Residual urine determination by ultrasonic scanning

Area of Science:

• Urology
• Medical Imaging
• Diagnostic Techniques

Background:

• Accurate bladder volume measurement is crucial for patient care, especially for those with indwelling catheters.
• Various non-invasive ultrasonic methods exist for estimating bladder volume.
• The accuracy of these methods can vary, necessitating comparative studies.

Purpose of the Study:

• To evaluate and compare the accuracy of five different ultrasonic methods for determining bladder volume in patients with indwelling catheters.
• To identify the most reliable ultrasonic technique for bladder volume estimation.

Main Methods:

• Utilized five distinct ultrasonic methods to measure bladder volume in 14 patients with indwelling catheters.
• Performed 48 separate bladder volume determinations.
• Compared ultrasonic measurements against true bladder volume.

Main Results:

• The simplest method, measuring the largest sagittal diameter, provided only a rough estimate.
• The product of bladder depth, height, and width, derived from transverse and sagittal scans, demonstrated the highest correlation with true bladder volume (r=0.90).
• Computerized reconstruction of serial cross-sections was less accurate than the depth, height, width product.
• Quantitative assessment of small bladder volumes was inaccurate across all tested methods.
• Qualitative assessment of small bladder volumes was accurate.

Conclusions:

• The depth, height, and width product is the most accurate ultrasonic method for estimating bladder volume in patients with indwelling catheters.
• Current ultrasonic methods struggle with accurate quantitative measurement of small bladder volumes.
• Qualitative ultrasonic assessment remains effective for identifying small bladder volumes.