J Korean Soc Med Ultrasound.  2002 Mar;21(1):23-30.

Comparison of Methods of Volume Measurement of the Prostate by Transrectal Ultrasound: Experiment with Jelly Models

• Cho JY
• Lee HJ
• Kim SH
• Kim SH

Abstract

PURPOSE: To compare the accuracy of measuring the volume of the prostate using the prolate ellipsoid volume calculation method [antero-posterior (AP) diameter x length x width x pi/6] when the antero-posterior diameter of the prostate was measured on midsagittal (sagittal volume) and axial plane (axial volume).
MATERIALS AND METHODS
The devil 's tongue jelly was used for the creation of an ultrasound model of the prostate (volume: 15-40 cc) by cutting and shaping the surface. The volume in 10 prostatic models and 30 patients was measured and calculated. First, the AP diameter and length of the prostatic models in midsagital plane, and the height and width of the models in axial plane were measured for 3 times. The volume was calculated in two ways, one using the AP diameter in midsagital plane and the other using the AP diameter in axial plane. The true volume of the model was measured using mess cylinder. The calculated volume and true volume were compared, and the accuracy of two method of measuring the prostatic volume was evaluated by Friedman test. The intraobserver variation was evaluated by General Linear Model, Repeated Measure. The reproducibility was evaluated by Cronbach 's alpha In vivo study was also performed in 30 patients. The prostate volume was calculated in the same manner. These volume data were analyzed by statistical method, and the intraobserver variation was evaluated.
RESULTS
While there was a statistically significant difference between the sagittal and true volumes of the models, there was no statistical significant difference between the axial and true volumes. There was no significant intraobsever variation between both methods. The reproducibility was high in both methods with Cronbach 's alphaf 0.977 and 0.942. The sagittal volume was larger than the axial volume in 30 patients with a statistically significant difference. There was no significant intraobsever variation in both methods. The reproducibility was high in both methods with Cronbach 's alphaf 0.991 and 0.994.
CONCLUSION
The volumetric method for the prostate using the anteroposterior diameter measured in axial plane was more accurate than that on midsagittal plane.

MeSH Terms

Humans
Linear Models
Observer Variation
Phosmet
Prostate*
Tongue
Ultrasonography*
Phosmet