Evaluation of established and new reference lines for the standardization of transperineal ultrasound.
OBJECTIVE
To examine the performance of a new reference line for the assessment of pelvic organ descent by transperineal ultrasound.


METHODS
We compared our newly proposed reference line, between two hyperechoic contours of the symphysis pubis (Line 3), with the horizontal reference line proposed by Dietz and Wilson (Line 1) and the central pubic line proposed by Schaer et al. (Line 2). Ultrasound volumes of 94 women obtained in routine clinical practice were analyzed. The perpendicular distance from the reference lines to the internal sphincter and the most dependent part of the bladder base was measured for volumes obtained at rest, on pelvic floor muscle contraction, on Valsalva maneuver and during coughing. Measurements were repeated 4 months later by the same examiner. Rates of assessment were calculated, and intrarater reliability was evaluated using Bland-Altman plots and intraclass correlation coefficients.


RESULTS
Line 2 had to be excluded from reliability analysis because of an assessment rate of only 12%, whereas Lines 1 and 3 could be assessed in 100% of volumes. The intrarater repeatability of Lines 1 and 3 was shown to be very similar.


CONCLUSIONS
In this comparison of three potential reference lines for the assessment of pelvic organ descent by transperineal ultrasound, the central pubic line was shown to be inferior owing to poor visibility in our volumes. Inter-rater reliability analysis and validation studies are required to confirm our results.
Department of Gynaecology and Obstetrics, University Hospital Aachen, Aachen, Germany.
J
J
Hennemann
L N
LN
Kennes
N
N
Maass
L
L
Najjari
D005260:Female; D006801:Humans; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D015588:Observer Variation; D009929:Organ Size; D017773:Pelvic Floor / Q000000981:diagnostic imaging / Q000502:physiology; D056887:Pelvic Organ Prolapse / Q000000981:diagnostic imaging*; D010502:Perineum / Q000000981:diagnostic imaging; D011631:Pubic Symphysis / Q000000981:diagnostic imaging; D012015:Reference Standards; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging; D014636:Valsalva Maneuver
perineal ultrasound; prolapse; reference line; stress urinary incontinence; symphysis pubis