Coronary Magnetic Resonance Angiography Research Articles

Tumors of the right atrium and the inferior vena cava operated in deep hypothermic circulatory arrest.

<b>Introduction:</b> Tumors which most frequently metastasize to the heart include: malignant melanoma, lung cancer, breast cancer, ovarian cancer, kidney cancer, leukemia, lymphomas and esophageal cancer. <br><b>Purpose:</b> The purpose of this paper was clinical analysis of a group of patients operated in deep hypothermic circulatory arrest due to tumors of the right atrium and the inferior vena cava. <br><b>Material and method:</b> The study covered 7 patients operated at the Cardiac Surgery Clinic with a cardiac tumor diagnosed on the basis of an echocardiographic assessment in the years 2012-2019. Before qualifying for surgical treatment, each patient underwent: thorough interview and physical examination, 12-lead ECG, laboratory tests and echocardiography. Patients additionally underwent: computed tomography of the chest or abdomen, magnetic resonance imaging and coronary angiography on the basis of which patients with significant coronary artery changes underwent simultaneous coronary artery bypass graft. After preparation, the tumor was excised from the vena cava and right atrium with simultaneous removal of the primary tumor, most often kidney cancer. Early and distant results of treatment were analyzed in the examined group of patients to determine the following endpoints: hospital mortality and survival after surgery: after 3 months and 12 months. <br><b>Results:</b> Of all operated patients: 2 individuals died in the early postoperative period due to hemorrhagic complications (hospital mortality - 28.6%), and 5 patients (71.4%) were discharged from the Clinic in a good general condition. In total, 3-month survival was 71.4%, and 12-month survival amounted to 28.6%. <br><b>Conclusions:</b> Surgeries are very complex and challenging, and usually take on average 8-10 hours. It can improve the outcomes of palliative oncological treatment, better physical function (cardiovascular fitness) and extend life from several months to several years in more than ²/3 patients.

Feasibility of Non-contrast-enhanced Coronary Magnetic Resonance Angiography at 3.0T

Objective To evaluate the feasibility of non-contrast-enhanced magnetic resonance angiography (NCE-MRA) on a 3.0T scanner. Methods Totally 36 volunteers and 24 patients with clinically suspected coronary artery disease underwent NCE-MRA. The quality of the NCE-MRA images was graded for each segment on a four-point scale. The subjects were divided into two groups according to image quality. The age,body mass index (BMI),heart rate,end-expiratory diaphragm displacement,and respiratory diaphragm motion amplitude were evaluated and compared. Results The average image quality score of every segment was above 2 points. The proximal and middle segments of left anterior descending artery had significantly higher quality scores than the distal segments (P=0.000) and the proximal segment of left circumflex coronary artery had significantly higher quality scores than the distal segments (P=0.000),the proximal segment of right coronary artery also had a significant higher quality score than its distal segment (P=0.001). The image quality was good in 38 subjects (64.4%). The heart rate [(66.35±9.39) beat/min vs. (75.32±11.67) beat/min] (P=0.002) and the body mass index [(24.72±3.33) kg/m 2 vs. (27.82±3.61) kg/m 2] (P=0.002) were significantly different between the good image quality group and the poor image quality group. The end-expiratory diaphragm displacement in good image quality group was (4.43±2.07)mm,which was significantly lower than that in poor image quality group [(9.26±7.62)mm](P=0.013). The respiratory diaphragm motion amplitude [(21.35±6.02) mm] in good image quality group was significantly lower than that in poor image quality group [(30.68±14.20)mm](P=0.012). Conclusion NCE-MRA on 3.0T is a feasible tool for visualization of the proximal and middle segments of coronary arteries,and the image quality can be optimized by controlling heart rate and respiration in the future.

