Objectives Paediatric lumbosacral lipomas are commonly assessed by whole spine MRI, which is costly, time consuming and reduces imaging detail at the region of interest. This study evaluates the utility of whole spine vs local spine MRI in paediatric lumbosacral lipoma (LSL).

Design Single centre, retrospective, radiological review.

Subjects 119 patients (77F:46M) aged 0.8 years (0.2–3.9) (median ±IQR) with complex LSL who had whole spine MRI between 2001–2017.

Methods Lumbosacral lipomas were identified from a prospectively collected database. Cases where whole spine MRI was available were included. Type of lipoma and any associated spinal anomalies were recorded.

Results 347 patients had LSL, of which 119 (34%) patients had whole spine MRI. 3% were excluded due diagnosis of fatty filum terminale. 13% scans were unavailable. 119 patients were studied: 77F:46M aged 0.8 years at scan. Type of LML: transitional 36%; caudal 18%; dorsal 19%; unclassified 26%. Additional imaging abnormalities included: syrinx 18%; Chiari 1%; dermal sinus tract 13%; vertebral segmentation 13%; other 2%. None were associated with clinical symptoms nor required surgical treatment. Investigating the cost-benefit analysis of modality, lumbar spine required less MR time and cost less (40 vs 20 mins; £228.69 vs £282.39).

Conclusions The low incidence of clinically relevant secondary lesions suggests that lumbosacral MRI only is necessary in the assessment of LSL. Imaging quality of the ROI can be optimised and MRI time and costs reduced.