ABSTRACT
BACKGROUND: The outcome measure of neonatal hip screening is usually the radiographic acetabular index. OBJECTIVE: To assess the feasibility of magnetic resonance imaging (MRI) without sedation and compare the utility of outcome parameters measured from MRI images. MATERIALS AND METHODS: The invitation for MRI scanning at 5 years of age was incorporated into follow-up for babies who had more than one ultrasound examination during treatment or surveillance. RESULTS: Diagnostic images were obtained in 132 of 134 children. The mean osseous acetabular index (standard deviation [SD]) was 16.6 (3.3) degrees for the right hip and 17.8 (3.2) for the left; the values for the cartilaginous acetabular index were 3.1 (3) and 3.4 (3.2). The mean downslope of a tangent to the lateral bony acetabular roof was 10.4 (4.5) and 9.0 (4.3) with respect to Hilgenreiner's line and that of a line drawn through the apex to the margin of the acetabulum was 3.7 (4.6) and 3.9 (4.7). Intra- and interobserver variation was greater for measures specific to the lateral acetabular roof than for ossific and cartilaginous indices. There was significant negative correlation between the downslope of the tangent to the lateral roof index and the age at onset of treatment on both sides, but no significant correlation for ossific or cartilaginous acetabular indices or apex-marginal index. CONCLUSION: MRI without sedation at 5 years of age is feasible as an outcome measure for hip screening programmes. Parameters specific to the lateral acetabulum may better reflect acetabular sufficiency, despite having greater observer variation than cartilaginous and ossific acetabular indices.
Subject(s)
Acetabulum , Magnetic Resonance Imaging , Child , Infant , Infant, Newborn , Humans , Child, Preschool , Observer Variation , Acetabulum/pathology , Magnetic Resonance Imaging/methods , Treatment Outcome , Retrospective Studies , Hip JointABSTRACT
A soft-tissue aneurysmal bone cyst located on the lateral aspect of the left thigh of a 12-year-old girl is described. Conventional radiography of the thigh was normal. Sonography showed a hypoechoic mass with a feeding vessel and intralesional vascularity. On MRI, it was of predominantly soft-tissue signal intensity with intense enhancement following administration of i.v. contrast medium. Histopathological examination diagnosed the lesion as a soft-tissue aneurysmal bone cyst. This is the fourth paediatric case of this very rare benign tumour.
