title: The cardiothoracic ratio on post-mortem computer tomography.
abstract: In clinical practice, the cardiothoracic ratio (CTR) was first utilized on plain chest radiography, and subsequently with computed tomography (CT) to diagnose cardiomegaly with a threshold of 0.5. Using CTR in forensic practice could help to detect cardiomegaly on post-mortem CT (PMCT) prior to the autopsy. However, an adaption of the threshold could be necessary because of post-mortem changes. Our retrospective study aimed to measure the CTR on PMCT and test the possible influence of variables. We selected 109 autopsy cases in which the heart weight was within normal limits. A forensic pathologist and a radiologist measured separately the CTR on axial and scout views on PMCT. We tested the statistical concordance between the two readers and between the axial and scout view and identified factors that could be associated with a modification of the CTR. The CTR measurements revealed an overestimation of the measurements made on scout compared to axial view. The inter-reader correlation was very high for both views. Among the different variables statistically tested, heart dilatation and body mass index (BMI) were the only two factors statistically associated with an augmentation of the CTR. The CTR can be useful in the diagnosis of cardiomegaly on PMCT. However, dilatation of the cardiac chambers caused by acute heart failure may be misinterpreted radiographically as cardiomegaly. Inter-observer reliability in our study was very high. CTR may be overestimated when measured on the scout view. Further investigations with larger cohorts, including cases with cardiac hypertrophy, are necessary to better understand the relationship between radiological CTR and the morphology of the heart.
authors.affiliation: CURML, Chemin de la Vulliette 4, 1000, Lausanne, Switzerland. morgane.jotterand@chuv.ch.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-0040-1934
authors.initials: M
authors.lastname: Jotterand
authors.affiliation: Service de Radiologie, CHUV, rue du Bugnon 21, 1011, Lausanne, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Doenz
authors.affiliation: CURML, Chemin de la Vulliette 4, 1000, Lausanne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Grabherr
authors.affiliation: CEPIC, route de la Corniche 2, 1066, Epalinges, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Faouzi
authors.affiliation: CURML, Chemin de la Vulliette 4, 1000, Lausanne, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Boone
authors.affiliation: CURML, Chemin de la Vulliette 4, 1000, Lausanne, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Mangin
authors.affiliation: CURML, Chemin de la Vulliette 4, 1000, Lausanne, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Michaud
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D006332:Cardiomegaly / Q000175:diagnosis*; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D005260:Female; D049429:Forensic Pathology; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015588:Observer Variation; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D055815:Young Adult
keywords: Cardiomegaly; Cardiothoracic ratio; Heart dilatation; Post-mortem CT scanner PMCT