Perthes' Disease Clinical Trial
Official title:
The Effect of Perthes' Disease on Hip Cartilage
The purpose of this study is to determine whether Perthes' disease has caused detectable hip cartilage damage in young people who have reached the healed stage of the disease.
We will recruit 20 subjects from our healed Perthes' population. We will use dGEMRIC imaging
to identify regions of cartilage degeneration in the femur and acetabulum. Both hips will be
imaged so that we can use the unaffected side as a control. We will apply dGEMRIC imaging,
which allows the composition of cartilage (specifically, the concentration of
glycosaminoglycans [GAGs], important structural proteins in the cartilage) to be assessed.
The MRI protocol consists of intravenous injection of 0.4 ml/kg dose of gadopentetate
dimeglumine 2- [Gd-DTPA2-] contrast agent (Magnevist, Bayer) 90 minutes prior to imaging. Due
to the need to image within a relatively narrow window of time, each hip of each subject must
be imaged on separate days. The subject will be asked to walk for 10 minutes after receiving
the contrast agent injection to facilitate equilibration of contrast agent into the hip
joint.
The scans will be performed at UBC's High Field Imaging Centre on the 3T Phillips Intera
scanner. Dr. Wilson has access to this scanner for his research. The scanning protocol is as
follows: 3D IR-TFE sequence with TR/TE/Flip of 4.7 ms/1.6 ms/30 o and seven inversion times;
1600, 1200, 800, 400, 200, 300, and 100 ms. In-plane resolution is 0.7 mm with a slice
thickness of 3 mm. Total imaging time is approximately 1 hour (at each visit). The T1
calculated image will be obtained using validated, custom written software (IGOR). The
resulting image provides a map approximating glycosaminoglycan concentration and,
consequently, cartilage degeneration.
The MRI will not be done under sedation. MRIs are performed under sedation at BCCH for
children under age seven. Subjects in this study will be between the ages of 7 and 18. The
contrast agent, Gd-DTPA2- is routinely used in children in the clinical setting.
Radiographs used for comparison are obtained as part of standard of care follow-up protocol.
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