The effect of 1.5 T cardiac magnetic resonance on human circulating leucocytes (original) (raw)

Biological Effects of Cardiac Magnetic Resonance on Human Blood CellsCLINICAL PERSPECTIVE

Circulation: Cardiovascular Imaging, 2015

I maging is pivotal to modern health care and is an essential component of many patients' diagnostic scenarios. 1 In recent decades, the use of nonionizing techniques in cardiovascular imaging has grown considerably, mainly because of the increased use of ultrasound and magnetic resonance imaging (MRI). 2 Cardiac magnetic resonance (CMR) imaging offers expanding potential in research and diagnosis, with tissue discrimination unequalled by any other imaging technique. 3 MRI uses a powerful electromagnetic field to induce a resonance effect of some atomic nuclei in the body. 4 MRI is thought to have no long-term side effects, conversely to ionizing radiation-based imaging techniques (x-ray angiography, coronary computed tomographic angiography, and nuclear imaging), which can induce cell death or persistent DNA damage, resulting in mutagenesis, carcinogenesis, and genomic instability. 5-8 However, genotoxic concerns have been recently raised. 9,10 Several studies reported an immediate post-MRI increase of histone H2AX phosphorylation (γ-H2AX) in lymphocytes, a marker of DNA double-strand breaks, in a magnitude comparable with damages produced by low-dose ionizing radiation. 11-13 Whether MRI-induced DNA damage can persist or evolve over time is unknown. In this study, we sought to evaluate the early and late biological responses of blood cells (DNA double-strand breaks, cell count, cell death, and cell activation) to CMR in normal subjects. See Editorial by Kaufmann See Clinical Perspective Methods Population The study was approved by the local Institutional Human Research Committee and conducted according to the ethical guidelines and principles of the international Helsinki declaration. After informed consent, 20 healthy male subjects ≥20 years (31.4±7.9 years) with normal physical cardiac examination (with no systolic nor diastolic murmur), normal ECG, without history of any cardiovascular disease or history of current smoking, no chronic excessive alcohol consumption, not currently on medical therapy with cardio-active drugs were prospectively recruited. Every volunteer was asked not to practice Background-Cardiac magnetic resonance (CMR) is increasingly used for the diagnosis and management of cardiac diseases. Recent studies have reported immediate post-CMR DNA double-strand breaks in T lymphocytes. We sought to evaluate CMR-induced DNA damage in lymphocytes, alterations of blood cells, and their temporal persistence. Methods and Results-In 20 prospectively enrolled healthy men (31.4±7.9 years), blood was drawn before and after (1-2 hours, 2 days, 1 month, and 1 year) unenhanced 1.5T CMR. Blood cell counts, cell death, and activation status of lymphocytes, monocytes, neutrophils, and platelets were evaluated. The first 2-hour post-CMR were characterized by a small increase of lymphocyte B and neutrophil counts and a transient drop of total lymphocytes because of a decrease in natural killer cells. Among blood cells, only neutrophils and monocytes displayed slight and transient activation. DNA double-strand breaks in lymphocytes were quantified through flow cytometric analysis of H2AX phosphorylation (γ-H2AX). γ-H2AX intensity in T lymphocytes did not change early after CMR but increased significantly at day 2 ≤1 month before returning to baseline levels of 1-year post-CMR. Conclusions-Unenhanced CMR is associated with minor but significant immediate blood cell alterations or activations figuring inflammatory response, as well as DNA damage in T lymphocytes observed from day 2 until the first month but disappearing at 1-year follow-up. Although further studies are required to definitely state whether CMR can be used safely, our findings already call for caution when it comes to repeat this examination within a month. (Circ Cardiovasc Imaging. 2015;8:e003697.

