CT and MRI of Gastrointestinal Stromal Tumors: New Trends and Perspectives.

Gastrointestinal stromal tumors (GISTs) are defined as mesenchymal tumors of the gastrointestinal tract that express positivity for CD117, which is a c-KIT proto-oncogene antigen. Expression of the c-KIT protein, a tyrosine kinase growth factor receptor, allows the distinction between GISTs and other mesenchymal tumors such as leiomyoma, leiomyosarcoma, schwannoma and neurofibroma. GISTs can develop anywhere in the gastrointestinal tract, as well as in the mesentery and omentum. Over the years, the management of GISTs has improved due to a better knowledge of their behaviors and risk or recurrence, the identification of specific mutations and the use of targeted therapies. This has resulted in a better prognosis for patients with GISTs. In parallel, imaging of GISTs has been revolutionized by tremendous progress in the field of detection, characterization, survival prediction and monitoring during therapy. Recently, a particular attention has been given to radiomics for the characterization of GISTs using analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence with the aim of better characterizing GISTs and providing a more precise assessment of tumor burden. This article sums up recent advances in computed tomography and magnetic resonance imaging of GISTs in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning.

Bowel Emergencies in Patients With Cancer.

Cancer is the second most common cause of death worldwide. Bowel emergencies in patients with cancer are becoming increasingly more prevalent due to advances in cancer therapy and longer overall patient survival. When these patients present acutely, they are often frail and may have pre-existing co-morbidities. This article discusses the imaging features of bowel emergencies commonly encountered in oncological patients in clinical practice. These include chemotherapy related colitis, neutropenia enterocolitis and typhlitis, toxic megacolon, bowel perforation, malignant bowel obstruction and gastrointestinal haemorrhage. The radiologist plays a key role in identifying these oncological emergencies and guiding further management.

Comparison Between Radial and Femoral Artery Access for Transarterial Chemoembolisation in Patients With Hepatocellular Carcinoma.

PURPOSE: The purpose of this study was to compare the technical success rate, the selectivity of transarterial chemoembolisation (TACE), the complication rate, the radiation dose given to the patients and the hospitalization stay between TACE performed using femoral artery approach (FAA) and TACE performed using radial artery approach (RAA) in patients with hepatocellular carcinoma (HCC). METHODS: Between June 2020 and April 2022, 49 patients with HCC who underwent 116 TACEs (75 using FAA and 41 using RAA) were included. Differences in technical success rate, selectivity of micro-catheterization, radiation dose given to the patients, fluoroscopy time, hospitalization stay duration, and complication rate were compared between FAA and RAA using Fisher exact or Student t tests. RESULTS: No differences in technical success rates were found between RAA (93%; 39/41 TACEs) and FAA (100%; 75/75 TACEs) (P = .12). There were no differences between the two groups in terms of selectivity of catheterization, radiation dose, fluoroscopy time and hospitalization stay duration. Five patients had Grade 2 complications (hematoma) after FAA vs. one patient with one Grade 1 complication (radial artery occlusion) after RAA (5/75 [7%] vs. 1/41 [2%], respectively; P = .42). No major arterial access site complications occurred with FAA or RAA. CONCLUSIONS: This study confirms that RAA is a safe approach that does not compromise the technical efficacy and the selectivity of TACE compared to FAA in patients with HCC.

Interventional Oncology: 2024 Update.

Interventional Oncology (IO) stands at the forefront of transformative cancer care, leveraging advanced imaging technologies and innovative interventions. This narrative review explores recent developments within IO, highlighting its potential impact facilitated by artificial intelligence (AI), personalized medicine and imaging innovations. The integration of AI in IO holds promise for accelerating tumour detection and characterization, guiding treatment strategies and refining predictive models. Imaging modalities, including functional MRI, PET and cone beam CT are reshaping imaging and precision. Navigation, fusion imaging, augmented reality and robotics have the potential to revolutionize procedural guidance and offer unparalleled accuracy. New developments are observed in embolization and ablative therapies. The pivotal role of genomics in treatment planning, targeted therapies and biomarkers for treatment response prediction underscore the personalization of IO. Quality of life assessment, minimizing side effects and long-term survivorship care emphasize patient-centred outcomes after IO treatment. The evolving landscape of IO training programs, simulation technologies and workforce competence ensures the field's adaptability. Despite barriers to adoption, synergy between interventional radiologists' proficiency and technological advancements hold promise in cancer care.

Artificial intelligence vs. radiologist: accuracy of wrist fracture detection on radiographs.

