Diagnostic performance of image navigated coronary CMR angiography in patients with coronary artery disease

Self-navigated coronary MR angiography for coronary aneurysm detection in Kawasaki disease at 3T: comparison with conventional diaphragm-navigated coronary MR angiography

OBJECTIVES

To assess the scan time, image quality, and diagnostic performance of self-navigated coronary MR angiography (SN-CMRA) for coronary aneurysm (CAA) detection in Kawasaki disease (KD) patients and compare it with diaphragm-navigated CMRA (DN-CMRA).

MATERIALS AND METHODS

SN-CMRA and DN-CMRA were performed on 76 pediatric patients with KD (48 males, 6.75 ± 3.59 years). Thirty-three of whom underwent coronary CT angiography (CCTA)/invasive coronary angiography (ICA). The scan time and qualitative and quantitative image quality assessment were compared between the two sequences. The diagnostic performance for CAA detection by the two approaches using CCTA/ICA as the reference standard was compared on per-patient, per-vessel, and per-segment basis.

RESULTS

The scan time of SN-CMRA was significantly shorter than that of DN-CMRA (7.49 ± 2.31 min vs. 10.03 ± 4.47 min, p < 0.001). There was no difference in overall and segmental image quality to reach the clinical diagnostic criteria between the two sequences (all p > 0.05). No significant difference in vessel length of the three main coronary arteries was found between the two approaches (all p > 0.05). Moreover, SN-CMRA showed no difference from DN-CMRA in contrast ratio of blood-myocardium (1.25 (interquartile range [IQR], 1.06 to 1.51) vs. 1.18 (IQR, 0.95 to 1.64), p = 0.706). There was no difference in the diagnostic accuracy of SN-CMRA and DN-CMRA for CAA detection on per-patient, per-vessel, or per-segment basis (all p > 0.05).

CONCLUSION

SN-CMRA at 3T showed reliable diagnostic performance and application value for CAA detection in children with KD. Compared with DN-CMRA, SN-CMRA can simplify the scanning procedure and shorten the scan time, achieving comparable image quality and diagnostic accuracy.

CLINICAL RELEVANCE STATEMENT

Coronary aneurysm in children with Kawasaki disease (KD) can be detected by self-navigated coronary MR angiography (CMRA) non-invasively and without radiation, achieving comparable image quality and diagnostic performance as diaphragm-navigated CMRA while shortening scanning time. It can provide reference for risk stratification and treatment management of KD.

KEY POINTS

• Evaluating the size of coronary aneurysm is important for risk stratification and treatment of Kawasaki disease. • Self-navigated coronary MR angiography (SN-CMRA) shortens scan time and achieves comparable image quality and diagnostic performance compared with diaphragm-navigated coronary MR angiography. • SN-CMRA can evaluate coronary aneurysm non-invasively and without radiation, providing information for risk stratification and treatment.

Automated detection of cardiac rest period for trigger delay calculation for image-based navigator coronary magnetic resonance angiography

BACKGROUND

Coronary magnetic resonance angiography (coronary MRA) is increasingly being considered as a clinically viable method to investigate coronary artery disease (CAD). Accurate determination of the trigger delay to place the acquisition window within the quiescent part of the cardiac cycle is critical for coronary MRA in order to reduce cardiac motion. This is currently reliant on operator-led decision making, which can negatively affect consistency of scan acquisition. Recently developed deep learning (DL) derived software may overcome these issues by automation of cardiac rest period detection.

METHODS

Thirty individuals (female, n = 10) were investigated using a 0.9 mm isotropic image-navigator (iNAV)-based motion-corrected coronary MRA sequence. Each individual was scanned three times utilising different strategies for determination of the optimal trigger delay: (1) the DL software, (2) an experienced operator decision, and (3) a previously utilised formula for determining the trigger delay. Methodologies were compared using custom-made analysis software to assess visible coronary vessel length and coronary vessel sharpness for the entire vessel length and the first 4 cm of each vessel.

