Dynamic late gadolinium enhancement simply quantified using myocardium to lumen signal ratio: normal range of ratio and diffuse abnormal enhancement of cardiac amyloidosis

Purpose:

To detect abnormal myocardial tissue in patients with diffuse myocardial disease, we propose a simple technique of late gadolinium enhancement (LGE) using routine myocardial imaging modalities.

Materials and Methods:

We retrospectively reviewed LGE images from 51 patients with normal myocardium and 10 patients with pathologically proven cardiac amyloidosis (CA). We obtained sequential LGE images from patients at 2, 5, 10, and 20 minutes after injection of Gd‐DTPA (0.15 mmol/kg) with a fixed inversion time of 300 msec. We evaluated the signal intensity ratio of the myocardium to the left ventricular lumen (M/L) in one long and two short axial sections within 463 and 120 segments of normal myocardium and CA, respectively. Visually unenhanced and enhanced regions of myocardium were evaluated in each segment of patients with CA.

Results:

Among normal myocardium, M/L (means ± standard deviation; SD) was stable with time (2, 5, 10, and 20 min: 0.34 ± 0.03, 0.31 ± 0.05, 0.34 ± 0.07, and 0.42 ± 0.11, respectively). The calculated M/L of unenhanced (0.60 ± 0.20, 0.68 ± 0.19, 0.76 ± 0.20, and 1.09 ± 0.25, respectively) and enhanced myocardium (0.77 ± 0.27, 0.99 ± 0.29, 1.20 ± 0.40, and 1.45 ± 0.54, respectively) in patients with CA was significantly greater than that seen for the normal myocardium at each time and increased over time.

Conclusion:

In patients with CA, diffuse myocardial abnormalities can be demonstrated using M/L, and this technique may be useful for the characterization of other myocardial diseases. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.     

Feasibility of FDG-PET in myocarditis: Comparison to CMR using integrated PET/MRI

Objective

Besides cardiac sarcoidosis, FDG-PET is rarely used in the diagnosis of myocardial inflammation, while cardiac MRI (CMR) is the actual imaging reference for the workup of myocarditis. Using integrated PET/MRI in patients with suspected myocarditis, we prospectively compared FDG-PET to CMR and the feasibility of integrated FDG-PET/MRI in myocarditis.

Methods

A total of 65 consecutive patients with suspected myocarditis were prospectively assessed using integrated cardiac FDG-PET/MRI. Studies comprised T2-weighted imaging, late gadolinium enhancement (LGE), and simultaneous PET acquisition. Physiological glucose uptake in the myocardium was suppressed using dietary preparation.

Results

FDG-PET/MRI was successful in 55 of 65 enrolled patients: two patients were excluded due to claustrophobia and eight patients due to failed inhibition of myocardial glucose uptake. Compared with CMR (LGE and/or T2), sensitivity and specificity of PET was 74% and 97%. Overall spatial agreement between PET and CMR was κ = 0.73. Spatial agreement between PET and T2 (κ = 0.75) was higher than agreement between PET and LGE (κ = 0.64) as well as between LGE and T2 (κ = 0.56).

Conclusion

In patients with suspected myocarditis, FDG-PET is in good agreement with CMR findings.

     

Is myocardial stress perfusion MR-imaging suitable to predict the long term clinical outcome after revascularization?

Introduction

Aim of our study was to evaluate, whether myocardial ischemia or myocardial infarction (MI) depicted by myocardial stress perfusion MR imaging (SP CMR) can predict the clinical outcome in patients with coronary artery disease (CAD).

Materials and method

220 patients were included. Myocardial perfusion was assessed at stress and at rest, using a 2D saturation recovery gradient echo sequence (SR GRE) and myocardial viability by late gadolinium enhancement magnetic resonance images (LGE CMR). MR-images were assessed in regard of presence and extent of MI and ischemia. Patients were monitored for major adverse cardiac events (MACE) (monitoring period: 5–7 years). MACE were correlated with the initial results of SP CMR.

