The use of individual-based FDG-PET volume of interest in predicting conversion from mild cognitive impairment to dementia.

BACKGROUND: Based on a longitudinal cohort design, the aim of this study was to investigate whether individual-based 18F fluorodeoxyglucose positron emission tomography (18F-FDG-PET) regional signals can predict dementia conversion in patients with mild cognitive impairment (MCI). METHODS: We included 44 MCI converters (MCI-C), 38 non-converters (MCI-NC), 42 patients with Alzheimer's disease with dementia, and 40 cognitively normal controls. Data from annual cognitive measurements, 3D T1 magnetic resonance imaging (MRI) scans, and 18F-FDG-PET scans were used for outcome analysis. An individual-based FDG-PET approach was applied using seven volumes of interest (VOIs), Z transformed using a normal FDG-PET template. Hypometabolism was defined as a Z score < -2 of regional standard uptake value ratio. For the longitudinal cognitive test scores, generalized estimating equations were used. A linear mixed-effects model was used to compare the temporal impact of cortical hypometabolism and cortical thickness degeneration. RESULTS: The clinical follow-up period was 6.6 ± 3.8 years (range 3.1 to 16.0 years). The trend of cognitive decline could differentiate MCI-C from MCI-NC after 3 years of follow-up. In the baseline 18F-FDG-PET scan of the patients with MCI, medial temporal lobe (MTL; 94.7% sensitivity, 80.5% specificity) and posterior cingulate cortex (PCC; 89.5% sensitivity, 73.1% specificity) hypometabolism predicted conversion with high accuracy. 18F-FDG-PET hypometabolism preceded dementia conversion at an interval of 3.70 ± 1.68 years and was earlier than volumetric changes, with the exception of the MTL. CONCLUSIONS: Our finding supports the use of individual-based 18F-FDG-PET analysis to predict MCI conversion to dementia. Reduced FDG-PET metabolism in the MTL and PCC were strongly associated with future cognitive decline in the MCI-C group. Changes in 18F-FDG-PET occurred 1 to 8 years prior to conversion to dementia. Progressive hypometabolism in the PCC, precuneus and lateral temporal lobe, but not MTL, preceded MRI findings at the MCI stage.

Impact of Amyloid Pathology in Mild Cognitive Impairment Subjects: The Longitudinal Cognition and Surface Morphometry Data.

The amyloid framework forms the central medical theory related to Alzheimer disease (AD), and the in vivo demonstration of amyloid positivity is essential for diagnosing AD. On the basis of a longitudinal cohort design, the study investigated clinical progressive patterns by obtaining cognitive and structural measurements from a group of patients with amnestic mild cognitive impairment (MCI); the measurements were classified by the positivity (Aß+) or absence (Aß-) of the amyloid biomarker. We enrolled 185 patients (64 controls, 121 patients with MCI). The patients with MCI were classified into two groups on the basis of their [18F]flubetaben or [18F]florbetapir amyloid positron-emission tomography scan (Aß+ vs. Aß-, 67 vs. 54 patients) results. Data from annual cognitive measurements and three-dimensional T1 magnetic resonance imaging scans were used for between-group comparisons. To obtain longitudinal cognitive test scores, generalized estimating equations were applied. A linear mixed effects model was used to compare the time effect of cortical thickness degeneration. The cognitive decline trajectory of the Aß+ group was obvious, whereas the Aß- and control groups did not exhibit a noticeable decline over time. The group effects of cortical thickness indicated decreased entorhinal cortex in the Aß+ group and supramarginal gyrus in the Aß- group. The topology of neurodegeneration in the Aß- group was emphasized in posterior cortical regions. A comparison of the changes in the Aß+ and Aß- groups over time revealed a higher rate of cortical thickness decline in the Aß+ group than in the Aß- group in the default mode network. The Aß+ and Aß- groups experienced different APOE ε4 effects. For cortical-cognitive correlations, the regions associated with cognitive decline in the Aß+ group were mainly localized in the perisylvian and anterior cingulate regions. By contrast, the degenerative topography of Aß- MCI was scattered. The memory learning curves, cognitive decline patterns, and cortical degeneration topographies of the two MCI groups were revealed to be different, suggesting a difference in pathophysiology. Longitudinal analysis may help to differentiate between these two MCI groups if biomarker access is unavailable in clinical settings.

Dynamic contrast-enhanced magnetic resonance imaging in correlation with tongue cancer stages.

BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) plays a significant role in tumor stage as it can be used to measure tissue perfusion and permeability of tumors. PURPOSE: To investigate the relationships between both quantitative and semi-quantitative variables obtained from DCE-MRI and tongue cancer stages. MATERIAL AND METHODS: Mean values of Ktrans, enhancement ratio (ER), wash-in slope (slope), and the 95th percentile (95%) values of the distribution for Ktrans, ER, and slope values (Ktrans (95%), ER (95%), and slope (95%), respectively) were calculated for 53 patients with tongue cancers (American Joint Committee on Cancer 8th Edition stage group: 10 in stages I and II, 14 in stage III, 21 in stage IVa, and eight in stage IVb as determined by histopathologic assessment). The relationship between tumor staging and each of the six DCE-MRI parameters was assessed separately using ordinal logistic regression. RESULTS: The logistic regression analysis revealed that both mean and 95th percentile values of Ktrans were significantly and positively correlated with tongue cancer stage (P < 0.01). More aggressive tumor stages had larger kinetic parameter. Moreover, the semi-quantitative parameters, such as ER (95%) and slope (95%), may be more significant predictors for evaluating tongue cancer stages than the mean ER and mean slope. CONCLUSION: Both quantitative and semi-quantitative imaging biomarkers are useful for evaluating the stages of tongue cancer, and the indices obtained from DCE-MRI were positively correlated with the tumor stages. These parameters have the potential to non-invasively evaluate the stages of tongue cancer in the clinical setting.

Genetic effect of MTHFR C677T polymorphism on the structural covariance network and white-matter integrity in Alzheimer's disease.

The 677 C to T transition in the MTHFR gene is a genetic determinant for hyperhomocysteinemia. We investigated whether this polymorphism modulates gray matter (GM) structural covariance networks independently of white-matter integrity in patients with Alzheimer's disease (AD). GM structural covariance networks were constructed by 3D T1-magnetic resonance imaging and seed-based analysis. The patients were divided into two genotype groups: C homozygotes (n = 73) and T carriers (n = 62). Using diffusion tensor imaging and white-matter parcellation, 11 fiber bundle integrities were compared between the two genotype groups. Cognitive test scores were the major outcome factors. The T carriers had higher homocysteine levels, lower posterior cingulate cortex GM volume, and more clusters in the dorsal medial lobe subsystem showing stronger covariance strength. Both posterior cingulate cortex seed and interconnected peak cluster volumes predicted cognitive test scores, especially in the T carriers. There were no between-group differences in fiber tract diffusion parameters. The MTHFR 677T polymorphism modulates posterior cingulate cortex-anchored structural covariance strength independently of white matter integrities. Hum Brain Mapp 38:3039-3051, 2017. © 2017 The Authors Human Brain Mapping Published Wiley by Periodicals, Inc.

Genetic effect of interleukin-1 beta (C-511T) polymorphism on the structural covariance network and white matter integrity in Alzheimer's disease.

BACKGROUND: Inflammatory processes play a pivotal role in the degenerative process of Alzheimer's disease. In humans, a biallelic (C/T) polymorphism in the promoter region (position-511) (rs16944) of the interleukin-1 beta gene has been significantly associated with differences in the secretory capacity of interleukin-1 beta. In this study, we investigated whether this functional polymorphism mediates the brain networks in patients with Alzheimer's disease. METHODS: We enrolled a total of 135 patients with Alzheimer's disease (65 males, 70 females), and investigated their gray matter structural covariance networks using 3D T1 magnetic resonance imaging and their white matter macro-structural integrities using fractional anisotropy. The patients were classified into two genotype groups: C-carriers (n = 108) and TT-carriers (n = 27), and the structural covariance networks were constructed using seed-based analysis focusing on the default mode network medial temporal or dorsal medial subsystem, salience network and executive control network. Neurobehavioral scores were used as the major outcome factors for clinical correlations. RESULTS: There were no differences between the two genotype groups in the cognitive test scores, seed, or peak cluster volumes and white matter fractional anisotropy. The covariance strength showing C-carriers > TT-carriers was the entorhinal-cingulum axis. There were two peak clusters (Brodmann 6 and 10) in the salience network and four peak clusters (superior prefrontal, precentral, fusiform, and temporal) in the executive control network that showed C-carriers < TT-carriers in covariance strength. The salience network and executive control network peak clusters in the TT group and the default mode network peak clusters in the C-carriers strongly predicted the cognitive test scores. CONCLUSIONS: Interleukin-1 beta C-511 T polymorphism modulates the structural covariance strength on the anterior brain network and entorhinal-interconnected network which were independent of the white matter tract integrity. Depending on the specific C-511 T genotype, different network clusters could predict the cognitive tests.