A multi-scale variational neural network for accelerating motion-compensated whole-heart 3D coronary MR angiography

PurposeTo enable fast reconstruction of undersampled motion-compensated whole-heart 3D coronary magnetic resonance angiography (CMRA) by learning a multi-scale variational neural network (MS-VNN) which allows the acquisition of high-quality 1.2 × 1.2 × 1.2 mm isotropic volumes in a short and predictable scan time. MethodsEighteen healthy subjects and one patient underwent free-breathing 3D CMRA acquisition with variable density spiral-like Cartesian sampling, combined with 2D image navigators for translational motion estimation/compensation. The proposed MS-VNN learns two sets of kernels and activation functions for the magnitude and phase images of the complex-valued data. For the magnitude, a multi-scale approach is applied to better capture the small calibre of the coronaries. Ten subjects were considered for training and validation. Prospectively undersampled motion-compensated data with 5-fold and 9-fold accelerations, from the remaining 9 subjects, were used to evaluate the framework. The proposed approach was compared to Wavelet-based compressed-sensing (CS), conventional VNN, and to an additional fully-sampled (FS) scan. ResultsThe average acquisition time (m:s) was 4:11 for 5-fold, 2:34 for 9-fold acceleration and 18:55 for fully-sampled. Reconstruction time with the proposed MS-VNN was ~14 s. The proposed MS-VNN achieves higher image quality than CS and VNN reconstructions, with quantitative right coronary artery sharpness (CS:43.0%, VNN:43.9%, MS-VNN:47.0%, FS:50.67%) and vessel length (CS:7.4 cm, VNN:7.7 cm, MS-VNN:8.8 cm, FS:9.1 cm) comparable to the FS scan. ConclusionThe proposed MS-VNN enables 5-fold and 9-fold undersampled CMRA acquisitions with comparable image quality that the corresponding fully-sampled scan. The proposed framework achieves extremely fast reconstruction time and does not require tuning of regularization parameters, offering easy integration into clinical workflow.

Applying Nitroglycerin at Coronary MR Angiography at 1.5 T: Diagnostic Performance of Coronary Vasodilation in Patients with Coronary Artery Disease.

To evaluate the influence of applying nitroglycerin (NTG) on detecting significant coronary artery disease (CAD) and NTG-induced coronary vasodilation using coronary MR angiography in patients suspected of having CAD. In this prospective study conducted from November 2017 to September 2018, 70 consecutive participants suspected of having CAD were recruited. Of those, 57 patients successfully underwent pre- and post-NTG coronary MR angiography, both of which were performed during the end-systolic phase of the cardiac cycle. Significant coronary stenosis was defined at x-ray coronary angiography as stenosis of 50% or more. Participants were divided into a significant CAD group (significant stenosis) and nonsignificant CAD group (no significant stenosis) based on x-ray coronary angiography. Paired and unpaired Student t, generalized linear mixed model, and McNemar tests were used. The diagnostic performance of coronary MR angiography was significantly improved after NTG (P < .001). Per-patient for coronary MR angiography, from before to after NTG, respectively, the sensitivity was 97.6% (95% confidence interval [CI]: 85.6%, 99.9%) to 97.6% (95% CI: 85.6%, 99.9%), specificity was 25.0% (95% CI: 8.3%, 52.5%) to 62.5% (95% CI: 35.9%, 83.7%), positive predictive value was 76.9% (95% CI: 62.8%, 87.0%) to 87.0% (95% CI: 73.0%, 94.6%), negative predictive value was 80.0% (95% CI: 29.9%, 98.9%) to 90.9% (95% CI: 57.1%, 99.5%), and accuracy was 77.2% (95% CI: 66.3%, 88.1%) to 87.7% (95% CI: 79.2%, 96.3%). The NTG-induced coronary vasodilation was significantly lower in the significant CAD group compared with the nonsignificant CAD group. Administration of NTG significantly improved the diagnostic performance of coronary MR angiography for detecting significant CAD; however, NTG-induced coronary vasodilation was impaired in patients with significant CAD.© RSNA, 2020See also commentary by François in this issue.

Free-running 5D coronary MR angiography at 1.5T using LIBRE water excitation pulses.

