Late Gadolinium Enhancement Technique Research Articles

Reducing cardiac implantable electronic device–induced artefacts in cardiac magnetic resonance imaging

ObjectivesCardiac implantable electronic device (CIED)–induced metal artefacts possibly significantly diminish the diagnostic value of magnetic resonance imaging (MRI), particularly cardiac MR (CMR). Right-sided generator implantation, wideband late-gadolinium enhancement (LGE) technique and raising the ipsilateral arm to the generator during CMR scanning may reduce the CIED-induced image artefacts. We assessed the impact of generator location and the arm-raised imaging position on the CIED-induced artefacts in CMR.MethodsWe included all clinically indicated CMRs performed on patients with normal cardiac anatomy and a permanent CIED with endocardial pacing leads between November 2011 and October 2019 in our institution (n = 171). We analysed cine and LGE sequences using the American Heart Association 17-segment model for the presence of artefacts.ResultsRight-sided generator implantation and arm-raised imaging associated with a significantly increased number of artefact-free segments. In patients with a right-sided pacemaker, the median percentage of artefact-free segments in short-axis balanced steady-state free precession LGE was 93.8% (IQR 9.4%, n = 53) compared with 78.1% (IQR 20.3%, n = 58) for left-sided pacemaker (p < 0.001). In patients with a left-sided implantable cardioverter-defibrillator, the median percentage of artefact-free segments reached 87.5% (IQR 6.3%, n = 9) using arm-raised imaging, which fell to 62.5% (IQR 34.4%, n = 9) using arm-down imaging in spoiled gradient echo short-axis cine (p = 0.02).ConclusionsArm-raised imaging represents a straightforward method to reduce CMR artefacts in patients with left-sided generators and can be used alongside other image quality improvement methods. Right-sided generator implantation could be considered in CIED patients requiring subsequent CMR imaging to ensure sufficient image quality.Key Points• Cardiac implantable electronic device (CIED)–induced metal artefacts may significantly diminish the diagnostic value of an MRI, particularly in cardiac MRIs.• Raising the ipsilateral arm relative to the CIED generator is a cost-free, straightforward method to significantly reduce CIED-induced artefacts on cardiac MRIs in patients with a left-sided generator.• Right-sided generator implantation reduces artefacts compared with left-sided implantation and could be considered in CIED patients requiring subsequent cardiac MRIs to ensure adequate image quality in the future.

Role of Cardiac MRI Imaging of Focal and Diffuse Inflammation and Fibrosis in Cardiomyopathy Patients Who Have Pacemakers/ICD Devices.

This focused report aims to discuss and summarize the use of conventional and emerging methods using cardiovascular magnetic resonance (CMR) imaging in cardiomyopathy patients with implanted cardiac devices to identify diffuse and focal inflammation and fibrosis. Many cardiomyopathy patients with diffuse and focal myocardial fibrosis have a unique need for cardiac imaging that is complicated by cardiovascular implantable electronic devices (CIEDs). CMR imaging can accurately image myocardial fibrosis and inflammation using T1 mapping and late gadolinium enhancement (LGE) imaging. CMR imaging in CIED patients, however, has been limited due to severe imaging artifacts associated with the devices. The emergence of wideband imaging variants of LGE and T1 mapping techniques can successfully reduce or eliminate CIED artifacts for the evaluation of myocardial substrate in cardiomyopathy patients. Wideband imaging variants of LGE and T1 mapping techniques provide new tools for imaging focal and diffuse fibrosis and imaging in cardiomyopathy patients with implanted cardiac devices. These emerging techniques have the potential for great impact in clinical care of such patients as well as clinical research where imaging endpoints are desired.

Relationship between pancreatic iron overload, glucose metabolism and cardiac complications in sickle cell disease: An Italian multicentre study

Evidence about the cross-talk between iron, glucose metabolism, and cardiac disease is increasing. We aimed to explore the link of pancreatic iron by Magnetic Resonance Imaging (MRI) with glucose metabolism and cardiac complications (CC) in sickle cell disease (SCD) patients. We considered 70 SCD patients consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia Network. Iron overload was quantified by R2* technique and biventricular function by cine images. Macroscopic myocardial fibrosis was evaluated by late gadolinium enhancement technique. Glucose metabolism was assessed by the oral glucose tolerance test. Patients with an altered glucose metabolism showed a significantly higher pancreas R2* than patients with normal glucose metabolism. Pancreatic siderosis emerged as a risk factor for the development of metabolic alterations (OddsRatio 8.25, 95%confidence intervals 1.51-45.1; p=.015). Global pancreas R2* values were directly correlated with mean serum ferritin levels and liver iron concentration. Global pancreas R2* was not significantly associated with global heart R2* and macroscopic myocardial fibrosis. Patients with history of CC showed a significantly higher global pancreas R2* than patients with no CC. Our findings support the evaluation of pancreatic R2* by MRI in SCD patients to prevent the development of metabolic and cardiac disorders.

