Evaluation of 18 CT signs in diagnosing cecal volvulus: a multi-reader retrospective study.

PURPOSE: To assess the diagnostic performance and reliability of 18 CT signs to diagnose cecal volvulus, a surgical emergency, versus a group of non-volvulus mimickers. MATERIALS AND METHODS: Four radiologists retrospectively and independently assessed 18 CT signs in 191 patients with cecal volvulus (n = 63) or a non-volvulus control group ((n = 128), including cecal bascule (n = 19), mobile cecum (n = 95), and colonic pseudo-obstruction (n = 14)) at a single institution from 2013 to 2021. Fleiss' kappa coefficient was used to assess inter-reader agreement. For diagnostic performance metrics, we assessed sensitivity, specificity, and positive and negative predictive values. For predictive performance, all 18 signs were included in bivariate and stepwise lasso multivariate logistic regression models to diagnose cecal volvulus. Performance was assessed by ROC curves. RESULTS: 191 patients (mean age: 63 years +/- 15.5 [SD]; 135 women) were included in the study. Nine of the 18 CT signs of cecal volvulus demonstrated good or better (> 0.6) inter-reader agreement. Individual CT signs with sensitivity, specificity, positive and negative predictive values all above 70% for diagnosing cecal volvulus were transition point, bird beak, and X-marks-the-spot. A lasso regression model determined four CT features: transition point, bird beak, coffee bean, and whirl had excellent prediction (AUC = .979) for cecal volvulus if all present. CONCLUSION: CT signs for cecal volvulus that have high sensitivity and specificity include: transition point, bird beak, and X-marks-the-spot and were reliable in distinguishing non-volvulus mimickers. If the following four features were present: transition point, bird beak, coffee bean, and whirl, there was excellent prediction (AUC = .979) for cecal volvulus.

The utility of [18F]Fluciclovine PET/CT in Evaluating Nonmetastatic Castrate-Resistant Prostate Cancer Patients (nmCRPCp): diagnostic performance and impact on management.

OBJECTIVE: To evaluate the role of [18F]Fluciclovine PET/CT scan in restaging nmCRPCp and its impact on management. METHODS AND MATERIALS: This retrospective study included all patients with nonmetastatic castrate-resistant prostate cancer, who underwent [18F]Fluciclovine PET/CT scans for restaging who had concern for disease progression. Two radiologists independently reviewed the PET/CT studies, assigned an overall impression, and reported the site and number of radiotracer activities in consensus and impact on management was recorded. Available tissue diagnosis and/or six-month clinical and imaging follow-up were used as reference standards. RESULTS: Thirty-five patients were included in this study. At least one lesion was detected in 73% (26/35) of the scans. Management changed in 71% (25/35) of patients, (22 positives and three negative scans). 26.9% (7/26) of patients were found to have an oligometastatic disease. Based on the reference standards, the diagnostic performance of [18F]Fluciclovine PET/CT in detecting recurrence in nmCRCP has 86%, sensitivity, 83% specificity, 96.1% PPV, and 55.5% NPV. There was no relationship between the Gleason score and a positive PET/CT scan in our patient population. CONCLUSION: Detecting the source of recurrence is challenging in nmCRCP patients when conventional imaging fails. Given the high PPV, sensitivity, and specificity, [18F]Fluciclovine PET/CT can be used instead of conventional imaging as a first-line choice due to its superiority over bone scan and added value of detecting soft tissue metastasis regardless of the initial Gleason score. ADVANCES IN KNOWLEDGE: The study highlights the added value of [18F]Fluciclovine PET/CT in detecting soft tissue metastasis regardless of the initial Gleason score, which is not possible with conventional imaging such as bone scans.The study highlights the potential role of [18F]Fluciclovine PET/CT guiding management change for nonmetastatic castrate-resistant prostate cancer patients, particularly those with oligometastatic disease.

Teaching with Technology-Matching Pedagogy with Purpose in Radiology Education.