Results

Ischemia was found in 143 patients, MI in 107 patients. Number of MACE was in patients with normal SP CMR 0 (51 patients), with ischemia 21 (62 patients), with MI 14 (26 patients), with ischemia and MI 52 (81 patients). In all patients with severe MACE (MI, death) and in 63 of those with recurring symptoms LGE CMR revealed MI at baseline.

Conclusion

Negative SP CMR indicates low risk for MACE. In patients with stress induced ischemia, MACE might occur even after myocardial revascularization. The presence of MI proved by LGE CMR is associated with a significantly increased risk for MACE.     

MRT bei kardialer Sarkoidose und Amyloidose

Clinical/methodical issue

Sarcoidosis and amyloidosis are both multisystem disorders, which may involve the heart; however, isolated cardiac disease is rare. Diagnosis of cardiac sarcoidosis and amyloidosis is crucial because the patient prognosis is dependent on cardiac involvement and early treatment.

Standard radiological methods

Echocardiography is the first line imaging modality in the diagnostic work-up of both diseases, possibly giving hints towards the correct diagnosis. Besides myocardial biopsy and radionuclide studies cardiac magnetic resonance imaging (MRI) is routinely performed in patients suspect of having infiltrative cardiomyopathy.

Methodical innovations

The T1 mapping procedure is currently being evaluated as a new technique for detection and quantification of global myocardial enhancement, as seen in cardiac amyloidosis.

Performance

Sensitivities and specificities for detection of cardiac sarcoidosis and amyloidosis can be significantly improved by MRI, especially with late gadolinium enhancement (LGE) imaging. In cardiac sarcoidosis the use of LGE is outcome-related while in amyloidosis analysis of T1-mapping may be of prognostic value.

Practical recommendations

If cardiac involvement in sarcoidosis or amyloidosis is suspected cardiac MRI including LGE should be performed for establishing the diagnosis.     

Detection of long-term progression of myocardial fibrosis in Duchenne muscular dystrophy in an affected family: A cardiovascular magnetic resonance study

Background

Detection of myocardial fibrosis and left ventricular dysfunction in Duchenne muscular dystrophy (DMD) is the corner stone for further therapeutic studies. Little is known about the ability of cardiac magnetic resonance imaging (CMR) to evaluate progression of myocardial fibrosis. Aim of our study was to provide CMR data in a previously genotyped DMD family and to evaluate whether progression of myocardial fibrosis could be visualized.

Methods and results

DMD genotypes were available in 14 family members. CMR was performed in 4/5 carrier females, in 2/2 affected males and in one healthy family member with normal genotype. Functional images and late gadolinium enhanced (LGE) images in contiguous short-axis orientation were acquired at baseline and follow-up of 1231 days CMR examination could be repeated in three carrier females, in one affected male and in the healthy subject previously scanned. Mean decrease of left ventricular ejection fraction during the follow-up period was 10.5 ± 11.0%, mean progression of LGE volume 11.7 ± 9.5%.

Conclusions

Myocardial fibrosis seems to occur prior to global left ventricular dysfunction in DMD diseased males and carrier females. CMR could be used to evaluate progression of myocardial fibrosis and left ventricular function and may thus serve as an important diagnostic tool in the evaluation of therapeutical options in DMD.     

Shorter difference between myocardium and blood optimal inversion time suggests diffuse fibrosis in dilated cardiomyopathy

Purpose:

To find evidence of diffuse fibrosis in dilated cardiomyopathy (DCM) patients by comparing measurements on clinical late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) studies between DCM and healthy subjects.

Materials and Methods:

LGE‐CMR and the Look–Locker images from 20 DCM patients and 17 healthy controls were analyzed. Blood signal‐to‐noise ratio (SNR), myocardium SNR, and blood‐to‐myocardium contrast‐to‐noise ratio (CNR) were measured on the LGE‐CMR images. The optimal inversion time (TI) to null blood and myocardium was determined on the Look–Locker images. The postcontrast T₁ was estimated using a phantom study that correlated optimal TI and heart rate to T₁.