OBJECTIVE: To compare the performances of artificial intelligence (AI) to those of radiologists in wrist fracture detection on radiographs. METHODS: This retrospective study included 637 patients (1917 radiographs) with wrist trauma between January 2017 and December 2019. The AI software used was a deep neuronal network algorithm. Ground truth was established by three senior musculoskeletal radiologists who compared the initial radiology reports (IRR) made by non-specialized radiologists, the results of AI, and the combination of AI and IRR (IR+AI) RESULTS: A total of 318 fractures were reported by the senior radiologists in 247 patients. Sensitivity of AI (83%; 95% CI: 78-87%) was significantly greater than that of IRR (76%; 95% CI: 70-81%) (p < 0.001). Specificities were similar for AI (96%; 95% CI: 93-97%) and for IRR (96%; 95% CI: 94-98%) (p = 0.80). The combination of AI+IRR had a significantly greater sensitivity (88%; 95% CI: 84-92%) compared to AI and IRR (p < 0.001) and a lower specificity (92%; 95% CI: 89-95%) (p < 0.001). The sensitivity for scaphoid fracture detection was acceptable for AI (84%) and IRR (80%) but poor for the detection of other carpal bones fracture (41% for AI and 26% for IRR). CONCLUSIONS: Performance of AI in wrist fracture detection on radiographs is better than that of non-specialized radiologists. The combination of AI and radiologist's analysis yields best performances. KEY POINTS: • Artificial intelligence has better performances for wrist fracture detection compared to non-expert radiologists in daily practice. • Performance of artificial intelligence greatly differs depending on the anatomical area. • Sensitivity of artificial intelligence for the detection of carpal bones fractures is 56%.

CT-based diagnostic algorithm to identify bowel and/or mesenteric injury in patients with blunt abdominal trauma.

OBJECTIVES: To develop a CT-based algorithm and evaluate its performance for the diagnosis of blunt bowel and/or mesenteric injury (BBMI) in patients with blunt abdominal trauma. METHODS: This retrospective study included a training cohort of 79 patients (29 with BBMI and 50 patients with blunt abdominal trauma without BBMI) and a validation cohort of 37 patients (13 patients with BBMI and 24 patients with blunt abdominal trauma without BBMI). CT examinations were blindly analyzed by two independent radiologists. For each CT sign, the kappa value, sensitivity, specificity, and accuracy were calculated. A diagnostic algorithm was built using a recursive partitioning model on the training cohort, and its performances were assessed on the validation cohort. RESULTS: CT signs with kappa value > 0.6 were extraluminal gas, hemoperitoneum, no or moderate bowel wall enhancement, and solid organ injury. CT signs yielding best accuracies in the training cohort were extraluminal gas (98%; 95% CI: 91-100), bowel wall defect (97%; 95% CI: 91-100), irregularity of mesenteric vessels (97%; 95% CI: 90-99), and mesenteric vessel extravasation (97%; 95% CI: 90-99). Using a recursive partitioning model, a decision tree algorithm including extraluminal gas and no/moderate bowel wall enhancement was built, achieving 86% sensitivity (95% CI: 74-99) and 96% specificity (95% CI: 91-100) in the training cohort and 92% sensitivity (95% CI: 78-97) and 88% specificity (95% CI: 74-100) in the validation cohort for the diagnosis of BBMI. CONCLUSIONS: An effective diagnostic algorithm was built to identify BBMI in patients with blunt abdominal trauma using only extraluminal gas and no/moderate bowel wall enhancement on CT examination. KEY POINTS: • A CT diagnostic algorithm that included extraluminal gas and no/moderate bowel wall enhancement was built for the diagnosis of surgical blunt bowel and/or mesenteric injury. • A decision tree combining only two reproducible CT signs has high diagnostic performance for the diagnosis of surgical blunt bowel and/or mesenteric injury.

Intra-Specialty Citation Pattern in Radiology and Gastroenterology/Hepatology Journals: A Cross-Specialty Comparison.

