Measurement of uterine fibroid volume: a comparative accuracy and validation of methods study.

OBJECTIVE: A range of measurement techniques have been described which may be used to calculate uterine fibroid volume. A commonly-reported method involves application of a formula for the volume of an ellipsoid sphere to three orthogonal axes of a fibroid as measured on cross-sectional images. We aimed to compare this method and a second method, that of software-computed parallel planimetric uterine fibroid computation on MRI images, to a gold standard: the volume of objects measured by water displacement. We also compared these methods in volume estimation of patient fibroids using MRI data. STUDY DESIGN: Mixed observational study and blinded cross-sectional analysis of imaging data. RESULTS: Large inter-observer variability was noted when using the ellipsoid formula method, which was also inaccurate when compared to the gold standard. Conversely, the parallel planimetric method showed excellent interobserver correlation and a high degree of correlation with gold standard volume measurements. CONCLUSION: We conclude that the parallel planimetric method, although a more complex and time consuming technique, is the more accurate and therefore preferred method for measuring uterine fibroid volume.

Diagnostic precision of endoanal MRI in the detection of anal sphincter pathology: a meta-analysis.

OBJECTIVE: This study aims to evaluate the diagnostic precision of endoanal magnetic resonance imaging in identifying anal sphincter injury and/or atrophy when compared with either endoanal ultrasound or surgical diagnosis. MATERIALS AND METHODS: Quantitative meta-analysis was performed on nine studies, comparing endoanal MRI with endoanal ultrasound or surgical diagnosis in 157 patients. Sensitivity, specificity, and diagnostic odds ratio were calculated for each study. Summary receiver operating characteristic curves (SROC) and subgroup analysis were undertaken. RESULTS: The overall sensitivity and specificity of endoanal MRI for external sphincter injury was 0.78 (95%CI: 0.66-0.84) and 0.66 (95%CI: 0.51-0.79), respectively. For internal sphincter injury detection, this was 0.63 (95%CI: 0.50-0.74) and 0.71 (95%CI: 0.60-0.81), respectively. For detection of atrophy, this was 0.86 (95%CI: 0.71-0.95) and 0.82 (95%CI: 0.65-0.93), respectively. The area under the SROC curve and diagnostic odds ratio were 0.84 (SE = 0.07) and 6.14 (95%CI: 2.17-17.4) for external sphincter injury, 0.79 (SE = 0.07) and 4.60 (95%CI: 1.75-12.15) for internal sphincter injury, and 0.92 (SE = 0.08) and 21.49 (95%CI: 2.87-160.64) for sphincter atrophy. CONCLUSION: Endoanal MRI was sensitive and specific for the detection of external sphincter injury and especially sphincter atrophy. It may be useful as an alternative to endoanal ultrasound in patients presenting with fecal incontinence, although further clinical studies are needed to identify its best application in clinical practice.