RESULTS

There was no difference in image quality between any of the methodologies for determination of the optimal trigger delay, as assessed by visible coronary vessel length, coronary vessel sharpness for each entire vessel and vessel sharpness for the first 4 cm of the left mainstem, left anterior descending or right coronary arteries. However, vessel length of the left circumflex was slightly greater using the formula method. The time taken to calculate the trigger delay was significantly lower for the DL-method as compared to the operator-led approach (106 ± 38.0 s vs 168 ± 39.2 s, p < 0.01, 95% CI of difference 25.5-98.1 s).

CONCLUSIONS

Deep learning-derived automated software can effectively and efficiently determine the optimal trigger delay for acquisition of coronary MRA and thus may simplify workflow and improve reproducibility.

Assessment of coronary microcirculation alterations in a porcine model of no-reflow using ultrasound localization microscopy: a proof of concept study

BACKGROUND

Coronary microvascular obstruction also known as no-reflow phenomenon is a major issue during myocardial infarction that bears important prognostic implications. Alterations of the microvascular network remains however challenging to assess as there is no imaging modality in the clinics that can image directly the coronary microvascular vessels. Ultrasound Localization Microscopy (ULM) imaging was recently introduced to map microvascular flows at high spatial resolution (∼10 μm). In this study, we developed an approach to image alterations of the microvascular coronary flow in ex vivo perfused swine hearts.

METHODS

A porcine model of myocardial ischemia-reperfusion was used to obtain microvascular coronary alterations and no-reflow. Four female hearts with myocardial infarction in addition to 6 controls were explanted and placed immediately in a dedicated preservation and perfusion box manufactured for ultrasound imaging. Microbubbles (MB) were injected into the vasculature to perform Ultrasound Localization Microscopy (ULM) imaging and a linear ultrasound probe mounted on a motorized device was used to scan the heart on multiple slices. The coronary microvascular anatomy and flow velocity was reconstructed using dedicated ULM algorithms and analyzed quantitatively.

FINDINGS

We were able to image the coronary microcirculation of ex vivo swine hearts at a resolution of tens of microns and measure flow velocities ranging from 10 mm/s in arterioles up to more than 200 mm/s in epicardial arteries. Under different aortic perfusion pressures, we measured in large arteries of a subset of control hearts an increase of flow velocity from 31 ± 11 mm/s at 87 mmHg to 47 ± 17 mm/s at 132 mmHg (N = 3 hearts, P < 0.05). This increase was compared with a control measurement with a flowmeter in the aorta. We also compared 6 control hearts to 4 hearts in which no-reflow was induced by the occlusion and reperfusion of a coronary artery. Using average MB velocity and average density of MB per unit of surface as two ULM quantitative markers of perfusion, we were able to detect areas of coronary no-reflow in good agreement with a control anatomical pathology analysis of the cardiac tissue. In the no-reflow zone, we measured an average perfusion of 204 ± 305 MB/mm2 compared to 3182 ± 1302 MB/mm2 in the surrounding re-perfused area.

INTERPRETATION

We demonstrated this approach can directly image and quantify coronary microvascular obstruction and no-reflow on large mammal perfused hearts. This is a first step for noninvasive, quantitative and affordable assessment of the coronary microcirculation function and particularly coronary microvascular anatomy in the infarcted heart. This approach has the potential to be extended to other clinical situations characterized by microvascular dysfunction.

FUNDING

This study was supported by the French National Research Agency (ANR) under ANR-21-CE19-0002 grant agreement.

Diagnostic Performance and Safety of a Novel Ferumoxytol-Enhanced Coronary Magnetic Resonance Angiography

BACKGROUND

Currently, noninvasive arteriography for the diagnosis of coronary artery disease is clinically limited to the computed tomography scanning, where patients have to be exposed to the radiation and risks associated with iodinated contrast. We aimed to investigate the diagnostic performance and safety of a novel ferumoxytol-enhanced coronary magnetic resonance angiography (CMRA) in patients with suspected coronary artery disease.