Cardiac magnetic resonance imaging and the myocardium : Differentiation between vital and nonvital tissue

Cardiac magnetic resonance (cMR), awell-established imaging tool, is indispensable in the diagnosis and management of cardiovascular disease. Given its high spatial resolution and ability to characterize tissue, cMR represents the gold standard in determining myocardial viability. Gadolinium-based contrast-enhanced cMR can accurately identify myocardial scars and fibrosis in the ventricle and the atria, and differentiate it from normal myocardium. Gadolinium is an extracellular molecule which has been shown to be safe and beneficial in magnetic resonance imaging (MRI). Due to the larger extracellular space in myocardial scars, there is more uptake (wash-in) and slower elimination (wash-out) of gadolinium in those areas as opposed to normal myocardium. When imaged several minutes after intravenous administration of gadolinium, nonviable myocardial areas appear brighter than viable myocardium. The use of late-gadolinium enhancement (LGE) technique in assessing myocardial viability has been shown to highly correlate with histological examinations. Furthermore, this technique is highly reproducible and has very high intra- and interobserver agreement. Extent of LGE after myocardial infarction predicts the occurrence of adverse cardiovascular events. Moreover, LGE is highly accurate in predicting functional recovery of dysfunctional myocardial segments in patients undergoing revascularization and consequently has akey role in guiding revascularization procedures. In addition, use of LGE in the identification of myocardial fibrosis or myocardial damage in inflammatory myocardial disease helps to differentiate the type of cardiomyopathy and to predict sudden cardiac death among patients with heart failure. The role of LGE-MRI in the field of electrophysiology through recognition of different substrate for arrythmias and guiding the ablation therapy is steadily increasing and has fundamentally changed our understanding of atrial myopathy.

Link between Genotype and Multi-Organ Iron and Complications in Children with Transfusion-Dependent Thalassemia.

We evaluated the impact of the genotype on hepatic, pancreatic and myocardial iron content, and on hepatic, cardiac and endocrine complications in children with transfusion-dependent β-thalassemia (β-TDT). We considered 68 β-TDT patients (11.98 ± 3.67 years, 51.5% females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia network. Iron overload was quantified by T2* technique and biventricular function by cine images. Replacement myocardial fibrosis was evaluated by late gadolinium enhancement technique. Three groups of patients were identified: homozygous β+ (N = 19), compound heterozygous β0β+ (N = 24), and homozygous β0 (N = 25). The homozygous β0 group showed significantly lower global heart and pancreas T2* values than the homozygous β+ group. Compared to patients with homozygous β+ genotype, β0β+ as well as β0β0 patients were more likely to have pancreatic iron overload (odds ratio = 6.53 and 10.08, respectively). No difference was detected in biventricular function parameters and frequency of replacement fibrosis. No patient had cirrhosis/fibrosis, diabetes or heart failure, and the frequency of endocrinopathies was comparable among the groups. In pediatric β-TDT patients, there is an association between genotype and cardiac and pancreatic iron overload. The knowledge of patients’ genotype can be valuable in predicting some patients’ phenotypic features and in helping the clinical management of β-TDT patients.

Dark-blood late gadolinium-enhancement cardiac magnetic resonance imaging for myocardial scar detection based on simplified timing scheme: single-center experience in patients with suspected coronary artery disease.