To implement, optimize, and characterize lipid-insensitive binomial off-resonant RF excitation (LIBRE) pulses for fat-suppressed fully self-gated free-running 5D cardiac MRI. Bloch equation simulations were used to optimize LIBRE parameter settings in non-interrupted bSSFP prior to in vitro validation. Thus, optimized LIBRE pulses were subsequently applied to free-running coronary MRA in 20 human adult subjects, where resulting images were quantitatively compared to those obtained with non-fat-suppressing excitation (SP), conventional 1-2-1 water excitation (WE), and a previously published interrupted free-running (IFR) sequence. SAR and scan times were recorded. Respiratory-and-cardiac-motion-resolved images were reconstructed with XD-GRASP, and contrast ratios, coronary artery detection rate, vessel length, and vessel sharpness were computed. The numerically optimized LIBRE parameters were successfully validated in vitro. In vivo, LIBRE had the lowest SAR and a scan time that was similar to that of WE yet 18% shorter than that of IFR. LIBRE improved blood-fat contrast when compared to SP, WE, and IFR, vessel detection relative to SP and IFR, and vessel sharpness when compared to WE and IFR (for example, for the left main and anterior descending coronary artery, 51.5% ± 10.2% [LIBRE] versus 42.1% ± 6.8% [IFR]). Vessel length measurements remained unchanged for all investigated methods. LIBRE enabled fully self-gated non-interrupted free-running 5D bSSFP imaging of the heart at 1.5T with suppressed fat signal. Measures of image quality, vessel conspicuity, and scan time compared favorably to those obtained with the more conventional non-interrupted WE and the previously published IFR, while SAR reduction offers added flexibility.

Effects of Deep Learning Reconstruction Technique in High-Resolution Non-contrast Magnetic Resonance Coronary Angiography at a 3-Tesla Machine

To evaluate the effects of deep learning reconstruction (DLR) in qualitative and quantitative image quality of non-contrast magnetic resonance coronary angiography (MRCA). Ten healthy volunteers underwent conventional MRCA (C-MRCA) and high-resolution (HR) MRCA on a 3T magnetic resonance imaging with a voxel size of 1.8 × 1.1 × 1.7 mm3 and 1.8 × 0.6 × 1.0 mm3, respectively, for C-MRCA and HR-MRCA. High-resolution magnetic resonance coronary angiography was also reconstructed with the DLR technique (DLR-HR-MRCA). We compared the contrast-to-noise ratio (CNR) and visual evaluation scores for vessel sharpness and traceability of proximal and distal coronary vessels on a 4-point scale among 3 image series. The vascular CNR value on the C-MRCA and the DLR-HR-MRCA was significantly higher than that on the HR-MRCA in the proximal and distal coronary arteries (13.9 ± 6.4, 11.3 ± 4.4, and 7.8 ± 2.6 for C-MRCA, DLR-HR-MRCA, and HR-MRCA, P < .05, respectively). Mean visual evaluation scores for the vessel sharpness and traceability of proximal and distal coronary vessels were significantly higher on the HR-DLR-MRCA than the C-MRCA (P < .05, respectively). Deep learning reconstruction significantly improved the CNR of coronary arteries on HR-MRCA, resulting in both higher visual image quality and better vessel traceability compared with C-MRCA.

Reconstruction of undersampled 3D non-Cartesian image-based navigators for coronary MRA using an unrolled deep learning model.

To rapidly reconstruct undersampled 3D non-Cartesian image-based navigators (iNAVs) using an unrolled deep learning (DL) model, enabling nonrigid motion correction in coronary magnetic resonance angiography (CMRA). An end-to-end unrolled network is trained to reconstruct beat-to-beat 3D iNAVs acquired during a CMRA sequence. The unrolled model incorporates a nonuniform FFT operator in TensorFlow to perform the data-consistency operation, and the regularization term is learned by a convolutional neural network (CNN) based on the proximal gradient descent algorithm. The training set includes 6,000 3D iNAVs acquired from 7 different subjects and 11 scans using a variable-density (VD) cones trajectory. For testing, 3D iNAVs from 4 additional subjects are reconstructed using the unrolled model. To validate reconstruction accuracy, global and localized motion estimates from DL model-based 3D iNAVs are compared with those extracted from 3D iNAVs reconstructed with -ESPIRiT. Then, the high-resolution coronary MRA images motion corrected with autofocusing using the -ESPIRiT and DL model-based 3D iNAVs are assessed for differences. 3D iNAVs reconstructed using the DL model-based approach and conventional -ESPIRiT generate similar global and localized motion estimates and provide equivalent coronary image quality. Reconstruction with the unrolled network completes in a fraction of the time compared to CPU and GPU implementations of -ESPIRiT (20× and 3× speed increases, respectively). We have developed a deep neural network architecture to reconstruct undersampled 3D non-Cartesian VD cones iNAVs. Our approach decreases reconstruction time for 3D iNAVs, while preserving the accuracy of nonrigid motion information offered by them for correction.

