Evaluation of abdominal computed tomography findings in patients with COVID-19: a multicenter study

PURPOSE: To evaluate the frequency of abdominal computed tomography (CT) findings in patients with coronavirus disease-2019 (COVID-19) and interrogate the relationship between abdominal CT findings and patient demographic features, clinical findings, and laboratory test results as well as the CT atherosclerosis score in the abdominal aorta. METHODS: This study was designed as a multicenter retrospective study. The abdominal CT findings of 1.181 patients with positive abdominal symptoms from 26 tertiary medical centers with a positive polymerase chain-reaction test for severe acute respiratory syndrome coronavirus 2 were reviewed. The frequency of ischemic and non-ischemic CT findings as well as the association between CT findings, clinical features, and abdominal aortic calcific atherosclerosis score (AA-CAS) were recorded. RESULTS: Ischemic and non-ischemic abdominal CT findings were detected in 240 (20.3%) and 328 (27.7%) patients, respectively. In 147 patients (12.4%), intra-abdominal malignancy was present. The most frequent ischemic abdominal CT findings were bowel wall thickening (n = 120; 10.2%) and perivascular infiltration (n = 40; 3.4%). As for non-ischemic findings, colitis (n = 91; 7.7%) and small bowel inflammation (n = 73; 6.2%) constituted the most frequent disease processes. The duration of hospital stay was found to be higher in patients with abdominal CT findings than in patients without any positive findings (13.8 ± 13 vs. 10.4 ± 12.8 days, P < 0.001). The frequency of abdominal CT findings was significantly higher in patients who did not survive the infection than in patients who were discharged after recovery (41.7% vs. 27.4%, P < 0.001). Increased AA-CAS was found to be associated with a higher risk of ischemic conditions in abdominal CT examinations. CONCLUSION: Abdominal symptoms in patients with COVID-19 are usually associated with positive CT findings. The presence of ischemic findings on CT correlates with poor COVID-19 outcomes. A high AA-CAS is associated with abdominal ischemic findings in patients with COVID-19.

Past, Present, and Future of Serum Tumor Markers in Management of Ovarian Cancer: A Guide for the Radiologist.

The ability to accurately detect early ovarian cancer and subsequently monitor treatment response is essential to improving survival for patients with ovarian malignancies. Several serum tumor markers (STMs)-including cancer antigen 125 (CA-125), human epididymis protein 4 (HE4), cancer antigen 19-9 (CA 19-9), and carcinoembryonic antigen (CEA)-have been used as a noninvasive method of identifying ovarian cancer in conjunction with imaging. Although current guidelines do not recommend use of STMs as screening tools for ovarian cancer, these markers have clinical utility in both diagnosis and surveillance for women with ovarian cancer. CA-125 is the most commonly used STM; its level may be elevated in several types of ovarian cancer, including epithelial cell tumors, carcinosarcoma, teratomas, and secondary ovarian malignancies. An elevated level of CA 19-9 is associated with clear cell tumors, teratomas, and secondary malignancies. CEA is most commonly associated with mucinous ovarian cancers. Finally, HE4 is being increasingly used to identify certain subtypes of epithelial ovarian cancers, particularly serous and endometrioid tumors. Diagnosis of ovarian cancers relies on a combination of CA-125 levels and US findings, which include a large adnexal mass or high-risk features, including septa and increased vascularity. CT is preferred for staging and is used along with PET and STM monitoring for surveillance. Increasingly, MRI is being used to characterize ovarian lesions that are indeterminate at US or CT. The future of STM testing involves development of "liquid biopsies," in which plasma samples are analyzed for evidence of tumors, including circulating tumor DNA or tumor cells and tumor micro-RNA. When combined with traditional imaging techniques, liquid biopsies may lead to earlier diagnosis and improved survival. An invited commentary by Shinagare is available online. ©RSNA, 2021.

High-dose interleukin-2 therapy related adverse events and implications on imaging.