This study aims to examine scar detectability using dark-blood late gadolinium enhancement (LGE) with simplified timing scheme and fixed parameters comparing to two conventional bright-blood approaches in patients with known or suspected coronary artery disease. Three LGE techniques were performed in all patients with known or suspected coronary artery disease at 3 T: dark blood two-dimensional (2D) phase-sensitive inversion recovery (PSIR) preceded with a T2-preparation pulse (DB-LGE), conventional three-dimensional (3D) gradient-echo inversion recovery (3D-IR) and conventional 2D PSIR. Timing parameters in DB-LGE were tested in five clinically confirmed coronary artery disease patients with scars and fixed for the rest of the study. Two independent readers evaluated images at both patient and segment levels. Image quality and contrast ratio between scar and adjacent tissues were assessed. Concordance between the three techniques and detection rate based on expert consensus were reported. Forty-six patients were recruited in the study (average age 66.8 years, 69.6% male). DB-LGE demonstrated superior image quality (P=0.001 vs. 3D-IR) and scar-to-blood contrast ratio (P<0.001 vs. 3D-IR and PSIR). Among 41 patients with suspected coronary artery disease, myocardial scar was present in 30 patients (73.2%), all detected by DB-LGE, yielding a detection rate of 100% compared to 93.3% and 96.7% for bright-blood 3D-IR and PSIR. For subendocardial scar detection among 656 segments, DB-LGE had a detection rate of 99.4% compared to 57.8% for 3D-IR and 61.0% for PSIR (both P<0.001). DB-LGE improves detection of myocardial scar compared with conventional bright-blood LGE techniques, particularly of subendocardial scar.

The 2020 "Padua Criteria" for Diagnosis and Phenotype Characterization of Arrhythmogenic Cardiomyopathy in Clinical Practice.

Arrhythmogenic Cardiomyopathy (ACM) is a heredo-familial cardiac disease characterized by fibro-fatty myocardial replacement and increased risk of sudden cardiac death. The diagnosis of ACM can be challenging due to the lack of a single gold-standard test: for this reason, it is required to satisfy a combination of multiple criteria from different categories including ventricular morpho-functional abnormalities, repolarization and depolarization ECG changes, ventricular arrhythmias, tissue characterization findings and positive family history/molecular genetics. The first diagnostic criteria were published by an International Task Force (ITF) of experts in 1994 and revised in 2010 with the aim to increase sensitivity for early diagnosis. Limitations of the 2010 ITF criteria include the absence of specific criteria for left ventricle (LV) involvement and the limited role of cardiac magnetic resonance (CMR) as the use of the late gadolinium enhancement technique for tissue characterization was not considered. In 2020, new diagnostic criteria (“the Padua criteria”) were proposed. The traditional organization in six categories of major/minor criteria was maintained. The criteria for identifying the right ventricular involvement were modified and a specific set of criteria for identifying LV involvement was created. Depending on the combination of criteria for right and LV involvement, a diagnosis of classic (right dominant) ACM, biventricular ACM or left-dominant ACM is then made. The article reviews the rationale of the Padua criteria, summarizes the main modifications compared to the previous 2010 ITF criteria and provides three examples of the application of the Padua criteria in clinical practice.

395 Diagnostic role of native T1 mapping compared to conventional magnetic resonance techniques in cardiac diseases: a real-life study

Abstract Aims T1 mapping is a validated technique in cardiac magnetic resonance (CMR), however in real-life clinical practice its effectiveness to diagnose myocardial disease is still unclear. To compare native T1 mapping to conventional late gadolinium enhancement (LGE) and T2-STIR techniques for the evaluation of a cohort of consecutive patients undergoing CMR for the suspicion of myocardial disease. Methods and results CMR was performed in 323 patients, 206 males (64%), mean age 54 ± 8 years, and in 27 age- and sex-matched healthy controls. LGE, T2-STIR, and pre- and post-contrast T1 mapping were acquired as suggested by the SCMR position paper. The CMR findings of global and regional T1 mapping were compared to the respective results of LGE and T2-STIR techniques. The main baseline indications for CMR were: suspicion of ARVC in 20%; non-ischaemic DCM in 19%; HCM in 16%; chest pain without obstructive coronary artery in 14% of patients (suspicion of MINOCA, Tako-tsubo or myocarditis); other indications (amyloidosis, scleroderma, previous myocardial infarction, pericarditis, LV non-compaction) in the remaining of cases. At T2-STIR images myocardial hyperintensity suggesting oedema was found in 41 patients (27%). LGE images were positive in 206 patients (64%). Native T1 mapping was abnormal in 171 (49%). In 206 patients (64%) a matching between LGE and native T1 was found (both positive in 132 and negative in 74). T1 was also abnormal in 32 out of 41 (78%) with oedema at T2-STIR. Overall, LGE and/or T2-STIR were abnormal in 209 patients, whereas native T1 in 154(52%). Conventional techniques and T1 mapping were concordant in 208 patients (64%). Conventional techniques were abnormal in 76 (24%) of patients with negative T1 mapping. Finally, in 39 patients T1 mapping was positive despite negative conventional techniques (12%). Among these latter 39 patients, only in 18 T2-STIR were acquired based on clinical decision. Then, the percentage of cases where T1 mapping could have an additive role would range between 6% and 12%. T1 mapping was particularly able in conditions with diffuse myocardial damage as cardiac amyloidosis, scleroderma and fabry disease (additive role in 42%). On contrast, T1 mapping was less effective in cardiac disease with regional distribution of myocardial damage as myocardial infarction, HCM, myocarditis (additive role in 1%). Conclusions T1 mapping may give additive information in 6–12% of patient but is less effective cardiac disease presenting with regional or segmental distribution of myocardial damage. Results of the present study suggest that conventional LGE/T2-STIR and T1 mapping are complementary techniques and should be used together in every CMR examination.

