Myocardial T1 Mapping Research Articles

Kiosk 9R-TB-01 - Validation of a Novel FBee-breathing Simultaneous 3D Bright- and Black-blood Anatomical Imaging and Myocardial T2 Mapping Sequence on Healthy Subjects

Kiosk 9R-TB-01 - Validation of a Novel FBee-breathing Simultaneous 3D Bright- and Black-blood Anatomical Imaging and Myocardial T2 Mapping Sequence on Healthy Subjects

Myocardial inflammation in Fabry disease: correlations between myocardial histology, T2 mapping, and troponin

Abstract Background Myocardial inflammation likely plays a key role in cardiac Fabry disease (FD), supported by the frequent observation using cardiac MRI (CMR) of high T2 mapping values, mainly in areas of late gadolinium enhancement, LGE), typically representing oedema, and increased troponin (myocardial injury). Purpose To characterize inflammation in FD cardiomyopathy by comparing myocardial histology, T2 mapping and troponin. Methods Fifteen FD patients (67% females; 51 years old, range 39-62), undergoing 3 tests: biopsy (either RV endomyocardial biopsy, n=10, or myectomy, n=5); CMR (1.5T: cines, LGE, native T1/T2 mapping quantified in the sampling area); and troponin assessment (high sensitivity TnI). Mapping values were compared to local healthy volunteers. Left ventricle hypertrophy (LVH) was defined as either MWT ≥12mm or indexed LV mass above sex specific reference ranges. Tissue was stained using Haematoxylin-Eosin and Azan Mallory trichrome. Inflammatory cell staining used CD68 and CD3 antibodies. An abnormal inflammatory infiltrate was defined according to ESC criteria as ≥14 leukocytes/mm2 (up to 4monocytes/mm2, CD3+T-lymphocytes>7cells/mm2) and its distribution classified as focal (<30% of the specimen), multifocal (30-60%), diffuse (>60%). Results Median LV ejection fraction was 63% (58-67); indexed end diastolic volume 83ml/m2 (68-91). Seven patients had LVH. 8 patients had low native T1 and 6 had infero-lateral LGE. Median septal T2 value was 50ms (47-52) with 3 (all females) above local upper limit value (ULV). TnI was increased in 6 pts (40%; median value 54ng/L [38-128]). Histology showed mild inflammatory infiltrates in 8 pts (46%), none diffuse (focal 4, multifocal 4). Seven were mixed - T lymphocytes and macrophages, one was exclusively macrophages. Inflammatory foci were quiescent (n=5), or associated to myocytes injury not typical of ischemic damage and fibrosis (n=3). None had histologically visible myocardial oedema. Patients with inflammatory infiltrates had higher T2 values (52ms [50-54] vs 47ms [46-51]; p=0.043) but the same troponin (18ng/L [3-82] vs 14ms [3-24], p=0.215) (figure 1). The 3 patients with high T2 all had inflammatory cells associated to histologic myocyte injury (figure 2). Conclusion For the first time we correlate histology with T2 and myocardial injury in FD. In this small study, mild myocardial macrophage/lymphocyte infiltrates are common in FD and are associated to higher T2 values. Abnormal T2 septal elevation is less common (it is known common in the basal inferolateral wall however) and when present, infiltration with histological myocyte damage is found.

Abstract 13430: Cardiovascular Magnetic Resonance Imaging for Comprehensive Risk Assessment in Patients With Aortic Stenosis

