Contrast-enhanced US Evaluation of Hepatocellular Carcinoma Response to Chemoembolization: A Prospective Multicenter Trial.

Background Contrast-enhanced (CE) US has been studied for use in the detection of residual viable hepatocellular carcinoma (HCC) after locoregional therapy, but multicenter data are lacking. Purpose To compare two-dimensional (2D) and three-dimensional (3D) CE US diagnostic performance with that of CE MRI or CT, the current clinical standard, in the detection of residual viable HCC after transarterial chemoembolization (TACE) in a prospective multicenter trial. Materials and Methods Participants aged at least 21 years with US-visible HCC scheduled for TACE were consecutively enrolled at one of three participating academic medical centers from May 2016 to March 2022. Each underwent baseline 2D and 3D CE US before TACE, 2D and 3D CE US 1-2 weeks and/or 4-6 weeks after TACE, and CE MRI or CT 4-6 weeks after TACE. CE US and CE MRI or CT were evaluated by three fellowship-trained radiologists for the presence or absence of viable tumors and were compared with reference standards of pathology (18%), angiography on re-treatment after identification of residual disease at 1-2-month follow-up imaging (31%), 4-8-month CE MRI or CT (42%), or short-term (approximately 1-2 months) CE MRI or CT if clinically decompensated and estimated viability was greater than 50% at imaging (9%). Diagnostic performance criteria, including sensitivity and specificity, were obtained for each modality and time point with generalized estimating equation analysis. Results A total of 132 participants were included (mean age, 64 years ± 7 [SD], 87 male). Sensitivity of 2D CE US 4-6 weeks after TACE was 91% (95% CI: 84, 95), which was higher than that of CE MRI or CT (68%; 95% CI: 58, 76; P < .001). Sensitivity of 3D CE US 4-6 weeks after TACE was 89% (95% CI: 81, 94), which was higher than that of CE MRI or CT (P < .001), with no evidence of a difference from 2D CE US (P = .22). CE MRI or CT had 85% (95% CI: 76, 91) specificity, higher than that of 4-6-week 2D and 3D CE US (70% [95% CI: 56, 80] and 67% [95% CI: 53, 78], respectively; P = .046 and P = .023, respectively). No evidence of differences in any diagnostic criteria were observed between 1-2-week and 4-6-week 2D CE US (P > .21). Conclusion The 2D and 3D CE US examinations 4-6 weeks after TACE revealed higher sensitivity in the detection of residual HCC than CE MRI or CT, albeit with lower specificity. Importantly, CE US performance was independent of follow-up time. Clinical trial registration no. NCT02764801 © RSNA, 2023 Supplemental material is available for this article.

Extrapancreatic Advanced Endoscopic Interventions.

As the field of interventional endoscopy advances, conditions that were once treated with surgery are increasingly being treated with advanced endoscopy. Endoscopy is now used for treatment of achalasia, bariatric procedures for obesity; resection of early-stage malignancies in the gastrointestinal tract; and placement of lumen-apposing metal stents in the treatment of biliary obstruction, gastric outlet obstruction, cholecystitis, and drainage of nonpancreatic-related fluid collections or abscesses. Knowledge of the novel terminology, procedural details, expected postintervention imaging findings, and potential complications is vital for radiologists because these procedures are rapidly becoming more mainstream in daily practice. These procedures include peroral endoscopic myotomy for the treatment of achalasia and other esophageal motility disorders; endoscopic sleeve gastroplasty and placement of an intragastric balloon for weight loss; endoscopic submucosal dissection in the resection of tumors of the gastrointestinal tract; and therapeutic endoscopic-guided procedures for the treatment of biliary obstruction, gastric outlet obstruction, acute cholecystitis, and drainage of nonpancreatically related fluid collections. Patients benefit from these minimally invasive procedures, with potential improvement in morbidity and mortality rates, decreased length of hospital stay, and decreased health care costs when compared with the surgical alternative. Complications of these procedures include leaks or perforations, infections or abscesses, fistulas, and occlusion and migration of stents. An invited commentary by Pisipati and Pannala is available online. ©RSNA, 2022.

Contributions of Magnetic Resonance Imaging to Gastroenterological Practice: MRIs for GIs.

