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Assessment of beta‐amyloid deposition using gray matter delineation by early‐phase F‐18 florbetaben PET in patients with brain atrophy
Author(s) -
Jeong Shin Young,
Yoon Uicheul,
Kang Kyunghun,
Lee SangWoo
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.038717
Subject(s) - nuclear medicine , medicine , intraclass correlation , concordance , concordance correlation coefficient , atrophy , white matter , confidence interval , correlation , magnetic resonance imaging , pathology , radiology , mathematics , statistics , clinical psychology , geometry , psychometrics
Background In patients with brain atrophy, it can be difficult to distinguish between pathologic amyloid accumulation of gray matter and nonspecific uptake of white matter in F‐18 florbetaben (FBB) PET. We evaluated gray matter edges delineation method derived from the perfusion phase of FBB PET (GM_eFBB) and investigated whether standard visual diagnosis (STD) can be improved the confidence level and concordance rate when we used STD combined GM_eFBB in patients with idiopathic normal pressure hydrocephalus (iNPH). Method Two‐phase FBB PET and brain MRI were performed in 42 iNPH patients with subjective cognitive impairment. Gray matter delineation using each individual’s brain MRI (GM_MR) was performed and a cut‐off value of SUVR was evaluated to find the GM_eFBB closest to GM_MR. Two nuclear medicine physicians blindly and independently evaluated all late‐phase FBB images, initially employing the STD method and later the STD combined GM_eFBB method. Binary classification (positive/negative) and subjective confidence (three‐point scale) of diagnosis were evaluated. A Pearson correlation coefficient (PCC) between GM_eFBB and GM_MR was determined, and the Wilcoxon signed‐rank test was used to evaluate differences in subjective confidence between two methods. Intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC) were determined for two methods. Result The GM_eFBB obtained by cut‐off value that determined as 50% of the peak SUVR was closest to the GM_MR. PCC was greater than 0.97 for all lobes (p<0.0001). The STD combined GM_eFBB method resulted in significantly greater subjective confidence in the readings (p = 0.027). The CCC for the STD method was 0.65, and for the STD combined GM_eFBB method was 0.73. The ICC was higher for the STD combined GM_eFBB method (0.73, 95%CI 0.56–0.85) than for the STD method (0.65, 95% CI 0.44–0.79). The binary classification was concordant in 83.3% of the scans using the STD method and in 88.1% of the scans using the STD combined GM_eFBB method. Conclusion The STD combined GM_eFBB method can facilitate assessment of beta‐amyloid deposition in gray matter in patients with iNPH. The method may be applicable to patient with brain atrophy who may be difficult to judge of beta‐amyloid presence in gray matter.