3D whole-heart isotropic sub-millimeter resolution coronary magnetic resonance angiography with non-rigid motion-compensated PROST

BackgroundTo enable free-breathing whole-heart sub-millimeter resolution coronary magnetic resonance angiography (CMRA) in a clinically feasible scan time by combining low-rank patch-based undersampled reconstruction (3D-PROST) with a highly accelerated non-rigid motion correction framework.MethodsNon-rigid motion corrected CMRA combined with 2D image-based navigators has been previously proposed to enable 100% respiratory scan efficiency in modestly undersampled acquisitions. Achieving sub-millimeter isotropic resolution with such techniques still requires prohibitively long acquisition times. We propose to combine 3D-PROST reconstruction with a highly accelerated non-rigid motion correction framework to achieve sub-millimeter resolution CMRA in less than 10 min. Ten healthy subjects and eight patients with suspected coronary artery disease underwent 4–5-fold accelerated free-breathing whole-heart CMRA with 0.9 mm3 isotropic resolution. Vessel sharpness, vessel length and image quality obtained with the proposed non-rigid (NR) PROST approach were compared against translational correction only (TC-PROST) and a previously proposed NR motion-compensated technique (non-rigid SENSE) in healthy subjects. For the patient study, image quality scoring and visual comparison with coronary computed tomography angiography (CCTA) were performed.ResultsAverage scan times [min:s] were 6:01 ± 0:59 (healthy subjects) and 8:29 ± 1:41 (patients). In healthy subjects, vessel sharpness of the left anterior descending (LAD) and right (RCA) coronary arteries were improved with the proposed non-rigid PROST (LAD: 51.2 ± 8.8%, RCA: 61.2 ± 9.1%) in comparison to TC-PROST (LAD: 43.8 ± 5.1%, P = 0.051, RCA: 54.3 ± 8.3%, P = 0.218) and non-rigid SENSE (LAD: 46.1 ± 5.8%, P = 0.223, RCA: 56.7 ± 9.6%, P = 0.50), although differences were not statistically significant. The average visual image quality score was significantly higher for NR-PROST (LAD: 3.2 ± 0.6, RCA: 3.3 ± 0.7) compared with TC-PROST (LAD: 2.1 ± 0.6, P = 0.018, RCA: 2.0 ± 0.7, P = 0.014) and non-rigid SENSE (LAD: 2.3 ± 0.5, P = 0.008, RCA: 2.5 ± 0.7, P = 0.016). In patients, the proposed approach showed good delineation of the coronaries, in agreement with CCTA, with image quality scores and vessel sharpness similar to that of healthy subjects.ConclusionsWe demonstrate the feasibility of combining high undersampling factors with non-rigid motion-compensated reconstruction to obtain high-quality sub-millimeter isotropic CMRA images in ~ 8 min. Validation in a larger cohort of patients with coronary artery disease is now warranted.

Diagnostic Accuracy of Three-Dimensional Whole-Heart Magnetic Resonance Angiography to Detect Coronary Artery Disease with Invasive Coronary Angiography as a Reference: A Meta-Analysis

Objective: We aimed to evaluate the diagnostic performance of three-dimensional whole-heart magnetic resonance coronary angiography (MRCA) in detecting coronary artery disease (CAD) with invasive coronary angiography as the reference standard. Methods: We searched PubMed and Embase for studies evaluating the diagnostic performance of three-dimensional whole-heart MRCA for the diagnosis of CAD with invasive coronary angiography as the reference standard. The bivariate mixed-effects regression model was applied to synthesize available data. The clinical utility of whole-heart MRCA was calculated by the posttest probability based on Bayes’s theorem. Results: Eighteen studies were included, of which 16 provided data at the artery level. Patient-based analysis revealed a pooled sensitivity of 0.90 (95% confidence interval [CI] 0.87–0.93) and specificity of 0.79 (95% CI 0.73–0.84), while the pooled estimates were 0.86 (95% CI 0.82–0.89) and 0.89 (95% CI 0.84–0.92), respectively, at the artery level. The areas under the summary receiver operating characteristic curve were 0.93 (95% CI 0.90–0.95) and 0.92 (95% CI 0.90–0.94) at the patient and artery levels, respectively. With a pretest probability of 50%, the patients’ posttest probabilities of CAD were 81% for positive results and 11% for negative results. Conclusions: Whole-heart MRCA can be an alternative noninvasive method for diagnosis and assessment of CAD.

