Impact of Different Collimations on Bone Mineral
Density Measurements Using Dual-Energy
CT: A Phantom Study

Ning Yao; WanjiangYu; Yuting Shi; Hang Ye; Yujiao Wang

doi:10.26717/BJSTR.2022.47.007451

Research ArticleOpen Access

Impact of Different Collimations on Bone Mineral Density Measurements Using Dual-Energy CT: A Phantom Study

Volume 47 - Issue 1

Ning Yao¹, Yuting Shi², Hang Ye³, Yujiao Wang³ and WanjiangYu¹*

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- ¹Department of Medical Imaging, Qingdao Municipal Hospital, Qingdao, China
- ²Department of Medical Imaging, Weifang Medical University, Weifang, China
- ³Department of Medical Imaging, Dalian Medical University, Dalian, China

Received: November 02, 2022; Published: November 11, 2022

DOI: 10.26717/BJSTR.2022.47.007451

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Abstract

Purpose: This study aimed to assess the influence of different collimations on bone mineral density (BMD) measurements by Dual-energy computed tomography (DECT) using the European spine phantom (ESP).

Methods: To simulating abdominal total adipose tissue (TAT) of the patients as normal, overweight and obese, ESP was wrapped by fresh subcutaneous fat from pigs of 200cm²,320cm2 and 400cm2, respectively. The ESP was scanned by DECT with two kinds of collimations (group 40 (640.625mm) and group 80 (1280.625mm), respectively), and CTDI was recorded. The relative measurement error (RME, %) and the root mean square error (RMSE) of HAP (water) values were calculated to assess the accuracy by paired t-test. In addition, correlation and agreement analyses were performed using Pearson correlation, linear regression, and Bland-Altman plots.

Results: When TAT was 200cm², HAP values between two groups were significantly different in L1(P<0.01) and L2(P<0.0001), except for L3. For L1 and L2, RMEs and RMSEs in group 40 were obviously lower than those in group 80. When TAT was 320cm2 and 420cm2, there were no statistically significant differences for these values between the two groups. There was good correlation and agreement between the measurements of two collimations. The values of CTDI were 9.09mGy and 8.83mGy for group 40 and 80, respectively.

Conclusions: For the patients as normal, especially with bone loss and osteoporosis, 40mm-collimation shows higher accuracy than 80mm-collimation on BMD measurements by DECT. For the overweight and obese patients, there was no significant difference between the two collimations, and 80mm-collimation is recommended to reduce the radiation dose.

Keywords: Dual-Energy Computed Tomography; Collimation; Phantom; Bone Mineral Density; Osteoporosis

Abbrevations: DECT: Dual-Energy Computed Tomography; ESP: The European Spine Phantom; BMD: Bone Mineral Density; ASiR-V: Adaptive Statistical Iterative Reconstruction-V; CTDI: Computed Tomography Dose Index