Detection of early CT sign and dose reduction using stochastic resonance

2016 Fiscal Year Final Research Report

• Project/Area Number: 26461821
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Radiation science
• Research Institution: Nagoya University
• Principal Investigator: Imai Kuniharu 名古屋大学, 医学系研究科(保健), 教授 (20335053)
• Co-Investigator(Renkei-kenkyūsha): KAWAURA CHIYO 名古屋大学, 医学部, 講師 (60324422) ; FUJII KEISUKE 名古屋大学, 医学部, 助教 (40469937)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 確率共鳴 / 確率同期 / 画質 / CT / 情報量解析 / コントラスト分解能

Outline of Final Research Achievements

Image noise in CT images is one of the major factors degrading the image quality. Thus, many studies of noise reduction techniques have been conducted. On the contrary, the phenomenon that disproves such traditional thought for noise has been discovered and is called “stochastic resonance”. It is known that this phenomenon appears by adding white Gaussian noise to non-linear system and provides the improvement of the system response. Thus, this phenomenon can be applied for improving signal detectability in CT images. From these viewpoints, we have set out on the following two subjects of study; 1) CNR analysis of noise-added CT images 2) Entropy analysis of noise-added CT images.
This study showed that stochastic resonance and stochastic synchronization appeared in CT images when white Gaussian noise and band-limited noise in spatial frequency domain was added. Consequently, the contrast resolution and sharpness of CT images was improved.

Free Research Field

物性工学、情報工学