Introduction: Precise risk assessment is essential for accurate management of patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). This study aimed to assess the prognostic implications of cardiovascular magnetic resonance (CMR)-derived imaging biomarkers in a large cohort of AS patients. Methods: 145 patients with severe AS underwent CMR imaging before TAVR. Image analyses included myocardial volumes, CMR-feature-tracking derived left and right atrial (LA & RA) as well as left and right ventricular (LV & RV) strain, myocardial T1 mapping as well as late gadolinium enhancement analyses. Cardiovascular (CV) mortality was defined as primary clinical endpoint. Results: Patients with CV death during follow-up had significantly enlarged RV enddiastolic volumes (82.9ml/ml 2 [70.8-96.0] vs. 62.8ml/ml 2 [54.7-76.0], p<0.001) and impaired strain values of all cardiac chambers compared to patients that survived (LV GLS: -18.1% [-13.1- -20.4] vs. -22.5% [-16.1- -27.3], p=0.019; RV GLS: -22.9% [-18.6 - -25.4] vs. -27.9% [-22.9- -32.0], p=0.002; LA Es: 9.5% [7.2 - 15.4] vs. 14.3% [9.0-18.1], p=0.036; RA Es: 12.4% [6.8-14.4] vs. 16.2% [11.2-22.1], p<0.001). RA reservoir strain independently predicted CV mortality after adjusting for other CMR imaging biomarkers and clinical parameters of heart failure. Within patients with high ECV values especially RA strain further identified AS patients at high-risk for CV mortality (p=0.001 on log-rank testing). Conclusion: Comprehensive CMR-imaging allows accurate outcome assessment and additional identification of high-risk groups in AS patients. Especially RA strain emerged as independent predictor for cardiovascular mortality and might serve for future optimized patient management.

Myocardial native T1 mapping and extracellular volume quantification in asymptomatic female carriers of Duchenne muscular dystrophy gene mutations

BackgroundFemale carriers of dystrophin gene mutations (DMD-FC) were previously considered non-manifesting, but in recent decades, cardiomyopathy associated with muscular dystrophy and myocardial fibrosis has been described. Our study aimed to assess prospectively myocardial fibrosis in asymptomatic DMD-FC compared to a sex-matched control group (CG) with similar age distribution using native T1 mapping and extracellular volume (ECV) quantification by cardiovascular magnetic resonance (CMR) imaging.Materials and methods38 DMD-FC with verified genetic mutation and 22 healthy volunteers were included. Using CMR, native T1 relaxation time and ECV quantification were determined in each group. Late gadolinium enhancement (LGE) was assessed in all cases.ResultsThere were 38 DMD-FC (mean age 39.1 ± 8.8 years) and 22 healthy volunteers (mean age 39.9 ± 12.6 years) imagined by CMR. The mean global native T1 relaxation time was similar for DMD-FC and CG (1005.1 ± 26.3 ms vs. 1003.5 ± 25.0 ms; p-value = 0.81). Likewise, the mean global ECV value was also similar between the groups (27.92 ± 2.02% vs. 27.10 ± 2.89%; p-value = 0.20). The segmental analysis of mean ECV values according to the American Heart Association classification did not show any differences between DMD-FC and CG. There was a non-significant trend towards higher mean ECV values of DMD-FC in the inferior and inferolateral segments of the myocardium (p-value = 0.075 and 0.070 respectively).ConclusionThere were no statistically significant differences in the mean global and segmental native T1 relaxation times and the mean global or segmental ECV values. There was a trend towards higher segmental mean ECV values of DMD-FC in the inferior and inferolateral walls of the myocardium.

Diagnostic Value of T1 Mapping in Detecting Iron Overload in Indian Patients with Thalassemia Major: A Comparison with T2* Mapping.

Purpose T2* is the gold standard for iron quantification in liver as well as myocardium. In this study, we evaluated the diagnostic accuracy of myocardial T1 mapping for the assessment of myocardial iron overload (MIO) as compared to the T2* mapping in patients with thalassemia major (TM). Methods Consecutive TM patients attending the thalassemia clinic were prospectively enrolled. Magnetic resonance imaging was performed on a 1.5 T scanner (Siemens Healthineers, Germany) using a gradient echo T2* as well as a T1 mapping (MOLLI) sequence done at a mid-ventricular short-axis single 8 mm slice of the left ventricle. Values were analyzed by manually drawing a region of interest in the mid-septum. T2*less than 20ms was used as the cutoff for significant MIO. Results One-hundred three patients (58 males, mean age: 17 ± 7.8 years, mean ferritin: 2009.5 µg/L) underwent cardiovascular magnetic resonance. Median T2* of myocardium was 33.45ms. Nineteen patients (18.4%) had T2*less than 20ms. T1 value was low (<850ms) in all the patients with T2* less than 20 ms. Receiver operating characteristic curve analysis revealed the best cutoff of native T1 mapping value as 850 ms which had high specificity (95.2%), sensitivity (94.2%) and negative predictive value (98.8%) for T2* less than 20ms. There was excellent agreement between T1 and T2* for diagnosis of MIO (Kappa-0.848, p <0.001). We did not find any patient who had normal T1 mapping values but had MIO on T2*. Conclusion T1 and T2* correlate well and normal T1 values may rule out presence of MIO. T1 mapping can act as additional imaging marker for MIO and may be helpful in centers with nonavailability or limited experience of T2*.

