DIAGNOSIS AND FOLLOW-UP OF MUSCLE INJURIE S BY MEANS OF PLAIN AND CONTRAST-ENHANCED MRI - EXPERIMENTAL AND CLINICAL OBSERVATIONS

Purpose: To clarify the value of plain and contrast-enhanced MRI for t he diagnosis and follow-up of muscle injuries, by means of experimenta l and clinical studies. Method: 24 Wistar rats were studied following standardized division of the calf muscles by means of MRI carried out on the first day, and also after one, two, three and four weeks. In ad dition, 16 patients with muscle injuries were examined (32 examination s), first between the first and fifth day of trauma, and subsequently over a period of two to seven weeks (average: four weeks). Results: In the animal experiments, there was signal reduction of T-1 and an incr ease of the T-2-weighted signal during the acute inflammatory phase. D uring the subacute reparative phase, there was an increase of both the T-1-weighted and T-2-weighted signals. These became reduced during th e chronic healing phase. Early differentiation between intramuscular h aematomas and bleeding, surrounding oedema and recognition of the divi ded muscle fibres was possible only after the intravenous injection of an MR contrast medium (Cd-DTPA). Suture of the divided muscles result ed in more rapid healing without major defects. Conclusion: It is poss ible to follow up the healing process after muscle injuries by means o f plain MR. Contrast-enhanced MR allows early evaluation of muscle abn ormalities, and is particularly valuable for recognising the margins o f the injured muscles.