Central Research Laboratory, Hitachi Ltd., Hitachi-shi, Ibaraki-ken, Japan.
Phys Med Biol. 2013 Nov 7;58(21):7715-31. doi: 10.1088/0031-9155/58/21/7715. Epub 2013 Oct 18.
For high-sensitivity brain imaging, we have developed a two-head single-photon emission computed tomography (SPECT) system using a CdTe semiconductor detector and 4-pixel matched collimator (4-PMC). The term, '4-PMC' indicates that the collimator hole size is matched to a 2 × 2 array of detector pixels. By contrast, a 1-pixel matched collimator (1-PMC) is defined as a collimator whose hole size is matched to one detector pixel. The performance of the higher-sensitivity 4-PMC was experimentally compared with that of the 1-PMC. The sensitivities of the 1-PMC and 4-PMC were 70 cps/MBq/head and 220 cps/MBq/head, respectively. The SPECT system using the 4-PMC provides superior image resolution in cold and hot rods phantom with the same activity and scan time to that of the 1-PMC. In addition, with half the usual scan time the 4-PMC provides comparable image quality to that of the 1-PMC. Furthermore, (99m)Tc-ECD brain perfusion images of healthy volunteers obtained using the 4-PMC demonstrated acceptable image quality for clinical diagnosis. In conclusion, our CdTe SPECT system equipped with the higher-sensitivity 4-PMC can provide better spatial resolution than the 1-PMC either in half the imaging time with the same administered activity, or alternatively, in the same imaging time with half the activity.
为了进行高灵敏度脑部成像，我们开发了一种使用碲化镉半导体探测器和 4 像素匹配准直器（4-PMC）的双头单光子发射计算机断层扫描（SPECT）系统。术语“4-PMC”表示准直器孔的尺寸与探测器像素的 2×2 阵列相匹配。相比之下，1 像素匹配准直器（1-PMC）被定义为孔的尺寸与一个探测器像素相匹配的准直器。实验比较了更高灵敏度的 4-PMC 与 1-PMC 的性能。1-PMC 和 4-PMC 的灵敏度分别为 70 cps/MBq/head 和 220 cps/MBq/head。使用 4-PMC 的 SPECT 系统在相同的活动和扫描时间下，与 1-PMC 相比，在冷棒和热棒体模中提供了更好的图像分辨率。此外，在扫描时间减半的情况下，4-PMC 提供了与 1-PMC 相当的图像质量。此外，使用 4-PMC 对健康志愿者进行的 (99m)Tc-ECD 脑灌注图像显示，对于临床诊断，图像质量可接受。总之，我们配备了更高灵敏度的 4-PMC 的碲化镉 SPECT 系统可以提供比 1-PMC 更好的空间分辨率，无论是在相同的给药活动下减半的成像时间，还是在相同的成像时间下减半的活动。
