scholarly journals Exercise training improves cardiac performance in diabetes: in vivo demonstration with quantitative cine-MRI analyses

2007 ◽  
Vol 102 (2) ◽  
pp. 665-672 ◽  
Author(s):  
Rajprasad Loganathan ◽  
Mehmet Bilgen ◽  
Baraa Al-Hafez ◽  
Svyatoslav V. Zhero ◽  
Mohammed D. Alenezy ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Exercise Training ◽  
Diabetic Cardiomyopathy ◽  
Cardiac Cycle ◽  
Left Ventricular ◽  
Cycle Phase ◽  
Resonance Imaging ◽  
Catabolic State

Diabetic cardiomyopathy is a distinct myocardial complication of the catabolic state of untreated insulin-dependent diabetes mellitus in the streptozotocin-induced diabetic rat. Exercise training has long been utilized as an effective adjunct to pharmacotherapy in the management of the diabetic heart. However, the in vivo functional benefit(s) of the training programs on cardiac cycle events in diabetes are poorly understood. In this study, we used three groups of Sprague-Dawley rats (sedentary control, sedentary diabetic, and exercised diabetic) to assess the effects of endurance training on the left ventricular (LV) cardiac cycle events in diabetes. At the end of 9 wk of exercise training, noninvasive cardiac functional evaluation was performed by using high-resolution magnetic resonance imaging (9.4 T). An ECG-gated cine imaging protocol was used to capture the LV cardiac cycle events through 10 equally incremented phases. The cardiac cycle phase volumetric profiles showed favorable functional changes in exercised diabetic group, including a prevention of decreased end-diastolic volume and attenuation of increased end-systolic volume that accompanies sedentary diabetes. The defects in LV systolic flow velocity, acceleration, and jerk associated with sedentary diabetes were restored toward control levels in the trained diabetic animals. This magnetic resonance imaging study confirms the prevailing evidence from earlier in vitro and in vivo invasive procedures that exercise training benefits cardiac function in this model of diabetic cardiomyopathy despite the extreme catabolic state of the animals.

scholarly journals Analyses of displacement of the heart and its substructures caused by cardiac movement and identification of compensatory margins based on breath-hold electrocardiograph-gated 4-dimensional magnetic resonance imaging for oesophageal radiotherapy

2020 ◽  
Author(s):  
Guanghui Yang ◽  
Chengrui Fu ◽  
Guanzhong Gong ◽  
Jing Zhang ◽  
Qian Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Papillary Muscle ◽  
Cardiac Cycle ◽  
Left Ventricular ◽  
Breath Hold ◽  
Resonance Imaging ◽  
4D Mri ◽  
Planning Ct ◽  
Anterior Posterior

Abstract Background: Cardiac movement can affect the accuracy of the evaluation of the location of heart and its substructures by planning computed tomography (CT). We aimed to measure the margin displacement and calculate compensatory margins through breath-hold electrocardiograph (ECG)-gated 4-dimensional magnetic resonance imaging (4D-MRI) for oesophageal radiotherapy.Methods: The study enrolled 10 patients with oesophageal radiotherapy plans and pretreatment 4D-MRI data. The displacement of the heart and its substructures was measured between the end of the systolic and diastolic phases in one cardiac cycle. The compensatory margins were calculated by extending the planning CT to cover the internal target volume (ITV) of all structures. Differences between groups were tested with the Kruskal-Wallis H test.Results: The extent of movement of the heart and its substructures during one cardiac cycle were approximately 4.0-26.1 mm in the anterior-posterior (AP),left-right (LR), and cranial-caudal (CC) axes, and the compensatory margins should be applied to the planning CT by extending the margins by 1.7, 3.6, 1.8, 3.0, 2.1, and 2.9 mm for the pericardium, 1.2, 2.5, 1.0, 2.8, 1.8, and 3.3 mm for the heart, 3.8, 3.4, 3.1, 2.8, 0.9, and 2.0 mm for the interatrial septum, 3.3, 4.9, 2.0, 4.1, 1.1, and 2.9 mm for the interventricular septum, 2.2, 3.0, 1.1, 5.3, 1.8, and 2.4 mm for the left ventricular muscle (LVM), 5.9, 3.4, 2.1, 6.1, 5.4, and 3.6 mm for the antero-lateral papillary muscle (ALPM), and 6.6, 2.9, 2.6, 6.6, 3.9, and 4.8 mm for the postero-medial papillary muscle (PMPM) in the anterior, posterior, left, right, cranial, and caudal directions.Conclusions: The locations of the heart and its substructures determined by planning CT were not able to represent the true positions due to cardiac movement, and compensatory margins can be applied to decrease the influence of movement.