METHODS

Thirty patients, 19 males, with a median age of 63 years old, and 17 with renal insufficiency, who were scheduled for invasive coronary angiography, were enrolled. Ferumoxytol was administered intravenously with a dose of 3 mg/kg during CMRA. Images were acquired with an ECG-triggered, navigator-gated, inversion recovery-prepared 3D fast low-angle shot sequence, and the image quality was assessed by a 4-point scale. Eighteen-segment coronary artery model was adopted to evaluate the visibility of the coronary arteries, and the image quality and stenosis were evaluated in nine segments. The diagnostic performance of CMRA is described as sensitivity, specificity, positive and negative predictive values, and accuracy with the invasive coronary angiography results as reference. The patients' vital signs were monitored during CMRA, and their hepatic and renal functions were followed up for 3 months to evaluate the safety of ferumoxytol.

RESULTS

Two hundred fifty-two of the 270 study segments were identified by CMRA, and their quality score reached 3.6±0.7. Referring to the invasive coronary angiography results, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ferumoxytol-enhanced CMRA reached 100.0%, 66.7%, 92.3%, 100.0%, and 93.3% respectively in patient-based analysis; 91.4%, 90.9%, 86.5%, 94.3%, and 91.1%, respectively in vessel-based analysis; and 92.3%, 96.7%, 83.7%, 98.6%, and 96.0%, respectively in segment-based analysis. No ferumoxytol-related adverse event was observed during the 3-month follow-up.

CONCLUSIONS

Ferumoxytol-enhanced CMRA demonstrated good diagnostic performance and excellent safety in the diagnosis of significant coronary stenosis, providing an alternative to coronary computed tomography angiography for the diagnosis of coronary artery disease.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05032937.

Exercise electrocardiogram for risk-based screening of severe residual coronary lesion in children after coronary surgery

BACKGROUND

Residual severe coronary artery (CA) lesion (SCL) in children after cardiac surgery involving the CA is a major concern.

AIM

To evaluate the value of exercise electrocardiogram (eECG) for risk-based screening of SCL.

METHODS

We analysed 135 maximal eECG from 115 children (mean age 13.6±3.7 years) who underwent concomitant CA imaging. SCL was defined as a stenosis exceeding 50%.

RESULTS

Underlying congenital heart diseases were transposition of the great arteries (TGA) (n = 116), CA pathway anomaly (n = 13) and left CA from the pulmonary artery (n = 6). Eleven SCLs were identified in 10 patients, of which 3 had a known untreated non-severe lesion and 4 had no lesions on previous imaging. In multivariable analysis, risks markers for SCL were effort chest pain (OR: 4.72, 95% CI: 1.23-18.17; P=0.024), intramural pathway (OR: 4.37, 95% CI: 1.14-16.81; P=0.032). Yacoubs C-type CA was added as a risk marker for patients with TGA (P=0.0009). All patients with SCL had a positive eECG (sensitivity: 100%, 95% CI: 72-100). Specificity was 81% (95% CI: 73-87). In the low-risk group (0 risk markers), 3/95 patients had SCL (3%), and the post-test probability of SCL with positive eECG (PPr+) was 15% (95% CI: 8-21). In the high-risk group (≥1 risk marker) comprising 8/40 SCLs (20%), PPr+ was 53% (95% CI: 35-67).

CONCLUSIONS

Most SCL tended to develop gradually, years after surgery. Provided it is near maximal, a negative eECG appears sufficient to exclude SCL. In the high-risk group, PPr+ exceeded 50%.

High-resolution non-contrast free-breathing coronary cardiovascular magnetic resonance angiography for detection of coronary artery disease: validation against invasive coronary angiography

BACKGROUND

Coronary artery disease (CAD) is the single most common cause of death worldwide. Recent technological developments with coronary cardiovascular magnetic resonance angiography (CCMRA) allow high-resolution free-breathing imaging of the coronary arteries at submillimeter resolution without contrast in a predictable scan time of ~ 10 min. The objective of this study was to determine the diagnostic accuracy of high-resolution CCMRA for CAD detection against the gold standard of invasive coronary angiography (ICA).

METHODS

Forty-five patients (15 female, 62 ± 10 years) with suspected CAD underwent sub-millimeter-resolution (0.6 mm3) non-contrast CCMRA at 1.5T in this prospective clinical study from 2019-2020. Prior to CCMR, patients were given an intravenous beta blockers to optimize heart rate control and sublingual glyceryl trinitrate to promote coronary vasodilation. Obstructive CAD was defined by lesions with ≥ 50% stenosis by quantitative coronary angiography on ICA.