The response to pandemic-related teaching disruption has revealed dynamic levels of learning and teaching flexibility and rapid technology adoption of radiology educators and trainees. Shutdowns and distancing requirements accelerated the adoption of technology as an educational tool, in some instances supplanting in-person education entirely. Despite the limitations of remote interaction, many educational advantages were recognized that can be leveraged in developing distance learning paradigms. The specific strategies employed should match modern learning science, enabling both students and educators to mutually grow as lifelong learners. As panel members of the "COVID: Faculty perspective" Task Force of the Association of University Radiologists Radiology Research Alliance, we present a review of key learning principles which educators can use to identify techniques that enhance resident learning and present an organized framework for applying technology-aided techniques aligned with modern learning principles. Our aim is to facilitate the purposeful integration of learning tools into the training environment by matching these tools to established educational frameworks. With these frameworks in mind, radiology educators have the opportunity to re-think the balance between traditional curricular design and modern digital teaching tools and models.

A Framework for Harmonization of Radiomics Data for Multicenter Studies and Clinical Trials.

PURPOSE: Variability in computed tomography images intrinsic to individual scanners limits the application of radiomics in clinical and research settings. The development of reproducible and generalizable radiomics-based models to assess lesions requires harmonization of data. The purpose of this study was to develop, test, and analyze the efficacy of a radiomics data harmonization model. MATERIALS AND METHODS: Radiomic features from biopsy-proven untreated hepatic metastasis (N = 380) acquired from 167 unique patients with pancreatic, colon, and breast cancers were analyzed. Radiomic features from volume-match 551 samples of normal liver tissue and 188 hepatic cysts were included as references. A novel linear mixed effect model was used to identify effects associated with lesion size, tissue type, and scanner model. Six separate machine learning models were then used to test the effectiveness of radiomic feature harmonization using multivariate analysis. RESULTS: Proposed model identifies and removes scanner-associated effects while preserving cancer-specific functional dependence of radiomic features on the tumor size. Data harmonization improves the performance of classification models by reducing the scanner-associated variability. For example, the multiclass logistic regression model, LogitBoost, demonstrated the improvement in sensitivity in the range from 15% to 40% for each type of liver metastasis, whereas the overall model accuracy and the kappa coefficient increased by 5% and 8% accordingly. CONCLUSION: The model removed scanner-associated effects while preserving cancer-specific functional dependence of radiomic features.

Utilizing CT to identify clinically significant biliary dilatation in symptomatic post-cholecystectomy patients: when should we be worried?

PURPOSE: To determine a reliable threshold common duct diameter on CT, in combination with other ancillary CT and clinical parameters, at which the likelihood of pathology requiring further imaging or intervention is increased in post-cholecystectomy patients. METHODS: In this IRB approved retrospective study, two attending radiologists independently reviewed CT imaging for 118 post-cholecystectomy patients, who were subsequently evaluated with MRCP, ERCP, or EUS, prompted by findings on the CT and clinical status. Measurements of the common duct (CD) were obtained at the porta hepatis, distal duct, and point of maximal dilation on axial and coronal CT scans. Patients were grouped by whether they required intervention after follow-up imaging. Pertinent baseline lab values and patient demographics were reviewed. RESULTS: Of the 118 post-cholecystectomy patients, 38 patients (31%) required intervention, and 80 patients (69%) did not require intervention after follow-up imaging. For both readers, axial and coronal CD diameters were significantly higher in the 'intervention required' vs 'no intervention' groups at all locations (p value < 0.05). There was good to excellent inter-reader agreement at all locations (ICC 0.68-0.92). Pertinent baseline lab values including AST (p = 0.043), ALT (p = 0.001), alkaline phosphatase (p = 0.0001), direct bilirubin (p = 0.011), total bilirubin (p = 0.028), and WBC (p = 0.043) were significantly higher in the 'intervention required' group. CD thresholds of 8 mm yielded the highest sensitivities (76-95%), and CD thresholds of 12 mm yielded the highest specificities (65-78%). CD combined with bilirubin levels increased sensitivity and specificity, compared to using either feature alone. CONCLUSION: Dilated CD on CT combined with bilirubin levels increases the sensitivity and specificity for identifying patients needing intervention. We recommend that a post-cholecystectomy patient who presents with a CD diameter > 10 mm on CT and elevated bilirubin levels should undergo further clinical and imaging follow-up.

Association of CT findings in patients with hemoperitoneum due to ruptured ovarian cysts with subsequent intervention.

