MR imaging with metal artifact-reducing sequences and gadolinium contrast agent in a case-control study of periprosthetic abnormalities in patients with metal-on-metal hip prostheses.
OBJECTIVE
To apply and compare magnetic resonance imaging (MRI) metal artifact reducing sequences (MARS) including subtraction imaging after contrast application in patients with metal-on-metal (MoM) hip prostheses, investigate the prevalence and characteristics of periprosthetic abnormalities, as well as their relation with pain and risk factors.


METHODS
Fifty-two MoM prostheses (35 cases with pain and or risk factors, and 17 controls) in 47 patients were examined in a 1.5-T MR scanner using MARS: turbo spin echo (TSE) with high readout bandwidth with and without view angle tilting (VAT), TSE with VAT and slice encoding for metal artifact correction (SEMAC), short tau inversion recovery (STIR) with matched RF pulses, and post-contrast imaging. The relations of MRI findings to pain and risk factors were analyzed and in five revised hips findings from operation, histology, and MRI were compared.


RESULTS
TSE VAT detected the highest number of osteolyses. Soft tissue mass, effusion, and capsular thickening were common, whereas osteolysis in acetabulum and femur were less frequent. Contrast enhancement occurred in bone, synovia, joint capsule, and the periphery of soft tissue mass. There was no significant relation between MRI findings and pain or risk factors.


CONCLUSIONS
MARS and gadolinium subtraction imaging are useful for evaluation of complications to MoM prosthesis. TSE VAT had the highest sensitivity for osteolysis. Contrast enhancement might indicate activation of aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL). Pain, small head, or steep prosthesis inclination angle are not useful predictors of periprosthetic abnormalities, and wide indications for MR follow-up are warranted.
Department of Radiology, Lund University, Skåne University Hospital, Inga Marie Nilssonsgata 49, 20502, Malmö, Sweden, gunilla.muller@med.lu.se.
Gunilla M
GM
Müller
Sven
S
Månsson
Markus F
MF
Müller
Thord
T
von Schewelov
Mathias
M
Nittka
Olle
O
Ekberg
Björn
B
Lundin
D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D016477:Artifacts; D016022:Case-Control Studies; D003287:Contrast Media; D004867:Equipment Design; D005260:Female; D005682:Gadolinium; D006621:Hip Joint / Q000473:pathology; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008670:Metals; D008875:Middle Aged; D015588:Observer Variation; D010014:Osteolysis / Q000175:diagnosis* / Q000209:etiology; D010146:Pain / Q000209:etiology; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013382:Subtraction Technique
D003287:Contrast Media; D008670:Metals; D005682:Gadolinium