From the Research
An MRI of the thigh to evaluate a hamstring injury should typically be performed without contrast. For most hamstring injuries, non-contrast MRI provides excellent visualization of muscle tears, strains, edema, and hematoma formation without the need for gadolinium-based contrast agents, as noted in the most recent study 1. The T1-weighted images show anatomy and fatty infiltration, while T2-weighted and STIR sequences highlight edema and inflammation associated with acute injuries. Contrast is generally unnecessary because the pathology of hamstring injuries—including muscle fiber disruption, edema, and hemorrhage—is readily apparent on standard sequences. However, in specific situations such as suspected tumor, infection, or complex cases with prior surgery, contrast may be added to better characterize these conditions. The decision should ultimately be made by the radiologist and referring physician based on the clinical scenario, but for routine hamstring strain or tear evaluation, non-contrast MRI is the standard approach and provides all necessary diagnostic information while avoiding the small risks associated with contrast administration.
Some key points to consider when evaluating hamstring injuries with MRI include:
- The location of the injury within the muscle-tendon unit, as noted in 2
- The extent of the injury, which can be assessed using MRI and ultrasound, as discussed in 3
- The presence of any ancillary findings, such as avulsion fractures or hematoma, which can impact treatment and prognosis, as mentioned in 4
- The use of standardized landmarks and detailed descriptions of tendon retractions to improve communication between radiologists and surgeons, as suggested in 4
Overall, the use of non-contrast MRI for the evaluation of hamstring injuries is supported by the most recent and highest quality evidence, including the study by 1, which highlights the importance of anatomy, imaging findings, and mechanisms of injury in the assessment of hamstring sports injuries.