Objectives: To investigate intra-specialty citation patterns of radiology articles, compared with another medical specialty: gastroenterology/hepatology. Methods: Four radiology journals (Radiology, European Radiology, Diagnostic and Interventional Imaging, Canadian Association of Radiologists Journal) and four gastroenterology/hepatology journals (Journal of Hepatology, Journal of Gastroenterology, World Journal of Gastroenterology, Journal of Clinical Gastroenterology) with similar Web of Science in-category 2020 IF ranking were selected. The original research, review, letter, and editorial articles published in these journals in 2021 were identified. The average number of intra-specialty citations per article (intra-specialty citation count) and percentage of intra-specialty citations out of total citations per article (intra-specialty citation rate) were compared between radiology and gastroenterology/hepatology articles using Student's t-test. Results: The radiology articles demonstrated a lower total citation count per article (radiology: 29.7 ± .4 (mean ± SEM), n = 2063; gastroenterology/hepatology: 50.1 ± 1.4, n = 1335). The intra-specialty citation count was also lower in radiology articles than gastroenterology/hepatology articles (radiology: 12.9 ± .2, gastroenterology/hepatology: 19.6 ± .7; P < .001), both overall and in all article types. Additionally, the overall intra-specialty citation rate was not significantly different between the two specialties (radiology: 48.8% ± .5%; gastroenterology/hepatology: 47.1 ± .8%; P = .057), although the intra-specialty citation rates were higher in radiology original research and editorial article types. Conclusions: The significantly lower per-article intra-specialty citation counts in all radiology article types, a measurement that directly links to specialty IFs, may contribute to the lower impact factors of radiology journals compared with gastroenterology/hepatology ones.

Imaging of Pancreatic Ductal Adenocarcinoma: An Update on Recent Advances.

Pancreatic ductal carcinoma (PDAC) is one of the leading causes of cancer-related death worldwide. Computed tomography (CT) remains the primary imaging modality for diagnosis of PDAC. However, CT has limitations for early pancreatic tumor detection and tumor characterization so that it is currently challenged by magnetic resonance imaging. More recently, a particular attention has been given to radiomics for the characterization of pancreatic lesions using extraction and analysis of quantitative imaging features. In addition, radiomics has currently many applications that are developed in conjunction with artificial intelligence (AI) with the aim of better characterizing pancreatic lesions and providing a more precise assessment of tumor burden. This review article sums up recent advances in imaging of PDAC in the field of image/data acquisition, tumor detection, tumor characterization, treatment response evaluation, and preoperative planning. In addition, current applications of radiomics and AI in the field of PDAC are discussed.

Interobserver Variability and Accuracy of Preoperative CT and MRI in Pancreatic Ductal Adenocarcinoma Size Estimation: A Retrospective Cohort Study.

Purpose: To assess interobserver variability and accuracy of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) in pancreatic ductal adenocarcinoma (PDAC) size estimation using surgical specimens as standard of reference. Methods: Patients with PDAC who underwent preoperative CT and MRI examinations before surgery were included. PDAC largest axial dimension was measured by 2 readers on 8 MRI sequence and 2 CT imaging phases (pancreatic parenchymal and portal venous). Measurements were compared to actual tumour size at pathologic examination. Interobserver variability was assessed using intraclass correlation coefficients (ICC) and Bland-Altman plots. Differences in tumour size (Δdiameter) between imaging and actual tumour size were searched using Wilcoxon rank sum test. Results: Twenty-nine patients (16 men; median age, 70 years) with surgically resected PDAC were included. Interobserver reproducibility was good to excellent for all MRI sequences and the 2 CT imaging phases with ICCs between .862 (95%CI: .692-.942) for fat-saturated in-phase T1-weighted sequence and .955 (95%CI: .898-.980) for portal venous phase CT images. Best accuracy in PDAC size measurement was obtained with pancreatic parenchymal phase CT images with median Δdiameters of -2 mm for both readers, mean relative differences of -9% and -6% and no significant differences with dimensions at histopathological analysis (P = .051). All MRI sequences led to significant underestimation of PDAC size (median Δdiameters, -6 to -1 mm; mean relative differences, -21% to -11%). Conclusions: Most accurate measurement of PDAC size is obtained with CT images obtained during the pancreatic parenchymal phase. MRI results in significant underestimation of PDAC size.

Cinematic Rendering of Gastrointestinal Stromal Tumors: A Review of Current Possibilities and Future Developments.