RESULTS

The mean duration of image acquisition was 10.4 ± 2.1 min. On a per patient analysis, the sensitivity, specificity, positive predictive value and negative predictive value (95% confidence intervals) were 95% (75-100), 54% (36-71), 60% (42-75) and 93% (70-100), respectively. On a per vessel analysis the sensitivity, specificity, positive predictive value and negative predictive value (95% confidence intervals) were 80% (63-91), 83% (77-88), 49% (36-63) and 95% (90-98), respectively.

CONCLUSION

As an important step towards clinical translation, we demonstrated a good diagnostic accuracy for CAD detection using high-resolution CCMRA, with high sensitivity and negative predictive value. The positive predictive value is moderate, and combination with CMR stress perfusion may improve the diagnostic accuracy. Future multicenter evaluation is now required.

Coronary Magnetic Resonance Angiography in Chronic Coronary Syndromes

Cardiovascular disease is the leading cause of mortality worldwide, with atherosclerotic coronary artery disease (CAD) accounting for the majority of cases. X-ray coronary angiography and computed tomography coronary angiography (CCTA) are the imaging modalities of choice for the assessment of CAD. However, the use of ionising radiation and iodinated contrast agents remain drawbacks. There is therefore a clinical need for an alternative modality for the early identification and longitudinal monitoring of CAD without these associated drawbacks. Coronary magnetic resonance angiography (CMRA) could be a potential alternative for the detection and monitoring of coronary arterial stenosis, without exposing patients to ionising radiation or iodinated contrast agents. Further advantages include its versatility, excellent soft tissue characterisation and suitability for repeat imaging. Despite the early promise of CMRA, widespread clinical utilisation remains limited due to long and unpredictable scan times, onerous scan planning, lower spatial resolution, as well as motion related image quality degradation. The past decade has brought about a resurgence in CMRA technology, with significant leaps in image acceleration, respiratory and cardiac motion estimation and advanced motion corrected or motion-resolved image reconstruction. With the advent of artificial intelligence, great advances are also seen in deep learning-based motion estimation, undersampled and super-resolution reconstruction promising further improvements of CMRA. This has enabled high spatial resolution (1 mm isotropic), 3D whole heart CMRA in a clinically feasible and reliable acquisition time of under 10 min. Furthermore, latest super-resolution image reconstruction approaches which are currently under evaluation promise acquisitions as short as 1 min. In this review, we will explore the recent technological advances that are designed to bring CMRA closer to clinical reality.

Clinical comparison of sub-mm high-resolution non-contrast coronary CMR angiography against coronary CT angiography in patients with low-intermediate risk of coronary artery disease: a single center trial

BACKGROUND

The widespread clinical application of coronary cardiovascular magnetic resonance (CMR) angiography (CMRA) for the assessment of coronary artery disease (CAD) remains limited due to low scan efficiency leading to prolonged and unpredictable acquisition times; low spatial-resolution; and residual respiratory motion artefacts resulting in limited image quality. To overcome these limitations, we have integrated highly undersampled acquisitions with image-based navigators and non-rigid motion correction to enable high resolution (sub-1 mm3) free-breathing, contrast-free 3D whole-heart coronary CMRA with 100% respiratory scan efficiency in a clinically feasible and predictable acquisition time.

OBJECTIVES

To evaluate the diagnostic performance of this coronary CMRA framework against coronary computed tomography angiography (CTA) in patients with suspected CAD.

METHODS

Consecutive patients (n = 50) with suspected CAD were examined on a 1.5T CMR scanner. We compared the diagnostic accuracy of coronary CMRA against coronary CTA for detecting a ≥ 50% reduction in luminal diameter.

RESULTS

The 50 recruited patients (55 ± 9 years, 33 male) completed coronary CMRA in 10.7 ± 1.4 min. Twelve (24%) had significant CAD on coronary CTA. Coronary CMRA obtained diagnostic image quality in 95% of all, 97% of proximal, 97% of middle and 90% of distal coronary segments. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were: per patient (100%, 74%, 55%, 100% and 80%), per vessel (81%, 88%, 46%, 97% and 88%) and per segment (76%, 95%, 44%, 99% and 94%) respectively.

