Gindi G R, Arendt J, Barrett H H, Chiu M Y, Ervin A, Giles C L, Kujoory M A, Miller E L, Simpson R G
Med Phys. 1982 May-Jun;9(3):324-39. doi: 10.1118/1.595171.
The statistical quality of conventional nuclear medical imagery is limited by the small signal collected through low-efficiency conventional apertures. Coded-aperture imaging overcomes this by employing a two-step process in which the object is first efficiently detected as an "encoded" form which does not resemble the object, and then filtered (or "decoded") to form an image. We present here the imaging properties of a class of time-modulated coded apertures which, unlike most coded apertures, encode projections of the object rather than the object itself. These coded apertures can reconstruct a volume object nontomographically, tomographically (one plane focused), or three-dimensionally. We describe a new decoding algorithm that reconstructs the object from its planar projections. Results of noise calculations are given, and the noise performance of these coded-aperture systems is compared to that of conventional counterparts. A hybrid slit-pinhole system which combines the imaging advantages of a rotating slit and a pinhole is described. A new scintillation detector which accurately measures the position of an event in one dimension only is presented, and its use in our coded-aperture system is outlined. Finally, results of imaging test objects and animals are given.
传统核医学成像的统计质量受限于通过低效传统孔径收集的小信号。编码孔径成像通过采用两步过程克服了这一问题，在该过程中，首先将物体有效地检测为一种与物体本身不同的“编码”形式，然后进行滤波（或“解码”）以形成图像。我们在此展示一类时间调制编码孔径的成像特性，这类编码孔径与大多数编码孔径不同，它编码的是物体的投影而非物体本身。这些编码孔径可以非断层地、断层地（聚焦于一个平面）或三维地重建体物体。我们描述了一种从物体的平面投影重建物体的新解码算法。给出了噪声计算结果，并将这些编码孔径系统的噪声性能与传统对应系统的噪声性能进行了比较。描述了一种结合旋转狭缝和针孔成像优点的混合狭缝 - 针孔系统。提出了一种仅能精确测量事件在一维位置的新型闪烁探测器，并概述了其在我们的编码孔径系统中的应用。最后，给出了对测试物体和动物成像的结果。
