Journal of Cardiovascular Magnetic Resonance最新文献

Background: Although quantitative myocardial T1 and T2 mappings are clinically used to evaluate myocardial diseases, their application needs a minimum of six breath-holds to cover three short-axis slices. The purpose of this work is to simultaneously quantify multislice myocardial T1 and T2 across three short-axis slices in one breath-hold by combining simultaneous multislice (SMS) with multimapping.

Methods: An SMS-Multimapping sequence with multiband radiofrequency (RF) excitations and Cartesian fast low-angle shot readouts was developed for data acquisition. When 3 slices are simultaneously acquired, the acceleration rate is around 12-fold, causing a highly ill-conditioned reconstruction problem. To mitigate image artifacts and noise caused by the ill-conditioning, a reconstruction algorithm based on locally low-rank and sparsity (LLRS) constraints was developed. Validation was performed in phantoms and in vivo imaging, with 20 healthy subjects and 4 patients, regarding regional mean, precision, and scan-rescan reproducibility.

Results: The phantom imaging shows that SMS-Multimapping with locally low-rank (LLRS) accurately reconstructed multislice T1 and T2 maps despite a six-fold acceleration of scan time. Healthy subject imaging shows that the proposed LLRS algorithm substantially improved image quality relative to split slice-generalized autocalibrating partially parallel acquisition. Compared with modified look-locker inversion recovery (MOLLI), SMS-Multimapping exhibited higher T1 mean (1118 ± 43 ms vs 1190 ± 49 ms, P < 0.01), lower precision (67 ± 17 ms vs 90 ± 17 ms, P < 0.01), and acceptable scan-rescan reproducibility measured by 2 scans 10-min apart (bias = 1.4 ms for MOLLI and 9.0 ms for SMS-Multimapping). Compared with balanced steady-state free precession (bSSFP) T2 mapping, SMS-Multimapping exhibited similar T2 mean (43.5 ± 3.3 ms vs 43.0 ± 3.5 ms, P = 0.64), similar precision (4.9 ± 2.1 ms vs 5.1 ± 1.0 ms, P = 0.93), and acceptable scan-rescan reproducibility (bias = 0.13 ms for bSSFP T2 mapping and 0.55 ms for SMS-Multimapping). In patients, SMS-Multimapping clearly showed the abnormality in a similar fashion as the reference methods despite using only one breath-hold.

Conclusion: SMS-Multimapping with the proposed LLRS reconstruction can measure multislice T1 and T2 maps in one breath-hold with good accuracy, reasonable precision, and acceptable reproducibility, achieving a six-fold reduction of scan time and an improvement of patient comfort.

Background: Patients with syndromic heritable thoracic aortic diseases (sHTAD) who underwent prophylactic aortic root replacement are at high risk of distal aortic events, but the underlying mechanisms remain unclear. This prospective, longitudinal study evaluates the impact of valve-sparing aortic root replacement (VSARR) on aortic fluid dynamics and biomechanics in these patients.

Methods: Sixteen patients with Marfan or Loeys-Dietz syndrome underwent two time-resolved three-dimensional phase-contrast cardiovascular magnetic resonance (4D flow CMR) studies before (sHTAD-preSx) and after VSARR (sHTAD-postSx). Two matched cohorts of 40 healthy volunteers (HV) and 16 sHTAD patients without indication for aortic root replacement (sHTAD-NSx) with available 4D flow CMR were included for comparison. In-plane rotational flow (IRF), systolic flow reversal ratio (SFRR), wall shear stress (WSS), pulse wave velocity (PWV), and aortic strain were analyzed in the ascending (AscAo) and descending aorta (DescAo).

