@article{oai:repo.qst.go.jp:00047987,
 author = {Ahmed, Abdella and Tashima, Hideaki and Yoshida, Eiji and Nishikido, Fumihiko and Yamaya, Taiga and Ａｈｍｅｄ Ａｂｄｅｌｌａ Ｍｏｈａｍｍｅｄｎｕｒ and 田島 英朗 and 吉田 英治 and 錦戸 文彦 and 山谷 泰賀},
 journal = {Physics in Medicine & Biology},
 month = {May},
 note = {There is a growing interest in developing brain PET scanners with high
sensitivity and high spatial resolution for early diagnosis of neurodegenerative
diseases and studies of brain functions. Sensitivity of the PET scanner can be
improved by increasing the solid angle. However, conventional PET scanners
are designed based on a cylindrical geometry, which may not be the most
efficient design for brain imaging in terms of the balance between sensitivity
and cost. We proposed a dedicated brain PET scanner based on a hemispheric
shape detector and a chin detector (referred to as the helmet-chin PET), which
is designed to maximize the solid angle by increasing the number of linesof-
response in the hemisphere. The parallax error, which PET scanners with
a large solid angle tend to have, can be suppressed by the use of depth-ofinteraction
detectors. In this study, we carry out a realistic evaluation of the
helmet-chin PET using Monte Carlo simulation based on the 4-layer GSO
detector which consists of a 16 × 16 × 4 array of crystals with dimensions
of 2.8 × 2.8 × 7.5 mm3. The purpose of this simulation is to show the gain in
imaging performance of the helmet-chin PET compared with the cylindrical
PET using the same number of detectors in each configuration. The sensitivity
of the helmet-chin PET evaluated with a cylindrical phantom has a significant
increase, especially at the top of the (field-of-view) FOV. The peak-NECR
of the helmet-chin PET is 1.4 times higher compared to the cylindrical PET.
The helmet-chin PET provides relatively low noise images throughout the
FOV compared to the cylindrical PET which exhibits enhanced noise at the
peripheral regions. The results show the helmet-chin PET can significantly
improve the sensitivity and reduce the noise in the reconstructed images.},
 pages = {4541--4550},
 title = {Simulation study comparing the helmet-chin PET with a cylindrical PET of the same number of detectors},
 volume = {62},
 year = {2017}
}