MAGNETIC-RESONANCE-IMAGING OF THE PELVIS - NEW ORTHOPEDIC APPLICATIONS

A preliminary study of using magnetic resonance angiography to detect occult proximal thrombi in patients who had hip arthroplasty was done, Despite the presence of susceptibility artifact caused by metallic co mponents, diagnostic visualization of thigh vessels was made in a prel iminary series of 15 patients, Confirmation of all previously document ed (by contrast venogram via dorsal foot vein cannulation or Doppler s tudy) proximal thrombi was made in all 15 patients, One patient had a thrombus in the contralateral extremity that had been undetected by Do ppler study; 4 additional pelvic thrombi occurred in 3 patients, which had been undocumented previously, Because magnetic resonance angiogra phy is noninvasive, requiring no contrast agent, it has advantages ove r conventional venography to detect occult proximal thrombi, New fast spin echo sequences are discussed that enhance visualization of region al anatomic structures adjacent to metallic prosthetic components, Emp hasis was placed on assessing the posterior soft tissue envelope in pa tients having recurrent dislocations after total hip arthroplasty, des pite acceptable component alignment, Preliminary results show a consis tent absence of a posterior pseudocapsule in patients having dislocati ons, as compared with control patients having no dislocations.