Gastrointestinal stromal tumors (GISTs) are defined as CD117-positive primary, spindled or epithelioid, mesenchymal tumors of the gastrointestinal tract, omentum, or mesentery. While computed tomography (CT) is the recommended imaging modality for GISTs, overlap in imaging features between GISTs and other gastrointestinal tumors often make radiological diagnosis and subsequent selection of the optimal therapeutic approach challenging. Cinematic rendering is a novel CT post-processing technique that generates highly photorealistic anatomic images based on a unique lighting model. The global lighting model produces high degrees of surface detail and shadowing effects that generate depth in the final three-dimensional display. Early studies have shown that cinematic rendering produces high-quality images with enhanced detail by comparison with other three-dimensional visualization techniques. Cinematic rendering shows promise in improving the visualization of enhancement patterns and internal architecture of abdominal lesions, local tumor extension, and global disease burden, which may be helpful for lesion characterization and pretreatment planning. This article discusses and illustrates the application of cinematic rendering in the evaluation of GISTs and the unique benefit of using cinematic rendering in the workup of GIST with a specific emphasis on tumor characterization and preoperative planning.

Development and Validation of Multiparametric MRI-based Radiomics Models for Preoperative Risk Stratification of Endometrial Cancer.

Background Stratifying high-risk histopathologic features in endometrial carcinoma is important for treatment planning. Radiomics analysis at preoperative MRI holds potential to identify high-risk phenotypes. Purpose To evaluate the performance of multiparametric MRI three-dimensional radiomics-based machine learning models for differentiating low- from high-risk histopathologic markers-deep myometrial invasion (MI), lymphovascular space invasion (LVSI), and high-grade status-and advanced-stage endometrial carcinoma. Materials and Methods This dual-center retrospective study included women with histologically proven endometrial carcinoma who underwent 1.5-T MRI before hysterectomy between January 2011 and July 2015. Exclusion criteria were tumor diameter less than 1 cm, missing MRI sequences or histopathology reports, neoadjuvant therapy, and malignant neoplasms other than endometrial carcinoma. Three-dimensional radiomics features were extracted after tumor segmentation at MRI (T2-weighted, diffusion-weighted, and dynamic contrast-enhanced MRI). Predictive features were selected in the training set with use of random forest (RF) models for each end point, and trained RF models were applied to the external test set. Five board-certified radiologists conducted MRI-based staging and deep MI assessment in the training set. Areas under the receiver operating characteristic curve (AUCs) were reported with balanced accuracies, and radiologists' readings were compared with radiomics with use of McNemar tests. Results In total, 157 women were included: 94 at the first institution (training set; mean age, 66 years ± 11 [SD]) and 63 at the second institution (test set; 67 years ± 12). RF models dichotomizing deep MI, LVSI, high grade, and International Federation of Gynecology and Obstetrics (FIGO) stage led to AUCs of 0.81 (95% CI: 0.68, 0.88), 0.80 (95% CI: 0.67, 0.93), 0.74 (95% CI: 0.61, 0.86), and 0.84 (95% CI: 0.72, 0.92), respectively, in the test set. In the training set, radiomics provided increased performance compared with radiologists' readings for identifying deep MI (balanced accuracy, 86% vs 79%; P = .03), while no evidence of a difference was observed in performance for advanced FIGO stage (80% vs 78%; P = .27). Conclusion Three-dimensional radiomics can stratify patients by using preoperative MRI according to high-risk histopathologic end points in endometrial carcinoma and provide nonsignificantly different or higher performance than radiologists in identifying advanced stage and deep myometrial invasion, respectively. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Kido and Nishio in this issue.

Post-MRI transrectal micro-ultrasonography of transition zone PI-RADS > 2 lesions for biopsy guidance.

OBJECTIVE: To prospectively determine the value of post-MRI micro-ultrasonography (microUS) in the diagnosis of transition zone (TZ) significant prostate cancer (sPCa). PATIENTS AND METHODS: Eighty-four consecutive men (66 ± 6.3 years) with a mean PSA level of 10.2 ± 7.4 ng/mL and at least one TZ-PI-RADS > 2 lesion were included. All patients had MRI-directed microUS and biopsy. Sensitivity and specificity of post-MRI microUS to visualize PI-RADS > 2 TZ lesions, the cancer detection rate of TZ-sPCa, and tumor characteristics according to their visibility on microUS were evaluated. Interreader agreement for detecting microUS+ lesions was evaluated using Cohen's kappa test. RESULTS: Of the 92 PI-RADS > 2 lesions, 71 (71/92; 77%) were visible on microUS and biopsy was performed without image fusion, which was required for the 21 invisible lesions (21/92; 22.8%). TZ-sPCa detection rate was 51.1% (47/92). Sensitivity and specificity of MRI-directed microUS were 83% (39/47; 95% CI: 69.2-92.4%) and 28.9% (13/45; 95% CI: 16.4-44.3%), on a per-lesion basis and 86.4% (38/45; 95% CI: 72.6-94.8%) and 27.5% (11/40; 95% CI: 14.6-43.9%) on a per-patient basis. Visible tumors on microUS exhibited a larger volume and a lower mean ADC value than non-visible tumors (15.8 ± 5.1 vs. 12.5 ± 3.6 mm and 0.82 ± 1.1 × 103 vs. 0.9 ± 1.4 × 10-3 mm2/s) (p = 0.02). Non-visible tumors showed a heterogeneous non-specific echotexture or were masked by the shadowing caused by corpora amylacea. Interreader agreement was almost perfect (kappa = 0.88; 95% CI: 0.79-0.95). The main limitation is the single-center feature of the study. CONCLUSION: MRI-targeted transrectal microUS is effective to detect TZ-sPCa. TRUS-MRI image fusion helps overcome limitations due to TZ tissue heterogeneity. KEY POINTS: microUS can visualize the majority of MRI-detected PI-RADS > 2 TZ lesions (sensitivity = 83%). Interreader agreement of MRI-directed microUS in the detection of TZ lesions appears excellent (kappa = 0.88). In 77% of PI-RADS > 2 TZ lesions, biopsy was performed under microUS visual control. MRI fusion system was only used to overcome limitations due to tissue heterogeneity of benign prostatic hyperplasia.

