = 3.5 points; area under the curve = 0.804; p = 0.0026) for CP diagnosis based on EUS Rosemont criteria. CONCLUSION: CPSI showed relatively high diagnostic accuracy for diagnosis of CP based on Rosemont criteria. The CPSI scoring system can be proposed as a noninvasive alternative to the EUS Rosemont criteria for CP diagnosis.

Imaging of gastrointestinal endometriosis: what the radiologist should know.

Deep invasive gastrointestinal endometriosis (DIGIE) is a frequent and severe presentation of endometriosis. Although most cases invade the rectosigmoid colon, DIGIE can involve any portion of the gastrointestinal tract from the stomach to the rectum, and is commonly multifocal and multicentric. Although histopathologic confirmation with surgery remains the gold standard for diagnosis, ultrasound (US) and magnetic resonance imaging (MRI) are the key non-invasive imaging modalities for initial assessment. US may be preferred as a screening study because of its easy availability and low-cost. Pelvic MRI and magnetic resonance enterography (MRE) provide substantial advantages for disease mapping in the pre-operative period, particularly in extensive bowel endometriosis. Although medical management of DIGIE with hormonal therapy can help control symptoms, disease course can be relentless and require surgical intervention. Surgical options depend on, the location; length; depth; circumference; multicentric or multifocal disease. With procedures including simple excision, fulguration of superficial lesions, shaving, disc excision, and segmental resection. A successful treatment outcome is largely dependent on good communication between the treating surgeon and the radiologist, who can provide vital information for effective surgical planning by reporting the key elements that we elaborate upon in this paper.

Genetic Syndromes Affecting Both Children and Adults: A Practical Guide to Imaging-based Diagnosis, Management, and Screening Recommendations for General Radiologists.

Genetic syndromes are an infrequently encountered but challenging group of conditions for both pediatric and adult radiologists given the multitude of possible findings and important complications associated with these syndromes. This article reviews characteristic syndromic imaging features, as well as discussing important complications and screening recommendations for a selected group of clinically relevant genetic syndromes affecting both pediatric and adult populations.

Reporting of acute pancreatitis by radiologists-time for a systematic change with structured reporting template.

Acute pancreatitis has a wide array of imaging presentations. Various classifications have been used in the past to standardize the terminology and reduce confusing and redundant terms. We aim to review the historical and current classifications of acute pancreatitis and propose a new reporting template which can improve communication between various medical teams by use of appropriate terminology and structured radiology template. The standardized reporting template not only conveys the most important imaging findings in a simplified yet comprehensive way but also allows structured data collection for future research and teaching purposes.

Effects of Physician Experience, Specialty Training, and Self-referral on Inappropriate Diagnostic Imaging.

BACKGROUND: Although previous research has demonstrated high rates of inappropriate diagnostic imaging, the potential influence of several physician-level characteristics is not well established. OBJECTIVE: To examine the influence of three types of physician characteristics on inappropriate imaging: experience, specialty training, and self-referral. DESIGN: A retrospective analysis of over 70,000 MRI claims submitted for commercially insured individuals. Physician characteristics were identified through a combination of administrative records and primary data collection. Multi-level modeling was used to assess relationships between physician characteristics and inappropriate MRIs. SETTING: Massachusetts PARTICIPANTS: Commercially insured individuals who received an MRI between 2010 and 2013 for one of three conditions: low back pain, knee pain, and shoulder pain. MEASUREMENTS: Guidelines from the American College of Radiology were used to classify MRI referrals as appropriate/inappropriate. Experience was measured from the date of medical school graduation. Specialty training comprised three principal groups: general internal medicine, family medicine, and orthopedics. Two forms of self-referral were examined: (a) the same physician who ordered the procedure also performed it, and (b) the physicians who ordered and performed the procedure were members of the same group practice and the procedure was performed outside the hospital setting. RESULTS: Approximately 23% of claims were classified as inappropriate. Physicians with 10 or less years of experience had significantly higher odds of ordering inappropriate MRIs. Primary care physicians were almost twice as likely to order an inappropriate MRI as orthopedists. Self-referral was not associated with higher rates of inappropriate MRIs. LIMITATIONS: Classification of MRIs was conducted with claims data. Not all self-referred MRIs could be detected. CONCLUSIONS: Inappropriate imaging continues to be a driver of wasteful health care spending. Both physician experience and specialty training were highly associated with inappropriate imaging.

