Reliability of an image analysis system for quantifying the radiographic trabecular pattern

Abstract

A reliability evaluation technique was used to examine the reliability of an image analysis system of the trabecular pattern and to determine the contribution of three possible sources of error variance. Two series of radiographs were taken of 14 lumbar vertebral slices (28 radiographs). Every radiograph was placed on a viewing box for digitization four times by a single operator (112 positions of radiographs) and from every position of a radiograph an area of 15 mm x 15 mm was digitized twice (224 samples for analysis). Ten geometrical characteristics of the trabecular pattern were studied and its orientation was analyzed in 12 directions. Reliability was determined by calculating Cronbach's alpha. This design enabled dividing the measurement error (1-alpha) into fractions associated with the X-ray procedure, the operator and the system. Using this reliability evaluation technique, it was found that the orientation variables are more reliable than the geometric variables. It was found that effort to increase the reliability should be directed toward improving the technical procedure of this image analysis system. Also, repeated measurements will increase the reliability. The number of repeated measurements based on a desired reliability can be calculated. This procedure of evaluation gives the opportunity to select a source of error variance which have to be reduced to increase reliability most effectively.

Osteoporosis and the general dental practitioner: reliability of some digital dental radiological measures

“…For parameters 5-26 in Tables 1 and 2, two previous reports, one on radiographs of the hip, and the other on radiographs of vertebral slices, list the values of Cronbach's a (37,41). These values have been copied to the two columns of Table 2 for Cronbach's a of the present study with the values of the previous reports shows that in most cases the values of the present study are higher.…”

“…A' is exceeded dramatically by the corresponding value of 0.99 referring to measurements in the front and ramus region of interest on the panoramic radiograph. It has been shown that repeated scanning of the same radiograph is the greatest source of noise, at least for the geometrical and topological parameters (41). The largest exception is the value for the orientation index LFD 0°of the upper inner region which is 0.07 less than the corresponding values in the column marked 'Ref.…”

“…However, both reference studies in Table 2 also include other sources of noise which explains why the reference values are less than the values of the present study. It has been shown that repeated scanning of the same radiograph is the greatest source of noise, at least for the geometrical and topological parameters (41).…”

Medieval trabecular bone architecture: The influence of age, sex, and lifestyle

“…Korstjens et al (1998) discussed similar difficulties with photographic images as compared to radiographic images. Digital image analysis of radiographic trabecular bone architecture was used in previous studies (Geraets et al, 1990;Grynpas et al, 1992Grynpas et al, , 1994, and the reliability of the technique is well-established (Korstjens et al, 1997). Radiographic images also capture trabecular structure throughout the entire section, and it was demonstrated that radiographic properties of trabecular bone architecture significantly correlate to biomechanical characteristics (Korstjens et al, 1998).…”

Computerized radiographic texture measures for characterizing bone strength: A simulated clinical setup using femoral neck specimens

“…[14][15][16] Previous studies investigating texture analysis methods in assessing bone structure and strength have used photomicrographs of trans-iliac bone biopsy specimens 17,18 or direct exposure radiographs of sagittal sections or cubic sections of lumbar vertebrae. 19,20 Another study performing texture analysis used lateral direct radiographs of lumbar vertebrae excised from cadavers. 21 While the results of these studies are promising, it is uncertain how these texture analysis methods would perform on in vivo radiographic images.…”