Usefulness of bladder-prostate ultrasound in the diagnosis of obstruction/hyperactivity in males with BPH

To determine the utility of prostate ultrasound in the diagnosis of infravesical obstruction (IVO) and detrusor hyperactivity(DH).

Prospective study with 39 patients consulting for LUTS. Clinical history was compiled, IPSS was determined, a digital rectal exam was performed, abdominal ultrasound was used to calculate detrusor thickness/weight, prostate volume, and middle lobe length (MLL). Urodynamic study (UD) was performed with determination of the Abrams-Griffiths number and ICS nomogram. Mean values were compared with Mann-Whitney U-test, and ROC curves were plotted determining the cutoff points for optimum sensitivity/specificity.

Mean age was 63.1 years (SD: 7.8), with a mean IPSS score of 14 (SD: 6). 53.8% of the patients presented IVO at UD evaluation, and 43.6% DH. The differences between free flowmetry Qmax(p=0.015) and MLL (p=0.003) between patients with and without IVO proved significant. The ROC curves yielded an AUC for middle lobe length of 0.772, with a maximum sensitivity and specificity cutoff point at 10.5 mm (sensitivity 90%, specificity 73%, PPV 76%, NPV 85%). There were no significant differences in any parameter between patients with and without DH.

Ultrasound MLL measurement in patients with LUTS offers high sensitivity/specificity in diagnosing IVO, with a cutoff point of 10.5 mm. In our study it wasn't effective in the noninvasive diagnosis of DH.