Naoaki Tanizaki, Presenter: Nothing to Disclose

Keizo Ishii, Abstract Co-Author: Nothing to Disclose

Daizo Amano, Abstract Co-Author: Nothing to Disclose

Manabu Yamada, Abstract Co-Author: Nothing to Disclose

Hiromichi Yamazaki, Abstract Co-Author: Nothing to Disclose

Takashi Yamaguchi, Abstract Co-Author: Nothing to Disclose

Takashi Yano, Abstract Co-Author: Nothing to Disclose

Akihiko Taneda, Abstract Co-Author: Nothing to Disclose

Toshio Monzen, Abstract Co-Author: Nothing to Disclose

Shigeo Matsuyama, Abstract Co-Author: Nothing to Disclose

Youhei Kikuchi, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Our goal of this development is to realize a PET scanner which has an ultra high spatial resolution of less than 1mm in FWHM. To realize that, we use a cadmium telluride (CdTe) for detectors, which is a compound semiconductor. To demonstrate the spatial resolution, we have developed an experimental scanner. The scanner is a practical scanner for small animal studies. The purpose of this study is to confirm the spatial resolution of less than 1mm using the scanner.

To realize the spatial resolution, we designed the size of a detector as, 1.1mm width, 1.0mm height and 5mm long. To make a detector ring, we have developed a detector module which consists of 512 detectors. The size of a detector module is, 19.7mm width, 27mm height and 10mm long. A detector ring consists of 16 modules. The ring diameter is 114mm. The axial FOV is 27mm and transaxial FOV is 77mm. Voxel size of a reconstructed image is 0.15mm in transaxial and 0.85mm in axial. Each detector is connected to an individual readout electronics. And they are connected to FPGA boards which add the time stump of each gamma-ray event. The boards are connected to a data acquisition computer which makes coincidence data. The data acquisition computer is connected to image processing computer which makes an image reconstruction.

We examined a thin tube phantom study, which inner diameter of tube is 0.25mm. As the result, we have measured the spatial resolution as 0.8mm in FWHM at the center of the FOV. And we made a multi tube phantom study, which inner diameter of tubes are 0.5mm. The distances between tubes are from 1.0mm to 2.5mm. As the result, we could clearly discriminate all the hot spots. All images are reconstructed by 2D-FBP algorithm.

We could successfully confirm a spatial resolution of less than 1mm in FWHM with a good image quality in the FOV. After evaluating other performances and studying of animals, we will develop a dedicated small animal PET scanner.

In PET study, ultra high spatial resolution of less than 1mm in FWHM can demonstrate small cancers and neurological functions in the brain.

Tanizaki, N, Ishii, K, Amano, D, Yamada, M, Yamazaki, H, Yamaguchi, T, Yano, T, Taneda, A, Monzen, T, Matsuyama, S, Kikuchi, Y, et al, , et al, , Development of an Ultra High Spatial Resolution PET Scanner Using CdTe Detector.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5009886.html