MRI has transformed from the theoretical, investigative realm to mainstream clinical medicine over the past four decades and has become a core component of the diagnostic toolbox in the practice of gastroenterology (GI). Its success is attributable to exquisite contrast and the ability to isolate specific proton species through the use of different pulse sequences (i.e., T1-weighted, T2-weighted, diffusion-weighted) and exploiting extracellular and hepatobiliary contrast agents. Consequently, MRI has gained preeminence in various GI clinical applications: liver and pancreatic lesion evaluation and detection, liver transplantation evaluation, pancreatitis evaluation, Crohn's disease evaluation (using MR enterography) rectal cancer staging and perianal fistula evaluation. MR elastography, in concert with technical innovations allowing for fat and iron quantification, provides a noninvasive approach, or "MRI virtual liver biopsy" for diagnosis and management of chronic liver diseases. In the future, the arrival of ultra-high-field MR systems (7 T) and the ability to perform magnetic resonance spectroscopy in the abdomen promise even greater diagnostic insight into chronic liver disease.

Contrast-enhanced or noncontrast CT for renal colic: utilizing urinalysis and patient history of urolithiasis to decide.

PURPOSE: In the emergency setting, flank pain commonly leads to a noncontrast CT despite a significant percentage of patients having alternative diagnoses, often difficult to characterize without contrast. We investigated the combined utility of urinalysis and history of urolithiasis in identifying patients who are unlikely to have urolithiasis and may benefit from a contrast-enhanced study. METHODS: Retrospective review of 350 patients from May 2013 to May 2016 was performed for patients in the emergency department with renal colic that underwent noncontrast CT and urinalysis testing. RESULTS: Urolithiasis was present in 282 of the 350 patients reviewed (81%), of which 175 (62%) had an obstructing calculus. RBC-positive urinalysis was present in 231 patients with calculi on CT (sensitivity 82%). Patient history of urolithiasis plus urinalysis had a sensitivity of 94% for detecting calculi. Thirty-five patients (10%) had alternative diagnoses, 33 of which were in patients without obstructing calculi. Sixty-seven patients underwent noncontrast CT despite no history of urolithiasis and a negative urinalysis, 10 of which (15%) had alternative diagnoses. Only three cases in this subset (4%) had nonobstructing 1-2-mm calculi, potentially missed with contrast. In this subset, the projected proportion of optimally characterized cases with intravenous contrast is 96%, compared to 85% without contrast (p = .03). DISCUSSION: Given the high combined sensitivity of urinalysis and patient history (94%), this simple analysis can confidently direct clinicians to a contrast-enhanced CT in "rule-out" cases of flank pain in patients with a negative history and negative urinalysis, particularly given that 15% of these patients had alternative diagnoses.

Acute nontraumatic splenic infarctions at a tertiary-care center: causes and predisposing factors in 123 patients.

Acute splenic infarcts classically present with left upper quadrant pain, but may be discovered incidentally in many hospitalized patients with otherwise vague complaints. The purpose of our study was to document causes or predisposing conditions in patients found to have acute splenic infarctions on imaging. Following IRB approval, a retrospective review of an imaging database from May 2008 to May 2015 was performed for cases of acute splenic infarctions. The electronic medical record was then reviewed for potential predisposing factors or known causes. Specific note was made of cases with active malignancy, vascular disorders, or inflammatory conditions with an increased risk of vasculopathy. Echocardiogram and electrocardiogram results were reviewed when available. One hundred twenty-three patients with acute splenic infarcts were identified, 65 female and 58 male. The average age was 57 years (range of 22 to 88). Active malignancy was present in 40 patients or 33 %. The most common malignancy in patient with nontraumatic splenic infarctions was pancreatic cancer, present in 16 patients (13 %). In these patients, splenic infarction was due to direct invasion of vessels in the splenic hilum. Acute pancreatitis (severe) was directly responsible for splenic infarction in seven additional cases (6 %). Additional visceral infarcts were present in 18 patients (15 %), most commonly concomitant hepatic or renal infarcts. Documented atrial fibrillation was present in 12 patients, but only 2 cases of left-sided cardiac thrombi were seen on CT (1 atrial, and 1 ventricular thrombus). Eight cases of endocarditis with valvular vegetations were documented on echocardiography (7 %). Splenomegaly was present in 32 patients (26 %) with acute splenic infarction. In patients with nontraumatic splenic infarctions, there appears to be a relatively high association with active malignancy (up to a third of patients). Pancreatic disorders, malignant and inflammatory, also appear to be an important cause of splenic infarction, presumably due to the close proximity of the pancreas to the splenic vessels.

