Dey Joyoni
Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655 USA.
IEEE Trans Nucl Sci. 2012 Apr;59(2):334-347. doi: 10.1109/tns.2011.2182660. Epub 2012 Feb 10.
SPECT is primarily used in the clinic for cardiac myocardial perfusion imaging. However, for SPECT, sensitivity is impaired due to the need for collimation. System resolution FWHM is poor as well (~ 1 cm). In this work the resolution of a curved detector was theoretically derived. The advantage of a curved detector over a flat detector with pinhole collimation was demonstrated for cardiac applications using theoretical derivations as well as a ray-tracing voxel-based forward projector. For the flat detector using parameters close to what was expected for the new multi-pinhole GE Discovery system, it is shown that using a paraboloid detector one may obtain a better system resolution (about 29% better on the average), keeping same pinhole opening. Alternately, sensitivity gains of as much as 2.25 may be obtained, for similar resolutions as a flat detector by just using a different pinhole with higher hole-diameter.
单光子发射计算机断层扫描（SPECT）主要用于临床心脏心肌灌注成像。然而，对于SPECT而言，由于需要准直，其灵敏度会受到影响。系统的半高宽分辨率也很差（约1厘米）。在这项工作中，从理论上推导了曲面探测器的分辨率。通过理论推导以及基于体素的光线追踪前向投影器，证明了在心脏应用中，曲面探测器相对于带有针孔准直的平面探测器的优势。对于使用接近新型多针孔GE Discovery系统预期参数的平面探测器，结果表明，在保持相同针孔孔径的情况下，使用抛物面探测器可以获得更好的系统分辨率（平均提高约29%）。或者，通过使用具有更大孔径的不同针孔，在与平面探测器相似的分辨率下，灵敏度可提高多达2.25倍。
