Usefulness of 3D reconstructed computed tomography imaging for double outlet right ventricle

Double Outlet Right Ventricle: In-Depth Anatomic Review Using Three-Dimensional Cardiac CT Data

Double outlet right ventricle (DORV) is a relatively common congenital heart disease in which both great arteries are connected completely or predominantly to the morphologic RV. Unlike other congenital heart diseases, DORV demonstrates various anatomic and hemodynamic subtypes, mimicking ventricular septal defect, tetralogy of Fallot, transposition of the great arteries, and functional single ventricle. Because different surgical strategies are applied to different subtypes of DORV with ventricular septal defects, a detailed assessment of intracardiac anatomy should be performed preoperatively. Due to high spatial and contrast resolutions, cardiac CT can provide an accurate characterization of various intracardiac morphologic features of DORV. In this pictorial essay, major anatomic factors affecting surgical decision-making in DORV with ventricular septal defects were comprehensively reviewed using three-dimensional cardiac CT data. In addition, the surgical procedures available for these patients and major postoperative complications are described.

Cross-sectional imaging of congenital pulmonary artery anomalies

Congenital pulmonary artery (PA) anomalies comprise a rare and heterogeneous spectrum of disease, ranging from abnormal origins to complete atresia. They may present in early infancy or more insidiously in adulthood, often in association with congenital heart disease such as tetralogy of Fallot or other syndromes. In recent years, cross-sectional imaging, including computed tomography (CT) and magnetic resonance imaging (MRI), has become widely utilized for the noninvasive assessment of congenital PA diseases, supplementing echocardiography and at times supplanting invasive angiography. In this article, modern CT and MRI techniques for imaging congenital PA disorders are summarized. The key clinical features, cross-sectional imaging findings, and treatment options for the most commonly encountered entities are then reviewed. Emphasis is placed on the ever-growing role of cross-sectional imaging options in facilitating early and accurate diagnosis and tailored treatment.

Fetal Cardiac Impairment in Nitrofen-Induced Congenital Diaphragmatic Hernia: Postmortem Microcomputed Tomography Imaging Study

INTRODUCTION

We assessed the post-mortem micro-CT utility to evaluate fetal cardiac impairment in nitrofen-induced congenital diaphragmatic hernia (CDH).

METHODS

At 9.5d postconception (dpc), pregnant rats were exposed to nitrofen. At +18 and +21dpc, fetuses were harvested by cesarean section. Postmortem micro-CT and autopsy were performed. Fetuses were assigned to three experimental groups: Control group (C), Nitrofen group (N, exposition to nitrofen without CDH), CDH group. Cardio-pulmonary indices were evaluated.

RESULTS

An accurate morphological evaluation of the lung and heart was obtained. Early cardiac impairment was present in the N and CDH groups. At term pregnancy, an increased maximum diameter and decreased minimum diameter of the ventricles and increased interventricular septal thickness were noted in CDH. Histology showed a myocardial "disarray" and an high density of mitotic myocytes in CDH at midgestation.

CONCLUSIONS

The potential utility of post-mortem fetal micro-CT examination in CDH was introduced. The results highlighted the presence of cardiac adaptation in affected fetuses.

Three-Dimensional Reconstruction of Intracardiac Anatomy Using CTA and Surgical Planning for Double Outlet Right Ventricle: Early Experience at a Tertiary Care Congenital Heart Center

BACKGROUND

Although transthoracic echocardiography (TTE) routinely establishes the diagnosis of double outlet right ventricle (DORV), it can be suboptimal for depicting exact ventricular septal defect (VSD) position, especially with respect to the outflow tracts. Advanced imaging with computed tomography angiography (CTA) can help visualize structures and relationships not easily seen by echo. Using computer-aided design, we have the ability to create three-dimensional (3D) models of the intracardiac anatomy, which can be helpful for better depicting the overall anatomy to assist surgical planning.

METHODS

Patients with a diagnosis of DORV were retrospectively reviewed at our institution from October 2013 to April 2015. Patients who preoperatively underwent both TTE and CTA with 3D reconstruction of the intracardiac anatomy were included. Computed tomography angiography findings with 3D intracardiac model creation were compared to the surgical findings.

RESULTS

Twenty-five patients underwent surgical repair of DORV during the study period. Five patients had CTA with 3D reconstruction, in addition to the standard TTE images, and were included in the study. In all five cases, CTA with 3D reconstruction of the intracardiac anatomy accurately depicted the VSD position relative to important adjacent structures, including the outflow tracts.

CONCLUSION

Three-dimensional reconstruction of the intracardiac anatomy using CTA data can provide accurate data for presurgical planning of DORV repair and has the potential for being especially useful in patients for whom intracardiac anatomy and VSD position cannot be well seen by TTE. A larger prospective analysis is warranted to help validate this approach.

Illustrated Imaging Essay on Congenital Heart Diseases: Multimodality Approach Part III: Cyanotic Heart Diseases and Complex Congenital Anomalies

From the stand point of radiographic analysis most of the complex cyanotic congenital heart diseases (CHD), can be divided into those associated with decreased or increased pulmonary vascularity. Combination of a specific cardiac configuration and status of lung vasculature in a clinical context allows plain film diagnosis to be predicted in some CHD. Correlation of the position of the cardiac apex in relation to the visceral situs is an important information that can be obtained from the plain film. This information helps in gathering information about the atrio-ventricular, ventricular arterial concordance or discordance. Categorization of the cyanotic heart disease based on vascularity is presented below. Thorough understanding of cardiac anatomy by different imaging methods is essential in understanding and interpreting complex cardiac disease. Basic anatomical details and background for interpretation are provided in the previous parts of this presentation.