A direct comparison of 3\u2009T contrast-enhanced whole-heart coronary cardiovascular magnetic resonance angiography to dual-source computed tomography angiography for detection of coronary artery stenosis: a single-center experience

BackgroundIn recent years, substantial advances have been made in noninvasive cardiac imaging, including cardiac computed tomography (CT) and cardiovascular magnetic resonance (CMR). The purpose of this study was to prospectively compare the diagnostic performance of contrast-enhanced whole heart coronary CMR angiography (CCMRA) to dual-source coronary CT angiography (CCTA) for the diagnosis of significant coronary stenoses (≥50%) in patients with known or suspected coronary artery disease (CAD) referred for conventional x-ray coronary angiography.MethodsOur objective was to directly compare the diagnostic accuracy of contrast-enhanced whole-heart CCMRA (CE-CCMRA) to dual-source CCTA (DS-CCTA) for the detection of CAD. We prospectively studied 57 symptomatic patients with suspected or known CAD who were scheduled for conventional x-ray coronary angiography. Significant CAD was defined as an x-ray defined diameter reduction of ≥50% in a coronary artery with a reference diameter of ≥1.5 mm.ResultsCE-CCMRA and DS-CCTA were completed in 51 (89%) of 57 patients without complications. The acquisition times of CE-CCMRA and DS-CCTA, respectively, were 9.5 ± 3.1 min and 8.3 ± 1.4 s. On patient-based analysis, the sensitivity, specificity, positive and negative predictive value of CE-CCMRA and DS-CCTA were 93.5% versus 93.5%(P > 0.05), 85% versus 90%(P > 0.05), 90.6% versus 93.5%(P > 0.05), and 89.4% versus 90%(P > 0.05), respectively. The area under the curve (AUC) was 0.89 (95% CI: 0.79 to 0.99) for CE-CCMRA and 0.92 (95% CI: 0.83 to 1.00) for DS-CCTA.ConclusionsDS-CCTA was found to be superior to CE-CCMRA in the diagnosis of significant coronary stenoses (≥50%) in patients with suspected or known CAD scheduled for conventional x-ray coronary angiography, owing to shorter scanning times and higher spatial resolution. However, CE-CCMRA and DS-CCTA have similar diagnostic accuracies.

Feasibility of contrast-enhanced coronary artery magnetic resonance angiography using compressed sensing

BackgroundCoronary magnetic resonance angiography (CMRA) is a promising technique for assessing the coronary arteries. However, a disadvantage of CMRA is the comparatively long acquisition time. Compressed sensing (CS) can considerably reduce the scan time. The aim of this study was to verify the feasibility of CS CMRA scanning during the waiting time between contrast injection and late gadolinium enhancement (LGE) scan in a clinical protocol.MethodsFifty clinical patients underwent contrast-enhanced CS CMRA and conventional CMRA on a 3 T CMR scanner. After contrast injection, CS CMRA was scanned during the waiting time for LGE CMR. A conventional CMRA scan was performed after LGE CMR. We assessed acquisition times and coronary artery image quality for each segment on a 4-point scale. Visible vessel length, sharpness and diameter of right (RCA), left anterior descending (LAD), and left circumflex (LCX) coronary arteries were also quantitatively compared among the scans.ResultsAll CS CMRA scans were successfully performed within the LGE waiting time. The median total scan time was 207 s (163, 259 s) for CS and 785 s (698, 975 s) for conventional CMRA (p < 0.001). No significant differences were observed in image quality scores, vessel length measurements, sharpness, and diameter between CS and conventional CMRA.ConclusionsWe could achieve all CS CMRA scans within the LGE waiting time. Contrast-enhanced CS CMRA could considerably shorten the scan time while maintaining image quality compared with conventional CMRA.

A quantitative comparison between a navigated Cartesian and a self-navigated radial protocol from clinical studies for free-breathing 3D whole-heart bSSFP coronary MRA.