Myocardial T1 mapping by cardiac magnetic resonance imaging shows early myocardial changes in treatment-naive patients with active rheumatoid arthritis and positive autoantibodies.

We aimed to study whether myocardial changes are already detectable by cardiac magnetic resonance (CMR) imaging at the time of rheumatoid arthritis (RA) diagnosis. This single-centre prospective study included 39 treatment-naive patients with early rheumatoid arthritis (ERA, symptom duration <1 year) without any history of heart disease, and 38 age- and sex-matched healthy volunteers. The disease severity was assessed with clinical evaluation (Disease Activity Score-28 for Rheumatoid Arthritis with CRP (DAS28-CRP) score) and serological testing (rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA)). The ERA patients were classified into group A (DAS28-CRP score ≥3.2, positive RF and ACPA; n=17) and group B (not fulfilling the group A criteria). The ERA patients and healthy controls underwent 1.5T CMR. Group A patients had significantly higher myocardial global T1 relaxation times than the healthy controls, 987 [965, 1003] ms vs. 979 [960, 991] ms (median [IQR]; p=0.041). A significant difference in T1 was found in the basal, mid inferior and mid anterolateral segments. In a multivariate analysis, prolonged global T1 relaxation time was independently associated with female sex (95% CI [5.62, 51.31] ms, p=0.016), and group A status (95% CI [4.65, 39.01] ms p=0.014). At the time of diagnosis, ERA patients with a higher disease activity (DAS28-CRP score ≥3.2) and both positive RF and ACPA showed prolonged T1 relaxation times in basal myocardial segments. These segments could be most susceptible to the development of myocardial fibrosis, and a segmental reporting style could be useful when estimating the first signs of myocardial fibrosis.

Advanced CMR Techniques in Anderson-Fabry Disease: State of the Art.

Anderson-Fabry disease (AFD) is a rare multisystem X-linked lysosomal storage disorder caused by α-galactosidase A enzyme deficiency. Long-term cardiac involvement in AFD results in left ventricular hypertrophy and myocardial fibrosis, inducing several complications, mainly arrhythmias, valvular dysfunction, and coronary artery disease. Cardiac magnetic resonance (CMR) represents the predominant noninvasive imaging modality for the assessment of cardiac involvement in the AFD, being able to comprehensively assess cardiac regional anatomy, ventricular function as well as to provide tissue characterization. This review aims to explore the role of the most advanced CMR techniques, such as myocardial strain, T1 and T2 mapping, perfusion and hybrid imaging, as diagnostic and prognostic biomarkers.

Features of myocardial characteristics of patients with acute ST-segment elevation myocardial infarction with diabetes mellitus as assessed by contrast-enhanced cardiac magnetic resonance imaging

Introduction. The presence of diabetes mellitus in patients with acute infarction significantly worsens short- and long-term prognosis, but the features of the course of the infarction in this category of patients have not been fully studied.Objective. To compare clinical, functional and structural myocardial characteristics of patients with acute ST-segment elevation myocardial infarction with and without diabetes mellitus.Materials and methods. The study included 91 patients with revascularized ST-segment elevation myocardial infarction (41 patients with diabetes mellitus). All patients underwent cardiac MRI with contrast, including myocardial T1 mapping, tissue analysis of left ventricular myocardium with determination of infarct zone, heterogeneous zone, edema zone, pre- and post-contrast T1 values, extracellular volume values of healthy myocardium and infarct zone.Results. The presence of diabetes in patients with AMI was associated with increased EDV LV: 153 ± 38 and 181 ± 58 ml (p = 0.007), increased ESV LV: 76 ml [54–93] and 87 ml [71–122] (p = 0.035). Infarct size was significantly larger in patients with diabetes than in those without diabetes: 37 ± 15 g (95% CI: 33–41) and 47 ± 21 g (95% CI: 40–53), p = 0.017. Patients with acute infarction and diabetes mellitus had higher extracellular volume values in both healthy myocardium: 24% [22–27] and 28% [24–30], p = 0.002, and in the infarct zone: 48% [40–58] and 58% [50–61], p = 0.016.Conclusions. In patients with ST-segment elevation myocardial infarction with diabetes mellitus, the infarct size, the edema area, and the value of the extracellular volume fraction both in the infarct area and in the preserved myocardium were larger than in patients without diabetes, which may underlie the development of myocardial dysfunction and further progression of heart failure.