Percreta score to differentiate between placenta accreta and placenta percreta with ultrasound and MR imaging.

INTRODUCTION: The objective of this study was to assess the performance of ultrasound and magnetic resonance imaging (MRI) features in helping to classify the type of placenta accreta spectrum (PAS; accreta/increta vs percreta), alone or combined in a predictive score. MATERIAL AND METHODS: We conducted a retrospective study in 82 pregnant women with PAS who underwent ultrasound and MRI examination of the pelvis before delivery (from an initial cohort of 185 women with PAS). We estimated the sensitivity, specificity and accuracy of MRI and ultrasound in the diagnosis of the type of PAS. We analyzed cesarean and imaging features using univariable logistic regression analysis. We constructed a nomogram to predict the risk of placenta percreta and validated it with bootstrap resampling, then used receiver operating characteristic curves to assess the performance of the model in distinguishing between placenta percreta and placenta accreta/increta. RESULTS: Among the 82 patients, 29 (35%) had placenta accreta/increta and 53 (65%) had placenta percreta. The best features to discriminate between placenta accreta/increta and placenta percreta with ultrasound were increased vascularization at the uterine serosa-bladder wall interface (odds ratio [OR] 7.93; 95% confidence interval [CI] 2.78-24.99; p < 0.01) and the number of lacunae without a hyperechogenic halo (OR 1.36; 95% CI 1.14-1.67; p = 0.012). Concerning MRI markers, heterogeneous placenta (OR 12.89; 95% CI 3.05-89.16; p = 0.002), dark intraplacental bands (OR 12.89; 95% CI 3.05-89.16; p = 0.002) and bladder wall interruption (OR 15.89; 95% CI 4.78-73.33; p < 0.001) had a higher OR in discriminating placenta accreta/increta from placenta percreta. The nomogram yielded areas under the curve of 0.841 (95% CI 0.754-0.927) and 0.856 (95% CI 0.767-0.945), after bootstrap resampling, for the accurate prediction of placenta percreta. CONCLUSIONS: The nomogram we developed to predict the risk of placenta percreta among patients with PAS had good discriminative capabilities. This performance and its impact on maternal morbidity should be confirmed by future prospective studies.

MR-enterography: role in the assessment of suspected anastomotic recurrence of Crohn disease after ileocolic resection.

PURPOSE: To determine the potential of magnetic resonance-enterography (MRE) in the assessment of the anastomotic status in patients with Crohn disease and prior ileocolic resection. METHODS: A total of 62 MRE examinations obtained in 52 patients with Crohn disease who had previously undergone ileocolic resection were retrospectively reviewed by two readers in consensus. MRE features (anastomotic wall thickening, wall stratification, wall enhancement pattern and degree, DWI signal intensity, ADC values, lymph nodes, comb sign and complications) were compared to clinical, endoscopic and histological findings that served as standard of reference. Sensitivity, specificity and accuracy of MRE were calculated. RESULTS: At univariate analysis, anastomotic wall thickening, anastomotic wall stratification, segmental wall enhancement, moderate wall enhancement, early and mucosal enhancement, and moderate/marked hyperintensity on diffusion-weighed imaging (DWI) were the most discriminative MRE features for differentiating between normal and abnormal anastomoses (p < 0.001 for all variables). Anastomotic wall thickening and segmental anastomotic wall enhancement were the two most sensitive and accurate MRE variables for the diagnosis of abnormal anastomosis with sensitivities of 82% (95% CI: 67-92%) and accuracies of 84% (95% CI: 72-92%). At univariate analysis, hyperintensity on DWI of the anastomotic site was the most sensitive finding for distinguishing between inflammatory recurrence and fibrostenosis (sensitivity, 89%; 95% CI: 67-99%). CONCLUSIONS: MRE provides objective and relatively specific morphological criteria that help detect abnormal ileocolic anastomosis, but performances are lower when differentiating between inflammatory recurrence and fibrostenosis. DWI may be useful in identifying pathologic anastomosis and, in particular, in distinguishing between inflammatory recurrence and fibrostenosis.

