Perfusion and delayed enhancement imaging

A 54 year old male with diabetes and family history of CAD comes to a cardiologist for the first time for atypical chest pain. The patient reports having to grasp for air while in chest pain. A rest ECG is done at the office, in which nonspecific T wave changes were the only abnormality. Besides blood tests, the cardiologist orders an echocardiogram that shows reduced LV function and akinesis of the mid and apical anterior-septal walls, and a stress SPECT study that shows a perfusion defect in the same regions, with little reversibility on the rest images. Thinking this is most likely ischemic coronary disease, the cardiologist orders a cardiac MRI for viability evaluation prior to the invasive coronary angiography, which showed an occluded mid LAD artery with distal filling via collaterals. Given the presence of viability on the MRI scan, the patient successfully underwent PTCA of the mid-LAD lesion, and, two months later, LV function shows improvement and the patient is asymptomatic. Cardiologists are familiar with relying on a number of different imaging modalities for a thorough assessment of cardiovascular disorders. Coronary anatomy evaluation is usually performed using invasive catheterization or more recently by noninvasive MDCT scans. Global and regional myocardial function as well as structural abnormalities can be assessed with echo, MRI, and MDCT. Subclinical atherosclerosis is usually assessed via detection of coronary calcium using MDCT or EBCT scanners or via measuring carotid intima-media thickness with ultrasound; while stress tests for ischemia detection and quantification are usually performed with nuclear SPECT or PET, echo stress, or stress MRI imaging. Finally, myocardial fibrosis for viability and prognosis assessment is usually detected and quantified by MRI and nuclear techniques.