Results: All patients with sHTAD presented altered hemodynamics and increased stiffness (p < 0.05) compared to HV, both in the AscAo (median PWV 7.4 in sHTAD-NSx; 6.8 in sHTAD-preSx; 4.9 m/s in HV) and DescAo (median PWV 9.1 in sHTAD-NSx; 8.1 in sHTAD-preSx; 6.3 m/s in HV). Patients awaiting VSARR had markedly reduced in-plane (median IRF -2.2 vs 10.4 cm²/s in HV, p = 0.001), but increased through-plane flow rotation (median SFRR 7.8 vs 3.8% in HV, p = 0.002), and decreased WSS (0.36 vs 0.47 N/m² in HV, p = 0.004) in the proximal DescAo. After VSARR, proximal DescAo IRF (p = 0.010) and circumferential WSS increased (p = 0.011), no longer differing from HV, but SFRR, axial WSS and stiffness remained altered. Patients in which aortic tortuosity was reduced after surgery showed greater post-surgical increase in IRF compared to those in which tortuosity increased (median IRF increase 18.1 vs 3.3 cm²/s, p = 0.047). Most AscAo flow alterations were restored to physiological values after VSARR.

Conclusion: In patients with sHTAD, VSARR partially restores downstream fluid dynamics to physiological levels. However, some flow disturbances and increased stiffness persist in the proximal DescAo. Further longitudinal studies are needed to evaluate whether persistent alterations contribute to post-surgical risk.

Background: Cardiovascular magnetic resonance (CMR) chemical shift encoding (CSE) enables myocardial fat imaging. We sought to develop a deep learning network (fast chemical shift encoding [FastCSE]) to accelerate CSE.

Methods: FastCSE was built on a super-resolution generative adversarial network extended to enhance complex-valued image sharpness. FastCSE enhances each echo image independently before water-fat separation. FastCSE was trained with retrospectively identified cines from 1519 patients (56 ± 16 years; 866 men) referred for clinical 3T CMR. In a prospective study of 16 participants (58 ± 19 years; 7 females) and 5 healthy individuals (32 ± 17 years; 5 females), dual-echo CSE images were collected with 1.5 × 1.5 mm², 2.5 × 1.5 mm², and 3.8 × 1.9 mm² resolution using generalized autocalibrating partially parallel acquisition (GRAPPA). FastCSE was applied to images collected with resolution of 2.5 × 1.5 mm² and 3.8 × 1.9 mm² to restore sharpness. Fat images obtained from two-point Dixon reconstruction were evaluated using a quantitative blur metric and analyzed with a five-way analysis of variance.

Results: FastCSE successfully reconstructed CSE images inline. FastCSE acquisition, with a resolution of 2.5 × 1.5 mm² and 3.8 × 1.9 mm², reduced the number of breath-holds without impacting visualization of fat by approximately 1.5-fold and 3-fold compared to GRAPPA acquisition with a resolution of 1.5 × 1.5 mm², from 3.0 ± 0.8 breath-holds to 2.0 ± 0.2 and 1.1 ± 0.4 breath-holds, respectively. FastCSE improved image sharpness and removed ringing artifacts in GRAPPA fat images acquired with a resolution of 2.5 × 1.5 mm² (0.32 ± 0.03 vs 0.35 ± 0.04, P < 0.001) and 3.8 × 1.9 mm² (0.32 ± 0.03 vs 0.43 ± 0.06, P < 0.001). Blurring in FastCSE images was similar to blurring in images with 1.5 × 1.5 mm² resolution (0.32 ± 0.03 vs 0.31 ± 0.03, P = 0.57; 0.32 ± 0.03 vs 0.31 ± 0.03, P = 0.66).

Conclusion: We showed that a deep learning-accelerated CSE technique based on complex-valued resolution enhancement can reduce the number of breath-holds in CSE imaging without impacting the visualization of fat. FastCSE showed similar image sharpness compared to a standardized parallel imaging method.

Background: Disordered lymphatic drainage is common in congenital heart diseases (CHD), but thoracic duct (TD) drainage patterns in heterotaxy have not been described in detail. This study sought to describe terminal TD sidedness in heterotaxy and its associations with other anatomic variables.