Effects of Homocysteine on white matter diffusion parameters in Alzheimer's disease.

BACKGROUND: The clinical features of Alzheimer's disease (AD) are related to brain network degeneration, and hyperhomocysteinemia is related to greater white matter hyperintensities. We investigated the changes in four diffusion tensor imaging parameters in the white matter of patients with early stage AD, examined their associations with homocysteine level, and tested the clinical significance of the diffusion tensor imaging parameters and homocysteine level in correlation analysis with cognitive test scores. METHODS: We enrolled 132 patients with AD and analyzed white matter (WM) macrostructural changes using diffusion tensor neuroimaging parameters including fractional anisotropy (FA), mean diffusion (MD), axial diffusivity (axial-D) and radial diffusivity (RD). Two neuroimaging post-processing analyses were performed to provide complementary data. First, we calculated 11 major bundle microstructural integrities using a WM parcellation algorithm, and correlated them with serum homocysteine levels to explore whether the fiber bundles were affected by homocysteine. Second, we used tract-based spatial statistics to explore the anatomical regions associated with homocysteine levels. Changes in cognitive test scores caused by homocysteine served as the major outcome factor. RESULTS: The results suggested that homocysteine levels did not have a direct impact on cross-sectional cognitive test scores, but that they were inversely correlated with renal function, B12 and folate levels. Topographies showing independent correlations with homocysteine in FA and MD were more diffusely located compared to the posterior brain regions in axial-D and RD. In the association bundle analysis, homocysteine levels were significantly correlated with the four diffusion parameters even after correcting for confounders, however no association between homocysteine and WM to predict cognitive outcomes was established. CONCLUSIONS: In our patients with AD, homocysteine levels were associated with renal dysfunction and decreased levels of vitamin B12 and folate, all of which require clinical attention as they may have been associated with impaired WM microstructural integrity and modulated cognitive performance in cross-sectional observations.

Interictal serum brain-derived neurotrophic factor level reflects white matter integrity, epilepsy severity, and cognitive dysfunction in chronic temporal lobe epilepsy.

OBJECTIVE: Most patients with temporal lobe epilepsy (TLE) have epileptic foci originating from the medial temporal lobe, particularly the hippocampus. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin growth factor mainly expressed in the hippocampus, though it is not known whether the circulating level of BDNF reflects cognitive performance or white matter structural changes in chronic TLE. METHODS: Thirty-four patients with TLE and 22 healthy controls were enrolled for standardized cognitive tests, diffusion tensor imaging, and serum BDNF measurement. The patients were further divided into a subgroup with unilateral TLE (n=23) and a subgroup with bilateral TLE (n=11) for clinical and neuroimaging comparisons. RESULTS: There were significantly lower BDNF levels in the patients with TLE compared with the controls, with significance contributed mainly from the subgroup with bilateral TLE, which also had more frequent seizures. The BDNF levels correlated with epilepsy duration (σ=-0.355; p=0.040) and fractional anisotropy (FA) in the left temporal lobe, left thalamus, and right hippocampus. Using a regression model, BDNF level predicted verbal memory score. Further, design fluency scores were predicted by serum BDNF level via the interactions with left temporal FA. CONCLUSIONS: Serum BDNF levels reflected longer epilepsy duration, impaired white matter integrity, and poor cognitive function in patients with chronic TLE.

Altered neurochemical metabolites in Alzheimer's disease patients with unawareness of deficits.

BACKGROUND: Unawareness of deficits is common and is associated with poor outcomes in Alzheimer's disease (AD); however, little is known about correlated neurobiochemical changes. METHODS: Proton magnetic resonance spectroscopy was used to examine neurobiochemical correlates of unawareness of deficits as assessed by the Dementia Deficit Scale in 36 patients with AD. Magnetic resonance spectroscopy spectra were acquired from the anterior cingulate area and right orbitofrontal area. Concentrations of N-acetyl-aspartate (NAA), total creatine, and other neurometabolites were calculated. RESULTS: Nineteen (52.8%) participants had relative unawareness of deficits. This condition was negatively correlated with NAA/creatine in the anterior cingulate area (ß = -0.36, p = 0.025) and positively correlated with NAA/creatine in the right orbitofrontal area (ß = 0.41, p = 0.009) after controlling for dementia severity. CONCLUSIONS: These findings suggest unawareness of deficits in AD was associated with the altered neurochemical metabolites in the anterior cingulate area and right orbitofrontal area. However, the two areas might have opposite neuronal functions in unawareness of deficits.

Analyzed outcome for embolization of hepatic carcinoma by C-arm angiographic computed tomography.

