Conversion to dementia in mild cognitive impairment is associated with decline of N-actylaspartate and creatine as revealed by magnetic resonance spectroscopy.

The purpose of the present study was to longitudinally track changes of metabolite markers detectable by magnetic resonance spectroscopy (MRS) in subjects with mild cognitive impairment (MCI) and to analyze these changes with respect to the rate of cognitive decline and clinical disease progression. Fifteen subjects with MCI and 12 healthy elderly controls were investigated longitudinally (average follow-up period: 3.4 years) using absolute quantification of metabolites within the mid-parietal grey matter and the parietal white matter [N-acetylaspartate (NAA), myo-inositol, choline, creatine, glutamine)] Our main findings include that a longitudinal decline in cognitive function (particularly in memory function) within the MCI group was predicted by a decline in absolute concentrations of the metabolic markers NAA and creatine. This effect was mainly explained by a significant decrease of NAA and creatine in those MCI subjects who converted to Alzheimer's dementia (AD) during the follow-up period. No differences were found at baseline between MCI converters and stable subjects, indicating that at least in the present study MRS did provide a predictive discrimination between converters and stable subjects. Our findings support the use of MRS as a tool for objectively monitoring disease progression even during the earliest stages of AD.

Non-invasive measurement of liver and pancreas fibrosis in patients with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis (CF) have a relevant morbidity and mortality caused by CF-related liver-disease. While transient elastography (TE) is an established elastography method in hepatology centers, Acoustic-Radiation-Force-Impulse (ARFI)-Imaging is a novel ultrasound-based elastography method which is integrated in a conventional ultrasound-system. The aim of the present study was to evaluate the prevalence of liver-fibrosis in patients with CF using TE, ARFI-imaging and fibrosis blood tests. METHODS: 106 patients with CF were prospectively included in the present study and received ARFI-imaging of the left and right liver-lobe, ARFI of the pancreas TE of the liver and laboratory evaluation. RESULTS: The prevalence of liver-fibrosis according to recently published best practice guidelines for CFLD was 22.6%. Prevalence of significant liver-fibrosis assessed by TE, ARFI-right-liver-lobe, ARFI-left-liver-lobe, Fibrotest, Fibrotest-corrected-by-haptoglobin was 17%, 24%, 40%, 7%, and 16%, respectively. The best agreement was found for TE, ARFI-right-liver-lobe and Fibrotest-corrected-by-haptoglobin. Patients with pancreatic-insufficiency had significantly lower pancreas-ARFI-values as compared to patients without. CONCLUSIONS: ARFI-imaging and TE seem to be promising non-invasive methods for detection of liver-fibrosis in patients with CF.