Regional lung function in scoliosis.

Radioactive xenon-133 was used to study the pattern of regional lung function in 35 scoliotic patients and 10 normal subjects in the sitting posture. The scoliotic curves were classified into three anatomical sites: high, if the apical vertebra was located between Thl and Th5; mid, between Th6 and ThlO; and low, between Thll and L4; only the primary curve was considered and in 70% of the patients this measured more than 600. The mean pattern of perfusion in patients with low and mid curves was not significantly different from that of the normals, nor was there any significant difference between the convex and concave lungs in these two groups. Patients with high curves showed three distinct patterns: (a) Subgroup 1 (2 patients): Perfusion was greatest at the apex and least at the base in the