3T Magnetic Resonance Spectroscopy Research Articles

Investigating the brain's neurochemical profile at midlife in relation to dementia risk factors.

Changes in the brain's physiology in Alzheimer's disease are thought to occur early in the disease's trajectory. In this study our aim was to investigate the brain's neurochemical profile in a midlife cohort in relation to risk factors for future dementia using single voxel proton magnetic resonance spectroscopy. Participants in the multi-site PREVENT-Dementia study (age range 40-59 year old) underwent 3T magnetic resonance spectroscopy with the spectroscopy voxel placed in the posterior cingulate/precuneus region. Using LCModel, we quantified the absolute concentrations of myo-inositol, total N-acetylaspartate, total creatine, choline, glutathione and glutamate-glutamine for 406 participants (mean age 51.1; 65.3% female). Underlying partial volume effects were accounted for by applying a correction for the presence of cerebrospinal fluid in the magnetic resonance spectroscopy voxel. We investigated how metabolite concentrations related to apolipoprotein ɛ4 genotype, dementia family history, a risk score (Cardiovascular Risk Factors, Aging and Incidence of Dementia -CAIDE) for future dementia including non-modifiable and potentially-modifiable factors and dietary patterns (adherence to Mediterranean diet). Dementia family history was associated with decreased total N-acetylaspartate and no differences were found between apolipoprotein ɛ4 carriers and non-carriers. A higher Cardiovascular Risk Factors, Aging, and Incidence of Dementia score related to higher myo-inositol, choline, total creatine and glutamate-glutamine, an effect which was mainly driven by older age and a higher body mass index. Greater adherence to the Mediterranean diet was associated with lower choline, myo-inositol and total creatine; these effects did not survive correction for multiple comparisons. The observed associations suggest that at midlife the brain demonstrates subtle neurochemical changes in relation to both inherited and potentially modifiable risk factors for future dementia.

Fatty Acid Composition of Proximal Femur Bone Marrow Adipose Tissue in Subjects With Systemic Lupus Erythematous Using 3T Magnetic Resonance Spectroscopy.

Systemic lupus erythematosus (SLE) is a chronic, inflammatory disease with common musculoskeletal manifestations, notably reductions in bone quality. Bone marrow adipose tissue composition and quantity has been previously linked to bone quality and may play a role in SLE pathophysiology but has not been thoroughly studied. To use magnetic resonance spectroscopy (MRS) to investigate bone marrow adipose tissue quantity and composition in proximal femur subregions of untreated SLE patients compared to controls and treated patients. Prospective. A total of 64 female subjects: 28 SLE, 15 glucocorticoid (GC)-treated SLE and 21 matched controls. Stimulated echo acquisition mode (STEAM) sequence at 3 T. MRS was performed at multiple echo times in the femoral neck and trochanter regions and fatty acids (FA) composition was computed. Intergroup comparisons were carried out using ANOVA. A P value < 0.05 was considered statistically significant. SLE patients had significantly higher saturated FA compared to controls in both the femoral neck (+0.12) and trochanter (+0.11), significantly lower monounsaturated FA in the trochanter compared to controls (-0.05), and significantly lower polyunsaturated FA in the femoral neck compared to both controls (-0.07) and SLE patients on GC therapy (-0.05). SLE patients have altered proximal femur marrow fat metabolism, which may reflect a manifestation of, or play a role in, the altered inflammatory response of these patients. 2 TECHNICAL EFFICACY: Stage 2.

Regional specificity and clinical correlates of cortical GABA alterations in posttraumatic stress disorder.