Pressure-volume relationship by pharmacological stress cardiovascular magnetic resonance.

The variation between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an index of myocardial contractility, easily obtained during routine stress echocardiography and never tested during dipyridamole stress-cardiac magnetic resonance (CMR). We assessed the ΔESPVR index in patients with known/suspected coronary artery disease (CAD) who underwent dipyridamole stress-CMR. One-hundred consecutive patients (24 females, 63.76 ± 10.17years) were considered. ESPVR index was evaluated at rest and stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson's method. The ΔESPVR index showed a good inter-operator reproducibility. Mean ΔESPVR index was 0.48 ± 1.45mmHg/mL/m2. ΔESPVR index was significantly lower in males than in females. ΔESPVR index was not correlated to rest left ventricular end-diastolic volume index or ejection fraction. Forty-six of 85 patients had myocardial fibrosis detected by the late gadolinium enhancement technique and they showed significantly lower ΔESPVR values. An abnormal stress CMR was found in 25 patients and they showed significantly lower ΔESPVR values. During a mean follow-up of 56.34 ± 30.04months, 24 cardiovascular events occurred. At receiver-operating characteristic curve analysis, a ΔESPVR < 0.02mmHg/mL/m2 predicted the presence of future cardiac events with a sensitivity of 0.79 and a specificity of 0.68. The noninvasive assessment of the ΔESPVR index during a dipyridamole stress-CMR exam is feasible and reproducible. The ΔESPVR index was independent from rest LV dimensions and function and can be used for a comparative assessment of patients with different diseases. ΔESPVR indexby CMR can be a useful and simple marker for additional prognostic stratification.

Clinical impact of myocardial fibrosis in severe aortic stenosis.

The pressure overload due to the progressive narrowing of the valve area determines the development of the left ventricular hypertrophy which characterizes aortic stenosis (AS). The onset of myocardial fibrosis marks the inexorable decline of an initially compensatory response towards heart failure. However, myocardial fibrosis does not yet represent a key element in the prognostic and therapeutic framework of AS. In this context, cardiac magnetic resonance imaging plays a major role by highlighting both the focal irreversible fibrotic replacement, using the late gadolinium enhancement (LGE) technique, and the earlier diffuse reversible interstitial fibrosis, using the T1 mapping techniques. For this reason, the presence of myocardial fibrosis would be useful to identify a subgroup of patients at greater risk of events among the subjects with severe AS. Actually, more and more evidences seem to identify the presence of LGE as a powerful prognostic factor to be used to optimize the timing of prosthetic valve replacement. Randomized clinical trials, such as the EVoLVeD trial currently underway, will be needed to better define the importance of myocardial fibrosis assessment in the management of patients with AS.

Risk stratification in cardiomyopathies (dilated, hypertrophic, and arrhythmogenic cardiomyopathy) by cardiac magnetic resonance imaging.

