Three-dimensional magnetic resonance imaging of the interosseous membrane of forearm: A new method using fuzzy reasoning

We now report newly developed three-dimensional magnetic resonance imaging (3D-MRI) system which is based on semiautomatic tissue extraction from the axial MR images utilizing the fuzzy reasoning calculation method and 3D-ima ge reconstruction with surface rendering. We also studied normal in vivo dy namic changes of the interosseous membrane (IOM) of forearm during rotation using this 3D-MRI. Serial axial MRI of right forearms of five healthy volu nteers was obtained in five rotational positions, and extraction and 3D-rec onstruction of the radius, ulna, and IOM was made using the system. Extract ion results were well with the fuzzy reasoning method. 3D-MRI of the radius and ulna, IOM were reconstructed from these images respectively, and their 3D-shapes were almost identical to the anatomic shape. 3D-MRI showed there were wavy deformities on the IOM in pronation position in the all five sub jects and dorsiflexion on the most dorsal portion of the IOM at maximum sup ination in three forearms. In neutral position, the IOM of all five volunte ers was almost flat. From anatomic orientation, these dynamic changes of th e IOM;I mainly occurred at the membranous portion, which is soft, thin, and elastic. Otherwise, the tendinous portion which is a thick and strong comp lex of 5 to 10 bundles run from proximal one third of the radius to distal one fourth of the ulna, demonstrated minimal dynamic changes on the 3D-MRI. Therefore, the tendinous portion is considered to be taut during rotation to provide stability between the radius and the ulna, while the membranous portion is easy to deform and allowing smooth rotation, Furthermore, becaus e of wide-use, our 3D-MRI system is useful for in vivo analysis of soft tis sue kinesiology in normal and abnormal musculoskeletal systems. (C) 1999 El sevier Science Inc.