SPM Analysis Research Articles

An investigation of near-infrared photoluminescence from AP-MOVPE grown InSb/GaSb quantum dot structures

Abstract In this work, the near-infrared photoluminescence (PL) of InSb/GaSb QD structures grown on GaSb substrate (2° off (100)) using atmospheric pressure Metalorganic Vapor Phase Epitaxy is investigated. The structures are analyzed before capping and after capping using scanning probe microscopy and high resolution transmission electron microscopy (HRTEM), respectively. At 10 K, with an excitation power of 2 mW, a PL peak at ∼ 732 meV is observed. Upon an increase in laser power to 120 mW, a blue shift of ∼ 8 meV is noticed. This emission typically persists up to 60–70 K, after which it becomes weak. An SPM analysis of the size distribution of uncapped dots reveals a mono-modal distribution with an average density of ∼ 5×10 10 cm −2 . However, a HRTEM investigation of the capped dots reveals the formation of an InGaSb quantum well-like structure, ∼ 10 nm thick, which gives rise to the PL signal mentioned above.

Cerebral blood perfusion changes in amputees with myoelectric hands after rehabilitation: a SPECT computer-aided analysis.

BackgroundRehabilitation, which is essential for amputees with myoelectric hands, can improve the quality of daily life by remodeling the neuron network. In our study, we aim to develop a cerebral blood perfusion (CBF) single-photon emission computed tomography computer-aided (SPECT-CA) detection scheme to automatically locate the brain’s activated regions after rehabilitation.ResultsFive participants without forearms (three male, two female, mean age 51 ± 12.89 years, two missing the right side, and three missing the left side) were included in our study. In the clinical assessment, all of the participants received higher scores after training. The results of the SPM analysis indicated that CBF in the precentral gyrus, postcentral gyrus, frontal lobe, temporal lobe and cerebellum was significantly different among the five participants (P < 0.05). Moreover, SPECT-CA showed that the activated brain areas mainly included the precentral gyrus, postcentral gyrus, cerebellum and extensive cerebral cortex.ConclusionOur study demonstrated that the CBF SPECT-CA method can detect the brain blood perfusion changes induced by rehabilitation with high sensitivity and accuracy. This method has great potential for locating the remodeled neuron regions of amputees with myoelectric hands after rehabilitation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12868-016-0294-3) contains supplementary material, which is available to authorized users.

Brain Network Underlying the Improvement of Social Functioning in Schizophrenic Patients After One-year Treatment with Social Skills Training.

To assess changes in social and neuro-cognition and regional cerebral blood flow (rCBF) in schizophrenic patients with psychotic syndrome treated with Social Skill Training (SST). 17 patients underwent two high resolution rCBF SPECT at rest before and after a one-year treatment with SST. Patients were assessed using a neuropsychological evaluation (W.A.I.S.-R, T.M.T, Verbal Fluency, W.C.S.T.). SPM8 was used to investigate rCBF changes from the pre- to the post-SST condition and the relationship between rCBF and clinical scores used as covariates of interest. All patients presented with an improvement in social perception, ability to deal with abstract social conventions, rules and judgments about people (Comprehension and Picture Completion sub-tests) and some neuro-cognitive functions sustaining the process of socially relevant information. The main effect of SST was to produce rCBF increases in precuneus, PCC, superior parietal lobules, PMC, pre-SMA, precentral gyrus, dmPFC, dlPFC, vmPFC, OFC (p<0.0001 uncorrected). The SPM analysis showed that Comprehension was supported by PMC, dmPFC, OFC and vmPFC, while the Picture Completion was supported by PMC and dmPFC (p&lt;0.0001). SST in schizophrenic patients improves resting neural activity in cortical areas of the amigdala-based and non-amygdala networks of social brain, including dmPFC and vmPFC, and dlPFC, which are known to be part of default mode and task-positive networks and to be implicated in schizophrenia.

Effects of Manganese Exposure on Olfactory Functions in Teenagers: A Pilot Study.