Methods: This was a retrospective, single-center study of patients with heterotaxy who underwent cardiovascular magnetic resonance imaging at a single center between July 1, 2019 and May 15, 2023. Patients with (1) asplenia (right isomerism), (2) polysplenia (left isomerism) and (3) pulmonary/abdominal situs inversus (PASI) plus CHD were included. Terminal TD sidedness was described as left-sided, right-sided, or bilateral.

Results: Of 115 eligible patients, the terminal TD was visualized in 56 (49 %). The terminal TD was left-sided in 25 patients, right-sided in 29, and bilateral in two. On univariate analysis, terminal TD sidedness was associated with atrial situs (p = 0.006), abdominal situs (p = 0.042), type of heterotaxy (p = 0.036), the presence of pulmonary obstruction (p = 0.041), superior vena cava sidedness (p = 0.005), and arch sidedness (p < 0.001). On multivariable analysis, only superior vena cava and aortic arch sidedness were independently associated with terminal TD sidedness.

Conclusions: Terminal TD sidedness is highly variable in patients with heterotaxy. Superior vena cava and arch sidedness are independently associated with terminal TD sidedness. Type of heterotaxy was not independently associated with terminal TD sidedness. This data improves the understanding of anatomic variation in patients with heterotaxy and may be useful for planning for lymphatic interventions.

Background: Cardiovascular magnetic resonance (CMR) is increasingly utilized to evaluate expanding cardiovascular conditions. The Society for Cardiovascular Magnetic Resonance (SCMR) Registry is a central repository for real-world clinical data to support cardiovascular research, including those relating to outcomes, quality improvement, and machine learning. The SCMR Registry is built on a regulatory-compliant, cloud-based infrastructure that houses searchable content and Digital Imaging and Communications in Medicine images. The goal of this study is to summarize the status of the SCMR Registry at 150,000 exams.

Methods: The processes for data security, data submission, and research access are outlined. We interrogated the Registry and presented a summary of its contents.

Results: Data were compiled from 154,458 CMR scans across 20 United States sites, containing 299,622,066 total images (∼100 terabytes of storage). Across reported values, the human subjects had an average age of 58 years (range 1 month to >90 years old), were 44% (63,070/145,275) female, 72% (69,766/98,008) Caucasian, and had a mortality rate of 8% (9,962/132,979). The most common indication was cardiomyopathy (35,369/131,581, 27%), and most frequently used current procedural terminology code was 75561 (57,195/162,901, 35%). Macrocyclic gadolinium-based contrast agents represented 89% (83,089/93,884) of contrast utilization after 2015. Short-axis cines were performed in 99% (76,859/77,871) of tagged scans, short-axis late gadolinium enhancement (LGE) in 66% (51,591/77,871), and stress perfusion sequences in 30% (23,241/77,871). Mortality data demonstrated increased mortality in patients with left ventricular ejection fraction <35%, the presence of wall motion abnormalities, stress perfusion defects, and infarct LGE, compared to those without these markers. There were 456,678 patient-years of all-cause mortality follow-up, with a median follow-up time of 3.6 years.

Conclusion: The vision of the SCMR Registry is to promote evidence-based utilization of CMR through a collaborative effort by providing a web mechanism for centers to securely upload de-identified data and images for research, education, and quality control. The Registry quantifies changing practice over time and supports large-scale real-world multicenter observational studies of prognostic utility.

Background: Patients with pulmonary hypertension (PH) secondary to left heart failure (HF) exhibit a complex pathophysiological profile and poor prognosis. Left atrial (LA) function is pivotal in the progression of this disease, yet its predictive significance remains exclusive. This study aimed to explore the predictive capability of LA metrics in this population and compare them with other common predictors.

Methods: In this retrospective study, consecutive patients with PH secondary to HF who underwent cardiac magnetic resonance (CMR) imaging between December 2010 and December 2021 were enrolled. The composite endpoint was defined as all-cause death, heart-lung transplantation, or left ventricular assist device implantation. Survival analyses were performed using Kaplan-Meier curves and Cox regression analyses.