Gamma-aminobutyric acid (GABA) metabolism is implicated in posttraumatic stress disorder (PTSD) and may be altered in prefrontal-limbic brain regions involved in arousal regulation. This study used proton magnetic resonance spectroscopy (MRS) to test the hypothesis that PTSD and trauma-exposed non-PTSD comparison (TENC) adults have significantly different GABA than healthy comparison (HC) subjects in two brain areas implicated in arousal (medial prefrontal cortex, insula) but not in a control brain area (posterior temporal cortex). We also examined whether GABA alterations correlated with hyperarousal and dissociation symptoms. One hundred and fourteen participants (39 PTSD, 34 TENC, 41 HC) underwent 3T MRS of the medial prefrontal, right insular, and right posterior temporal cortices, and the GABA plus macromolecule signal (GABA+) was normalized to creatine (Cr). The Clinician Administered PTSD Scale measured hyperarousal symptoms, including sleep disruption. The Dissociative Experiences Scale assessed dissociation symptoms. PTSD and TENC participants had significantly lower mPFC GABA+/Cr than HC participants, and this deficit was significantly correlated with greater dissociation. Compared with HC, PTSD patients but not TENC had significantly lower insula GABA+/Cr. Total hyperarousal symptoms and sleep disruption were not significantly associated with GABA+/Cr alterations in either region. Our findings point to lower GABA in cortical areas implicated in arousal regulation in PTSD and suggest that GABA alterations are associated with symptoms of trauma-related psychopathology but not always a biomarker of diagnosis. These findings also add to evidence that dissociation has distinct neural correlates within PTSD, including high excitability of medial prefrontal cortex.

Intermittent Theta-Burst Stimulation Transcranial Magnetic Stimulation Increases GABA in the Medial Prefrontal Cortex: A Preliminary Sham-Controlled Magnetic Resonance Spectroscopy Study in Acute Bipolar Depression.

Background: Magnetic resonance spectroscopy (MRS) has been used to identify gamma-aminobutyric acid (GABA) alterations in mood disorders, particularly in the medial prefrontal cortex (mPFC) where decreased concentrations have been associated with anhedonia. In major depressive disorder (MDD), prior work suggests that repetitive transcranial magnetic stimulation (rTMS) increases mPFC GABA concentrations proportional to antidepressant response. To our knowledge, this has not been examined in acute bipolar depression.Methods: As part of a multicentre 4-week randomized, double-blind, sham-controlled trial using intermittent theta-burst stimulation (iTBS) of the left dorsolateral prefrontal cortex (DLPFC) in individuals with acute bipolar depression, we quantified mPFC GABA and Glx (glutamate+glutamine) concentrations using a 3T MRS scan at baseline and after the intervention. Depressive symptoms were measured using the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating Scale-17 (HRDS-17), and anhedonia was measured using the Snaith-Hamilton Pleasure Scale (SHAPS).Results: The trial was terminated for futility and magnetic resonance spectroscopy data was acquired for 18 participants. At baseline, there were no associations between GABA or Glx concentrations and anhedonia, however GABA was negative correlated with depressive symptom severity on the HRDS-17. Compared to the sham-iTBS group, participants receiving active-iTBS had a significant increase in mPFC GABA concentrations. This was unrelated to antidepressant outcomes or improvements in anhedonia.Conclusion: Our data suggests that iTBS targeting the DLPFC is associated with physiological changes in the mPFC. In acute bipolar depression, our preliminary data suggests that mPFC GABA is dissociated from antidepressant iTBS treatment outcomes and anhedonia.

Role of Magnetic Resonance Spectroscopy in Evaluation of Cerebral Metabolic Status Before and After Carotid Endarterectomy/Thromboendarterectomy and Carotid Artery Stenting in Patients with Asymptomatic Critical Internal Carotid Artery Stenosis.