PURPOSE: This study evaluated and monitored the outcome of angiographic embolization of hepatic carcinoma by real-time C-arm angiographic computed tomography under number of tumors, size of tumors, and patient's age.METHODS AND MARTIALS: In total, 142 patients underwent angiographic embolization of hepatic carcinoma. The control group, 71 patients, underwent conventional angiographic (CA) embolization of hepatic carcinoma. The experimental group, 71 patients, underwent C-arm angiographic computed tomography (CCT) embolization of hepatic carcinoma. The numbers of angiographic embolization, number of tumors, size of tumors, and patients ages were recorded for comparisons between groups by analysis of variance (ANOVA) with cross-interaction and the chi-square test (cross table). RESULTS: The age ranges were 20-84 and 35-84 years old for the experimental and control groups respectively. Average number of angiographic embolizations of hepatic carcinomas were 2.63 ± 1.84 and 5.32 ± 2.01 for the experimental and control groups. The number of angiographic embolizations under number of tumors, size of tumors, and patients ages between groups were significantly different (P< 0.05). The effective analyses of transcatheter arterial chemoembolization (TACE) by CCT were significant by chi-square test (P< 0.05) under ⩽ 3 cm and patients aged ⩽ 60. CONCLUSION: The main advantage by CCT for undergoing TACE under tumor size smaller than 3 cm and numbers of tumor smaller 3 times were more significantly effective than those by CA. The CCT combined with TACE had high potentially reduced numbers of undergoing TACE.

Diffusion-weighted imaging improves prediction in cognitive outcome and clinical phases in patients with carbon monoxide intoxication.

INTRODUCTION: Changes in apparent diffusion coefficient (ADC) values often reflect tissue injury. Use of ADC as a surrogate marker to assess clinical phases has not been systemically applied in patients with carbon monoxide (CO) intoxication. METHODS: Fifty-nine magnetic resonance imaging scans and cognitive evaluations were performed in 47 patients with CO intoxication and compared with 22 sex- and age-matched controls. The patients were further classified into three groups based on the clinical phases, namely, acute (within 2 weeks), delayed neuropsychiatric (2 weeks to 6 months), and chronic (>1 year) groups. The ADC values were measured in 16 regions of interests (ROIs) and correlated with cognitive test scores. RESULTS: Among the 59 evaluations, 15 were in the acute, 26 in the delayed neuropsychiatric, and 18 in the chronic groups. Among the ROIs, significant elevations of ADC values were found in the corpus callosum and globus pallidus in all three CO phases compared with the controls, and the ADC values were highest in the chronic phases. In contrast, the ADC values in peripheral gray matter and white matter were highest in the delayed neuropsychiatric group. Both globus pallidus and corpus callosum ADC values correlated with multiple cognitive test scores. CONCLUSION: Using ADC as a surrogate marker, the globus pallidus and corpus callosum can be considered to be two vulnerable structures in the gray and white matter. Significant differences between ADC values correlated well with clinical phase and cognitive performance.

Neuropsychiatric Symptoms and Caregiver Stress in Parkinson's Disease with Cognitive Impairment, Alzheimer's Disease, and Frontotemporal Dementia.

BACKGROUND: A better understanding of factors associated with caregiver burden might facilitate the construction of coping strategies to improve their clinical outcomes and the comprehensive care model for dementia. OBJECTIVE: To investigate the cognitive and neuropsychiatric domains that contribute to caregiver burden in three types of neurodegenerative disorders: Parkinson's disease (PD), Alzheimer's disease (AD), and frontotemporal disease (FTD). METHODS: Eight hundred and fourteen patients and their caregivers were invited to participate; among them, 235 had PD with cognitive impairment; 429 had AD, and 150 had FTD. The evaluation protocol included the Neuropsychiatric Inventory (NPI), the Mini-Mental State Examination, the Chinese Version Verbal Learning Test, the modified Trail Making Test B, semantic fluency, and a geriatric depression score. Statistical comparisons of the cognitive tests, NPI total scores, and caregiver burden among the three diagnosed types of dementia, matched for a Clinical Dementia Rating (CDR) of 0.5 or 1, were performed, and multivariate linear regression models were used to evaluate the parameter significance. RESULTS: Caregivers for patients with PD and FTD showed significant burden increments when the CDR scores changes from 0.5 to 1. For CDR = 0.5, the PD group had significantly lower caregiver burdens than the AD group, but the NPI total scores were significantly higher. Factors related to caregiver burden were the presence of delusion among all diagnosis groups, while the impact of NPI total scores related to caregiver burden was the highest in FTD, followed by AD and PD. CONCLUSIONS: At the mild to moderate stages, our results suggested different degrees of significance in terms of the cognitive test scores or NPI subdomains for predicting caregiver stress among the three types of dementia.

