International Journal of Research in Medical Sciences | March 2020 | Vol 8 | Issue 3 Page 946 International Journal of Research in Medical Sciences Rana YR et al. Int J Res Med Sci. 2020 Mar;8(3):946-953 www.msjonline.org pISSN 2320-6071 | eISSN 2320-6012 Original Research Article Double outlet of right ventricle: imaging spectrum on multi-slice computed tomography Yashpal R. Rana 1 , Dinesh L. Patel 1 *, Megha M. Sheth 1 , Nitisha A Jain 2 , Samir G. Patel 1 , Milin N. Garachh 1 INTRODUCTION Conotruncal anomalies are congenital heart defects that result from abnormal formation and septation of the outflow tracts (conotruncus) of the heart and great vessels. DORV is a type of conotruncal anomaly which encompasses a wide spectrum of anatomic malformations that are characterized by origin of both the aorta and pulmonary arterial trunks entirely or predominately from the morphological right ventricle (RV). 1,2 When an arterial valve or valves override(s) the ventricular septum through a VSD, a ‘50% rule’ is applied. 3 By this rule, an overriding arterial trunk is considered as arising from the RV when more than half of the circumference of its valve belongs to the RV. As the term “DORV” describes a form of ventriculoarterial connection, it occurs with any 1 Department of Radiology, U.N. Mehta Institute of Cardiology and Research Centre, Ahmedabad, Gujarat, India 2 Department of Radiology, Civil Hospital, B.J. Medical College, Ahmedabad, Gujarat, India Received: 16 December 2019 Revised: 27 December 2019 Accepted: 24 January 2020 *Correspondence: Dr. Dinesh L. Patel, E-mail: drdineshpatel1965@gmail.com Copyright: © the author(s), publisher and licensee Medip Academy. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Background: Multi-slice computed tomography (MSCT) is the main stay of pre-operative assessment of many complex congenital heart diseases (CHD) in current clinical practice, one of them is double outlet of right ventricle (DORV). DORV is one of the conotruncal anomalies that encompasses a wide spectrum of anatomic malformations in which both the aorta and pulmonary arterial trunk arise entirely or predominantly from the morphologically right ventricle (RV). Purpose of this article is to understand spectrum of DORV and associated types of ventricular septal defect (VSD) on MSCT imaging with special emphasis of usefulness of 3-D volume rendered (VR) images in pre surgical evaluation. Methods: A total of 500 paediatric patients (<18 years old), who had undergone MSCT were studied during the period 2014 to 2019 at the tertiary cardiac care centre. Results: 500 patients having primary/suspicious diagnosis of DORV on echocardiography during the said period were enrolled in the study. All the patients who underwent MSCT scan, were studied in detail for: DORV spectrum, associated types of VSD and its relationship to the semilunar valves. Out of 500 total subjects, subaortic VSD was the most common type of VSD observed (53%), followed by subpulmonic VSD (22%), non-committed VSD (18%) and doubly committed VSD (7%). Associations of pulmonary stenosis, subaortic stenosis and aortic co-arctation with various types of VSDs were addressed. Associated other anomalies were also analysed. Conclusions: Advances in MSCT technology has revolutionized pre-surgical diagnosis, management approach and post-operative follow-up of DORV patients. Excellent image qualities along with 3D volume rendered images help surgeon understand complex morphology of DORV variants and associated types of VSD. Significant reduction in intra and post-operative mortality in DORV patients in current era is result of MSCT technology. Keywords: Double outlet of right ventricle, Multislice computed tomography, Ventricular septal defect, 3- Dimensional volume rendered technique DOI: http://dx.doi.org/10.18203/2320-6012.ijrms20200761