Erratum to: Identifying decreased peristalsis of abnormal small bowel segments in Crohn's disease using cine MR enterography: the frozen bowel sign.

PURPOSE: The purpose of this study was to evaluate whether affected bowel in Crohn's disease patients can be identified by observing decreased peristalsis (frozen bowel sign) using cine balanced steady-state free precession (cine BSSFP) images. MATERIALS AND METHODS: 5 radiologists independently reviewed cine BSSFP sequences from randomized MR Enterography (MRE) exams for 30 normal and 30 Crohn's disease patients, graded overall small bowel peristalsis from slowest to fastest, and graded peristalsis for the most abnormal small bowel segment. Sensitivity and specificity of the frozen bowel sign for diagnosing Crohn's disease were calculated. T tests of the peristalsis difference between abnormal segments and overall small bowel were conducted. RESULTS: For 5 readers, the sensitivity and specificity of cine BSSFP of the frozen bowel sign for diagnosing Crohn's disease ranged from 70% to 100% and 87% to 100%, respectively. There were significant differences in peristalsis between abnormal small bowel segments and the overall small bowel for Crohn's patients, but not in the overall small bowel between normal-MRE patients and Crohn's disease patients. CONCLUSION: Abnormal Crohn's small bowel segments have significantly decreased peristalsis compared to normal small bowel, which can be identified using cine BSSFP sequences as the frozen bowel sign.

Identifying decreased peristalsis of abnormal small bowel segments in Crohn's disease using cine MR enterography: the frozen bowel sign.

PURPOSE: The purpose of this study was to evaluate whether affected bowel in Crohn's disease patients can be identified by observing decreased peristalsis (frozen bowel sign) using cine balanced steady-state free precession (cine BSSFP) images. MATERIALS AND METHODS: 5 radiologists independently reviewed cine BSSFP sequences from randomized MR Enterography (MRE) exams for 30 normal and 30 Crohn's disease patients, graded overall small bowel peristalsis from slowest to fastest, and graded peristalsis for the most abnormal small bowel segment. Sensitivity and specificity of the frozen bowel sign for diagnosing Crohn's disease were calculated. T tests of the peristalsis difference between abnormal segments and overall small bowel were conducted. RESULTS: For 5 readers, the sensitivity and specificity of cine BSSFP of the frozen bowel sign for diagnosing Crohn's disease ranged from 70% to 100% and 87% to 100%, respectively. There were significant differences in peristalsis between abnormal small bowel segments and the overall small bowel for Crohn's patients, but not in the overall small bowel between normal-MRE patients and Crohn's disease patients. CONCLUSION: Abnormal Crohn's small bowel segments have significantly decreased peristalsis compared to normal small bowel, which can be identified using cine BSSFP sequences as the frozen bowel sign.

"My attending really wants it!" Manual clinical decision support adjudicating the "better look" inpatient MRI at an academic medical center.

OBJECTIVE: MRI utilization in the United States is relatively higher than in other parts of the world and inpatient MRI utilization is particularly difficult to manage given the lack of direct reimbursement. Body MRI studies present an opportunity to reduce inpatient MRI utilization since they are generally the least emergent. Our objective was to use a targeted questionnaire to probe the necessity of inpatient body MRI orders and present an opportunity to either cancel them or transition them to the outpatient realm METHODS: A 9-item questionnaire was devised asking questions about the urgency of the inpatient MRI order including the urgent management question, an inpatient procedure or whether it was recommended by a consultant. Peer-to-peer discussion walking through each of the questions was conducted by radiology housestaff with the ordering clinicians and responses recorded. RESULTS: 845 recorded responses reported a lack of specific clinical question in 23.9% of orders, 68.9% were recommended by a non-radiology consulting service and 16.1% were recommended by radiology studies. 17.0% orders were felt to be outpatient appropriate and 23.3% were considered possibly appropriate for the outpatient setting. 3.9% were canceled and 4.9% were transitioned to outpatient orders. DISCUSSION: Engaging in a focused discussion about the urgency and appropriateness of an inpatient MRI body order following a list of scripted questions has the potential to reduce utilization. This approach also highlights the relatively high rate of indication uncertainty among ordering clinicians and the central role of consultants in prompting orders.

