Spinal deformity & inflammatory spine: a free FRCS (Tr & Orth) Section 1 question

This is presumed idiopathic scoliosis with atypical features that suggest a neural axis abnormality such as a Chiari I malformation with a syrinx, a tethered cord or an intraspinal tumour. Typical adolescent idiopathic curves are right thoracic in a girl, painless and neurologically normal. Indications for MRI of the whole neural axis include a left thoracic curve, an asymmetrical abdominal reflex, other neurological signs, significant pain, rapid progression, onset before 10 years of age, a short angular curve, foot deformity and apical hyperkyphosis. Bracing or observation before imaging would miss a treatable cause whose treatment may halt the curve. CT shows bone but not the cord, and evoked potentials do not provide a diagnosis. Reference: Miller's Review of Orthopaedics 8e.