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OBJECTIVES: To evaluate if cine sequences accelerated by compressed sensing (CS) are feasible in clinical routine and yield equivalent cardiac morphology in less time. DESIGN: We evaluated 155 consecutive patients with various cardiac diseases scanned during our clinical routine. LV and RV short axis (SAX) cine images were acquired by conventional and prototype 2-shot CS sequences on a 1.5 T CMR. The 2-shot prototype captures the entire heart over a period of 3 beats making the acquisition potentially even faster. Both scans were performed with identical slice parameters and positions. We compared LV and RV morphology with Bland-Altmann plots and weighted the results in relation to pre-defined tolerance intervals. Subjective and objective image quality was evaluated using a 4-point score and adapted standardized criteria. Scan times were evaluated for each sequence. RESULTS: In total, no acquisitions were lost due to non-diagnostic image quality in the subjective image score. Objective image quality analysis showed no statistically significant differences. The scan time of the CS cines was significantly shorter (p < .001) with mean scan times of 178 ± 36 s compared to 313 ± 65 s for the conventional cine. All cardiac function parameters showed excellent correlation (r 0.978-0.996). Both sequences were considered equivalent for the assessment of LV and RV morphology. CONCLUSIONS: The 2-shot CS SAX cines can be used in clinical routine to acquire cardiac morphology in less time compared to the conventional method, with no total loss of acquisitions due to nondiagnostic quality. Trial registration: ISRCTN12344380. Registered 20 November 2020, retrospectively registered.

The goal of this study was to evaluate a three-dimensional compressed sensing (3D-CS) LGE prototype sequence for the detection and quantification of myocardial fibrosis in patients with chronic myocardial infarction (CMI) and myocarditis (MYC) compared with a 2D-LGE standard. Patients with left-ventricular LGE due to CMI (n = 33) or MYC (n = 20) were prospectively recruited. 2D-LGE and 3D-CS images were acquired in random order at 1.5 Tesla. 3D-CS short axis (SAX) images were reconstructed corresponding to 2D SAX images. LGE was quantitatively assessed on patient and segment level using semi-automated threshold methods. Image quality (4-point scoring system), Contrast-ratio (CR) and acquisition times were compared. There was no significant difference between 2D and 3D sequences regarding global LGE (%) (CMI [2D-LGE: 11.4 ± 7.5; 3D-LGE: 11.5 ± 8.5; p = 0.99]; MYC [2D-LGE: 27.0 ± 15.7; 3D-LGE: 26.2 ± 13.1; p = 0.70]) and segmental LGE-extent (p = 0.63). 3D-CS identified papillary infarction in 5 cases which was not present in 2D images. 2D-LGE acquisition time was shorter (2D: median: 06:59 min [IQR: 05:51–08:18]; 3D: 14:48 min [12:45–16:57]). 3D-CS obtained better quality scores (2D: 2.06 ± 0.56 vs. 3D: 2.29 ± 0.61). CR did not differ (p = 0.63) between basal and apical regions in 3D-CS images but decreased significantly in 2D apical images (CR basal: 2D: 0.77 ± 0.11, 3D: 0.59 ± 0.10; CR apical: 2D: 0.64 ± 0.17, 3D: 0.53 ± 0.11). 3D-LGE shows high congruency with standard LGE and allows better identification of small lesions. However, the current 3D-CS LGE sequence did not provide PSIR reconstruction and acquisition time was longer.

PURPOSE: Time-of-flight (TOF)-MR angiography (MRA) is an important imaging sequence for the surveillance and analysis of cerebral arteriovenous shunt (AVS), including arteriovenous malformation (AVM) and arteriovenous fistula (AVF). However, this technique has the disadvantage of a relatively long scan time. The aim of this study was to compare diagnostic accuracy between compressed sensing (CS)-TOF and conventional parallel imaging (PI)-TOF-MRA for detecting and characterizing AVS. METHODS: This study was approved by the institutional review board for human studies. Participants comprised 56 patients who underwent both CS-TOF-MRA and PI-TOF-MRA on a 3-T MR unit with or without cerebral AVS between June 2016 and September 2018. Imaging parameters for both sequences were almost identical, except the acceleration factor of 3× for PI-TOF-MRA and 6.5× for CS-TOF-MRA, and the scan time of 5min 19s for PI-TOF-MRA and 2min 26s for CS-TOF-MRA. Two neuroradiologists assessed the accuracy of AVS detection on each sequence and analyzed AVS angioarchitecture. Concordance between CS-TOF, PI-TOF, and digital subtraction angiography was calculated using unweighted and weighted kappa statistics. RESULTS: Both CS-TOF-MRA and PI-TOF-MRA yielded excellent sensitivity and specificity for detecting intracranial AVS (reviewer 1, 97.3%, 94.7%; reviewer 2, 100%, 100%, respectively). Interrater agreement on the angioarchitectural features of intracranial AVS on CS-MRA and PI-MRA was moderate to good. CONCLUSION: The diagnostic performance of CS-TOF-MRA is comparable to that of PI-TOF-MRA in detecting and classifying AVS with a reduced scan time under 2.5min.

