Evaluation of Accuracy of Shear Wave Elastography and Superb Microvascular Imaging Methods in Diagnosis of Piriformis Syndrome: A Preliminary Study.

Abstract

Piriformis syndrome is a neuromuscular disease resulting from sciatic nerve compression caused by an abnormal condition in the piriformis muscle. Superb microvascular imaging (SMI) is a new ultrasound imaging technique that visualizes low-velocity and small-diameter blood vessel flow. In our prospectively designed study, we aimed to evaluate the accuracy of diagnosis of piriformis syndrome with innovative methods such as shear wave elastography (SWE) and SMI. Thirty-two patients diagnosed with unilateral piriformis syndrome were accepted to the statistical stage. The side without symptoms was considered the "unaffected side." Bilateral piriformis muscles were examined by ultrasonography. Muscle thickness was determined on gray scale, stiffness on SWE and vascularity characteristics on power Doppler and SMI by two independent radiologists. Piriformis muscle stiffness on the non-pathological (unaffected) side was measured by SWE as 18.27 ± 7.301 kPa, and the mean stiffness on the pathological side was 29.70 ± 10.095 kPa. Pathological side muscle stiffness was significantly higher (p < 0.05). Using innovative methods such as SWE and SMI in addition to conventional ultrasonography as much as possible in our daily practice and research helps us in making the correct diagnosis in piriformis syndrome.