Manus Donahue^1,2, Erin Hussey³, Tracy Porchak¹, Swati Rane¹, Matthias van Osch⁴, Nolan Hartkamp⁵, Jeroen Hendrikse⁵, and Brandon Ally^2,3
1Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States, ²Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, United States, ³Neurology, Vanderbilt University School of Medicine, Nashville, TN, United States, ⁴Radiology, Leiden University, Leiden, Netherlands, ⁵Radiology, University Medical Center Utrecht, Utrecht, Netherlands

The overall aim of this work is to apply a novel, planning-free regional perfusion imaging (RPI) approach in patients with varying cognitive impairment to better understand the relationship between flow territory asymmetry, cognitive performance, and dementia risk. Average (n=20) flow-territory maps demonstrate high symmetry within the vertebrobasilar flow territory, and between right and left middle cerebral artery flow territories; however, volunteers with lower cognitive scores demonstrated increased flow territory asymmetry (P<0.05). These results demonstrate the first planning-free application of RPI in patients with cognitive impairment, and furthermore support an association between cognitive performance and asymmetric collateral flow patterns.

Ai-Ling Lin¹, Timothy Q Duong¹, Eric Muir¹, Anuradha Soundararajan¹, Peter T Fox¹, Arlan G Richardson², and Veronica Galvan^2
1Research Imaging Institute, University of Texas Health Science Center at San Anotnio, San Antonio, TX, United States, ²Barshop Institute for Logevity and Aging Studies, University of Texas Health Science Center at San Anotnio, San Antonio, TX, United States

Rapamycin is known to be associated with increased lifespan and delayed aging in mice. Recent studies show that treatment of mice modeling Alzheimer’s disease (AD) (e.g., hAPP(J20)) with rapamycin halts the progression of AD-like memory deficits and reduces Aß accumulation. Here we used multimodal neuroimaging methods (MRI and PET) to investigate the effect of rapamycin on vascular and metabolic functions in hAPP(J20) mice. Our results showed that hAPP (J20) mice had significant vasucular dysfunction (relative to metabolic), especially in the regions involved cognitive function (e.g., hippocampus; memory and learning). Rapamycin treatment restored the vascular function in hippocampus, which may consequently preserve the memory and learning ability of the hAPP (J20) mice.

Gwenaelle Douaud¹, Helga Refsum², Celeste de Jager², Robin Jacoby², Stephen Smith¹, and A. David Smith^2
1FMRIB Centre, University of Oxford, Oxford, Oxfordshire, United Kingdom, ²OPTIMA, University of Oxford

We investigated the impact of B vitamin treatment on grey matter (GM) loss over a 2 year period on cognitively impaired elderly. Using FSL-VBM, we found significant loss of GM in placebo and vitamin groups. However, the GM loss was significantly smaller over time in the vitamin group compared to the placebo group in regions vulnerable to the Alzheimer’s disease process and showing marked atrophy in the placebo group. Remarkably, higher levels of plasma homocysteine were associated with significantly increased GM atrophy, but this deleterious effect was compensated for by the B vitamin treatment.

Chunlei Liu^1,2, Wei Li¹, Christian Langkammer³, Reinhold Schmidt³, and Stefan Ropele^3
1Brain Imaging and Analysis Center, Duke University, Durham, NC, United States, ²Department of Radiology, Duke University, Durham, NC, United States, ³Department of Neurology, Medical University of Graz, Graz, Austria

In this study of 126 healthy subjects, magnetic susceptibility of the brain nuclei is found to be highly correlated with a number of cognitive test scores. Of the six anatomical regions analyzed, the globus pallidus and the putamen demonstrated the most significant correlation. For instance, increased susceptibility is shown to be associated with deteriorated motor skill which is particularly relevant to Parkinson’s disease. The red nucleus shows significant correlation with the language functions. If the results are further validated in diseased populations, magnetic susceptibility could be a potential useful quantitative biomarker for certain neurological diseases and cognitive impairment.

Bo Hou¹, Han Wang², Hui YOU¹, and Feng Feng^1
1Department of radiology, Peking Union Medical College Hospital, Beijing, Beijing, China, ²Department of Neurology, Peking Union Medical College Hospital, Beijing, Beijing, China

Relaxation rate is thought to be a sensitive marker to reflect regional degeneration prior to morphological changes, while the available voxel-based relaxometry(VBR) studies on Parkinsonian variant of multiple system atrophy(MSA-P) did not reveal the distribution of abnormal relaxation as voxel-based morphometry (VBM).This study tries to explore this issue with a 3T scanner and a multi-echo GRE sequence. The objective voxel-based method was used for statistical analysis. The result of VBR comparing MSA-P and control matches well with the VBM results, and also revealed corpus callosum involvement which is spared in VBM, confirming a good availability of this method.

