Renal lesion characterization: clinical utility of single-phase dual-energy CT compared to MRI and dual-phase single-energy CT.

OBJECTIVES: To assess the impact of dual-energy CT (DECT) utilization in practice by measuring the readers' confidence, the need for additional image requests, and diagnostic performance in renal lesion assessment, compared to single-energy CT (SECT) using contrast-enhanced MRI to establish the reference standard. MATERIALS AND METHODS: Sixty-nine patients (M/F = 47/22) who underwent a dual-phase renal SECT (n = 34) or DECT (n = 35) and had a contrast-enhanced MRI within 180 days were retrospectively collected. Three radiologists assessed images on different sessions (SECT, DECT, and MRI) for (1) likely diagnosis (enhancing/non-enhancing); (2) diagnostic confidence (5-point Likert scale); (3) need for additional imaging test (yes/no); and (4) need for follow-up imaging (yes/no). Diagnostic accuracy was compared using AUC; p value < 0.05 was considered significant. RESULTS: One hundred fifty-six lesions consisting of 18% enhancing (n = 28/156, mean size: 30.37 mm, range: 9.9-94 mm) and 82% non-enhancing (n = 128/156, mean size: 23.91 mm, range: 5.0-94.2 mm) were included. The confidence level was significantly lower for SECT than their MRI (4.50 vs. 4.80, p value < 0.05) but not significantly different for DECT and the corresponding MRI (4.78 vs. 4.78, p > 0.05). There were significantly more requests for additional imaging in the SECT session than the corresponding MRI (20% vs. 4%), which was not significantly different between DECT and their MRI counterpart session (5.7% vs. 4.9%). Inter-reader agreement was almost perfect for DECT and MRI (kappa: 0.8-1) and substantial in SECT sessions (kappa: 0.6-0.8) with comparable diagnostic accuracy between SECT, DECT, and MRI (p value > 0.05). CONCLUSION: Single-phase DECT allows confident and reproducible characterization of renal masses with fewer recommendation for additional and follow-up imaging tests than dual-phase SECT and a performance similar to MRI. KEY POINTS: • DECT utilization leads to similar additional image requests to MRI (5.7% vs. 4.9%, p value > 0.05), whereas single-energy CT utilization leads to significantly higher image requests (20% vs. 4%, p value < 0.05). • DECT and MRI utilization bring highly reproducible results with almost perfect inter-reader agreement (kappa: 0.8-1), better than the inter-reader agreement in SECT utilization (kappa: 0.6-0.8). • Readers' confidence was not significantly altered between DECT and their MRI readout session (p value > 0.05). In contrast, confidence in the diagnosis was significantly lower in the SECT session than their MRI readout (p value < 0.05).

Comparison of Four Dual-Energy CT Scanner Technologies for Determining Renal Stone Composition: A Phantom Approach.

Background Studies have investigated the value of various dual-energy CT (DECT) technologies for determining renal stone composition. However, sparse multivendor comparison data exist. Purpose To compare the performance of four DECT technologies in determining renal stone composition at standard- and low-dose acquisitions. Materials and Methods This was an in vitro phantom study. Seventy-one urinary stones (size: 2.7-14.1 mm) of known chemical composition (51 calcium, four struvite, four cystine, and 12 urate) were placed in a custom-made cylindrical phantom. Consecutive scans with manufacturer-recommended protocols and dose-optimized institutional protocols (up to 80% reduction in volumetric CT dose index) were obtained with rapid kilovolt peak switching DECT (rsDECT) (n = 2), dual-source DECT (n = 2), twin-beam DECT (tbDECT) (n = 1), and dual-layer detector-based CT (dlDECT) (n = 1) scanners. The image data sets were analyzed using effective atomic number and dual-energy ratio indexes of maximally available and comparable spectra. The performance of each combination of scanner technology, method, and acquisition was assessed. Logistic regression models were used to calculate the area under the receiver operating characteristic curve (AUC). Results After image analysis, all scanners except tbDECT had an AUC greater than 0.95 in at least one acquisition in distinguishing urate from other stones. All DECT techniques were able to help differentiate calcium oxalate monohydrate stones with moderate accuracy (AUC: 0.70-0.83), and brushite was differentiated from urate with AUC greater than 0.99. There was no correlation between performance and acquisition with dose-optimized and/or vendor-recommended settings. Conclusion All four dual-energy CT (DECT) technologies enabled accurate determination of stone composition at standard- and low-dose acquisitions; however, performance varied based on the scanner parameters, DECT technique, and stone type. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Ringl and Apfaltrer in this issue.