Improved Simultaneous Multi-slice imaging with Composition of k-space Interpolations (SMS-COOKIE) for myocardial T1 mapping.

The aim of this study is to develop and evaluate a regularized Simultaneous Multi-Slice (SMS) reconstruction method for improved Cardiac Magnetic Resonance Imaging (CMR). The proposed reconstruction method, SMS with COmpOsition of k-space IntErpolations (SMS-COOKIE) combines the advantages of Iterative Self-consistent Parallel Imaging Reconstruction (SPIRiT) and split slice-Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA), while allowing regularization for further noise reduction. The proposed SMS-COOKIE was implemented with and without regularization, and validated using a Saturation Pulse-Prepared Heart rate Independent inversion REcovery (SAPPHIRE) myocardial T1 mapping sequence. The performance of the proposed reconstruction method was compared to ReadOut (RO)-SENSE-GRAPPA and split slice-GRAPPA, on both retrospectively and prospectively three-fold SMS-accelerated data with an additional two-fold in-plane acceleration. All SMS reconstruction methods yielded similar T1 values compared to single band imaging. SMS-COOKIE showed lower spatial variability in myocardial T1 with significant improvement over RO-SENSE-GRAPPA and split slice-GRAPPA (P < 10-4). The proposed method with additional locally low rank (LLR) regularization reduced the spatial variability, again with significant improvement over RO-SENSE-GRAPPA and split slice-GRAPPA (P < 10-4). In conclusion, improved reconstruction quality was achieved with the proposed SMS-COOKIE, which also provided lower spatial variability with significant improvement over split slice-GRAPPA.

Hepatic t1 mapping: a new easily obtained biomarker for heart failure patients undergoing cardiac magnetic resonance

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Hepatic venous pressure overload and subsequent liver damage are frequent in patients with Chronic Heart Failure (CHF) but are difficult to quantify except in the late stages of disease. Myocardial T1 mapping is now commonly performed in patients undergoing cardiac magnetic resonance (CMR), with short axis images usually intercepting the liver, therefore allowing the opportunistic measurement of hepatic T1 values. Purpose The aim of this study was to quantify hepatic T1 values in HF patients undergoing CMR, and to assess its clinical and prognostic significance as a biomarker in this setting. Methods Consecutive patients with CHF (LVEF ≤ 50%) who underwent CMR at a single centre since Jan2019 were retrospectively identified. Those with known chronic liver disease, cardiac amyloidosis or suspected alcoholic cardiomyopathy were excluded. Native myocardial T1 mapping [MOLLI 5(3)3 sequence] basal short axis images were used to measure hepatic T1, with the region of interest drawn in the liver, avoiding organ vessels. A control group of subjects without known cardiovascular disease (n=57) was used to define the limits of normality for hepatic T1 values. The clinical significance of hepatic T1 values was assessed by its relationship with markers of right-sided CHF, and its prognostic value by the association with cardiovascular mortality. Results A total of 267 patients (mean age 62±15 years, 69% men, 38% with ischemic cardiomyopathy) were included. Median LVEF was 35% (IQR 26 – 44%) and median RVEF was 51% (IQR 40 – 59%). Overall, 46 patients (17%) had hepatic T1 values above 684 ms (the upper limit of normal for controls). Patients with elevated hepatic T1 had significantly higher RV volumes and lower RVEF (all p values &amp;lt;0.03). Hepatic T1 values were significantly higher in patients with RVEF&amp;lt;45% and in those with moderate or severe tricuspid regurgitation (Figure 1), and were also inversely correlated with RVEF (Spearman R −0.20, p&amp;lt;0.001). During a median follow-up period of 17 months (IQR 11–24), there were 11 cardiovascular deaths. Elevated hepatic T1 was associated with an increased risk of this endpoint (HR 3.04, 95%CI 1.02 – 9.11, p = 0.047). Conclusions Hepatic T1 values can be easily measured in standard myocardial T1 maps, are associated with markers of right-sided heart failure, and have prognostic value in patients with HF. Further studies are warranted to assess the potential clinical usefulness of this new biomarker.

