1 Department of Radiology, Mayo Clinic, CT Clinical Innovation Center, 200 First St SW, East 2 Mayo Bldg, Rochester, MN 55905.
AJR Am J Roentgenol. 2013 Oct;201(4):W626-32. doi: 10.2214/AJR.12.10234.
The objective of our study was to evaluate in phantoms the differences in CT image noise and artifact level between two types of commercial CT detectors: one with distributed electronics (conventional) and one with integrated electronics intended to decrease system electronic noise.
Cylindric water phantoms of 20, 30, and 40 cm in diameter were scanned using two CT scanners, one equipped with integrated detector electronics and one with distributed detector electronics. All other scanning parameters were identical. Scans were acquired at four tube potentials and 10 tube currents. Semianthropomorphic phantoms were scanned to mimic the shoulder and abdominal regions. Images of two patients were also selected to show the clinical values of the integrated detector.
Reduction of image noise with the integrated detector depended on phantom size, tube potential, and tube current. Scans that had low detected signal had the greatest reductions in noise, up to 40% for a 30-cm phantom scanned using 80 kV. This noise reduction translated into up to 50% in dose reduction to achieve equivalent image noise. Streak artifacts through regions of high attenuation were reduced by up to 45% on scans obtained using the integrated detector. Patient images also showed superior image quality for the integrated detector.
For the same applied radiation level, the use of integrated electronics in a CT detector showed a substantially reduced level of electronic noise, resulting in reductions in image noise and artifacts, compared with detectors having distributed electronics.
本研究旨在体模中评估两种类型的商用 CT 探测器的 CT 图像噪声和伪影水平差异：一种是具有分布式电子设备的（常规），另一种是具有集成电子设备以降低系统电子噪声的。
使用两种 CT 扫描仪对直径为 20、30 和 40cm 的圆柱形水模进行扫描，一种配备集成探测器电子设备，另一种配备分布式探测器电子设备。所有其他扫描参数均相同。在四个管电压和 10 个管电流下采集扫描。半人体模型体模用于模拟肩部和腹部区域。还选择了两个患者的图像以显示集成探测器的临床价值。
使用集成探测器降低图像噪声取决于体模大小、管电压和管电流。具有低检测信号的扫描具有最大的噪声降低，对于使用 80kV 扫描的 30cm 体模，噪声降低可达 40%。这种噪声降低可转化为高达 50%的剂量降低，以达到等效的图像噪声。在使用集成探测器获得的扫描中，通过高衰减区域的条纹伪影减少了高达 45%。患者图像也显示了集成探测器的卓越图像质量。
对于相同的应用辐射水平，与具有分布式电子设备的探测器相比，在 CT 探测器中使用集成电子设备可显著降低电子噪声水平，从而降低图像噪声和伪影水平。
