COMPARISON OF THE PRECISION OF 2 VERTEBRAL MORPHOMETRY PROGRAMS FOR THE LUNAR EXPERT-XL IMAGING DENSITOMETER

Comparative precision tests of the vertebral height measurement functi on of the Aberdeen Vertebral Morphometry System (AVMS) software and Lu nar EXPERT-XL software were undertaken using four vertebrae from the s ame lateral spine dual energy X-ray absorptiometry (DXA) image of the same subject (male, 67 years). Two of the vertebrae were abnormal and two were normal. Three observers inexperienced in morphometry and one experienced observer took part in the study, Repeatability was obtaine d from IO sequential measurements of the posterior, middle and anterio r heights at the same sitting by the same observer. Intraobserver repr oducibility compared the means of one set of measurements for all vert ebrae with another taken 1 week later. Interobserver reproducibility c ompared the means of one set of measurements for all vertebrae from an experienced and an inexperienced observer, and from two inexperienced observers. The AVMS software had significantly higher (p<0.05) repeat ability (mean coefficient of variability, CV = 3.5%) than the Lunar so ftware (mean CV = 5%), significantly higher (p < 0.01) intraobserver r eproducibility (mean CV = 4.6%) than the Lunar software (mean CV = 8.5 %), and significantly higher (p < 0.05) interobserver reproducibility (mean CV = 4.7%) than the Lunar software (mean CV = 7.5%). In conclusi on, the new AVMS method possessed higher precision when measuring both abnormal and normal vertebrae and when used by both experienced and i nexperienced observers.