Background and purpose Conventional cardiac magnetic resonance (CCMR) imaging is usually performed with breath-holding (BH), which is adverse in patients with BH limitations. We explored the ability of a free-breathing CMR (fCMR) protocol to prognosticate in patients with coronary heart diseases (CHD) and limited BH ability. Methods Sixty-seven patients with CHD and limited BH abilities were prospectively enrolled in this study. All patients underwent comprehensive fCMR imaging at 3.0 T. The fCMR protocols included compressed sensing (CS) single-shot cine acceleration imaging, and motion-corrected (MOCO), single-shot late gadolinium enhancement (LGE) imaging. Image quality (IQ) of the cine and LGE images was evaluated based on the 5-point Likert scale. The value of fMRI in providing a prognosis in patients with CHD was assessed. Statistical methods included the T test, Mann–Whitney test, Kappa test, Kaplan–Meier curve, Log-rank test, Cox proportional hazard regression analysis, and receiver operating characteristic curves. Results All IQ scores of the short axis CS-cine and both the short and long axes MOCO LGE images were ≥ 3 points. Over a median follow-up of 31 months (range 3.8–38.2), 25 major adverse cardiovascular events (MACE) occurred. In the univariate analysis, infarction size (IS), left ventricular ejection fraction (LVEF), 3D-Global peak longitudinal strain (3D-GPLS), heart failure classification were significantly associated with MACE. When the significantly univariate MACE predictors, added to the multivariate analysis, which showed IS (HR 1.02; 95% CI 1.00–1.05; p = 0.048) and heart failure with preserved EF (HR 0.20; 95% CI 0.04–0.98; p = 0.048) correlated positively with MACE. The optimal cutoff value for LVEF, 3D-GPLS, and IS in predicting MACE was 34.2%, − 5.7%, and 26.1% respectively, with a sensitivity of 90.5%, 64%, and 96.0% and specificity of 72%, 95.2%, and 85.7% respectively. Conclusions The fCMR protocol can be used to make prognostic assessments in patients with CHD and BH limitations by calculating IS and LVEF.

Background Simultaneous-Multi-Slice (SMS) perfusion imaging has the potential to acquire multiple slices, increasing myocardial coverage without sacrificing in-plane spatial resolution. To maximise signal-to-noise ratio (SNR), SMS can be combined with a balanced steady state free precession (bSSFP) readout. Furthermore, application of gradient-controlled local Larmor adjustment (GC-LOLA) can ensure robustness against off-resonance artifacts and SNR loss can be mitigated by applying iterative reconstruction with spatial and temporal regularisation. The objective of this study was to compare cardiovascular magnetic resonance (CMR) myocardial perfusion imaging using SMS bSSFP imaging with GC-LOLA and iterative reconstruction to 3 slice bSSFP. Methods Two contrast-enhanced rest perfusion sequences were acquired in random order in 8 patients: 6-slice SMS bSSFP and 3 slice bSSFP. All images were reconstructed with TGRAPPA. SMS images were also reconstructed using a non-linear iterative reconstruction with L1 regularisation in wavelet space (SMS-iter) with 7 different combinations for spatial (λσ) and temporal (λτ) regularisation parameters. Qualitative ratings of overall image quality (0 = poor image quality, 1 = major artifact, 2 = minor artifact, 3 = excellent), perceived SNR (0 = poor SNR, 1 = major noise, 2 = minor noise, 3 = high SNR), frequency of sequence related artifacts and patient related artifacts were undertaken. Quantitative analysis of contrast ratio (CR) and percentage of dark rim artifact (DRA) was performed. Results Among all SMS-iter reconstructions, SMS-iter 6 (λσ 0.001 λτ 0.005) was identified as the optimal reconstruction with the highest overall image quality, least sequence related artifact and higher perceived SNR. SMS-iter 6 had superior overall image quality (2.50 ± 0.53 vs 1.50 ± 0.53, p = 0.005) and perceived SNR (2.25 ± 0.46 vs 0.75 ± 0.46, p = 0.010) compared to 3 slice bSSFP. There were no significant differences in sequence related artifact, CR (3.62 ± 0.39 vs 3.66 ± 0.65, p = 0.88) or percentage of DRA (5.25 ± 6.56 vs 4.25 ± 4.30, p = 0.64) with SMS-iter 6 compared to 3 slice bSSFP. Conclusions SMS bSSFP with GC-LOLA and iterative reconstruction improved image quality compared to a 3 slice bSSFP with doubled spatial coverage and preserved in-plane spatial resolution. Future evaluation in patients with coronary artery disease is warranted. Electronic supplementary material The online version of this article (10.1186/s12968-018-0502-7) contains supplementary material, which is available to authorized users.

Background Conventional 2D inversion recovery (IR) and phase sensitive inversion recovery (PSIR) late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) have been widely incorporated into routine CMR for the assessment of myocardial viability. However, reliable suppression of fat signal, and increased isotropic spatial resolution and volumetric coverage within a clinically feasible scan time remain a challenge. In order to address these challenges, this work proposes a highly efficient respiratory motion-corrected 3D whole-heart water/fat LGE imaging framework. Methods An accelerated IR-prepared 3D dual-echo acquisition and motion-corrected reconstruction framework for whole-heart water/fat LGE imaging was developed. The acquisition sequence includes 2D image navigators (iNAV), which are used to track the respiratory motion of the heart and enable 100% scan efficiency. Non-rigid motion information estimated from the 2D iNAVs and from the data itself is integrated into a high-dimensional patch-based undersampled reconstruction technique (HD-PROST), to produce high-resolution water/fat 3D LGE images. A cohort of 20 patients with known or suspected cardiovascular disease was scanned with the proposed 3D water/fat LGE approach. 3D water LGE images were compared to conventional breath-held 2D LGE images (2-chamber, 4-chamber and stack of short-axis views) in terms of image quality (1: full diagnostic to 4: non-diagnostic) and presence of LGE findings. Results Image quality was considered diagnostic in 18/20 datasets for both 2D and 3D LGE magnitude images, with comparable image quality scores (2D: 2.05 ± 0.72, 3D: 1.88 ± 0.90, p-value = 0.62) and overall agreement in LGE findings. Acquisition time for isotropic high-resolution (1.3mm3) water/fat LGE images was 8.0 ± 1.4 min (3-fold acceleration, 60–88 slices covering the whole heart), while 2D LGE images were acquired in 5.6 ± 2.2 min (12–18 slices, including pauses between breath-holds) albeit with a lower spatial resolution (1.40–1.75 mm in-plane × 8 mm slice thickness). Conclusion A novel framework for motion-corrected whole-heart 3D water/fat LGE imaging has been introduced. The method was validated in patients with known or suspected cardiovascular disease, showing good agreement with conventional breath-held 2D LGE imaging, but offering higher spatial resolution, improved volumetric coverage and good image quality from a free-breathing acquisition with 100% scan efficiency and predictable scan time.

