Imaging Metabolic and Perfusion Changes in Acupuncture Therapy for Myofascial Pain Syndrome

Myofascial pain syndrome (MPS) is a musculoskeletal pain disorder characterized by localized muscle pain, trigger points, and functional limitations. MPS is frequently associated with chronic low back pain and contributes substantially to reduced quality of life and increased healthcare utilization. Despite its prevalence, diagnosis and treatment monitoring rely largely on subjective clinical examination and patient-reported outcomes because validated objective biomarkers of myofascial tissue dysfunction are lacking. Acupuncture is widely used as a non-pharmacologic treatment for chronic pain and has demonstrated benefit in several chronic low back pain studies. However, the biological mechanisms underlying acupuncture's therapeutic effects remain poorly understood, in part because objective measures of tissue-level response are limited. Total-body positron emission tomography/computed tomography (TB-PET/CT) is a highly sensitive molecular imaging technique capable of assessing metabolic activity and blood flow throughout the body. Recent observational work using TB-PET/CT has demonstrated the ability to differentiate painful myofascial tissue from non-painful tissue, suggesting that this technology may provide quantitative biomarkers of myofascial dysfunction. The IMPACT-MPS study is a two-arm, randomized, participant- and assessor-blinded, sham-controlled clinical trial designed to evaluate both the clinical efficacy of acupuncture and the utility of TB-PET/CT imaging biomarkers in MPS. A total of 64 adults with chronic low back pain associated with myofascial pain syndrome will be enrolled and randomized in a 1:1 ratio to receive either standardized acupuncture treatment or sham acupuncture. Participants will receive up to three acupuncture or sham sessions per week for eight weeks. TB-PET/CT imaging and patient-reported outcome assessments will be performed at baseline and at 8 weeks, with an optional imaging and assessment visit at week 4. Clinical outcomes will include standardized pain and function measures, including the PEG (Pain intensity, Enjoyment of life, General activity) scale and other NIH HEAL Common Data Elements. The primary clinical endpoint is the change in PEG score from baseline to 8 weeks. The primary imaging endpoint is the change in standardized uptake values in predefined myofascial regions of interest measured by TB-PET/CT. Secondary outcomes include additional patient-reported outcomes and imaging measures of myofascial tissue metabolism and perfusion. This study aims to determine whether acupuncture improves clinical outcomes in patients with myofascial pain syndrome and to evaluate TB-PET/CT as an objective imaging biomarker of myofascial tissue dysfunction and treatment response. The results may support the development of imaging-based tools for evaluating chronic musculoskeletal pain and monitoring treatment effects.