High-dose interleukin-2 (HDIL-2) therapy was initially approved by the U.S. Food and Drug Administration for metastatic renal cell carcinoma (mRCC) and metastatic melanoma. IL-2 is able to promote CD8+ T cell and natural killer (NK) cell cytotoxicity to increase tumoricidal activity of the innate immune system. HDIL-2 therapy is associated with a wide spectrum of immune-related adverse events (irAEs) that can be radiologically identified. HDIL-2 toxicity can manifest in multiple organ systems, most significantly leading to cardiovascular, abdominal, endocrine, and neurological adverse events. The collective impact of the irAEs and the rise of immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors led to the demise of HDIL-2 as a primary therapy for mRCC and metastatic melanoma. However, with innovation in ICIs and the creation of mutant IL-2 conjugates, there has been a drive for combination therapy. Knowledge of the HDIL-2 therapy and HDIL-2 related adverse events with radiology relevance is critical in diagnostic image interpretation.

Perceptions of porta-celiac vascular models for hepatic surgery and their use in residency training.

BACKGROUND: Primary aspect of hepatic navigation surgery is the identification of source vascular details to preserve healthy liver which has a vascular anatomy quite challenging for the young surgeons. The purpose was to determine whether three-dimensional (3D) vascular pattern models of preoperative computed tomography (CT) images will assist resident-level trainees for hepatic surgery. METHODS: This study was based on the perception of residents who were presented with 5 different hepatic source vascular patterns and required to compare their perception level of CT, and 1:1 models in terms of importance of variability, differential of patterns and preoperative planning. RESULTS: All residents agree that models provided better understanding of vascular source and improved preplanning. Five stations provided qualitative assessment with results showing the usefulness of porta-celiac models when used as anatomical tools in preplanning (p = 0.04), simulation of interventional procedures (p = 0.02), surgical education (p = 0.01). None of the cases had scored less than 8.5. Responses related to understanding variations were significantly higher in the perception of the 3D model in all cases, furthermore 3D models were more useful for seniors in more complex cases 3 and 5. Some open-ended answers: "The 3D model can completely change the operation plan" One of the major factors for anatomical resection of liver transplantation is the positional relationship between the hepatic arteries and the portal veins. CONCLUSION: The plastic-like material presenting the hepatic vascularity enables the visualization of the origin, pattern, shape, and angle of the branches with appropriate spatial perception thus making it well-structured.

Patient-centered oncosurgical planning with cancer models in subspecialty education.

BACKGROUND: A fundamental aspect of oncosurgical planning in organ resections is the identification of feeder vessel details to preserve healthy organ tissue while fully resecting the tumors. The purpose of this study was to determine whether three-dimensional (3D) cancer case models of computed tomography (CT) images will assist resident-level trainees in making appropriate operative plans for organ resection surgery. METHODS: This study was based on the perception of surgery residents who were presented with 5 different oncosurgical scenarios. A five-station carousel including cases of liver mass, stomach mass, annular pancreas, pelvic mass and mediastinal mass was formed for the study. The residents were required to compare their perception level of the cases with their CT images, and 3D models in terms of identifying the invasion of the mass, making differential diagnosis and preoperative planning stage. RESULTS: All residents have given higher scores for models. 3D models provided better understanding of oncopathological anatomy and improved surgical planning. In all scenarios, 70-80% of the residents preferred the model for preoperative planning. For surgical choice, compared to the CT, the model provided a statistically significant difference in terms of visual assessment, such as tumor location, distal or proximal organotomy (p:0.009). In the evaluation of presacral mass, the perception of model was significantly better than the CT in terms of bone-foramen relationship of chondrosarcoma, its origin, geometric shape, localization, invasion, and surgical preference (p:0.004). The model statistically significantly provided help to evaluate and prepare the case together with the colleagues performing surgery (p:0.007). Commenting on the open-ended question, they stated that the tumor-vessel relationship was clearly demonstrated in the 3D model, which has been very useful. CONCLUSIONS: With the help of 3D printing technology in this study, it is possible to implement and evaluate a well-structured real patient scenario setup in cancer surgery training. It can be used to improve the understanding of pathoanatomical changes of multidisciplinary oncologic cases. Namely, it is used in guiding the surgical strategy and determining whether patient-specific 3D models change pre-operative planning decisions made by surgeons in complex cancer mass surgical procedures.

Unintentional weight loss: what radiologists need to know and what clinicians want to know.