BackgroundThe relative efficacy of carotid endarterectomy (CEA)/thromboendarterectomy (TEA) and carotid artery stenting (CAS) already has been compared in randomized controlled trials and a meta-analysis, but only limited data exist describing the status of cerebral metabolism before and after these interventions.The aim of the present study was to compare metabolic changes before and after treatment of carotid stenosis and assess their potential clinical implications.Material/MethodsPatients with asymptomatic unilateral critical internal CAS were imaged with proton 3T magnetic resonance spectroscopy (H-MRS) because the technique is more sensitive than regular magnetic resonance imaging for detection of the early signs of ischemic events. Abnormal metabolite ratios detected with H-MRS may precede actual morphological changes associated with hypoperfusion as well as reperfusion changes. Ipsilateral and contralateral middle cerebral artery vascular territories were both evaluated before and after vascular intervention. H-MRS was performed within 24 h before and after surgery. Correlations in the metabolic data from H-MRS for N-acetylaspartic acid (NAA)+N-acetylaspartylglutamate, creatinine (Cr)+phosphocreatinine, and phosphocholine+glycerophosphocholine (Cho) were sought.ResultsH-MRS voxels from 11 subjects were analyzed. Values for dCho/CrI, dCho/CrC and Cho/Naal (P<0.001) were significantly higher ipsilaterally than contralaterally. Ratios for dNaa/ChoC and Cho/NaaC were significantly higher on the non-operated side (P<0.001).ConclusionsH-MRS may be helpful for assessment of patients with CAS, particularly because unlike other modalities, it reveals postoperative changes in metabolic brain status. Initial results indicate the important role of perioperative neuroprotective treatment.

Cognitive Performance and Neuro-Metabolites in HIV Using 3T Magnetic Resonance Spectroscopy: A Cross-Sectional Study from India.

Cognitive impairment in patients with human immunodeficiency virus (HIV) is associated with higher morbidity. The prevalence of the metabolite changes in the brain associated with cognitive impairment in anti-retroviral therapy naïve patients with HIV is unknown. To estimate the prevalence of the neurometabolites associated with cognitive impairment in antiretroviral therapy (ART) naïve patients with HIV. We conducted a cross-sectional study among ART naïve patients with HIV aged 18-50 years in a tertiary care center in India. Cognition was tested using the Post Graduate Institute battery of brain dysfunction across five domains; memory, attention-information processing, abstraction executive, complex perceptual, and simple motor skills. We assessed the total N-acetyl aspartyl (tNAA), creatine (tCr) and glutamate + glutamine (Glx) using 3T magnetic resonance spectroscopy. Cognitive impairment was defined as an impairment in ≥2 domains. Among 43 patients eligible for this study, the median age was 32 years (IQR 29, 40) and 30% were women. Median CD4 count and viral load were 317 cells/μL (IQR 157, 456) and 9.3 copies/ μL (IQR 1.4, 38), respectively. Impairment in at least one cognitive domain was present in 32 patients (74.4%). Impairment in simple motor skills and memory was present in 46.5% and 44% of patients, respectively. Cognitive impairment, defined by impairment in ≥2 domains, was found in 22 (51.2%) patients. There was a trend towards higher concentration of tNAA (7.3 vs. 7.0 mmol/kg), tGlx (9.1 vs. 8.2 mmol/kg), and tCr (5.5 vs. 5.2 mmol/kg) in the frontal lobe of patients with cognitive impairment vs. without cognitive impairment but it did not reach statistical significance (p>0.05 for all). There was no difference in the concentration of these metabolites in the two groups in the basal ganglia. There is a high prevalence of cognitive impairment in ART naïve patients with HIV. There is no difference in metabolites in patients with or without cognitive impairment. Further studies, with longitudinal follow-up are required to understand the underlying pathophysiological mechanisms.

Treatment response after 6 and 26 weeks is related to baseline glutamate and GABA levels in antipsychotic-naïve patients with psychosis.