Results:

The blood SNR was lower, myocardium SNR was higher, and the blood‐to‐myocardium CNR was lower (6.6 ± 0.7 vs. 10.3 ± 0.9, P = 0.004) on DCM LGE‐CMR images as compared to controls. The blood‐myocardium optimal TI difference (ΔTI) was lower (38 ± 2 msec vs. 55 ± 3 msec, P < 0.001) in DCM, and the estimated blood‐myocardium T₁ difference (ΔT₁) (116 ± 6 msec vs. 152 ± 8 msec, P = 0.001) was also lower.

Conclusion:

DCM patients have reduced blood‐myocardium ΔTI and ΔT₁, and lower CNR as compared to controls, suggesting the presence of diffuse fibrosis. This may impact the interpretation of LGE data. J. Magn. Reson. Imaging 2009;30:967–972. © 2009 Wiley‐Liss, Inc.     

The cardiac magnetic resonance (CMR) approach to assessing myocardial viability

Cardiac magnetic resonance (CMR) is a noninvasive imaging method that can determine myocardial anatomy, function, perfusion, and viability in a relative short examination. In terms of viability assessment, CMR can determine viability in a non-contrast enhanced scan using dobutamine stress following protocols comparable to those developed for dobutamine echocardiography. CMR can also determine viability with late gadolinium enhancement (LGE) methods. The gadolinium-based contrast agents used for LGE differentiate viable myocardium from scar on the basis of differences in cell membrane integrity for acute myocardial infarction. In chronic myocardial infarction, the scarred tissue enhances much more than normal myocardium due to increases in extracellular volume. LGE is well validated in pre-clinical and clinical studies that now span from almost a cellular level in animals to human validations in a large international multicenter clinical trial. Beyond infarct size or infarct detection, LGE is a strong predictor of mortality and adverse cardiac events. CMR can also image microvascular obstruction and intracardiac thrombus. When combined with a measure of area at risk like T2-weighted images, CMR can determine infarct size, area at risk, and thus estimate myocardial salvage 1-7 days after acute myocardial infarction. Thus, CMR is a well validated technique that can assess viability by gadolinium-free dobutamine stress testing or late gadolinium enhancement.     

Early molecular imaging of interstitial changes in patients after myocardial infarction: Comparison with delayed contrast-enhanced magnetic resonance imaging

Introduction

The clinical feasibility of noninvasive imaging of interstitial alterations after myocardial infarction (MI) was assessed using a technetium-99m-labeled RGD imaging peptide (RIP). In experimental studies, RIP has been shown to target integrins associated with collagen-producing myofibroblasts (MFB).

Methods and Results

Ten patients underwent myocardial perfusion imaging (MPI) within the first week after MI. At 3 and 8 weeks after MI, RIP was administered intravenously and SPECT images acquired for interstitial imaging. RIP imaging was compared to initial MPI and to the extent of scar formation defined by late gadolinium-enhanced (LGE) cardiac magnetic resonance (CMR) imaging 1 year after MI. RIP uptake was observed in 7 of the 10 patients at both 3 and 8 weeks. Although, RIP uptake corresponded to areas of perfusion defects, it usually extended beyond the infarct zone to a variable extent; 2 of 7 patients showed tracer uptake throughout myocardium. In all positive cases, RIP uptake was similar to the extent of scar observed at 1 year by LGE-CMR imaging.

Conclusion

This study demonstrates that RGD-based imaging early after MI may predict the eventual extent of scar formation, which often exceeds initial MPI deficit but colocalizes with LGE in CMR imaging performed subsequently.     

T2-weighted cardiac MR assessment of the myocardial area-at-risk and salvage area in acute reperfused myocardial infarction: comparison of state-of-the-art dark blood and bright blood T2-weighted sequences

Purpose:

To compare different state‐of‐the‐art T2‐weighted (T2w) imaging sequences combined with late gadolinium enhancement (LGE) for myocardial salvage area (MSA) assessment by cardiac magnetic resonance (CMR). T2w imaging has been used to assess the myocardial area at risk (AAR) in acute myocardial infarction (AMI) patients, but its clinical application is challenging due to technical and physical limitations.

