Application of Acoustic Radiation Force Impulse Elastography in Imaging of Delayed Onset Muscle Soreness: A Comparative Analysis With 3T MRI.

Context: Delayed onset muscle soreness is one of the most common reasons for impaired muscle performance in sports and is associated with reduced muscle strength and frequently observed both in professional and recreational athletes.

Objective: To emphasize the diagnostic value of acoustic radiation force impulse (ARFI) in imaging of delayed onset muscle soreness by comparing findings with high-resolution 3T magnetic resonance imaging T2-weighted sequences.

Design: Case series.

Setting: Laboratory environment.

Participants: Fifteen healthy students (7 females and 8 males; mean [SD]: age 24 [4] y, height 178 [10] cm, body weight 67 [12] kg).

Main Outcome Measures: ARFI values, represented as shear wave velocities of the gastrocnemius muscle and soleus muscle, as well as conventional ultrasound, high-resolution 3T magnetic resonance imaging, creatine kinase activity, extension range of the ankle joint, calf circumference, and muscle soreness were assessed before (baseline) and 60 hours after (postintervention) a standardized eccentric exercise.

Results: ARFI shear wave velocity values of the gastrocnemius muscle revealed a statistically significant decrease of 19.1% between baseline (2.2 [0.26] m/s) and postintervention (1.78 [0.24] m/s); P = .01. At follow-up, the magnetic resonance imaging investigations showed intramuscular edema for the gastrocnemius muscle in all participants corresponding to a significant raise in T2 signal intensity (P = .001) and in T2-time values (P = .004).

Conclusions: ARFI elastography seems to be an additional sensitive diagnostic modality in the diagnostic workup of delayed onset muscle soreness. Intramuscular shear wave velocities could represent an additional imaging marker for the assessment and monitoring of ultrastructural muscle injuries and therefore be helpful for individual training composition in elite sports.