Unintentional weight loss (UWL) is a common presenting symptom with a wide differential diagnosis. Causes may be organic (e.g., malignancy or gastrointestinal disease) or inorganic (e.g., psychosocial). The purpose of this review is to provide a guide for radiologists and other clinicians to understand the imaging modalities and laboratory studies involved in the diagnosis and treatment of UWL and the evidence supporting their routine use. Cases illustrating both common and uncommon causes of UWL are presented to emphasize both the breadth of pathology that may cause UWL as well as the importance of a multi-modality diagnostic approach. Imaging studies are crucial in the diagnosis of unintentional weight loss, particularly with regard to evaluating for the presence of malignancy. It is important for both the radiologist and other clinicians to understand the relative prevalence of the various causes of UWL and the utility of different imaging modalities in diagnosis and management.

Findings on Chest CT Performed in the Emergency Department in Patients Receiving Immune Checkpoint Inhibitor Therapy: Single-Institution 8-Year Experience in 136 Patients.

BACKGROUND. Patients undergoing immune checkpoint inhibitor (ICI) therapy may present to the emergency department (ED) with a wide range of immune-related adverse events. OBJECTIVE. The purpose of our study was to evaluate chest CT findings in patients receiving ICI therapy presenting to the ED and to explore these findings' associations with clinical parameters. METHODS. This retrospective study included 136 patients (75 men, 61 women; mean age, 65 ± 12 [SD] years) receiving ICI therapy who underwent chest CT at 163 ED visits between 2011 and 2018. Two radiologists independently reviewed chest CT examinations for various findings and resolved discrepancies by consensus. Clinical parameters, including survival at last available follow-up, were recorded. Chest CT findings were summarized, and interreader agreement was evaluated using kappa coefficients. Associations between CT findings and clinical parameters were explored using Fisher exact, chi-square, Wilcoxon, and Kruskal-Wallis tests. RESULTS. A total of 62.5% of patients had primary lung cancer; 52.9% received nivolumab monotherapy, and 30.1% received pembrolizumab monotherapy. A total of 55.8% of ED visits occurred within 60 days after ICI initiation. The most common CT findings were worsening lung tumor burden (60.1%), new consolidation unrelated to tumor (30.1%), new or worsening pleural effusion (23.9%), and ICI-associated pneumonitis (12.9%). The most common CT pneumonitis pattern was radiation recall pneumonitis (6/21, 28.6%). A total of 78.5% of ED visits with chest CT resulted in hospitalization; 66.9% of patients subsequently died. Survival was worse for patients with, versus without, worsening tumor (72.2% vs 49.1% of patients deceased vs alive at follow-up, p = .006) and for patients with, versus without, pleural effusion (39.2% vs 17.5% of patients deceased vs alive at follow-up, p = .04). Kappa values for interreader agreement of evaluated chest CT findings ranged from 0.66 (worsening tumor burden) to 1.00 (numerous findings). CONCLUSION. Most ED chest CT examinations in patients receiving ICI therapy exhibited worsening lung tumor burden, which was associated with worse survival. New consolidation and ICI-associated pneumonitis (most commonly radiation recall pneumonitis) were also commonly detected in the ED setting. CLINICAL IMPACT. Understanding pathologies detected on chest CT in patients undergoing ICI therapy who present to the ED may guide radiologists in interpreting such imaging.

Dual-energy CT enterography in evaluation of Crohn's disease: the role of virtual monochromatic images.

PURPOSE: To assess the use of virtual monochromatic images (VMI) for discrimination of affected and non-affected bowel walls in patients with Crohn's disease (CD) as well as to compare mural enhancement between patients with and without CD. MATERIALS AND METHODS: This retrospective study included 61 patients (47 with CD, 14 without CD). Attenuation value (AV), signal-to noise ratio (SNR), and contrast-to-noise ratio (CNR) were obtained at VMI energy levels from 40 to 110 keV in 10 keV increment. Analyses were performed among affected and non-affected bowel walls in CD patients, as well as from bowel walls in patients without CD. Image quality and mural enhancement were evaluated at VMI energy levels at 40, 70, and 110 keV. RESULTS: At all energy levels of VMI, each quantitative data for AV, SNR, and CNR showed statistically significant difference between diseased and non-diseased bowel walls in CD patients. In the quantitative assessment of patients with and without CD, the optimal AV and SNR were obtained at 40 keV, and the optimal CNR was obtained at 70 keV. For the qualitative assessment, the best image quality and mural enhancement were obtained at 70 keV and 40 keV, respectively. CONCLUSION: VMI are helpful for the differentiation of affected bowel walls in CD patients, providing high diagnostic accuracy.