Cardiac magnetic resonance imaging (CMR) is a non-invasive, multiplanar, and high spatial resolution imaging technique, which represents the current gold standard for the evaluation of biventricular volumes and function. Furthermore, unlike other methods, it has the great advantage of characterizing the myocardial tissue by identifying the presence of alterations, such as oedema and focal and diffuse fibrosis. In particular, the late gadolinium enhancement technique makes it possible to identify areas of focal fibrosis that often constitute the substrate for the triggering of threatening ventricular arrhythmias at the basis of sudden cardiac death. For this reason, the use of CMR in the study of cardiomyopathies has become of primary importance, both for the differential diagnosis and for patient risk stratification. In this brief review, the ability of CMR in prognostic stratification of patients with dilated, hypertrophic, and arrhythmogenic cardiomyopathy will be analysed. In particular, the role of CMR in the prediction of arrhythmic risk and in the decision-making process for the implantation of a cardiac defibrillator will be examined.

Changes in CMR parameters and prediction of cardiac complications in thalassemia major: fibrosis tells us more than iron

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The MIOT project received “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A. and ApoPharma Inc.). Background Cardiovascular magnetic Resonance (CMR) has dramatically changed the clinical practice and improved the prognosis in thalassemia major (TM). Aim This is the first study evaluating the predictive value of changes in CMR parameters (myocardial iron, function, and fibrosis) for cardiac complications in TM. Methods We followed prospectively 709 TM patients (374 females; 29.77 ± 8.53 years) consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) Network who performed a baseline and a 1st follow up CMR scan after 18 months. Myocardial iron overload (MIO) was measured by multislice multiecho T2* technique and atrial dimensions and biventricular function by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique. Risk classes were defined based on the 4 patterns of MIO from worst to normal. For patients with baseline MIO (at least one segmental T2*&amp;lt;20 ms), improvement was defined as a transition to a better risk class, stabilization as no change in risk class, and worsening as a transition to a worse risk class. For patients without baseline MIO, the worsening was the transition to a worse risk class. The percentage change was used for continuous variables. For biventricular ejection fractions, improvement was a %change &amp;gt; 10%, stabilization a %change between -10% and 10%, and worsening a %change&amp;lt;-10%. For biventricular volumes, LV mass index, and atrial areas, improvement was a % change&amp;lt;-10%, stabilization a % change between -10% and 10%, and worsening a % change &amp;gt; 10%. Myocardial fibrosis was considered absent if not detected in any of the two CMRs and present if detected in at least one examination. Results During a mean follow-up of 89.4 ± 33.3 months, cardiac events were recorded in 50 (7.1%) patients: 24 (48%) episodes of heart failure, 24 (48%) arrhythmias (23 supraventricular and 1 hypokinetic), and 2 (4.0%) pulmonary hypertension. Mean time from the 1st follow up CMR to the development of a cardiac complication was 75.31 ± 35.35 months. In the univariate Cox regression analysis, cardiac iron cleareance and myocardial fibrosis were identified as univariate prognosticators (Table 1). In the multivariate analysis only myocardial fibrosis remained an independent predictor factor. Conclusion The presence of myocardial fibrosis at the baseline CMR or developed within 18 months emerges as the strongest long-term predictor for cardiac complications in TM. Our data demonstrate the importance in using the contrast medium for CMR scans in thalassemia patients.

Multiparametric cardiac magnetic resonance assessmenti in sickle-beta-thalassemia

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The MIOT project receives “no-profit support” from industrial sponsorships (Chiesi Farmaceutici S.p.A., ApoPharma Inc.). Background. Sickle β-thalassemia (Sβ-thal) is a hereditary hemoglobinopathy resulting from the combined heterozygosity for sickle cell and β-thalassemia genes. Cardiac involvement in Sβ-thal patients has been poorly investigated. Aim. We aimed to evaluate myocardial iron overload and cardiac function by cardiovascular magnetic resonance (CMR) in patients with Sβ-thal. Methods. One hundred and eleven Sβ-thal patients consecutively enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) network were studied and compared with 46 sickle cell disease (SCD) patients. Biatrial and biventricular function CMR parameters of Sβ-thal patients were compared with those of 111 healthy volunteers, matched by gender and age. Myocardial iron overload (MIO) was assessed by T2* technique. Cine images were acquired to quantify biventricular function. Macroscopic myocardial fibrosis was evaluated by late gadolinium enhancement (LGE) technique. Results. In Sβ-thal and SCD patients morphological and functional MR parameters were not significantly different, except for left atrial area and SVI (p = 0.023 and p = 0.048, respectively) that were significantly higher in SCD patients. No significant differences between the two groups were found in terms of myocardial iron overload and macroscopic myocardial fibrosis. When compared to healthy subjects, Sβ-thal patients showed significantly higher bi-atrial and biventricular parameters except for LVEF that was significantly lower (Fig.1). Conclusions. The CMR analysis confirmed that Sβ-thal and SCD patients are phenotypically similar. Since Sβ-thal patients showed markedly different morphological and functional indices from healthy subjects, it would be useful to identify Sβ-thal/SCD-specific bi-atrial and biventricular reference values.

