Although molecular positron emission tomography imaging of amyloid and tau proteins can facilitate the detection of preclinical Alzheimer’s disease (AD) pathology, it is not useful in clinical practice. More practical surrogate markers for preclinical AD would provide valuable tools. Thus, we sought to validate the utility of conventional magnetic resonance spectroscopy (MRS) as a screening method for preclinical AD. A total of 289 older participants who were cognitively normal at baseline were clinically followed up for analysis of MRS metabolites, including N-acetyl aspartate (NAA) and myo-inositol (MI) in the posterior cingulate cortex (PCC) for 7 years. The 289 participants were retrospectively divided into five groups 7 years after baseline: 200 (69%) remained cognitively normal; 53 (18%) developed mild cognitive impairment (MCI); 21 (7%) developed AD; eight (2%) developed Parkinson’s disease with normal cognition, and seven (2%) developed dementia with Lewy bodies (DLB). The NAA/MI ratios of the PCC in the AD, MCI, and DLB groups were significantly decreased compared with participants who maintained normal cognition from baseline to 7 years after baseline. MMSE scores 7 years after baseline were significantly correlated with MI/Cr and NAA/MI ratios in the PCC. These results suggest that cognitively normal elderly subjects with low NAA/MI ratios in the PCC might be at risk of progression to clinical AD. Thus, the NAA/MI ratio in the PCC measured with conventional 1H MRS should be reconsidered as a possible adjunctive screening marker of preclinical AD in clinical practice.

No abstract

The purpose of this study was to investigate the difference of coronary artery disease (CAD) severity and extent as well as plaque characteristics between patients with either one of hypertension (HT), diabetes mellitus (DM) or dyslipidemia (DL). We retrospectively reviewed the records of 1,161 patients (HT 442, DM 77, DL 248, no disease 394) who underwent coronary computed tomography angiography. Stenosis severity was classified as normal, non-obstructive (1-49 % stenosis), moderate (50-69 % stenosis) or severe (≥70 % stenosis). Segment involvement score (SIS) and segment severity score (SSS) was calculated. We defined patients at risk as patients with obstructive CAD or non-obstructive CAD with extensive disease (SIS ≥ 5). Plaque characteristics were evaluated including positive remodeling, low attenuation and spotty calcification. Obstructive CAD was most frequent in DM patients, followed by HT and DL patients (34, 19 and 15 %, respectively, p < 0.0001). DM patients had more extensive disease than HT and DL patients (SIS 3.1 vs 2.1 vs 1.4, SSS 4.0 vs 2.7 vs 2.0). DM patients were more at risk than HT and DL patients (p < 0.05). The prevalence of positive remodeling, low attenuation and spotty calcium were all highest in DM patients (p < 0.005, vs HT and DL), while low attenuation was more frequent in DL than HT patients (p < 0.005). The median calcium score of HT and DM patients were higher than DL patients (p < 0.01 and p < 0.005, respectively), while no significant difference was observed between HT and DM patients. In conclusion, DM patients possessed more high risk plaque and obstructive as well as extensive CAD compared with HT and DL patients. Coronary calcification was similarly high in HT and DM patients. Low attenuation plaque was more frequent in DL than HT patients.

For 50-year-old patients, treatment of aneurysms that are small (<7 mm), that are located in the cavernous carotid artery, or that are large (>or=25 mm) and located in the posterior circulation is ineffective or not cost-effective.