Do Not Get It Twisted

Abstract

Color flow and spectral Doppler ultrasound are the backbone of scrotal imaging when evaluating acute scrotal pain. Testicular Torsion is one of the most common causes of acute scrotal pain but can be a challenging diagnosis both clinically and sonographically. This article will review the pertinent Doppler ultrasound findings that can help make the diagnosis of both complete and partial torsion. A review of other causes of testicular ischemia will also be included as these pathologies can mimic Testicular Torsion.

Testicular Torsion with Intact Blood Flow: A Point of Care Ultrasound Case-Series

“…Edema of the scrotum can be seen as well 4 . However, the presence of venous flow in the testis is difficult to record, and its presence or absence does not confirm presence or absence of torsion 5 .…”

“…This can result in absent or reversed waveforms as edema impedes or reverses forward flow; absence of a dicrotic notch resulting in a monophasic waveform (absence of diastolic flow between systolic peaks); or high amplitude waveforms indicating increasing resistance to flow (Figures 1,2) 6 , 7 . Conversely, arterial waveform may show a ‘tardus parvus’ pattern with low amplitude and slow upstroke, as seen in stenotic vessels (Figure 3) 8 . Resistive index (peak systolic velocity minus end diastolic velocity, with the difference divided by peak systolic velocity) normally ranges from 0.48-0.75 in children, and an elevated resistive index is indicative of compromised perfusion 1 , 9 .…”

“…Peripheral flow is not uncommon in testicular torsion and areas of increased echogenicity may be seen secondary to local hemorrhage. Typically, a twist of 450 degrees or more causes complete occlusion of blood flow to the testis 5 . Prolonged ischemia will cause marbling of the testis and correlates with poor prognosis 10 .…”

“…Presence of the ‘whirlpool sign’ indicating a knotted cord complex (Figure 4, Video S2) is diagnostic of torsion, even in the presence of intact testicular blood flow 8 . While the ‘pseudomass’ is used to denote the knotted cord, it actually refers to the complex of edematous epididymis, vas deferens, and distal cord vessels that cannot be distinguished sonographically 4 .…”

“…However, none of the above POCUS studies address the rare event of torsion with preserved flow. Central testicular blood flow can be seen in an incompletely torsed testicle or in children with thinner spermatic cords that limit the pressure placed on the vessels 8 . Testicular pain that resolves suddenly, with normal flow on POCUS, may warrant urology consultation to evaluate for intermittent torsion 14 .…”