Emphysematous pyelonephritis necessitating bilateral radical nephrectomy: A case report and literature review.

Emphysematous pyelonephritis (EPN) is a severe, acute necrotizing infection of the kidney with gas accumulation in the renal parenchyma, collecting ducts, and/or perirenal tissue. We report a case of EPN in a 66 year-old male with uncontrolled diabetes mellitus (DM), urinary tract infection and septic shock necessitating emergent bilateral radical nephrectomy. Morphologically, the kidney parenchyma revealed severe acute bacterial pyelonephritis with extensive abscesses, gas cysts, necrosis and foci of infarctions. The uninvolved background cortex parenchyma exhibited diabetic nephropathy (DN), Class IIB. Post-operatively, the patient remained dialysis-dependent with multiple re-admissions for recurrent multi-drug resistant E. coli pyocystitis, anemia and urinary retention.

The pre-operative and post-operative imaging appearances of urethral strictures and surgical techniques.

Urethral strictures arise from a variety of etiologies, most commonly either iatrogenic or inflammatory in the anterior urethra and iatrogenic/surgical or traumatic etiologies in the posterior urethra. Diagnosis and treatment planning depend on urethrography, usually performed with a combination of retrograde urethrography (RUG) and voiding cystourethrography (VCUG) to evaluate the anterior and posterior urethra, respectively. While this is most commonly performed fluoroscopically, sonographic urethrography is an alternative, although at the expense of the posterior urethra, it is only visualized using a transrectal approach. In addition to understand urethral anatomy, familiarity with normal periurethral structures is necessary to avoid misdiagnosis, such as Cowper's ducts, the glands of Littré, and the prostatic and ejaculatory ducts. Surgical management depends on the stricture location, length, and number and options range from balloon dilatation to endoscopic urethrotomy to anastomotic and substitution urethrotomy. Postprocedural management includes urethrography to identify potential complications including urethral leak, graft failure, and stricture recurrence.

Comparing the productivity of teaching and non-teaching workflow models in an academic abdominal imaging division.

PURPOSE: To evaluate the productivity difference between teaching and non-teaching workflow models in an abdominal imaging division in an academic radiology department. METHODS AND MATERIALS: RVU data were compiled for six faculty members from the abdominal imaging division over a six-month period. Modalities included ultrasound and CT of the abdomen and pelvis. The relative RVU productivity for faculty members by workflow was compared individually and the composite data for the workflow models were compared. The relative RVU productivity for each faculty member was compared individually and in aggregate to study the effect of the workflow models on RVUs using factorial ANOVA. Turnaround times (TAT) were compared for each attending under both models. TAT data were analyzed using paired t-tests with Bonferroni corrections for multiple comparisons. RESULTS: Daily RVU data from 387 instances were analyzed. Daily RVUs for faculty members ranged from 23.5 ± 2.3 (mean ± standard error) to 46.2 ± 2.4 with non-teaching and from 29.8 ± 2.2 to 54.4 ± 2.7 with teaching workflow, respectively. There was a significant main effect of the workflow model on RVU productivity (p < 0.05). A significant increase of 27.8% in RVUs was noted with teaching workflow (42.8 ± 0.9) relative to non-teaching workflow (33.5 ± 1.7; p < 0.05). Teaching workflow resulted in significantly higher view-final and complete-final TATs (593 ± 112 min, mean ± SE and 841 ± 96 min, mean ± SE, respectively) compared to the non-teaching workflow (385 ± 124 min). CONCLUSION: Teaching workflow improves abdominal imaging productivity with an increase in report turnaround times.

Exophytic renal masses: angular interface with renal parenchyma for distinguishing benign from malignant lesions at MR imaging.

