Accurate measurement of bone mineral density using clinical CT imaging with single energy beam spectral intensity correction.
Although dual-energy X-ray absorptiometry (DXA) offers an effective measurement of bone mineral density, it only provides a 2-D projected measurement of the bone mineral density. Clinical computed tomography (CT) imaging will have to be employed for measurement of 3-D bone mineral density. The typical dual energy process requires precise measurement of the beam spectral intensity at the 80 kVp and 120 kVp settings. However, this is not used clinically because of the extra radiation dosage and sophisticated hardware setup. We propose an accurate and fast approach to measure bone material properties with single energy scans. Beam hardening artifacts are eliminated by incorporating the polychromatic characteristics of the X-ray beam into the reconstruction process. Bone mineral measurement from single energy CT correction is compared with that of dual energy correction and the commonly used DXA. Experimental results show that single energy correction is compatible with dual energy CT correction in eliminating beam hardening artifacts and producing an accurate measurement of bone mineral density. We can then estimate Young's modulus, yield stress, yield strain and ultimate tensile stress of the bone, which are important data for patient specific therapy planning.
Department of Electrical and Computer Engineering, National University of Singapore, 117576 Singapore. jzhang@i2r.a-star.edu.sg
Jing
J
Zhang
Chye-Hwang
CH
Yan
Chee-Kong
CK
Chui
S H
SH
Ong
D015502:Absorptiometry, Photon / Q000379:methods*; D000465:Algorithms; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000502:physiology*; D006801:Humans; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*