Poor response to dopaminergic antipsychotics constitutes a major challenge in the treatment of psychotic disorders and markers for non-response during first-episode are warranted. Previous studies have found increased levels of glutamate and γ-aminobutyric acid (GABA) in non-responding first-episode patients compared to responders, but it is unknown if non-responders can be identified using reference levels from healthy controls (HCs). Thirty-nine antipsychotic-naïve patients with first-episode psychosis and 36 matched HCs underwent repeated assessments with the Positive and Negative Syndrome Scale and 3T magnetic resonance spectroscopy. Glutamate scaled to total creatine (/Cr) was measured in the anterior cingulate cortex (ACC) and left thalamus, and levels of GABA/Cr were measured in ACC. After 6 weeks, we re-examined 32 patients on aripiprazole monotherapy and 35 HCs, and after 26 weeks we re-examined 30 patients on naturalistic antipsychotic treatment and 32 HCs. The Andreasen criteria defined non-response. Before treatment, thalamic glutamate/Cr was higher in the whole group of patients but levels normalized after treatment. ACC levels of glutamate/Cr and GABA/Cr were lower at all assessments and unaffected by treatment. When compared with HCs, non-responders at week 6 (19 patients) and week 26 (16 patients) had higher baseline glutamate/Cr in the thalamus. Moreover, non-responders at 26 weeks had lower baseline GABA/Cr in ACC. Baseline levels in responders and HCs did not differ. Glutamatergic and GABAergic abnormalities in antipsychotic-naïve patients appear driven by non-responders to antipsychotic treatment. If replicated, normative reference levels for glutamate and GABA may aid estimation of clinical prognosis in first-episode psychosis patients.

Is glutamate associated with fear extinction and cognitive behavior therapy outcome in OCD? A pilot study.

Cognitive behavioral therapy (CBT) including exposure and response prevention is a well-established treatment for obsessive-compulsive disorder (OCD) and is based on the principles of fear extinction. Fear extinction is linked to structural and functional variability in the ventromedial prefrontal cortex (vmPFC) and has been consistently associated with glutamate neurotransmission. The relationship between vmPFC glutamate and fear extinction and its effects on CBT outcome have not yet been explored in adults with OCD. We assessed glutamate levels in the vmPFC using 3T magnetic resonance spectroscopy, and fear extinction (learning and recall) using skin conductance responses during a 2-day experimental paradigm in OCD patients (n = 17) and in healthy controls (HC; n = 13). Obsessive-compulsive patients (n = 12) then received manualized CBT. Glutamate in the vmPFC was negatively associated with fear extinction recall and positively associated with CBT outcome (with higher glutamate levels predicting a better outcome) in OCD patients. Glutamate levels in the vmPFC in OCD patients were not significantly different from those in HC, and were not associated with OCD severity. Our results suggest that glutamate in the vmPFC is associated with fear extinction recall and CBT outcome in adult OCD patients.

Neuro-Metabolite Changes in a Single Season of University Ice Hockey Using Magnetic Resonance Spectroscopy

Background: Previous research has shown evidence for transient neuronal loss after repetitive head impacts (RHI) as demonstrated by a decrease in N-acetylaspartate (NAA). However, few studies have investigated other neuro-metabolites that may be altered in the presence of RHI; furthermore, the relationship of neuro-metabolite changes to neurocognitive outcome and potential sex differences remain largely unknown.Objective: The aim of this study was to identify alterations in brain metabolites and their potential association with neurocognitive performance over time as well as to characterize sex-specific differences in response to RHI.Methods: 33 collegiate ice hockey players (17 males and 16 females) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation before and after the Canadian Interuniversity Sports (CIS) ice hockey season 2011–2012. The MRS voxel was placed in the corpus callosum. Pre- and postseason neurocognitive performances were assessed using the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). Absolute neuro-metabolite concentrations were then compared between pre- and postseason MRS were (level of statistical significance after correction for multiple comparisons: p < 0.007) and correlated to ImPACT scores for both sexes.Results: A significant decrease in NAA was observed from preseason to postseason (p = 0.001). Furthermore, a trend toward a decrease in total choline (Cho) was observed (p = 0.044). Although no overall effect was observed for glutamate (Glu) over the season, a difference was observed with females showing a decrease in Glu and males showing an increase in Glu, though this was not statistically significant (p = 0.039). In both males and females, a negative correlation was observed between changes in Glu and changes in verbal memory (p = 0.008).Conclusion: The results of this study demonstrate changes in absolute concentrations of neuro-metabolites following exposure to RHI. Results suggest that changes in Glu are correlated with changes in verbal memory. Future studies need to investigate further the association between brain metabolites and clinical outcome as well as sex-specific differences in the brain's response to RHI.