PURPOSE: To retrospectively determine whether benign exophytic renal masses can be distinguished from renal cell carcinoma (RCC) on the basis of angular interface at single-shot fast spin-echo (SE) T2-weighted magnetic resonance (MR) imaging. MATERIALS AND METHODS: This retrospective study was compliant with HIPAA and was approved by the institutional review board. Patient informed consent was waived. A total of 162 exophytic (2 cm or greater) renal masses in 152 patients (103 men, 49 women; mean age, 58 years; age range, 23-85 years) were included. Two radiologists independently recorded the mass size and angular interface on single-shot fast SE T2-weighted MR images. Surgical pathologic report and MR follow-up were used as reference standards. Logistic regression analysis was used to examine the usefulness of these variables for differentiating benign masses from RCCs. Diagnostic performance was analyzed by comparing values for area under receiver operating characteristic curve (A(z)). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of angular interface for diagnosing benign masses were calculated. Reader agreement was assessed with kappa-weighted statistics and intraclass correlation coefficients (ICCs). RESULTS: Of 162 masses, 65 were benign, and 97 were RCCs. The sensitivity, specificity, PPV, NPV, and A(z) of angular interface for diagnosing benign masses were 78%, 100%, 100%, 87%, and 0.813, respectively. Angular interface (P < .001) was a significant predictor of benign renal mass but mass size (P = .66) was not. There was almost perfect interobserver agreement for mass size (ICC = 0.96) and angular interface (kappa = 0.91). CONCLUSION: The presence of an angular interface with the renal parenchyma at single-shot fast SE T2-weighted MR imaging is a strong predictor of benignity in an exophytic renal mass 2 cm or greater in diameter with high specificity and diagnostic accuracy.

Optimizing abdominal MR imaging: approaches to common problems.

Abdominal magnetic resonance (MR) imaging involves many challenges and is complicated by physiologic motion not encountered to the same degree in other regions of the body. Problems that uniquely affect abdominal MR imaging include motion artifact (from respiratory, cardiac, gastrointestinal, and voluntary movement), susceptibility artifact, conductive and dielectric effects, and wraparound artifact. Techniques to minimize these artifacts often need to be addressed within the time constraints of a single breath hold. Patient motion during image acquisition is minimized by using physical restraint, respiratory gating, and reduction of acquisition time. Correction of motion-induced dephasing (through gradient moment nulling), signal averaging, and suppression of signal in moving structures all address unavoidable motion (eg, cardiac pulsation). Acquisition time is minimized by obtaining fewer phase-encoding steps, decreasing repetition time, and increasing efficiency with use of parallel imaging and multiecho acquisitions. Adjusting the echo time does not directly affect scanning time, but it does allow more time for section sampling per repetition time interval in multisection acquisitions by means of closer echo spacing and it plays a pivotal role in optimizing image quality. Familiarity with basic MR imaging principles and the ability to minimize the effects of motion and other artifacts are essential to optimizing abdominal MR imaging protocols and improving efficiency.

Shedding the Light on the Off-Hours Problem in Radiology.

Diagnostic error and diagnostic delays in health care are widespread. This article outlines an improvement effort targeting weekday evening inpatient radiology delays through staffing changes replacing trainees with faculty-trainee team coverage, pushing faculty coverage from 4 pm to 8 pm. Order-report turnaround times (TATs), critical findings TATs for pneumothorax and intracranial hemorrhage (ICH), and percentage meeting target were compared pre and post implementation for the 4 to 8 pm time frame using the Mann-Whitney U and χ2 tests, respectively. Stakeholder surveys assessed patient safety, morale, education, and operational efficiency. Median TATs (minutes) improved: X-rays 906 to 112, computed tomography 994 to 84, magnetic resonance imaging 1172 to 233, and ultrasound 88 to 58. Median critical findings TATs (minutes) improved from 853 to 30 and 112 to 22 for pneumothorax and ICH, respectively, and the percentage meeting target improved from 45% to 65%. Survey results reported perceived improvement in patient safety, education, and operational efficiency and no impact on morale.

Spatial distribution of biopsy cores and the detection of intra-lesion pathologic heterogeneity.

