RESUMO
OBJECTIVE: To determine the utility of prostate ultrasound in the diagnosis of infravesical obstruction (IVO) and detrusor hyperactivity(DH). METHODS: 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. RESULTS: 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. CONCLUSION: 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.
