Ultrasonic Determination of the Residual Bladder Volume

Abstract

In a clinical study the ultrasonic determination of the residual bladder volume is evaluated by applying several echographic methods described in the literature. 163 patients (age 3–89 years, 114 males and 49 females) and 13 students were examined. Only in the latter group the bladder volume was also determined by a planimetric method. The most practical method showed a good agreement (with a maximum deviation of 25%) between the ultrasonically measured volumes and the volumes measured by catheterization in 66% of the cases. This method makes use of the formula V_us = 0.5(V_t + V₁), where V_us = residual volume estimated by ultrasonography; V_t = volume measured by the computer using the largest transversal ultrasonic bladder section, and V₁ = volume measured for the largest longitudinal section). Factors that influence image quality and accuracy because of changes in the form of the bladder were analyzed. The magnitude of the residual volume determined the image quality and the accuracy above all: lower volumes give worse images and are less accurate. Other factors seem to be relatively unimportant. To avoid discomfort, caused by urine tract infection and urethral strictures, ultrasonic determination of the residual urine is recommended for clinical application.

Ultrasonic Validation of Residual Bladder Volume in Postvaginal Hysterectomy Patients

“…Also, we would have to establish the cutoff point for moving from one formula to another. We agree with Hendrix et al [21] that it is inappropriate to compare results of various studies for the following reasons.…”

“…(2) There are differences in image quality among the various companies producing ultrasonographic equip ment, depending upon the the type and stage of develop ment [21], (3) There are differences in sample populations. Braun and Hofman [22] made a comparative investiga tion of different methods on the same population.…”

Ultrasonographic evaluation of bladder volume in young children

“…However, some authors found that ultrasonic assessment of bladder volume was not accurate enough to replace catheterisation [8]. Insufficient accuracy has been ascribed to poor images of the bladder and large variations in bladder shape [6]. Lower volumes give poorer images and are less accurate [6].…”

“…Insufficient accuracy has been ascribed to poor images of the bladder and large variations in bladder shape [6]. Lower volumes give poorer images and are less accurate [6]. To improve accuracy some authors proposed new scanning methods such as transvaginal [9] or transrectal application [10].…”

“…We estimated bladder volumes using the two regression equations determined in the previous and the present studies and compared the estimated volumes with actual bladder volumes. Percentage errors, mean percentage errors, standard deviations and percentage of cases with errors of more than 25% were analysed [6]. The Mann-Whitney test and a paired t-test were used for statistical analysis.…”