Motion-corrected model-based reconstruction for 2D myocardial T1 mapping.

To allow for T1 mapping of the myocardium within 2.3 s for a 2D slice utilizing cardiac motion-corrected, model-based image reconstruction. Golden radial data acquisition is continuously carried out for 2.3 s after an inversion pulse. In a first step, dynamic images are reconstructed which show both contrast changes due to T1 recovery and anatomical changes due to the heartbeat. An image registration algorithm with a signal model for T1 recovery is applied to estimate non-rigid cardiac motion. In a second step, estimated motion fields are applied during an iterative model-based T1 reconstruction. The approach was evaluated in numerical simulations, phantom experiments and in in-vivo scans in healthy volunteers. The accuracy of cardiac motion estimation was shown in numerical simulations with an average motion field error of 0.7 ± 0.6 mm for a motion amplitude of 5.1 mm. The accuracy of T1 estimation was demonstrated in phantom experiments, with no significant difference (p = 0.13) in T1 estimated by the proposed approach compared to an inversion-recovery reference method. In vivo, the proposed approach yielded 1.3 × 1.3 mm T1 maps with no significant difference (p = 0.77) in T1 and SDs in comparison to a cardiac-gated approach requiring 16 s scan time (i.e., seven times longer than the proposed approach). Cardiac motion correction improved the precision of T1 maps, shown by a 40% reduced SD. We have presented an approach that provides T1 maps of the myocardium in 2.3 s by utilizing both cardiac motion correction and model-based T1 reconstruction.

Rapidly reversible acute neurological, renal, and cardiac impairment during malignant hypertension

BackgroundMalignant hypertension is a model of the rapid changes that a high afterload and renin-angiotensin levels can induce on target organs such as the heart. We present a case of a young man affected by malignant hypertension with multi-organ involvement who showed quick remission after adequate antihypertensive treatment.Case summaryA 41-year-old jazz pianist with a family history of coronary artery disease presented to the emergency department for asthenia and epigastric pain, associated with right eye visual impairment. No neurological symptoms. An echocardiogram showed left ventricular hypertrophy with severe impairment of ejection fraction (22%) due to global hypokinesia. There was renal insufficiency (creatinine 2.51 mg/dl, eGFR 34 ml/min, HS Troponin T 127 pg/dl, NT pro-BNP 22,672 pg/ml, CRP 32 mg/L, sodium 129 mEq/L with normal kaliemia. The following day, anterior T wave inversion was observed in the electrocardiogram. At a cardiac magnetic resonance. Concentric hypertrophy of the left ventricle was observed with normal myocardial T1 mapping values (1100 ± 38 ms), ruling out Fabry’s disease. There was no obvious myocardial edema at T2 weighted. The viral panel for acute myocarditis resulted in negative. After the exclusion of all possible secondary causes, malignant essential hypertension was the final diagnosis, and additional tests confirmed multi-organ damage. An ophthalmological examination demonstrated hypertensive retinopathy with hemorrhages, cottony exudates, and macular lipid exudation, especially in the right eye. A brain MRI showed small areolas of T2 hyperintensity in the white matter of both cerebral hemispheres, suggestive of chronic microangiopathy, and left nuclear micro lacunar ischemia.The patient was treated with full-dose calcium channel blockers (amlodipine 10 mg), beta-blockers (bisoprolol 10 mg), alpha2 agonists (slow-release clonidine patch), selective a1 blocker (doxazosine 16 mg), and furosemide 50 mg. After the exclusion of renal stenosis and improvement of renal function, Ramipril was added up to a final dose of 10 mg daily. In parallel with the achievement of a satisfactory blood pressure control, visual impairment disappeared with a reduction of retinal ischemic exudates and hemorrhages at the ophthalmological follow-up assessment.At the time of discharge, an echocardiographic re-evaluation confirmed concentric hypertrophy of the left ventricle with markedly reduced wall thicknesses, with a partial recovery in left ventricular ejection function (EF 44%).Six months after discharge, the patient is in good general condition under optimal medical therapy (without furosemide) with normalized blood pressure values (130–140/80 mmHg). At 6 months from discharge, creatinine was only mildly increased (1.5 mg/dl, eGFR 59.5 ml/min) and NT-pro BNP nearly normalized (452 pg/ml).DiscussionMalignant hypertension is a cardiovascular emergency and requires immediate and careful intervention to lower blood pressure and reduce organ injury. It is an exclusion diagnosis that can be advanced once the causes of secondary hypertension have been excluded. Remission of organ injury is possible and might be rapid under adequate antihypertensive treatment, but patients require a close follow-up.