Long-term exposure to environmental manganese (Mn) affects not only attention and neuromotor functions but also olfactory functions of a pre-adolescent local population who have spent their whole life span in contaminated areas. In order to investigate the effect of such exposure at the level of the central nervous system we set up a pilot fMRI experiment pointing at differences of brain activities between a non-exposed population (nine subjects) and an exposed one (three subjects). We also measured the volume of the olfactory bulb as well as the identification of standard olfactory stimuli. Our results suggest that young subjects exposed to Mn exhibit a reduction of BOLD signal, subjective odor sensitivity and olfactory bulb volume. Moreover a region of interest SPM analysis showed a specifically reduced response of the limbic system in relation to Mn exposure, suggesting an alteration of the brain network dealing with emotional responses.

Brief mindfulness training alters causal brain connections in mTBI

Traumatic brain injury (TBI) is a significant cause of disability in the United States and the mild TBI (mTBI) is the most prevalent. Previous research indicates the positive effect of mindfulness training on symptoms of chronic mTBI such as cognitive functioning and emotion [1]. However it remains unclear which brain regions play a crucial role in mTBI recovery and the causal relationship among these regions. Here we apply a dynamic causal modeling (DCM) in resting state fMRI [2] to demonstrate the causal relationships among the core regions involved in mTBI. Fourteen veteran students with mTBI were recruited through campus advertisements. We used 2 weeks of integrative body-mind training as mindfulness intervention, previously reported in our series of randomized studies [3,4]. All data were collected using a 3-Telsa Siemens Skyra scanner. Functional data were processed using the Data Processing Assistant for Resting-State fMRI, which is based on SPM and Resting-State fMRI Data Analysis Toolkit. Based on literature, we specified four regions of interest within default mode network (DMN) - medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and bilateral inferior parietal lobule (Left IPL and Right IPL), same regions and coordinates as in previous sDCM studies [2,5]. Based on SPM12, we estimated and specified the DCM for each subject and later compared the differences of effective connectivity before and after mindfulness. Our results suggest the different causal relationships following mindfulness training. Specifically, after training there was a significant decrease in the strength of excitatory input from mPFC to PCC, and a significant increase in the strength of inhibitory input from mPFC to LIPL (all p<0.05).

Mapping the smoking addiction using dynamic causal modelling at rest

Tobacco use is the leading preventable cause of death. Previous research show that brain areas including medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC) and others involved in smoking addiction [1]. However it remains unclear which brain regions play a crucial role in smoking addiction and the relationship among these regions. Since functional connectivity does not support inferences about causal brain connections, the changes in information flow in these distributed systems involved in smoking remain largely unknown. Here we apply a dynamic causal modeling (DCM) in resting state fMRI [2] to demonstrate the causal relationships among the core regions in smoking addiction. Healthy college students were recruited through campus advertisements. Among those who responded, there were 14 cigarette smokers and 14 nonsmokers. All data were collected using a 3-Telsa Siemens Skyra scanner. Functional data were processed using the Data Processing Assistant for Resting-State fMRI, which is based on SPM (www.fil.ion.ucl.ac.uk/spm) and Resting-State fMRI Data Analysis Toolkit. Based on literature, we specified four regions of interest (ROIs) within the default mode network (DMN), which are medial prefrontal cortex (mPFC), posterior cingulate cortex (PCC), and bilateral inferior parietal lobule ( Left IPL and Right IPL), same regions and coordinates as in previous studies that use sDCM analysis for resting state [2,3]. Based on SPM12, we estimated and specified the DCM for each subject and later compared the differences of effective connectivity between two groups by using two-sample test. Our results suggest the different causal relationships between nonsmokers and smokers. Specifically, there was a lower strength of excitatory input from PCC to mPFC for smokers than nonsmokers and a lower strength of excitatory input from RIPL to mPFC for smokers than nonsmokers (all p<0.05).

Cerebral Blood Flow Improvement after Indirect Revascularization for Pediatric Moyamoya Disease: A Statistical Analysis of Arterial Spin-Labeling MRI.