Multiparametric Prostate Magnetic Resonance Imaging Before Radical Prostatectomy: Can it Predict Histopathology?

PURPOSE: We aimed to investigate the histopathological correlation of the suspected prostate malignancy detected in multiparametric prostate magnetic resonance imaging (mpMRI). MATERIALS AND METHODS: The data of 93 patients underwent radical prostatectomy and had preoperative mpMRI were examined. Age and pre-operative Prostate-Specific Antigen value were retrospectively collected from patient files. The pathology specimens were examined again and post-operative ISUP grade group, other pathological findings (seminal vesicle invasion, lymph node involvement and extraprostatic extension), pre-operative mpMRI were re-examined and PIRADS score, extracapsular extension, seminal vesicle invasion, neurovascular bundle invasion, lymph node involvement and ADC values were recorded. RESULTS: 151 (92,07%) of 164 lesions detected in mpMRI were histopathologically correlated. 80% of patients with seminal vesicle invasion (P < 0.001), 28.8% of patients with extracapsular extension (P < 0.052) and 42.9% of patients with lymph node involvement (P = .001) in mpMRI were histopathologically correlated. A significant relationship was found between PIRADS scores and ISUP grade groups (P < 0.001). There was a negative correlation between ADC values and ISUP grade groups (P < 0.001). CONCLUSION: Our study showed that the lesions detected by mpMRI showed a high histopathological correlation.

Imaging features of gastrointestinal toxicity in non-small cell lung cancer patients treated with erlotinib: A single institute 13-year experience.

OBJECTIVES: To investigate the imaging features of erlotinib-associated gastrointestinal toxicity (GT) in patients with non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: The electronic medical records of 157 patients with NSCLC who received erlotinib between 2005 and 2018 were retrospectively reviewed to identify patients with GT. Clinical and radiologic evidence of erlotinib-associated GT was evaluated. Imaging findings were cross-referenced with clinical presentation, management, and outcomes. RESULTS: 24 (15%) patients (16 women; median age, 68 years) with radiologic evidence of GT were identified. The median time to detection of GT on imaging was 4.5 months (range: 0-58 months). 3/24 (12.5%) patients had no clinical symptoms, but GT was radiologically identified. Erlotinib-associated GT manifested in the large bowel in either a diffuse (42%) or segmental (58%) pattern. The most common imaging finding was fluid-filled bowel (23/24, 96%). CONCLUSION: Erlotinib-associated GT was identified in 15% patients with NSCLC. Fluid-filled colon and segmental involvement were the most common imaging manifestations.

Surgical planning with patient-specific three-dimensional printed pancreaticobiliary disease models - Cross-sectional study.

BACKGROUND: Three-dimensional (3D) printing has been increasingly used in medical applications with the creation of accurate patient-specific 3D printed models in medical imaging data. This study has been planned based on the fact that research on 3D printing in pancreaticobiliary disease is limited due to lack of studies on validation of model accuracy. METHODS: This is an innovative study where general surgery residents are presented 5 distinct hepatopancreatobiliary disease scenarios to generate a perception and required to compare their perception level of these cases with magnetic resonance cholangiopancreatography (MRCP), 3D images and 1:1 solid models that the pathology, diverse diagnosis and presurgery diagnosis stages can be observed. This study is single-centered. RESULTS: The dilated pancreaticobiliary intervention based on scenarios for general surgery residency was more original since there was no prior study that includes both model building and the evaluation of the perception created by the model. Five scenarios provided qualitative assessment with results showing the usefulness of 3D models when used as clinical tools in preoperative planning, simulation of interventional procedures, surgical education, and training. The perception level in the 3D model, MRCP (Z: 3.854, p: 0.000) and the 3D image (Z: 2.865, p: 0.004) was higher; likewise, the 3D-STL image was higher compared to the MRCP image (Z: 3.779, p: 0.000). All subspecialists agree that 3D models provided better understanding of dilated pancreaticobiliary pathoanatomy and improved surgical planning. CONCLUSIONS: A thoroughly outlined genuine patient situation layout aimed for general surgery training can be installed and monitored with the support of 3D printing technology of this study. This can be utilized to develop the comprehension of pathoanatomical variations of complex pancreaticobiliary illness and to adopt a surgical approach.

