title: Magnetic resonance signal alterations in the acute onset of heterotopic ossification in patients with spinal cord injury.
abstract: The purpose of our study was to evaluate magnetic resonance (MR) signal characteristics of acutely forming heterotopic ossification (HO) in paralyzed patients. Fourteen patients with spinal cord injury (female n=2, male n=12, mean age 38.3 years) and acute onset of radiographically proven HO had contrast-enhanced 1.5-T MRI within 13.4+/-18.3 days of clinical onset of symptoms. MR signal alterations of affected muscles, fascia, subcutaneous tissue, skin and adjacent bone were evaluated. A diffuse T2-hyperintense signal of multiple muscle groups was seen in all patients (bilateral in 12) involving quadriceps (n=13, 93%), adductors (n=13, 93%) and iliopsoas (n=12, 86%) with contrast enhancement in n=11 (79%), n=8 (57%) and n=8 (57%) patients. All patients had nonenhancing areas (mean size 2 x 3.5 x 5.8 cm) within diffusely enhancing muscles. HO formation occurred around these nonenhancing areas in four patients with computed tomography follow-up. Other MR findings included fascial edema (n=14, 100%), fascial enhancement (n=13, 93%), subcutaneous edema (n=13, 93%), subcutaneous enhancement (n=12, 86%), bone marrow edema (n=5, 36%), and joint effusion (n=12, 86%). MRI reveals mostly bilateral edema and enhancement of muscles, fascia and subcutaneous tissue during acute onset of HO. HO develops in the periphery of well-defined areas of no enhancement.
authors.affiliation: Radiologie, Schweizerisches Paraplegikerzentrum, 6207, Nottwil, Switzerland. wicklukas@yahoo.de
authors.forename: L
authors.initials: L
authors.lastname: Wick
authors.forename: M
authors.initials: M
authors.lastname: Berger
authors.forename: H
authors.initials: H
authors.lastname: Knecht
authors.forename: T
authors.initials: T
authors.lastname: Glücker
authors.forename: H P
authors.initials: HP
authors.lastname: Ledermann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001855:Bone Marrow Diseases / Q000175:diagnosis; D003287:Contrast Media; D004487:Edema / Q000175:diagnosis; D005205:Fascia / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000175:diagnosis; D009140:Musculoskeletal Diseases / Q000175:diagnosis; D009999:Ossification, Heterotopic / Q000175:diagnosis*; D010264:Paraplegia / Q000150:complications; D016658:Psoas Muscles / Q000473:pathology; D011782:Quadriplegia / Q000150:complications; D012871:Skin Diseases / Q000175:diagnosis; D013119:Spinal Cord Injuries / Q000150:complications*; D013582:Synovial Fluid; D013848:Thigh / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media