Neurocognitive Decline in People Living with HIV in India and Correlation with 3T Magnetic Resonance Spectroscopy

Background Neurocognitive decline in asymptomatic HIV patients and its correlation with metabolic changes in brain has not been studied in developing countries like India. In the present study we aim to examine the correlation between cognitive decline and changes in brain metabolites using MRS.Methods ART naïve HIV-positive patients, in the age group 2050 years attending ART center of the hospital from July to December 2016 were included in the study. All patients underwent evaluation using MRS of left frontal white matter (FWM) and left basal ganglia (BG). Levels of Nacetyl aspartate (tNAA), choline (tCho), creatine (tCr), lipids and macromolecules at 0.9ppm (Lip09+MM09) were measured. Cognition was tested using a battery validated for Indian population. Locally normalized zscores were used to calculate brain dysfunction score. Spearman correlation coefficient was used to assess the correlation between two continuous variables. There were 28 (29% female and 71% male) cases and 30 (37% female and 63% male) controls.ResultsThe mean age was comparable in the 2 groups (33 and 34 years). There was a significant difference (P < 0.05) in the concentration (mmol/kg) of tNAA (9.29 ± 311 vs. 7.45 ± 0.64), tCho (2.08 ± 0.70 vs. 1.74 ± 0.25), tCr (6.95 ± 2.56 vs. 5.43 ± 0.61), in the FWM and Lip09 + MM09 (5.87 ± 1.05 vs. 4.80 ± 0.35) in BG, with higher levels in controls. There was no significant correlation between CD4 count and metabolites or overall dysfunction score and metabolites except Cr in FWM with more dysfunction associated with lower concentration (see Table 1)Table 1:MR spectrum acquired from FWM of a patient.Graph 1:MR spectrum acquired from FWM of a patient.Conclusion The results show that HIV-associated changes are present in asymptomatic people which may be contributing to the early neurocognitive decline. Knowledge of metabolic changes within studied brain regions can help understand the pathology and design interventions to cater to this unmet need in people living with HIV.Disclosures All authors: No reported disclosures.

Altered Neurochemistry in Former Professional Soccer Players without a History of Concussion.

Soccer is played by more than 250 million people worldwide. Repeatedly heading the ball may place soccer players at high risk for repetitive subconcussive head impacts (RSHI). This study evaluates the long-term effects of RSHI on neurochemistry in athletes without a history of clinically diagnosed concussion, but with a high exposure to RSHI. Eleven former professional soccer players (mean age 52.0±6.8 years) and a comparison cohort of 14 age- and gender-matched, former non-contact sport athletes (mean age 46.9±7.9 years) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation. In the soccer players a significant increase was observed in both choline (Cho), a membrane marker, and myo-inositol (ml), a marker of glial activation, compared with control athletes. Additionally, ml and glutathione (GSH) were significantly correlated with lifetime estimate of RSHI within the soccer group. There was no significant difference in neurocognitive tests between groups. Results of this study suggest an association between RSHI in soccer players and MRS markers of neuroinflammation, suggesting that even subconcussive head impacts affect the neurochemistry of the brain and may precede neurocognitive changes. Future studies will need to determine the role of neuroinflammation in RSHI and the effect on neurocognitive function.

A longitudinal study of magnetic resonance spectroscopy Huntington's disease biomarkers.