Background Feature tracking (FT) has become an established tool for cardiovascular magnetic resonance (CMR)-based strain analysis. Recently, the compressed sensing (CS) technique has been applied to cine CMR, which has drastically reduced its acquisition time. However, the effects of CS imaging on FT strain analysis need to be carefully studied. This study aimed to investigate the use of CS cine CMR for FT strain analysis compared to conventional cine CMR. Methods Sixty-five patients with different left ventricular (LV) pathologies underwent both retrospective conventional cine CMR and prospective CS cine CMR using a prototype sequence with the comparable temporal and spatial resolution at 3 T. Eight short-axis cine images covering the entire LV were obtained and used for LV volume assessment and FT strain analysis. Prospective CS cine CMR data over 1.5 heartbeats were acquired to capture the complete end-diastolic data between the first and second heartbeats. LV volume assessment and FT strain analysis were performed using a dedicated software (ci42; Circle Cardiovasacular Imaging, Calgary, Canada), and the global circumferential strain (GCS) and GCS rate were calculated from both cine CMR sequences. Results There were no significant differences in the GCS (− 17.1% [− 11.7, − 19.5] vs. − 16.1% [− 11.9, − 19.3; p = 0.508) and GCS rate (− 0.8 [− 0.6, − 1.0] vs. − 0.8 [− 0.7, − 1.0]; p = 0.587) obtained using conventional and CS cine CMR. The GCS obtained using both methods showed excellent agreement (y = 0.99x − 0.24; r = 0.95; p Conclusion CS cine CMR could be used for GCS assessment by CMR-FT as well as conventional cine CMR. This finding further enhances the clinical utility of high-speed CS cine CMR imaging.

BACKGROUND: Cardiac magnetic resonance cine images are conventionally acquired in breath-hold with a segmented balanced steady-state free precession (bSSFP) sequence, which requires a relatively long acquisition time and high patient cooperation. The single-shot compressed sensing (ss CS) cine sequence is a real-time sequence that has reasonable spatial and temporal resolution and can be applied during free breathing. However, the contrast between the myocardium and surrounding soft tissue is relatively reduced, and the epicardial delineation results are not as accurate with the ss CS cine sequence compared with the bSSFP sequence. In this study, we evaluated the use of a 2-shot CS cine technique in quickly acquiring high-quality images and accurately assessing cardiac function in clinical practice. METHODS: The patients enrolled in the study underwent cardiovascular magnetic resonance (CMR) on a 3T scanner from Jul. to Dec. 2018. Cine imaging was performed with 3 different methods: a standard segment cine sequence, a real-time ss CS cine sequence, and a 2-shot CS cine sequence prototype. Quantitative analysis of image quality was performed using a 0-4 scoring system, and also edge sharpness was measured, and cardiac function analysis was performed for all 3 types of cine images. RESULTS: Thirty-eight patients underwent imaging with the three types of cine sequences. The average scan time of the standard cine sequence was 101±20 s, the average scan time of the ss CS cine sequence was 20±4 s, and the average scan time of the 2-shot CS cine sequence was 30±6 s. The standard cine sequence image score was 3.68±0.64 and edge sharpness was (2.47±0.18) mm, the ss CS cine sequence image score was 3.13±0.35 and edge sharpness was (4.69±0.02) mm, and the 2-shot cine sequence image score was 3.54±0.51 and the edge sharpness was (2.51±0.13) mm. In terms of the quantitative study of cardiac function, the differences between the standard cine sequence and the ss CS cine sequence were not statistically significant, except for those of the imaging score and LV mass. There were no significant differences in the cardiac function parameters between the standard cine sequence and the 2-shot cine sequence. There was a strong correlation between the standard cine and ss CS cine sequences and between the standard cine and 2-shot CS cine sequences (P

Background Coronary 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. Methods Fifty 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. Results All 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 Conclusions We 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.

Sparsely sampled cardiac cine accelerated acquisitions show promise for faster evaluation of left-ventricular function. Myocardial strain estimation using image feature tracking methods is also becoming widespread. However, it is not known whether highly accelerated acquisitions also provide reliable feature tracking strain estimates. Twenty patients and twenty healthy volunteers were imaged with conventional 14-beat/slice cine acquisition (STD), 4× accelerated 4-beat/slice acquisition with iterative reconstruction (R4), and a 9.2× accelerated 2-beat/slice real-time acquisition with sparse sampling and iterative reconstruction (R9.2). Radial and circumferential strains were calculated using non-rigid registration in the mid-ventricle short-axis slice and inter-observer errors were evaluated. Consistency was assessed using intra-class correlation coefficients (ICC) and bias with Bland–Altman analysis. Peak circumferential strain magnitude was highly consistent between STD and R4 and R9.2 (ICC = 0.876 and 0.884, respectively). Average bias was −1.7 ± 2.0 %, p