In Vivo CT Direct Volume Rendering: A Three-Dimensional Anatomical Description of the Heart

BACKGROUND

Since cardiac anatomy continues to play an important role in the practice of medicine and in the development of medical devices, the study of the heart in three dimensions is particularly useful to understand its real structure, function and proper location in the body.

MATERIAL/METHODS

This study demonstrates a fine use of direct volume rendering, processing the data set images obtained by Computed Tomography (CT) of the heart of 5 subjects with age range between 18 and 42 years (2 male, 3 female), with no history of any overt cardiac disease. The cardiac structure in CT images was first extracted from the thorax by marking manually the regions of interest on the computer, and then it was stacked to create new volumetric data.

RESULTS

The use of a specific algorithm allowed us to observe with a good perception of depth the heart and the skeleton of the thorax at the same time. Besides, in all examined subjects, it was possible to depict its structure and its position within the body and to study the integrity of papillary muscles, the fibrous tissue of cardiac valve and chordae tendineae and the course of coronary arteries.

CONCLUSIONS

Our results demonstrated that one of the greatest advantages of algorithmic modifications of direct volume rendering parameters is that this method provides much necessary information in a single radiologic study. It implies a better accuracy in the study of the heart, being complementary to other diagnostic methods and facilitating the therapeutic plans.

Assessment of Double Outlet Right Ventricle Associated with Multiple Malformations in Pediatric Patients Using Retrospective ECG-Gated Dual-Source Computed Tomography

Purpose

To evaluate the feasibility and diagnostic accuracy of retrospective electrocardiographically (ECG)-gated dual-source computed tomography (DSCT) for the assessment of double outlet right ventricle (DORV) and associated multiple malformations in pediatric patients.

Materials and Methods

Forty-seven patients <10 years of age with DORV underwent retrospective ECG-gated DSCT. The location of the ventricular septal defect (VSD), alignment of the two great arteries, and associated malformations were assessed. The feasibility of retrospective ECG-gated DSCT in pediatric patients was assessed, the image quality of DSCT and the agreement of the diagnosis of associated malformations between DSCT and transthoracic echocardiography (TTE) were evaluated, the diagnostic accuracies of DSCT and TTE were referred to surgical results, and the effective doses were calculated.

Results

Apart from DORV, 109 associated malformations were confirmed postoperatively. There was excellent agreement (κ = 0.90) for the diagnosis of associated malformations between DSCT and TTE. However, DSCT was superior to TTE in demonstrating paracardiac anomalies (sensitivity, coronary artery anomalies: 100% vs. 80.00%, anomalies of great vessels: 100% vs. 88.57%, separate thoracic and abdominal anomalies: 100% vs. 76.92%, respectively). Combined with TTE, DSCT can achieve excellent diagnostic performance in intracardiac anomalies (sensitivity, 91.30% vs. 100%). The mean image quality score was 3.70 ± 0.46 (κ = 0.76). The estimated mean effective dose was < 1 mSv (0.88 ± 0.34 mSv).

Conclusions

Retrospective ECG-gated DSCT is a better diagnostic tool than TTE for pediatric patients with complex congenital heart disease such as DORV. Combined with TTE, it may reduce or even obviate the use of invasive cardiac catheterization, and thus expose the patients to a much lower radiation dose.

Imaging of temporomandibular joint: approach by direct volume rendering

BACKGROUND

The purpose of this study was to conduct a morphological analysis of the temporomandibular joint, a highly specialized synovial joint that permits movement and function of the mandible.

MATERIALS AND METHODS

We have studied the temporom-andibular joint anatomy, directly on the living, from 3D images obtained by medical imaging Computed Tomography and Nuclear Magnetic Resonance acquisition, and subsequent re-engineering techniques 3D Surface Rendering and Volume Rendering. Data were analysed with the goal of being able to isolate, identify and distinguish the anatomical structures of the joint, and get the largest possible number of information utilizing software for post-processing work.

RESULTS

It was possible to reproduce anatomy of the skeletal structures, as well as through acquisitions of Magnetic Resonance Imaging; it was also possible to visualize the vascular, muscular, ligamentous and tendinous components of the articular complex, and also the capsule and the fibrous cartilaginous disc. We managed the Surface Rendering and Volume Rendering, not only to obtain three-dimensional images for colour and for resolution comparable to the usual anatomical preparations, but also a considerable number of anatomical, minuter details, zooming, rotating and cutting the same images with linking, graduating the colour, transparency and opacity from time to time.

CONCLUSION

These results are encouraging to stimulate further studies in other anatomical districts.

Right ventricular outflow tract imaging with CT and MRI: Part 1, Morphology

OBJECTIVE

MRI and CT have become the ideal methods for assessing the complex morphology of the conotruncal region, including the right ventricular outflow tract (RVOT). Detailed information about the embryology and anatomy of the RVOT provides a better understanding of the spectrum of diseases of this region and helps to narrow the differential diagnoses of abnormalities involving this important structure. In this review, we focus on the role of CT and MRI to evaluate morphology in relation to developmental malformation of the RVOT.

CONCLUSION

A spectrum of conotruncal anomalies with abnormally positioned great arteries may arise from a perturbation of RVOT formation. Complications after surgery are common, and many patients need follow-up imaging for diagnosis and surgical planning. In this regard, the spectrum of diseases, differential diagnoses, and postoperative findings are briefly described. With CT and MRI, the relationship of the RVOT to critical structures, such as the coronary arteries, can be revealed.