Histopathologic Validation of Stress T1 Mapping in Myocardial Ischemia: Another Step toward Clinical Translation?

Histopathologic Validation of Stress T1 Mapping in Myocardial Ischemia: Another Step toward Clinical Translation?

Detection of Early Diffuse Myocardial Fibrosis and Inflammation in Chagas Cardiomyopathy with T1 Mapping and Extracellular Volume

Purpose To evaluate myocardial T1 mapping and extracellular volume (ECV) parameters in different stages of Chagas cardiomyopathy and determine whether they are predictive of disease severity and prognosis. Materials and Methods Prospectively enrolled participants (July 2013 to September 2016) underwent cine and late gadolinium enhancement (LGE) cardiac MRI and T1 mapping with a precontrast (native) or postcontrast modified Look-Locker sequence. The native T1 and ECV values were measured among subgroups that were based on disease severity (indeterminate, Chagas cardiomyopathy with preserved ejection fraction [CCpEF], Chagas cardiomyopathy with midrange ejection fraction [CCmrEF], and Chagas cardiomyopathy with reduced ejection fraction [CCrEF]). Cox proportional hazards regression and the Akaike information criterion were used to determine predictors of major cardiovascular events (cardioverter defibrillator implant, heart transplant, or death). Results In 107 participants (90 participants with Chagas disease [mean age ± SD, 55 years ± 11; 49 men] and 17 age- and sex-matched control participants), the left ventricular (LV) ejection fraction and the extent of focal and diffuse or interstitial fibrosis were correlated with disease severity. Participants with CCmrEF and participants with CCrEF showed significantly higher global native T1 and ECV values than participants in the indeterminate, CCpEF, and control groups (T1: 1072 msec ± 34 and 1073 msec ± 63 vs 1010 msec ± 41, 1005 msec ± 69, and 999 msec ± 46; ECV: 35.5% ± 3.6 and 35.0% ± 5.4 vs 25.3% ± 3.5, 28.2% ± 4.9, and 25.2% ± 2.2; both P < .001). Remote (LGE-negative areas) native T1 and ECV values were also higher (T1: 1056 msec ± 32 and 1071 msec ± 55 vs 1008 msec ± 41, 989 msec ± 96, and 999 msec ± 46; ECV: 30.2% ± 4.7 and 30.8% ± 7.4 vs 25.1% ± 3.5, 25.1% ± 3.7, and 25.0% ± 2.2; both P < .001). Abnormal remote ECV values (>30%) occurred in 12% of participants in the indeterminate group, which increased with disease severity. Nineteen combined outcomes were observed (median follow-up time: 43 months), and a remote native T1 value greater than 1100 msec was independently predictive of combined outcomes (hazard ratio, 12 [95% CI: 4.1, 34.2]; P < .001). Conclusion Myocardial native T1 and ECV values were correlated with Chagas disease severity and may serve as markers of myocardial involvement in Chagas cardiomyopathy that precede LGE and LV dysfunction. Keywords: MRI, Cardiac, Heart, Imaging Sequences, Chagas Cardiomyopathy Supplemental material is available for this article. © RSNA, 2023

Pilot study to establish the myocardium native T1 mapping reference values in 1.5 Tesla cardiac magnetic resonance of healthy Malaysians