Results: A total of 174 patients with PH secondary to HF, with a mean age of 53.2 ± 14.9 years, including 90 men, were included in the final analysis. During a median follow-up of 31.9 months, 33.3% (58/174) of the patients with PH reached the endpoints. There was a fair correlation between active left atrial ejection fraction (LAEF) and pulmonary artery wedge pressure (r = -0.397, p = 0.044). Active LAEF had a strong correlation with oxygen consumption at anaerobic threshold (r = 0.769, p < 0.001) and peak oxygen consumption (r = 0.754, p < 0.001). Active LAEF demonstrated comparable prognostic performance to other variables measured by echocardiography or CMR. After adjusting for clinical variables and left ventricular ejection fraction, active LAEF was still an independent predictor for adverse events (C-statistic: 0.784). Subgroup analysis among HF patients with preserved ejection fraction demonstrated that those with active LAEF ≤8.6% had a 7.05-fold higher risk of experiencing the composite endpoint compared to those with active LAEF >8.6%.

Conclusion: Although active LAEF does not demonstrate statistical improvement in outcome discrimination compared to established metrics, it may still merit consideration for assessing disease severity and prognosis in patients with PH secondary to HF. The integration of active LAEF and HF subtypes may stratify individuals at different levels of risk.

Background: Systemic right ventricular (sRV) physiology occurs in patients with congenitally corrected transposition of the great arteries (ccTGA) and D-TGA post atrial switch repair, and the natural history is of progressive sRV dysfunction. No study has assessed longitudinal changes in sRV remodeling by serial cardiovascular magnetic resonance (CMR).

Methods: Patients evaluated at two adult congenital heart disease centers and who underwent ≥2 CMR exams were studied. Indexed sRV end-diastolic volume (sRVEDVi), end-systolic volume (sRVESVi), and ejection fraction (sRVEF) were determined by a core laboratory. Concurrent echocardiograms were assessed for degree of systemic tricuspid regurgitation (sTR). Tricuspid valve events were defined as ≥moderate sTR, or interval tricuspid valve replacement (TVR). Generally, the earliest and most recent studies were compared. A subset of patients were followed with ≥moderate sTR, and then subsequently underwent interval TVR. For these patients, two study time intervals were defined to analyze the impact of each event independently.

Results: Sixty-seven patients were studied (33 ± 11 years, 48% [32/67] male, 33% [22/67] ccTGA), with 72 total time intervals studied (median interval 9.0 years [interquartile range 4.6-13.3]). There was a small increase in sRVEDVi over time (ΔsRVEDVi 5.5 ± 15.8 mL/m², p < 0.001), but mean change in sRVEF was not significant (ΔsRVEF 0.1 ± 6.9%, p = 0.86); notably, confidence intervals (CI) were wide for both. ccTGA patients had a trend toward greater decrement in sRVEF (ΔsRVEF -1.7 ± 6.8 vs 1.3 ± 6.7%, p = 0.06). For each 25 mL/m² increase in baseline sRVEDVi, there was a 1.8% decrease in sRVEF (95% CI -3.2% to -0.5%, p = 0.01). Patients without significant sTR had lesser deterioration in sRVEF compared to those with ≥moderate sTR or with interval TR intervention (ΔsRVEF 1.8 ± 6.9% vs -2.1 ± 6.6% and -2.6 ± 4.5, p < 0.05). Interval sRV conduction delay was associated with a trend toward greater decrements in sRVEF (ΔsRVEF -3.9 ± 6.3 vs 0.9 ± 6.8%, p = 0.07). Overall, underlying congenital anatomy, baseline sRVEDVi, advanced sTR or interval TVR, and sRV conduction delay explained only 16% of the variability in ΔsRVEF over time.

Conclusion: Longitudinal changes in sRV remodeling were small, with great heterogeneity. Apparent risk factors in our study, namely underlying congenital anatomy, baseline sRVEDVi, TR events, and sRV conduction disease accounted for only 16% of the variability seen in the longitudinal change of sRVEF.