Nonaccidental Injury in the Elderly: What Radiologists Need to Know.

Elder abuse may result in serious physical injuries and long-term psychological consequences and can be life threatening. Over the past decade, attention to elder abuse has increased owing to its high prevalence, with one in six people aged 60 years and older experiencing some form of abuse worldwide. Despite this, the detection and reporting rates remain relatively low. While diagnostic imaging is considered critical in detection of child abuse, it is relatively underused in elder abuse. The authors discuss barriers to use of imaging for investigation and diagnosis of elder abuse, including lack of training, comorbidities present in this vulnerable population, and lack of communication among the intra- and interdisciplinary care providers. Moreover, imaging features that should raise clinical concern for elder abuse are reviewed, including certain types of fractures (eg, posterior rib), characteristic soft-tissue and organ injuries (eg, shoulder dislocation), and cases in which the reported mechanism of injury is inconsistent with the imaging findings. As most findings suggesting elder abuse are initially discovered at radiography and CT, the authors focus mainly on use of those modalities. This review also compares and contrasts elder abuse with child abuse. Empowered with knowledge of elderly victims' risk factors, classic perpetrator characteristics, and correlative imaging findings, radiologists should be able to identify potential abuse in elderly patients presenting for medical attention. Future recommendations for research studies and clinical workflow to increase radiologists' awareness of and participation in elder abuse detection are also presented. An invited commentary by Jubanyik and Gettel is available online. Online supplemental material is available for this article. ©RSNA, 2022.

"All-in-one" window/level whole-body computed tomography scan - A faster way to evaluate trauma cases.

PURPOSE: To investigate the accuracy and total assessment time (TAT) of the "All-in-one" (AIO)-window/level setting for whole-body computed tomography (CT) image compared to multiple tissue-specific window/level settings conventionally used for detection of traumatic injuries. METHOD: Contrast-enhanced chest, abdomen, and pelvic CT scans of 50 patients who presented to our emergency department (ED) for major trauma were retrospectively selected. In a simulation of a "wet read" performed at the CT scanner console, 6 readers with different levels of experience had up to 3 min to describe any traumatic finding identified on the CTs. The readers reviewed each patient in two different sessions separated by a washout period to suppress any recall bias from one session to the next. Each scan was reviewed once using the AIO-window/level setting and another time using the conventional bone, lung, and soft tissue window/level display settings, in a randomized order. The CT reports were used as reference standard. RESULTS: Overall, there was no statistically significant difference in the assessment accuracy of the review based on the AIO or the conventional window/level settings (0.89 ± 0.09 vs 0.90 ± 0.08). Using the AIO-window/level settings, TAT was 14.3 s faster when compared with the conventional window/level settings (2.33 ± 0.63 vs 2.57 ± 0.51 min; p < 0.001). CONCLUSIONS: In a time-delimited image review, similar diagnostic accuracy was reached faster using the AIO vs the conventional window/level settings. When providing a "wet read" at the CT console, the ability to identify traumatic injury using a single AIO-window/level may help expedite patient management.

Correction to: Diagnostic performance of dual-energy CT and subtraction CT for renal lesion detection and characterization.

The original version of this article, published on 27 May 2019, unfortunately contained a mistake. The following correction has therefore been made in the original.

Diagnostic performance of dual-energy CT and subtraction CT for renal lesion detection and characterization.

