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Updated: Jun 27, 2026
Cortical Bone Assessment Using Ultrasonic Guided Waves: A Reproducibility Study in a Healthy Population
Published on: January 31, 2025
Feasibility of opportunistic peripheral bone mineral density and structural quantification using an ultra-low dose
Malakeh Malekzadeh1,2, Joyce H Keyak3, Nazanin Mobini2,4
1Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
None:
Quantitative computed tomography (QCT) enables accurate assessment of volumetric bone mineral density (vBMD) and bone structure. Peripheral QCT (pQCT) and high-resolution pQCT (HR-pQCT) have been proposed as lower-dose alternatives to conventional QCT; however, their limited availability restricts widespread clinical and research use. To investigate the feasibility of using ultra-low-dose multi-detector computed tomography (MDCT) with a hybrid iterative reconstruction (HIR) algorithm for quantifying tibial vBMD, using synchronous liquid and solid calibration phantoms. Fifty volunteers (28 women and 22 men; age range: 30-60 yr;T-score ⩾ -1) without metabolic bone disorders, were scanned using a Philips-Brilliance MDCT scanner. To minimize radiation exposure, vBMD was quantified at the 38% distal tibial site using either a liquid calibration phantom (50, 100, and 200 mg cm-3dipotassium hydrogen phosphate [K2HPO4]) or a solid calibration phantom (50, 100, and 250 mg cm-3calcium hydroxyapatite [CHA]). A cross-calibration equation was applied to derive equivalent vBMD values between phantom types. Cortical bone structure was evaluated using a semi-automated segmentation approach. Following cross-calibration, BMDK2HPO4 = 1.34 BMDCHA + 13.43, mean cortical vBMD values were 1188.07 ± 29.38 mg cm-3(CHA) and 1600.92 ± 39.51 mg cm-3(K2HPO4). The CHA-based cortical vBMD values were consistent with solid-based pCT measurements reported in the literature. Mean cortical thickness was approximately 5 mm. The estimated effective radiation dose is approximately 10µSv, corresponding to daily background radiation levels. This preliminary study demonstrates the feasibility of using HIR-based ultra-low-dose MDCT for peripheral tibial vBMD and structural assessment at the 38% distal site. This approach offers a promising opportunistic alternative in clinical and research settings where pQCT or HR-pQCT systems are unavailable.