The severity of Moyamoya disease is generally scaled with conventional angiography and nuclear medicine. Arterial spin-labeling MR imaging is now acknowledged for the noninvasive quantification of cerebral blood flow. This study aimed to analyze CBF modifications with statistical parametric mapping of arterial spin-labeling MR imaging in children undergoing an operation for Moyamoya disease. We included 15 children treated by indirect cerebral revascularization with multiple burr-holes between 2011 and 2013. Arterial spin-labeling MR imaging and T1 sequences were then analyzed under SPM8, according to the general linear model, before and after the operation (3 and 12 months). Voxel-based analysis was performed at the group level, comparing all diseased hemispheres with all normal hemispheres and, at the individual level, comparing each patient with a control group. Group analysis showed statistically significant preoperative hypoperfusion in the MCA territory in the Moyamoya hemispheres and a significant increase of cerebral perfusion in the same territory after revascularization (P < .05 family-wise error-corrected). Before the operation, individual analysis showed significant hypoperfusion for each patient co-localized with the angiographic defect on DSA. All except 1 patient had improvement of CBF after revascularization, correlated with their clinical status. SPM analysis of arterial spin-labeling MR imaging offers a noninvasive evaluation of preoperative cerebral hemodynamic impairment and an objective assessment of postoperative improvement in children with Moyamoya disease.

Complementarity of visual and voxel-based FDG-PET analysis to detect MCI-like hypometabolic pattern in elderly patients with hypertension and isolated memory complaints.

18F-FDG PET can be used to aid in the diagnosis of Alzheimer's disease (AD) and clarify the diagnosis and prognosis of patients with mild cognitive impairment (MCI). To compare the results of a quantitative analysis of FDG-PET brain images to a standard visual analysis (SVA) with regards to the detection of MCI-like hypometabolic pattern in elderly patients with hypertension and subjective, isolated memory complaints. FDG-PET brain was performed in 71 patients (mean age, 76.4 ± 5.1 years; women, 53.5%). Images were analyzed for the presence of an MCI-like hypometabolic pattern using an SVA by 2 physicians and a voxel-based statistical procedure (statistical parametric mapping [SPM]) that compared each patient's images to normal reference samples from 19 elderly individuals obtained using the same PET camera. The reliability of these analyses was evaluated according to neuropsychological assessment results, including the Grober & Buschke Free and Cued Selective Reminding Test, and a combined analysis by a neuropsychologist. An MCI-like hypometabolic pattern was documented in 5 patients (7%) by SVA and 7 patients (10%) by SPM analysis; however, only 2 of these patients were selected by both methods. The group characteristics of the 7 patients identified by the quantitative method were consistent with the MCI pattern, which included a higher rate of abnormal GB-FCSRT in Free Recall (57% vs. 9%, p < 0.05) or in Total Recall (29% vs. 8%, p < 0.05) when compared with other patients. In contrast, the group identified by SVA did not exhibit these characteristics. A combined visual and quantitative analysis improves the diagnostic accuracy to detect an MCI-like hypometabolic pattern in elderly patients with hypertension and subjective, isolated memory complaints.

Lower limb landing biomechanics in subjects with chronic ankle instability.

The literature on lower limb kinematic deviations in subjects with chronic ankle instability (CAI) during landing tasks is limited and not consistent. Several studies only report joint angles at defined events rather than considering the whole kinematic curve, which might obscure possibly relevant information. Therefore, the main goal of this study was to evaluate landing kinematics of the lower limb in subjects with CAI using curve analysis. Lower limb kinematics of 56 subjects (28 subjects with self-reported CAI and 28 matched healthy controls) were measured during a barefoot forward and side jump protocol. Kinematic data were collected in a laboratory setting using an eight-camera optoelectronic system. Ground reaction forces were registered by means of a force plate built into the landing zone. After completion of each task, difficulty level and subjective stability at the ankle joint were documented using a visual analog scale. To compare between groups, statistical parametric mapping was used to assess group differences between mean joint angles over the entire impact phase. SPM analysis of kinematic curves of the hip, knee, and ankle showed no significant differences between the subjects with CAI and the control group independent of jump direction. Subjects with CAI did report higher feelings of instability for both landing tasks and a higher difficulty level for the forward jump. Our results showed no altered lower limb kinematics in subjects with CAI compared to a healthy control group during a forward and side jump landing task. Therefore, these results question the hypothesis of kinematic deviations as part of an underlying mechanism of CAI.

