Abstract
Background Information on embryological hip development has been obtained from post mortem examination (1). There is less information on normal fetal hip (2). Magnetic resonance imaging (MRI) allows development to be followed in the healthy baby.
Aim To assess the value of MRI of the foetus and neonate to provide information on normal and abnormal hip development.
To establish normal patterns of hip development.
To obtain charts that could be used to detect abnormality earlier.
There are three aspects to this study:
-
Validation – analysing MRI scans of babies hips prior to post mortem (the gold standard) would verify MRI as a valid tool for such studies.
-
Similarly for a) fetuses in utero b) pre and term babies.
Patient selection 30 patients for each aspect of this pilot study, 90 in total (3).
For the initial validation process, parents who had consented to post mortem were asked to consider additionally an MR scan of their neonate’s hips, a total of 30 cases.
Method MR images in axail and coronal planes were obtained using a high resolution T2 weighted sequences (4).
Measurements were made, by two independent observers, of the width and depth of the acetabulum and the radius & diameter of the femoral head, volume and area were calculated. Inter-observer variation was assessed.
Results The babies ranged in gestation from 17 – 42 weeks
With the exception of the acetabular width each dimension showed little development until week 20 when the line of growth rose exponentially. The acetabular width showed only a slow rate of growth despite the changes seen in the femoral head. Levels of observer agreement were high (ICCs 95% = 0.98) for all but depth (ICCs 95% = 0.86). The measurements for all dimensions were in line with previous post mortem studies.
Conclusion MRI is a valid and acceptable alternative to post mortem in the assessment of hip development eventually allowing early detection of abnormal hip development.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