PURPOSE: To compare the effect of dual-energy CT (DECT) material density datasets on diagnostic performance, readers' confidence, and interpretation time for renal lesion detection and characterization in comparison to subtraction CT (SCT). MATERIAL AND METHODS: One hundred fourteen patients (69/45 = M/F, mean age = 67 years) who underwent contrast-enhanced DECT between January 2015 and February 2018 for suspected renal mass were included retrospectively. For each patient, three radiologists assessed three image datasets: group A, material density iodine (MDI) + material density water (MDW); group B, SCT only; and group C, SCT + true unenhanced phase + virtual monochromatic images at 65 keV. Readers evaluated image quality (4-point scale), the number of lesions, and likely diagnosis. Reading times were recorded. Quantitatively, iodine concentration (IC from MDI) and delta Hounsfield units (ΔHU) for all lesions were measured. Diagnostic accuracy was compared using the area under the receiver operating characteristic curve (AUC). Image quality and interpretation time were compared with Kruskal-Wallis and t tests. RESULTS: Study cohort (230 lesions; mean size = 23.63 mm (5-116 mm)) consisted of 60 enhancing, 158 non-enhancing, and 12 lipid-dominant angiomyolipoma lesions. Significantly higher image quality was demonstrated for MDI compared to SCT (mean score = 3.82 vs. 3; p < 0.05). Comparable diagnostic accuracy was observed for group A (AUC = 0.88) and group C (AUC = 0.87) and was higher compared to that for group B (AUC = 0.75). Group A was read faster than group C (41.49 s vs. 71.45 s per exam; p < 0.05). Both IC and ΔHU values had high accuracy (AUC = 0.97) for differentiating enhancing vs. non-enhancing lesions; however, IC enabled differentiation of clear cell renal cell carcinoma from other enhancing lesions with moderate accuracy (AUC = 0.73). CONCLUSION: MDI images increase readers' confidence for renal lesion detection and characterization while providing a more efficient radiologist workflow, irrespective of readers' experience. KEY POINTS: • Material density iodine (MDI) images enable faster interpretation due to high image quality and potentially reduced need for quantitation. • MDI images increase diagnostic confidence of readers, irrespective of radiologists' experience. • High accuracy with dual-energy CT (DECT) can potentially reduce healthcare costs by eliminating the need for additional investigations.

Differentiating primary from metastatic ovarian tumors of gastrointestinal origin by CT.

PURPOSE: To determine differentiating CT imaging features of primary ovarian cancers from ovarian metastases of gastrointestinal origin. METHODS: Retrospective study of 50 patients with new ovarian lesions on CT, half were primary ovarian cancers and half gastrointestinal metastases. Two blinded independent readers described tumor characteristics on CT (size, laterality, margin, etc.) and ancillary features (ascites, peritoneal seeding, lymphadenopathy, etc.). Patient age, sex, cancer history, and tumor marker levels for CA-125 and CEA were collected. Wilcoxon test and Pearson's chi-squared test were used for statistical analysis. RESULTS: 50 patients with mean age of 62.1 years were included. Ovarian metastases were more likely to be cystic/mainly cystic (p=0.013), have smooth margins (p=0.011), and have no/mild enhancement (p<0.001). Primary ovarian lesions were associated with moderate to large volume of ascites (p=0.047) and more commonly seen with lymphadenopathy (p=0.008). Laterality was not significantly different between the two groups. CA-125 level was more commonly elevated in primary ovarian lesions (87% vs 50%, p=0.018), and with much higher values (1076.5 vs 155.1, p=0.013). CEA level was more commonly elevated in metastatic ovarian lesions (83.3% vs 15.4%, p<0.001), and with higher values (72.4 vs 2.1, p<0.001). CONCLUSION: Ovarian metastases were more frequently smooth-margined and cystic with little enhancement. Primary ovarian lesions were more commonly associated with lymphadenopathy and larger volume of ascites. Tumor markers CEA and CA-125 were more frequently elevated in metastatic and primary lesions, respectively. Cancer history was the only variable that increased the odds of metastasis and therefore it is important to always correlate with history of cancer.

Ondansetron in patients with tinnitus: randomized double-blind placebo-controlled study.

The aim of this study was to assess the effect of ondansetron on symptoms of patients with subjective tinnitus accompanied by sensorineural hearing loss or normal hearing. Sixty patients with a chief complaint of tinnitus (with duration of more than 3 months) were equally randomized to ondansetron or placebo for 4 weeks. The dose of ondansetron was gradually increased from 4 mg/day (one tablet) to 16 mg/day (4 tablets) during 12 days and then continued up to 4 weeks. The exact number of tablets was prescribed in the placebo group. Patients underwent audiologic examinations and filled questionnaires at baseline and after 4 weeks of treatment. Our primary outcomes were changes in Tinnitus Handicap Inventory questionnaire (THI), Tinnitus Severity Index (TSI) and visual analog scale (VAS) scores. Our secondary outcomes were the changes in depression and anxiety based on Hospital Anxiety and Depression (HADS) questionnaire, side effects, tinnitus loudness matching, tinnitus pitch matching, pure tone audiometry and speech recognition threshold (SRT). In the ondansetron and placebo groups, 27 and 26 patients completed the study, respectively. The changes in VAS (P = 0.934), THI (P = 0.776), anxiety (P = 0.313) and depression (P = 0.163) scores were not different between the groups. TSI score decreased significantly in the ondansetron compared with the placebo group (P = 0.004). Changes in tinnitus loudness matching (P = 0.75) and pitch matching (P = 0.56) did not differ between the two groups. Ondansetron, but not placebo, decreased the SRT threshold (right, P < 0.001; left, P = 0.043) and mean PTA (right, P = 0.006; left, P < 0.001). In conclusion, ondansetron reduces the severity of tinnitus hypothetically through cochlear amplification.