Navigator-gated 3D bSSFP whole-heart coronary MRA has been evaluated in several large studies including a multi-center trial. Patient studies have also been performed with more recent self-navigated techniques. In this study, these two approaches are compared side-by-side using a Cartesian navigator-gated and corrected (CNG) and a 3D radial self-navigated (RSN) protocol from published patient studies. Sixteen healthy subjects were examined with both sequences on a 1.5T scanner. Assessment of the visibility of coronary ostia and quantitative comparisons of acquisition times, blood pool homogeneity, and visible length and sharpness of the right coronary artery (RCA) and the combined left main (LM)+left anterior descending (LAD) coronary arteries were performed. Paired sample t-tests with P < .05 considered statistically significant were used for all comparisons. The acquisition time was 5:40 ± 0:28 min (mean ± SD) for RSN, being significantly shorter than the 16:59 ± 5:05 min of CNG (P < .001). RSN images showed higher blood pool homogeneity (P < .001). All coronary ostia were visible with both techniques. CNG provided significantly higher vessel sharpness in the RCA (CNG: 50.0 ± 8.6%, RSN: 34.2 ± 6.9%, P < .001) and the LM+LAD (CNG: 48.7 ± 6.7%, RSN: 32.3 ± 7.1%, P < .001). The visible vessel length was significantly longer in the LM+LAD using CNG (CNG: 9.8 ± 2.7 cm, RSN: 8.5 ± 2.6 cm, P < .05) but not in the RCA (CNG: 9.7 ± 2.3 cm, RSN: 9.3 ± 2.9 cm, P = .29). CNG provided superior vessel sharpness and might hence be the better option for examining coronary lumina. However, its blood pool inhomogeneity and prolonged and unpredictable acquisition times compared to RSN may make clinical adoption more challenging.

Three-Dimensional Free-Breathing Whole-Heart Coronary Magnetic Resonance Angiography at 1.5 T: Gadobutrol-Enhanced Gradient-Echo Acquisition Sequence Versus Non-Contrast-Enhanced Steady-State Free Precession Sequence.

The objective of this study was to compare gadobutrol-enhanced gradient-echo sequence (GRE) acquisition with T2-prepared non-contrast-enhanced steady-state free precession (SSFP) in coronary magnetic resonance angiography at 1.5 T. Twenty-one subjects successfully completed GRE and SSFP acquisition. Signal-to-noise ratio (SNR), contrast-to-noise ratio, image quality, sharpness, visibility, length, and lumen diameter of vessels were analyzed by 2 experienced radiologists. The SNR at whole left circumflex artery, left main artery, and proximal left descending artery (LAD) was significantly higher in SSFP acquisition (P < 0.05). The SNR of distal LAD was slightly higher in GRE acquisition (P < 0.05). The contrast-to-noise ratio at distal LAD, proximal and distal RCA were significantly higher with GRE acquisition (P < 0.05). Double-dose gadobutrol-enhanced GRE and unenhanced SSFP coronary magnetic resonance angiography at 1.5 T have their own characteristics, and the combined use of the 2 methods may be taken into consideration.

Improving Image Resolution of Whole-Heart Coronary MRA Using Convolutional Neural Network.

Whole-heart coronary magnetic resonance angiography (WHCMRA) permits the noninvasive assessment of coronary artery disease without radiation exposure. However, the image resolution of WHCMRA is limited. Recently, convolutional neural networks (CNNs) have obtained increased interest as a method for improving the resolution of medical images. The purpose of this study is to improve the resolution of WHCMRA images using a CNN. Free-breathing WHCMRA images with 512 × 512 pixels (pixel size = 0.65mm) were acquired in 80 patients with known or suspected coronary artery disease using a 1.5T magnetic resonance (MR) system with 32 channel coils. A CNN model was optimized by evaluating CNNs with different structures. The proposed CNN model was trained based on the relationship of signal patterns between low-resolution patches (small regions) and the corresponding high-resolution patches using a training dataset collected from 40 patients. Images with 512 × 512pixels were restored from 256 × 256 down-sampled WHCMRA images (pixel size = 1.3mm) with three different approaches: the proposed CNN, bicubic interpolation (BCI), and the previously reported super-resolution CNN (SRCNN). High-resolution WHCMRA images obtained using the proposed CNN model were significantly better than those of BCI and SRCNN in terms of root mean squared error, peak signal to noise ratio, and structure similarity index measure with respect to the original WHCMRA images. The proposed CNN approach can provide high-resolution WHCMRA images with better accuracy than BCI and SRCNN. The high-resolution WHCMRA obtained using the proposed CNN model will be useful for identifying coronary artery disease.