Magnetic Resonance Imaging May Be Able to Identify the Origin of Neuroendocrine Tumor Liver Metastases.

OBJECTIVES: The aim of the study was to discriminate hepatic metastases from pancreatic neuroendocrine tumors (pNET) and hepatic metastases from midgut neuroendocrine tumors (mNET) with magnetic resonance imaging (MRI). METHODS: MRI examinations of 24 patients with hepatic metastases from pNET were quantitatively and qualitatively assessed by 2 blinded readers and compared to those obtained in 23 patients with hepatic metastases from mNET. Inter-reader agreement was calculated with kappa and intraclass correlation coefficient (ICC). Sensitivity, specificity, and accuracy of each variable for the diagnosis of hepatic metastasis from pNET were calculated. Associations between variables and primary tumor (i.e., pNET vs. mNET) were assessed by univariate and multivariate analyses. A nomogram was developed and validated using an external cohort of 20 patients with pNET and 20 patients with mNET. RESULTS: Interobserver agreement was strong to perfect (k = 0.893-1) for qualitative criteria and excellent for quantitative variables (ICC: 0.9817-0.9996). At univariate analysis, homogeneity on T1-weighted images was the most discriminating variable for the diagnosis of pNET (OR: 6.417; p = 0.013) with greatest sensitivity (88%; 21/24; 95% CI: 68-97%). At multivariate analysis, tumor homogeneity on T1-weighted images (p = 0.007; OR: 17.607; 95% CI: 2.179-142.295) and target sign on diffusion-weighted images (p = 0.007; OR: 19.869; 95% CI: 2.305-171.276) were independently associated with pNET. Nomogram yielded a corrected AUC of 0.894 (95% CI: 0.796-0.992) for the diagnosis of pNET in the training cohort and 0.805 (95% CI: 0.662-0.948) in the validation cohort. CONCLUSIONS: MRI provides qualitative features that can help discriminate between hepatic metastases from pNET and those from mNET.

Surgical management of insulinoma over three decades.

BACKGROUND: This paper reports our experience of the perioperative management of patients with sporadic, non-malignant, pancreatic insulinoma. METHODS: A retrospective monocentric cohort study was performed from January 1989 to July 2019, including all the patients who had been operated on for pancreatic insulinoma. The preoperative work-up, surgical management, and postoperative outcome were analyzed. RESULTS: Eighty patients underwent surgery for sporadic pancreatic insulinoma, 50 of which were female (62%), with a median age of 50 (36-70) years. Preoperatively, the tumors were localized in 76 patients (95%). Computed tomography (CT) and magnetic resonance imaging allowed exact preoperative tumor localization in 76% of the patients (64-85 and 58-88 patients, respectively), increasing to 96% when endoscopic ultrasonography was performed. Forty-one parenchyma-sparing pancreatectomies (PSP) (including enucleation, caudal pancreatectomy, and uncinate process resection) and 39 pancreatic resections were performed. The mortality rate was 6% (n = 5), with a morbidity rate of 72%, including 24 severe complications (30%) and 35 pancreatic fistulas (44%). No differences were found between formal pancreatectomy and PSP in terms of postoperative outcome procedures. The surgery was curative in all the patients. CONCLUSION: CT used in combination with endoscopic ultrasonography allows accurate localization of insulinomas in almost all patients. When possible, a parenchyma-sparing pancreatectomy should be proposed as the first-line surgical strategy.

Early evaluation using a radiomic signature of unresectable hepatic metastases to predict outcome in patients with colorectal cancer treated with FOLFIRI and bevacizumab.

