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Systematic review and meta-analysis of diagnostic test accuracy (DTA) studies: the role of cerebral perfusion imaging in prognosis evaluation of mild cognitive impairment.

BACKGROUND
The application value of cerebral perfusion imaging, such as fluorodeoxyglucose-positron-emission computed tomography (FDG-PET), single-photon emission computed tomography (SPECT), and structural magnetic resonance imaging (MRI), in the prognostic assessment of mild cognitive impairment (MCI) remains unclear. Thus, it was the focus of this meta-analysis, which aimed to provide a theoretical basis for early diagnosis of neurological diseases.


METHODS
The Boolean logic retrieval method was used to retrieve related literature, with "cognitive disorder", "cerebral perfusion imaging", "cerebral imaging", "mild cognitive impairment", and "prognostic assessment" as search terms. The PubMed, Medline, CNKI (China National Knowledge Infrastructure), and other databases were searched from the date of establishment of the database to December 30, 2020 for literature on the prognostic assessment of MCI using FDG-PET, SPECT, and MRI imaging. Meta-analysis was performed using Review Manager software.


RESULTS
A total of 16 references were identified, most of which had a low risk of bias (i.e. medium and high-quality). The meta-analysis results showed that the sensitivity and specificity of FDG-PET imaging was significantly higher than those of SPECT and MRI imaging, and the differences were statistically significant (P<0.05). The summary receiver operating characteristic (sROC) curves for the sensitivity and specificity of FDG-PET, SPECT, and MRI imaging did not present a "shoulder arm" distribution, and there was no threshold effect.


DISCUSSION
Cerebral perfusion imaging has good prognostic value for patients with MCI, and FDG-PET imaging has better predictive ability of the prognosis for patients with MCI.