Colorectal intussusception due to adenocarcinoma presenting as acute bowel obstruction in an adult.

Colorectal intussusception is a rare entity in adults presenting an acute abdomen. The authors present a case of a 73-year-old female who presented with an acute large bowel obstruction. Abdominal computed tomography (CT) scan reveals a colorectal intussusception with a colonic distension upstream. Laparoscopy founds out a stenotic tumor on colorectal junction corresponding with an adenocarcinoma on histopathological exam. CT scan is the most specific diagnostic test for intussusception and is superior to ultrasonography and endoscopy and thus should be performed preferentially.

Added-value of advanced magnetic resonance imaging to conventional morphologic analysis for the differentiation between benign and malignant non-fatty soft-tissue tumors.

OBJECTIVES: To evaluate the added value of DWI, qualitative proton MR spectroscopy (H-MRS) and dynamic contrast-enhanced perfusion (DCE-P) to conventional MRI in differentiating benign and malignant non-fatty soft tissue tumors (NFSTT). METHODS: From November 2009 to August 2017, 288 patients with NFSTT that underwent conventional and advanced MRI were prospectively evaluated. The study was approved by the local ethics committee. All patients signed an informed consent. A musculoskeletal (R1) and a general (R2) radiologist classified all tumors as benign, malignant, or indeterminate according to morphologic MRI features. Then, DWI, H-MRS, and DCE-P data of indeterminate tumors were analyzed by two additional radiologists (R3 and R4). Advanced techniques were considered individually and in combination for tumor benign-malignant differentiation using histology as the gold standard. RESULTS: There were 104 (36.1%) malignant and 184 (63.9%) benign tumors. Conventional MRI analysis classified 99 tumors for R1 and 135 for R2 as benign or malignant, an accuracy for the identification of malignancy of 87.9% for R1 and 83.7% for R2, respectively. There were 189 indeterminate tumors for R1. For these tumors, the combination of DWI and H-MRS yielded the best accuracy for malignancy identification (77.4%). DWI alone provided the best sensitivity (91.8%) while the combination of DCE-P, DWI, and H-MRS yielded the best specificity (100%). The reproducibility of the advanced imaging parameters was considered good to excellent (Kappa and ICC > 0.86). An advanced MRI evidence-based evaluation algorithm was proposed allowing to characterize 28.1 to 30.1% of indeterminate non-myxoid tumors. CONCLUSION: The prioritized use of advanced MRI techniques allowed to decrease by about 30% the number of non-myxoid NFSTT deemed indeterminate after conventional MRI analysis alone. KEY POINTS: • When morphological characterization of non-fatty soft tissue tumors is possible, the diagnostic performance is high and there is no need for advanced imaging techniques. • Following morphologic analysis, advanced MRI techniques reduced by about 30% the number of non-myxoid indeterminate tumors. • DWI is the keystone of advanced imaging techniques yielding the best sensitivity (91.8%). Optimal specificity (> 90%) is obtained by a combination of advanced techniques.

Alternative PACS interface devices are well-accepted and may reduce radiologist's musculoskeletal discomfort as compared to keyboard-mouse-recording device.

OBJECTIVE: To evaluate the use of two alternative picture archiving and communication systems (PACS) interface devices (a graphics tablet and a handheld controller) in clinical practice and on task-oriented exercises. MATERIAL AND METHODS: Eleven senior radiologists were prospectively evaluated. The participants used the two tested interface devices for 10 working periods each and answered a questionnaire to evaluate the ergonomics of this experience. The prevalence of work-related musculoskeletal discomfort with the standard PACS interface set (mouse-keyboard-recording device) and these two devices was assessed. Exercises evaluating image scrolling and selection, image zooming and panning, image windowing, performing measurements, and reporting were performed with the standard PACS interface set and with the two tested devices. The sitting posture and hand position were evaluated. RESULTS: The general appreciation of the two alternative interface devices was considered to be similar to that of the standard interface set. The ergonomics of the handheld controller was considered to be slightly better than that of the standard interface set. The prevalence of musculoskeletal discomfort was 81%, 45%, and 18% for the standard interface set, graphics tablet, and handheld controller, respectively. With the graphics tablet and the handheld controller in 45% and 60%, respectively, there was a working posture change with respect to the standard interface set. The mean total exercise completion times of both tested devices were 27% higher than that of the standard interface set. CONCLUSION: Despite the increase in completion time of the task-oriented exercises, the tested devices were well accepted and considered to be more comfortable than the standard set. KEY POINTS: • Alternative PACS interface devices can be used as a substitute for the standard mouse-keyboard-recording device set with a potential improvement in work ergonomics and a reduction in work-related musculoskeletal discomfort.

MRI for prostate cancer: can computed high b-value DWI replace native acquisitions?

OBJECTIVE: To compare computed high b-value diffusion-weighted images (c-DWI) derived from low b-value DWI images and acquired high b-value DWI (a-DWI), in overall image quality and prostate cancer detection rate. MATERIALS AND METHODS: A total of 124 consecutive men with suspected prostate cancer (PCa) underwent diagnosis prostate MRI on a 3.0 T MR system using a 32-channel phased-array torso coil. Among them, 63 underwent prostate biopsy. MRI protocol included 3DT2w images, high resolution Fov Optimized and Constrained Undistorted Single-Shot (FOCUS™) DWI images with b-values of 100, 400, 800, and 2000 s/mm2 and dynamic contrast enhanced images. C-DWI images (2000 and 2500 s/mm2) were derived from the three lower acquired b-value DWI images using a mono-exponential diffusion decay. C-DWI and acquired high b-value DWI (a-DWI) (2000 s/mm2) were compared for image quality (background signal suppression, anatomic clarity, ghosting, distortion) and tumor conspicuity by four radiologists. RESULTS: C-DWIs demonstrated higher rating than a-DWIs for overall image quality despite worsened ghosting. In patients with a biopsy, similar detection rate was observed while conspicuity was better with c-DWI (p < 0.001). Non-acquisition of high b-value a-DWI reduced total acquisition time by 220 s per patient. CONCLUSION: C-DWI provides a substantial reduction in acquisition time while maintaining comparable prostate cancer detection rate and improving global image quality. KEY POINTS: • Computed DWI improves global quality of prostate MRI. • Computed DWI improves analysis of DWI images with decrease acquisition time. • Computed DWI provides greater background suppression of parenchyma and improves conspicuity of suspicious lesion.