Penile and scrotal emergencies are uncommon, but when they do occur, urgent or 
emergent diagnosis and treatment are necessary. Emergent conditions of the male 
genitalia are primarily infectious, traumatic, or vascular. Infectious 
conditions, such as epididymitis and epididymo-orchitis, are well evaluated at 
ultrasonography (US), and their key findings include heterogeneity and 
hyperemia. Pyocele and abscess may also be seen at US. Fournier gangrene is best 
evaluated at computed tomography, which depicts subcutaneous gas. Vascular 
conditions, such as testicular torsion, infarction, penile Mondor disease, and 
priapism, are well evaluated at duplex Doppler US. The key imaging finding of 
testicular torsion and infarction is a lack of blood flow in the testicle or a 
portion of the testicle. Penile Mondor disease is characterized by a lack of 
flow to and noncompressibility of the superficial dorsal vein of the penis. 
Clinical examination and history are usually adequate for diagnosis of priapism, 
but Doppler US may help confirm the diagnosis. Traumatic injuries of the penis 
and scrotum are initially imaged with US, which depicts whether the penile 
corpora and testicular seminiferous tubules are contained by the tunicae 
albuginea; herniation of contents and discontinuity of the tunica albuginea 
indicate rupture. In some cases, magnetic resonance imaging may be performed 
because of its ability to directly depict discontinuity of the tunica albuginea. 
Radiologists must closely collaborate with emergency physicians, surgeons, and 
urologists to quickly and efficiently diagnose or rule out emergent conditions 
of the male genitalia to facilitate prompt and appropriate treatment.