18F-FDG PET imaging for characteristics of cerebral glucose metabolism in patients with progressive supranuclear palsy

Objective To validate the reproducibility of abnormal cerebral glucose metabolic characteristics in patients with progressive supranuclear palsy (PSP) from different regions using 18F-FDG PET imaging. Methods Ten patients with PSP and 10 age-matched healthy controls from Shanghai Huashan Hospital (H1), as well as 13 patients with PSP and 13 age-matched healthy controls from Beijing Union Hospital (H2) were recruited to perform resting-state brain 18F-FDG PET imaging. The cerebral metabolic characteristics of patients were investigated using SPM with two-sample t test. Results The features of cerebral glucose metabolism by SPM analysis in PSP patients from H1 were demonstrated as decreased metabolism in midbrain, and bilaterally decreased metabolism in thalamus, caudate, medial prefrontal cortex and ventrolateral prefrontal cortex(t:5.26-11.00, all P<0.001). Meanwhile, the similar hypometabolism in addition to that in the angular gyrus was found in patients with PSP from H2 (t: 4.55-5.56, all P<0.001). Conclusion Decreased metabolism exsists in the midbrain, thalamus, caudate, medial prefrontal cortex and ventrolateral prefrontal cortex of patients with PSP from different regions, which provide reliable evidence for the multi-center study about differential diagnosis of PSP based on 18F-FDG PET imaging. Key words: Supranuclear palsy, progressive; Deoxyglucose; Metabolism; Tomography, emission-computed

Standardizing Metadata in Brain Imaging

Standardizing Metadata in Brain Imaging

FDG μPET Fails to Detect a Disease-Specific Phenotype in Rats Transgenic for Huntington's Disease – A 15 Months Follow-up Study

FDG-PET detects hypometabolism in premanifest and symptomatic Huntington's disease (HD). A cross-sectional study suggested that whole-brain FDG-PET is capable to detect a phenotype in transgenic (tg) HD rats. Recently, a longitudinal follow-up study showed no FDG-PET changes in tgHD rats. Both studies applied small sample sizes and analysis was limited to whole-brain or striatum. We therefore performed a follow-up study in a larger cohort of tgHD and wild-type (wt) rats encompassing several pre-defined regions of interest (ROIs) and hypothesis free voxel-by-voxel SPM analysis to clarify whether FDG-PET can detect a phenotype in tgHD rats and to determine onset …and effect sizes of changes over time. N = 19 tgHD- and n = 20 wt-rats, mixed gender, were included. Repeated small animal FDG-μPET and MRI were performed at 5,10,15, and 20 months of age. ROIs encompassing entire brain, cortex, striatum, thalamus, subventricular-zone, and cerebellum were placed manually on the MRI and transferred to the co-registered μPET. Mean and maximal FDG-PET activities within ROIs were calculated and normalized to cerebellar FDG uptake. Activity and spatially normalized FDG-μPET were compared between groups on a hypothesis-free voxel-by-voxel basis using SPM. FDG uptake showed changes over time in both tgHD- and wt-rats, however, there was no consistent difference between tgHD- and wt-rats in both the manual ROI and SPM analysis. In this transgenic rat model of HD FDG-μPET imaging does not detect significant alterations at the ages investigated. Further investigations are warranted employing other age groups and alternative imaging biomarkers for neuronal degeneration, respectively.

Processing Sentences with Literal versus Figurative Use of Verbs: An ERP Study with Children with Language Impairments, Nonverbal Impairments, and Typical Development.

