PURPOSE: We evaluated the usefulness of MR imaging for aggressive fibromatoses in order to determine tumor extent. MATERIALS AND METHODS: 17 lesions of 16 patients were examined with a 1.5-Tesla MR unit with unenhanced and gadolinium-enhanced T1WI, and T2WI. We retrospectively reviewed the MR features. RESULTS: The tumor had a smooth margin in 41% of cases, while an irregular margin was present in 59%. A low signal intensity band (LSB) followed a normal muscle tendon or fascia. LSBs were seen in all of the lesions with an irregular margin, but not in those with a smooth margin. LSB resembled thickened or uneven tendons. Five of the seven lesions with LSB had a positive surgical margin at the LSB on pathological feature, and they recurred. CONCLUSION: Detection of LSBs on MR images is important for the determination of tumor extent, which allows the surgical method to be decided and postoperative recurrence predicted.
PURPOSE: We evaluated the usefulness of MR imaging for aggressive fibromatoses in order to determine tumor extent. MATERIALS AND METHODS: 17 lesions of 16 patients were examined with a 1.5-Tesla MR unit with unenhanced and gadolinium-enhanced T1WI, and T2WI. We retrospectively reviewed the MR features. RESULTS: The tumor had a smooth margin in 41% of cases, while an irregular margin was present in 59%. A low signal intensity band (LSB) followed a normal muscle tendon or fascia. LSBs were seen in all of the lesions with an irregular margin, but not in those with a smooth margin. LSB resembled thickened or uneven tendons. Five of the seven lesions with LSB had a positive surgical margin at the LSB on pathological feature, and they recurred. CONCLUSION: Detection of LSBs on MR images is important for the determination of tumor extent, which allows the surgical method to be decided and postoperative recurrence predicted.