Materials and Methods:

Thirty patients with reperfused AMI underwent complete CMR imaging 2–5 days after hospital admission. Myocardial AAR and MSA were quantified on four different T2w sequences: (a) free‐breathing T2‐prepared single‐shot balanced steady‐state free precession (T2p_ssbSSFP); (b) breathhold T2‐weighted acquisition for cardiac unified T2 edema (ACUTE); (c) breathhold T2w dark‐blood inversion recovery turbo‐spin echo (IR‐TSE) (short‐term inversion recovery: STIR); and (d) free‐breathing high‐resolution T2 dark‐blood navigated BLADE. The diagnostic performance of each technique was also assessed.

Results:

Quantitative analysis showed significant differences in myocardial AAR extent as quantified by the four T2w sequences (P < 0.05). There were also significant differences in sensitivity, specificity and overall diagnostic performance.

Conclusion:

Detection and quantification of AAR, and thus of MSA, by T2wCMR in reperfused AMI patients varied significantly between different T2w sequences in the same clinical setting. J. Magn. Reson. Imaging 2012;328‐339. © 2011 Wiley Periodicals, Inc.     

Reproducibility of first‐pass cardiovascular magnetic resonance myocardial perfusion

Purpose:

To assess the reproducibility of semiquantitative and quantitative analysis of first‐pass myocardial perfusion cardiovascular magnetic resonance (CMR) in healthy volunteers.

Materials and Methods:

Eleven volunteers underwent myocardial perfusion CMR during adenosine stress and rest on 2 separate days. Perfusion data were acquired in a single mid‐ventricular section in two cardiac phases to permit cardiac phase reproducibility comparisons. Semiquantitative analysis was performed to derive normalized upslopes of myocardial signal intensity profiles (myocardial perfusion index, MPI). The quantitative analysis estimated absolute myocardial blood flow (MBF) using Fermi‐constrained deconvolution. The perfusion reserve index was calculated by dividing stress by rest data. Two observers performed all the measurements independently. One observer repeated all first scan measurements 4 weeks later.

Results:

The reproducibility of perfusion CMR was highest for semiquantitative analysis with an intraobserver coefficient of variability (CoV) of 3%–7% and interobserver CoV of 4%–10%. Semiquantitative interstudy comparison was less reproducible (CoV of 13%–27%). Quantitative intraobserver CoV of 10%–18%, interobserver CoV of 8%–15% and interstudy CoV of 20%–41%. Reproducibility of systolic and diastolic phases and the endocardial and epicardial myocardial layer showed similar reproducibility on both semiquantitative and quantitative analysis.

Conclusion:

The reproducibility of CMR myocardial perfusion estimates is good, but varies between intraobserver, interobserver, and interstudy comparisons. In this study semiquantitative analysis was more reproducible than quantitative analysis. J. Magn. Reson. Imaging 2013;37:865–874. © 2013 Wiley Periodicals, Inc.     

磁共振心功能电影序列快速多参数对比评估危重症STEMI患者的扫描技术探索

目的 阐述磁共振心功能电影序列(CINE)在危重症急性ST段抬高型心肌梗死(STEMI)患者扫描及后处理对比分析中的应用价值.方法 选取临床确诊的危重症STEMI患者1例,通过心脏磁共振成像(CMR)序列的快速优化组合,重点对比分析心功能成像序列,分享扫描经验和技术要点.结果 CMR全部检查时间仅为18 min,CIN...     

MR relaxometry and perfusion of the myocardium in spontaneously hypertensive rat: correlation with histopathology and effect of anti-hypertensive therapy

Objectives

To investigate myocardial relaxation times and perfusion values in spontaneously hypertensive rats (SHRs) at various stages of the disease, with or without anti-fibrotic therapy, and to correlate magnetic resonance imaging (MRI) findings with histopathological myocardial fibrosis and capillary density.

Methods

Five groups of rats underwent MRI at 4.7 T. They were either untreated or treated with an aldosterone-synthase inhibitor. T1, T2 and T2* relaxation times were determined and myocardial perfusion was quantified from an arterial spin labelling sequence. MR relaxation times and perfusion values were compared with the fibrotic content and capillary density of the myocardium obtained at histology after euthanasia.

