<prompt> Penile angiography is reliable only after intracavernosal injection of vasoactive substances. All are indications for penile angiography, EXCEPT:Painful priapismPeyronies diseaseErectile dysfunctionAeriovenous malformation  <response>: Priapism is a prolonged, unwanted erection not associated with sexual stimulation. It is classified as low-flow venous and high-flow aerial priapism. Doppler US can distinguish the type of priapism, with low-flow priapism showing decreased or no blood flow in the cavernosal aeries. The most reliable method, however, involves testing aspirated blood from the corpus cavernosum for blood gas analysis. Ref: Liu D.R. 2011. Chapter 127. Urologic and Gynecologic Problems and Procedures in Children. In J.E. Tintinalli, J.S. Stapczynski, D.M. Cline, O.J. Ma, R.K. Cydulka, G.D. Meckler Eds, Tintinallis Emergency Medicine: A Comprehensive Study Guide, 7e. 