Putaminal metabolites examined using cross-sectional magnetic resonance spectroscopy (MRS) can distinguish pre-manifest and early Huntington's Disease (HD) individuals from controls. An ideal biomarker, however, will demonstrate longitudinal change over short durations. The objective here was to evaluate longitudinal in vivo brain metabolite profiles in HD over 24 months. Eighty-four participants (30 controls, 25 pre-manifest HD, 29 early HD) recruited as part of TRACK-HD were imaged at baseline, 12 months, and 24 months using 3T MRS of left putamen. Automated putaminal volume measurement was performed simultaneously. To quantify partial volume effects, spectroscopy was performed in a second, white matter voxel adjacent to putamen in six subjects. Subjects underwent TRACK-HD motor assessment. Statistical analyses included linear regression and one-way analysis of variance (ANOVA). At all time-points N-acetyl aspartate and total N-acetyl aspartate (NAA), neuronal integrity markers, were lower in early HD than in controls. Total NAA was lower in pre-manifest HD than in controls, whereas the gliosis marker myo-inositol (MI) was robustly elevated in early HD. Metabolites were stable over 24 months with no longitudinal change. Total NAA was not markedly different in adjacent white matter than putamen, arguing against partial volume confounding effects in cross-sectional group differences. Total NAA correlations with disease burden score suggest that this metabolite may be useful in identifying neurochemical responses to therapeutic agents. We demonstrate almost consistent group differences in putaminal metabolites in HD-affected individuals compared with controls over 24 months. Future work establishing spectroscopy as an HD biomarker should include multi-site assessments in large, pathologically diverse cohorts.

Gender and age groups interactions in the quantification of bone marrow fat content in lumbar spine using 3T MR spectroscopy: A multivariate analysis of covariance (Mancova)

IntroductionThere is an age-related conversion of red to yellow bone marrow in the axial skeleton, with a gender-related difference less well established. Our purpose was to clarify the variability of bone marrow fat fraction (FF) in the lumbar spine due to the interaction of gender and age groups. Methods44 healthy volunteers (20 males, 30–65 years old and 24 females, 30–69 years old) underwent 3T magnetic resonance spectroscopy (MRS) and conventional MRI examination of the lumbar spine; single-voxel spectrum was acquired for each vertebral body (VB). After controlling body mass index (BMI), a two-way between-groups multivariate analysis of covariance (MANCOVA) assessed the gender and age group differences in FF quantification for each lumbar VB. ResultsThere was a significant interaction between gender and age group, p=.017, with a large effect size (partial η2=.330). However the interaction explained only 33% of the observed variance. Main effects were not statistically significant. BMI was non-significantly related to FF quantification. ConclusionsYoung males showed a high FF content, which declined in the 4th decade, then increased the next 3 decades to reach a FF content just below the initial FF means. Females’ FF were low in the 3rd decade, depicted an accelerated increase in the 4th decade, then a gradual increase the next 3 decades to reach a FF content similar to males’ values. Our findings suggest that quantification of bone marrow FF using MRS might be used as a surrogate biomarker of bone marrow activity in clinical settings.

Marrow adiposity recovery after early zoledronic acid treatment of glucocorticoid-induced bone loss in rabbits assessed by magnetic resonance spectroscopy

BackgroundAlthough there is an inverse relationship between bone mass and marrow adiposity, the reversal function of zoledronic acid (ZOL) on increased marrow fat has not been studied. The aim of our study is to use the 3T magnetic resonance spectroscopy (MRS) to characterize the dynamical change process of the marrow fat responding to early ZOL treatment in the rabbit model with glucocorticoid-induced bone loss. MethodsFifteen 20-week-old female New Zealand White rabbits were randomized to control group, methylprednisolone (MPS) group, and MPS+ZOL group equally. Bone mineral density (BMD) and marrow fat fraction (FF) at L3–L4 vertebrae and left proximal femur were measured by Dual-energy X-ray absorptiometry and MRS at week 0, 4, 8, and 12. The animals were euthanized at the end of our experiment and their left femurs were dissected out for the histopathological examination. ResultsThe MPS group demonstrated a remarkable increase in FF but a reduction in BMD compared with the controls at week 4 and 8, respectively (P<0.05 for all). Early treatment of ZOL can inhibit bone degeneration, although the bone mass would not recover to its original level. FF in MPS group exhibited a dramatic increase over time, with an increased FF variation (+31.6%, P=0.009) at week 4 from baseline and it was maintained until week 12 (+75.2%, P<0.001). In MPS+ZOL group, the FF returned to baseline value after the ZOL treatment. Comparing with the controls, larger marrow adipocyte density, the mean of the adipocyte diameter, and the percentage area of the adipocyte were observed in the MPS group (P<0.05 for all), whereas there were no significant differences in quantitative parameters of marrow adipocytes between the ZOL-treated group and the normal rabbits. ConclusionAn increase of the marrow adiposity is synchronized with the deterioration of the MPS-induced bone mass. A single dose of early ZOL can reverse the marrow adiposity to its original level completely.