Results

T1 values significantly increased during the course of hypertensive disease, and correlated with myocardial fibrosis (R?=?0.71, P?<?0.001); T2 values also increased but were weakly correlated with myocardial fibrosis (R?=?0.27,P?=?0.047). Myocardial perfusion and capillary density significantly decreased with hypertensive disease but they did not correlate. Following prolonged treatment, we observed a trend associating T1 decrease and improved perfusion compared with untreated SHRs.

Conclusions

Myocardial T1 and T2 values increase with hypertensive disease, whereas myocardial perfusion decreases. The correlation between T1 values and collagen density suggests that the former could be considered as a non-invasive marker of myocardial fibrosis.

Key Points

? MR is increasingly used to assess alteration in myocardial tissue content. ? MR relaxometry and perfusion can be assessed in rats without exogenous contrast agents. ? Myocardial T1 and T2 values significantly increase during the course of hypertensive heart disease. ? T1 values correlate significantly with myocardial collagen content. ? Myocardial perfusion values decrease with hypertensive disease.     

Imaging cardiac amyloidosis: a pilot study using 18F-florbetapir positron emission tomography

Purpose

Cardiac amyloidosis, a restrictive heart disease with high mortality and morbidity, is underdiagnosed due to limited targeted diagnostic imaging. The primary aim of this study was to evaluate the utility of ¹⁸F-florbetapir for imaging cardiac amyloidosis.

Methods

We performed a pilot study of cardiac ¹⁸F-florbetapir PET in 14 subjects: 5 control subjects without amyloidosis and 9 subjects with documented cardiac amyloidosis. Standardized uptake values (SUV) of ¹⁸F-florbetapir in the left ventricular (LV) myocardium, blood pool, liver, and vertebral bone were determined. A ¹⁸F-florbetapir retention index (RI) was computed. Mean LV myocardial SUVs, target-to-background ratio (TBR, myocardial/blood pool SUV ratio) and myocardial-to-liver SUV ratio between 0 and 30 min were calculated.

Results

Left and right ventricular myocardial uptake of ¹⁸F-florbetapir were noted in all the amyloid subjects and in none of the control subjects. The RI, TBR, LV myocardial SUV and LV myocardial to liver SUV ratio were all significantly higher in the amyloidosis subjects than in the control subjects (RI median 0.043 min^?1, IQR 0.034 – 0.051 min^?1, vs. 0.023 min^?1, IQR 0.015 – 0.025 min^?1, P?=?0.002; TBR 1.84, 1.64 – 2.50, vs. 1.26, IQR 0.91 – 1.36, P?=?0.001; LV myocardial SUV 3.84, IQR 1.87 – 5.65, vs. 1.35, IQR 1.17 – 2.28, P?=?0.029; ratio of LV myocardial to liver SUV 0.67, IQR 0.44 – 1.64, vs. 0.18, IQR 0.15 – 0.35, P?=?0.004). The myocardial RI, TBR and myocardial to liver SUV ratio also distinguished the control subjects from subjects with transthyretin and those with light chain amyloid.

Conclusion

¹⁸F-Florbetapir PET may be a promising technique to image light chain and transthyretin cardiac amyloidosis. Its role in diagnosing amyloid in other organ systems and in assessing response to therapy needs to be further studied.     

Differentiation of myocardial ischemia and infarction assessed by dynamic computed tomography perfusion imaging and comparison with cardiac magnetic resonance and single-photon emission computed tomography

Objectives

To evaluate the feasibility of myocardial blood flow (MBF) by computed tomography from dynamic CT perfusion (CTP) for detecting myocardial ischemia and infarction assessed by cardiac magnetic resonance (CMR) or single-photon emission computed tomography (SPECT).

Methods

Fifty-three patients who underwent stress dynamic CTP and either SPECT (n?=?25) or CMR (n?=?28) were retrospectively selected. Normal and abnormal perfused myocardium (ischemia/infarction) were assessed by SPECT/CMR using 16-segment model. Sensitivity and specificity of CT-MBF (mL/g/min) for detecting the ischemic/infarction and severe infarction were assessed.

