ARVD criteria

Importance of CMR within the task force criteria for the diagnosis of ARVC in children and adolescents.
Etoom Y, et al. JACC 2015;65:987-995.

MRI - Delayed enhancement (Congenital Aortic Stenosis)

Myocardial extracellular remodeling is associated with ventricular diastolic dysfunction in children and young adults with congenital aortic stenosis.

Dusenbery, SM, et al. JACC 2014;63(17):1778-85.

Objectives

This study sought to analyze cardiac magnetic resonance (CMR) measurements of myocardial extracellular volume fraction (ECV) and late gadolinium enhancement (LGE) in children and young adults with congenital aortic stenosis (AS) to determine the extent of fibrosis and examine their association with aortic valve and ventricular function.

Background

Patients with congenital AS frequently have impaired diastolic ventricular function and exercise capacity that may be related to myocardial fibrosis.

Methods

A total of 35 patients with congenital AS (median age 16 years) and 27 normal control subjects (median age 16 years) were evaluated by CMR. ECV was calculated from pre- and post-gadolinium contrast T1 measurements of blood and myocardium, and the hematocrit.

Results

ECV was significantly higher in AS patients than in normal subjects (median 0.27 [range 0.22 to 0.42] vs. 0.25 [range 0.18 to 0.27], p = 0.001). LGE was present in 8 (24%) of the AS patients. A higher ECV was correlated with echocardiographic indexes of diastolic dysfunction including a higher mitral E-wave z-score (r = 0.58, p = 0.002), E/septal E′ z-score (r = 0.56, p = 0.003), E/mean E′ z-score (r = 0.55, p = 0.003), and indexed left atrial volume (r = 0.56, p = 0.001). Other factors associated with an elevated ECV (>0.28) included a greater number of aortic valve interventions (p = 0.004) and a greater number of aortic valve balloon valvuloplasties (p = 0.003). ECV was not significantly associated with AS gradient, left ventricular mass, mass/volume ratio, or ejection fraction.

Conclusions

In young patients with AS, myocardial ECV is significantly elevated compared with control subjects and is associated with echocardiographic indexes of diastolic dysfunction. ECV measured by CMR may be a useful method for risk stratification and monitoring therapies targeting fibrosis.

MRI: Delayed enhancement in LVNC

Figure 1 Comparison of In Vivo CE-MRI and Histological Sections in LVNC
(A) Contrast-enhanced magnetic resonance imaging (CE-MRI) in short-axis view demonstrated that diffuse delayed enhancement occurred in the interventricular septum, left ventricular free wall, and the trabecular meshwork region of the left ventricle. (B) The histological section in isolated left ventricular noncompaction (LVNC) from the apical segment of the left ventricle demonstrated that fibrosis presented within trabeculations (arrow) as well as in compacted myocardium (arrowhead). In addition, mucoid degeneration (asterisk) was identified in endocardium. (Masson's Trichrome stain, original magnification x1).

J Am Coll Cardiol, 2011; 58:311-312,
© 2011 by the American College of Cardiology Foundation

RESEARCH CORRESPONDENCE

Histopathological Features of Delayed Enhancement Cardiovascular Magnetic Resonance in Isolated Left Ventricular Noncompaction

Yan Chaowu, PhD, MD*, Li Li, PhD and Zhao Shihua, PhD, MD

Contrast-enhanced magnetic resonance imaging (CE-MRI) is an important imaging modality for the evaluation of isolated left ventricular noncompaction (LVNC). The delayed gadolinium enhancement has been identified in both compacted and noncompacted myocardium, and it may correlate with the clinical severity of LVNC (1–3). However, little is known about the histological basis of myocardial delayed enhancement in LVNC patients, especially in the noncompacted myocardium. In this study, we made a comparison between the myocardial delayed enhancement and histological findings in a patient with LVNC who underwent heart transplantation.

A 27-year-old man was admitted with exertional dyspnea. Chest roentgenogram showed cardiomegaly with pulmonary venous congestion, and the cardiothoracic ratio was 72%. The LVNC was diagnosed by echocardiography, and the ratio of the noncompacted to compacted myocardium was 3.2. The left ventricular end-diastolic dimension was 63 mm, and left ventricular ejection fraction was 18%. Contrast-enhanced MRI was performed, and deep intertrabecular recesses presented in the apical and lateral wall of the left ventricle. The near-transmural delayed enhancement occurred in the interventricular septum, and diffuse enhancement presented in the free wall and the trabecular meshwork region of the left ventricle. In addition, CE-MRI detected the left ventricular thrombus and pericardial and pleural effusions. One week later, informed consent was obtained, and heart transplantation was carried out. The pathological findings of the explanted heart were compared with the previous in vivo CE-MRI (Fig. 1 ). In the compacted myocardium with delayed enhancement, extensive fibrosis was identified and predominantly localized in the mid-myocardial wall. The collagen volume fraction was 27.9% in the histological section, which came from the region of near-transmural delayed enhancement in the interventricular septum. In the noncompacted myocardium with delayed enhancement (the trabecular meshwork region of left ventricle), however, 2 types of pathological findings presented: mucoid degeneration in the endocardium and fibrosis within the trabeculations. The collagen volume fraction of trabeculations was 37.4% in the left ventricular apex and 32.8% in the lateral wall of the left ventricle. In the myocardial regions without delayed enhancement, there was no significant increase in the amount of fibrosis. The epicardial coronary arteries were normal in the patient.