Pelvic MRI in the diagnosis and staging of pelvic endometriosis: added value of structured reporting and expertise.

PURPOSE: To compare the diagnostic characteristics of routine-read (RR), structured-reported read (SR), and structured expert-read pelvic (SER) MRI for staging of pelvic endometriosis in a tertiary care academic center. METHODS: Of 530 patients with endometriosis (2013-2018), 59/530 (11.1%) were staged surgically and underwent pelvic MRI. Radiology reports were considered RR; MRI studies were independently reassessed by SR and SER. Involvement was recorded by compartment [anterior (AC), middle (MC), posterior (PC), adnexal (AX), and other (OC)]. Diagnostic discrepancy between review methods was assessed with McNemar's test. Interobserver agreement was assessed using Cohen's unweighted kappa. RESULTS: Of 295 compartments in 59 women (mean age = 38.8 years; range 20-69), 147/295 (49.8%) had confirmed endometriosis. Overall sensitivity: RR = 42.9%; SR = 86.4%; SER = 74.2%. SR's increased sensitivity was significant for PC (p < 0.001), MC (p < 0.001), AC (p = 0.001), AX (p = 0.038). Higher sensitivity by SER was significant for PC (p < 0.001), MC (p = 0.004) and AC (p < 0.001), but not AX (p > 0.05). Overall specificity: RR = 95.3%; SR = 45.9%; SER = 81.8%. SER specificity was no different than RR for PC or AX (p > 0.5). RR sensitivity relied heavily on detection of AX involvement, whereas SR and SER showed additional sites of disease while maintaining comparable specificity for SER. Overall agreement between SR and SER was fair [k = 0.342 (95% CI 0.25, 0.44)]. CONCLUSIONS: Even at a tertiary care academic center, SER outperforms both SR and RR in the assessment of pelvic endometriosis. Although lack of expertise may negatively impact specificity, use of structured reporting is significantly more sensitive than RR. Therefore, its use can be of assistance in surgical planning and patient counseling.

Multimodality imaging and clinicopathologic assessment of abdominal wall endometriosis: knocking down the enigma.

PURPOSE: To review the clinical, multimodality imaging, and pathologic characteristics of abdominal wall endometriosis (AWE), the most common type of extra-pelvic endometriosis. METHODS: 116 women with histopathologically confirmed extragenital endometriosis diagnosed between 2/2014 and 6/2017 were evaluated retrospectively. Of these, 26 (22.4%) were found to have AWE and 18/26 met inclusion criteria for imaging. Available imaging studies were re-reviewed by two expert radiologists. Data regarding clinical features, histopathologic findings, and management were collected through medical record review. RESULTS: 21 pathology-proven AWE deposits were identified by imaging in 18 women [mean age at diagnosis of 38.5 years (range 31-48)]. Prior C-section was present in 15/18 (83.3%) and pelvic endometriosis in 3/18 (16.7%) patients. Patients presented with abdominal pain in 14/18 (77.8%) cases, which was cyclical in 8/14; palpable mass in 12/18 (66.7%); fluid discharge in 2/18 (11.1%); and local skin discoloration in 2/18 (11.1%). Of the 21 lesions, 15 were evaluated with US, 10 with CT, and 5 with MRI. Mean lesion dimensions were 2.5 × 2.2 × 2.6 cm, and deposits were predominantly located at midline or left hemiabdomen [22/30 (73.3%)], were either stellate [15/30 (50%)] or round [15/30 (50%)] in shape, had ill-defined margins [21/30 (70%)], were heterogenous in appearance [27/30 (90%)], and involved both deep and superficial abdominal wall layers [17/30 (56.7%)]. On US, lesions were mainly isoechoic/hyperechoic [7/15 (46.7%)], and scarcely vascular [8/15 (53.3%)] with a peripheral vascular pattern [8/13 (61.5%)]. On CT, AWEs were hypervascular and homogeneous [8/10 (80%)], superiorly located to scar tissue, and on MRI lesions appeared hyperintense [4/5 (80%)] to muscle with T2 cystic and T1 hemorrhagic foci [4/5 (80%)]. In 23/27 (85.1%) original reports, there was at least one known mass prior to imaging; AWE was correctly diagnosed in only 7/23 (30.4%) cases. In those with no prior knowledge of a mass, the lesion was detected in 3/4 (75%), but AWE was only diagnosed in a single case. Median time between onset of symptoms and histopathology was 24.41 moths (IQR 15.18-47.33). CONCLUSIONS: AWE is a challenging clinical entity frequently diagnosed with a significant delay and easily misinterpreted despite multimodality imaging. Familiarity with its radiologic features holds the potential for positively impacting diagnosis.