Results

The abnormal perfused myocardium and severe infarction were seen in SPECT (n?=?90 and n?=?19 of 400 segments) and CMR (n?=?223 and n?=?36 of 448 segments). For detecting the abnormal perfused myocardium, sensitivity and specificity were 80 % (95 %CI, 71-90) and 86 % (95 %CI, 76-91) in SPECT (cut-off MBF, 1.23), and 82 % (95 %CI, 76-88) and 87 % (95 %CI, 80-92) in CMR (cut-off MBF, 1.25). For detecting severe infarction, sensitivity and specificity were 95 % (95 %CI, 52-100) and 72 % (95 %CI, 53-91) in SPECT (cut-off MBF, 0.92), and 78 % (95 %CI, 67-97) and 80 % (95 %CI, 58-86) in CMR (cut-off MBF, 0.98), respectively.

Conclusions

Dynamic CTP has a potential to detect abnormal perfused myocardium and severe infarction assessed by SPECT/CMR using comparable cut-off MBF.

Key Points

? CT-MBF accurately reflects the severity of myocardial perfusion abnormality. ? CT-MBF provides good diagnostic accuracy for detecting myocardial perfusion abnormalities. ? CT-MBF may assist in stratifying severe myocardial infarction in abnormal perfusion myocardium.

     

Regional myocardial damage and active inflammation in patients with cardiac sarcoidosis detected by non-invasive multi-modal imaging

Aims

Cardiac sarcoidosis (CS) can be diagnosed using ¹⁸F-FDG-PET/CT (PET), cardiovascular magnetic resonance (CMR), and ¹²³I-BMIPP/²⁰¹TlCl dual myocardial SPECT. This study aims to clarify the relationships among the three modalities with respect to CS.

Methods and results

We evaluated 16 patients (male n = 11; age 55 ± 13 years) with confirmed CS who underwent PET, CMR, and dual SPECT with gated SPECT before starting steroid therapy. The left ventricular myocardium was divided into 17 segments to obtain SUVmax for PET images, defect scores from 0 to 4 (0 normal; 4 absent), and mismatch scores for dual SPECT (BMDS, TLDS, and MS) images and late gadolinium enhancement (LGE) scores (0 none; 1 partly positive; 2 homogeneous) on CMR images. Summed BMDS, TLDS, and MS were 18.6 ± 12.6, 12.9 ± 10.9, and 5.7 ± 3.1, respectively. The segmental BMDS and TLDS scores became significantly higher as the LGE scores increased. The MS scores were significantly higher in areas of LGE with a score of 1 than 0 (both, p < 0.001), but did not significantly differ between areas with LGE scores of 1 and 2. The SUVmax was significantly higher in LGE areas with a score of 1 than 0 (p < 0.025), but did not significantly differ between those with scores of 1 or 2.

Conclusion

Regions with a higher SUVmax indicating active myocardial inflammation were mainly located in areas with LGE, where BMIPP and TL mismatches were evident in patients with CS.

     

Evaluation of Myocardial Strain in Patients With Amyloidosis Using Cardiac Magnetic Resonance Feature Tracking

Purpose

To study the use of cardiac magnetic resonance (CMR) feature tracking technique in evaluation of myocardial amyloidosis.

Late gadolinium enhancement on cardiac magnetic resonance imaging: is it associated with a higher incidence of nonsustained ventricular tachycardia in patients with idiopathic dilated cardiomyopathy?

Purpose  

Late gadolinium enhancement (LGE) during cardiac magnetic resonance imaging (MRI) can be seen in patients with myocardial fibrosis accompanied by myocardial infarction and cardiomyopathy. Some idiopathic dilated cardiomyopathy (DCM) patients have fibrosis in the myocardium and show LGE during cardiac MRI. The purpose of this study was to investigate the clinical significance of LGE in patients with DCM.     

Left ventricular diastolic function in type 2 diabetes mellitus is associated with myocardial triglyceride content but not with impaired myocardial perfusion reserve

Purpose:

To study myocardial perfusion reserve and myocellular metabolic alterations indicated by triglyceride content as possible causes of diastolic dysfunction in patients with type 2 diabetes mellitus, preserved systolic function, and without clinically evident coronary artery disease.

