Comparison of Alzheimer's disease patients and healthy controls in the easy Z-score imaging system with differential image reconstruction methods using SPECT/CT: verification using normal database of our institution

Makoto Ohba; Ryota Kobayashi; Kazukuni Kirii; Kyosuke Fujita; Chika Kanezawa; Hiroshi Hayashi; Shinobu Kawakatsu; Koichi Otani; Masafumi Kanoto; Koji Suzuki

doi:10.1007/s12149-020-01562-8

Comparison of Alzheimer's disease patients and healthy controls in the easy Z-score imaging system with differential image reconstruction methods using SPECT/CT: verification using normal database of our institution

Ann Nucl Med. 2021 Mar;35(3):307-313. doi: 10.1007/s12149-020-01562-8. Epub 2021 Jan 4.

Authors

Affiliations

¹ Department of Radiology, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan. m-ohba@med.id.yamagata-u.ac.jp.
² Department of Psychiatry, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
³ Division of Diagnostic Radiology, Department of Radiology, Yamagata University Faculty of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
⁴ Department of Radiology, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
⁵ Department of Neuropsychiatry, Aizu Medical Center, Fukushima Medical University, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.

PMID: 33394329
DOI: 10.1007/s12149-020-01562-8

Abstract

Objective: The easy Z-score imaging system (eZIS) analysis is used for the diagnosis of dementia by cerebral blood flow on single photon emission computed tomography (SPECT). Differences in the acquisition and reconstruction conditions in SPECT may affect the eZIS analysis results. The present study aimed to construct our institutional normal database (NDB) and Alzheimer's disease (AD)-specific volumes of interest (VOIs) in eZIS analysis, and to compare the differential diagnostic ability between healthy controls (HC) and patients with AD in the image reconstruction filtered back projection (FBP) and ordered subset expectation maximization (OSEM) methods.

Methods: An NDB was constructed at our institution from 30 healthy individual using the FBP and OSEM reconstruction methods. We divided 51 HC and 51 AD patients into two groups, one for AD disease-specific VOI construction (HC, AD) and the other for NDB verification (HC, AD); image reconstruction was performed using FBP and OSEM. The areas of reduced blood flow in AD patients were compared with those of HC using the two types of image reconstruction methods. We used AD disease-specific VOI and NDB from each reconstruction method in eZIS analysis and compared the differential diagnostic ability for HC and AD with the different reconstruction methods.

Results: Comparing the areas of reduced blood flow in AD patients using the different image reconstruction methods, OSEM showed decreased blood flow in the medial region of the temporal lobes compared to FBP. Comparing the differential diagnostic ability for HC and AD using eZIS, the Severity, Extent, and Ratio showed higher values in the analysis performed using OSEM image reconstruction compared to FBP.

Conclusion: With the ^99mTc-ECD SPECT, the eZIS analysis equipped with our institutional AD-specific VOI and NDB using OSEM image reconstruction could distinguish HC from AD better than eZIS analysis using FBP image reconstruction. This study is registered in UMIN Clinical Trials Registry (UMIN-CTR) as UMIN study ID: UMIN000042362.

Keywords: Alzheimer’s disease; Cerebral blood flow; Easy Z-score imaging system; Ordered subset expectation maximization method; Single photon emission computed tomography.

Publication types

Comparative Study

MeSH terms

Aged
Alzheimer Disease / diagnostic imaging*
Case-Control Studies
Databases, Factual*
Female
Humans
Image Processing, Computer-Assisted / methods*
Male
Single Photon Emission Computed Tomography Computed Tomography*