Cardiovascular nuclear magnetic resonance: basic and clinical applications

Journal of Clinical Investigation, 2003

Felix Bloch (1) at Stanford University and Edward Purcell and his colleagues (2) at Harvard University reported the phenomenon of NMR independently in 1946. As a result, Bloch and Purcell shared the 1952 Nobel Prize in Physics. Between 1950 and 1970, NMR spectroscopy was developed and used to analyze chemical and physical molecular structure. In 1971, Raymond Damadian reported that the NMR relaxation times of tumors differed from those of normal tissue, suggesting for the first time that magnetic resonance (MR) might be used for the detection of disease (3). In 1973, Paul Lauterbur was the first to report that images could be generated by NMR using small test tube samples of water and oil (4). Rather than creating a homogeneous magnet field by adjusting the "shimming" magnets to minimize field inhomogeneity, Lauterbur applied a magnetic field gradient to induce inhomogeneity in a planned way, providing a method to encode different parts of the substance to be imaged. He generated images using a technique analogous to that employed in x-ray computed tomography, known as back-projection-reconstruction. Two years later, Richard Ernst and colleagues proposed using the mathematical operation of Fourier transformation to create a spatial image from the frequencies generated by radiowave excitation within a magnetic field (5). It was an additional five years before Ernst and colleagues' ideas were applied, and they quickly formed the basis of most modern imaging techniques. Supposedly to avoid confusion with nuclear medicine, the clinical NMR imaging tool became known as magnetic resonance imaging (MRI) in the late 1970s. In 1977, Damadian and colleagues demonstrated MRI of the whole body (6). In this same year, Peter Mansfield developed the echo-planar imaging (EPI) technique for high-speed imaging . Also in that year, both Jacobus and colleagues (8) and Garlick and associates (9) published the first NMR phosphorus spectra from isolated perfused rat hearts, which paved the way for numerous publications on myocardial high-energy phosphate metabolism in the heart. In 1980 Goldman and his colleagues described the potential applications of NMR imaging in the assessment of the cardiovascular system (10). Many of the predictions made in that paper have gradually approached fruition. Despite the considerably more frequent use of cardiovascular MR (CMR) imaging compared with CMR spectroscopy, currently, there is significant clinical information to be ascertained from molecules in the myocardium that can be detected by clinical spectroscopy. This article will describe the state-of-the-art of imaging and spectroscopy and provide a framework for suggesting the future applications of this formidable technology.

Cardiovascular magnetic resonance for the clinical cardiologist

Canadian Journal of Cardiology, 2007

C ardiovascular magnetic resonance (CMR) has found widespread use as an important tool in the cardiologists' armamentarium over the past decade, mainly because of its superior diagnostic accuracy and ability to perform complete anatomical and functional assessment in a single study without ionizing radiation. The present paper reviews specific applications of CMR that may be useful for the clinical cardiologist who is less familiar with this imaging modality (Table 1).

Cardiovascular magnetic resonance: contribution to the exploration of cardiomyopathies

Medicine and Pharmacy Reports

Introduction. Magnetic resonance imaging is a non-invasive and non-irradiating imaging method, complementary to cardiac ultrasound in the assessment of cardiovascular disease and implicitly of cardiomyopathies. Although it is not a first intention imaging method, it is superior in the assessment of cardiac volumes, left ventricular ejection fraction, in the analysis of cardiac wall dyskinesia and myocardial tissue characteristics with and without using a contrast agent. The purpose of this paper is to review the current knowledge regarding cardiovascular magnetic resonance imaging (CMR) and its applications in cardiomyopathy analysis. Methods. In order to create this review, relevant articles were searched and analyzed by using MeSH terms such as: "cardiac magnetic resonance imaging", "cardiomyopathy", "myocardial fibrosis". Three main international databases PubMed, Web of Science and Medscape were searched. We carried out a narrative review focused ...

Cardiac Magnetic Resonance in Hypertensive Heart Disease: Time for a New Chapter

Diagnostics

Hypertension is one of the most important cardiovascular risk factors, associated with significant morbidity and mortality. Chronic high blood pressure leads to various structural and functional changes in the myocardium. Different sophisticated imaging methods are developed to properly estimate the severity of the disease and to prevent possible complications. Cardiac magnetic resonance can provide a comprehensive assessment of patients with hypertensive heart disease, including accurate and reproducible measurement of left and right ventricle volumes and function, tissue characterization, and scar quantification. It is important in the proper evaluation of different left ventricle hypertrophy patterns to estimate the presence and severity of myocardial fibrosis, as well as to give more information about the benefits of different therapeutic modalities. Hypertensive heart disease often manifests as a subclinical condition, giving exceptional value to cardiac magnetic resonance as a...

Cardiomyopathies: focus on cardiovascular magnetic resonance

British Journal of Radiology, 2011

Cardiomyopathies (CMPs) are a group of often inherited diseases characterised by abnormalities and associated dysfunction of heart muscle. In the past decade, cardiovascular magnetic resonance (CMR) has emerged as a powerful tool in their assessment, providing data that are complementary to other aspects of clinical evaluation. Key advantages of CMR are three-dimensional visualisation of the heart and its relationship to thoracic structures; gold-standard quantification of cardiac volumes and function, which can safely be repeated over time (no ionising radiation is involved); and tissue characterisation to detect focal scar and fatty infiltration. This paper reviews the role of CMR in the clinical assessment of patients with CMPs.

Cardiovascular magnetic resonance: Stressing the future

World Journal of Cardiology, 2019

Non-invasive cardiac stress imaging plays a central role in the assessment of patients with known or suspected coronary artery disease. The current guidelines suggest estimation of the myocardial ischaemic burden as a criterion for revascularisation on prognostic grounds despite the lack of standardised reporting of the magnitude of ischaemia on various non-invasive imaging methods. Future studies should aim to accurately describe the relationship between myocardial ischaemic burden as assessed by cardiovascular magnetic resonance imaging and mortality.