OBJECTIVES: The objective of this study was to determine if spatial distribution of multiparametric magnetic resonance imaging-transrectal ultrasound (mpMRI-TRUS) fusion biopsy cores to the index lesion reveals trends in the detection of intra-lesion Gleason heterogeneity and a more optimal prostate biopsy strategy. METHODS: Index lesion was the lesion with longest diameter on T2-weighted (T2W)-MRI. In cohort 1, fusion biopsy cores biopsies were taken in areas in the center of the target as well as 1 cm laterally on each side. For cohort 2, targeted biopsies were taken from the center of the lesion only. Heterogeneity was defined as difference in maximum Gleason score obtained from fusion cores in the center of the index lesion versus cores obtained from the periphery (cohort 1), or any difference in maximum Gleason score obtained from fusion cores targeted to the index lesion (cohort 2) compared with systematic 12 cores TRUS biopsy. RESULTS: Ninety-nine consecutive patients (35 and 64 in cohorts 1 and 2, respectively) with median age (SD) and prostate-specific antigen (PSA) of 66.9 (±5.9) and 9.7 (±8.2) respectively, were included. Age, PSA, Prostate Imaging Reporting and Data System (PI-RADS) score, and preoperative MRI lesion size were not significantly different between cohorts. Gleason heterogeneity was observed at a significantly higher rate in cohort 1 versus cohort 2 (58% versus 24%; p = 0.041). In cohort 1, cores obtained from the center of the lesion had higher Gleason score than cores obtained from the periphery of the targeted lesion in 57% of cases. CONCLUSIONS: We demonstrate that there is observable tumor heterogeneity in biopsy specimens, and that increased number of cores, as well as cores focused on the center and periphery of the largest lesion in the prostate, provide more comprehensive diagnostic information about the patient's clinical risk category than taking nonspecific cores targeted within the tumor.

Outpatient facility-based order variation in combined imaging.

OBJECTIVE: Combined computed tomography (CT) occurs when one anatomical area is simultaneously imaged both without and with contrast, or two overlapping anatomical areas are imaged concurrently. While this has been studied in a Traditional Medicare population, it has not been studied in other populations subject to prior authorization. This study explores between-facility variation in ordering and receiving orders to render combined CT in a mixed commercial and Medicare Advantage population. METHODS: Orders for CT abdomen (without/with contrast), CT thorax (without/with contrast), and concurrent CT brain and sinus authorized by a prior authorization company from 2013-2017, pertaining to patients with commercial or Medicare Advantage health plans from one national insurer, were extracted. Orders were issued and rendered by both hospitals and nonhospitals. The analysis was performed separately for each anatomical area in two ways: orders were grouped by ordering facility, and by designated rendering facility. For each facility, the ratio of combined to total orders was calculated, and analysis of variance was used to determine whether there were significant differences in this rate by year. The association between health plan type and combined imaging rates was assessed. RESULTS: Combined rates [ratio±standard deviation] for abdomen, thorax, and brain/sinus were 0.306±0.246, 0.089±0.142, and 0.002±0.01 respectively when the analysis was conducted according to ordering facility, and 0.311±0.178, 0.096±0.113, and 0.001±0.006 when the analysis was conducted according to designated rendering facility. Combined CT abdomen and CT thorax rates decreased monotonically from 2013 to 2017, decreases that were significant (P < .01) regardless of whether orders were grouped by ordering or rendering facility. Combined CT abdomen and CT thorax rates significantly differed between orders pertaining to people with commercial and Medicare Advantage plans. DISCUSSION: Variability was greater when orders were grouped by ordering facility, rather than rendering facility. Health plan type may influence whether a patient receives combined CT.

Contrast-Enhanced Chest Computed Tomography Reveals Treatable Causes of Cerebral Abscesses in Patients without Antecedent Surgery or Trauma.

OBJECTIVE: Brain abscesses cause substantial morbidity and mortality even after appropriate therapy, and no underlying cause is found in 25% of cases. We investigated the added utility of contrast-enhanced chest computed tomography (CT) in the diagnostic work-up of patients presenting with cerebral abscesses and no history or prior trauma or cranial surgery. METHODS: All patients presenting to a single institution with a surgically proven brain abscess were reviewed. Concurrent contrast-enhanced chest CT imaging results were reviewed when available to identify treatable predisposing causes of intracranial suppuration. RESULTS: This study included 31 patients with biopsy-proven abscesses. Multiple abscesses were present in 8 patients (26%). Contrast-enhanced CT was performed in 15 patients (48%). Of these 15 patients, 2 had pulmonary arteriovenous malformations, 1 had an intrapulmonary shunt, and 3 had empyemas. Definitive therapy for the chest findings was provided to 6 of the 15 patients (40%). In the remaining 9 patients, 3 had pulmonary abscesses, for which diagnostic aspiration was requested. Another patient had an incidental pulmonary embolism, resulting in same-day placement of an inferior vena caval filter (not included in chest analysis, given that the finding was incidental). CONCLUSIONS: Contrast-enhanced chest CT is useful for identifying treatable causes of cerebral abscesses in patients with a cerebral abscess and no history of surgery or trauma.