Head CT deep learning model is highly accurate for early infarct estimation.

Non-contrast head CT (NCCT) is extremely insensitive for early (< 3-6 h) acute infarct identification. We developed a deep learning model that detects and delineates suspected early acute infarcts on NCCT, using diffusion MRI as ground truth (3566 NCCT/MRI training patient pairs). The model substantially outperformed 3 expert neuroradiologists on a test set of 150 CT scans of patients who were potential candidates for thrombectomy (60 stroke-negative, 90 stroke-positive middle cerebral artery territory only infarcts), with sensitivity 96% (specificity 72%) for the model versus 61-66% (specificity 90-92%) for the experts; model infarct volume estimates also strongly correlated with those of diffusion MRI (r2 > 0.98). When this 150 CT test set was expanded to include a total of 364 CT scans with a more heterogeneous distribution of infarct locations (94 stroke-negative, 270 stroke-positive mixed territory infarcts), model sensitivity was 97%, specificity 99%, for detection of infarcts larger than the 70 mL volume threshold used for patient selection in several major randomized controlled trials of thrombectomy treatment.

Immunotherapy-related renal toxicity causes reversible renal enlargement.

PURPOSE: Prior case reports have noted an increase in renal size and perinephric stranding accompanying immunotherapy-related renal toxicity due to checkpoint-inhibitor therapy. The purpose of this investigation was to systematically evaluate if immunotherapy-related renal toxicity affects renal size and possible associated imaging findings. METHODS: This retrospective multi-hospital study included 25 patients (13 men), mean age 67 years (range 46-83) who received immune-checkpoint inhibitors for cancer treatment, developed biopsy-proven immunotherapy-related nephritis, and who also had abdominal imaging before, during, and after nephritis was diagnosed. Long axis renal diameter, renal corticomedullary differentiation/enhancement and perinephric stranding were evaluated by two readers at three timepoints: (1) prior to checkpoint inhibitor therapy (baseline), (2) after biopsy-proven immunotherapy-related nephritis (post-treatment), and (3) following renal function recovery (follow-up). Intraclass correlation coefficient and Cohen's Kappa were calculated to quantify agreement. Logistic regression analysis was implemented to measure the association between each timepoint and imaging features. RESULTS: Reader agreement on kidney measurements was excellent (ICC = 0.87). There was an increase in renal size between baseline and post-treatment (p = 0.001), followed by a decrease between post-treatment to follow-up (p < 0.001). Agreement was perfect for abnormal renal corticomedullary differentiation/enhancement (Kappa = 1, p < 0.001) and almost perfect for perinephric stranding (Kappa = 0.97, p < 0.001). Neither post-treatment nor follow-up imaging findings were significantly associated with these findings compared to the baseline (p = 0.2-0.6). CONCLUSION: Immunotherapy-related renal toxicity was associated with an increase in renal size coincident with acute renal dysfunction.

Imaging Information Overload: Quantifying the Burden of Interpretive and Non-Interpretive Tasks for Computed Tomography Angiography for Aortic Pathologies in Emergency Radiology.

