Recent Myocardial Infarction: Assessment with Unenhanced T1-weighted MR Imaging

Goldfarb, James W.; Arnold, Sheeba; Han, Jing

doi:10.1148/radiol.2451061590

Cited by 50 publications

(43 citation statements)

References 35 publications

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“…This corresponds with previous studies 31,32 and can be explained by edema in the infarction. Therefore, any small contrast agent-induced reduction in T1 or T2 in the infarct/border zones may have been canceled by these intrinsic relaxation time differences.…”

Section: Contrast Agentsupporting

confidence: 93%

Molecular Magnetic Resonance Imaging of Myocardial Angiogenesis After Acute Myocardial Infarction

et al. 2010

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Background-Angiogenesis is a natural mechanism to restore perfusion to the ischemic myocardium after acute myocardial infarction (MI). Therapeutic angiogenesis is being explored as a novel treatment for MI patients; however, sensitive, noninvasive in vivo measures of therapeutic efficacy are lacking and need to be developed. Here, a molecular magnetic resonance imaging method is presented to noninvasively image angiogenic activity in vivo in a murine model of MI with cyclic Asn-Gly-Arg (cNGR)-labeled paramagnetic quantum dots (pQDs). The tripeptide cNGR homes specifically to CD13, an aminopeptidase that is strongly upregulated during myocardial angiogenesis. Methods and Results-Acute MI was induced in male Swiss mice via permanent ligation of the left anterior descending coronary artery. Molecular magnetic resonance imaging was performed 7 days after surgery and up to 2 hours after intravenous contrast agent administration. Injection of cNGR-pQDs resulted in a strong negative contrast that was located mainly in the infarcted myocardium. This negative contrast was significantly less in MI mice injected with unlabeled pQDs and in sham-operated mice injected with cNGR-pQDs. Validation with ex vivo 2-photon laser scanning microscopy revealed a strong colocalization of cNGR-pQDs with vascular endothelial cells, whereas unlabeled pQDs were mostly extravasated and diffused through the tissue. Additionally, 2-photon laser scanning microscopy demonstrated significant microvascular remodeling in the infarct/border zones compared with remote myocardium. Conclusions-cNGR-pQDs allow selective, noninvasive detection of angiogenic activity in the infarcted heart with the use of in vivo molecular magnetic resonance imaging and ex vivo 2-photon laser scanning microscopy. (Circulation. 2010; 121:775-783.)

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Section: Contrast Agentsupporting

confidence: 93%

Molecular Magnetic Resonance Imaging of Myocardial Angiogenesis After Acute Myocardial Infarction

et al. 2010

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“…The T1 mapping identifies a significant variation between normal and abnormal myocardium. It demonstrates the myocardial fibrosis among different myocardial disorders include ischemia [15], acute/chronic infraction [16], amyloidosis [17], diabetic [18], dilated and hypertrophic cardiomyopathy [19], and heart failure [8].…”

Section: T1 Mapping With Modified Look-locker Inversion "Molli" Recoverymentioning

confidence: 99%

“…T1 maps can be generated any time before or after contrast agent (e.g., gadolinium) administration [12]. The MOLLI sequence has been described, optimized, tested, and retested in phantoms and in large cohorts of healthy volunteers [12,14] as well as being applied in cardiomyopathies [8,15,17,19,20]. In addition, the T1 mapping with MOLLI has been validated against histopathology for assessment of myocardial fibrosis.…”

Section: T1 Mapping With Modified Look-locker Inversion "Molli" Recoverymentioning

confidence: 99%

Cardiac Magnetic Resonance T1 Mapping in Cardiomyopathies

Hamilton-Craig¹,

Strudwick²,

Galloway³

2017

Cardiomyopathies - Types and Treatments

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Cardiac magnetic resonance (CMR) imaging has been widely used to assess myocardial perfusion and scar and is the noninvasive reference standard for identification of focal myocardial fibrosis. However, the late gadolinium enhancement (LGE) technique is limited in its accuracy for absolute quantification and assessment of diffuse myocardial fibrosis by technical and pathophysiological features. CMR relaxometry, incorporating T1 mapping, has emerged as an accurate, reproducible, highly sensitive, and quantitative technique for the assessment of diffuse myocardial fibrosis in a number of disease states. We comprehensively review the physics behind CMR relaxometry, the evidence base, and the clinical applications of this emerging technique.

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“…30,31) Water has high T1 value and therefore T1 mapping can detect acute MI and assess the extent of myocardial damage with high sensitivity, specificity, and with significantly lower variability of T1 measurements as compared to T2-weighted (T2W) imaging. [32][33][34] It was also superior to T2W imaging in non STsegment elevation MI (NSTEMI). 33) In an animal study, T1 increases were found to be more pronounced in myocardium that was infarcted than in myocardium that was salvaged by reperfusion.…”

Section: Clinical Applications Of Native T1 Mappingmentioning

confidence: 99%

Native Myocardial T1 Mapping, Are We There Yet?

et al. 2016

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SummaryT1 or longitudinal relaxation time is one of the very fundamental magnetic resonance imaging (MRI) time constants and a tissue characterizing parameter. Only during the last decade did it become possible to quantify T1 values of the myocardium through T1 mapping. Evolving from only region of interest analysis and long acquisition times to the pixel-based parametric mapping and short breath-hold sequences, T1 mapping is reaching maturity among cardiac magnetic resonance (CMR) techniques. Both inversion recovery methods such as MOdified Look-Locker Inversion (MOL-LI) and Shortened MOLLI (ShMOLLI) and saturation recovery methods such as Saturation recovery Single-Shot Acquisition (SASHA) are available for T1 quantification with variable degrees of accuracy, precision, and reproducibility. Native (non-contrast) T1 values increase with edema, amyloid deposition, and fibrosis, while they decrease in fat or iron deposition in the myocardium. These features enabled significant expansion of the clinical applications of native T1 mapping where it provides high sensitivity and specificity and even acts as a disease biomarker or a predictor of prognosis. It is of particular usefulness in diffuse myocardial diseases where conventional CMR techniques might be deceiving. A brighter future for the technique is expected if certain challenges are to be faced, examples of which are the need for standardization of normal values, acquisition techniques, and improving analysis tools. (Int Heart J 2016; 57: 400-407)

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Recent Myocardial Infarction: Assessment with Unenhanced T1-weighted MR Imaging

Cited by 50 publications

References 35 publications

Molecular Magnetic Resonance Imaging of Myocardial Angiogenesis After Acute Myocardial Infarction

Molecular Magnetic Resonance Imaging of Myocardial Angiogenesis After Acute Myocardial Infarction

Cardiac Magnetic Resonance T1 Mapping in Cardiomyopathies

Native Myocardial T1 Mapping, Are We There Yet?

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