Interpreting body MRI cases: what you need to know to get started.

Interpreting body MRI cases can seem overwhelming to an uninitiated radiologist. The standard study includes a variety of pulse sequences, the names of which vary depending on the MR vendor. Pulse sequences may be displayed haphazardly on the picture archiving and communication system (PACS), frequently not synchronized with the imaging protocol. Adding to the complexity is the use of different gadolinium-based contrast agents, which may affect the timing and diagnostic yield of each sequence. The following introductory primer for interpreting body MRI cases is meant to create a basic framework for efficiently reviewing body MRI cases to provide high quality interpretations, fully utilizing the diagnostic information of the modality. There are 4 components that need to be mastered when interpreting body MRI cases including: (1) recognizing the key sequences in a basic body MRI protocol, (2) learning how to best display the key pulse sequences on PACS, (3) understanding the technique and clinical utility of each sequence and learning how to utilize sequences to be an "MR Pathologist", and (4) understanding the key features of the different gadolinium based contrast agents.

Hepatocellular carcinoma after locoregional therapy: Magnetic resonance imaging findings in falsely negative exams.

AIM: To elucidate causes for false negative magnetic resonance imaging (MRI) exams by identifying imaging characteristics that predict viable hepatocellular carcinoma (HCC) in lesions previously treated with locoregional therapy when obvious findings of recurrence are absent. METHODS: This retrospective institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study included patients who underwent liver transplantation at our center between 1/1/2000 and 12/31/2012 after being treated for HCC with locoregional therapy. All selected patients had a contrast-enhanced MRI after locoregional therapy within 90 d of transplant that was prospectively interpreted as without evidence of residual or recurrent tumor. Retrospectively, 2 radiologists, blinded to clinical and pathological data, independently reviewed the pre-transplant MRIs for 7 imaging features. Liver explant histopathology provided the reference standard, with clinically significant tumor defined as viable tumor ≥ 1.0 cm in maximum dimension. Fisher's exact test was first performed to identify significant imaging features. RESULTS: Inclusion criteria selected for 42 patients with 65 treated lesions. Fourteen of 42 patients (33%) and 16 of 65 treated lesions (25%) had clinically significant viable tumor on explant histology. None of the 7 imaging findings examined could reliably and reproducibly determine which treated lesion had viable tumor when the exam had been prospectively read as without evidence of viable HCC. CONCLUSION: After locoregional therapy some treated lesions that do not demonstrate any MRI evidence of HCC will contain viable tumor. As such even patients with a negative MRI following treatment should receive regular short-term imaging surveillance because some have occult viable tumor. The possibility of occult tumor should be a consideration when contemplating any action which might delay liver transplant.

Research Challenges and Opportunities for Clinically Oriented Academic Radiology Departments.

Between 2004 and 2012, US funding for the biomedical sciences decreased to historic lows. Health-related research was crippled by receiving only 1/20th of overall federal scientific funding. Despite the current funding climate, there is increased pressure on academic radiology programs to establish productive research programs. Whereas larger programs have resources that can be utilized at their institutions, small to medium-sized programs often struggle with lack of infrastructure and support. To address these concerns, the Association of University Radiologists' Radiology Research Alliance developed a task force to explore any untapped research productivity potential in these smaller radiology departments. We conducted an online survey of faculty at smaller clinically funded programs and found that while they were interested in doing research and felt it was important to the success of the field, barriers such as lack of resources and time were proving difficult to overcome. One potential solution proposed by this task force is a collaborative structured research model in which multiple participants from multiple institutions come together in well-defined roles that allow for an equitable distribution of research tasks and pooling of resources and expertise. Under this model, smaller programs will have an opportunity to share their unique perspective on how to address research topics and make a measureable impact on the field of radiology as a whole. Through a health services focus, projects are more likely to succeed in the context of limited funding and infrastructure while simultaneously providing value to the field.