Velocity Encoded Cine Imaging of Mitral Valve Inflow: A novel method to determine cardiac rest periods in coronary magnetic resonance imaging

Purpose: Dual Phase Whole Heart Coronary Magnetic Resonance Angiography (CMRA) has become an invaluable addition in the evaluation of patients with congenital heart disease (CHD), as it defines detailed cardiac morphology and coronary anatomy. Image acquisition is usually performed during the cardiac rest periods, at end-systole and mid-diastole, in order to minimize cardiac motion and thus increase image sharpness. The rest periods are traditionally assessed visually using a high-temporal resolution balanced steady-state free precession (SSFP) 4-chamber (4CH) image, but this technique is limited by significant inter-observer variability. We propose that velocity encoded cine imaging of the mitral valve inflow (MVI) is a novel and more reproducible approach to determine …

An automated approach to fully self-gated free-running cardiac and respiratory motion-resolved 5D whole-heart MRI.

To develop a previously reported, electrocardiogram (ECG)-gated, motion-resolved 5D compressed sensing whole-heart sparse MRI methodology into an automated, optimized, and fully self-gated free-running framework in which external gating or triggering devices are no longer needed. Cardiac and respiratory self-gating signals were extracted from raw image data acquired in 12 healthy adult volunteers with a non-ECG-triggered 3D radial golden-angle 1.5T balanced SSFP sequence. To extract cardiac self-gating signals, central k-space coefficient signal analysis (k0 modulation), as well as independent and principal component analyses were performed on selected k-space profiles. The procedure yielding triggers with the smallest deviation from those of the reference ECG was selected for the automated protocol. Thus, optimized cardiac and respiratory self-gating signals were used for binning in a compressed sensing reconstruction pipeline. Coronary vessel length and sharpness of the resultant 5D images were compared with image reconstructions obtained with ECG-gating. Principal component analysis-derived cardiac self-gating triggers yielded a smaller deviation ( ) from the reference ECG counterparts than k0 modulation ( ) or independent component analysis ( ). Cardiac and respiratory motion-resolved 5D images were successfully reconstructed with the automated and fully self-gated approach. No significant difference was found for coronary vessel length and sharpness between images reconstructed with the fully self-gated and the ECG-gated approach (all ). Motion-resolved 5D compressed sensing whole-heart sparse MRI has successfully been developed into an automated, optimized, and fully self-gated free-running framework in which external gating, triggering devices, or navigators are no longer mandatory. The resultant coronary MRA image quality was equivalent to that obtained with conventional ECG-gating.

Multi-contrast imaging information of coronary artery wall based on magnetic resonance angiography

In order to explore the most suitable image acquisition method for coronary artery wall, the display ability and image quality of segmentation breath-holding target volume acquisition method (the breath-holding method) and real-time navigation whole-hearted acquisition method (the navigation method) of coronary artery magnetic resonance angiography (CMRA) were compared. 26 healthy volunteers were selected to accept the CMRA in 1.5 tunnels magneto-resistance (TMR) equipment by the 2 acquisition methods respectively. The arteries were divided into 9 segments according to the standards of the American Heart Association (AHA). The images were evaluated by 2 magnetic resonance physicians. Satisfaction rate and success rate of each segment of the coronary artery were counted. The results showed that the signal to noise ratio (SNR) and the carrier to noise ratio (CNR) of the images obtained by the breath-holding method were higher than those obtained by the navigation method (P<0.05). Therefore, the segmentation breath-holding target volume acquisition method is proved to have a higher image quality and the simpler and more convenient operations, which is more suitable for the acquisition of positioning images of CMRA.