Prostate cancer in magnetic resonance imaging: diagnostic utilities of spectroscopic sequences

The aim of our work is to determine the efficacy of a combined study 3 Tesla Magnetic Resonance Imaging (3T MRI), with phased-array coil, for the detection of prostate cancer using magnetic resonance spectroscopy (MRS) and diffusion-weighted images (DWI) in identifying doubt nodules. In this study, we prospectively studied 46 patients who consecutively underwent digital-rectal exploration for high doses of prostate specific antigen (PSA), as well as a MRI examination and a subsequent rectal biopsy. The study of magnetic resonance imaging was performed with a Philips Achieva 3T scanner and phased-array coil. The images were obtained with turbo spin-echo sequences T2-weighted images, T1-weighted before and after the administration of contrast medium, DWI sequences and 3D spectroscopic sequences. The ultrasound-guided prostate biopsy was performed approximately 15 days after the MRI. The data obtained from MR images and spectroscopy were correlated with histological data. MRI revealed sensitivity and specificity of 88% and 61% respectively and positive predictive value (PPV) of 73%, negative predicted value (NPV) of 81% and accuracy of 76%. In identifying the location of prostate cancer, the sensitivity of 3T MRS was 92%, with a specificity of 89%, PPV of 87%, NPV of 88% and accuracy of 87%; DWI showed a sensitivity of 88%, specificity of 61%, PPV of 73%, NPV of 81% and accuracy of 76%. The 3T MR study with phased-array coil and the use of DWI and spectroscopic sequences, in addition to T2-weighted sequences, revealed to be accurate in the diagnosis of prostate cancer and in the identification of nodules to be biopsied. It may be indicated as a resolute way before biopsy in patients with elevated PSA value and can be proposed in the staging and follow-up.

MR proton spectroscopy for myocardial lipid deposition quantification: A quantitative comparison between 1.5T and 3T

To evaluate 3T magnetic resonance spectroscopy (MRS)-derived myocardial fat-signal fractions in comparison with those from 1.5T MRS. We conducted phantom, ex vivo and in vivo myocardial specimen evaluations at both 1.5T and 3T using (1)H-MRS. A phantom with nine fat-water emulsions was constructed to assess the accuracy of the spectroscopy measurements. Ex vivo spectroscopy data were acquired in 70 segments from 21 autopsy heart slices. In vivo spectroscopy data were acquired in the interventricular septum from 22 human volunteers. Phantom experiments demonstrated that 1.5T and 3T measurements were highly correlated with the reference values (r = 0.78, P < 0.05). The ex vivo and in vivo experiments demonstrated an increase in signal-to-noise ratio (SNR) of 45 ± 73% and 76 ± 72% at 3T compared to 1.5T (P < 0.05). The mean fat-signal fraction was similar at 3T and 1.5T (1.11 ± 1.18 vs. 1.00 ± 1.09, respectively, P = NS) in ex vivo studies but were significantly different in the in vivo studies (2.47 ± 1.46 vs. 1.56 ± 1.34, P < 0.05). The fat-signal fractions from 3T and 1.5T correlated fairly well in all experiments. 3T MRS has significantly greater SNR and could potentially be more accurate as compared to 1.5T for quantification of myocardial fat fraction in in vivo studies.

