Free-breathing high resolution modified Dixon steady-state angiography with compressed sensing for the assessment of the thoracic vasculature in pediatric patients with congenital heart disease

Abstract

Background Cardiovascular magnetic resonance angiography (CMRA) is a non-invasive imaging modality of choice in pediatric patients with congenital heart disease (CHD). This study was aimed to evaluate the diagnostic utility of a respiratory- and electrocardiogram-gated steady-state CMRA with modified Dixon (mDixon) fat suppression technique and compressed sensing in comparison to standard first-pass CMRA in pediatric patients with CHD at 3 T. Methods In this retrospective single center study, pediatric CHD patients who underwent CMR with first-pass CMRA followed by mDixon steady-state CMRA at 3 T were analyzed. Image quality using a Likert scale from 5 (excellent) to 1 (non-diagnostic) and quality of fat suppression were assessed in consensus by two readers. Blood-to-tissue contrast and quantitative measurements of the thoracic vasculature were assessed separately by two readers. CMRA images were reevaluated by two readers for additional findings, which could be identified only on either one of the CMRA types. Paired Student t test, Wilcoxon test, and intraclass correlation coefficients (ICCs) were used for statistical analysis. Results 32 patients with CHD (3.3 ± 1.7 years, 13 female) were included. Overall image quality of steady-state mDixon CMRA was higher compared to first-pass CMRA (4.5 ± 0.5 vs. 3.3 ± 0.5; P < 0.001). Blood-to-tissue contrast ratio of steady-state mDixon CMRA was comparable to first-pass CMRA (7.85 ± 4.75 vs. 6.35 ± 2.23; P = 0.133). Fat suppression of steady-state mDixon CMRA was perfect in 30/32 (94%) cases. Vessel diameters were greater in first-pass CMRA compared to steady-state mDixon CMRA with the greatest differences at the level of pulmonary arteries and veins (e.g., right pulmonary artery for reader 1: 10.4 ± 2.4 vs. 9.9 ± 2.3 mm, P < 0.001). Interobserver agreement was higher for steady-state mDixon CMRA for all measurements compared to first-pass CMRA (ICCs > 0.92). In 9/32 (28%) patients, 10 additional findings were identified on mDixon steady-state CMRA (e.g., partial anomalous venous return, abnormalities of coronary arteries, subclavian artery stenosis), which were not depicted using first-pass CMRA. Conclusions Steady-state mDixon CMRA offers a robust fat suppression, a high image quality, and diagnostic utility for the assessment of the thoracic vasculature in pediatric CHD patients.

Non-contrast free-breathing 2D CINE compressed SENSE T1-TFE cardiovascular MRI at 3T in sedated young children for assessment of congenital heart disease

“…These are also demonstrated in the present study, e.g., in the right atrium ( Fig 2C ), the aortic arch ( Fig 3C ), and the pulmonary veins ( Fig 4A ). In fact, similar techniques have been reported with contrast administration for improved tissue contrast [ 44 , 45 ]. In addition, Dixon-based techniques only provide static images at typically end-diastolic phase.…”

“…These techniques have shown promise for the depiction of intra- and extracardiac structures. However, their drawbacks typically include limited blood-to-tissue contrast for certain anatomical structures and possible water-fat-swap artifacts [ 43 , 44 ]. These are also demonstrated in the present study, e.g., in the right atrium ( Fig 2C ), the aortic arch ( Fig 3C ), and the pulmonary veins ( Fig 4A ).…”

Non-contrast free-breathing 3D cardiovascular magnetic resonance angiography using REACT (relaxation-enhanced angiography without contrast) compared to contrast-enhanced steady-state magnetic resonance angiography in complex pediatric congenital heart disease at 3T

“…So far there is no standard approach for gadolinium-free CMRA in children with complex CHD. To accurately assess vessel diameter and clearly visualize even small vessels and vascular connections in CHD, high spatial resolution cardiac and respiratory gated CMRA is often complementary performed to time resolved multiphase CMRA [ 23 ]. However, its acquisition requires additional contrast agent administration.…”

“…The high-resolution single-phase steady-state CMRA was acquired during a slow infusion (flow rate: 0.1–0.3 ml/s) of a gadolinium-based contrast agent at a dose of 0.1 mmol per kg of body weight (Gadobutrol, Gadovist, Bayer Healthcare, Berlin, Germany). Dual-echo Dixon readout was used to achieve fat removal in water images [ 20 , 23 ]. Respiratory navigator gating for end-expiration and ECG triggering for end-diastole was applied for data acquisition.…”

Cardiac cine with compressed sensing real-time imaging and retrospective motion correction for free-breathing assessment of left ventricular function and strain in clinical practice

“…Real-time imaging has the potential to reduce respiratory motion artifacts by acquiring data of each cardiac phase in a single shot, enables shorter breath-hold times or fully free-breathing imaging, but sacrifices spatiotemporal resolution. Compressed sensing is an emergent technique playing a pivotal role in CMR acquisition acceleration comprehensively, covering cine imaging (10,11), late gadolinium enhancement imaging (12,13), and magnetic resonance (MR) angiography (14,15). Recently, real-time cine imaging with compressed sensing (RTCSCine) was used to acquire cine images during free breathing.…”