Limitations of cardiothoracic ratio derived from chest radiographs to predict real heart size: comparison with magnetic resonance imaging

Insights into Imaging

Manuel Gutierrez Gimeno¹  Diana Penha¹  David McCreavy¹  Jurate Noreikaite¹  Paulius Simkus¹  Monika Arzanauskaite²  Audra Banisauskaite³ 

[1]Radiology Department, Liverpool Heart and Chest Hospital, Thomas Drive, L14 3PE, Liverpool, UK

[2]Radiology Department, Liverpool Heart and Chest Hospital, Thomas Drive, L14 3PE, Liverpool, UK

[3]Cardiovascular Research Center-ICCC, Hospital de La Santa Creu I Sant Pau, IIB-Sant Pau, Barcelona, Spain

[4]Radiology Department, Liverpool Heart and Chest Hospital, Thomas Drive, L14 3PE, Liverpool, UK

[5]Department of Radiology, Lithuanian University of Health Sciences, Eiveniu 2, 50161, Kaunas, Lithuania

关键词: Cardiothoracic ratio;    Cardiac magnetic resonance imaging;    Chest radiograph;    Cardiac imaging;   

DOI  :  10.1186/s13244-021-01097-0

来源: Springer

【 摘 要 】

BackgroundCardiothoracic ratio (CTR) in chest radiographs is still widely used to estimate cardiac size despite the advent of newer imaging techniques. We hypothesise that a universal CTR cut-off value of 50% is a poor indicator of cardiac enlargement. Our aim was to compare CTR with volumetric and functional parameters derived from cardiac magnetic resonance imaging (MRI).Methods309 patients with a chest radiograph and cardiac MRI acquired within a month were reviewed to assess how CTR correlates with multiple cardiac MRI variables: bi-ventricular EDV (absolute and indexed to body surface area), EF, indexed total heart volume and bi-atrial areas. In addition, we have also determined CTR accuracy by creating multiple ROC curves with the described variables.ResultsAll cardiac MRI variables correlate weakly but statistically significantly with CTR. This weak correlation is explained by a substantial overlap of cardiac MRI parameters in patients with normal and increased CTR. For all variables, CTR was only mildly to moderately better than a chance to discriminate cardiac enlargement (AUC 0.6–0.7). Large CTR values (> 55%) are specific but not sensitive, while low CTR values (< 45%) are sensitive but not specific. Values in between are not sensitive nor specific.ConclusionsCTR correlates weakly with true chamber size assessed by gold standard cardiac MRI and has a weak discriminatory power. Thus, clinical decisions based on intermediate CTRs (45–55%) should be avoided. Large CTRs (> 55%) are likely indicative of true heart chamber enlargement. Low CTRs (< 45%) are likely indicative of normal heart size.

【 授权许可】

CC BY