Clinical, Imaging Findings, Responses, and Outcomes of Patients With Classical Hodgkin Lymphoma and Non-Hodgkin Lymphoma Undergoing Immune Checkpoint Inhibitor Therapy: A Single-Institution Experience.

OBJECTIVE: The aim of the study was to study clinical, imaging findings, response patterns, and immune-related adverse events in classical Hodgkin lymphoma (cHL) and non-Hodgkin lymphoma (NHL) patients treated with immune checkpoint inhibitors (ICIs). METHODS: A retrospective search was performed to identify patients with relapsed/refractory cHL and NHL treated with ICIs from 2015 to 2019. Clinical and laboratory data were collected. Imaging studies were reviewed for treatment response and immune-related adverse events. RESULTS: Ten patients with relapsed/refractory cHL (median age, 41 years) and 14 patients with relapsed/refractory NHL (median age, 61 years) were identified. Overall response rate was 70% for cHL patients. None of the NHL patients demonstrated complete or partial response. One case of hyperprogression and one case with atypical response were radiologically detected in cHL patients. Hypothyroidism requiring treatment occurred in 2 (20%) of 10 cHL patients, one of which had imaging correlate. Of 14 NHL patients, 1 (7%) had radiologic evidence of pneumonitis and 1 (7%) had colitis. CONCLUSIONS: This single-institution observational study demonstrated that overall response rate was higher in patients with cHL undergoing ICI. Immune checkpoint inhibitor therapy has unique response patterns and toxicities in both cHL and NHL patients that radiologists should keep in mind.

Intracellular localization of beta-catenin expression plays a possible prognostic role on the outcome of hepatoblastoma patients.

PURPOSE: Wnt/Beta-catenin pathway plays an essential role in liver development and regeneration. Abnormal activation in this pathway leads to development of hepatoblastoma (HB). Although its importance has invoked attention, its prognostic role is debatable. We aimed to evaluate the significance of intracellular localization of beta-catenin (BC) expression in the outcome of hepatoblastoma patients. METHODS: Medical records of HB patients between 2004 and 2018 were reviewed. Patients were grouped according to intracellular localization of BC expression by immunohistochemistry as being cytoplasmic or nuclear. Demographics, radiological images, PRETEXT classifications, vascular involvement, risk groups, chemotherapy responses, and survival rates were analyzed and compared between groups. RESULTS: There were 41 patients. Thirteen patients were excluded for unavailability of records in four, negative/unclear BC expressions in seven. Cytoplasmic expression of BC was observed in 17 patients whereas 13 patients displayed nuclear expression. Demographics were similar in both groups. Cytoplasmic BC expression was associated with poor chemotherapy response (p = 0.001) and increased vascular involvement (p = 0.0162) requiring more extensive surgeries (p = 0.039). CONCLUSION: Although the numbers are limited in our series, the intracellular localization of BC expression has been found to be a promising determining factor for hepatoblastoma prognosis. With larger patient series, more reliable results can be achieved.

Extraprostatic extension in prostate cancer: primer for radiologists.