CONCLUSIONS

The high diagnostic image quality and diagnostic performance of coronary CMRA compared against coronary CTA demonstrates the potential of coronary CMRA as a robust and safe non-invasive alternative for excluding significant disease in patients at low-intermediate risk of CAD.

Motion compensated whole-heart coronary cardiovascular magnetic resonance angiography using focused navigation (fNAV)

BACKGROUND

Radial self-navigated (RSN) whole-heart coronary cardiovascular magnetic resonance angiography (CCMRA) is a free-breathing technique that estimates and corrects for respiratory motion. However, RSN has been limited to a 1D rigid correction which is often insufficient for patients with complex respiratory patterns. The goal of this work is therefore to improve the robustness and quality of 3D radial CCMRA by incorporating both 3D motion information and nonrigid intra-acquisition correction of the data into a framework called focused navigation (fNAV).

METHODS

We applied fNAV to 500 data sets from a numerical simulation, 22 healthy subjects, and 549 cardiac patients. In each of these cohorts we compared fNAV to RSN and respiratory resolved extradimensional golden-angle radial sparse parallel (XD-GRASP) reconstructions of the same data. Reconstruction times for each method were recorded. Motion estimate accuracy was measured as the correlation between fNAV and ground truth for simulations, and fNAV and image registration for in vivo data. Percent vessel sharpness was measured in all simulated data sets and healthy subjects, and a subset of patients. Finally, subjective image quality analysis was performed by a blinded expert reviewer who chose the best image for each in vivo data set and scored on a Likert scale 0-4 in a subset of patients by two reviewers in consensus.

RESULTS

The reconstruction time for fNAV images was significantly higher than RSN (6.1 ± 2.1 min vs 1.4 ± 0.3, min, p < 0.025) but significantly lower than XD-GRASP (25.6 ± 7.1, min, p < 0.025). Overall, there is high correlation between the fNAV and reference displacement estimates across all data sets (0.73 ± 0.29). For simulated data, healthy subjects, and patients, fNAV lead to significantly sharper coronary arteries than all other reconstruction methods (p < 0.01). Finally, in a blinded evaluation by an expert reviewer fNAV was chosen as the best image in 444 out of 571 data sets (78%; p < 0.001) and consensus grades of fNAV images (2.6 ± 0.6) were significantly higher (p < 0.05) than uncorrected (1.7 ± 0.7), RSN (1.9 ± 0.6), and XD-GRASP (1.8 ± 0.8).

CONCLUSION

fNAV is a promising technique for improving the quality of RSN free-breathing 3D whole-heart CCMRA. This novel approach to respiratory self-navigation can derive 3D nonrigid motion estimations from an acquired 1D signal yielding statistically significant improvement in image sharpness relative to 1D translational correction as well as XD-GRASP reconstructions. Further study of the diagnostic impact of this technique is therefore warranted to evaluate its full clinical utility.

Coronary Magnetic Resonance Angiography: Technical Innovations Leading Us to the Promised Land?

Coronary artery disease remains the leading cause of cardiovascular morbidity and mortality. Invasive X-ray angiography and coronary computed tomography angiography are established gold standards for coronary luminography. However, they expose patients to invasive complications, ionizing radiation, and iodinated contrast agents. Among a number of imaging modalities, coronary cardiovascular magnetic resonance (CMR) angiography may be used in some cases as an alternative for the detection and monitoring of coronary arterial stenosis, with advantages including its versatility, excellent soft tissue characterization, and avoidance of ionizing radiation and iodinated contrast agents. In this review, we explore the recent advances in motion correction, image acceleration, and reconstruction technologies that are bringing coronary CMR angiography closer to widespread clinical implementation.