PURPOSE: Hemoperitoneum caused by ovarian cyst rupture may necessitate intervention. The literature is lacking in descriptions of CT findings that help guide patient management. The purpose of this study is to consider CT findings associated with a need for intervention (surgical or interventional radiology management) versus conservative treatment (observation, pain management, and blood transfusions). METHODS: Two radiologists retrospectively and independently reviewed 103 CTs of pre-menopausal women who presented with acute hemoperitoneum related to ruptured ovarian cysts between January 2010 and January 2019. The following imaging features were assessed: ovarian cyst characteristics, sentinel clot, contrast extravasation, and hemoperitoneum size. Findings were correlated with patient demographics, clinical parameters, and management with surgery/interventional radiology procedure (intervention group) versus conservative management (conservative group). RESULTS: Of the 103 patients with hemoperitoneum from cyst rupture, 16% (n = 16) required intervention, and 84% underwent conservative treatment (n = 87). Length of stay (p = .008) was higher in the intervention group. Statistically significant CT findings in the intervention versus conservative group included (p-value reader 1/p-value reader 2) greatest AP dimension of hemoperitoneum (p = .001/p = 0.02), posterior cul-de-sac AP dimension (p = 0.03/p = .006), total cul-de-sac AP dimension (p = .002/p = .007), and number of spaces with hemoperitoneum (p = .01/p = .02). There was good to excellent inter-reader agreement for these findings (ICC 0.68-0.91). Active contrast extravasation was significant for one reader (p = .02) with poor inter-reader agreement (ICC 0.36). In utilizing ROC curves, thresholds of 107 mm (greatest axial AP dimension of hemoperitoneum) yielded a sensitivity and specificity of 0.81 and 0.62 for reader 1 and 0.69 and 0.55 for reader 2; 45 mm (posterior cul-de-sac AP dimension) yielded a sensitivity and specificity of 0.75 and 0.63 for reader 1 and 0.94 and 0.49 for reader 2; 70 mm (total cul-de-sac AP dimension) yielded a sensitivity and specificity of 0.75 and 0.64 for reader 1 and 0.75 and 0.50 for reader 2; and greater than 5 spaces yielded a sensitivity and specificity of 0.75 and 0.58 for reader 1 and 0.69 and 0.70 for reader 2. CONCLUSION: CT findings associated with intervention in hemoperitoneum due to ovarian cyst rupture include size of hemoperitoneum, number of abdominopelvic spaces with hemoperitoneum, and contrast extravasation.

Role of hepatic metastatic lesion size on inter-reader reproducibility of CT-based radiomics features.

OBJECTIVES: To evaluate the effect of hepatic metastatic lesion size on inter-reader reproducibility of CT-based 2D radiomics imaging features. METHODS: Computerized tomography (CT) scans of 59 liver metastases from 34 patients with colorectal cancer were evaluated. Image segmentation was performed manually by three readers blinded to each other's results. For each radiomics feature, we created two datasets by sorting measurements according to size, i.e., (i) from the smallest to the largest lesion and (ii) from the largest to the smallest lesion. The Lin concordance correlation coefficient (CCC) was employed to analyze the reproducibility of radiomics features. In particular, the CCC was computed as a function of a number of elements in the dataset, by gradually adding lesions from each sorted dataset. To evaluate the effect of lesion size, we analyzed the difference between these two functions thus assessing the contribution of small and large lesions into the reproducibility of radiomics features. RESULTS: Inter-reader reproducibility of CT-based 2D radiomics features assessed using Lin's CCC demonstrates tumor-size dependence. For example, the Lin CCC for GLCM contrast equals 0.88 (95% C.I. 0.84 to 0.92, p < 0.003) and could change by an additional + / - 0.06 depending on the presence of large or small lesions. CONCLUSIONS: Groups of "large" and "small" lesions show different inter-reader reproducibility. The inter-reader reproducibility from the mixed group consisting of "large" and "small" lesions depends on the lesion-size distribution and can vary widely. This finding could partially explain variability in reproducibility of radiomics features in the literature. KEY POINTS: • Groups of "large" and "small" lesions show different inter-reader reproducibility. • The inter-reader reproducibility from the mixed group consisting of "large" and "small" lesions depends on the lesion-size distribution.

