Noelpp U B, Roesler H, Ritter E P, Ledermann H
Department of Nuclear Medicine, University of Berne, Inselspital, Switzerland.
J Comput Assist Tomogr. 1994 Jan-Feb;18(1):102-9. doi: 10.1097/00004728-199401000-00022.
Seven pinhole tomography (SPHT) is fast, inexpensive, and, because it relies on standard gamma cameras and computers, available everywhere. This article investigates the suitability of SPHT for the detection and localization of 511 keV gammas emitted from 18F without coincidence detection.
A standard SPH collimator and the table were additionally shielded with lead. For comparison, point sources and cardiac phantoms were imaged on SPHT and a triple head gamma camera (THC). The phantom studies were supplemented with patient examinations using a standard clinical protocol. Circumferential profiles allowed a direct comparison of perfusion under different conditions or perfusion plus metabolism.
Dedicated for cardiac workup, SPHT has a 5-10 times better sensitivity (dependent on distance) than THC and gives superior resolution for the extension of a lesion perpendicular to the long cardiac axis: The full width at half-maximum for x- and y-directions (FWHMx,y) for a 99mTc-point source was found to be 35 and 22% smaller at 130 and 220 mm distances with SPHT than with THC. The SPHT even surpasses the THC at greater distances. The resolution falls off with 18F: FWHM increases by 70 and 48%, respectively, compared to 99mTc. The in-depth resolution is worse with SPHT: The FWHM (using 99mTc) is 2-3.5 times greater with SPHT than with THC and remains within this range with 18F.
It is possible to image 18F distributions using SPHT with a very high sensitivity and good detail resolution, even in the presence of 99mTc and 201Tl. The SPHT compares well with THC for 99mTc, except in its in-depth resolution, and is unsurpassed in its sensitivity and ease of performance.
七针孔断层扫描（SPHT）速度快、成本低，并且由于它依赖于标准伽马相机和计算机，所以在任何地方都可使用。本文研究了在不进行符合探测的情况下，SPHT用于检测和定位18F发射的511 keV伽马射线的适用性。
用铅对标准SPH准直器和检查台进行额外屏蔽。为作比较，在SPHT和三头伽马相机（THC）上对点状源和心脏模型进行成像。使用标准临床方案对患者进行检查，以补充模型研究。圆周剖面图能直接比较不同条件下的灌注情况或灌注加代谢情况。
专为心脏检查设计的SPHT，其灵敏度比THC高5至10倍（取决于距离），并且在垂直于心脏长轴方向上对病变范围的分辨率更高：对于99mTc点状源，在距离为130和220 mm时，SPHT在x和y方向上的半高宽（FWHMx,y）比THC分别小35%和22%。在更大距离时，SPHT甚至超过了THC。使用18F时分辨率下降：与99mTc相比，FWHM分别增加了70%和48%。SPHT的深度分辨率较差：使用99mTc时，SPHT的FWHM比THC大2至3.5倍，使用18F时仍在此范围内。
即使存在99mTc和201Tl，也可以使用SPHT以非常高的灵敏度和良好的细节分辨率对18F分布进行成像。对于99mTc，SPHT除深度分辨率外，与THC相比表现良好，并且在灵敏度和操作简便性方面无与伦比。