Detection of early phenotype cardiac sarcoidosis by cardiovascular magnetic resonance.

Cardiac sarcoidosis has high prevalence in sarcoidosis patients and contributes to significant morbidity and mortality. Early detection of cardiac sarcoidosis is essential to improving patients' symptoms and cardiovascular outcomes. Cardiovascular magnetic resonance imaging (CMR) is an excellent diagnostic modality for cardiac sarcoidosis. However, early phenotypes of cardiac sarcoidosis have more mild imaging phenotypes. These mild and sometimes subtle imaging phenotypes of cardiac sarcoidosis have lower diagnostic sensitivity and specificity for cardiac sarcoidosis by CMR when compared with more severe imaging phenotypes of cardiac sarcoidosis. In addition, many sarcoidosis patient cohorts frequently have heterogenous potential alternative etiologies for mild myocardial disease detected by mild late gadolinium enhancement (LGE) findings. In early phenotype cardiac sarcoidosis, analysis of the LGE pattern and location can improve the diagnostic specificity of these mild LGE findings. The current review focuses on the current strengths and challenges in CMR detection of early phenotypes of cardiac sarcoidosis by the LGE technique.

Evaluation of accelerated motion-compensated 3d water/fat late gadolinium enhanced MR for atrial wall imaging

Objective3D late gadolinium enhancement (LGE) imaging is a promising non-invasive technique for the assessment of atrial fibrosis. However, current techniques result in prolonged and unpredictable scan times and high rates of non-diagnostic images. The purpose of this study was to compare the performance of a recently proposed accelerated respiratory motion-compensated 3D water/fat LGE technique with conventional 3D LGE for atrial wall imaging.Materials and methods18 patients (age: 55.7±17.1 years) with atrial fibrillation underwent conventional diaphragmatic navigator gated inversion recovery (IR)-prepared 3D LGE (dNAV) and proposed image-navigator motion-corrected water/fat IR-prepared 3D LGE (iNAV) imaging. Images were assessed for image quality and presence of fibrosis by three expert observers. The scan time for both techniques was recorded.ResultsImage quality scores were improved with the proposed compared to the conventional method (iNAV: 3.1 ± 1.0 vs. dNAV: 2.6 ± 1.0, p = 0.0012, with 1: Non-diagnostic to 4: Full diagnostic). Furthermore, scan time for the proposed method was significantly shorter with a 59% reduction is scan time (4.5 ± 1.2 min vs. 10.9 ± 3.9 min, p < 0.0001). The images acquired with the proposed method were deemed as inconclusive less frequently than the conventional images (expert 1/expert 2: 4/7 dNAV and 2/4 iNAV images inconclusive).DiscussionThe motion-compensated water/fat LGE method enables atrial wall imaging with diagnostic quality comparable to the current conventional approach with a significantly shorter scan of about 5 min.

Whole-Heart High-Resolution Late Gadolinium Enhancement: Techniques and Clinical Applications.