Forty native Italian children (age 6–15) performed a sentence plausibility judgment task. ERP recordings were available for 12 children with specific language impairment (SLI), 11 children with nonverbal learning disabilities (NVLD), and 13 control children. Participants listened to verb-object combinations and judged them as acceptable or unacceptable. Stimuli belonged to four conditions, where concreteness and congruency were manipulated. All groups made more errors responding to abstract and to congruent sentences. Moreover, SLI participants performed worse than NVLD participants with abstract sentences. ERPs were analyzed in the time window 300–500 ms. SLI children show atypical, reversed effects of concreteness and congruence as compared to control and NVLD children, respectively. The results suggest that linguistic impairments disrupt abstract language processing more than visual-motor impairments. Moreover, ROI and SPM analyses of ERPs point to a predominant involvement of the left rather than the right hemisphere in the comprehension of figurative expressions.

Improved dopamine transporter binding activity after bone marrow mesenchymal stem cell transplantation in a rat model of Parkinson's disease: small animal positron emission tomography study with F-18 FP-CIT.

We evaluated the effects of bone marrow-derived mesenchymal stem cells (BMSCs) in a model of Parkinson's disease (PD) using serial F-18 fluoropropylcarbomethoxyiodophenylnortropane (FP-CIT) PET. Hemiparkinsonian rats were treated with intravenously injected BMSCs, and animals without stem cell therapy were used as the controls. Serial FP-CIT PET was performed after therapy. The ratio of FP-CIT uptake in the lesion side to uptake in the normal side was measured. The changes in FP-CIT uptake were also analyzed using SPM. Behavioural and histological changes were observed using the rotational test and tyrosine hydroxylase (TH)-reactive cells. FP-CIT uptake ratio was significantly different in the BMSCs treated group (n = 28) at each time point. In contrast, there was no difference in the ratio in control rats (n = 25) at any time point. SPM analysis also revealed that dopamine transporter binding activity was enhanced in the right basal ganglia area in only the BMSC therapy group. In addition, rats that received BMSC therapy also exhibited significantly improved rotational behaviour and preservation of TH-positive neurons compared to controls. The therapeutic effect of intravenously injected BMSCs in a rat model of PD was confirmed by dopamine transporter PET imaging, rotational functional studies, and histopathological evaluation. • Mesenchymal stem cells were intravenously injected to treat the PD rats • Dopamine transporter binding activity was improved after stem cell therapy • Stem cell therapy induced functional recovery and preservation of dopaminergic neurons • The effect of stem cells was confirmed by FP-CIT PET.

Physical property changes of sandstones in Korea derived from the supercritical CO2-sandstone‒groundwater geochemical reaction under CO2 sequestration condition

Laboratory experiments and calculation of the dissolution constant were performed to investigate the physical property changes of sandstones in Korea resulting from the geochemical reaction of CO2 under sequestration conditions. To simulate the sub-surface storage condition (100 bar and 50 °C), the high pressurized stainless cell and chamber were used and the supercritical CO2 fluid was injected into the cell (or the chamber) by the syringe pump and the pressure regulator. Sandstone slabs and cores were used for the experiments of the supercritical CO2-sandstone‒groundwater reaction. Results of SEM/EDS and SPM analyses showed that the surface roughness of the slab increased and the precipitation of calcite, halite, and Ca-rich silicate minerals on the sandstone slab occurred during 60 days reaction, suggesting the geochemical weathering process, as a result of CO2 injection, directly leads to property changes of sandstones in a short time. The average porosity of sandstone cores as increased 8.8% with the corresponding decreases in the dry density, P and S wave velocity, dynamic Young’s modulus, and the uniaxial compression strength, indicating that the trend of property changes for the sandstone was well fitted to the first-order reaction curve. The average first-order dissolution constant (K 1) of sandstones, calculated by using the loss of sandstone mass during the reaction time was 0.0000846 day−1. The K 1 values will be useful for estimating the dissolution process of sandstones originated from the supercritical CO2-sandstone‒groundwater reaction while the CO2 was injected into the sub-surface.