Tracy R Melzer^1,2, Richard Watts^1,3, Michael R MacAskill^1,2, Toni L Pitcher^1,2, Leslie Livingston^1,2, Ross J Keenan⁴, John C Dalrymple-Alford^1,5, and Tim J Anderson^1,2
1New Zealand Brain Research Institute, Christchurch, New Zealand, ²University of Otago, Christchurch, New Zealand, ³College of Medicine, University of Vermont, Burlington, VT, United States, ⁴Christchurch Radiology Group, New Zealand, ⁵University of Canterbury, New Zealand

We used structural MRI to characterize grey matter differences associated with cognitive status in Parkinson’s disease (PD). PD patients were classified as cognitively normal (PD-N), with mild cognitive impairment (PD-MCI), or with dementia (PD-D). Those with PD-D exhibited widespread grey matter atrophy relative to healthy individuals, PD-N, and PD-MCI; limited atrophy was identified in PD-MCI. Global cognitive score was significantly associated with regional grey matter loss. The development of dementia in Parkinson’s disease is associated with extensive atrophy, however limited atrophy occurs earlier. Longitudinal follow up will help clarify the utility of structural MRI to predict PD-related cognitive decline.

Federica Agosta¹, Kristina Davidovic¹, Nikola Kresojevic², Lidia Sarro¹, Marina Svetel², Iva Stankovic², Giancarlo Comi³, Vladimir S. Kostic², and Massimo Filippi^1
1Neuroimaging Research Unit, Institute of Experimental Neurology, San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy, Italy, ²Clinic of Neurology, Faculty of Medicine, University of Belgrade, Belgrade, Yugoslavia, ³Department of Neurology, San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy, Italy

In this study, we investigated brain white matter (WM) damage in patients with Parkinson’s disease (PD) carrying mutations in the gene encoding glucocerebrosidase (GBA) compared with idiopathic PD patients, at similar disease stage. GBA mutation PD carriers showed a damage to the genu of the corpus callosum and cingulum. PD patients without GBA mutations did not show significant diffusion tensor MRI abnormalities when compared with healthy controls. Future research will clarify whether WM damage in these patients may have an impact on the clinical phenotype, in particular on the development of cognitive impairment.

Silvia Mangia¹, Andrew Tyan¹, Paul Tuite², Michael Lee³, Michael Garwood¹, and Shalom Michaeli^1
1CMRR - Dept. of Radiology, University of Minnesota, Minneapolis, Minnesota, United States, ²Dept. of Neurology, University of Minnesota, Minneapolis, Minnesota, United States, ³Dept. of Neuroscience, University of Minnesota, Minneapolis, Minnesota, United States

In addition to classic midbrain pathology, Parkinson disease (PD) is accompanied by changes in pontine and medullary brainstem structures. Using novel rotating frame adiabatic R₁ (i.e., measurements of longitudinal relaxation during adiabatic full passage pulses) and modified magnetization transfer (MT) MRI mapping, we sought to identify brainstem alterations in nine individuals with mild-moderate PD (off medication) and ten age-matched controls at 4 Tesla. We observed significant differences in MRI parameters within midbrain and medullary brainstem structures of PD patients as compared to controls that may be due to early stages of the disease.

Wu Li¹, Jiangtao Liu², Jie Tian¹, Yijun Liu³, and Kuncheng Li^2
1Institute of Automation, Chinese Academy of Sciences, Beijing, Beijing, China, ²Xuanwu Hospital, Capital Medical University,³McKnight Brain Institute, University of Florida

The neural basis of depression in Parkinson’s disease (PD) remains unclear. We aim to investigate diffusion changes in thalamus and subthalamus nucleus (STN) in PD patients with depression using DT-MRI. Voxel-based analysis was conducted in the regions of thalamus and STN among depressed PD (DPD) patients, non-depressed PD (NDPD) patients and healthy controls. Decreased fractional anisotropy was found in mediodorsal thalamus as well in the STN in DPD patients; while in NDPD patients, the decrease was found only in STN. Our results suggest the thalamic role and provide an explanation for the high percentage of depression in PD patients.