The presence of extraprostatic extension (EPE) on multiparametric MRI (mpMRI) is an important factor in determining the management of prostate cancer. EPE is an established risk factor for biochemical recurrence of prostate cancer after radical prostatectomy (RP) and patients with EPE may be considered for wider resection margins, non-nerve-sparing surgery, adjuvant radiation therapy (RT), or androgen deprivation therapy (ADT). Several statistical nomograms and scoring systems have been developed to predict pathological stage at time of RP but with varying accuracies. Using the current PI-RADS v2 mpMRI staging guidelines results in high specificity but lacks in sensitivity. These findings reveal the need for more standardization and further refinement of existing MRI protocols and prostate cancer prediction tools. Current studies have looked into indirect additional imaging criteria such as index tumor volume, length of capsular contact, and apparent diffusion coefficient. Measuring for these features can improve the robustness of mpMRI in staging prostate cancer, as they have been shown to be independent predictors of EPE. MRI/ultrasound fusion-guided targeted biopsy can detect EPE not found on standard biopsy. Collectively, these measurements and imaging techniques can augment the detection of EPE and subsequent risk stratification.

The Role of Imaging and Systemic Treatments in Myeloma: A Primer for Radiologists.

OBJECTIVE. The purpose of this article is to provide an up-to-date guide for radiologists on imaging and systemic therapies in myeloma and related conditions, with a focus on radiologic findings for diagnosis and treatment response assessment. CONCLUSION. Knowledge of the unique imaging presentations of myeloma is highly useful for radiologists. An understanding of the utility of different imaging modalities and the systemic therapies used in multiple myeloma is also critical in the realm of oncologic imaging.

Clinical, imaging, endoscopic findings, and management of patients with CMV colitis: a single-institute experience.

PURPOSE: To evaluate clinical, laboratory, imaging, endoscopic findings, treatment, and outcomes of patients with CMV colitis. METHODS: The electronic medical records of 652 patients who had an impression of colitis of unspecified etiology via endoscopic findings between 2011 and 2019 were retrospectively reviewed. There were 9 patients with biopsy-proven CMV colitis and associated CT imaging performed within 1 month of diagnosis. Demographic data, past medical history, symptoms, laboratory, imaging, endoscopic and biopsy findings, colitis-related adverse events, treatment, and management were recorded. RESULTS: Within the group of 9 patients (2 men; median age, 60 years), all were in an immunosuppressed state (8/9 on immunosuppressive medication regimen and 1/9 with untreated AIDS). Presenting symptoms of CMV colitis included bloody stools (9/9), abdominal pain (7/9), and diarrhea (7/9). The most common imaging findings were pericolonic stranding (9/9) and bowel wall thickening (9/9). Endoscopic evaluation noted inflammation (9/9), ulceration (9/9), and erythema (8/9) as the most prevalent impressions. As determined by both imaging and endoscopy, the sigmoid colon was most commonly affected. Patients were treated with valganciclovir alone (3/9) or ganciclovir followed by valganciclovir (6/9). Outcomes included perforated colon (1/9), persistent colitis (3/9), discharge to hospice (1/9), and resolution (4/9). CONCLUSIONS: CMV colitis is generally associated with an immunosuppressed state. Imaging and endoscopic findings can mimic inflammatory, ischemic, and infectious colitides. However, CMV colitis should be included in the differential diagnosis in immunocompromised adults who present to emergency department with bloody stools, acute abdominal pain or diarrhea, and have bowel wall thickening and pericolonic stranding on imaging.

Overview of imaging findings associated with systemic therapies in advanced epithelial ovarian cancer.

PURPOSE: To provide an overview for radiologists of the systemic agents used in the treatment of advanced epithelial ovarian cancer (EOC) and their associated toxicities. RESULTS: EOC is a common gynecological malignancy, with the majority of patients presenting with advanced stage disease at the time of diagnosis. Although primary cytoreductive surgery and chemotherapy are the principal treatments for EOC, recurrence rates of disease remain high. As several molecular targeted therapies have been developed in the last decade, various novel agents have shown efficacy in the treatment of advanced EOC. Advanced EOC will be discussed by outlining the relevant radiological features of toxicities. CONCLUSION: Knowledge of the systemic therapies utilized in the treatment of advanced EOC and their associated radiological features is critical in diagnostic image interpretation.

Hemophagocytic Lymphohistiocytosis: A Primer for Radiologists.

OBJECTIVE. The purpose of this article is to provide for radiologists an overview of the radiologic, clinical, and pathologic features of hemophagocytic lymphohistiocytosis. CONCLUSION. Hemophagocytic lymphohistiocytosis is a rare, life-threatening syndrome characterized by abnormal, excessive activation of the immune system. Imaging plays an important role in determining the extent of involvement of hemophagocytic lymphohistiocytosis. Knowledge of this entity, including its imaging, clinical, and pathologic findings, is critical to facilitate timely diagnosis.