Background: Interstitial fibrosis as quantified by cardiovascular magnetic resonance (CMR) has been demonstrated in arrhythmic mitral valve prolapse (AMVP), a condition with known female predominance. Prior studies of interstitial fibrosis in AMVP have only included cases with significant mitral regurgitation (MR) or mitral annular disjunction (MAD), limiting our understanding of alternative arrhythmic mechanisms in mitral valve prolapse (MVP). We sought to evaluate the association between interstitial fibrosis and AMVP, regardless of MAD and without severe MR, while also investigating the contribution of sex to this association.

Methods: We performed research-based contrast CMR in consecutive individuals with MVP between 2019 and 2022. Extracellular volume fraction (ECV%), a surrogate marker for interstitial fibrosis, was quantified using T₁ mapping in the basal and mid-left ventricular slices. Replacement fibrosis was assessed using late gadolinium enhancement (LGE). AMVP was defined as MVP with frequent premature ventricular contractions and/or non-sustained/sustained ventricular tachycardia (VT) or fibrillation (VF).

Results: We identified 65 MVP cases without severe MR (30 [46%] women, 22 [34%] no/trace, 30 [44%] mild, and 13 [21%] moderate MR) and with adequate ECV% measurement. Among these, 38% were classified as AMVP, including two cases of aborted VF arrest, both in premenopausal females. Global ECV% was significantly higher in AMVP vs non-AMVP (31% [27-33] vs 27% [23-30], p = 0.002). In the AMVP group, higher segmental ECV% was not limited to the inferolateral/inferior walls, typically subject to myocardial traction by the prolapsing leaflets/MAD but was more diffuse and involved atypical segments such as the anterior/anterolateral walls (p < 0.05). The association between AMVP and global ECV% was driven by female sex (32% [30-34] vs 27% [25-30], p = 0.002 in females; 28% [23-32] vs 26% [23-30], p = 0.41 in males). ECV% remained independently associated with an increased risk of arrhythmic events, including VT/VF (p < 0.01), even after adjustment for cardiovascular risk factors, MAD, and LGE (p < 0.01).

Conclusion: In MVP without significant MR, interstitial fibrosis by CMR is associated with an increased risk of arrhythmic events, suggesting a primary myopathic process. The selective association between interstitial fibrosis and AMVP in females may explain why severe arrhythmic complications are more prevalent among women.

Background: Concerns exist that long-term cardiac alterations occur after severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, particularly in patients who were hospitalized in the acute phase or who remain symptomatic. This study investigates potential long-term functional and morphological alterations after SARS-CoV-2 infection.

Methods: The authors of this study investigated patients after SARS-CoV-2 infection by using a mobile 1.5T clinical magnetic resonance scanner for cardiac alterations. Cardiac function and dimensions were assessed using a highly efficient cardiac magnetic resonance protocol, which included cine sequences, global longitudinal and circumferential strain assessed by fast-Strain-ENCoded imaging, and T1 and T2 mapping. We assessed symptoms through a questionnaire. Patients were compared with a control group matched for age, gender, body mass index, and body surface area.

Results: Median follow-up time was 395 (192-408) days. The final population included 183 participants (age 48.4 ± 14.3 years, 48.1% male (88/183)). During the acute phase of SARS-CoV-2 infection, 27 patients were hospital-admitted. Forty-two patients reported persistent symptoms (shortness of breath, chest pain, palpitations, or leg edema), and 63 reported impaired exercise tolerance. Left ventricular (LV) functional and morphological parameters were within the normal range. T1- and T2-relaxation times were also within the normal range, indicating that the presence of myocardial edema or fibrosis was unlikely. Persistently symptomatic patients showed a slightly reduced indexed LV stroke volume. Functional parameters remained normal in patients who were hospitalized for SARS-CoV-2, persistently symptomatic, or with ongoing impaired exercise tolerance.

Conclusion: Irrespective of ongoing symptoms or severity of prior illness, patients who have recovered from SARS-CoV-2 infection demonstrate normal functional and morphological cardiac parameters. Long-term cardiac changes due to SARS-CoV-2 infection appear to be rare.