IS case 528: Testicular detorsion
Imaging Sciences URMC 2010
Publication Date: 2010-09-11
Initial ultrasound image of the right testicle demonstrated decreased flow to the right testicle with dampened arterial waveforms. The testicle was also displaced superiorly. The left testicle showed a normal waveform pattern. During the exam, the patient suddenly felt better, and repeat ultrasound of the right testicle showed increased flow (when compared to the left testicle and itself while torsed) with movement of the testicle back into the scrotum.
Testicular torsion is due to faulty attachment of the testicle to the scrotal wall. During testicular torsion, the first hemodynamic consequence is venous obstruction, followed by obstruction of arterial inflow, thus causing testicular ischemia. The viability of the testicle is dependent on the duration of ischemia and the number of twists of the spermatic cord. For this reason, it is important to be able to diagnose testicular torsion immediately and accurately so that the testicle can be saved.
Unfortunately, grayscale ultrasound is not very useful in diagnosing testicular torsion due to the possibility of a normal study. Nonspecific findings include: decreased testicular echogenicity, testicular edema, and reactive hydroceles. It is useful, however, to estimate the viability of the testicle. If the testicle is normal on grayscale then the testicle is likely viable. If the testicle is hypoechoic or inhomogeneous then it is likely infarcted, and therefore, nonviable.
Color Doppler is extremely useful in detecting testicular torsion due to the absence of or decreased vascularity in the testicle of question when compared to the other testicle. In cases of prolonged torsion, a hyperemic scrotal wall is noted secondary to an inflammatory reaction within the soft tissue. Following detorsion, increased flow is seen in the testicle, also known as reactive hyperemia, and is an effective means of documenting detorsion.
One pitfall for testicular torsion are false-negative findings. These occur when torsion is intermittent, low-grade, or spontaneously resolves prior to ultrasound. It is important to understand this limitation, as these patients may eventually have an infarcted testicle.
- Middleton W, Kurtz A. Ultrasound: The Requisites, 2nd ed. St. Louis: Mosby, 2004.