Learning process for performing and analyzing 3D/4D transperineal ultrasound imaging and interobserver reliability study.

OBJECTIVES: To evaluate the learning process for acquiring three- and four-dimensional (3D/4D) transperineal ultrasound volumes of the levator hiatus (LH) dimensions at rest, during pelvic floor muscle (PFM) contraction and on Valsalva maneuver, and for analyzing the ultrasound volumes, as well as to perform an interobserver reliability study between two independent ultrasound examiners. METHODS: This was a prospective study including 22 women. We monitored the learning process of an inexperienced examiner (IE) performing 3D/4D transperineal ultrasonography and analyzing the volumes. The examination included acquiring volumes during three PFM contractions and three Valsalva maneuvers. LH dimensions were determined in the axial plane. The learning process was documented by estimating agreement between the IE and an experienced examiner (E) using the intraclass correlation coefficient. Agreement was calculated in blocks of 10 ultrasound examinations and analyzed volumes. After the learning process was complete the interobserver reliability for the technique was calculated between these two independent examiners. RESULTS: For offline analysis of the first 10 ultrasound volumes obtained by E, good to very good agreement between E and IE was achieved for all LH measurements except for the left and right levator-urethra gap and pubic arc. For the next 10 analyzed volumes, agreement improved for all LH measurements. Volumes that had been obtained by IE and E were then re-evaluated by IE, and good to very good agreement was found for all LH measurements indicating consistency in volume acquisition. The interobserver reliability study showed excellent ICC values (ICC, 0.81-0.97) for all LH measurements except the pubic arc (ICC = 0.67). CONCLUSION: 3D/4D transperineal ultrasound is a reliable technique that can be learned in a short period of time.

Validation of three-dimensional perineal ultrasound and magnetic resonance imaging measurements of the pubovisceral muscle at rest.

OBJECTIVE: To compare biometric measurements of the pubovisceral muscle during rest, measured using transperineal three-dimensional (3D) ultrasound and magnetic resonance imaging (MRI). METHODS: In this prospective study, 18 female volunteers underwent 3D perineal ultrasound examination and MRI. All women were examined at rest in the supine position and the following measurements were taken: area and anteroposterior and transverse diameters of the levator hiatus; thickness of the pubovisceral muscle, measured lateral to the vagina and to the rectum, on the right and left sides; length of the levator-urethra gap (LUG), measured from the center of the urethra to the insertion of the pubovisceral muscle on the pubic bone. Interclass correlation coefficients (ICC) between the measurements obtained with 3D ultrasound and with MRI were calculated. To quantify the intermeasurement agreement, the bias and SDs were calculated, and limits of agreement constructed. One investigator performed all the analyses. RESULTS: There was no significant difference between the mean values of the measurements by 3D perineal ultrasound and those by MRI. The ICC values showed very good agreement (range, 0.80-0.97). There was a significant positive bias for LUG on the left side and muscle thickness on the right side of the vagina. CONCLUSION: These results suggest that 3D ultrasound could be used instead of MRI when evaluating static pelvic floor anatomy in women without pelvic organ prolapse at rest.

Pelvic floor function is independently associated with pelvic organ prolapse.

OBJECTIVE: To investigate the risk factors for pelvic organ prolapse (POP), including physical activity, clinically measured joint mobility and pelvic floor muscle (PFM) function. DESIGN: One-to-one age- and parity-matched case-control study. SETTING: Akershus university hospital and one outpatient physiotherapy clinic in Norway. POPULATION: Forty-nine women with POP (POP quantification, stage>or=II) and 49 controls (stages 0 and I) were recruited from community gynaecologists and advertisements in newspapers. METHODS: Validated questionnaires, interview and clinical examination, including Beighton's scoring system (joint hypermobility) and vaginal pressure transducer measurements (PFM function), were used. Univariate and multivariate conditional logistic regression analyses for one-to-one matched case-control studies were used, and odds ratios with 95% CIs are reported. MAIN OUTCOME MEASURES: Pelvic floor muscle function (strength, endurance and resting pressure), socioeconomic status, body mass index, heavy occupational work, physical activity, family history, obstetric factors and markers of connective tissue weakness (striae, varicose veins, bruising, diastasis recti abdominis, joint hypermobility). RESULTS: No significant differences were found between groups with regard to postmenopausal status, current smoking, current low-intensity exercise, type of birth (caesarean, forceps, vacuum), birth weight, presence of striae, diastasis recti abdominis and joint hypermobility. Body mass index (OR 5.0; 95% CI 1.1-23.0), socioeconomic status (OR 10.5; 95% CI 2.2-50.1), heavy occupational work (OR 9.6; 95% CI 1.3-70.3), anal sphincter lacerations (OR 4.5; 95% CI 1.0-20.0), PFM strength (OR 7.5; 95% CI 1.5-36.4) and endurance (OR 11.5; 95% CI 2.0-66.9) were independently related to POP. CONCLUSIONS: Body mass index, socioeconomic status, heavy occupational work, anal sphincter lacerations and PFM function were independently associated with POP, whereas joint mobility and physical activity were not.

Interobserver repeatability of three- and four-dimensional transperineal ultrasound assessment of pelvic floor muscle anatomy and function.

OBJECTIVE: To evaluate the interobserver repeatability of measurement of the pubovisceral muscle and levator hiatus, and the position of related organs, during rest, muscle contraction and Valsalva maneuver using three- and four-dimensional (3D and 4D) transperineal ultrasound. METHODS: Seventeen women were included in the study. The position and dimensions of the pubovisceral muscle and levator hiatus in patients at rest and during contraction and Valsalva were determined from stored 3D and 4D ultrasound volumes. Analyses were conducted offline by two observers blinded to the clinical data and to each others' measurements. RESULTS: Measurements of levator hiatal dimensions at rest demonstrated intraclass correlation coefficient (ICC) values of 0.92 to 0.96. The ICC values for pubovisceral muscle thickness at rest varied between good and very good (ICC, 0.61-0.93), regardless of plane. During contraction, the ICC values for all measured parameters were very good, varying between 0.61 and 0.92. Measurement of the transverse diameter of the levator hiatus during the Valsalva maneuver showed good reliability (ICC, 0.86), but assessment of the anterior and posterior borders of the levator hiatus was only possible in 29% of cases. CONCLUSIONS: 3D and 4D transperineal ultrasound measurement of the pubovisceral muscle and levator hiatus is reliable in women with no or minor symptoms of prolapse at rest and during contraction. The technique for recording during the Valsalva maneuver requires improvement if it is to be useful in the diagnosis of pelvic organ prolapse.