Use of 1.5 Tesla and 3 Tesla MRI to Evaluate Femoral Head Reduction in Hip Dysplasia
ABSTRACT To date no comparison between 1.5 Tesla (T) and 3 T magnetic resonance imaging (MRI) scans have been performed in assessing hip reduction in patients with hip dysplasia. This study compares the use of these scans in assessing hip reduction.
A retrospective review of 1.5 T and 3 T postreduction pelvic MRIs in developmental dysplasia of the hip patients for scanner time, anesthesia requirement, and subjective image quality scores were performed. Intrareader and interreader agreement of state of hip reduction was assessed. A scoring system was used to objectively compare MRI sequences between the 1.5 T and 3 T scans.
Of the 37 MRI scans, scanner time and anesthetic requirement was not significantly different between 1.5 T and 3 T scans (P > 0.05). The 3 T scans showed slightly better image quality than 1.5 T scans (5.7 vs. 4.7), but not significant (P = 0.08). With regards to state of hip reduction, intrareader Cronbach α was 0.89 with 1.5 T and 0.98 with 3 T, whereas interreader agreement was 0.79 with 1.5 T and 0.95 with 3 T, revealing greater consistency with 3 T. Mean anatomic score comparison of hip anatomic markers show no overall statistical difference between fast hip protocol sequences (f = 1.113, sig = 0.346) or magnet strength (f = 3.817, sig = 0.053). Only the coronal T2W fast spin echo demonstrated a statistically higher score on the 3 T versus the 1.5 T (19.3 ± 9.3 vs. 12.2 ± 6.7) scanner.
Our study affirms that adequate images are obtainable with fast hip MRI without additional anesthesia. Good agreement was reached on image quality and hip state of reduction between readers for 1.5 T and 3 T scans, with more consistency with 3 T.
Diagnostic Level II.
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ABSTRACT: The purpose of this study was to investigate the development of the osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) using MRI. The OAI and CAI were measured on the coronal MR images of the hip in 81 children with developmental dysplasia of the hip (DDH), with a mean age of 19.6 months (3 to 70), and 241 normal control children with a mean age of 5.1 years (1 month to 12.5 years). Additionally the developmental patterns of the OAI and CAI in normal children were determined by age-based cross-sectional analysis. Unlike the OAI, the normal CAI decreased rapidly from a mean of 10.17° (sd 1.60) to a mean of 8.25° (sd 1.90) within the first two years of life, and then remained constant at a mean of 8.04° (sd 1.65) until adolescence. Although no difference in OAI was found between the uninvolved hips in children with unilateral DDH and normal hips (p = 0.639), the CAI was significantly different between them both (p < 0.001). The normal CAI has fully formed at birth, and is maintained constantly throughout childhood. The CAI in the unaffected hips in children with unilateral DDH is also mildly dysplastic.The Bone & Joint Journal 12/2012; 94(12):1625-31. DOI:10.1302/0301-620X.94B12.29958 · 2.80 Impact Factor
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ABSTRACT: Two-dimensional multiple-echo data image combination (MEDIC) images, as well as conventional T1-weighted and T2-weighted images, were obtained for 38 infants with developmental dysplasia of the hip. We retrospectively reviewed these images to evaluate subjective image quality and femoral head-to-ischium contrast. MEDIC images were considered to be of high quality compared with the conventional T1-weighted (P<0.0001) and T2-weighted images (P<0.05), as well as have a higher contrast than conventional T1-weighted and T2-weighted images (P<0.001, respectively). In conclusion, MEDIC images provide diagnostic improvement in studies on developmental dysplasia of the hip.Journal of pediatric orthopaedics. Part B / European Paediatric Orthopaedic Society, Pediatric Orthopaedic Society of North America 09/2013; DOI:10.1097/BPB.0000000000000001 · 0.66 Impact Factor