Cardiac MR is considered the gold standard in assessing RV function. The purpose of this study is to evaluate the clinical utility of an investigational iterative reconstruction algorithm in the quantitative assessment of RV function. This technique has the potential to improve the clinical utility of CMR in the evaluation of RV pathologies, particularly in patients with dyspnea, by shortening acquisition times without adversely influencing imaging performance. Segmented cine images were acquired on 9 healthy volunteers and 29 patients without documented RV pathologies using conventional GRAPPA acquisition with factor 2 acceleration (GRAPPA 2), a spatio-temporal TSENSE acquisition with factor 4 acceleration (TSENSE 4), and iteratively reconstructed Sparse SENSE acquisition with factor 4 acceleration (IS-SENSE 4). 14 subjects were re-analyzed and intraclass correlation coefficients (ICC) were calculated and Bland-Altman plots generated to assess agreement. Two independent reviewers qualitatively scored images. Comparison of acquisition techniques was performed using univariate analysis of variance (ANOVA). Differences in RV EF, BSA-indexed ESV (ESVi), BSA-indexed EDV (EDVi), and BSA-indexed SV (SVi) were shown to be statistically insignificant via ANOVA testing. R(2) values for linear regression of TSENSE 4 and IS-SENSE 4 versus GRAPPA 2 were 0.34 and 0.72 for RV-EF, and 0.61 and 0.76 for RV-EDVi. ICC values for intraobserver and interobserver quantification yielded excellent agreement, and Bland-Altman plots assessing agreement were generated as well. Qualitative review yielded small, but statistically significant differences in image quality and noise between TSENSE 4 and IS-SENSE 4. All three techniques were rated nearly artifact free. Segmented imaging acquisitions with IS-SENSE reconstruction and an acceleration factor of 4 accurately and reliably quantitates RV systolic function parameters, while maintaining image quality. TSENSE-4 accelerated acquisitions showed poorer correlation to standard imaging, and inferior interobserver and intraobserver agreement. IS-SENSE has the potential to shorten cine acquisition times by 50 %, improving imaging options in patients with intermittent arrhythmias or difficulties with breath holding.

To evaluate the qualitative and quantitative performance of an accelerated cardiovascular MRI (CMR) protocol that features iterative SENSE reconstruction and spatio-temporal L1-regularization (IS SENSE). Twenty consecutively recruited patients and 9 healthy volunteers were included. 2D steady state free precession cine images including 3-chamber, 4-chamber, and short axis slices were acquired using standard parallel imaging (GRAPPA, acceleration factor = 2), spatio-temporal undersampled TSENSE (acceleration factor = 4), and IS SENSE techniques (acceleration factor = 4). Acquisition times, quantitative cardiac functional parameters, wall motion abnormalities (WMA), and qualitative performance (scale: 1-poor to 5-excellent for overall image quality, noise, and artifact) were compared. Breath-hold times for IS SENSE (3.0 ± 0.6 s) and TSENSE (3.3 ± 0.6) were both reduced relative to GRAPPA (8.4 ± 1.7 s, p 0.001). No difference in quantitative cardiac function was present between the three techniques (p = 0.89 for ejection fraction). GRAPPA and IS SENSE had similar image quality (4.7 ± 0.4 vs. 4.5 ± 0.6, p = 0.09) while, both techniques were superior to TSENSE (quality: 4.1 ± 0.7, p 0.001). GRAPPA WMA agreement with IS SENSE was good (κ 0.60, p 0.001), while agreement with TSENSE was poor (κ 0.40, p 0.001). IS SENSE is a viable clinical CMR acceleration approach to reduce acquisition times while maintaining satisfactory qualitative and quantitative performance.

BACKGROUND Compressed sensing (CS) cine magnetic resonance imaging (MRI) has the advantage of being inherently insensitive to respiratory motion. This study compared the accuracy of free-breathing (FB) CS and breath-hold (BH) standard cine MRI for left ventricular (LV) volume assessment.Methods and Results:Sixty-three patients underwent cine MRI with both techniques. Both types of images were acquired in stacks of 8 short-axis slices (temporal/spatial resolution, 41 ms/1.7×1.7×6 mm3) and compared for ejection fraction, end-diastolic and systolic volumes, stroke volume, and LV mass. Both BH standard and FB CS cine MRI provided acceptable image quality for LV volumetric analysis (score ≥3) in all patients (4.7±0.5 and 3.7±0.5, respectively; P

Background Cardiovascular cine magnetic resonance (CMR) accelerated by compressed sensing (CS) is used to assess left ventricular (LV) function. However, it is difficult for prospective CS cine CMR to capture the complete end-diastolic phase, which can lead to underestimation of the end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), compared to retrospective standard cine CMR. This prospective study aimed to evaluate the diagnostic quality and accuracy of single-breath-hold full cardiac cycle CS cine CMR, acquired over two heart beats, to quantify LV volume in comparison to multi-breath-hold standard cine CMR. Methods Eighty-one participants underwent standard segmented breath-hold cine and CS real-time cine CMR examinations to obtain a stack of eight contiguous short-axis images with same high spatial (1.7 × 1.7 mm2) and temporal resolution (41 ms). Two radiologists independently performed qualitative analysis of image quality (score, 1 [i.e., “nondiagnostic”] to 5 [i.e., “excellent”]) and quantitative analysis of the LV volume measurements. Results The total examination time was 113 ± 7 s for standard cine CMR and 24 ± 4 s for CS cine CMR (p

Background Cardiac MR (CMR) has emerged as the gold standard for assessing right-ventricular (RV) size and function with cine acquisitions. However, dyspnea often accompanies RV dysfunction, limiting patient ability to breathhold and consequently image quality at CMR. The application of a novel iterative reconstruction technique to segmented CMR cine acquisitions may enable higher acceleration factors, shortening image acquisitions, while maintaining image quality for RV assessment. The purpose of this study is to evaluate the clinical utility of a prototype iterative reconstruction algorithm utilizing spatio-temporal L1-regularization (iteratively reconstructed Sparse-SENSE) in the quantitative assessment of RV systolic function.

