Medicine and Health Sciences Commons^™

Chronic Obstructive Pulmonary Disease: Quantification Of Bronchodilator Effects By Using Hyperpolarized ³He Mr Imaging, Miranda Kirby, Lindsay Mathew, Mohammadreza Heydarian, Roya Etemad-Rezai, David G Mccormack, Grace Parraga

Medical Biophysics Publications

PURPOSE: To evaluate short-acting bronchodilator effects in chronic obstructive pulmonary disease (COPD) by using hyperpolarized helium 3 (³He) magnetic resonance (MR) imaging, spirometry, and plethysmography.

MATERIALS AND METHODS: Fourteen ex-smokers with COPD provided written informed consent to a local ethics board-approved and Health Insurance and Portability Accountability Act-compliant protocol and underwent hyperpolarized ³He and hydrogen 1 MR imaging, spirometry, and plethysmography before and a mean of 25 minutes ± 2 (standard deviation) after administration of 400 μg salbutamol. Distribution of ³He gas was evaluated by using semiautomated segmentation of ³He voxel intensities, where cluster 1 represented regions of signal void …

The Effect Of Dopamine Therapy On Ventral And Dorsal Striatum-Mediated Cognition In Parkinson's Disease: Support From Functional Mri., Penny A Macdonald, Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Hooman Ganjavi, Jean-Sebastien Provost, Oury Monchi

Brain and Mind Institute Researchers' Publications

The central aim of our study was to elucidate functions mediated by the ventral and dorsal striatum, respectively, to better understand the cognitive effects of dopamine replacement in Parkinson's disease. We proposed that the ventral striatum underlies general learning of stimulus associations, whereas the dorsal striatum promotes integration of various influences on selecting. In Parkinson's disease, dopamine depletion is substantially less notable in the ventral relative to the dorsal striatum, and therefore greater improvements are expected for dorsal striatum-mediated functions with dopamine replacement. Using a simple selection task, we found that dopamine replacement impaired encoding and facilitation of consistent stimulus-stimulus …

Negative Associations Between Corpus Callosum Midsagittal Area And Iq In A Representative Sample Of Healthy Children And Adolescents., Hooman Ganjavi, John D Lewis, Pierre Bellec, Penny A Macdonald, Deborah P Waber, Alan C Evans, Sherif Karama, The Brain Development Cooperative Group

Brain and Mind Institute Researchers' Publications

Documented associations between corpus callosum size and cognitive ability have heretofore been inconsistent potentially owing to differences in sample characteristics, differing methodologies in measuring CC size, or the use of absolute versus relative measures. We investigated the relationship between CC size and intelligence quotient (IQ) in the NIH MRI Study of Normal Brain Development sample, a large cohort of healthy children and adolescents (aged six to 18, n = 198) recruited to be representative of the US population. CC midsagittal area was measured using an automated system that partitioned the CC into 25 subregions. IQ was measured using the Wechsler …