Bengt Norén

Increase of serum C-reactive protein is an early indicator of subsequent symptomatic anastomotic leakage after anterior resection.

Objective  This prospective study investigated the factors which might indicate anastomotic leakage after low anterior resection.

Consistent intensity inhomogeneity correction in water–fat MRI

To quantitatively and qualitatively evaluate the water‐signal performance of the consistent intensity inhomogeneity correction (CIIC) method to correct for intensity inhomogeneities

Plain X-Ray Films and Air Enema Films Reflect Severe Mucosal Inflammation in Acute Ulcerative Colitis

In a prospective study of 34 patients with active ulcerative colitis, the findings of inflammation on plain abdominal films and air enema films were compared to those at colonoscopy including biopsy within 10 days. The degree of inflammation on X-ray films was graded independently by two radiologists, at colonoscopy by one gastroenterologist and from histological slides from 6 different colon segments by one pathologist for each patient. Air enema films had a high sensitivity for endoscopically confirmed friable or ulcerated mucosa (0.91). There was a high specificity (0.86) when excluding inflammation in individual colon segments. Absence of fecal residue as an indication of active inflammation had the same positive predictive value, 0.95, as an abnormal air enema film, 0.98 for endoscopically confirmed inflamed mucosa. The presence of fecal residue or a normal air enema film excluded a friable or ulcerated mucosa at endoscopy with negative predictive values of 0.83 and 0.86, respectively. Patients who had had a complete colonoscopy (n = 16) were divided into groups with total, extensive or distal colitis. Air enema films underestimated the extent of inflammation in 8 of 16 patients compared to colonoscopy. Of 6 patients with distal disease only on air enema films, 5 had disease above the splenic flexure at endoscopy. In patients with ulcerative colitis (1) the presence of fecal residue and a normal air enema film exclude a friable or ulcerated mucosa with a high degree of certainty, and (2) the absence of fecal residue and an abnormal air enema film are predictors of the presence of endoscopically confirmed inflammation.

Subjective evaluation of user experience in interactive 3D visualization in a medical context

New display technologies enable the usage of 3D-visualization in a medical context. Even though user performance seems to be enhanced with respect to 2D thanks to the addition of recreated depth cues, human factors, and more particularly visual comfort and visual fatigue can still be a bridle to the widespread use of these systems. This study aimed at evaluating and comparing two different 3D visualization systems (a market stereoscopic display, and a state-of-the-art multi-view display) in terms of quality of experience (QoE), in the context of interactive medical visualization. An adapted methodology was designed in order to subjectively evaluate the experience of users. 14 medical doctors and 15 medical students took part in the experiment. After solving different tasks using the 3D reconstruction of a phantom object, they were asked to judge their quality of the experience, according to specific features. They were also asked to give their opinion about the influence of 3D-systems on their work conditions. Results suggest that medical doctors are opened to 3D-visualization techniques and are confident concerning their beneficial influence on their work. However, visual comfort and visual fatigue are still an issue of 3D-displays. Results obtained with the multi-view display suggest that the use of continuous horizontal parallax might be the future response to these current limitations.

Computed Tomographic Colonography: Comparison of Two Workstations

Purpose: To compare two commercially available computed tomography (CT) colonography systems with respect to interobserver variability, the influence of level of expertise, and the gradual reduction of reviewing time for each system. Material and Methods: Two residents and two radiologists using Siemens CTAPP Colography software and Viatronix V3D-Colon software reviewed supine and prone CT acquisitions from 24 patients in a primary 3D endoluminal view. The observers graded each case with respect to technical quality and diagnostic value, assessed the presence of pathology, and indicated the time spent on the viewing. Results: Significant differences were found in technical quality (P<0.001) and diagnostic value (P<0.001) depending on which system was used, with higher scores for the Viatronix software. The agreement between specialists tended to be higher than that between residents (κ = 0.63 (0.30–0.95) vs. κ = 0.51 (0.21–0.81)), and the residents gave significantly (P<0.001) higher scores of technical quality. However, the level of expertise had no significant impact on the assessments. We noted extensive variability in pathological lesions found by the different observers. The number of findings did not differ between workstations, but the viewers tended to report larger polyp sizes with the Viatronix software. The time needed for viewing decreased significantly from the first to the last examination viewed by each observer. Conclusion: Both the evaluated systems present trustworthy images of the human colon, but in a primary 3D setting the Viatronix software is favored owing to the user-friendly interface, higher experienced technical quality, and better diagnostic value.

Comparing hepatic 2D and 3D magnetic resonance elastography methods in a clinical setting – Initial experiences

Purpose Continuous monitoring of liver fibrosis progression in patients is not feasible with the current diagnostic golden standard (needle biopsy). Recently, magnetic resonance elastography (MRE) has emerged as a promising method for such continuous monitoring. Since there are different MRE methods that could be used in a clinical setting there is a need to investigate whether measurements produced by these MRE methods are comparable. Hence, the purpose of this pilot study was to evaluate whether the measurements of the viscoelastic properties produced by 2D (stiffness) and 3D (elasticity and ‘Gabs,Elastic’) MRE are comparable. Materials and methods Seven patients with diffuse or suspect diffuse liver disease were examined in the same day with the two MRE methods. 2D MRE was performed using an acoustic passive transducer, with a 1.5 T GE 450 W MR system. 3D MRE was performed using an electromagnetic active transducer, with a 1.5 T Philips Achieva MR system. Finally, mean viscoelastic values were extracted from the same anatomical region for both methods by an experienced radiologist. Results Stiffness correlated well with the elasticity, R2 = 0.96 (P < 0.001; slope = 1.08, intercept = 0.61 kPa), as well as with ‘Gabs,Elastic’ R2 = 0.96 (P < 0.001; slope = 0.95, intercept = 0.28 kPa). Conclusion This pilot study shows that different MRE methods can produce comparable measurements of the viscoelastic properties of the liver. The existence of such comparable measurements is important, both from a clinical as well as a research perspective, since it allows for equipment-independent monitoring of disease progression.

Visual assessment of biliary excretion of Gd-EOB-DTPA in patients with suspected diffuse liver disease – A biopsy-verified prospective study

Highlights • MR using hepatocyte specific contrast may potentially assess liver function.• Covariance between contrast uptake and histo-pathological scoring of liver fibrosis.• No relationship between visually assessed biliary contrast excretion and fibrosis scoring.• No relationship between visually assessed biliary excretion and contrast uptake parameters.

Book Review : Atlas of cross-sectional and projective MR cholangiopancreatography; L van Hoe, D Vanbeckevoort and W Van Seenbergen.

Book Review : Atlas of cross-sectional and projective MR cholangiopancreatography; L van Hoe, D Vanbeckevoort and W Van Seenbergen.