Evaluation of Intramuscular Tissue Perfusion in PRICE Therapy using Contrast-Enhanced Ultrasound

Introduction To investigate intramuscular tissue perfusion (ITP) in athletes before, during, and after protection, rest, ice, compression, elevation (PRICE) therapy in sport-specific conditions and to prove the hypothesis of reactive hyperemia after PRICE therapy.

Material and Methods Twenty healthy athletes (11 women, 9 men; mean ± SD age: 25 ± 3; range: 21–30 years; body mass index: 23 ± 3 kg/m²) were randomized to PRICE or a control group. Quantifiable contrast-enhanced ultrasound was assessed to analyze microvascular blood flow of the anterior thigh (rectus femoris muscle [RF] and vastus intermedius muscle [VI]). Baseline perfusion measurements (t₀) were compared with exercise (cycling, t₁), intervention (PRICE or control [rest], t₂), and a 60-minute follow-up (t₃). PRICE included rest, cryotherapy (3°C), compression (35 mm Hg), and elevation.

Results After cycling, an upregulation of ITP was observed in the VI and RF for both groups. The PRICE measurements revealed a decrease of ITP, corresponding to a 47% and 53% decrease in the VI (wash-in area under the curve, peak enhancement [WiAUC, PE]; p = 0.01, not significant [NS]) and a 50% and 72% decrease in the RF (p = 0.037; p = 0.002). In contrast, an increase of ITP was observed for the control group at t₁ and t₂. At t₃ the superficial RF (PRICE) revealed a persistent decrease of 15% and 50% (NS; p = 0.003), whereas the RF (control) and VI (both groups) showed no significant changes to baseline conditions.

Conclusion Our study highlights the fundamental impact of PRICE on ITP. PRICE applied after exercise leads to a downregulation of microvascular blood flow in superficial as well as deep muscle layers. The termination of PRICE is not associated with a reactive hyperemia.