RATIONALE: Over the past decade, technological advances have provided new tools for radiologists. However, the effect of these technological advances on radiologist workload and detecting pathologies needs to be assessed. OBJECTIVE: The purpose of this study is to assess the workload, including non-interpretative tasks, associated with Computed Tomography Angiogram (CTA) of Aorta exams performed in the Emergency Department (ED) over a 10-year period and their relationship to detection of aortic pathology. MATERIALS AND METHODS: This is a retrospective analysis of CTAs of Aorta performed on adults with suspected acute aortic pathology within the ED at an academic level I quaternary care hospital from January 1, 2005, through December 31, 2015. Data assessed included (1) Interpretive tasks: total number of images, number of reformat series, number of radiology reports with positive aortic pathologies; and (2) Non-interpretative tasks: recommendations and documentation of verbal communication with requesting providers. Statistical analyses were performed to assess temporal trends of variables. P values less than 0.05 are considered significant. RESULTS: A total of 4368 examinations (mean age: 69.8, M/F: 56.8%/43.2%) were performed. Studies per year increased significantly from 2005 (n = 278) to 2007 (n = 445), but not significantly after. The number of images and reformat series per scan increased from 487 to 2819 and 6.4 to 13.7, respectively (both P-value < 0.01). The proportion of exams with aortic findings did not significantly change (28.1% in 2005 and 24.9% in 2015). However, The proportions of exams with verbal communication increased from 9.3% to 24.6% and with recommendations from 1.8% to 28.9% (both P-value < 0.01). CONCLUSION: During a 10-year period, CTAs performed in the ED for suspected aortic pathology were associated with a significant increase in images created, reformat series generated, recommendations, and verbal communications with ordering providers without a concomitant increase in the rate of aortic pathologies. To completely capture the complexities of CTA workloads, non-interpretive tasks such as radiologist recommendations and verbal communications should also be included.

Using CT Encounters to Improve Colorectal Cancer Screening Utilization: Cross-Sectional Survey Results From the National Health Interview Survey.

PURPOSE: Millions of patients undergo CT imaging examinations every year. These encounters may represent opportunities to improve colorectal cancer (CRC) screening rates among patients who have not received recommended CRC screening. Using a nationally representative cross-sectional survey, our purpose was to estimate the proportion of patients who have undergone CT examinations who have not received recommended CRC screening. METHODS: Survey respondents aged 45-75 years in the 2015 National Health Interview Survey without history of CRC were included. Proportion of patients who have undergone CT examinations among those who have not received recommended CRC screening was estimated. Multiple variable logistic regression analyses were performed to evaluate the association between sociodemographic characteristics and CRC screening adherence. Analyses were conducted accounting for complex survey design features. RESULTS: Sixteen thousand two hundred and six survey respondents met inclusion criteria. About 44.3% (43.1, 45.5) reported having ever received a CT scan and 50.8% (49.6, 51.9) underwent CRC screening. Among those who previously had CT scans, Asian race participants and participants without health insurance coverage had lower odds of adherence, while increasing household income and education were associated with higher odds of adherence (P < 0.01). Among participants who did not receive CRC screening, 33.7% (32.1%, 35.3%) reported having a CT scan, representing an estimated 15,278,667 people across the United States. CONCLUSION: Among patients who have not received recommended CRC screening, nearly 1 out of 3 report having undergone a CT examination. CT encounters may represent opportunities to improve overall CRC screening rates.

RadTranslate: An Artificial Intelligence-Powered Intervention for Urgent Imaging to Enhance Care Equity for Patients With Limited English Proficiency During the COVID-19 Pandemic.

PURPOSE: Disproportionally high rates of coronavirus disease 2019 (COVID-19) have been noted among communities with limited English proficiency, resulting in an unmet need for improved multilingual care and interpreter services. To enhance multilingual care, the authors created a freely available web application, RadTranslate, that provides multilingual radiology examination instructions. The purpose of this study was to evaluate the implementation of this intervention in radiology. METHODS: The device-agnostic web application leverages artificial intelligence text-to-speech technology to provide standardized, human-like spoken examination instructions in the patient's preferred language. Standardized phrases were collected from a consensus group consisting of technologists, radiologists, and ancillary staff members. RadTranslate was piloted in Spanish for chest radiography performed at a COVID-19 triage outpatient center that served a predominantly Spanish-speaking Latino community. Implementation included a tablet displaying the application in the chest radiography room. Imaging appointment duration was measured and compared between pre- and postimplementation groups. RESULTS: In the 63-day test period after launch, there were 1,267 application uses, with technologists voluntarily switching exclusively to RadTranslate for Spanish-speaking patients. The most used phrases were a general explanation of the examination (30% of total), followed by instructions to disrobe and remove any jewelry (12%). There was no significant difference in imaging appointment duration (11 ± 7 and 12 ± 3 min for standard of care versus RadTranslate, respectively), but variability was significantly lower when RadTranslate was used (P = .003). CONCLUSIONS: Artificial intelligence-aided multilingual audio instructions were successfully integrated into imaging workflows, reducing strain on medical interpreters and variance in throughput and resulting in more reliable average examination length.

