Whole spine MRI is not required in investigating uncomplicated paediatric lumbosacral lipoma. A retrospective single-institution review

Abstract

Purpose Lumbosacral lipoma (LSL) is a severe occult spinal dysraphism, frequently associated with neurological, urological and orthopaedic complications. Whole spine imaging is typically performed to identify concomitant, but spatially separate, congenital anomalies. Our hypothesis: the incidence of additional, clinically significant abnormalities of the neuraxis is low; thus, imaging should be optimised at the lumbosacral region. We aim to assess the prevalence and relevance of LSL-associated lesions. Method A single-centre, retrospective, radiological review using a prospectively maintained operative database. Inclusion criteria: children (< 16 years) with confirmed diagnosis of LSL and received whole spine MRI. Fatty filum, syndromic cases and cutaneous stigmata above lesion level were excluded. Data was extracted from radiological imaging, reports and clinical correspondence. Results One hundred twelve patients (40:72, M:F) aged 0.5 years (0.2–2.7) (median ± IQR) with LSL had whole spine MRI between 2001 and 2017. Classification of LSL: transitional 48 (43%); dorsal 30 (27%); caudal 28 (25%) and chaotic 6 (5%). Additional anomalies included syringohydromyelia 44 (39%), subcutaneous tract 19 (17%), abnormal vertebral segmentation 18 (16%), dermoid cyst 1 and 1 Chiari I deformity. There were no Chiari II malformations. No child required surgery for an associated lesion. Binary logistic regression revealed no factors associated with predicting secondary lesions. Conclusions In congenital LSL, additional anomalies of the neuraxis are typically loco-regional rather than pan-CNS and additional lesions are rarely clinically significant. The loco-regional distribution of anomalies suggests that only lumbosacral spinal imaging is required in the initial evaluation of LSL. Such a policy would lessen the anaesthetic/sedation time for children and reduce imaging cost per patient. MRI protocols could be refined to optimise imaging quality at the region of interest.

International Consensus Statement on the Radiologic Evaluation of Dysraphic Malformations of the Spine and Spinal Cord

“…In isolate, closed dysraphic states there is limited clinical utility in imaging 10 beyond the lumbosacral region. (28) Optimized MRI protocolling is crucial to maximize diagnostic yield and reduce scanning time, thereby limiting the necessity or duration of sedation. We recommend a combination of simple and advanced sequences to image both the whole spine including dedicated, high-resolution imaging of the area of the suspected abnormality.…”