The results of this study demonstrated that fibrosis was identified histologically in both compacted and noncompacted myocardium. In the compacted myocardium, the regions of delayed enhancement corresponded well with the focally increased fibrosis. Furthermore, CE-MRI may overestimate the degree of fibrosis replacement, as we found in the interventricular septum. In the noncompacted myocardium, delayed enhancement was associated with fibrosis within the trabeculations as well as mucoid degeneration in the endocardium.
Previous studies have showed that myocardial delayed enhancement presented in patients with LVNC, and it has been proposed that the regions of delayed enhancement probably reflected the regions of increased myocardial fibrosis (1,2). Pathological analysis also demonstrated that fibrosis occurred in the left ventricular myocardium of LVNC patients (4,5). However, further research was lacking to assess the histopathological correlation of myocardial delayed enhancement in LVNC. In the present study, our findings show that the fibrosis is the histological basis in the delayed enhancement of compacted myocardium; however, it is still unknown which mechanism plays the leading role in the delayed enhancement of noncompacted myocardium.

Cath: Novelties. Fusing MRI with X-ray

Published ahead of print. Accessed on 5/2/2011
Circulation: Cardiovascular Imaging

X-ray Magnetic Resonance Fusion to Internal Markers and Utility in Congenital Heart Disease Catheterization

Yoav Dori1*, et al.
The Children's Hospital of Philadelphia, Philadelphia, PA & Siemens Healthcare, Malvern, PA
Corresponding author; email: doriy@email.chop.edu

Abstract
Background—X-ray magnetic resonance fusion (XMRF) allows for utilization of 3D data during cardiac catheterization. However, to date, technical requirements have limited the use of this modality in clinical practice. Here we report on a new internal marker XMRF method that we have developed and describe how we used XMRF during cardiac catheterization in congenital heart disease.

Methods and Results—XMRF was performed in a phantom and in 23 patients presenting for cardiac catheterization who also needed cardiac MRI for clinical reasons. The registration process was performed in less than 5 minutes per patient with minimal radiation (0.004 - 0.024 mSv) and without contrast. Registration error was calculated in a phantom and in 8 patients using the maximum distance between angiographic and 3D model boundaries. In the phantom the measured error in the AP projection had a mean of 1.15 mm (standard deviation 0.73). The measured error in patients had a median of 2.15 mm (IQR 1.65 - 2.56 mm). Internal markers included bones, airway, image artifact, calcifications, and the heart and vessel borders. The MRI data was used for road mapping in 17/23 (74%) cases and camera angle selection in 11/23 (48%) cases.

Conclusions—Internal markers based registration can be performed quickly, with minimal radiation, without the need for contrast, and with clinically acceptable accuracy using commercially available software. We have also demonstrated several potential uses for XMRF in routine clinical practice. This modality has the potential to reduce radiation exposure and improve catheterization outcomes.

Two video links:
http://circimaging.ahajournals.org/content/suppl/2011/04/29/CIRCIMAGING.111.963868.DC1/Video1.mov

Video showing MRI fusion with fluoro guiding cath procedure:
http://circimaging.ahajournals.org/content/suppl/2011/04/29/CIRCIMAGING.111.963868.DC1/Video2.mov

Images: Raghib complex

Raghib complex:
Persistent LSVC to LA
Absent Coronary sinus (considered unroofed)
ASD at the inferior part of atrial septum
JACC 2022;57:e15 (Images in Cardiology)

MRI: Early detection of Doxorubincin-induced cardiomyopathy

Early Detection of Doxorubicin Cardiotoxicity Using Gadolinium EnhancedCardiovascular Magnetic Resonance ImagingJames C. Lightfoot, Ralph B. D'Agostino, Jr, Craig A. Hamilton, JenniferJordan, Frank M. Torti, Nancy D. Kock, James Jordan, Susan Workman, and W.Gregory HundleyCirc Cardiovasc Imaging published 9 July 2010,10.1161/CIRCIMAGING.109.918540
http://circimaging.ahajournals.org/cgi/content/abstract/CIRCIMAGING.109.918540v1?papetoc