Cardiac MRI

The safety of G-CSF stimulation in patients with CAD has been questioned in two recent studies. Hill et al. [138] report the results of administration of 10 mcg/kg/day of G-CSF for 5 days in patients with chronic CAD n = 16). There was no clinical benefit as assessed by exercise stress testing and dobuta-mine cardiac MRI. Additionally two patients in the G-CSF group developed serious adverse events related to the therapy (one non-ST elevation MI one MI causing death). Zbinden et al. [139] also tested the efficacy of the same G-CSF dose in patients with chronic CAD ( = 7). The invasive endpoint collateral flow index was significantly better in the G-CSF treated patients when compared to the placebo group. However, two patients in the G-CSF treated group developed acute coronary syndrome during treatment. 

Tse et al. [130] have reported that transendocar-dial injection of autologous BMMNCs in eight patients with severe ischemic heart disease led to preserved left ventricular function. At 3-month follow-up, heart failure symptoms and myocardial perfusion had improved, especially in the ischemic region as shown by cardiac MRI. 

Slawson SE, Roman BB, Williams DS, Koretsky AP (1998) Cardiac MRI of the normal and hypertrophied mouse heart. Magnetic Resonance in Medicine 39 980-987 Szczepaniak LS, Babcock EE, Schick F et al. (1999) Measurement of intracellular triglyceride stores by H spectroscopy validation in vivo. American Journal of Physiology 276 E977-989... 

Cardiac MRI may have a role in risk stratification for SCD due to its ability to detect myocardial scar. The use of gadolinium, which accumulates in infarcted tissue, has allowed delayed enhancement MRI to detect scar burden. Early experiments in dog models performed by coronary artery occlusion compared acute and chronic infarcts to pathologic specimens of the dog heart postmortem (89,90). Delayed enhancement MRI was remarkably accurate in imaging the infarcted tissue in comparison to the pathologic specimen. The spatial extent of hyperenhancement was the same as the spatial extent of myocyte necrosis at every stage post-MI. Reversible ischemia did not show delayed gadolinium uptake. Thus, delayed enhancement MRI can distinguish between reversible and irreversible injury, and... 

The strongest predictor of mortality in pulmonary hypertension is RV function. The debate goes on as to the best modality to evaluate the RV function while prospectively following patients. Some of the options include various echo criteria, cardiac MRI, cardiac CT,... 

Cardiac applications of CT Interventional radiology Functional MRI and spectroscopy Interventionid MRI Cardiac MRI Radiation oncology Tissue oigineering" OR of the future Virtual endoscopy Virtual reality Therapeutic drug monitoring Telemedicine ... 

Thanks to the advancement of cardiac MRI, ultra-fast sequences with high temporal resolution are available on state of the art MR scanners. These sequences are represented by cine GRE sequence and dne-truFISP sequences that enables the evaluation of both esophageal motility and gastric-empty. 

ETTi et al. 2001). This technique has further pushed the envelope for cardiac MRI in a routine setting and based on the high spatial resolution of DE imaging, results have been shown to be even superior SPECT and FDG-PET with respect to subtle, nontransmural infarctions (Hunold et al. 2002 Wagner et al. 2003). 

In general, cardiac MRI shows a wide variety of clinically applicable techniques, while CT techniques are somewhat limited in their application. As the majority of symptoms and patients though are related to CAD, cardiac CT imaging still may cover a large patient population. 

In cases of positive findings (e.g., atherosclerotic wall changes, stenosis) in coronary CTA, further workup of patients is inevitable, as clinical cardiac CT is limited exclusively to image morphologic changes. Cardiac MRI may be suitable for further workup to identify the hemodynamic significance of CT detected coronary stenosis or even myocardial changes (e.g., silent infarctions). 

Hunold P et al. (2005) Myocardial late enhancement in contrast-enhanced cardiac MRI distinction between infarction scar and non-infarction-related disease. AJR Am J Roentgenol 184 1420-1426... 

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