Rigiscan versus snap gauge band measurements: is the extra cost justifiable?

Both RigiScan and the Snap Gauge band devices are used to objectively measure penile rigidity. The Snap Gauge band is the more simple and inexpensive of the two techniques. We investigated the correlation between the results obtained by both devices in order to evaluate whether the Snap Gauge band could be employed as the sole method of rigidity evaluation while not affecting the quality of diagnosis. Forty eight patients who were presented to our erectile dysfunction clinic used the two devices simultaneously, each according to the accepted protocols. Breakage of two and three strings of the Snap Gauge (good rigidity) correlated well with good tip and average rigidity as evaluated by the RigiScan. Snap gauge results also correlated with duration of erection, number of erections, the number of adequate erections, and the longest duration of erection measured by the RigiScan. Therefore, good rigidity according to the Snap Gauge test correlated well with the results of functional erections (number, rigidity, duration) as obtained by the RigiScan. The Snap Gauge band can be used to adequately evaluate penile rigidity. RigiScan measurements, which are more complicated and more expensive, should be reserved for selected patients in whom the results of the Snap Gauge band are inconclusive or when more detailed information is required.