Uzay Emrah Emir¹, Susan Rolandelli¹, Paul Joseph Tuite¹, and Gulin Oz^1
1University of Minnesota, Minneapolis, MN, United States

Measuring neurochemical alterations in affected mid-brain structures substantia nigra (SN) and putamen in Parkinson's disease (PD) by ¹H MRS has been challenging. Because recent pathological findings indicated earlier involvement of more caudal brainstem regions in PD before the nigrostriatal system, we measured neurochemical profiles of the pons, as well as the SN and putamen, in early-moderate PD by 7T ¹H MRS. GABA concentration was higher in the pons (p<0.001) and putamen (p = 0.06) in PD patients (N=11) compared to age-matched healthy controls (N=8). Further research will help determine how these changes relate to disease pathogenesis and pathophysiology.

Monika Dezortova¹, Vit Herynek¹, Martin Krssak², Claudia Kronnerwetter³, and Milan Hajek^1
1MR-Unit, Dept Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, ²Center for Medical Physics and Biomedical Engineering & MR Centre of Excellence, Medical University of Vienna, Vienna, Austria, ³Dept Radiology & MR Centre of Excellence, Medical University of Vienna, Vienna, Austria

Panthotenate-kinase associated neurodegeneration is characterized by iron accumulation in the basal ganglia. Iron deposits were studied using T2 MR relaxometry at 1.5T, 3T and 7T in three patients and five controls. T2 values of patients decreased significantly in the globus pallidus, increased in the putamen and nucleus caudate, and did not differ in the thalamus and white matter; the iron concentrations in the globus pallidus calculated for B₀=1.5T were approximately twice as high as in controls. Measurements at different magnetic fields suggest different ferritin loads in the basal ganglia in patients. However, the presence of other metalloproteins cannot be excluded.

Andreas Schäfer¹, Derek V Ott², Almut Focke², Johannes Schwarz², David Weise², Robert Turner¹, and Sonja A Kotz^1
1Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ²University Hospital, Leipzig, Germany

Pathological studies have shown that the iron content in the Substantia Nigra is increased in Parkinson patients. It has been shown that susceptibility mapping may indicate a higher iron concentration of the SN in vivo in clinically diagnosed but not medicated PD patients compared to young healthy volunteers. Here we present results of a continuing study by calculating the susceptibility of the SN of an age-matched control group, and also comparing the susceptibility values of the patients after one year of diagnosis and treatment.

Michael Zeineh¹, Hagen Kitzler², Scott Atlas¹, Hannes Vogel³, and Brian Rutt^1
1Radiology, Stanford University, Stanford, CA, United States, ²Neuroradiology, 2Department of Neuroradiology, Technische Universitaet Dresden, Germany, ³Pathology, Stanford University, Stanford, CA, United States

Iron-containing beta-amyloid plaques may play a key role in the development of Alzheimer’s disease (AD). To attempt to visualize the iron component of plaques, we performed high-resolution GRE imaging at 7.0T of AD specimens, and derived susceptibility maps from the phase images. Bright foci on the susceptibility maps corresponded closely with dark foci on the GRE images, suggesting plaques demonstrated positive magnetic susceptibility, possibly due to microscopic iron.

Jullie W Pan¹, Dennis D Spencer¹, R. Bradley Duckrow², Nikolai Avdievich¹, and Hoby P Hetherington^1
1Neurosurgery, Yale University School of Medicine, New Haven, CT, United States, ²Neurology, Yale University School of Medicine, New Haven, CT, United States

The presence of unilateral hippocampal atrophy in the evaluation of medial temporal lobe epilepsy (MTLE) is often a defining factor that if concordant with the EEG and PET and not contraindicated from neuropsychological data, will typically result in candidacy for surgical resection. However, it is possible to have hippocampal atrophy (HA) without intractable seizures particularly in familial MTLE. We used ultra-high field MR spectroscopic imaging at 7T to assess MTLE with patients who are all HA positive. We studied n=12 patients who were medically intractable and n=2 patients who were very well controlled (seizure free for >2years on medication).

Anouk Marsman¹, Dennis Klomp², Jannie Wijnen², Martijn Van den Heuvel¹, Vincent Boer², Peter Luijten², and Hilleke Hulshoff Pol^1
1Psychiatry, University Medical Center Utrecht, Utrecht, Netherlands, ²Radiology, University Medical Center Utrecht, Utrecht, Netherlands

Glutamate is the major excitatory neurotransmitter in the central nervous system and is involved in functions that alter with age. Using 1H-MRS (STEAM) at 7 Tesla, glutamate was measured in the medial frontal cortex of young adults, in which a decrease in glutamate concentration with increasing age was found. The decrease in glutamate concentration is in line with the gray matter thinning in medial frontal cortex in young adulthood. However, the change in glutamate is larger than the gray matter change, therefore we postulate that the observed effect is due to physiological changes rather than anatomical changes.

Lazar Fleysher¹, Niels Oesingmann², Ryan Brown¹, Hina Jaggi¹, Graham Wiggins¹, Daniel Sodickson¹, and Matilde Inglese^1,3
1Radiology, NYU School of Medicine, New York, New York, United States, ²Siemens Medical Solutions USA, Malvern, PA, United States, ³Neurology, NYU School of Medicine, New York, New York

Many morphologic MRI-based studies reported age-associated volume loss of the cerebral gray and white matters in normal aging. In this work, we report age-related changes in the tissue sodium concentration (TSC) in the healthy human brain. We find that TSC increases in gray and white matter with age consistent with cellular loss or shrinkage. The measured rate of fractional intracellular sodium volume fraction (ISVF) loss is found to be significantly different from the rate of fractional tissue volume loss for both GM and WM measured by morphologic MRI. This difference can be explained by the micro-structural changes in GM and WM associated with normal aging.

Michael Kwan-Yoe Liem¹, Saskia A.J. Lesnik Oberstein², Maarten J. Versluis¹, Joost Haan³, Andrew G Webb¹, Michel D Ferrari³, Mark A van Buchem¹, and Jeroen van der Grond^1
1Radiology, Leiden University Medical Center, Leiden, Netherlands, ²Clinical Genetics, Leiden University Medical Center, Leiden, Netherlands, ³Neurology, Leiden University Medical Center, Leiden, Netherlands

In this study we quantified diffuse iron deposition in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), using phase and magnitude imaging on 7 Tesla MRI. Twenty-five CADASIL patients and 15 healthy controls were examined using high resolution T2* imaging on 7 Tesla MRI. Increased phase shift and reduced signal intensity were found in the putamen and caudate nucleus of CADASIL patients which is likely caused by increased diffuse iron accumulation. In the cortex and white matter no signs of increased iron accumulation were found.