Y. Yuan's research while affiliated with Fudan University and other places

Objective To investigate the characteristics of cerebral blood perfusion in the patients with mild cognitive impairment (MCI) by comparing to normal controls and to evaluate the potential roles of SPECT in identifying subjects with MCI from normal aging. Methods Twenty patients, who were diagnosed as having MCI, and 20 normal aging subjects each underwent a 99 mTc-ethylcysteinate dime SPECT cerebral blood perfusion imaging. SPECT images were processed with SPM5b software and performed a voxel-based statistical analysis comparing MCI patients and normal aging subjects. Results In comparison with normal controls, subjects with MCI showed asymmetry hypoperfusion in the posterior cingulate gyrus, inferior and superior parietal lobule, cingulate gyrus, inferior and superior frontal gyrus. Conclusion Hypoperfusion is detected in reletively specific region in the patients with MCI and the clinical use of cerebral blood perfusion imaging for the detection of MCI is promising.

Patients with mild cognitive impairment (MCI) are at risk for developing Alzheimer disease (AD). To diagnose AD at an early stage, one must develop highly specific and sensitive tools to identify it among at-risk subjects. The purpose of this study was to evaluate and compare the ability of fluorodeoxyglucose-positron-emission tomography (FDG-PET), single-photon emission tomography (SPECT), and structural MR imaging to predict conversion to AD in patients with MCI. Relevant studies were identified with MEDLINE from January 1990 to April 2008. Meta-analysis and meta-regression were done on the diagnostic performance data for each technique from eligible studies. We estimated and compared the weighted summary sensitivities, specificities, likelihood ratios (LRs), and summary receiver operating characteristic curves of each imaging technique. Twenty-four eligible studies were included, with a total of 1112 patients. FDG-PET performed statistically better in LR+ and odds ratio (OR), whereas no statistical difference was found in pooled sensitivity, specificity, and LR- for each technique. No statistical difference was confirmed between SPECT and MR imaging. The Q* index estimates for FDG-PET, SPECT, and structural MR imaging were respectively 0.86, 0.75, and 0.76. In meta-regression, statistical significance was found only between technique and log OR, with a regression coefficient of -0.575. This meta-analysis showed that FDG-PET performs slightly better than SPECT and structural MR imaging in the prediction of conversion to AD in patients with MCI; parallel performance was found between SPECT and MR imaging.

Objective: To investigate the clinical value of radionuclide bone scanning for detecting bone metastasis in elderly patients with lung cancer. Methods: All the elderly patients with lung cancer underwent planar whole-body scans after injection of 99mTc-MDP. To those 35 patients detected singular lesion in planar scans, SPECT imaging of the impaired spine was performed afterwards at the same day. Results: (1) Skeletal metastases were verified in 74 patients (23.3%). More metastases were detected in thoracic region and vertebral column (P<0.05). (2) The incidence of bone metastasis was also varying with different histopathological types of cancer. The bone metastasis was more common in patients with adenocarcinoma (P<0.05). (3) Among 112 patients underwent more than twice of bone scans, 19 of them were detected skeletal metastases during that period of time. (4) As for the period of disease, significantly more patients were verified skeletal metastases during their first 3 months. Conclusion: Radionuclide bone imaging is significant for staging, selecting therapy methods and evaluating the prognosis of lung cancer.