Materials and Methods:

Patients with type 2 diabetes mellitus (n = 42) underwent cardiac magnetic resonance (CMR) for quantification of 1) myocardial contractility by strain‐encoded MR (SENC); 2) myocardial triglyceride content by proton magnetic resonance spectroscopy (¹H‐MRS); and 3) myocardial perfusion reserve during pharmacologic hyperemia. Age‐matched healthy volunteers (n = 16) also underwent CMR to acquire normal values for myocardial strain and perfusion reserve.

Results:

Stress CMR procedures were successfully performed in all subjects, and no regional inducible perfusion defects were observed in type 2 diabetes mellitus patients. Diastolic strain rate and myocardial perfusion reserve were significantly impaired in patients with type 2 diabetes mellitus compared to control subjects (P < 0.001 for both). Interestingly, impaired diastolic function in type 2 diabetes mellitus was not associated with impaired myocardial perfusion reserve (r = 0.12, P = NS). Conversely a significant association was observed between diastolic dysfunction and myocardial triglyceride content (r = ?0.71, P < 0.001), which proved to be independent of age, gender, diabetes duration, blood pressure, and fasting blood glucose.

Conclusion:

Myocardial steatosis may represent an early marker of diabetic heart disease, triggering subclinical myocardial dysfunction irrespective of myocardial perfusion reserve. J. Magn. Reson. Imaging 2012;35:804–811. © 2011 Wiley Periodicals, Inc.

     

Contrast‐enhanced myocardial T1‐weighted scout (Look–Locker) imaging for the detection of myocardial damages in hypertrophic cardiomyopathy

Purpose

To assess the myocardial damage in hypertrophic cardiomyopathy (HCM) using contrast‐enhanced myocardial T1‐weighted scout (Look–Locker) magnetic resonance imaging (MRI).

Materials and Methods

Twenty‐three patients with HCM and seven comparative patients without known HCM serving as controls underwent cine, contrast‐enhanced myocardial T1‐weighted scout and delayed‐enhancement MRI using a 1.5T unit. Intervals of null points between myocardium and blood were compared among hyperenhancing and nullified myocardium of HCM and the normal myocardium. The relationship between these myocardial patterns and global cardiac functions was analyzed in HCM.

Results

The hyperenhancing myocardium, dense myocardial fibrosis in HCM had null points significantly shorter than blood, normal myocardium, and nullified myocardium of HCM (P < 0.0001). The number of hyperenhancing myocardial segments correlated with the ejection fraction (P = 0.045). The nullified myocardium of HCM showed shorter intervals of the null points between myocardium and blood than did the normal myocardium, indicating the dispersed myocardial fibrosis (P = 0.0032). The interval of null points between the nullified myocardium and blood showed a significant correlation with the increase in myocardial mass in HCM (P = 0.034).

Conclusion

Contrast‐enhanced myocardial T1‐weighted scout imaging has the potential for showing dispersed myocardial damage leading to increased myocardial mass in HCM, while the dense myocardial fibrosis correlated with reduced ejection fraction. J. Magn. Reson. Imaging 2009;30:778–784. © 2009 Wiley‐Liss, Inc.     

Parametric imaging of myocardial viability using 15O-labelled water and PET/CT: comparison with late gadolinium-enhanced CMR

Purpose

The perfusable tissue index (PTI) is a marker of myocardial viability. Recent technological advances have made it possible to generate parametric PTI images from a single [¹⁵O]H₂O PET/CT scan. The purpose of this study was to validate these parametric PTI images.

Methods

The study population comprised 46 patients with documented or suspected coronary artery disease who were studied with [¹⁵O]H₂O PET and late gadolinium-enhanced (LGE) cardiac magnetic resonance imaging (CMR).

Results

Of the 736 myocardial segments included, 364 showed some degree of LGE. PTI and perfusable tissue fraction (PTF) diminished with increasing LGE. The areas under the curve of the PTI and PTF, used to predict (near) transmural LGE on CMR, were 0.86 and 0.87, respectively. Optimal sensitivity and specificity were 91?% and 73?% for PTI and 69?% and 87?% for PTF, respectively.

Conclusion

PTI and PTF assessed with a single [¹⁵O]H₂O scan can be utilized as markers of myocardial viability in patients with coronary artery disease.