Below are images of the Data Spectrum anthropomorphic torso obtained at various imaging times with the CardiArc® scanner and with a state-of-the-art, dual-detector SPECT system. The conventional system had two detectors at 90° to each other - both equiped with low-energy, high-resolution (LEHR) collimators.
The CardiArc® images were obtained on a clinical prototype system. This machine uses CZT (cadmium zinc telluride) semiconductor detectors, but the detector arc was only half-filled. The CardiArc® scan times indicated are normalized to those of a production system with sodium-iodide detectors. All indicated times are normalized for tracer decay.
Heart Chamber
450microCuries
Background
1.3 mCi
It is useful to recall that the activity in the phantom is similar to that of a typical rest Tc99m study. A stress exam may have up to 2-3 times this activity.
Two cold "defects" were placed in the heart portion of the phantom, one at the anterior wall (orange arrows) and one at the inferobasal wall (yellow arrows).
The CardiArc® images show higher lesion contrast and better target-to-background ratios at all scan speeds studied. The improvement in image quality, compared to the standard system, becomes greater as scan time is shortened.
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