In cardiovascular magnetic resonance, late gadolinium enhancement (LGE) has become the cornerstone of myocardial tissue characterization. It is widely used in clinical routine to diagnose and characterize the myocardial tissue in a wide range of ischemic and nonischemic cardiomyopathies. The recent growing interest in imaging left atrial fibrosis has led to the development of novel whole‐heart high‐resolution late gadolinium enhancement (HR‐LGE) techniques. Indeed, conventional LGE is acquired in multiple breath‐holds with limited spatial resolution: ~1.4–1.8 mm in plane and 6–8 mm slice thickness, according to the Society for Cardiovascular Magnetic Resonance standardized guidelines. Such large voxel size prevents its use in thin structures such as the atrial or right ventricular walls. Whole‐heart 3D HR‐LGE images are acquired in free breathing to increase the spatial resolution (up to 1.3 × 1.3 × 1.3 mm3) and offer a better detection and depiction of focal atrial fibrosis. The downside of this increased resolution is the extended scan time of around 10 min, which hampers the spread of HR‐LGE in clinical practice. Initially introduced for atrial fibrosis imaging, HR‐LGE interest has evolved to be a tool to detect small scars in the ventricles and guide ablation procedures. Indeed, the detection of scars, nonvisible with conventional LGE, can be crucial in the diagnosis of myocardial infarction with nonobstructed coronary arteries, in the detection of the arrhythmogenic substrate triggering ventricular arrhythmia, and improve the confidence of clinicians in the challenging diagnoses such as the arrhythmogenic right ventricular cardiomyopathy. HR‐LGE also offers a precise visualization of left ventricular scar morphology that is particularly useful in planning ablation procedures and guiding them through the fusion of HR‐LGE images with electroanatomical mapping systems. In this narrative review, we attempt to summarize the technical particularities of whole‐heart HR‐LGE acquisition and provide an overview of its clinical applications with a particular focus on the ventricles.Evidence Level2Technical Efficacy Stage2

Three-dimensional late gadolinium enhancement increases the diagnostic yield of cardiovascular magnetic resonance to detect low voltage in the right ventricular outflow tract

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) using late gadolinium enhancement (LGE) fails to detect scar tissue in patients with electroanatomical abnormalities and biopsy-proven structural heart disease. It has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT). Three- dimensional (3D) LGE enables high-spatial resolution more appropriate to the thin-walled right ventricle than two-dimensional (2D) LGE. Objective Our aim was to evaluate if the use of 3D-LGE would improve the performance of CMR to detect low voltage areas in the RVOT of patients with PVCs. Methods Since May 2020 we performed 3D-LGE CMR in 11 consecutive patients that underwent ablation of frequent PVCs. A control group of 11 consecutive patients that underwent catheter ablation by the same operator and had a 2D-LGE CMR performed before ablation was also studied. All patients had normal 2D-LGE CMR. A 3D electroanatomical bipolar voltage map of the RVOT was performed in sinus rhythm (0.5 mV-1.5 mV colour display). Areas with electrograms &amp;lt;1.5 mV represented the LVA. The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated. We compared the accuracy of CMR for detecting LVA in the two groups: 3D LGE and 2D LGE. Results The median number of points used for the voltage map was 344 (242-450). 18 patients (82%) displayed LVAs. The site of origin of the PVCs was the RVOT in 17 patients and the left ventricular outflow tract (LVOT) in 5. Comparison between groups is displayed in the table. 2D LGE CMR failed to demonstrate abnormalities of the RVOT in any of the patients that presented with LVAs. 3D CMR showed presence of fibrosis (Figure) in 3 out of 9 patients with LVAs (33%). Conclusion CMR using 3-D LGE techniques showed an increased power to diagnose structural abnormalities. This technique may be a better choice in initial stages of RVOT disease. All sampleN = 223D-LGE CMRN = 112D-LGE CMRN = 11p-valueAge in years, median (Q1-Q3)47 (35-68)62 (34-55)42 (34-55)0.243Male gender, n (%)8 (36)3 (27)5 (46)0.330PVCs RVOT/LVOT17/59/28/30.500Nº points in the map, median (Q1-Q3)344 (242-450)350 (259-450)300 (158-345)0.076Low voltage areas, n (%)18 (82)9 (82)9 (82)0.707Abstract Figure.

Left Ventricular Thrombi: Insights from Cardiac Magnetic Resonance Imaging.