PURPOSE: The objective of this study was to build and validate a radiomic signature to predict early a poor outcome using baseline and 2-month evaluation CT and to compare it to the RECIST1·1 and morphological criteria defined by changes in homogeneity and borders. METHODS: This study is an ancillary study from the PRODIGE-9 multicentre prospective study for which 491 patients with metastatic colorectal cancer (mCRC) treated by 5-fluorouracil, leucovorin and irinotecan (FOLFIRI) and bevacizumab had been analysed. In 230 patients, computed texture analysis was performed on the dominant liver lesion (DLL) at baseline and 2 months after chemotherapy. RECIST1·1 evaluation was performed at 6 months. A radiomic signature (Survival PrEdiction in patients treated by FOLFIRI and bevacizumab for mCRC using contrast-enhanced CT TextuRe Analysis (SPECTRA) Score) combining the significant predictive features was built using multivariable Cox analysis in 120 patients, then locked, and validated in 110 patients. Overall survival (OS) was estimated with the Kaplan-Meier method and compared between groups with the logrank test. An external validation was performed in another cohort of 40 patients from the PRODIGE 20 Trial. RESULTS: In the training cohort, the significant predictive features for OS were: decrease in sum of the target liver lesions (STL), (adjusted hasard-ratio(aHR)=13·7, p=1·93×10-7), decrease in kurtosis (ssf=4) (aHR=1·08, p=0·001) and high baseline density of DLL, (aHR=0·98, p<0·001). Patients with a SPECTRA Score >0·02 had a lower OS in the training cohort (p<0·0001), in the validation cohort (p<0·0008) and in the external validation cohort (p=0·0027). SPECTRA Score at 2 months had the same prognostic value as RECIST at 6 months, while non-response according to RECIST1·1 at 2 months was not associated with a lower OS in the validation cohort (p=0·238). Morphological response was not associated with OS (p=0·41). CONCLUSION: A radiomic signature (combining decrease in STL, density and computed texture analysis of the DLL) at baseline and 2-month CT was able to predict OS, and identify good responders better than RECIST1.1 criteria in patients with mCRC treated by FOLFIRI and bevacizumab as a first-line treatment. This tool should now be validated by further prospective studies. TRIAL REGISTRATION: Clinicaltrial.gov identifier of the PRODIGE 9 study: NCT00952029.Clinicaltrial.gov identifier of the PRODIGE 20 study: NCT01900717.

MRI-directed high-frequency (29MhZ) TRUS-guided biopsies: initial results of a single-center study.

OBJECTIVES: To evaluate the ability of high-frequency (29 MHz) transrectal micro-ultrasound (microUS) as a second-look examination after biparametric MRI (bp-MRI) and to reidentify focal lesions seen on diagnostic MRI and to detect new ones METHODS: A total of 118 consecutive men (mean age, 66 ± 13 [SD] years; range, 49-93 years) with a mean prostate-specific antigen level of 11 ± 19 (SD) ng/mL (range, 2-200 ng/mL) and at least one focal lesion (MRI+) with a score > 2 on bp-MRI were included. Of these, 79/118 (66.9%) were biopsy-naïve and 102/118 (86.5%) had non-suspicious rectal examination. All patients had MRI-directed microUS-guided biopsy using a 29-MHz transducer. All lesions visible on micro-ultrasound (microUS+) were targeted without image fusion, which was only used for MRI+/microUS- lesions. Significant prostate cancer (sPCa) was defined by a Gleason score ≥ 7 or a maximum cancer core length > 3 mm. RESULTS: A total of 144 focal prostatic lesions were analyzed, including 114 (114/144, 79.2%) MRI+/microUS+ lesions, 13 MRI+/microUS- lesions (13/144, 9%), and 17 MRI-/microUS+ lesions (17/144, 11.8%). Significant PCa was detected in 70 MRI+/microUS+ lesions (70/114, 61.4%), in no MRI+/microUS- lesion (0/13, 0%), and in 4 MRI-/microUS+ lesions (4/17, 23.5%). The sensitivity and specificity of microUS on a per-patient and a per-lesion basis were 100% (95% CI, 84.9-100%) and 22.8% (95% CI, 12.5-35.8%) and 100% (95% CI, 85.1-100%) and 22.6% (95% CI, 12.3-36.2%), respectively. CONCLUSION: MicroUS, as a second-look examination, may show promise to localize targets detected on bp-MRI. KEY POINTS: • Used as a second-look examination, microUS-guided biopsies have a 100% detection rate of sCa originating in the PZ or lower third of the TZ, without microUS-MRI image fusion. • MicroUS results may provide additional information about lesions visible on MRI. • MicroUS may provide the ability to detect small PZ lesions undetected by bp-MRI.