Pancreatic perfusion modulation following glucose stimulation assessed by noninvasive arterial spin labeling (ASL) MRI.

BACKGROUND: More than 100 million adults in the US suffer from prediabetes or type-2 diabetes. Noninvasive imaging of pancreas endocrine function might provide a surrogate marker of ß-cell functional integrity loss linked to this disease. PURPOSE: To noninvasively assess pancreatic blood-flow modulation following a glucose challenge using arterial spin labeling (ASL) MRI. STUDY TYPE: Prospective. SUBJECTS: Fourteen adults (30 ± 7 years old, 3M/11F, body mass index [BMI] = 24 ± 3 kg.m-2 ). FIELD STRENGTH/SEQUENCE: 3T MRI / background-suppressed pseudocontinuous PCASL preparation with single-shot fast-spin-echo (FSE) readout before and after an oral glucose challenge using either fruit juice (n = 7) or over-the-counter glucose gel (n = 7). ASSESSMENT: Subjects were fasting prior to initiation of oral stimulation, then dynamic perfusion measurements were performed every 2 minutes for 30 minutes. We quantified absolute blood flow at each timepoint. STATISTICAL TESTS: Repeated-measures analysis of variance (ANOVA) followed by paired t-tests to assess for a significant effect of glucose challenge on measured perfusion. RESULTS: Measured basal blood flow was 187 ± 53 mL/100g/min. A significant blood flow increase of +38 ± 26% was observed 10 minutes poststimulation (P < 0.05) and continuing until the end of the experiment. The gel stimulation provided the most consistent results, with an early rise followed by an additional later increase consistent with the known pancreatic insulin response to elevated blood glucose. Across-subject variations in blood flow increase were partially attributable to basal flow, with a negative correlation of r = -0.84 between basal and maximal relative flow increase in the gel group. DATA CONCLUSION: ASL can be used to measure pancreatic flow in response to a glucose challenge, which could be linked to insulin release and secretion. This paradigm might be useful to characterize disorders of glucose regulation. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:854-860.

Retroperitoneal cystic masses: magnetic resonance imaging features.

The objective of this review is to discuss the clinical and histopathologic features, MRI characteristics, and management options of retroperitoneal cystic masses. Radiologists should be familiar with the MR imaging characteristics of retroperitoneal cystic masses to allow for a refined differential diagnosis, assist with lesion management, and prevent unnecessary invasive procedures.

Feasibility, safety, and utility of brain MRI for patients with non-MRI-conditioned CIED.

Feasibility, safety, and utility of brain MRI for patients with non-MRI-conditioned cardiac implantable electrical devices (CIEDs) remains controversial. While a growing number of studies have shown safe employment in select patients under strict protocols, there is an increasing clinical need for further off-label investigations. To assess the feasibility and utility of brain MRI in neurological and neurosurgical patients with non-MRI-conditioned CIEDs using off-label protocol. We retrospectively evaluated 126 patients with non-MRI-conditioned CIEDs referred to our hospital between 2014 to 2018 for MRI under an IRB-approved protocol. A total of 126 off-label brain MRI scans were performed. The mean age was 67.5 ± 13.0. Seventy percent of scans were performed on female patients. Indications for MRI are neurosurgical (45.2%), neurological (51.6%), and others (3.2%). MRI utilization for tumor cases was highest for tumor cases (68.3%), but employment was valuable for vascular (12.7%), deep brain stimulators (3.2%), and other cases (15.9%). In the tumor category, (37.2%) of the scans were performed for initial diagnosis and pre-surgical planning, (47.7%) for post-intervention evaluation/surveillance, (15.1%) for stereotactic radiosurgery treatment (CyberKnife). No clinical complications were encountered. No functional device complications of the CIED were identified during and after the MRI in 96.9% of the studies. A 49.6% of the off-label brain MRI scans performed led to a clinically significant decision and/or intervention for the patients. A 42.9% of obtained MRI studies did not change the plan of care. A 7.9% of post-scan decision-making data was not available. We demonstrate that off-label brain MRI scans performed on select patients under a strict protocol is feasible, safe, and relevant. Almost 50% of scans provided critical information resulting in clinical intervention of the patients.