Development, validation, and pilot MRI safety study of a high-resolution, open source, whole body pediatric numerical simulation model.

Numerical body models of children are used for designing medical devices, including but not limited to optical imaging, ultrasound, CT, EEG/MEG, and MRI. These models are used in many clinical and neuroscience research applications, such as radiation safety dosimetric studies and source localization. Although several such adult models have been reported, there are few reports of full-body pediatric models, and those described have several limitations. Some, for example, are either morphed from older children or do not have detailed segmentations. Here, we introduce a 29-month-old male whole-body native numerical model, "MARTIN", that includes 28 head and 86 body tissue compartments, segmented directly from the high spatial resolution MRI and CT images. An advanced auto-segmentation tool was used for the deep-brain structures, whereas 3D Slicer was used to segment the non-brain structures and to refine the segmentation for all of the tissue compartments. Our MARTIN model was developed and validated using three separate approaches, through an iterative process, as follows. First, the calculated volumes, weights, and dimensions of selected structures were adjusted and confirmed to be within 6% of the literature values for the 2-3-year-old age-range. Second, all structural segmentations were adjusted and confirmed by two experienced, sub-specialty certified neuro-radiologists, also through an interactive process. Third, an additional validation was performed with a Bloch simulator to create synthetic MR image from our MARTIN model and compare the image contrast of the resulting synthetic image with that of the original MRI data; this resulted in a "structural resemblance" index of 0.97. Finally, we used our model to perform pilot MRI safety simulations of an Active Implantable Medical Device (AIMD) using a commercially available software platform (Sim4Life), incorporating the latest International Standards Organization guidelines. This model will be made available on the Athinoula A. Martinos Center for Biomedical Imaging website.

Analysis of the Effects of a Patient-Centered Rideshare Program on Missed Appointments and Timeliness for MRI Appointments at an Academic Medical Center.

PURPOSE: The aim of this study was to assess the differences in timeliness to MRI appointments and missed MRI appointment rates before and after the implementation of a rideshare program. METHODS: Retrospective analysis of a rideshare program was performed 9 months after implementation to compare the effects before and after implementation. Variables obtained included demographics, MRI appointment variables, and data related to rideshare use. Descriptive statistics and linear and logistic regression analyses were used to compare demographic characteristics among patients using the rideshare program with (1) those who did not use the rideshare program after implementation and (2) patients before rideshare implementation. Rates of missed appointments derived from patient-related, same-day appointment cancellations were analyzed using logistic regression analyses. Timeliness was analyzed using linear regression analyses. All analyses were adjusted for potential confounders. RESULTS: Of 7,707 patients scheduled for MRI appointments during the postintervention period, 151 patients used the rideshare service (1.95%). There were no statistically significant differences in missed appointment rates after rideshare implementation (adjusted odds ratio, 1.09; 95% confidence interval, 0.93-1.27; P = .275). Patients using the rideshare service were more likely to be on time (adjusted coefficient = 13.0; 95% confidence interval, 5.4-20.5; P = .001). Older patients (P = .001), unemployed patients (P < .001), and patients without commercial insurance (P < .001) were more likely to use the rideshare service. CONCLUSIONS: Implementation of a rideshare program did not significantly decrease missed appointment rates, but it significantly improved timeliness to MRI appointments while assisting at-risk patient populations reporting transportation barriers.

Endoscopic and surgical treatment options for chronic pancreatitis: an imaging perspective.

Chronic pancreatitis is a chronic fibro-inflammatory syndrome characterized by chronic pancreatic inflammation leading to fibrosis and scarring. Patients with this multifactorial debilitating illness often require endoscopic or surgical intervention for treatment. Radiologists play a crucial role in pre-therapeutic workup as well as post-treatment imaging of chronic pancreatitis. This review summarizes the most common surgical and endoscopic treatment options that are currently available for chronic pancreatitis, including the implications on imaging.

Abdominal CT manifestations of adverse events to immunotherapy: a primer for radiologists.

