Coronary calcium scoring using virtual non-contrast reconstructions on a dual-layer spectral CT system: Feasibility in the clinical practice. Issue 159 (February 2023)

• Record Type: Journal Article
• Authors: Langenbach, I.L.; Wienemann, H.; Klein, K.; Scholtz, J.E.; Pennig, L.; Langzam, E.; Pahn, G.; Holz, J.A.; Maintz, D.; Naehle, C.P.; Langenbach, M.C.
• Is Part Of: European journal of radiology. Issue 159(2023)
• Publication Date: 2023-02
• Subjects: Tomography -- X-ray computed -- Coronary artery disease -- Cardiac imaging techniques -- Contrast media -- Radiation dosage; CAC coronary artery calcium -- CAD coronary artery disease -- CAC-DRS Coronary Artery Calcium Data and Reporting System -- CACS coronary artery calcium scoring -- cCTA coronary computed tomography angiography -- DLP dose-length-product -- HU Hounsfield Units -- ICC intra-class correlation coefficient -- PACS picture archiving and communication system -- SDCT spectral detector CT -- TNC true non-contrast -- VNC virtual non-contrast; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2022.110681
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: VNC reconstructions of cCTA allow assessment of CACS without an additional unenhanced CT scan for calcium scoring. This algorithm enables the application of VNC CACS in the clinical routine with a significant radiation dose reduction. A correction factor is required to achieve a good agreement with the TNC standard technique. Abstract: Purpose: To evaluate the clinical applicability of a prototype virtual non-contrast (VNC) reconstruction algorithm based on coronary CT angiography (cCTA) to assess calcified coronary plaques by calcium scoring (CACS). Methods: Eighty consecutive patients suspected of coronary artery disease were retrospectively included. All patients underwent a cardiac CT using a dual-layer spectral-detector CT system. The standardized acquisition protocol included unenhanced CACS and cCTA. Datasets were acquired using 120 keV. VNC-reconstructions were calculated from the cCTA images at 2.5 mm (VNC group 1), 2.5 of 0.9 mm (group 2), and 0.9 mm (group 3) slice thickness. We compared the Agatston score and Coronary Artery Calcium Data and Reporting System (CAC-DRS) of all VNC reconstructions with the true non-contrast (TNC)-dataset as the gold standard. Results: In total, 73 patients were evaluated. Fifty patients (68.5 %) had a CACS > 0 based on TNC. We found a significant difference in the Agatston score comparing all VNC-reconstructions (1: 1.35, 2: 3.7, 3: 10.4) with the TNC dataset (3.8) (p < 0.001). Correlation analysis of the datasets showed an excellent correlation of the TNC results with the different VNC-reconstructions (r = 0.904–0.974, p < 0.001) with a slope of 1.89–2.53. Mean differences and limits of agreement by Bland–Altman analysis between TNC and group 1 were 83 and −196 to 362, respectively. By using the VNC-reconstructions, in group 1 23 patients (31.5 %), in group 2 10 (13.7 %), and in group 3 23 (31.5 %) were reclassified according to CAC-DRS compared to TNC. Classification according to CAC-DRS revealed a significant difference between TNC and group 1 (p = 0.024) and no significance compared to groups 2 and 3 (p = 0.670 and 0.273). Conclusion: The investigated VNC reconstruction algorithm of routine cCTA allows the detection and evaluation of coronary calcium burden without the requirement for an additional acquisition of an unenhanced CT scan for CACS and, therefore, a reduction of radiation exposure.