Photon-counting CT Spectral Localizer Radiographs for Lumbar Areal Bone Mineral Density Quantification: A Clinical Study on Accuracy, Reliability, and Diagnostic Performance for Osteoporosis

Shanshui Zhou; Shutian Zhao; Rui Chang; Haipeng Dong; Lianjun Du; Yong Lu; Qiang Zhang; Yin Zhang; Zhe Chen; Tristan Nowak; Zhihan Xu; Le Qin; Fuhua Yan

doi:10.1016/j.acra.2025.01.038

Photon-counting CT Spectral Localizer Radiographs for Lumbar Areal Bone Mineral Density Quantification: A Clinical Study on Accuracy, Reliability, and Diagnostic Performance for Osteoporosis

Acad Radiol. 2025 Jun;32(6):3540-3551. doi: 10.1016/j.acra.2025.01.038. Epub 2025 Feb 11.

Authors

Shanshui Zhou¹, Shutian Zhao¹, Rui Chang², Haipeng Dong², Lianjun Du², Yong Lu², Qiang Zhang³, Yin Zhang³, Zhe Chen³, Tristan Nowak⁴, Zhihan Xu⁵, Le Qin⁶, Fuhua Yan¹

Affiliations

¹ Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China (S.Z., S.Z., R.C., H.D., L.D., Y.L., L.Q., F.Y.); Faculty of Medical Imaging Technology, College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, No. 150 Ruijin Er Road, Shanghai 200025, China (S.Z., S.Z., F.Y.).
² Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China (S.Z., S.Z., R.C., H.D., L.D., Y.L., L.Q., F.Y.).
³ Department of Orthopedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China (Q.Z., Y.Z., Z.C.).
⁴ Siemens Healthineers AG, Siemensstr. 3, Forchheim 91301, Germany (T.N.).
⁵ CT Collaboration, Siemens Healthineers, Shanghai, China (Z.X.).
⁶ Department of Radiology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197 Ruijin Er Road, Shanghai 200025, China (S.Z., S.Z., R.C., H.D., L.D., Y.L., L.Q., F.Y.). Electronic address: ql11880@rjh.com.cn.

PMID: 39934075
DOI: 10.1016/j.acra.2025.01.038

Abstract

Rationale and objectives: To explore the accuracy, reliability, and diagnostic performance of photon-counting CT (PCCT) spectral localizer radiographs (SLRs) for quantifying lumbar areal bone mineral density (BMD) and detecting osteoporosis (T-score ≤-2.5).

Materials and methods: This prospective study recruited consecutive participants from April to July 2024. Participants each underwent a dual-energy X-ray absorptiometry (DXA) examination serving as the gold-standard reference for aBMD (aBMD_DXA) and a PCCT scan to obtain SLR. The SLRs were reconstructed into hydroxyapatite (HA) and water maps. Lumbar vertebrae (L1 to L4) and soft tissue were blindly and semiautomatically segmented on HA and water maps to calculate aBMD_SLR. The agreement and relative absolute error (RAE) between aBMD_SLR and aBMD_DXA were calculated. Factors that might influence the RAE were evaluated. Using DXA results as the reference, the diagnostic performance of PCCT-SLRs for osteoporosis was assessed.

Results: A total of 159 participants (88 females) with a median age of 66 years (interquartile range [IQR], 55-72 years) were included. The median (IQR) aBMD_DXA and aBMD_SLR values were 1.095 (0.936-1.261) g/cm² and 1.086 (0.932-1.255) g/cm², respectively. There was excellent agreement between the two methods (mean bias=-0.57%). The median (IQR) RAE was 2.65% (1.23-4.07%). The RAE was unaffected by age, body mass index, aBMD, sex, tube voltage, or tube current. The sensitivity and specificity of PCCT-SLRs for osteoporosis diagnosis were 92.31% (12/13) and 98.63% (144/146), respectively.

Conclusion: The PCCT-SLR is an accurate and reliable approach for lumbar aBMD quantification in humans, with high diagnostic performance for osteoporosis.

Keywords: Opportunistic osteoporosis screening; Photon-counting CT; bone mineral density; spectral imaging.

MeSH terms

Absorptiometry, Photon / methods
Aged
Bone Density*
Female
Humans
Lumbar Vertebrae* / diagnostic imaging
Male
Middle Aged
Osteoporosis* / diagnostic imaging
Prospective Studies
Reproducibility of Results
Sensitivity and Specificity
Tomography, X-Ray Computed* / methods