BackgroundCardiac magnetic resonance (CMR) is a powerful and robust imaging modality with the capability for tissue characterisation by quantifying the intrinsic magnetic properties of tissues. The current international consensus recommendation is to determine the local normal T1 mapping value. Recent advancement suggests pooled data or benchmarking of CMR mapping reference values. We present the adult myocardial native T1 mapping value of a common MR acquisition in healthy Malaysians who are predominantly brown skin Asians.MethodsThis is a prospective, cross-sectional study in a single centre. CMR was performed on a 1.5 T MR using 5(3s)3 MOLLI sequence with motion correction, TE = 1.31 ms, TR = 2.78 ms. The analysis of the mid-septal T1 value was done using third-party software (CVi42) and the OsiriX software by two blinded cardiac radiologists.ResultsA total of 51 eligible adults were recruited of which 1 was excluded due to incidental finding of moderate mitral regurgitation. The mean age was 30 years ± 7.0, the majority (64%) was female, the median heart rate was 72 ± 20 bpm and mean the BSA was 1.6 ± 0.1 m2. The ethnicity distribution is Malay 76%, Indian 12%, Chinese 8% and Sabahan 4%. The normal range for mid-septum myocardial T1 using CVi42 was 1012 ± 33 ms and using OsiriX was 1018 ± 37 ms. There is no correlation observed against gender, ethnicity and heart rate. The moderate correlation observed with age is not gender specified. The interobserver reliability was good (coefficient 0.813).ConclusionsFor T1 mapping to be applied clinically, it is imperative to determine the local normal value as recommended by international consensus. The first-ever database on native T1 mapping for 1.5 T CMR reference value for Malaysians who are predominantly brown skin Asians is provided in this pilot study.

Quantitative myocardial T2 mapping adds value to Japanese circulation society diagnostic criteria for active cardiac sarcoidosis.

Noninvasive identification of active myocardial inflammation in patients with cardiac sarcoidosis plays a key role in management but remains elusive. T2 mapping is a proposed solution, but the added value of quantitative myocardial T2 mapping for active cardiac sarcoidosis is unknown. Retrospective cohort analysis of 56 sequential patients with biopsy-confirmed extracardiac sarcoidosis who underwent cardiac MRI for myocardial T2 mapping. The presence or absence of active myocardial inflammation in patients with CS was defined using a modified Japanese circulation society criteria within one month of MRI. Myocardial T2 values were obtained for the 16 standard American Heart Association left ventricular segments. The best model was selected using logistic regression. Receiver operating characteristic curves and dominance analysis were used to evaluate the diagnostic performance and variable importance. Of the 56 sarcoidosis patients included, 14 met criteria for active myocardial inflammation. Mean basal T2 value was the best performing model for the diagnosis of active myocardial inflammation in CS patients (pR2 = 0.493, AUC = 0.918, 95% CI 0.835-1). Mean basal T2 value > 50.8ms was the most accurate threshold (accuracy = 0.911). Mean basal T2 value + JCS criteria was significantly more accurate than JCS criteria alone (AUC = 0.981 vs. 0.887, p = 0.017). Quantitative regional T2 values are independent predictors of active myocardial inflammation in CS and may add additional discriminatory capability to JCS criteria for active disease.

Chronic troponin elevation assessed by myocardial T1 mapping in patients with stable coronary artery disease.

Cardiac troponin detected with sensitive assays can be chronically elevated, in the absence of unstable coronary syndromes. In patients with chronic coronary artery disease, clinically silent ischemic episodes may cause chronic troponin release. T1 mapping is a cardiovascular magnetic resonance technique useful in quantitative cardiac tissue characterization. We selected patients with anatomically and functionally normal hearts to investigate associations between chronic troponin release and myocardial tissue characteristics assessed by T1 mapping. We investigated the relationship between cardiac troponin I concentrations and cardiovascular magnetic resonance T1 mapping parameters in patients with stable coronary artery disease enrolled in MASS V study before elective revascularization. Participants had no previous myocardial infarction, negative late gadolinium enhancement, normal left ventricular function, chamber dimensions and wall thickness. A total of 56 patients were analyzed in troponin tertiles: nativeT1 and extracellular volume (ECV) values (expressed as means ± standard deviations) increased across tertiles: nativeT1 (1006 ± 27 ms vs 1016 ± 27 ms vs 1034 ± 37 ms, ptrend = 0.006) and ECV (22 ± 3% vs 23 ± 1.9% vs 25 ± 3%, ptrend = 0.007). Cardiac troponin I concentrations correlated with native T1(R = 0.33, P = .012) and ECV (R = 0.3, P = .025), and were independently associated with nativeT1 (P = .049) and ventricular mass index (P = .041) in multivariable analysis. In patients with chronic coronary artery disease and structurally normal hearts, troponin I concentrations correlated with T1 mapping parameters, suggesting that diffuse edema or fibrosis scattered in normal myocardium might be associated with chronic troponin release.