Abstract 1910: Monitoring of Inflammatory Processes By In Vivo 19F Magnetic Resonance Imaging

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Ulrich Flögel ◽  
Zhaoping Ding ◽  
Hendrik Hardung ◽  
Sebastion Jander ◽  
Gaby Reichwein ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Positive Contrast ◽  
Posterior Wall ◽  
Reticuloendothelial System ◽  
Left Ventricular ◽  
Blood Substitutes ◽  
Resonance Imaging ◽  
Inflammatory Processes

This study was aimed at developing a new approach for in vivo detection of inflammation by 19 F magnetic resonance imaging (MRI) using biochemically inert emulsified perfluorocarbons (PFCs). PFCs have been clinically used as blood substitutes and are known to be phagocytized by the reticuloendothelial system. Local inflammation was provoked in two murine models of acute cardiac and cerebral ischemia, respectively, followed by intravenous injection of PFCs. A typical example of anatomically matching 1 H and 19 F images obtained at 9.4 Tesla 4 days after myocardial infarction is shown below. The 1 H image (left) clearly shows the presence of ventricular dilatation and wall thinning within the infarcted area (I), and in the corresponding 19 F image (middle) a signal pattern matched in shape of the free left ventricular wall. Merging of these images (right) confirms the localization of PFCs within the anterior, lateral, and posterior wall. In all animals (n=8) studied, 19 F signal was also detected in the adjacent chest tissue, where thoracotomy for infarction was performed (T). No background signal from other tissue was observed. Repetitive MRI revealed in both injury models a time-dependent infiltration of injected PFCs into infarcted areas, and histology demonstrated a colocalization of PFCs with cells of the monocyte-macrophage system. Using rhodamine-labelled PFCs, circulating monocytes/macrophages were identified to be the main cell fraction taking up injected PFCs. In conclusion, PFCs can serve as positive contrast agent for detection of inflammatory processes by MRI, permitting high spatial resolution and an excellent degree of specificity due to lack of any 19 F background.

scholarly journals Noninvasive stratification of postinfarction rats based on the degree of cardiac dysfunction using magnetic resonance imaging and echocardiography

2017 ◽  
Vol 312 (5) ◽  
pp. H932-H942 ◽  
Author(s):  
Jan Magnus Aronsen ◽  
Emil Knut Stenersen Espe ◽  
Kristine Skårdal ◽  
Almira Hasic ◽  
Lili Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Heart Failure ◽  
Magnetic Resonance ◽  
Clustering Algorithm ◽  
Left Ventricular ◽  
Resonance Imaging ◽  
Cardiovascular Research ◽  
Lung Weight ◽  
Magnetic Resonance Imaging Mri

The myocardial infarction (MI) rat model plays a crucial role in modern cardiovascular research, but the inherent heterogeneity of this model represents a challenge. We sought to identify subgroups among the post-MI rats and establish simple noninvasive stratification protocols for such subgroups. Six weeks after induction of MI, 49 rats underwent noninvasive examinations using magnetic resonance imaging (MRI) and echocardiography. Twelve sham-operated rats served as controls. Increased end-diastolic left ventricular (LV) pressure and lung weight served as indicators for congestive heart failure (CHF). A clustering algorithm using 13 noninvasive and invasive parameters was used to identify distinct groups among the animals. The cluster analysis revealed four distinct post-MI phenotypes; two without congestion but with different degree of LV dilatation, and two with different degree of congestion and right ventricular (RV) affection. Among the MRI parameters, RV mass emerged as robust noninvasive marker of CHF with 100% specificity/sensitivity. Moreover, LV infarct size and RV ejection fraction further predicted subgroup among the non-CHF and CHF rats with excellent specificity/sensitivity. Of the echocardiography parameters, left atrial diameter predicted CHF. Moreover, LV end-diastolic diameter predicted the subgroups among the non-CHF rats. We propose two simple noninvasive schemes to stratify post-MI rats, based on the degree of heart failure; one for MRI and one for echocardiography. NEW & NOTEWORTHY In vivo phenotyping of rats is essential for robust and reliable data. Here, we present two simple noninvasive schemes for the stratification of postinfarction rats based on the degree of heart failure: one using magnetic resonance imaging and one based on echocardiography.

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