Imaging and clinical manifestations of immune checkpoint inhibitor-related colitis in cancer patients treated with monotherapy or combination therapy.

PURPOSE: To determine the frequency, imaging, and clinical manifestations of immune checkpoint inhibitor (ICI)-related colitis in cancer patients on monotherapy or combination therapy. METHODS: The electronic medical records of 1044 cancer patients who received ICIs were retrospectively reviewed to identify 48 patients who had a clinical diagnosis of immune-related colitis. Imaging studies were reviewed to identify patients with imaging manifestations of colitis. Demographic data, type of ICIs, symptoms, presence of other immune-related adverse events (irAEs), and management were recorded. RESULTS: There was imaging evidence of immune-related colitis in 34 patients (24 men; median age: 63.5 years). The median time to onset of colitis was 75 days (IQR 25-75, 49.5-216 days) in patients receiving monotherapy (group 1) and 78 days (IQR 25-75, 44.3-99.5 days) in patients undergoing combination therapy (group 2) following start of ICI. Symptoms included diarrhea (91.1% [31 of 34]), nausea/vomiting (52.9% [18 of 34]), and abdominal pain (52.9% [18 of 34]). The most common imaging findings were bowel wall thickening (97% [33 of 34]) and fluid-filled colon (82.3% [28 of 34]). Colitis was diffuse in 21 of 34 (61.8%) patients. Imaging manifestations did not differ between the two groups (p > 0.05). Steroids and antibiotics were used to treat colitis in 29 of 34 (85.2%) and 13 of 34 (38.2%) patients, respectively. No patients in group 1 experienced concurrent irAEs, but 5 of 18 (27.8%) of patients in group 2 had other irAEs (p = 0.046). CONCLUSION: Immune-related colitis occurred in 3.3% of patients receiving ICIs with bowel wall thickening, fluid-filled colon and pancolitis being the most common imaging manifestations. Imaging manifestations did not differ between patients receiving monotherapy or combination therapy. However, concurrent irAEs were significantly observed in patients undergoing combination therapy.

Characterization of adrenal lesions on chemical shift MRI: comparison of 1.5 T and 3 T MRI.

PURPOSE: To compare three chemical shift MRI techniques [two-dimensional (2D) dual gradient echo (dGRE), 3D VIBE, and 3D VIBE-Dixon] at 3 T and 2D dGRE technique at 1.5 T to assess their ability of detecting microscopic fat in adrenal adenomas and differentiating between adenomas and non-adenomas. METHODS: Seventy-eight patients with 97 lesions (78 adenomas, 19 non-adenomas) underwent both 1.5 T and 3 T chemical shift MRI. The Wilcoxon signed-ranked test was used to determine if there was significant difference between the signal intensity index (SII) values of each technique to assess their ability to detect microscopic fat in adrenal adenomas. ROC analysis was performed for the SII values of each technique, the adrenal-to-spleen SI ratio of 2D dGRE technique at 3 T, and the fat fraction values of the 3D VIBE-Dixon technique to identify the optimal threshold for differentiation of adrenal adenomas from non-adenomas. RESULTS: For detection of microscopic fat, the mean SII value of 2D dGRE technique at 1.5 T was significantly higher than that of the chemical shift imaging techniques at 3 T (p = 0.001). For discrimination of adenomas from non-adenomas, the area under the curve (AUC) and 95% confidence interval values of 2D dGRE technique at 1.5 T and 2D dGRE, 3D VIBE, 3D VIBE-Dixon techniques at 3 T were calculated as 1.00 (1.00-1.00), 0.991 (0.978-1.00), 0.999 (0.995-1.00), 0.993 (0.979-1.00), respectively, for the SII. CONCLUSION: Chemical shift MRI at 1.5 T using the 2D dGRE technique provided the most accurate differentiation between adenomas and non-adenomas. However, there was no statistically significant difference between chemical shift imaging techniques at 1.5 T and 3 T.