Immunotherapy is a rapidly growing field within oncology and is being increasingly used in the management of several malignancies. Due to their unique mechanism of action on the immune system and neoplastic cells, the response pattern and adverse events of this novel therapy are distinct from conventional systemic therapies. Accordingly, the imaging appearances following immunotherapy including adverse events are unique and at times perplexing. Imaging is integral to management of patients on immunotherapeutic agents and a thorough understanding of its mechanism, response patterns and adverse events is crucial for precise interpretation of imaging studies. This review provides a description of the mechanism of action of current immunotherapeutic agents and the organ-wise description of their side effects.

Radiomics Texture Features in Advanced Colorectal Cancer: Correlation with BRAF Mutation and 5-year Overall Survival.

Purpose: To explore the potential of radiomics texture features as potential biomarkers to enable detection of the presence of BRAF mutation and prediction of 5-year overall survival (OS) in stage IV colorectal cancer (CRC). Materials and Methods: In this retrospective study, a total of 145 patients (mean age, 61 years ± 14 [standard deviation {SD}]; 68 female patients and 77 male patients) with stage IV CRC who underwent molecular profiling and pretreatment contrast material-enhanced CT scans between 2004 and 2018 were included. Tumor radiomics texture features, including the mean, the SD, the mean value of positive pixels (MPP), skewness, kurtosis, and entropy, were extracted from regions of interest on CT images after applying three Laplacian-of-Gaussian filters known as spatial scaling factors (SSFs) (SSF = 2, fine; SSF = 4, medium; SSF = 6, coarse) by using specialized software; values of these parameters were also obtained without filtration (SSF = 0). The Wilcoxon rank sum test was used to assess differences between mutated versus wild-type BRAF tumors. Associations between radiomics texture features and 5-year OS were determined by using Kaplan-Meier estimators using the log-rank test and multivariate Cox proportional-hazards regression analysis. Results: The SDs and MPPs of radiomic texture features were significantly lower in BRAF mutant tumors than in wild-type BRAF tumors at SSFs of 0, 4, and 6 (P = .006, P = .007, and P = .005, respectively). Patients with skewness less than or equal to -0.75 at an SSF of 0 and a mean of greater than or equal to 17.76 at an SSF of 2 showed better 5-year OS (hazard ratio [HR], 0.53 [95% confidence interval {CI}: 0.29, 0.94]; HR, 0.40 [95% CI: 0.22, 0.71]; log-rank P = .025 and P = .002, respectively). Tumor location (right colon vs left colon vs rectum) had no significant impact on the clinical outcome (log-rank P = .53). Conclusion: Radiomics texture features can serve as potential biomarkers for determining BRAF mutation status and as predictors of 5-year OS in patients with advanced-stage CRC.Keywords: Abdomen/GI, CT, Comparative Studies, Large BowelSupplemental material is available for this article.© RSNA, 2020.

Imaging predictors of BRAF mutation in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the leading causes of cancer deaths and is associated with various genetic mutations. BRAF mutations, found in approximately 10% of all CRCs, are associated with negative predictive outcomes. The goal of this study was to assess the relationship between the imaging findings and BRAF statuses of CRC patients. MATERIALS AND METHODS: The study population was colorectal cancer patients who underwent biopsy or surgery in a single institution from September 2004 to October 2018, and in whom the pathologic specimens were tested for BRAF mutation. The exclusion criteria were (1) patients without pre-operative cross-sectional imaging, and (2) patients whose tumors were invisible on imaging. Two hundred and eighty-three patients met the inclusion criteria. Among them, 128 were excluded, and a total of 155 patients were enrolled in the study. RESULTS: BRAF mutations were significantly more common in female patients (p = 0.007). Patients with mutated BRAF were significantly older than those with wild-type BRAF (p = 0.001). BRAF-mutant tumors were predominant in right-sided colon (p = 0.001) with higher numbers of polypoid- or mass-like morphology (p = 0.019) and heterogeneous enhancement (p = 0.009). Compared to their wild-type counterparts, BRAF-mutated CRCs have a lower occurrence of non-peritoneal, and overall metastases (p = 0.013 and p = 0.004, respectively). Logistic regression analysis showed three significant factors for the prediction of BRAF mutations in CRC patients: right-sided location (p = 0.002), heterogeneous tumor enhancement (p = 0.039), and lack of non-peritoneal metastasis (p = 0.043). CONCLUSION: By recognizing the specific imaging features of BRAF-mutant CRCs, it would be possible to identify a patient who has a higher risk of carrying BRAF mutation.