Background CE-MRA following the injection of a gadolinium-based contrast agent (GBCA) bolus is widely used in clinical assessment of vascular dynamics and tissue perfusion (1,2). Although keyhole techniques with an increased number of central k-space updates further improved contrast kinetics information, spatial resolution remains limited. Alternatively applied view sharing approaches also result in prolonged temporal footprints with possible temporal blurring or reconstruction artifacts. Sparse, incoherent sampling approaches and iterative reconstruction techniques have proven successful particularly in dynamic MR imaging (3). We sought to evaluate the impact of iterative reconstruction techniques on dynamic contrast enhanced MRA of the thoracic aorta.

Delayed contrast-enhanced cardiovascular magnetic resonance (DE-CMR) allows assessment of reversibility of myocardial dysfunction. Comparative data to other modalities is scarce. Purpose of this study was to compare DE-CMR and (201)Thallium single photon emission computed tomography (SPECT) for prediction of reversible left ventricular (LV) dysfunction in patients with chronic ischaemic heart disease. Fifty-four patients with LV dysfunction (mean ejection fraction (EF) 35 ± 8%) scheduled to undergo myocardial revascularization underwent DE-CMR and SPECT. Cine CMR was performed at baseline and at 8 months follow-up for assessment of regional and global myocardial function. Myocardial viability was determined by the segmental extent of delayed enhancement for DE-CMR, and by quantitative analysis of tracer uptake for SPECT, and was correlated to functional recovery after revascularization. After revascularization, 172 (49%) of 350 dysfunctional segments improved at follow-up cine CMR. Sensitivity and specificity for the prediction of functional recovery was 92 and 88%, respectively, for DE-CMR as compared to 86% (P = 0.4) and 56% (P = 0.001) for SPECT. Global LV function showed an increase of EF > 5% in 22 (41%) patients. The DE-CMR derived viability ratio (dysfunctional but viable myocardium) of 0.46 (sensitivity 91%, specificity 91%) was identified as predictor of increase in EF > 5% (P = 0.02), whereas the corresponding SPECT parameters were not predictive. DE-CMR compares favorably to SPECT for the prediction of regional and global improvement in LV function in the setting of chronic myocardial ischemia.

Methods All patients were submitted to a conventional cardiac magnetic resonance study (Magnetom Aera, Siemens AG Healthcare, Germany) that included shortand long-axis steady-state free-precession (SSFP) segmented cine measurements (spatial resol.: 1.5x1.5 mm; slice thickness: 7 mm; temporal resol.: 40 ms; 7 heart beats (HB)/slice), modified Look-Locker inversion recovery post-contrast T1 mapping (spatial resol.: 1.6x1.6 mm; slice thickness: 8 mm; 17 HB/slice), and segmented spoiled gradient-echo late gadolinium enhancement (LGE) images (spatial resol.: 1.6x1.6 mm; slice thickness: 8 mm; 8-10 HB/slice). Followed by multi-TI real-time cine performed in the same cardiac planes (spatial resol.: 2.1x2.1 mm; slice thickness: 8 mm; temporal resol.: 45 ms; 4 HB/slice). The multi-TI cine prototype has been described in detail elsewhere, but briefly it consists of an inversion recovery highly accelerated SSFP 2D real-time cine sequence, featuring sparse sampling and k-t regularization. Using an offline reconstruction algorithm based on a registration and motion-propagation strategy, a full-length cine can be reconstructed for each acquired TI (fig. 1) and also a pseudo-T1 map cine. Results A total of 12 consecutive patients (61% male, 50±19 yrs) were included. All sequences were successfully performed and reconstructed, rendering good-quality images on subjective analysis. In all patients, a multi-TI cine, with ideal myocardial nulling, could be produced for simultaneous cardiac function and LGE analysis. Figure 2 illustrates a case of myocardial infarction with evident apical fibrosis on LGE and post-contrast T1 map, associated with akinesia of the involved segments on standard cines. On multi-TI cine, both abnormalities could be fully appreciated. In a subject with myocarditis, subtle mesocardial LGE without segmental contractility dysfunction was also adequately depicted on multi-TI cines (fig. 1). Conventional cine and LGE together required more time and breath-holds than multi-TI cines (745±210 seconds and 13±1 BH vs. 357±39 seconds and 3±0 BH respectively).

Methods A highly accelerated prototype cine sequence with sparse sampling and Iterative Reconstruction (sCINE-IR) was used in phantoms and patients to acquire 5 cine slices (2 long axis, LAX and 3 short axis, SAX) through the LA during a single breathhold yielding a spatial/temporal resolution of 1.5mm/30ms (1.5T Aera, Siemens AG, Germany). The LA volumes were reconstructed from these 5 slices using a non-model based method (Bermano A, ACM trans Graph 2011). As a reference in patients, a self-navigated high-resolution whole-heart 3D dataset (3D-HR) was acquired during mid-diastole, from which the LA volume was segmented. Phantom study. Five LA phantoms made of solanum tuberosum L of known volume (water displacement method) and of different shapes were imaged with both 3D-HR and CS in various slice orientations and the calculated volumes were compared. Patients study. Three patients were scanned with both 3D-HR and sCINE-IR. The volumes obtained with 3D-HR and with sCINE-IR during the corresponding mid-diastolic frame were compared using Bland-Altman method and linear regression.

Background CMR is generally accepted as the gold standard for left ventricular (LV) volumes and function assessment. The conventional CMR approach involves several breathholds to cover the entire heart with short-axis acquisitions. Recently, compressed sensing (CS) techniques emerged as a means to considerably accelerate data acquisition. CS principally relies on: 1) transform sparsity, 2) incoherence of undersampling artifacts, and 3) nonlinear reconstruction. PURPOSE: To compare a novel CS-based single breath-hold multi-slice cine technique with the standard multi-breath-hold technique for the assessment of LV volumes and function.

