[Erectile dysfunction: the role of Rigiscan in the diagnosis].Acta Urol Belg. 1996 Mar; 64(1):43-5.AU
Nocturnal penile tumescence (NPT) was performed in all patients and was evaluated as normal or abnormal according to standardized general criteria. The results of NPT were then compared to penile duplex ultrasonography parameters peak systolic velocity (normal > 35 cm/sec) and diastolic velocity (normal < 5 cm/sec), and to the flow rate needed to maintain erection (normal < 15 ml/min) with pharmaco-infusion cavernosometry.
Of the 50 patients, 26 showed normal NPT where 25 patients (96%) had normal penile systolic velocity, 18 patients (69%) had normal penile diastolic velocity, and 22 patients (85%) showed normal flow to maintain erection. On the other hand, 24 showed abnormal NPT, where 7 patients (29%) had abnormal penile blood flow velocity and 18 patients (75%) showed high flow rate to maintain erection.
From this study, we can conclude that normal NPT appears to have a good correlation with normal systolic blood velocity and normal cavernosometry. However, this correlation is low when compared with diastolic blood velocity. On the other hand, a low correlation exists between abnormal NPT and abnormal systolic and diastolic blood flow or abnormal cavernosometry. According to this observation, we can presumed that NPT, penile duplex and infusion cavernosometry considering together should be performed in order to achieve a reasonably accurate diagnosis.