Glucose Metabolism in the Primary Auditory Cortex of Postlingually Deaf Patients: An FDG-PET Study

Background/Purpose: Previous FDG-PET studies have indicated neuroplasticity in the adult auditory cortex in cases of postlingual deafness. In the mature brain, auditory deprivation decreased neuronal activity in primary auditory and auditory-related cortices. In order to reevaluate these issues, we used statistical analytic software, namely a three-dimensional stereotaxic region of interest template (3DSRT), in addition to statistical parametric mapping (SPM; Institute of Neurology, University College of London, UK). MaterialsandMethods:¹⁸F-FDG brain PET scans were performed on 7 postlingually deaf patients and 10 healthy volunteers. Significant increases and decreases of regional cerebral glucose metabolism in the patient group were estimated by comparing their PET images with those of healthy volunteers using SPM analysis and 3DSRT. Results: SPM revealed that the glucose metabolism of the deaf patients was lower in the right superior temporal gyrus, both middle temporal gyri, left inferior temporal gyrus, right inferior lobulus parietalis, right posterior cingulate gyrus, and left insular cortex than that of the control subjects. 3DSRT data also revealed significantly decreased glucose metabolism in both primary auditory cortices of the postlingually deaf patients. Conclusion: SPM and 3DSRT analyses indicated that glucose metabolism decreased in the primary auditory cortex of the postlingually deaf patients. The previous results of PET studies were confirmed, and our method involving 3DSRT has proved to be useful.

Differences in cerebral perfusion according to phenotypes of essential tremor: brain perfusion SPECT study using SPM analysis

Essential tremor (ET) is one of the most common movement disorders. However, few studies regarding the differences of pathophysiology according to phenotypes of ET have been reported. We investigated whether a functional difference occurs between ET with only a limb tremor (L-ET) and ET with only a head tremor (H-ET). We recruited 13 patients with L-ET, 10 patients with H-ET, and 33 healthy subjects. We compared the severity of tremor symptoms using the Fahn-Tolosa-Marin rating scale (FTM) to compare L-ET with H-ET. All subjects underwent magnetic resonance imaging and perfusion SPECT of the brain. The total score of FTM was significantly higher in the L-ET than in the H-ET. However, Part A in FTM did not show significant differences between the two ET groups. A brain perfusion SPECT analysis demonstrated no significant difference between L-ET and H-ET, but a regional perfusion of subjects with ET compared with healthy subjects showed hypoperfusion in the insular, cingulate gyrus, frontal lobe, and cerebellum. In conclusion, we suggested that cerebellar dysfunction might be involved in the pathogenesis of ET. In addition, we assumed that ET has the same pathogenesis in the origin of the disease, regardless of the clinical difference of ET.

Hypometabolism in PiB-positive, population-based, cognitively normal subjects with and without APOE-ɛ4

Pittsburgh compound B (PiB) accumulation occurs in about a third of cognitively normal (CN) subjects. The relationship of neurodegenerative biomarkers, namely FDG PET, and PiB positivity in CN subjects is not well understood. We hypothesized that subtle hypometabolism may occur in close temporal association with the early findings of PiB positivity. Therefore, we assessed hypometabolism in different stages of PiB positivity in CN subjects and related it to APOE status. 617 CN subjects in the Mayo Clinic Study of Aging were analyzed. We used two methods to identify any hypometabolic changes in PiB positive subjects. First, we used penalized logistic regression and cross-validation to develop a parsimonious multivariable region of interest model of “optimal” cortical brain regions of hypometabolism associated with PiB positivity. This method was first validated in our CN and AD populations and then employed in CN PiB negative and positive subjects. Second, we used a voxel-wise approach (SPM) to look at hypometabolism in various PiB-value subsets (dose-finding approach) namely those CN subjects with PiB values < 1.4 (n=351), >1.4 to 1.48(n=66), >1.48 to 1.73(n=66), >1.73 to 205(n=66), and >2.05(n=66). In subjects with PiB < 1.4, APOE -vs+ were compared for metabolic differences. Our penalized logistic regression model demonstrated hypometabolism in signature AD regions, namely the angular gyrus and posterior cingulate, in a cross-validated multivariable ROI model (AUC=0.65) in the CN PiB positive subjects. SPM analysis demonstrated a trend (non-FDR, P=0.005) for hypometabolism in these same regions beginning at the 1.48–1.73 PiB-value subset that became most significant in these regions but with additional, more diffuse cortical regional hypometabolism in the >2.05 subset (non-FDR, P=0.005). (Figure 1a) No hypometabolism was seen in APOE positive subjects (PiB <1.4) as compared to negatives at this same significance level (p=0.005).(Figure 1b) Hypometabolism in PiB positive, CN subjects in AD-signature cortical regions was seen at low levels of PiB positivity suggesting that neurodegeneration and related hypometabolism occurs early in the amyloid deposition process. No independent effect of APOE e4 carriage alone on hypometabolism was seen, although APOE e4 carriage was associated with greater PiB positivity. Pattern of hypometabolism seen in CN PiB positive subjects vs. CN PiB negative subjects (a) and APOE+ vs – PiB negative subjects (b) by SPM analysis.