Imaging guidelines for acute pancreatitis: when and when not to image.

In patients with acute pancreatitis (AP), diagnostic imaging is performed for various reasons, including the detection of the etiology (e.g., biliary obstruction caused by gallstones), diagnosis of pancreatitis in an unclear clinical setting, assessment of the severity of the process, and evaluation of its complications. In spite of the potential benefits of these imaging studies in the setting of AP, especially economic consequences but also medical risks are associated with diagnostic imaging, including increase of the effective radiation dose received by patients with AP and rising health care costs, frequently without impact on management. The rising incidence of acute pancreatitis in the Western world is escalating its financial burden with national health care expenses of over 2.5 billion dollars annually. Despite evidence-based national recommendations on utilization of diagnostic imaging in patients with AP, unnecessary imaging studies are still frequently performed, especially in the early hospital course. The purpose of this article is, therefore, to review the imaging guidelines for acute pancreatitis with regards to when and when not to image, with the aim to minimize inappropriate utilization.

Incidental finding of a supradiaphragmatic caudate lobe on cross-sectional imaging: An exceedingly rare entity.

Intrathoracic accessory lobes of the liver are exceedingly rare and usually found incidentally in asymptomatic patients. Its diagnosis poses a real challenge for radiologists due to its rarity, location and rounded solid mass appearance. Herein, we describe the case of a supradiaphragmatic caudate lobe of the liver in a 43-year-old African American woman presenting to the hospital for evaluation of an inferior vena cava (IVC) thrombus with CT. Final diagnosis was achieved by MRI using intravenous contrast material, showing a 4.7 cm by 2.7 cm oval shaped mass, with similar signal intensity to the main liver on all sequences. Appropriate diagnosis of this intrathoracic mass is important to negate the need for unnecessary procedures and set a proper follow up after clinical diagnosis.

Incidental pulmonary embolism in pancreatic ductal adenocarcinoma: Impact of tumor and AJCC stages at initial staging CT.

BACKGROUND/OBJECTIVES: To determine the prevalence of incidental pulmonary embolism (PE) detected during initial staging CT among patients with newly diagnosed pancreatic ductal adenocarcinoma (PDAC) and assess their association with underlying tumor burden. MATERIALS AND METHODS: This retrospective cohort study evaluated staging chest CT scans (2013-2017) to identify PE among patients with treatment naïve, biopsy-proven PDAC. Data included age, sex, T stage, AJCC stage, presence/absence of metastases and their location at diagnosis. The association of PE with tumor (T1-T4) and AJCC stage were assessed using Pearson Chi-square and Fischer's exact test. A threshold p-value of <0.05 indicated statistical significance. RESULTS: A total of 174 patients (90 female, mean age, 68 years; range: 34-93) were identified, of which 10 patients harbored incidental PE (prevalence, 5.7%). In the PE group, two patients presented with distant metastasis (liver, 20%), while eight patients had T4 tumors (80%). No statistical association was detected between PE and age, sex, and the presence/absence or location of distant metastasis (p = 0.065, p = 0.59, p = 0.687 and p = 0.933, respectively). Patients with T4 tumors and higher AJCC stages (stage III/IV) were significantly more likely to present with PE than those with lower T stage (p = 0.045) and AJCC stage (stage I/II; p = 0.017). CONCLUSION: The prevalence of incidental PE among PDAC patients undergoing initial CT staging is 5.7%. Patients with T4 and AJCC stages III/IV are at higher risk of PE. Caution should be exercised during radiographic interpretation of initial staging chest CTs, as incidental PE may be lurking and require treatment.