Role of Ergonomic Improvements in Decreasing Repetitive Stress Injuries and Promoting Well-Being in a Radiology Department.

RATIONALE AND OBJECTIVES: To determine if ergonomic improvements in a radiology department can decrease repetitive stress injuries (RSIs), advance ergonomics knowledge, and improve well-being. MATERIALS AND METHODS: Radiologists in an academic institution were surveyed regarding physician wellness, workstations, RSIs, and ergonomics knowledge before and after interventions over 1 year. Interventions included committee formation, education, wrist pads and wireless mice, broken table and chair replacement, and cord organization. Mann-Whitney U test was used for analysis. RESULTS: Survey response was 40% preinterventions (59/147), and 42% (66/157) postinterventions. Preinterventions, of radiologists with RSI history, 17/40 (42%) reported the RSI caused symptoms which can lead to burnout, and 15/40 (37%) responded their RSI made them think about leaving their job. Twenty-three of 59 (39%) radiologists had an active RSI preinterventions. Postinterventions, 9/25 (36%) RSI resolved, 13/25 (52%) RSI improved, and 3/25 (12%) RSI did not improve. RSI improvements were attributed to ergonomic interventions in 19/25 (76%) and therapy in 2/25 (8%). Radiologists who thought their workstation was designed with well-being in mind increased from 9/59 (15%) to 52/64 (81%). The percentage of radiologists knowing little or nothing about ergonomics decreased from 15/59 (25%) to 5/64 (8%). After ergonomics interventions, more radiologists thought the administration cared about safety and ergonomics, equipment was distributed fairly, and radiologists had the ability to ask for equipment (p < .01). Fifty-three of 64 (83%) of radiologists after interventions said improving workstation ergonomic design contributed to well-being. CONCLUSION: Ergonomic improvements in radiology can decrease RSIs, advance ergonomics knowledge, and improve well-being.

Evolution of Radioembolization in Treatment of Hepatocellular Carcinoma: A Pictorial Review.

Transarterial radioembolization (TARE) with yttrium 90 has increasingly been performed to treat hepatocellular carcinoma (HCC). TARE was historically used as a palliative lobar therapy for patients with advanced HCC beyond surgical options, ablation, or transarterial chemoembolization, but recent advancements have led to its application across the Barcelona Clinic Liver Cancer staging paradigm. Newer techniques, termed radiation lobectomy and radiation segmentectomy, are being performed before liver resection to facilitate hypertrophy of the future liver remnant, before liver transplant to bridge or downstage to transplant, or as a definite curative treatment. Imaging assessment of therapeutic response to TARE is challenging as the intent of TARE is to deliver local high-dose radiation to tumors through microembolic microspheres, preserving blood flow to promote radiation injury to the tumor. Because of the microembolic nature, early imaging assessment after TARE cannot rely solely on changes in size. Knowledge of the evolving methods of TARE along with the tools to assess posttreatment imaging and response is essential to optimize TARE as a therapeutic option for patients with HCC. ©RSNA, 2021.

Review of Artificial Intelligence Training Tools and Courses for Radiologists.

Artificial intelligence (AI) systems play an increasingly important role in all parts of the imaging chain, from image creation to image interpretation to report generation. In order to responsibly manage radiology AI systems and make informed purchase decisions about them, radiologists must understand the underlying principles of AI. Our task force was formed by the Radiology Research Alliance (RRA) of the Association of University Radiologists to identify and summarize a curated list of current educational materials available for radiologists.

Optimizing detection of postoperative leaks on upper gastrointestinal fluoroscopy: a step-by-step guide.

Postoperative leaks after gastrointestinal surgery are important to identify to decrease patient morbidity and mortality. Fluoroscopic studies are commonly employed to detect postoperative leak. While the literature addresses the sensitivity and specificity of these examinations, there is generally a lack of description of the fluoroscopic technique itself and there may be variability between radiologists in how these studies are performed. It is important to balance a standardized fluoroscopy protocol while tailoring the exam for each surgical and patient situation. Here we will briefly review common postoperative anatomy in the upper gastrointestinal tract, propose fluoroscopic techniques to improve postoperative leak detection, and illustrate teaching points with clinical cases.

Inflammatory mimickers of pancreatic adenocarcinoma.

