COMPARISON OF PENILE DUPLEX ULTRASONOGRAPHY TO PUDENDAL ARTERIOGRAPHY- VARIANT PENILE ARTERIAL ANATOMY AFFECTS INTERPRETATION OF DUPLEX ULTRASONOGRAPHY

RATIONALE AND OBJECTIVES. Duplex ultrasonography is currently used as a noninvasive imaging modality for the functional evaluation of penile blood flow in impotent men. However, the accuracy of this test is con troversial. The objective of this study was to determine the sensitivi ty and specificity of duplex ultrasonography, to assess the ultrasonog raphic parameters most predictive of arterial disease, and to evaluate the causes of misinterpretation of duplex ultrasound studies. METHODS . Duplex ultrasonography and pudendal arteriography were performed on 42 impotent men during a 4-year prospective study. The predictive powe r of the following ultrasonographic parameters were analyzed: cavernos al arterial diameter, peak blood flow velocity, and pulsations on real -time ultrasonography. RESULTS. The results of both studies were conco rdant in 81 % of the patients with a 77 % sensitivity and 85 % specifi city for ultrasonography when using arteriography as the gold standard . Arterial pulsations and peak blood flow velocity were most predictiv e, whereas dilation was not helpful. Variant penile arterial anatomy w as present in 83% of the patients and was the most frequent cause of m isinterpretation of duplex ultrasonography. CONCLUSION. Duplex ultraso nography is a fairly reliable screening test for arterial disease in i mpotent men. Visualization of arterial pulsations and measurement of p eak blood flow velocity are the best predictors of arterial function. Awareness of the potential arterial anomalies may help reduce misinter pretation of ultrasonography. Arteriography is necessary in any patien t being considered for penile arterial surgery because of the high fre quency of anatomic variations.