Groupwise whole-brain parcellation from resting-state fMRI data for network node identification

In this paper, we present a groupwise graph-theory-based parcellation approach to define nodes for network analysis. The application of network-theory-based analysis to extend the utility of functional MRI has recently received increased attention. Such analyses require first and foremost a reasonable definition of a set of nodes as input to the network analysis. To date many applications have used existing atlases based on cytoarchitecture, task-based fMRI activations, or anatomic delineations. A potential pitfall in using such atlases is that the mean timecourse of a node may not represent any of the constituent timecourses if different functional areas are included within a single node. The proposed approach involves a groupwise optimization that ensures functional homogeneity within each subunit and that these definitions are consistent at the group level. Parcellation reproducibility of each subunit is computed across multiple groups of healthy volunteers and is demonstrated to be high. Issues related to the selection of appropriate number of nodes in the brain are considered. Within typical parameters of fMRI resolution, parcellation results are shown for a total of 100, 200, and 300 subunits. Such parcellations may ultimately serve as a functional atlas for fMRI and as such three atlases at the 100-, 200- and 300-parcellation levels derived from 79 healthy normal volunteers are made freely available online along with tools to interface this atlas with SPM, BioImage Suite and other analysis packages.

Assessment of Early Phase $^{18}{\rm F}$-FP-CIT PET as an Alternative Method of FDG PET for Voxel Based Statistical Analysis: Application for Parkinson's Disease Rat Model

18F -FP-CIT PET image was useful for diagnosis of Parkinson's disease (PD). Although spatial normalization step is necessary in SPM analysis, it was difficult to apply the spatial normalization on 18F-FP-CIT PET due to the lack of reference for spatial normalization. Therefore, additional data acquisition such as MRI or FDG PET scans is needed. In this study, we developed the voxel based statistical analysis method for 18F-FP-CIT PET using early phase of 18F-FP-CIT. 18F-FP-CIT PET data was acquired from 7 normal and 1 PD model rat brain. Emission PET data was collected for 1 h at the start of 1 mCi of 18F-FP-CIT. We used the early phase uptake image (from 0 to 1200 s) including perfusion phase as referential information for spatial normalization. Additionally, 18F-FDG PET was acquired as referential data to validate the substitution of 18F-FP-CIT. To validate early phase 18F-FP-CIT PET data for spatial normalization, correlation coefficient between early phase 18F-FP-CIT and 18F-FDG were assessed. Using our proposed method, SPM for 18F-FP-CIT PET was successfully implemented. Early phase 18F-FP-CIT PET corresponding early phase and 18F-FDG PET were highly correlated. When we applied our developed method for the comparison between normal and PD, we can identify the difference of 18F -FP-CIT between the normal and PD in the striatum (P 0). The SPM method for 18F -FP-CIT PET data could provide high localization accuracy in PD analysis. This method may be useful for assessment of PD.