Bowel preparation in MRI for detection of endometriosis: Comparison of the effect of an enema, no additional medication and intravenous butylscopolamine on image quality.

PURPOSE: To compare the effect of three different patient preparation strategies for reducing bowel motion on image quality in pelvic MRI. METHODS: Retrospective study in which 95 consecutive patients undergoing pelvic MRI were subdivided based on preparation type for reduction of bowel motion: group 1 (N = 31) fasted 4 h and applied an enema (Bisacodyl 10 mg); group 2 (N = 32) received no medication; group 3 (N = 32) received intravenous butylscopolamine (Buscopan® 50 mg). Image quality was reviewed by visual assessment of delineation (3-point-scale) of pelvic structures: uterus, adnexa, bladder, rectum, sigmoid, uterosacral ligaments, round ligaments and small bowel. As secondary endpoint the presence of rectal wall edema was evaluated. Interobserver agreement was calculated, as well as relative diagnostic odds ratios (RDOR) for the protocols to provide an outcome in the best delineation category. RESULTS: Interobserver agreement proportions varied from 0.48 to 1.00. The rectum and sigmoid colon respectively have a 5.4 and 2.6 RDOR when butylscopolamine is applied compared to Bisacodyl (P = 0.051; P = 0.008), and a 4.2 and 5.7 times higher RDOR with Bisacodyl preparation compared to no medical preparation (P = 0.006; P < 0.01). Small bowel delineation was significantly better with butylscopolamine compared to Bisacodyl (P = 0.007). There was no significant difference in delineation of the other structures between protocols. There is a significant higher chance of observing rectal wall edema with Bisacodyl compared to the other protocols (both P < 0.001). CONCLUSIONS: Butylscopolamine provides better delineation of the small bowel and rectosigmoid compared to Bisacodyl, which in turn, provides better delineation of the rectosigmoid compared to no medication. Moreover, Bisacodyl causes rectal wall edema in the majority of cases.

Response to Letter: Intrapatient Comparison of the Hepatobiliary Phase of Gd-BOPTA and Gd-EOB-DTPA in the Differentiation of HCA From FNH.

LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3 J. Magn. Reson. Imaging 2020;52:1281-1282.

Intrapatient Comparison of the Hepatobiliary Phase of Gd-BOPTA and Gd-EOB-DTPA in the Differentiation of Hepatocellular Adenoma From Focal Nodular Hyperplasia.

BACKGROUND: Current imaging guidelines do not specify the preferred hepatobiliary contrast agent when differentiating hepatocellular adenoma (HCA) from focal nodular hyperplasia (FNH) on MRI. PURPOSE: To analyze intrapatient differences in the hepatobiliary phase (HBP) after use of both gadobenate dimeglumine (Gd-BOPTA) and gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI to differentiate HCA from FNH. STUDY TYPE: Retrospective. POPULATION: Patients who underwent both Gd-BOPTA and Gd-EOB-DTPA-enhanced MRI, including 33 patients with 82 lesions (67 HCA; 15 FNH), with a step-down reference standard of pathology, 20% regression, identical appearance to earlier biopsied lesions, and stringent imaging findings. FIELD STRENGTH/SEQUENCE: 1.5T and 3T HBP of Gd-BOPTA and Gd-EOB-DTPA-enhanced MRI, precontrast fat-suppressed T1 -weighted sequence. ASSESSMENT: Signal intensities relative to the surrounding liver in the HBP were assessed by two observers. STATISTICAL TESTS: Sensitivity and specificity of HCA diagnosis were calculated for both contrast agents. Interobserver agreement was evaluated using Cohen's kappa; differences in degree of certainty for scoring a lesion were calculated by means of the Wilcoxon signed rank test. Differences in signal intensity between Gd-BOPTA and Gd-EOB-DTPA were calculated using McNemar's test. RESULTS: Almost perfect agreement was found between observers for scored signal intensities with both contrast agents. In 30 of the 82 lesions (37%) a difference was observed between contrast agents in the HBP, with Gd-EOB-DTPA proving correct in all but one of the discordant lesions. When distinguishing HCA from FNH, Gd-BOPTA showed a sensitivity of 46% (31/67) and a specificity of 87% (13/15), while the sensitivity and specificity of Gd-EOB-DTPA was 85% (57/67) and 100% (15/15), respectively. A risk of misclassifying HCA as FNH typically occurs for Gd-BOPTA when lesions are intrinsically hyperintense (P < 0.005). DATA CONCLUSION: The HBP of Gd-EOB-DTPA shows superior accuracy in ruling out HCA in comparison with Gd-BOPTA, especially when the lesion is intrinsically hyperintense on T1 -weighted imaging. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:700-710.

[An infant with a bowed lower leg]. / Een zuigeling met een gebogen onderbeen.

The parents of a 5-month-old boy noticed bowing of his left leg. Radiographic survey showed an anterolateral bowing of the left tibia and fibula with intramedullary sclerosis, typical for neurofibromatosis type 1. As the mother had neurofibromatosis, this boy was diagnosed with neurofibromatosis type 1.