Fig. 4

(a) TK/LL angle measured on the sagittal X-ray image (b) Eight sagittal plane images from four ultrasound scans, each scan yielding the left and right vertebral lamina Yellow numbers indicate the USLA for each image, with the final USLA angle representing the average of the automatically measured left and right sagittal lamina USLA. Red line segments denote the USLA of the thoracic and lumbar vertebrae. LL: lumbar lordosis, TK: thoracic kyphosis, USLA: ultrasound lamina angle, VPI: volume projection image.