Open-source myocardial T1 mapping with simultaneous multi-slice acceleration: Combining an auto-calibrated blipped-bSSFP readout with VERSE-MB pulses.

Enabling fast and accessible myocardial T1 mapping is crucial for extending its clinical application. We introduce Open-MOLLI-SMS combining simultaneous multi-slice (SMS) with auto-calibration and variable-rate selective excitation (VERSE)-multiband pulses to obtain all slices in a fast single-shot T1 mapping sequence. Open-MOLLI-SMS was developed by integrating SMS with the open-source method Open-MOLLI previously implemented in Pulseq. Three methods were integrated for Open-MOLLI-SMS: (1) auto-calibration blip patterns to ensure consistency between the data and coil information; (2) a blipped-balanced SSFP (bSSFP) readout to induce controlled aliasing in parallel imaging shifts without disturbing the bSSFP frequency response; and (3) a VERSE-multiband pulse for minimizing the achievable TR and the specific absortion rate (SAR) impact of SMS. Two (SMS2) or three (SMS3) slices were excited simultaneously and encoded with an in-plane acceleration factor of 2. Experiments were performed in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology phantom and five healthy volunteers. Phantom results show accurate T1 estimates for reference values between 400 to 2200 ms. Artifacts were visible for Open-MOLLI-SMS3 but not replicated in vivo. In vivo Open-MOLLI-SMS (T1 SMS2 = 993 ± 10 ms; T1 SMS3 = 1031 ± 17 ms) provided similar values to mean T1 single-band Open-MOLLI estimates (T1 Open-MOLLI = 1005 ± 47 ms). Open-MOLLI-SMS2 provided the closest estimates to the reference. This proof-of-principle implementation study demonstrates the feasibility of speeding up T1 -mapping acquisitions and increasing coverage by combining auto-calibration strategies with a blipped-bSFFP readout and VERSE multiband RF excitation pulses. The proposed methodology was built on the Open-MOLLI mapping sequence, which provides a fast means for prototyping and enables open-source sharing of the method.

Myocardial T1 Mapping to Identify Risk of Sudden Death in Heart Failure

HomeRadiologyRecently Published PreviousNext Reviews and CommentaryEditorialMyocardial T1 Mapping to Identify Risk of Sudden Death in Heart FailureHajime Sakuma Hajime Sakuma Author AffiliationsFrom the Department of Radiology, Mie University Hospital, 2-174 Edobashi, Tsu, Mie 5148507, Japan.Address correspondence to the author (email: [email protected]).Hajime Sakuma Published Online:Mar 14 2023https://doi.org/10.1148/radiol.230323MoreSectionsFull textPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In

Joint Cardiac T1 Mapping and Cardiac Cine Using Manifold Modeling

The main focus of this work is to introduce a single free-breathing and ungated imaging protocol to jointly estimate cardiac function and myocardial T1 maps. We reconstruct a time series of images corresponding to k-space data from a free-breathing and ungated inversion recovery gradient echo sequence using a manifold algorithm. We model each image in the time series as a non-linear function of three variables: cardiac and respiratory phases and inversion time. The non-linear function is realized using a convolutional neural networks (CNN) generator, while the CNN parameters, as well as the phase information, are estimated from the measured k-t space data. We use a dense conditional auto-encoder to estimate the cardiac and respiratory phases from the central multi-channel k-space samples acquired at each frame. The latent vectors of the auto-encoder are constrained to be bandlimited functions with appropriate frequency bands, which enables the disentanglement of the latent vectors into cardiac and respiratory phases, even when the data are acquired with intermittent inversion pulses. Once the phases are estimated, we pose the image recovery as the learning of the parameters of the CNN generator from the measured k-t space data. The learned CNN generator is used to generate synthetic data on demand by feeding it with appropriate latent vectors. The proposed approach capitalizes on the synergies between cine MRI and T1 mapping to reduce the scan time and improve patient comfort. The framework also enables the generation of synthetic breath-held cine movies with different inversion contrasts, which improves the visualization of the myocardium. In addition, the approach also enables the estimation of the T1 maps with specific phases, which is challenging with breath-held approaches.