SWE boosts diagnosis of plantar fasciitis

Shear wave elastography (SWE) improves the diagnostic accuracy in patients with plantar fasciitis (PFis), reported authors of a recent study published in Academic Radiology.

And when SWE is paired with B-mode ultrasound (B-US) its diagnostic accuracy only improved.

“The present study showed for the first time, that SWE has an additive diagnostic value for diagnosing PFis with a sensitivity of 100% for the combined usage of SWE and B-US,” wrote Matthias Gatz, MD, with University Hospital TWTH Aachen’s Department of Orthopedics in Aachen, Germany, and colleagues. “Additionally, the diagnostic accuracy increased from 79% using B-US to 84% using SWE.”

Currently, PFis is diagnosed using B-US to find hypoechoic areas, border irregularities and calcifications. And research shows that plantar fascia thickness of greater than 4 millimeters is the most telling parameter for determining PFis. However, fascia thickness can decrease over time and B-US has been shown to miss fascia patients, the authors noted.

With that in mind, Gatz and colleagues set out to compare B-US and SWE’s ability to analyze fascia stiffness and thickness.

The team divided 82 patients with plantar fascia into three groups: symptomatic (39 patients), control (23) and bilateral asymptomatic (20). Reference standard was defined as a PF thickness greater than 4 mm. They measured the sensitivity, specific and diagnostic accuracy of SWE and B-US and determined the measurements’ correlation to the American Orthopedic Foot and Ankle Score and Food Functional Index.

Overall, SWE proved more sensitive and diagnostically accurate compared to B-mode ultrasound. Specifically, SWE’s sensitivity was 85%, it achieved a specificity of 83% and diagnostic accuracy of 84%. In comparison, the sensitivity, specificity and accuracy of B-US was 61%, 95% and 79%, respectively.

When combined, the method achieved a diagnostic accuracy and sensitivity of 90% and 100%, respectively.

The results, according to the authors, suggest a need to revisit whether B-US should be the go-to for diagnosing PFis.

“SWE provides a quantitative assessment of PF integrity and can distinguish between symptomatic and asymptomatic patients better than B-US,” the researchers concluded. “Therefore, further studies need to reevaluate if B-US is still the gold standard in the diagnosis of PFis.”