Understanding Early Hemophilic Arthropathy in Children and Adolescents Through MRI T₂ Mapping

Persons with hemophilia experience hemarthrosis, which can lead to cartilage degeneration, causing physical impairment. MRI T₂ mapping has the potential to be used as a tool to evaluate early arthropathic changes and cartilage degeneration in patients with hemophilia.

To assess the value of MRI-T₂ mapping as a tool for investigating the cartilage status of children and adolescents with hemophilic arthropathy.

Prospective, cross-sectional.

Twenty-eight boys with hemophilia (aged 5-17 years) and 23 healthy boys (aged 7-17 years).

A multiecho spin-echo T₂ -weighted gradient echo sequence was used on a 3.0T magnet.

MRI-T₂ maps of ankle (tibia-talus) (n = 19) or knee (femur-tibia) (n = 9) cartilage were assessed in hemophilia and healthy groups. An anatomically-based MRI score was also assigned to each ankle/knee.

Pearson's correlation coefficient (r), linear regression, intraclass correlation coefficient (ICC), and analysis of variance (ANOVA) test.

Negative associations between age and ankle/knee cartilage T₂ relaxation times were found in hemophilia (r = -0.72 [P = 0.03] to -0.55 [P = 0.01]) and healthy (r = -0.84 [P < 0.001] to -0.55 [P = 0.20]) groups. There were nonsignificant associations between ankle cartilage T₂ relaxation times and MRI scores (r = -0.15 [P = 0.54] to 0.31 [P = 0.19]).

Results of this clinical investigation emphasize the potential importance of MRI-T₂ maps as a tool to understand the functional status of cartilage in children and adolescents with hemophilic arthropathy, while holding promise for the detection of early cartilage degeneration prior to macroscopic characterization by conventional MRI. MRI-T₂ mapping may provide novel information that is not reflected in the anatomically-based MRI scoring system.

3 TECHNICAL EFFICACY STAGE: 2.