Accuracy of ultrasound-measured bladder wall thickness for the diagnosis of detrusor overactivity

Abstract

Objectives: To evaluate the usefulness and accuracy of ultrasound measured urinary bladder wall thickness (BWT) in the diagnosis of detrusor overactivity (DO).

Subjects and methods: Patients who had undergone urodynamic testing due to irritative lower urinary tract symptoms (LUTS) were evaluated for participation in this study. All patients were submitted to thorough history taking, general physical and genital examination, urine analysis, urine culture, blood chemistry, uroflowmetry and abdominal ultrasonography. The patients were categorized into 2 groups according to the urodynamic diagnosis: group 1 consisted of 62 patients with documented DO and group 2 of 36 patients with no evidence of DO (controls). Ultrasound measurement of BWT was performed with the bladder filled with 50 ml of normal saline solution. The data were analyzed and the results of both groups were compared using suitable analytical tests.

Results: The age and gender distribution were comparable. Urgency was the main symptom in both groups. Mean BWT measured by ultrasound was significantly higher in group 1 than in group 2 (5.54 ±
1.95 mm versus 3.22 ± 0.84 mm, p < 0.001) with an overall sensitivity of 91.9% in predicting DO at a cutoff point of 3.75 mm.

Conclusions: Measurement of BWT using ultrasonography is a sensitive diagnostic test for the prediction of DO. Further studies on a larger number of patients are required to validate these results.

Keywords: Detrusor overactivity; Ultrasound; Bladder wall thickness; LUTS; Urodynamic study