Influence of diffusion weighted imaging and contrast enhanced T1 sequences on the diagnostic accuracy of magnetic resonance enterography for Crohn's disease.

OBJECTIVES: To evaluate the additional diagnostic benefit of diffusion weighted imaging (DWI) and contrast enhanced (CE) images during MR enterography (MRE) of Crohn's disease. METHODS: Datasets from 73 patients (mean age 32; 40 male) (28 new-diagnosis, 45 relapsed) were read independently by two radiologists selected from a pool of 13. Radiologists interpreted datasets using three sequential sequence blocks: (1) T2 weighted and steady state free precession gradient echo (SSFP) images alone (T2^); (2) T2 weighted and SSFP images with DWI (T2 + DWI^) and; (3) T2 weighted images, SSFP, DWI and post-contrast enhanced (CE) T1 images (T2 + DWI + CE^), documenting presence, location, and activity of small bowel disease. For each sequence block, sensitivity and specificity (readers combined) was calculated against an outcome-based construct reference standard. RESULTS: 59/73 patients had small bowel disease. Per-patient sensitivity for disease detection was essentially identical (80 % [95 % CI 72, 86], 81 % [73,87], and 79 % [71,86] for T2^, T2 + DWI^and T2 + DWI + CE^respectively). Specificity was identical (82 % [64 to 92]). Per patient sensitivity for disease extent was 56 % (47,65), 56 % (47,65) and 52 % (43 to 61) respectively, and specificity was 82 % (64 to 92) for all blocks. Sensitivity for active disease was 97 % (90,99), 97 % (90,99) and 98 % (92,99), and specificity was also comparable between all sequence combination reads. Results were consistent across segments and newly diagnosed/relapse patients. CONCLUSION: There is no additional diagnostic benefit of adding either DWI or CE to T2 FSE and SSFP sequences for evaluating small bowel Crohn's disease, suggesting MRE protocols can be simplified safely.

Interobserver variation in the interpretation of magnetic resonance enterography in Crohn's disease.

OBJECTIVES: To evaluate interobserver variability for diagnosis of disease presence and extent of small bowel and colonic Crohn's disease using MR enterography (MRE). METHODS: Data from the first 73 consecutive patients (mean age 32, 33F, 28 new diagnosis, 45 suspected relapse) recruited to a multicentre, prospective diagnostic accuracy trial evaluating MRE for small bowel Crohn's disease were each read independently by three (from a pool of 20) radiologists. Radiologists documented presence and segmental location of small bowel Crohn's disease and recorded morphological mural/extramural parameters for involved segments. Per patient percentage agreement for disease presence and extent were calculated against an outcome-based construct reference standard (averaged between pairs of readers). Prevalence-adjusted bias-adjusted κ (PABAK) was calculated. RESULTS: Agreement for small bowel disease presence for new diagnosis/relapsed patients was 68%(κ = 0.36)/ 78% (κ = 0.56) and 43%(κ = 0.14)/ 53% for disease extent (κ = 0.07), respectively. For disease presence, all three radiologists agreed correctly with the reference standard in 41/59 (69%) of patients with small bowel involvement, and in 8/14 (57%) cases of without small bowel disease. Agreement was highest for multisegment disease, greater than 5 cm in length, with mural thickness>6 mm, and increased mural T2 signal. Agreement for colonic disease presence was 61% (κ = 0.21 fair agreement) for new diagnosis/ 60% (κ = 0.20, slight agreement) for relapsed patients. CONCLUSION: There is a reasonable agreement between radiologists for small bowel disease presence using MRE for newly diagnosed Crohn's disease, and patients with suspected relapse, respectively. Agreement is lower for disease extent. ADVANCES IN KNOWLEDGE: There is reasonable agreement between radiologists for small bowel disease presence using MRE for newly diagnosed (68%) Crohn's disease, and patients with suspected relapse (78%). Agreement is lower for disease extent (43% new diagnosis and 53% suspected relapse).

A real-world study evaluating ultrasound-guided percutaneous non-targeted liver biopsy needle failures and pathology sample-quality assessment in both end-cut and side-notch needles.