Can we differentiate HIV-associated obliterative portopathy from liver cirrhosis using MRI?

AIM: To describe the magnetic resonance imaging (MRI) features of HIV-associated obliterative portopathy (HIV-OP) and determine the most indicative appearance of this condition on MRI by using a retrospective case-control study. METHODS: MRI examinations of 24 patients with HIV-OP (16 men, 8 women; mean age = 48 ± 6.6 [SD] years; age range, 35-71 years) were analyzed by two blinded observers and compared with those obtained in 18 HIV-infected patients with hepatic cirrhosis (14 men, 4 women; mean age = 51 ± 3.4 [SD] years; age range, 35-60 years). Images were qualitatively and quantitatively analyzed with respect to imaging presentation. Comparisons were performed using uni- and multivariate analyses. RESULTS: Regular liver contours had the highest accuracy for the diagnosis of HIV-OP (83%, 35 of 42; 95% confidence interval [CI], 69-93%) and was the most discriminating independent variable for the diagnosis of HIV-OP (odds ratio, 51; 95%CI, 4.96-1272%) (p < 0.0001). At multivariate analysis, the width of segment 4 in millimeters (OR = 1.23 [95%CI, 1.05-1.44%]; p = 0.011) and the presence of regular liver contours (OR = 7.69 [95%CI, 1.48-39.92%]; p = 0.015) were the variables independently associated with the diagnosis of HIV-OP. CONCLUSIONS: Regular liver contours are the most discriminating independent variable for the diagnosis of HIV-OP but have limited accuracy. Familiarity with this finding may help differentiate HIV-OP from cirrhosis in HIV-infected patients. KEY POINTS: • Regular liver contour is the most discriminating independent variable for the diagnosis of HIV-OP (odds ratio = 51) with 83% accuracy. • At multivariate analysis, the width of segment 4 in millimeters and the presence of regular liver contours are the variables independently associated with the diagnosis of HIV-OP. • MRI helps diagnose HIV-OP in the presence of several categorical findings, which are more frequently observed in HIV-OP patients than in HIV patients with cirrhosis.

Meglumine diatrizoate esophagogram after peroral endoscopic myotomy (POEM): identification of imaging findings associated with clinical complications and longer hospital stay.

OBJECTIVES: Esophageal peroral endoscopic myotomy (POEM) is the treatment of reference of major obstructive esophageal motility disorders but the detection of early complications remains challenging. Our aim was to report the radiological findings on meglumine diatrizoate esophagograms after esophageal POEM and identify variables associated with patient outcomes. METHODS: The imaging and clinical files of 106 patients who underwent POEM for achalasia or other major obstructive esophageal motility disorders were retrospectively analyzed. Post POEM esophagograms were reviewed for the presence of pneumoperitoneum, pleural effusion, extraesophageal contrast leakage, and dislocated clips. Associations between length of hospital stay and radiological findings were searched for using a Cox multivariate analysis. RESULTS: A total of 106 patients (M/F = 56/50; mean age = 50 ± 2 [SD] years) underwent 106 POEM procedures with a meglumine diatrizoate esophagogram on postoperative day 1. Overall median hospital stay was 3 days (range 1-20 days). Pneumoperitoneum, pleural effusion, extraesophageal contrast leakage, and dislocated clips were observed in 90/106 (84.9%), 12/106 (11.3%), 4/106 (3.8%), and 0/106 (0%) patients, respectively. At multivariate analysis, pleural effusion (p = 0.005; adjusted hazard ratio [aHR] = 0.35 [95% CI 0.17-0.73]) and extraesophageal contrast leakage (p = 0.039; aHR = 0.27 [95% CI 0.08-0.94]) were associated with a prolonged hospital stay. Pneumoperitoneum was not associated with unfavorable outcome (p = 0.99). CONCLUSIONS: Pneumoperitoneum is a common finding after POEM and is not indicative of unfavorable patient outcome. Conversely, post POEM pleural effusion and extraesophageal contrast leakage are associated with a longer hospital stay. KEY POINTS: • Water-soluble esophagogram is a valid diagnostic modality to diagnose early complications after esophageal endoscopic myotomy for esophageal motility disorders. • At multivariate analysis, pleural effusion and extraesophageal contrast leakage are associated with a prolonged hospital stay after peroral endoscopic myotomy. • Pneumoperitoneum is not associated with unfavorable outcome after peroral endoscopic myotomy.