IC‐P‐067: 3T magnetic resonance spectroscopy of the posterior cingulate following rivastigmine treatment in Alzheimer's disease

IC‐P‐067: 3T magnetic resonance spectroscopy of the posterior cingulate following rivastigmine treatment in Alzheimer's disease

P1‐166: 3T magnetic resonance spectroscopy of the posterior cingulate following rivastigmine treatment in Alzheimer's disease

P1‐166: 3T magnetic resonance spectroscopy of the posterior cingulate following rivastigmine treatment in Alzheimer's disease

Polyphenon E, a Green Tea Extract, Increases Brain NAA Levels in MS: A Pilot Six Month Open Label Study (P03.050)

Objective: Assess the safety of Polyphenon E in subjects with multiple sclerosis (MS) and determine whether Polyphenon E would be futile as a neuroprotective agent. Background Polyphenon E (Mitsui Norin; Shizuoka, Japan) is an extract from the leaves of green tea. Its main active component is epigallocatechin gallate (EGCG), an antioxidant that accumulates within the mitochondria of neurons and increases their resistance to apoptosis under conditions of oxidative stress. Mitochondrial dysfunction leads to axonal injury in mice with experimental autoimmune encephalomyelitis (EAE). EGCG effectively treats EAE in female SJL/J mice. Design/Methods: Ten subjects with relapsing remitting or secondary progressive MS were recruited for this open-label, six-month pilot study of 400 mg of Polyphenon E twice daily. Adverse events (AE) were assessed monthly. N-acetyl aspartate (NAA) levels were measured using 3T magnetic resonance spectroscopy and differences were assessed between baseline and six-months. Plasma levels of epigallocatechin gallate (EGCG) were measured at one month, 3 and 8 hours after the morning dose. Results: No serious AE occurred. All subjects completed the study assessments. One discontinued therapy after mild elevation of liver enzymes. Treatment with EGCG resulted in an increase of 13% [95%,CI(1%-23%) p Conclusions: There were no safety concerns for treating MS patients with Polyphenon E. Our futility endpoint was rejected, as NAA levels increased. This and the correlated changes in NAA and EGCG levels support a potential neuroprotective effect that should be investigated in a larger randomized, placebo-controlled trial measuring NAA levels over a longer follow-up. Supported by: NCCAM K23AT004433; LSUHSC-New Orleans CTRC. Disclosure: Dr. Ramos has nothing to disclose. Dr. Garrison has nothing to disclose. Dr. Koop has nothing to disclose. Dr. Rooney has nothing to disclose. Dr. Bourdette has received personal compensation for activities with Biogen Idec, Serono, and Teva Neurosciences as a speaker. Dr. Lovera has received personal compensation for activities with EMD Serono, Teva Neuroscience, and Biogen Idec as a consultant.

Strengths and Weaknesses of 1.5T and 3T MRS Data in Brain Glioma Classification

Although magnetic resonance spectroscopy (MRS) methods of 1.5Tesla (T) and 3T have been widely applied during the last decade for noninvasive diagnostic purposes, only a few studies have been reported on the value of the information extracted in brain cancer discrimination. The purpose of this study is threefold. First, to show that the diagnostic value of the information extracted from two different MRS scanners of 1.5T and 3T is significantly influenced in terms of brain gliomas discrimination. Second, to statistically evaluate the discriminative potential of publicly known metabolic ratio markers, obtained from these two types of scanners in classifying low-, intermediate-, and high-grade gliomas. Finally, to examine the diagnostic value of new metabolic ratios in the discrimination of complex glioma cases where the diagnosis is both challenging and critical. Our analysis has shown that although the information extracted from 3T MRS scanner is expected to provide better brain gliomas discrimination; some factors like the features selected, the pulse-sequence parameters, and the spectroscopic data acquisition methods can influence the discrimination efficiency. Finally, it is shown that apart from the bibliographical known, new metabolic ratio features such as N-acetyl aspartate/ S, Choline/ S, Creatine/ S , and myo-Inositol/ S play significant role in gliomas grade discrimination.