OBJECTIVES: To determine biopsy device failures, causative factors, complications and sample quality of the 16G end-cut Biopince™ and side-notch Bard™ needles. METHODS: All ultrasound-guided non-targeted liver biopsies between 01/01/2016 and 31/12/2018 were included. Operator, device, number of failures, complications and repeat biopsies were recorded. Histopathology samples were reviewed for all cases of needle failure and a group with no failures, and graded "yes/no" for the presence of steatosis, inflammation and fibrosis. The pathology slides from these cases were reviewed to assess biopsy sample quality (length and portal tract number). The failure and no-failure groups were compared in terms of device type/histology, and sample quality was compared between the needle types. RESULTS: 1004 patients were included. 93.8% (n = 942) required one needle pass to obtain a sample and 6.2% (n = 62) required >1 pass due to needle failure. Total of 76 needle failures, more with end-cut than side-notch needles (8.7% vs 2.9%) (p < 0.001). No needle failures resulted in complication. The presence of liver fibrosis was associated with fewer needle failures (p = 0.036). The major complication rate was 0.4% (4/1044). A biopsy with >10 portal tracts was obtained in 90.2% of specimens > 20 mm long, compared with 66% of 16-20 mm biopsies and 21% of <16 mm biopsies. The target of >10 portal tracts was achieved in 10/26 (38.5%) of side-notch biopsies and 64/90 (71.1%) of end-cut biopsies (p = 0.004). CONCLUSION: Ultrasound-guided liver biopsy is safe and sample quality is consistently good when a core >20 mm long is obtained. The end-cut biopsy device generated reliably good quality biopsy samples; however, the needle failure rate was significantly higher than the side-cut needle. ADVANCES IN KNOWLEDGE: Ultrasound-guided liver biopsy specimen quality is consistently good when a core >20 mm long is obtained which can be achieved with a single pass using the 16G BiopinceTM end-cut needle, although the needle failure rate is significantly higher than the 16G Max-Core™ Bard™ side-notch needle.

Influence of computer-aided detection false-positives on reader performance and diagnostic confidence for CT colonography.

OBJECTIVE: The objective of our study was to investigate whether an increasing number of computer-aided detection (CAD) false-positives decreases reader sensitivity, specificity, and confidence for nonexpert readers of CT colonography (CTC). MATERIALS AND METHODS: Fifty CTC data sets (29 men; mean age, 65 years), 25 of which contained 35 polyps > or = 5 mm, were selected in which CAD had 100% polyp sensitivity at two sphericity settings (0 and 75) but differed in the number of false-positives. The data sets were read by five readers twice: once at each sphericity setting. Sensitivity, specificity, report time, and confidence before and after second-read CAD were compared using the paired exact and Student's t test, respectively. Receiver operating characteristic (ROC) curves were generated using reader confidence (1-100) in correct case classification (normal or abnormal). RESULTS: CAD generated a mean of 42 (range, 3-118) and 15 (range, 1-36) false-positives at a sphericity of 0 and 75, respectively. CAD at both settings increased per-patient sensitivity from 82% to 87% (p = 0.03) and per-polyp sensitivity by 8% and 10% for a sphericity of 0 and 75, respectively (p < 0.001). Specificity decreased from 84% to 79% (sphericity 0 and 75, p = 0.03 and 0.07). There was no difference in sensitivity, specificity, or reader confidence between sphericity settings (p = 1.0, 1.0, 0.11, respectively). The area under the ROC curve was 0.78 (95% CI, 0.70-0.86) and 0.77 (0.68-0.85) for a sphericity of 0 and 75, respectively. CAD added a median of 4.4 minutes (interquartile range [IQR], 2.7-6.5 minutes) and 2.2 minutes (IQR, 1.2-4.0 minutes) for a sphericity of 0 and 75, respectively (p < 0.001). CONCLUSION. CAD has the potential to increase the sensitivity of readers inexperienced with CTC, although specificity may be reduced. An increased number of CAD-generated false-positives does not negate any beneficial effect but does reduce efficiency.