Background Recently developed compressed sensing (CS) SSFP sequences significantly reduce data acquisition time thereby reducing patient breath-hold and scan time relative to standard techniques. The variability of ventricular functional (VF) analysis of CS data is not known so this study investigated the inter-observer variation of left ventricular (LV) mass and volume measurements compared to standard SSFP acquisitions.

Background In patients with breath-holding difficulties or arrhythmia, real-time CINE-MRI is preferred over segmented acquisitions in one breath-hold. However, common real-time sequences require a deteriorating trade-off between spatial and temporal resolution. In the current work, highly accelerated real-time CINE-MRI which features compressed sensing with k t regularization [1] was evaluated against segmented and real-time imaging with TSENSE in healthy volunteers as a potential alternative providing both high spatial and temporal resolution in real time.

Background Compressed sensing promises to achieve a significant acceleration of the data acquisition in the case of realtime CINE-MRI. The major challenge is to achieve both high spatial and temporal resolution. In the current work, an alternative solution to k-t SPARSE SENSE is proposed which exploits spatio-temporal correlations beneficially.

Background A new fast and robust technique combing CINE imaging with a retrospectively adjustable delayed-enhancement (DE) contrast in a short breath-hold of 4 seconds was recently introduced [1]. As a benefit of this technique, DE images can be reconstructed as a CINE series for any TI contrast, which in turn could be beneficial in the evaluation of CMR images and allow for improved diagnostic accuracy. In this work, we performed an initial clinical evaluation of the technique.

Background MR stress perfusion is a non-invasive, reliable and safe test for ischemic heart disease [1]. Recent publications reported sensitivity and specificity of 89% and 80% respectively [2]. Image quality improvements seem to be essential for improving the predictive value of the method. This leads to the dilemma of finding a compromise between high spatial resolution and sufficient SNR. Lately iterative reconstruction demonstrated great promise in improving SNR [3]. The aim of the current study was to compare cardiac perfusion in 24 patients reconstructed with product and a novel prototype iterative reconstruction. Methods 24 patients (mean age 62 ±15) were examined on a 1.5T clinical MR scanner (MAGNETOM Aera, Siemens AG, Erlangen, Germany) using a saturation prepared TFL product sequence with the following parameters: TR/TE=331/1.4ms ; Flip angle = 12°; BW = 668Hz/Px; Voxel size=0.8×0.8×10.0 mm (inplane interpolated); FOV=290mm2; Matrix = 170x192; Slice thickness=10mm; Acceleration=2; Inversion time= 180ms; Phase oversampling=60%; Motion correction. Pharmacological stress was applied using Adenosine (Adenoscan, Sanofi-Synthelabo). Gadolinium-based contrast agent (Magnevist, Bayer Schering Pharma) was

Predicting therapeutic benefit from percutaneous transluminal renal angioplasty (PTRA) in patients with renal artery stenosis (RAS) remains difficult. This study investigates whether magnetic resonance (MR)-based renal artery flow measurements relative to renal parenchymal volume can predict clinical outcome following PTRA.The data on 23 patients (13 men, 10 women; age range 47-82 years, mean age 64 years) were analyzed. The indication for treatment was hypertension (n = 18) or renal insufficiency (n = 5). Thirty-four cases of RAS were identified: bilateral disease was manifest in 11 and unilateral disease in 12 patients. The MR imaging protocol included a breath-hold, cardiac-gated cine phase-contrast sequence for renal flow measurement and a fast multiplanar spoiled gradient-echo sequence for renal volume measurement. MR measurements were performed on the day prior to and the day following PTRA. Clinical success was defined as (a) a reduction in diastolic blood pressure15% or (b) a reduction in serum creatinine20%. Kidneys were categorized as normal volume or low volume. A renal flow index (RFI) was calculated by dividing the renal flow (ml/min) by the renal volume (cm3).Clinical success was observed in patients. Twelve patients did not benefit from angioplasty. Normal kidney volume was seen in 10 of 11 responders and in 8 of 12 nonresponders, resulting in a sensitivity of 91%, specificity of 33%, a positive predictive value (PPV) of 56% and a negative predictive value (NPV) of 80%. A RFI below a threshold of 1.5 ml/min/cm3 predicted successful outcome with 100% sensitivity, 33% specificity, 58% PPV, and 100% NPV. The combination of normal renal volume and a RFI below 1.5 ml/min/cm3 identified PTRA responders with a sensitivity of 91%, a specificity of 67%, a PPV of 71%, and a NPV of 89%. PTRA resulted in a greater increase in renal flow in responders compared with nonresponders (p0.001).A combination of cine phase-contrast MR renal flow and parenchymal volume measurements enables identification of patients benefiting from PTRA with a high sensitivity and NPV, but only moderate specificity and PPV.

Background While SSFP CMR is the gold standard for assessing left ventricular (LV) function, it requires a regular cardiac rhythm and frequent breath-holds and not all patients with cardiovascular disease are able to achieve this. It is known that Compressed Sensing (CS) greatly reduces data acquisition time however its accuracy for LV volume and mass is currently unknown. This study compares ventricular function measurements by CS to those obtained from standard SSFP cines.

Background The use of gated CMR can be limited by motion artifacts secondary to cardiac and respiratory motion. Imaging is especially challenging in patients with arrhythmias or those who cannot perform adequate breath-holds. Realtime CMR is a non-gated technique that has been successfully applied in scenarios where standard segmented acquisitions break down. In this study, we sought to accelerate real-time acquisition by using sparse sampling with an iterative SENSE reconstruction.

