For patients undergoing MRgFUS, prediction models and multivariate analyses have found that nonperfused volume, a surrogate of symptom improvement, is a function of fibroid signal intensity, peak and time to peak enhancement, subcutaneous fat thickness, and distance from spine. A nonperfused volume >80% predicted clinical success in more than 80% of patients [73-76]. US Pelvis Transabdominal A combination of TAUS and TVUS of the pelvis is a frequently used imaging modality in pretreatment evaluation of known uterine fibroids [77,78]. TAUS is often useful in significantly enlarged fibroid uterus or large subserosal/pedunculated fibroids that may render poor visualization on TVUS because of limited field-of-view from poor acoustic penetration. A limitation of TAUS is a poor acoustic window from decompressed urinary bladder, retroverted uterus, large body habitus, and bowel gas [46]. US Pelvis Transvaginal TVUS provides higher contrast and spatial resolution and should be combined with the TAUS whenever possible to evaluate suspected uterine fibroid [46,47]. TVUS has a reported sensitivity of 90% to 99% for detecting uterine fibroids and a sensitivity of 90% and specificity of 98% for the diagnosis of submucosal fibroids [43,48,49]. The limitations of TVUS are a limited depth of penetration and a shallow focal length that can limit the evaluation of large or subserosal/pedunculated fibroids. The presence of numerous fibroids may also pose challenge in clearly delineating and precisely measuring the fibroids because of too poor an acoustic window. US Duplex Doppler Pelvis Although Doppler imaging is labeled under separate imaging procedure per ACR methodology, this document considers it to be a standard component of pelvic US. Color and spectral Doppler are routinely used in pelvic US examinations to evaluate internal vascularity of pelvic/uterine findings and to differentiate between vascular and nonvascular tissue [47].
Fibroids. For patients undergoing MRgFUS, prediction models and multivariate analyses have found that nonperfused volume, a surrogate of symptom improvement, is a function of fibroid signal intensity, peak and time to peak enhancement, subcutaneous fat thickness, and distance from spine. A nonperfused volume >80% predicted clinical success in more than 80% of patients [73-76]. US Pelvis Transabdominal A combination of TAUS and TVUS of the pelvis is a frequently used imaging modality in pretreatment evaluation of known uterine fibroids [77,78]. TAUS is often useful in significantly enlarged fibroid uterus or large subserosal/pedunculated fibroids that may render poor visualization on TVUS because of limited field-of-view from poor acoustic penetration. A limitation of TAUS is a poor acoustic window from decompressed urinary bladder, retroverted uterus, large body habitus, and bowel gas [46]. US Pelvis Transvaginal TVUS provides higher contrast and spatial resolution and should be combined with the TAUS whenever possible to evaluate suspected uterine fibroid [46,47]. TVUS has a reported sensitivity of 90% to 99% for detecting uterine fibroids and a sensitivity of 90% and specificity of 98% for the diagnosis of submucosal fibroids [43,48,49]. The limitations of TVUS are a limited depth of penetration and a shallow focal length that can limit the evaluation of large or subserosal/pedunculated fibroids. The presence of numerous fibroids may also pose challenge in clearly delineating and precisely measuring the fibroids because of too poor an acoustic window. US Duplex Doppler Pelvis Although Doppler imaging is labeled under separate imaging procedure per ACR methodology, this document considers it to be a standard component of pelvic US. Color and spectral Doppler are routinely used in pelvic US examinations to evaluate internal vascularity of pelvic/uterine findings and to differentiate between vascular and nonvascular tissue [47].