No abstract

The objective of this study was to assess whether reduced glucose metabolism (rCMRGlu) and cognitive functioning could predict development of Alzheimer's disease (AD) in subjects with mild cognitive impairment (MCI). Twenty MCI patients underwent baseline and follow-up investigations of rCMRGlu, as measured by PET, and cognitive function measured by neuropsychological test assessments. Subjects were clinically followed up with an average interval of 36.5 months. Two groups were obtained after the second clinical assessment. Nine patients were diagnosed as AD and classified as progressive MCI (P-MCI), whereas 11 patients remained clinically stable and were classified as stable MCI (S-MCI). There were no differences in demographic variables or baseline MMSE between the two subgroups. Logistic regression indicated the two variables that most effectively predicted future development of AD were rCMRGlu from the left temporoparietal area and performance on the block design. These combined measures gave an optimal 90% correct classification rate, whereas only rCMRGlu or neuropsychology alone gave 75% and 65% correct classification, respectively. Measures of temporoparietal cerebral metabolism and visuospatial function may aid in predicting the evolution to AD for patients with MCI.

This report provides a compendium of current information relating to radiation dose to patients, including biokinetic models, biokinetic data, dose coefficients for organ and tissue absorbed doses, and effective dose for major radiopharmaceuticals based on the radiation protection guidance given in Publication 60(ICRP, 1991). These data were mainly compiled from Publications 53, 80, and 106(ICRP, 1987, 1998, 2008), and related amendments and corrections. This report also includes new information for 82Rb-chloride, iodide (123I, 124I, 125I, and 131I) and 123I labeled 2ß-carbomethoxy 3ß-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FPCIT).The coefficients tabulated in this publication will be superseded in due course by values calculated using new International Commission on Radiation Units and Measurements/International Commission on Radiological Protection adult and paediatric reference phantoms and Publication 103 methodology (ICRP,2007). The data presented in this report are intended for diagnostic nuclear medicine and not for therapeutic applications.

The forced oscillation technique makes it possible to evaluate the mechanical properties of the respiratory system with a minimum of cooperation. The method is therefore especially useful in children. Impulse oscillometry (IOS) is a commercially available version of this technique. There is, as yet, limited information on reference values for IOS in children. The aim of this study was to extend the reference values for IOS variables and to study their correlation with height, weight and age in healthy children. A sample (n = 360) of children (age 2.1-11.1 years) was measured by using impulse oscillometry (IOS; Jaeger, Würzburg, Germany). The sample was based on children attending kindergarten in Finland and children attending primary school in Sweden. Measurements of respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, 15 and 20 Hz, total respiratory impedance (Zrs) and the resonance frequency (Fr) were made. All variables were related to body height. Most of them were also weakly related to weight. Reference equations for children (height 90-160 cm) are presented.

Intracerebral microdialysis (MD) was applied in patients with subarachnoid hemorrhage. The regional CBF, the CMRO2, and oxygen extraction ratio (OER) were measured with simultaneous positron emission tomography (PET). The aim was to directly correlate alterations in dialysate levels of energy-related metabolites (lactate, lactate/pyruvate ratio, hypoxanthine) and excitatory amino acids (EAAs) (glutamate and aspartate) to the energy state in the MD probe region as determined by PET. Regional ischemia was defined according to Heiss et al. and Lassen (Heiss et al., 1992; Lassen, 1966). Whole-brain ischemia was considered present when the OER for the whole brain exceeded the mean whole-brain OER + 2 SD of six reference patients. In general, the presence of whole-brain ischemia and/or regional ischemia within the region of the MD probe was associated with increased levels of energy-related metabolites and EAAs retrieved by MD. Increased levels of energy-related metabolites and EAAs were only occasionally seen when PET did not show any signs of ischemia or when signs of regional ischemia were found remote from the MD probe region. Thus, the energy-related metabolites and EAAs may be used as extracellular "markers" of ischemia. PET may be of use in defining critical ischemic regions (tissue at risk) where the MD probe can be inserted for chemical monitoring.