Cardiac Magnetic Resonance Imaging for the Investigation of Cardiovascular Disorders. Part 1: Current Applications

Abstract

Cardiac magnetic resonance imaging is a robustC ardiac magnetic resonance imaging (CMR) has emerged as a robust noninvasive technique for the investigation of cardiovascular disorders. Several technical advances have facilitated the growth of CMR by enabling high-quality diagnostic imaging despite the challenges inherent to cardiac imaging: cardiorespiratory motion and flowing blood. Considerable research evidence and years of clinical experience have shown the diagnostic and prognostic usefulness of CMR in a wide spectrum of cardiovascular disorders. The coming-of-age of CMR and its widening span of applications have generated excitement, as well as uncertainty, regarding its potential clinical use and its role vis-à-vis conventional imaging techniques. The purpose of this article is to highlight the current (Part 1) and emerging (Part 2) applications of CMR, in order to assist the referring physician in the decision-making process. Current Applications Analysis of Ventricular Function and VolumesCardiac magnetic resonance imaging has evolved into an accurate and well-validated tool for the evaluation of cardiac function. The high reproducibility of CMR-derived measures of cardiac function makes CMR an ideal technique for the longitudinal follow-up of patients.1 This superior reproducibility has also led to increased use of CMR as a reference standard for other techniques and as a surrogate outcome measure in drug studies. In fact, the use of CMR has facilitated reduction in the required sample sizes for such studies by as much as 10-fold, in turn decreasing overall study costs by up to 80%. 2-4Cardiac-function evaluation on CMR is based on true volumetric quantification, which is performed by dividing the ventricles into several smaller and relatively simpler subvolumes for the calculation of global ventricular volume (the disc-summation technique). This technique does not use the geometric assumptions that form the basis of planar imaging techniques like echocardiography. The current workhorse of functional CMR is the balanced steady-state free precession (SSFP) sequence, which provides excellent delineation of the endocardial-blood pool interface. When combined with parallel imaging techniques, the SSFP sequence enables the acquisition of electrocardiographic (ECG)-gated images within breath-hold times as short as 6 seconds per slice while maintaining sufficient spatial resolution. Images are acquired in the true short-axis plane from the base of the heart to the apex (Fig. 1). For image

Synthesis and functional evaluation of chiral dendrimer-triamine-coordinated Gd complexes with polyaminoalcohol end groups as highly sensitive MRI contrast agents

“…The residue was purified by flash column chromatography (SiO 2 , 100% CHCl 3 to 100% ethyl acetate) to give 3.06 g (7.65 mmol, 75%) of 7 as an orange oil. 1 (8). 7 (3.06 g, 7.65 mmol) and 10 mL of CH 2 Cl 2 were added to a reactor filled with argon.…”

Cardiac Magnetic Resonance Imaging for the Investigation of Cardiovascular Disorders. Part 2: Emerging Applications

“…As discussed in Part 1 of this review, 1 high contrast-to-noise ratio in DE-MR imaging is achieved by suppressing the signal from the normal, unaffected myocardium. However, in patients with diffuse interstitial fibrosis, defining the unaffected myocardium can be difficult, which limits the usefulness of DE-MR imaging for detecting diffuse myocardial processes and for quantifying the extent of extracellular matrix (ECM) expansion.…”

“…Part 1 of this review highlighted the mainstream applications of CMR that are now routinely used for diagnosis, risk stratification, and case management. 1 In this section, we provide an overview of the principles and potential applications of emerging CMR techniques that seek to characterize the myocardial substrate in both health and disease. These techniques offer the ability to noninvasively delineate pathophysiologic processes in vivo and, therefore, to expand our understanding of cardiovascular disorders.…”