Genitourinary Teaching File

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Acute Testicular Torsion

Nuclear Medicine

Flow and static images from a nuclear medicine testicular study show flow to both sides of the scrotum early on, but no flow to the left testicle on later imaging. The patient complained of left testicular pain, and the study findings are compatible with left testicular torsion.

Ultrasound

Grayscale image of both testes (straddle view) shows symmetrical echogenicity

Color Doppler evaluation shows normal flow to the right testis, but no flow to the left, compatible with acute left testicular torsion

Teaching Point:

Color Doppler gain settings should be optimized by using the non-symptomatic testis as a baseline. This will help to determine if the color flow pattern in the affected testis is increased, indicating hyperemia and orchitis, decreased, indicating partial torsion, or absent, indicating complete torsion.

Incidence

1:4000 males

peak age--newborn and puberty (13-16 years)

< 20 years in 74%

>21 years in 26%

>30 years in 9%

Etiology

Bell clapper deformity

high insertion of tunica vaginalis on spermatic cord

bilateral in 10%

abnormally loose mesorchium between testis and epididymis

undescended testes undergo torsion 10x more often than descended

Clinical

sudden onset of pain, usually at night, in 100%

negative U/A in 98%

history of similar episode in 42%

nausea and vomiting in 50%

scrotal swelling and tenderness in 42%

leukocytosis in 32%

low grade fever in 20%

history of trauma/extreme exertion in 13%

Salvage rate (time interval between onset of pain and surgery)

<6 hours 80-100%

6-12 hours 76%

12-24 hours 20%

>24 hours near 0%

spontaneous detorsion--7%

Ultrasound

80-90% sensitivity

testicular and epididymal enlargement with decreased echogenicity; may be normal early on

increased size of spermatic cord

scrotal skin thickening

hydrocele occasionally

loss of spermatic cord Doppler signal

44% sensitivity, 67% specificity

Case prepared by Anthony L. Alcantara, M.D.

Related case from Brigham and Women's Hospital, Department of Radiology, Harvard Medical School