Minimal dose CT for left ventricular ejection fraction and combination with chest-abdomen-pelvis CT

• Published in: European journal of radiology Open 2024-12, Vol.13, p.100583, Article 100583
• Main Authors: Kusk, Martin Weber, Hess, Søren, Gerke, Oke, Kristensen, Lone Deibjerg, Oxlund, Christina Stolzenburg, Ormstrup, Tina Elisabeth, Christiansen, Janus Mølgaard, Foley, Shane J.
• Format: Article
• Language: English
• Subjects: Cardiac functional imaging; Ejection fraction; Four-dimensional computed tomography; Heart failure; Radiation exposure; Systolic
• ISSN: 2352-0477; 2352-0477
• DOI: 10.1016/j.ejro.2024.100583

This prospective study tested the diagnostic accuracy, and absolute agreement with MRI of a low-dose CT protocol for left ventricular ejection fraction (LVEF) measurement. Furthermore we assessed its potential for combining it with Chest-Abdomen-Pelvis CT (CAP-CT) for a one-stop examination. Eighty-two patients underwent helical low-dose CT. Cardiac magnetic resonance imaging (MRI) was the reference standard. In fifty patients, CAP-CT was performed concurrently, using a modified injection protocol. In these, LVEF was measured with radioisotope cardiography (MUGA). Patients >18 years, without contrast media or MRI contraindications, were included. Bias was measured with Bland-Altman analysis, classification accuracy with Receiver Operating Characteristics, and inter-reader agreement with Intra-Class Correlation Coefficient (ICC). Correlation was examined using Pearson's correlation coefficients. CAP image quality was compared to previous scans with visual grading characteristics. The mean CT dose-length-product (DLP) was 51.8 mGycm, for an estimated effective dose of 1.4 mSv, compared to 5.7 mSv for MUGA. CT LVEF bias was between 2 % and 10 %, overestimating end-diastolic volume. When corrected for bias, sensitivity and specificity of 100 and 98.5 % for classifying reduced LVEF (50 % MRI value) was achieved. ICC for MUGA was significantly lower than MRI and CT. Distinction of renal medulla and cortex was reduced in the CAP scan, but proportion of diagnostic scans was not significantly different from standard protocol. When corrected for inter-modality bias, CT classifies patients with reduced LVEF with high accuracy at a quarter of MUGA dose and can be combined with CAP-CT without loss of diagnostic quality. •CT can measure ejection fraction (LVEF) at a quarter of MUGA dose.•Absolute LVEF bias to MRI was proven but classification accuracy was excellent.•LVEF can be measured as part of chest-abdomen-pelvis CT, at preserved image quality.•The combined protocol could be performed within in a normal CT timeslot.•A one-stop CT protocol for cancer- and carditoxicity monitoring is feasible.