Background Changes in myocardial strain have been shown to precede onset of systolic dysfunction in patients with cardiomyopathy. Traditionally performed with echocardiography, acoustic windows can limit strain evaluation. Preliminary work has shown good agreement between myocardial strain derived from deformation field analysis at balanced steady-state free-precession (bSSFP) cine MRI and speckle tracking echocardiography. The application of a novel prototype iterative SENSE reconstruction with L1 regularization (IRSENSE) to highly accelerated segmented bSSFP cine acquisitions can maintain or improve the effective temporal resolution with a shorter breath-hold. The purpose of this study is to evaluate left- and right-ventricular stain analysis from bSSFP cine acquisitions using conventional GRAPPA and highly accelerated T-PAT with IR-SENSE. We hypothesize that myocardial strain parameters derived from accelerated T-PAT cine acquisitions with IR-SENSE are similar to those obtained using conventional segmented bSSFP with comparable effective temporal resolutions.

Background Segmented cine imaging with a steady-state free precession sequence (CINE-SSFP) is currently the gold standard technique for measuring ventricular volumes and mass. It requires multiple breath-holds to cover the entire ventricles, thus being prone to misalignment of consecutive slices, time consuming and dependent on breath-hold (BH) capability. Real-time cine avoids those limitations, however poor spatial and temporal resolution of conventional sequences have prevented its routine application. We sought to examine if a newly developed real-time sequence featuring compressed sensing and iterative reconstruction (CINE-RT), which is an investigational prototype, would yield similar results when compared with conventional CINE-SSFP in a group of healthy volunteers. Methods

To describe the three-dimensional magnetic resonance angiography (3D MRA) imaging appearance of the pulmonary arteries following administration of a superparamagnetic iron oxide blood pool agent to human volunteers, and to demonstrate in an animal model (pigs) how this technique can be used to detect pulmonary parenchymal hemorrhage.Two volunteers were examined following the intravenous administration of a superparamagnetic iron oxide blood pool agent (NC100150 Injection, Nycomed Amersham Imaging, Wayne, PA, USA). T1-weighted 3D gradient recalled echo (GRE) image sets (TR/TE 5.1/1.4 msec, flip angle 30 degrees ) were acquired breath-held over 24 sec. To assess the detectability of pulmonary bleeding with intravascular MR contrast, pulmonary parenchymal injuries were created in two animals under general anesthesia, and fast T1-weighted 3D GRE image sets collected before and after the injury.Administration of the intravascular contrast in the two volunteers resulted in selective enhancement of the pulmonary vasculature permitting complete visualization and excellent delineation of central, segmental, and subsegmental arteries. Following iatrogenic injury in the two animals, pulmonary hemorrhage was readily detected on the 3D image sets.The data presented illustrate that ultrafast 3D GRE MR imaging in conjunction with an intravenously administered intravascular blood pool agent can be used to perform high-quality pulmonary MRA as well as to detect pulmonary hemorrhage.

Background Strong evidence in favour of an ischaemia-guided approach to coronary revascularisation for PCI has led to a huge increase in demand for ischaemia imaging. In our General Hospital setting we have seen a 300% increase in demand for stress MRI over 3 years to more than 800 examinations per year. We therefore sought to optimise patient throughput by process mapping and by the introduction of new semiautomated scanning software. The aim of the study was to assess the impact of these changes on MRI study time.

ObjectivesThe purpose of this study was to compare a novel compressed sensing (CS)–based single–breath-hold multislice magnetic resonance cine technique with the standard multi–breath-hold technique for the assessment of left ventricular (LV) volumes and function.BackgroundCardiac magnetic resonance is generally accepted as the gold standard for LV volume and function assessment. LV function is 1 of the most important cardiac parameters for diagnosis and the monitoring of treatment effects. Recently, CS techniques have emerged as a means to accelerate data acquisition.MethodsThe prototype CS cine sequence acquires 3 long-axis and 4 short-axis cine loops in 1 single breath-hold (temporal/spatial resolution: 30 ms/1.5 × 1.5 mm2; acceleration factor 11.0) to measure left ventricular ejection fraction (LVEFCS) as well as LV volumes and LV mass using LV model–based 4D software. For comparison, a conventional stack of multi–breath-hold cine images was acquired (temporal/spatial resolution 40 ms/1.2 × 1.6 mm2). As a reference for the left ventricular stroke volume (LVSV), aortic flow was measured by phase-contrast acquisition.ResultsIn 94% of the 33 participants (12 volunteers: mean age 33 ± 7 years; 21 patients: mean age 63 ± 13 years with different LV pathologies), the image quality of the CS acquisitions was excellent. LVEFCS and LVEFstandard were similar (48.5 ± 15.9% vs. 49.8 ± 15.8%; p = 0.11; r = 0.96; slope 0.97; p < 0.00001). Agreement of LVSVCS with aortic flow was superior to that of LVSVstandard (overestimation vs. aortic flow: 5.6 ± 6.5 ml vs. 16.2 ± 11.7 ml, respectively; p = 0.012) with less variability (r = 0.91; p < 0.00001 for the CS technique vs. r = 0.71; p < 0.01 for the standard technique). The intraobserver and interobserver agreement for all CS parameters was good (slopes 0.93 to 1.06; r = 0.90 to 0.99).ConclusionsThe results demonstrated the feasibility of applying the CS strategy to evaluate LV function and volumes with high accuracy in patients. The single–breath-hold CS strategy has the potential to replace the multi–breath-hold standard cardiac magnetic resonance technique.