Coronary vessel wall visualization via three-dimensional turbo spin-echo black blood imaging in Kawasaki disease

PurposeTo evaluate the feasibility of coronary vessel wall visualization using three-dimensional turbo spin-echo black blood imaging (3D-TSE) in children with Kawasaki disease. Materials and methodsNine patients (6 girls and 3 boys; mean age ± standard deviation, 5.6 ± 3.3 years; range, 1.4–10.3 years) were included. Coronary magnetic resonance angiography (MRA) with an axial slice orientation and 3D-TSE with axial and sagittal slice orientations (3D-TSE-axi and 3D-TSE-sag) were acquired for the whole heart. Coronary vessel walls were evaluated separately in aneurysm and normal-proximal regions. The internal diameter and wall thickness of the reformatted cross-sectional images were measured in both the regions. Reproducibility between MRA and 3D-TSE was evaluated via interclass correlation coefficients (ICCs) and Bland-Altman plots. ResultsIn total, 164 points (aneurysmal regions, 73; normal-proximal regions, 64; normal-distal regions, 27) were evaluated. The ICC for 3D-TSE-axi was higher than that for 3D-TSE-sag (aneurysmal regions, ICC = 0.88 and 0.81; normal-proximal regions, ICC = 0.90 and 0.32, respectively). Bland-Altman plots of the internal diameter via MRA and 3D-TSE-axi showed a wide 95% limit of agreement (−0.13 to 2.89 mm) and significant fixed and proportional biases (P < 0.001 and P = 0.002) in the aneurysmal regions. However, the 95% limit of agreement was narrow (−0.14 to 0.57 mm) in the normal-proximal regions. If 1 mm was set as the cut-off for a thickened wall, wall thickness via 3D-TSE-axi was found to be abnormal across many points (84.0% of aneurysmal regions; 18.4% of normal-proximal regions). Conclusions3D-TSE imaging of the normal-proximal regions of the coronary vessel in individuals with Kawasaki disease was found to be feasible. However, in aneurysmal regions, larger aneurysmal diameters led to an increased bias between MRA and 3D-TSE.

Discovery of biomarkers for the presence and progression of left ventricular diastolic dysfunction and HEart faiLure with Preserved ejection Fraction in patients at risk for cardiovascular disease: rationale and design of the HELPFul case-cohort study in a Dutch cardiology outpatient clinic

IntroductionLeft ventricular diastolic dysfunction (LVDD) is a common condition in both sexes that may deteriorate into heart failure (HF) with preserved ejection fraction (pEF), although this seems to happen more...

Motion corrected water/fat whole-heart coronary MR angiography with 100% respiratory efficiency.

PurposeTo develop a framework for respiratory motion‐corrected 3D whole‐heart water/fat coronary MR angiography (CMRA) at 3T with reduced and predictable scan time.MethodsA 3D dual‐echo acquisition and respiratory motion‐corrected reconstruction framework for water/fat CMRA imaging was developed. The acquisition sequence integrates a 2D dual‐echo image navigator (iNAV), enabling 100% respiratory scan efficiency. Respiratory motion estimated from both the 2D iNAVs and the 3D data itself is used to produce nonrigid motion‐corrected water/fat CMRA images. A first study to investigate which iNAV (water, fat, in‐phase or out‐of‐phase) provides the best translational motion estimation was performed in 10 healthy subjects. Subsequently, nonrigid motion‐corrected water/fat images were compared to a diaphragmatic navigator gated and tracked water/fat CMRA acquisition. Image quality metrics included visible vessel length and vessel sharpness for both the left anterior descending and right coronary arteries.ResultsAverage vessel sharpness achieved with water, fat, in‐phase and out‐of‐phase iNAVs was 33.8%, 29.6%, 32.2%, and 38.5%, respectively. Out‐of‐phase iNAVs were therefore used for estimating translational respiratory motion for the remainder of the study. No statistically significant differences in vessel length and sharpness (P > 0.01) were observed between the proposed nonrigid motion correction approach and the reference images, although data acquisition was significantly shorter (P < 2.6×10–4). Motion correction improved vessel sharpness by 60.4% and vessel length by 47.7%, on average, in water CMRA images in comparison with no motion correction.ConclusionThe feasibility of a novel motion‐corrected water/fat CMRA approach has been demonstrated at 3T, producing images comparable to a reference gated acquisition, but in a shorter and predictable scan time.