Comparison of radiographic texture analysis from computed radiography and bone densitometry systems

• Published in: Medical physics (Lancaster) Vol. 31; no. 4; pp. 882 - 891
• Main Authors: Wilkie, Joel R., Giger, Maryellen L., Chinander, Michael R., Vokes, Tamara J., Li, Hui, Dixon, Larry, Jaros, Vit
• Format: Journal Article
• Language: English
• Published: United States American Association of Physicists in Medicine 01-04-2004
• Subjects: Absorptiometry, Photon - instrumentation; Absorptiometry, Photon - methods; Aged; Aged, 80 and over; bone; Bone densitometry; Bone Density; Calcaneus - diagnostic imaging; Computed radiography; densitometry; Density measurement; diagnostic radiography; Electric measurements; Equipment Failure Analysis; Female; Frequency measurement; Humans; Mass measurement; medical diagnostic computing; medical image processing; Medical imaging; Medical X‐ray imaging; Middle Aged; Osteoporosis - diagnosis; Osteoporosis - diagnostic imaging; Radiographic Image Enhancement - instrumentation; Radiographic Image Enhancement - methods; Radiographic Image Interpretation, Computer-Assisted - instrumentation; Radiographic Image Interpretation, Computer-Assisted - methods; Radiography; Reproducibility of Results; Sensitivity and Specificity; texture; Tomography, X-Ray Computed - instrumentation; Tomography, X-Ray Computed - methods; X‐ray absorption; X‐ray imaging
• ISSN: 0094-2405; 2473-4209
• DOI: 10.1118/1.1650529

Osteoporosis is a disease that results in an increased risk of bone fracture due to a loss of bone mass and deterioration of bone structure. Bone mineral density (BMD) provides a measure of bone mass and is frequently measured by bone densitometry systems to diagnose osteoporosis. In addition, computerized radiographic texture analysis (RTA) is currently being investigated as a measure of bone structure and as an additional diagnostic predictor of osteoporosis. In this study, we assessed the ability of a peripheral bone densitometry (PD) system to yield images useful for RTA. The benefit of such a system is that it measures BMD by dual-energy x-ray absorptiometry and therefore provides high- and low-energy digital radiographic images. The bone densitometry system investigated was the GE/Lunar PIXI, which provides
512×512
digital images of the heel or forearm (0.2 mm pixels). We compared texture features of heel images obtained with this PD system to those obtained on a Fuji computed radiography (CR) system (0.1 mm pixels). Fourier and fractal-based texture features of images from 24 subjects who had both CR and BMD exams were calculated, and correlation between the two systems was analyzed. Fourier-based texture features characterize the magnitude, frequency content, and orientation of the trabecular bone pattern. Good correlation was found between the two modalities for the first moment (FMP) with
r=0.71
(p 
value
<0.0001)
and for minimum FMP with
r=0.52
(p 
value
=0.008).
Root-mean-square (RMS) did not correlate with
r=0.31
(p 
value
>0.05),
while the standard deviation of the RMS did correlate with
r=0.79
(p 
value
<0.0001).
Good correlation was also found between the two modalities for the fractal-based texture features with
r=0.79
(p 
value
<0.0001)
for the global Minkowski dimension and
r=0.63
(p 
value
=0.0007)
for the fractal dimension from a box counting method. The PD system therefore may have the potential for yielding heel images suitable for RTA.