Reading the Human Heart – Part 2

How do you read another's heart? In Part 1 of this series, we learned how cardiologists use the Biograph TruePoint PET∙CT to image the human heart and improve a patient's treatment options. But how does the technology work? And what's so special about this latest product from Siemens Medical Systems, a company that developed its first PET scanner over 30 years ago? The secret is in the software – visual analysis software known as molecular imaging (MI) clinical engines.

MI Clinical Engines

The Biograph TruePoint PET•CT uses several MI clinical engines for cardiology, neurology and oncology. There are two basic types of engines for cardiac imaging : positron emission tomography and computed tomography (PET • CT), and single positron emission tomography and computed tomography (SPEC • CT). Both types of MI clinical engines help doctors determine the size, location, nature, and extent of disease at an early stage. By using scans from tracers targeted at specific cells, these MI clinical engines reconstruct data sets and determine differences in geometry and other factors. Recent advancements have greatly improved imaging by collecting more data and allowing for a large decrease in the given dose.

MI Cardiology PET CT Engines

MI Cardiology PET•CT Engines provide doctors with many valuable features. Examples include the visualization of cardiac images; computed tomography angiography (CTA) heart isolation with automatic overlay of coronary CT data on perfusion (this is the change in pressure over the vascular resistance; in other words, the process of delivering blood from an artery to a capillary bed) or viability PET images; and metabolic PET quantification. MI Cardiology PET • CT Engines also provide calcium scoring and automatic coronary tree-segmentation from CTA image sets, coronary plaque analysis and coronary stenosis estimation, and four-dimensional (4D) cardiac CT visualization.

So much for the features. What are the benefits? For starters, a CTA provides a non-invasive way to obtain medical images of coronary arteries. Calcium scoring, a test which determines the amount of calcium on the walls of the arteries of the heart, helps doctors detect early signs of heart disease and determine the severity of existing problems. Coronary stenosis estimation is a way to determine the narrowness of a blood vessel, a condition which may be caused by a birth defect, infection, inflammation, or neoplasm.

SPECT•CT Cardiology Engines

SPECT•CT Cardiology Engines also provide doctors with a wealth of features. Examples include the quantification of perfusion, gated and blood pool SPECT; correlation with normal data base; calcium scoring quantification; correlation with MPI slices and fused ventricular resynchronization therapy (VRT); automatic heart isolation; and alpha blended visualization. Because SPECT•CT is targeted at specific cells, these MI clinical engines let doctors focus on a particular area, making it easier to rule out diseases. In addition, because the radioisotopes in SPECT•CT have longer half-lives and last longer, doctors can track targeted cells over time and look for changes. Using these images, cardiologists can provide even more precise diagnoses..

Looking Backward, Moving Forward

In 1976, Siemens Medical Systems introduced its first commercial PET system. Since then, the company has amazed doctors and biomedical engineers alike with continuous improvements. During the past 31 years, Siemens has gone from a machine that contained a hexagonal array of 66 Nal (TI) detectors to a high-definition PET with myriad features.

If you look at the timeline from the Siemens demo, you'll notice that like the medical world itself, the PET machine has changed dramatically during the last few years. Hopefully, these rolling improvements will continue during the years to come. In the meantime, let's keep putting one foot in front of the other.

Resources:

Demo link

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Siemens biograph info site

http://www.medical.siemens.com/webapp/wcs/stores/servlet/ProductDisplay~q_catalogId~e_-11~a_catTree~e_100010,1007660,1004808,1004804,1004806,1004807,14255~a_langId~e_-11~a_productId~e_143899~a_storeId~e_10001.htm

Growth in RPI's Biomedical Program includes bio-imaging

RPI's Bio-imaging Current Research

http://www.rpi.edu/research/magazine/fall05/radiation_1.html