Pancreatic ductal adenocarcinoma can be a difficult imaging diagnosis early in its course given its subtle imaging findings such as focal pancreatic duct dilatation, abrupt duct cut-off, and encasement of vasculature. A variety of pancreatitidies have imaging findings that mimic pancreatic ductal adenocarcinoma and lead to mass formation making diagnosis even more difficult on imaging alone. These conditions include acute focal pancreatitis, chronic pancreatitis, autoimmune pancreatitis, and paraduodenal ("groove") pancreatitis. This review will focus on imaging findings that can help differentiate these inflammatory processes from pancreatic ductal adenocarcinoma.

Ultrasound Assessment of Acute Kidney Injury.

Ultrasound assessment of the kidneys in patients with renal impairment has been described in various ways in the critical care, nephrology, and radiology literature, resulting in a somewhat heterogeneous picture of the gray-scale and Doppler ultrasound manifestation of acute kidney injury (AKI). Given that ultrasound assessment can potentially identify reversible causes of AKI or identify underlying chronic kidney disease, it is important for radiologists to be aware of the common etiologies of AKI and the spectrum of ultrasound findings. We review the definition and etiologies of renal injury and introduce the ultrasound SERVeillance framework-assessment of renal size, echogenicity, renal hilum, and vascularity-for the imaging assessment of AKI.

The Radiologist's Gaze: Mapping Three-Dimensional Visual Search in Computed Tomography of the Abdomen and Pelvis.

A radiologist's search pattern can directly influence patient management. A missed finding is a missed opportunity for intervention. Multiple studies have attempted to describe and quantify search patterns but have mainly focused on chest radiographs and chest CTs. Here, we describe and quantify the visual search patterns of 17 radiologists as they scroll through 6 CTs of the abdomen and pelvis. Search pattern tracings varied among individuals and remained relatively consistent per individual between cases. Attendings and trainees had similar eye metric statistics with respect to time to first fixation (TTFF), number of fixations in the region of interest (ROI), fixation duration in ROI, mean saccadic amplitude, or total number of fixations. Attendings had fewer numbers of fixations per second versus trainees (p < 0.001), suggesting efficiency due to expertise. In those cases that were accurately interpreted, TTFF was shorter (p = 0.04), the number of fixations per second and number of fixations in ROI were higher (p = 0.04, p = 0.02, respectively), and fixation duration in ROI was increased (p = 0.02). We subsequently categorized radiologists as "scanners" or "drillers" by both qualitative and quantitative methods and found no differences in accuracy with most radiologists being categorized as "drillers." This study describes visual search patterns of radiologists in interpretation of CTs of the abdomen and pelvis to better approach future endeavors in determining the effects of manipulations such as fatigue, interruptions, and computer-aided detection.

The Impact of Interruptions on Chest Radiograph Interpretation: Effects on Reading Time and Accuracy.

RATIONALE AND OBJECTIVES: The objective of this study was to experimentally test the effect of interruptions on image interpretation by comparing reading time and response accuracy of interrupted case reads to uninterrupted case reads in resident and attending radiologists. MATERIALS AND METHODS: Institutional review board approval was obtained before participant recruitment from an urban academic health-care system during January 2016-March 2016. Eleven resident and 12 attending radiologists examined 30 chest radiographs, rating their confidence regarding the presence or the absence of a pneumothorax. Ten cases were normal (ie, no pneumothorax present), 10 cases had an unsubtle pneumothorax (ie, readily perceivable by a nonexpert), and 10 cases had a subtle pneumothorax. During three reads of each case type, the participants were interrupted with 30 seconds of a secondary task. The total reading time and the accuracy of interrupted and uninterrupted cases were compared. A mixed-factors analysis of variance was run on reading time and accuracy with experience (resident vs attending) as a between-subjects factor and case type (normal, unsubtle, or subtle) and interruption (interruption vs no interruption) as within-subjects factors. RESULTS: Interrupted tasks had significantly longer reading times than uninterrupted cases (P = .032). During subtle cases, interruptions reduced accuracy (P = .034), but during normal cases, interruptions increased accuracy (P = .038). CONCLUSIONS: Interruptions increased reading times and increased the tendency for a radiologist to conclude that a case is normal for both resident and attending radiologists, demonstrating that interruptions reduce efficiency and introduce patient safety concerns during reads of abnormal cases.

