High Performance
The Attrius has one of the highest 2D sensitivity systems in the industry. Several factors impact sensitivity including size of detector, distance from patient, detector encoding scheme, parallelism of the electronics, and crystal packing fraction. The Attrius achieves its high sensitivity required for exceptional cardiac imaging by placing more crystal mass around the object being imaged resulting in fewer gaps for housing or reflective material.
Positron’s patented, staggered crystal design delivers a unique, shorter septa. Short septa permit the use of a smaller diameter detector ring, allowing the detectors to be closer to the subject. Closer detectors allow for a higher sensitivity without decreasing the size of the aperture. Being closer to the patient requires the Attrius detector to be capable of accepting and processing higher fluxes of events, as compared to other PET scanners, for the same amount of activity in the patient.
The dynamic quantitative measurement of blood flow is dependent upon two factors within a scanner; its sensitivity and its count-rate capability. Combined with its extraordinary sensitivity, the Attrius scanner is capable of imaging ALL available PET isotopes. With more counts obtained, physicians can more accurately define the locale of a lesion or perfusion defect.
Cardiac Specific Software
Positron’s technology, spanning from hardware to software, was designed in partnership with an industry leading cardiologist. Our software was developed specifically to permit easy interpretation of even the most complex clinical cases. The Attrius has robust, cardiac specific imaging software designed to execute on multiple processors in order to optimize simultaneous acquisitions and processing capabilities. The system is designed to provide concurrent acquisition, reconstruction, image processing and display, as well as data archiving, without interference.
Multiple Acquisition Modes
The acquisition window provides a user friendly interface to control all aspects of data acquisition. When the data acquisition process box of any automated protocol is activated, the acquisition window is displayed.
Simultaneous Gating and Flow Acquisitions
The Attrius acquisition buffering system was designed to accommodate simultaneous function and flow data. The users can choose between time or phase mode gating. Retrospective analysis and formatting makes flow measurements quick and easy.
Traditional Cardiac Display
Positron’s traditional cardiac display color format can be customized to the interpreter’s preferences. This selection displays seven images from each viewing angle (HLA, VLA, and CSA) for each set, as well as the scaled bulls-eye images for each study and the relative and absolute ratio maps.
Proprietary Mercator Topographic Projection with Comparison to Normal Database
Positron’s proprietary Mercator Topographic Projection was developed for the most complicated anatomical reference imaging today. The visual comparison of rest/stress cardiac positron emission tomography 
indicates coronary flow reserve for diagnosing and assessing the severity of coronary artery disease. An accurate, rapid, and automated method for comparison and quantitation of paired cardiac PET studies has been developed to analyze size, intensity, statistical significance of and changes in perfusion or metabolism.
Coronary Artery Overlay/Coronary Territory
To map precise myocardial perfusion anatomy, Positron correlated detailed coronary arteriographic anatomy for every coronary artery and all secondary branches in the heart that had flow-limiting stenosis with corresponding specific, circumscribed, myocardial perfusion defects by positron emission tomography.
The software was developed in partnership with K. Lance Gould, M.D., who imaged eight hundred ninety-five patients with abnormal coronary arteriograms showing any visible coronary artery narrowing of greater than 10% diameter stenosis. These patients underwent positron emission tomography perfusion imaging at rest and after dipyridamole stress; the data obtained was processed automatically into 3-dimensional topographic displays of relative radionuclide uptake in anterior, septal, left lateral, and inferior quadrant views, without attenuation artifacts, depth-dependent resolution, or spatial distortion of polar displays.
The selection criterion for detailed anatomic analysis was the presence of a discrete, localized, moderate to severe, dipyridamole induced perfusion defect, defined by automated algorithms as one quadrant view outside two standard deviations of healthy control subjects with which a specific stenotic coronary artery and/or its secondary branches could be correlated unequivocally on the coronary arteriogram for mapping precise perfusion anatomy, not for determining sensitivity or specificity.
Proprietary X-Y Shift Correction Algorithm
The integration of a motion algorithm program is essential to ensure the highest level of technical quality of any given scan. Positron recognizes that if the patient moved between the attenuation and emission acquisitions, then significant artifacts can occur in the image and bulls-eye data. Positron’s motion correction shift procedure resolves X-Y patient movement and is used to view the alignment of the attenuation and emission images and determine if there is a position error between these images. If a significant error exists the data can be reprocessed to correct for these shifts in position.
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Contact us directly: attrius@positron.com