Background MR imaging of the heart typically involves the acquisition of standard views aligned with the heart axes. Timeefficient and reproducible planning requires expertise in heart geometry and anatomy. In this study, we evaluate the ability of fully automatic heart view localization software to detect the long-axis views of the heart and compare the results both visually and geometrically with manual localization. Methods

Methods IRB approval was obtained. Twenty patients (age: 54.8 ± 14 years, M:F = 15:5) undergoing non-emergent CMR assessment for myocardial pathology were consecutively recruited. Nine healthy volunteers (age: 44.3 ± 14 years, M:F = 6:3) were also imaged. CMR was performed at 1.5T (MAGNETOM Aera, Siemens Healthcare, Erlangen, Germany). The examination included acquisition of standard segmented SSFP (iPAT2) (GRAPPA accel factor 2, TR 40 msec, 2.1 × 2.1 × 10 mm) cine and two accelerated segmented SSFP acquisitions (TPAT accel factor 4, TR 37.7 msec, 2.1 × 2.1 × 6 mm), one with an investigational prototype inline iterative k-t-sparse SENSE reconstruction with L1 regularization along one spatial and temporal dimension (TPAT4i) (1)and the other with conventional SENSE reconstruction (TPAT4). Each technique was used to acquire a three(3Ch), four-chamber (4Ch), and short axis (SA) series in identical slice positions (Figure 1), with SA coverage of the entire left ventricle (LV) with 10 mm interslice gaps. Individual slice scan times were recorded. Quantitative LV functional analysis was performed. A reviewer blinded to acquisition type scored images for overall image quality, noise, and artifacts using a 5-point Likert scale. Continuous variables were compared between groups using a paired t-test, and ordinal variables were compared using a Wilcoxon signed-rank test.

Background Magnetic Resonance (MR) cardiac cine is generally accepted as the gold standard for left ventricular (LV) volume assessment. Recently, Real-Time (RT) cine with sparse sampling technique and iterative reconstruction has been applied to accelerate cine MR. However, in prospective electrocardiogram (ECG) triggered RT cine MR, it may be difficult to capture the true end diastole phase because of the finite time needed to detect the next ECG trigger, which may lead to underestimation of end diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF) when compared with retrospective ECG gated standard cine MR. In this study we propose an alternative approach to overcome this limitation, by acquiring sparse RT cine MR data over two heart beats, to capture the complete end diastole between the first and second heart beats. The purpose of this study was to evaluate the diagnostic quality and accuracy of RT-based single-breath-hold cine MR for the quantification of LV function compared with standard multi-breath-hold cine MR.

Background Despite being the gold standard for left ventricular function evaluation, traditional SSFP sequences still require multiple breath-holds and a relatively long scan time. This extends total duration of the exam, especially in children or adults with impaired cardiopulmonary capacity. We sought to compare a technique employing a prototype sparse sampling with iterative reconstruction (SSIR) for rapid evaluation of the left ventricle (Liu J et al. ISMRM; 2012) in a single breath-hold and freebreathing (FB) compared to traditional SSFP sequences and temporal parallel imaging methods.

regularization of the SENSE type dataset. Datasets were analysed by two experienced readers (>10 years CMR analysis), with papillary muscles and trabeculae included in the blood pool. Comparison of TrueFISP and CV_sparse was assessed using paired t-test and Pearson’s correlation, and inter-observery reproducibility by Bland-Altman Results 26 clinical patients had both TrueFISP and CV_sparse imaging successfully performed (figure1A,B), mean LVEF 49% (range 16-65%). Strong positive correlation was present for end-diastolic volumes (r=0.98, P< 0.0001), end-systolic volume (r=0.99, P< 0.0001), LVmass (r=0.97, P< 0.0001) and LVEF (r=0.97, P< 0.0001), with no difference between the groups (P=0.95 NS), figure1C. Reproducibility was excellent with bias 0.3%, limits-of-agreement -3.7 to 4.3% (figure1D). Acquisition time for the LVSAX series was significantly shorter for CV_sparse compared to TrueFISP (p

Background A typical CMR exam consists of a limited number of 2D scans that provide standard views of the heart. Diagnosis is limited to these select views. For the acquisition, multiple breath-holds are required a challenge for many patients. As an improvement, we have investigated a free-breathing (FB) 2D acquisition protocol in conjunction with a novel reconstruction approach. The method provides 3D+time cine data with full heart coverage while simplifying the acquisition.

Background In uncooperative patients or in presence of arrhythmia, real-time free-breathing cine MR approaches may offer an alternative to well-established segmented data acquisition strategies [1,2]. Segmented acquisition strategies collect data throughout a number of heartbeats and typically a fixed number of cardiac phases are reconstructed for each slice representing an average RR interval. In real-time cine imaging, the number of reconstructed phases may be different for each slice due to heart rate variations. However, it is desirable to reconstruct a predefined number of cardiac phases per slice to facilitate functional analysis and processing. In this work, we present an image reconstruction approach that retrospectively interpolates real-time cine images to calculate a predefined number of cardiac phases per heartbeat and slice. Ejection fraction is compared between segmented cine images and interpolated realtime cine images in healthy volunteers. Methods

BackgroundLocalization of the heart is typically performed using amulti-step approach involving the acquisition of double-oblique localizer images. Based on the localizers thestandard heart views are planned. This approach isoperator-dependent and time consuming.ObjectiveTo demonstrate feasibility of a fully automatic and fastapproach to heart localization and slice prescriptionfrom a highly-accelerated, single breath-hold 3D acquisi-tion through a machine learning method.MethodsA 3D full-chest MR scan is obtained through parallelimaging within a single breath-hold. A single volume isacquired at mid-diastole using an ECG gated segmentedacquisition with T2-prepared SSFP readout with chemi-cal shift fat suppression. Typical protocol parametersare: 400x400x220 mm