Tissue-Velocity Magnetic Resonance Imaging and Tissue Doppler Imaging to Assess Regional Myocardial Diastolic Velocities at the Right Ventricle in Corrected Pediatric Tetralogy of Fallot Patients:

Three-Dimensional Tricuspid Annular Motion Analysis from Cardiac Magnetic Resonance Feature-Tracking

Right ventricular (RV) dysfunction is known to be highly correlated with mortality and morbidity; nevertheless, imaging-based assessment of RV anatomy and physiology lags far behind that of the left ventricle. In this study, we advance RV imaging using cardiac magnetic resonance (CMR) to accomplish the following aims: (i) track the motion of six tricuspid annular (TA) sites using a semi-automatic tracking system; (ii) extract clinically important TA measurements-systolic velocity (Sm), early diastolic velocity (Em), late diastolic velocity (Am), and TA plane systolic excursion (TAPSE)-for each TA site and compare these CMR-derived measurements in healthy subjects vs. patients with heart failure, repaired tetralogy of Fallot, pulmonary hypertension, and hypertrophic cardiomyopathy; (iii) investigate how the TA motion related measurements compare with information provided by invasive right heart catheterization (RHC); (iv) evaluate the rate of change in surface area swept out by the reconstructed tricuspid annulus over time and (v) assess the reproducibility of this CMR-based technique. Results indicate that TA motion parameter data obtained in three dimensions using the proposed CMR-based systematic methodology achieve superior diagnostic performance (Sm: AUC = 0.957; TAPSE: AUC = 0.981) compared to two-dimensional CMR imaging. Both Sm and TAPSE from CMR correlated positively with dP/dt _max/IP from RHC (Sm: r = 0.621, p < 0.01; TAPSE: r = 0.648, p < 0.01). Our highly reproducible and robust methodology holds potential for extending CMR imaging to characterization of TA morphology and dynamic behaviour, eventually leading to deeper understanding of RV function and improved diagnostic capability.

Preliminary Assessment of Tricuspid Valve Annular Velocity Parameters by Cardiac Magnetic Resonance Imaging in Adults with a Volume-Overloaded Right Ventricle: Comparison of Unrepaired Atrial Septal Defect and Repaired Tetralogy of Fallot

The aim is to compare tricuspid valve (TV) atrioventricular junction (AVJ) annular motion parameters in unrepaired atrial septal defect (ASD) and repaired Tetralogy of Fallot (TOF) by cardiac magnetic resonance (CMR) imaging. We retrospectively reviewed CMR studies performed between November 2007 and November 2013 in patients 16-45 years of age with unrepaired ASD (with or without partial anomalous pulmonary venous return) and with repaired TOF, who had previous infundibulotomy, but have not undergone pulmonary valve replacement. Longitudinal motion of lateral TV in four-chamber view cine image was tracked through the cardiac cycle with custom software. Twenty TOF patients and 12 ASD patients were included, and values were compared with 80 controls. Right ventricular end-diastolic volume index and right ventricular end-systolic volume index were similar in the ASD and TOF groups and were significantly higher in both groups than in controls. Maximum displacement of the TV in systole, velocity at half-maximal displacement during systole, and velocity at half-maximal displacement during early diastole were all significantly lower in the TOF group than the ASD group [1.39 ± 0.47 vs. 2.21 ± 0.46 (cm, p < 0.01), 5.9 ± 2.1 vs. 10.1 ± 2.3 (cm/s, p < 0.01), and 7.7 ± 2.6 vs. 10.9 ± 3.1 (cm/s, p < 0.05)]. TOF patients have diminished early diastolic TV AVJ velocity compared to patients with an unrepaired ASD, despite similar RV volumes. This observation could suggest diastolic dysfunction or cardiac mechanics unique to the postoperative, volume-overloaded right ventricle in patients with repaired TOF.

Ventricular performance after surgery for a congenital heart defect as assessed using advanced echocardiography: from doppler flow to 3D echocardiography and speckle-tracking strain imaging

A varying degree of impairment of ventricular performance is observed over the long-term after surgery for a congenital heart defect (CHD). Impaired ventricular performance has been shown to be of prognostic value for increased risk of cardiovascular events in adult CHD patients. This emphasizes the importance of delineating the timing and cause of this postoperative impairment. Impairment of ventricular performance could develop over time as a consequence of residua, sequelae and complications of the CHD or surgical procedure. Yet, impaired ventricular performance has also been observed immediately after surgery and can persist and/or worsen over time. This postoperative impairment of ventricular performance is the focus of this review. This article provides an overview of echocardiographic techniques currently used to assess ventricular performance. Furthermore, we review current literature describing ventricular performance, as assessed using echocardiography, after correction of a CHD. In general, a decrease in ventricular performance is observed directly after surgery for CHD’s. Subsequent follow-up of ventricular performance is characterized by a varying degree of postoperative recovery. A consistent observation is the persistent impairment of right-ventricular performance after repair in several different subgroups of CHD patients ranging from ventricular septal defect repair to surgery for Tetralogy of Fallot.

A historical overview of magnetic resonance imaging, focusing on technological innovations

Magnetic resonance imaging (MRI) has now been used clinically for more than 30 years. Today, MRI serves as the primary diagnostic modality for many clinical problems. In this article, historical developments in the field of MRI will be discussed with a focus on technological innovations. Topics include the initial discoveries in nuclear magnetic resonance that allowed for the advent of MRI as well as the development of whole-body, high field strength, and open MRI systems. Dedicated imaging coils, basic pulse sequences, contrast-enhanced, and functional imaging techniques will also be discussed in a historical context. This article describes important technological innovations in the field of MRI, together with their clinical applicability today, providing critical insights into future developments.