Coronary arteries, imaging

We have reported a close association between plaque burden and impaired kidney function in type 1 diabetics using MRl imaging [13]. With the appearance of new generation scanners MSCT imaging most certainly in the near future will be available widespread in health communities. Clinical use and evaluation of non-invasive coronary artery imaging should focus on patients predisposed to atherosclerosis including those with diabetes. 

Lu B, Mao SS, Zhuang N et al. (2001) Coronary artery motion during the cardiac cycle and optimal ECG triggering for coronary artery imaging. Invest Radiol 36 250-256... 

Noninvasive Coronary Artery Imaging in Cardiac Surgery 240... 

Presently, only adenosine itself is approved for clinical use. It is used widely in the treatment of supraventricular tachycardia and in cardiac stress imaging to assess coronary artery disease [5]. Other agonists and antagonists and an allosteric modulator of the Ai receptor are in clinical trials for a variety of indications. 

Figure 2.1 illustrates normal myocardial perfusion by PET using Rubidium ( Rb) at rest and after dipyridamole stress in 3D views. A coronary arterial map is overlaid on the perfusion image or alternatively an arterial distribution map as a precise perfusion atlas of the coronary artery tree and all its secondary and tertiary branches [25]. 

In Fig. 2.2, the PET perfusion images show severe stenosis or occlusion of the left circumflex (LCx) and right (RCA) coronary arteries with a moderately severe stenosis of the left anterior descending (LAD) coronary artery proximal to its second diagonal branch. The ejection fraction (EF) and regional LV contraction were normal. Therefore, this example illustrates purely ischemic myocardium without scar and without injured or poorly contracting myocardium. 

Fig. 2.2 Positron emission tomography (PET) perfusion images showing severe stenosis/ occlusion of the left circumflex (LCx) and right (RCA) coronary arteries with...

For patients with chronic CAD, nuclear imaging is essential for addressing the following major clinical issues (i) detection of ischemic myocardium, (ii) differentiation between viable hibernating or stunned myocardium and scar tissue in mechanically dysfunctional regions, and (ill) risk stratification for future major adverse events. Such information provides the basis for percutaneous coronary intervention (PCI) or coronary artery bypass (CAB) surgery and assessing their outcomes based on detection of residual ischemia and recovery of contractile function. 

Bonow RO. Functional evaluation of patients with coronary artery disease selection of appropriate pharmacologic agents and imaging modalities. Eur Heart J 1995 16 SupplM ll-16... 

Di Carli MF, Davidson M, Little R, Khanna S, Mody FV, Brunken RC et al. Value of metabolic imaging with positron emission tomography for evaluating prognosis in patients with coronary artery disease and left ventricular dysfunction. Am J Cardiol 1994 73 527-533... 

Bonow RO, Dilsizian V, Cuocolo A, Bacharach SL. Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction. Comparison of thallium scintigraphy with reinjection and PET imaging with 18F-fluorodeoxyglucose. Circulation 1991 83 26-37... 

Perin EC, Silva GV, Sarmento-Leite R, Sousa AL, Howell M, Muthupillai R, Lambert B, Vaughn WK, Flamm SD. Assessing myocardial viability and infarct transmurality with left ventricular electromechanical mapping in patients with stable coronary artery disease validation by delayed-enhancement magnetic resonance imaging. Circulation 2002 106 957-961. 

Fig. 8.2 (A) Intravascular ultrasound (IVUS) image of a coronary artery using Revolution 45 MHz IVUS imaging catheter. (B) Plaque composition imaging using volcano VH IVUS system. Green areas represent Fibrous plaque. Yellow is fibro-fatty areas. Red is the necrotic core and white represents areas of dense calcium...

In subsequent investigations, [ FIPFBG PET was used to image canine pheochromocytomas and to characterize the area at risk in a canine coronary artery occlusion model [180, 181]. 

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