The Study of the Validity and Reliability between Digital Radiographic Imaging Software and Manual Method in Measuring Cobb s Angle and Innominate Vertical Length

The purpose of this study was to assess the reliability of manual and digital methods in measuring Cobb s angle and Innominate vertical length. Fifteen chiropractic student observers measured the Cobb s angle and Innominate vertical length using both the digital and the film manual methods. Ten whole spine AP X-ray images from idiopathic scoliosis were chosen without predilection for magnitude of the curvature, gender, age or location. Each image was examined 3 times at a minimum interval of 1 day between repeated measurements, by each observer. For the digital measurement, ‘X-maruViewerV1 for chiropractic’ which specific software was developed to digitally reproduce the chiropractic assessment was used, and for the manual measurement, protractor, Gonstead ruler were used. For reliability of inter and intraobserver correlation coefficients(ICC) were calculated. Standard Error of Measurements(SEM) within and between observers measurements was analyzed. The validity of manual and digital measurement was assessed by Student t-test. Statistical indexes of Student t-test, intra and interobserver did not reveal statistically significant differences between manual and digital measurements. This indicates that the statistical indexes calculated for the two methods had similar results. Previous study showed that Cobb s angle measurements may be reproduced in the computer as reliably as with the film manual method, in similar conditions to those found in clinical practice. The result of this study confirms the reliability of digital radiographic imaging software which can be used in chiropractic studying system as well as clinical practice.