Validation of left ventricular circumferential area as a surrogate for heart weight on postmortem computed tomography G.M. Hatch a,b , G. Ampanozi a,c , M.J. Thali c , T.D. Ruder a,c,d,n a Center of Forensic Imaging and Virtopsy, Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH-3012, Bern, Switzerland b Radiology-Pathology Center for Forensic Imaging, Departments of Radiology and Pathology, University of New Mexico School of Medicine, MSC07 4040, 1101 Camino de Salud NE, University of New Mexico, Albuquerque, NM 87102, USA c Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, University of Zürich, Winterthurerstrasse 190/52, CH-8057, Zürich, Switzerland d Institute of Diagnostic, Interventional and Pediatric Radiology, University Hospital, CH-3010 Bern, Switzerland article info Article history: Received 7 May 2013 Received in revised form 19 May 2013 Accepted 20 May 2013 Available online 12 June 2013 Keywords:: Computed tomography Cardiomegaly Left ventricular size Cardio-thoracic ratio Postmortem imaging abstract Objectives: Cardiomegaly has important medical and forensic implications. Left ventricular circumfer- ential area (LVCA) has been proposed as a simple and effective measure of heart weight. We determined if LVCA reflects actual heart weight, as measured at autopsy. Methods: Two blinded radiologist independently and retrospectively measured the LVCA, in postmortem computed tomography scans of 50 decedents (34 male, 16 female, mean age 53 years). Actual heart weight was obtained from the written autopsy record. Calculated heart weight was derived using a linear regression equation describing the relationship between mean measured heart weight and actual heart weight. Results: The mean actual heart weight was 416.6 g (median 395.0 g, range 250.0–770.0 g, SD 97.9). The mean measured LVCA was 3756.3 mm 2 (range 2133.5–7083.0 mm 2 , SD 794.2). There was a significant and strong positive correlation between the mean measured LVCA and actual heart weight (p o0.0001, correlation coefficient 0.707). There was no significant inter-observer variability. There was no significant difference between calculated heart weight and autopsy heart weight. Conclusions: LVCA and calculated heart weight reflect actual heart weight, as measured at autopsy. These results suggest that heart weight estimation can be performed on non-contrast postmortem CT, using a linear regression equation based on the LVCA. & 2013 Elsevier Ltd. All rights reserved. 1. Introduction The evaluation of cardiomegaly is a critical factor in early disease detection, pre-surgical screening, disease therapy, and post-mortem medico-legal investigation. Cardiomegaly may reflect increased heart size and/or mass; frequently, both occur in concert [1]. From the radiologist's standpoint, heart size (and implicitly the heart weight) has been traditionally and perhaps most frequently estimated using the cardiothoracic ration (CTR) on chest radiographs. However, the sensitivity of the CTR is poor [2]. Recent work proposed a simple measurement of two dimensional left ventricular area (2D LV area), as measured on antemortem, non-contrast computed tomography (CT), as an accurate approx- imation of left ventricular (LV) muscle mass, volume and size, using three-dimensional (3D) volume data from contrast enhanced CT images as a gold standard [3]. An accurate and simple estimation of heart weight on non-contrast CT is useful for both clinical and forensic evaluation, particularly if the estimation is derived from actual heart weight, rather than approximations calculated from imaged volume and average density. The present study evaluated the 2D LV area—referred to as the left ventricular circumferential area (LVCA) in the remainder of this text—as a surrogate for heart weight, with autopsy heart weight correlation. 2. Materials and methods 2.1. Subjects The study was approved by both our institutional review board and the public prosecution department. We retrospectively eval- uated 70 consecutive cases of adult decedents who underwent both routine postmortem CT (PMCT) and autopsy for medico-legal death investigation at our institute. Out of these 70 subjects, Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/jofri Journal of Forensic Radiology and Imaging 2212-4780/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jofri.2013.05.002 n Corresponding author at: Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, University of Zürich, Winterthurerstrasse 190/52, CH-8057, Zürich, Switzerland. Tel.: +41 44 635 5611; fax: +41 44 635 6851. E-mail address: thomas_ruder@hotmail.com (T.D. Ruder). Journal of Forensic Radiology and Imaging 1 (2013) 98–101