Enhance + applies stronger local contrast and edge sharpening automatically. Auto enhance offers a milder level. Both process the original pixels without stacking filters. It does not identify landmarks or recover missing detail. Enhancement can accentuate noise or create edge artifacts; compare with Original when placing points. Both views use identical image coordinates.
For pediatric AP pelvic radiographs with identifiable triradiate cartilage. Points 1 and 2 mark the most inferior bony iliac margins at the triradiate cartilages. Points 3 and 4 mark the lateral bony acetabular rims, not the lateral sourcil edges.
The line between points 1 and 2 is Hilgenreiner’s line. Each angle uses its outward extension and the line from that hip’s triradiate landmark to its bony rim.
Keep superior at the top of the image. Baseline alignment accounts for in-plane obliquity, not pelvic rotation, tilt, perspective distortion, or stretched images. Negative angles are preserved and flagged for review. Display precision is 0.1°, not an accuracy guarantee. Reference comparisons use the supplied Novais et al. Table 1 means and SDs for sex and patient side. Limits are mean ± 2SD, inclusive; comparison uses the unrounded angle. These are grouped statistical ranges, not diagnosis or treatment thresholds and not the study’s fitted percentile curves. The app assigns each exact age boundary to the older group (e.g. 6 months uses 0.5 to <1 year); it does not interpolate. Ages 14 years or older have no range. Age is calculated in completed calendar months from DOB to exam date, which defaults to today. Six-digit DOB uses MMDDYY with year 20YY; eight-digit MMDDYYYY and MM/DD/YYYY are also accepted. Invalid dates or DOB after exam date have no classification. Month-end anniversaries use the last valid day. DOB and sex clear when a new image opens.
Novais et al. J Pediatr Orthop, 2018, Table 1 ↗
Maddock et al. J Child Orthop, 2019 ↗First mark T12-L1 (drag the marker to adjust). Suggested regions use endplate midpoint positions above, across, or below this boundary. Multiple thoracic curves are labeled from top to bottom: upper/lower for two, upper/mid/lower for three. This is a positional suggestion, not vertebral or apex detection; choose upper/mid/lower thoracic or correct any suggestion using the region selector. Draw independent endplate lines on a frontal spine radiograph, using two points per line. Select the appropriate endplates for each curve; shared middle lines are used in both neighboring measurements.
Convexity is inferred from the signed change in endplate direction, assuming standard frontal display with patient right on image left. The direction selector can override a mirrored image or return to Auto. Parallel lines have no inferred convex side. The angle is calculated from the two endplate directions. Endpoint click order does not change it. Both directions are aligned across the chord joining their midpoints, allowing angles above 90° without folding to the acute supplement. Ambiguous or overlapping lines require new landmarks. Check the end vertebrae and angle construction, especially in severe deformity. No diagnosis, treatment threshold, or automatic vertebral selection is provided.
Images must retain their original proportions. Cobb angles are rounded upward to whole degrees for display and reporting; geometry retains full precision. Keep placing two endpoints per line to extend the connected measurements. Lines are ordered by their position in the image. Each neighboring pair produces an angle; dragging a shared line updates both neighboring angles.
Scoliosis Research Society: Cobb method ↗