MRI Evaluation of Bone and Soft Tissue Lesions Using a 3D mDIXON FFE Technique
Purpose or Case Report: The objective of this work was to determine whether a 3D gradient echo-based mDIXON T1-weighted sequence can replace a TSE-based mDIXON sequence in the evaluation of bone and musculoskeletal soft tissue lesions. Methods & Materials: 17 cases were reviewed in which patients had either a bone or soft tissue lesion and imaging was obtained using the classic mDixon- TSE sequences and the new mDixon- FFE sequences. The mDixon- FFE technique is a volumetric 3D sequence which can provide reformats in all 3 planes. In addition it uses a 7 peak model for shimming which provides better homogeneity on fat saturated images. Cases were reviewed by fellows and attending radiologists for image quality and lesion delineation. Age ranges for patients with bone lesions was between 7 years and 14 years old. Bone lesions included Desmoid, Ewing’s Sarcoma, Aneurymsal Bone Cyst, and Osteoid Osteoma among others. Age ranges for patients with soft tissue lesions varied between 8 months and 14 years old. Soft tissue lesions included abscess, myositis, fasciitis, venous malformation, and sebaceous cyst among others. Results: It was widely agreed that the mDixon- FFE sequence provided superior lesion delineation and image quality as compared to the mDixon-TSE sequence. Conclusions: Our preliminary study demonstrates that the mDixon- FFE sequence is superior to the mDixon- TSE sequence and should be considered as a replacement in evaluation of bone and MSK soft tissue lesions. It has superior resolution, shorter scan time, better image quality, smaller slices, and is a volumetric 3D sequence allowing for multiplanar reformatted images. While our reviewers agree that the overall image quality is superior with the gradient echo sequence our pictoral essay will show numerous examples of our gradient mDixon and our TSE mDixon with numerous different osseous and soft tissue lesions.