Objective: Cardiovascular magnetic resonance imaging (CMR) late gadolinium enhancement technique (LGE) detects thrombus rather than anatomical presence based on tissue properties and is theoretically highly accurate. The present study’s goal was to compare the diagnostic accuracy obtained with various CMR techniques and transthoracic echocardiography to diagnose left ventricular thrombus and evaluate the prevalence and perspectives of left ventricular (LV) thrombus among patients with impaired systolic left ventricular function. Methods: In a single academic referral center, a retrospective database review of all CMR assessments of the established left ventricular thrombus was carried out in 206 consecutive patients with reduced systolic function for five years. To assess thrombus risk factors, clinical and imaging parameters were analyzed. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), echocardiography, and cine-CMR sequence accuracy have been identified. LV structural parameters were quantified to detect markers for thrombus and predictors of the additive usefulness of contrast-enhanced thrombus imaging. Comparisons against LGE-CMR were made, which was used as the standard. Results: A 7.8 percent prevalence of left ventricular thrombus was identified by LGE-CMR. Cine-CMR increased the diagnostic efficiency for echocardiographic thrombus identification in this group, with sensitivity increasing from 50 percent by echocardiography to 75 percent by cine-CMR (p = 0.008). Dark blood CMR (DB-CMR) has better sensitivity and accuracy than echocardiography (p < 0.001), comparable to cine-CMR. The transmural infarct size was an independent marker for thrombus after correction for the LVEF and LV volume while considering only CMR parameters. There were significantly higher embolic events (HR = 71.33; CI 8.31–616.06, p < 0.0001) in LV thrombus patients detected by LGE-CMR. Conclusion: CMR imaging was more sensitive to left ventricular thrombi identification compared with transthoracic echocardiography. An additional parameter available from LGE-CMR and shown as an independent risk factor for left ventricular thrombus is the myocardial scar.

Prospective cardiac magnetic resonance imaging survey in myelodysplastic syndrome patients: insights from an Italian network.

We prospectively evaluated changes in cardiac and hepatic iron overload (IO) and in morpho-functional cardiac parameters and myocardial fibrosis by magnetic resonance imaging (MRI) in patients with low-risk and intermediate-1-risk myelodysplastic syndromes (MDS). Fifty patients enrolled in the Myocardial Iron Overload in MyElodysplastic Diseases (MIOMED) study were followed for 12 months. IO was quantified by the T2* technique and biventricular function parameters by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique. Twenty-eight patients (71.89±8.46 years; 8 females) performed baseline and follow-up MRIs. Thirteen patients had baseline hepatic IO, with a higher frequency among transfusion-dependent patients. Out of the 15 patients with a baseline MRI liver iron concentration <3 mg/g/dw, two (non-chelated) developed hepatic IO. Thirteen (46.4%) patients had an abnormal T2* value in at least one myocardial segment. One patient without hepatic IO and non-transfused had baseline global T2* <20 ms. Among the 15 patients with no baseline myocardial IO (MIO), 2 worsened. There was a significant increase in both left and right ventricular end-diastolic volume indexes. Thirty-six percent of patients showed myocardial fibrosis correlating with aging. Two new occurrences were detected at the follow-up. In conclusion, by a more sensitive segmental approach, MIO is quite frequent in MDS patients and it can be present also in non-transfused patients and in absence of detectable hepatic iron. The incidence of cardiac and hepatic IO and of myocardial fibrosis and the increase in biventricular volumes after a 12-month interval suggest performing periodic MRI scans to better manage MDS patients.

Role of free-breathing motion-corrected late gadolinium enhancement technique for image quality assessment and LGE quantification

ObjectiveTo compare the image quality and late gadolinium enhancement (LGE) quantification between free-breathing motion-corrected and conventional breath-hold LGE method in a variety of cardiovascular diseases. Materials and Methods149 consecutive patients underwent contrast-enhanced cardiac magnetic resonance examination employing both free-breathing motion-corrected LGE and conventional breath-hold LGE method. Scan time, contrast-to-noise ratio, overall image quality score and LGE mass were measured and analyzed statistically. ResultsFree-breathing motion-corrected LGE method had a shorter scan time and higher overall image quality score in comparison with conventional breath-hold LGE method (p < 0.001). Univariate/multivariate logistic regression analysis showed that breath-holding difficulty, high heart rate and arrhythmia could be predictive factors possibly for an inferior image quality score (p < 0.05 for all). The contrast-to-noise ratios of free-breathing motion-corrected LGE images were higher than those of conventional breath-hold LGE images (p < 0.001). In the cases with subepicardial and/or transmural myocardial enhancement, the measured LGE masses were larger on free-breathing motion-corrected LGE images in comparison with those on conventional breath-hold LGE images (p < 0.05). ConclusionFree-breathing motion-corrected LGE could be a better choice for patients who need contrast-enhanced cardiac MRI and have one or more of the risk factors for an inferior image quality score, including breath-holding difficulty, high heart rate and arrhythmia. However, an overestimation of LGE mass on free-breathing motion-corrected LGE image should be taken into consideration when LGE pattern involves subepicardial and/or transmural myocardium.