| Objective:To investigate the value of prostate-bladder angle(PBA) measured by magnetic resonance imaging(MRI) in the diagnosis of benign prostate obstruction (BPO).Methods:We studied the clinical data of 87 benign prostatic hyperplasia(BPH) patients referred for lower urinary tract symptoms(LUTS) between March 2009 and November 2009. PBA was measured by MRI and urodynamic parameter Qmax was also measured. Using Qmax<10ml/s as the diagnosis criteria of BPO, we divided these patients into two groups:obstruction group and non-obstruction group. We compared the PBA between the two groups and analyzed its sensitivity and specificity in diagnosing BPO.Results:The mean age was 57～90 (73) years; Qmax was 2.3～25.4 (7.9) ml/s; PBA was 4-52 (27)°. With the diagnosis criteria of BPO as Qmax<10ml/s, the patients were divided into two groups:obstruction group and non-obstruction group. In the non-obstruction group, there were 25 patients and the PBA was 4-21(13)°; in the obstruction group, there were 62 patients and the PBA was 15-52 (34)°. PBA was found statistically different between the obstruction and non-obstruction group(P< 0.001). With the cutoff at PBA≥20°for the diagnosis of BPO, the sensitivity and specificity of the diagnosis were 90.3% and 96.0% respectively.Conclusion:PBA measured by MRI is significantly different between the obstruction and non-obstruction group of BPH patients. The criteria of PBA≥20°has high sensitivity and specificity in the diagnosis of BPO. PBA can be used as a new non-invasive parameter in the diagnosis of BPO. |
