Physical examination shows a swollen and tender testis, an absent cremasteric reflex, and pain not relieved by elevation of the scrotum above the level of symphysis pubis. Testicular torsion commonly presents with sudden onset of pain followed by nausea, vomiting, and absence of urinary symptoms. Partial torsion can also occur when the axis of the spermatic cord is rotated 360В°), which impairs both arterial inflow and venous outflow. It is associated with the bell-clapper deformity, a preexisting deformity in which the posterolateral aspect of the testes does not attach to the tunica vaginalis, allowing the testis to swing and rotate freely within the scrotum. Testicular torsion is most common in younger men, though it can occur at any age, with a prevalence of 1 in 4000 in males younger than 25 years of age. Testicular torsion occurs when the spermatic cord and testicle twist around its axis, resulting first in venous obstruction, followed by decreased arterial flow and subsequent testicular ischemia. Genital or para genital infection is the most common cause of the acute scrotum, followed by testicular torsion and testicular trauma. Scrotal pain is a common presenting complaint with a broad differential that ranges from acute diagnoses including testicular torsion, penetrating trauma, incarcerated inguinal hernia, and testicular rupture to non-acute diagnoses including epididymo-orchitis, appendicular torsion, and mild trauma. It is important for a practicing radiologist to be familiar with such cases to avoid unnecessary surgical interventions.We present a pictorial essay of cases in which the absence of testicular blood flow on color flow Doppler or abnormal waveforms on spectral Doppler are identified, without the presence of testicular torsion. Conditions that commonly mimic testicular torsion include incarcerated inguinal hernias and complications following hernia repair,thrombotic phenomena, vasculitis, complicated epididymo-orchitis, asymptomatic variants, and technical limitations of ultrasonography. However, it is important to consider that not all absence of blood flow or reversal of diastolic flow in testis represents testicular torsion, as other conditions may have a similar appearance, including rare detection of such a pattern in normal asymptomatic patients. Patients with partial testicular torsion may have reversal of arterial diastolic flow on spectral Doppler, decreased amplitude of the spectral Doppler waveform (parvus tardus wave), or monophasic waveforms. This imaging finding is seen in the vast majority of patients with testicular torsion, except in patients with partial torsion. The absence of blood flow in the testis on ultrasound examination is the gold standard for diagnosis of testicular torsion.

Testicular sonogram