PET/MRI of atherosclerosis

Myocardial infarction and stroke are the most prevalent global causes of death. Each year 15 million people worldwide die due to myocardial infarction or stroke. Rupture of a vulnerable atherosclerotic plaque is the main underlying cause of stroke and myocardial infarction. Key features of a vulnerable plaque are inflammation, a large lipid-rich necrotic core (LRNC) with a thin or ruptured overlying fibrous cap, and intraplaque hemorrhage (IPH). Noninvasive imaging of these features could have a role in risk stratification of myocardial infarction and stroke and can potentially be utilized for treatment guidance and monitoring. The recent development of hybrid PET/MRI combining the superior soft tissue contrast of MRI with the opportunity to visualize specific plaque features using various radioactive tracers, paves the way for comprehensive plaque imaging. In this review, the use of hybrid PET/MRI for atherosclerotic plaque imaging in carotid and coronary arteries is discussed. The pros and cons of different hybrid PET/MRI systems are reviewed. The challenges in the development of PET/MRI and potential solutions are described. An overview of PET and MRI acquisition techniques for imaging of atherosclerosis including motion correction is provided, followed by a summary of vessel wall imaging PET/MRI studies in patients with carotid and coronary artery disease. Finally, the future of imaging of atherosclerosis with PET/MRI is discussed.

Quantitative imaging of coronary flows using 3D ultrafast Doppler coronary angiography

Coronary flow rate remains complex to assess in clinical practice using non-invasive, non-ionizing imaging tools. In this study, we introduce 3D ultrafast Doppler coronary angiography (3D UDCA), an ultrasound-based method to assess coronary blood flows in three-dimensions at high volume-rate and in one single heartbeat. We demonstrate that 3D UDCA can visualize the coronary vasculature with high temporal and spatial resolution and quantify the absolute flow. The feasibility of the technique was demonstrated in an open-chest swine model. The flow rate of the left-anterior descending artery (LAD) assessed by 3D UDCA was reconstructed successfully at the early diastolic and late diastolic phases and was in good agreement with an invasive gold-standard flowmeter during baseline, reactive hyperemia and coronary stenosis (r² = 0.84). Finally, we demonstrate that a coronary stenosis on the LAD can be visualized as well as its associated flow acceleration.

Cardiovascular magnetic resonance imaging for structural heart disease

Cardiovascular magnetic resonance (CMR) has increasingly become a powerful imaging technique over the past few decades due to increasing knowledge about clinical applications, operator experience and technological advances, including the introduction of high field strength magnets, leading to improved signal-to-noise ratio. Its success is attributed to the free choice of imaging planes, the wide variety of imaging techniques, and the lack of harmful radiation. Developments in CMR have led to the accurate evaluation of cardiac structure, function and tissues characterisation, so this non-invasive technique has become a powerful tool for a broad range of cardiac pathologies. This review will provide an introduction of magnetic resonance imaging (MRI) physics, an overview of the current techniques and clinical application of CMR in structural heart disease, and illustrated examples of its use in clinical practice.

Magnetic resonance imaging for pathobiological assessment and interventional treatment of the coronary arteries

X-ray-based fluoroscopy is the standard tool for diagnostics and intervention in coronary artery disease. In recent years, computed tomography has emerged as a non-invasive alternative to coronary angiography offering detection of coronary calcification and imaging of the vessel lumen by the use of iodinated contrast agents. Even though currently available invasive or non-invasive techniques can show the degree of vessel stenosis, they are unable to provide information about biofunctional plaque properties, e.g. plaque inflammation. Furthermore, the use of radiation and the necessity of iodinated contrast agents remain unfavourable prerequisites. Magnetic resonance imaging (MRI) is a radiation-free alternative to X-ray which offers anatomical and functional imaging contrasts fostering the idea of non-invasive biofunctional assessment of the coronary vessel wall. In combination with molecular contrast agents that target-specific epitopes of the vessel wall, MRI might reveal unique plaque properties rendering it, for example, ‘vulnerable and prone to rupture’. Early detection of these lesions may allow for early or prophylactic treatment even before an adverse coronary event occurs. Besides diagnostic imaging, advances in real-time image acquisition and motion compensation now provide grounds for MRI-guided coronary interventions. In this article, we summarize our research on MRI-based molecular imaging in cardiovascular disease and feature our advances towards real-time MRI-based coronary interventions in a porcine model.

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

BACKGROUND

To 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.

METHODS

Non-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.

RESULTS

Average 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.