PathBot: A Radiology-Pathology Correlation Dashboard.

Pathology is considered the "gold standard" of diagnostic medicine. The importance of radiology-pathology correlation is seen in interdepartmental patient conferences such as "tumor boards" and by the tradition of radiology resident immersion in a radiologic-pathology course at the American Institute of Radiologic Pathology. In practice, consistent pathology follow-up can be difficult due to time constraints and cumbersome electronic medical records. We present a radiology-pathology correlation dashboard that presents radiologists with pathology reports matched to their dictations, for both diagnostic imaging and image-guided procedures. In creating our dashboard, we utilized the RadLex ontology and National Center for Biomedical Ontology (NCBO) Annotator to identify anatomic concepts in pathology reports that could subsequently be mapped to relevant radiology reports, providing an automated method to match related radiology and pathology reports. Radiology-pathology matches are presented to the radiologist on a web-based dashboard. We found that our algorithm was highly specific in detecting matches. Our sensitivity was slightly lower than expected and could be attributed to missing anatomy concepts in the RadLex ontology, as well as limitations in our parent term hierarchical mapping and synonym recognition algorithms. By automating radiology-pathology correlation and presenting matches in a user-friendly dashboard format, we hope to encourage pathology follow-up in clinical radiology practice for purposes of self-education and to augment peer review. We also hope to provide a tool to facilitate the production of quality teaching files, lectures, and publications. Diagnostic images have a richer educational value when they are backed up by the gold standard of pathology.

Multifocal hemangioendothelioma of the lumbar spine and response to surgical resection and radiation.

BACKGROUND CONTEXT: Epithelioid hemangioendothelioma rarely occurs in the lumbosacral spine, with very few case reports of spinal hemangioendothelioma in the literature. There is variability in aggressiveness of these lesions without established treatment guidelines. PURPOSE: The aim was to present a case of epithelioid hemangioendothelioma in the lumbar spine, including magnetic resonance imaging (MRI) findings, which rapidly progressed over a 2-month period as regional multifocal lumbosacral spinal lesions with epidural extension causing severe spinal canal stenosis. STUDY DESIGN/SETTING: This was a case report in a university hospital setting. PATIENT SAMPLE: The sample included an otherwise healthy adult male with low back pain. METHODS: Multimodality imaging was performed to help with diagnosis and management including computed tomography, MRI, and positron emission tomography (PET). The patient was treated by embolization, L5 corpectomy and L4-S1 stabilization, and radiation therapy. The diagnosis was confirmed by tissue biopsy. RESULTS: The patient initially presented with severe back and leg pain after a vertebroplasty for an L5 compression fracture at an outside hospital where biopsy was negative for malignancy. Magnetic resonance imaging showed diffuse abnormality of L5 with several smaller lesions in the sacrum. Due to progressive pain 2 weeks after the vertebroplasty, the patient underwent an L5 laminectomy, L4-S1 instrumented posterior fusion, and attempted partial corpectomy for stenosis. At this surgery, the L5 corpectomy was aborted owing to profound bleeding. Pathology was again negative for malignancy. Presumed to be an atypical hemangioma, the lesion was embolized before repeat surgery where the thecal sac was decompressed by partial L5 corpectomy. Biopsy at this time revealed a vascular neoplasm, with hemangioendothelioma not excluded. Approximately 2 months after the stabilization procedure, the patient had increasing pain and bilateral lower extremity weakness. Magnetic resonance imaging was performed and demonstrated marked local progression of disease with new multifocal lesions involving L4 through S2 vertebrae and new severe spinal canal stenosis. These lesions were subsequently treated with localized radiation therapy. Magnetic resonance imaging 2 months after radiation therapy showed significant regression of the epidural tumor although a new metastatic lesion was discovered at T6 vertebra. CONCLUSIONS: Spinal hemangioendothelioma is a rare disease and can present in variable forms, including as a multifocal regional process--which may be mistaken for infection. Additionally, there are no standard treatment protocols for this entity. We present the extensive imaging and treatment of a single case of rapidly progressive lumbar epithelioid hemangioendothelioma, which to our knowledge has not been described with this multifocal appearance in the lumbar spine.