Pelvic Floor Levator Hiatus Measurements

Abstract

We found that the MRI measurements obtained from the sagittal images were consistently greater than the corresponding US images. In contrast, there was not the same consistency of difference between MRI and US for the axial images. This suggests possible variation in acquisition planes for axial images or interpretation of landmarks for the sagittal images.

Comparison of translabial three-dimensional ultrasound with magnetic resonance imaging for measurement of levator hiatal biometry at rest

“…In the present study, measurements obtained on MRI were systematically and statistically significantly larger than those on translabial 3D ultrasound, as shown by the Bland–Altman plots (Figure ), in which the mean difference was below zero for all three measurements. This is in contrast to the findings of Nardos et al . In the latter study, levator hiatus measurements obtained by translabial 3D ultrasound and by MRI were compared in 37 asymptomatic nulliparous women.…”

“…The anteroposterior diameter was measured in the sagittal plane, while the levator hiatal area, the anteroposterior diameter and the transverse diameter were measured in the axial plane. The authors found that only the mean anteroposterior diameter in the sagittal plane was significantly larger on MRI than on ultrasound, while in the axial plane the hiatal area, anteroposterior diameter and transverse diameter were larger on ultrasound than on MRI. This difference between ultrasound and MRI measurements was explained by the fact that, on ultrasound, axial rendered volumes of a slice 2 cm thick were used compared to one axial plane on MRI.…”

“…Majida et al found very good agreement between translabial 3D ultrasound and MRI for the measurement of levator hiatal biometry. Nardos et al found no difference between ultrasound and MRI for imaging in the axial plane. However, in the study by Kruger et al , measurements obtained on MRI were significantly larger than those on translabial 3D ultrasound.…”

“…To enable comparisons of studies using ultrasound with studies using MRI, it is necessary to determine whether levator hiatal biometry is the same on both imaging modalities. Three studies have compared translabial 3D ultrasound with MRI, all of which used healthy nulliparous volunteers. Majida et al found very good agreement between translabial 3D ultrasound and MRI for the measurement of levator hiatal biometry.…”

Vaginal hyperlaxity syndrome: a new concept and challenge

“…In addition to the connective tissue hiatus, there is a dynamic hiatus of skeletal levator ani muscles, the muscles which are contracted during a Kegel exercise. The size of this muscle hiatus can be measured by MRI, ultrasound [13], and by digital exam [14].…”