CONCLUSIONS

We 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.

Journal of Cardiovascular Magnetic Resonance: 2017/2018 in review

There were 89 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2017, including 76 original research papers, 4 reviews, 5 technical notes, 1 guideline, and 3 corrections. The volume was down slightly from 2017 with a corresponding 15% decrease in manuscript submissions from 405 to 346 and thus reflects a slight increase in the acceptance rate from 25 to 26%. The decrease in submissions for the year followed the initiation of the increased author processing charge (APC) for Society for Cardiovascular Magnetic Resonance (SCMR) members for manuscripts submitted after June 30, 2018. The quality of the submissions continues to be high. The 2018 JCMR Impact Factor (which is published in June 2019) was slightly lower at 5.1 (vs. 5.46 for 2017; as published in June 2018. The 2018 impact factor means that on average, each JCMR published in 2016 and 2017 was cited 5.1 times in 2018. Our 5 year impact factor was 5.82.In accordance with Open-Access publishing guidelines of BMC, the JCMR articles are published on-line in a continuus fashion in the chronologic order of acceptance, with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful for the JCMR audience to annually summarize the publications into broad areas of interest or themes, so that readers can view areas of interest in a single article in relation to each other and contemporaneous JCMR publications. In this publication, the manuscripts are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought within the journal. In addition, as in the past two years, I have used this publication to also convey information regarding the editorial process and as a "State of our JCMR."This is the 12th year of JCMR as an open-access publication with BMC (formerly known as Biomed Central). The timing of the JCMR transition to the open access platform was "ahead of the curve" and a tribute to the vision of Dr. Matthias Friedrich, the SCMR Publications Committee Chair and Dr. Dudley Pennell, the JCMR editor-in-chief at the time. The open-access system has dramatically increased the reading and citation of JCMR publications and I hope that you, our authors, will continue to send your very best, high quality manuscripts to JCMR for consideration. It takes a village to run a journal and I thank our very dedicated Associate Editors, Guest Editors, Reviewers for their efforts to ensure that the review process occurs in a timely and responsible manner. These efforts have allowed the JCMR to continue as the premier journal of our field. This entire process would also not be possible without the dedication and efforts of our managing editor, Diana Gethers. Finally, I thank you for entrusting me with the editorship of the JCMR as I begin my 4th year as your editor-in-chief. It has been a tremendous experience for me and the opportunity to review manuscripts that reflect the best in our field remains a great joy and highlight of my week!

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

PURPOSE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Journal of Cardiovascular Magnetic Resonance 2017

There were 106 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2017, including 92 original research papers, 3 reviews, 9 technical notes, and 1 Position paper, 1 erratum and 1 correction. The volume was similar to 2016 despite an increase in manuscript submissions to 405 and thus reflects a slight decrease in the acceptance rate to 26.7%. The quality of the submissions continues to be high. The 2017 JCMR Impact Factor (which is published in June 2018) was minimally lower at 5.46 (vs. 5.71 for 2016; as published in June 2017), which is the second highest impact factor ever recorded for JCMR. The 2017 impact factor means that an average, each JCMR paper that were published in 2015 and 2016 was cited 5.46 times in 2017.In accordance with Open-Access publishing of Biomed Central, the JCMR articles are published on-line in continuus fashion and in the chronologic order of acceptance, with no collating of the articles into sections or special thematic issues. For this reason, over the years, the Editors have felt that it is useful to annually summarize the publications into broad areas of interest or theme, so that readers can view areas of interest in a single article in relation to each other and other contemporary JCMR articles. In this publication, the manuscripts are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought within the journal. In addition, I have elected to use this format to convey information regarding the editorial process to the readership.I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your very best, high quality manuscripts to JCMR for consideration. I thank our very dedicated Associate Editors, Guest Editors, and Reviewers for their efforts to ensure that the review process occurs in a timely and responsible manner and that the JCMR continues to be recognized as the forefront journal of our field. And finally, I thank you for entrusting me with the editorship of the JCMR as I begin my 3rd year as your editor-in-chief. It has been a tremendous learning experience for me and the opportunity to review manuscripts that reflect the best in our field remains a great joy and highlight of my week!