551 A novel algorithm for assessment of penile fibrosis in men with erectile dysfunction

Abstract

Corporal erectile tissue fibrosis is a significant pathophysiologic component of erectile dysfunction (ED), however current ultrasound-based penile imaging protocols do not directly assess it. Veno-occlusive dysfunction, quantified by elevated end diastolic velocity (EDV) of the penile cavernosal artery, a common surrogate for fibrosis, cannot identify site-specific lesions. In addition, EDV may only be abnormal in advanced disease states. Signal analysis of heterogeneity on B-mode ultrasound of other venous-sinus based tissue (i.e., liver) has been correlated to clinical fibrosis-based disease states. We developed a B-mode ultrasonographic imaging protocol for assessment of penile corporal heterogeneity that correlates to EDV to serve as a foundation for processing and categorizing corporal fibrosis images. Following pharmacologic erection, B-mode ultrasound (Aixplorer 15.4 mHz transducer) was performed. Images were captured in the axial plane at the proximal, mid, and distal shaft with gain of 45%, 55%, 65% and dynamic range 70 kB, followed by gain 30% (dynamic range 30-40 kB) for high contrast image. Subjects were grouped into homogenous (Group 1, n=42) mildly heterogeneous (Group 2, n=64), and moderate-severely heterogeneous (Group 3, n=53) by gross assessment of corporal tissue heterogeneity by the clinician. High-reliability assessment of EDV was performed using combined color and pulsed-wave (UltraFastTM) Doppler of the cavernosal artery.