Association of Cognition and Brain Reserve in Aging and Glymphatic Function Using Diffusion Tensor Image-along the Perivascular Space (DTI-ALPS).

The glymphatic system is a fluid-clearance pathway that clears cerebral waste products, and its dysfunction has been associated with protein aggregation diseases such as Alzheimer's disease. To understand how the glymphatic system changes with aging, we enrolled 433 cognitive unimpaired participants (236 women and 197 men, 13-88 years) and evaluated the glymphatic function by calculating diffusion tensor imaging analysis along the perivascular space (ALPS) index and explored how the ALPS index is associated with cortical atrophy and cognitive decline in older people. We found a significant inverse correlation between ALPS index and age (ρ = -0.45, p < 0.001), with a peak value in people in their thirties. A higher ALPS index indicated a better cortical reserve in regions coincided with the default mode network. Declines in mental manipulation and short-term memory performance in the older participants were associated with a lower ALPS index and cortical atrophy in the amygdala, anterior and posterior cingulate, thalamus and middle frontal regions. Our findings highlight that the ALPS index could be used to evaluate brain reserve and cognitive reserve in older people.

Clinical significance of fractional anisotropy in cerebral white matter regional vulnerability caused by carbon monoxide poisoning: A systematic review and meta-analysis.

Carbon monoxide poisoning (COP) can lead to various cerebral white matter (WM) lesions across different disease phases and clinical manifestations, and fractional anisotropy (FA) of diffusion tensor imaging has been widely applied to investigate WM injury in these patients. Here we conducted a systematic review and meta-analysis to investigate the utility of FA in evaluating the regional vulnerability of WM injury caused by COP and explore differences between different disease phases and patient subtypes. We systematically searched PubMed, Medline, Scopus and reference lists of appropriate publications to identify relevant studies. Eight studies with 217 patients with COP and 207 healthy controls (HCs) were included. Eight regions of interest were available to investigate regional vulnerability. The results showed the most significant decrease in FA in orbitofrontal subcortical regions. Comparisons of different disease phases revealed lower FA in the centrum semiovale and corpus callosum in the acute phase, while in the chronic phase, only FA in the centrum semiovale remained significantly decreased. Analysis of different patient subtypes showed that the FA values in the splenium of the corpus callosum were significantly decreased in the patients with delayed neurologic sequelae (DNS) but not in the mixed population (with and without DNS). In conclusion, this meta-analysis highlights the frontal-subcortical regional vulnerability in COP. FA changes in the corpus callosum across different disease phases reflect alterations in underlying microstructures. Extended corpus callosum injury involving the splenium could be an imaging biomarker of the occurrence of DNS.

Clinical significance of serological biomarkers and neuropsychological performances in patients with temporal lobe epilepsy.

BACKGROUND: Temporal lobe epilepsy (TLE) is a common form of focal epilepsy. Serum biomarkers to predict cognitive performance in TLE patients without psychiatric comorbidities and the link with gray matter (GM) atrophy have not been fully explored. METHODS: Thirty-four patients with TLE and 34 sex - and age-matched controls were enrolled for standardized cognitive tests, neuroimaging studies as well as measurements of serum levels of heat shock protein 70 (HSP70), S100ß protein (S100ßP), neuronal specific enolase (NSE), plasma nuclear and mitochondrial DNA levels. RESULTS: Compared with the controls, the patients with TLE had poorer cognitive performances and higher HSP70 and S100ßP levels (p < 0.01). The patients with higher frequencies of seizures had higher levels of HSP70, NSE and S100ßP (p < 0.01). Serum HSP70 level correlated positively with duration of epilepsy (σ = 0.413, p < 0.01), and inversely with memory scores in the late registration (σ = -0.276, p = 0.01) and early recall score (σ = -0.304, p = 0.007). Compared with the controls, gray matter atrophy in the hippocampal and parahippocampal areas, putamen, thalamus and supplementary motor areas were found in the patient group. The HSP70 levels showed an inverse correlation with hippocampal volume (R square = 0.22, p = 0.007) after controlling for the effect of age. CONCLUSIONS: Our results suggest that serum biomarkers were predictive of higher frequencies of seizures in the TLE group. HSP70 may be considered to be a stress biomarker in patients with TLE in that it correlated inversely with memory scores and hippocampal volume. In addition, the symmetric extratemporal atrophic patterns may be related to damage of neuronal networks and epileptogenesis in TLE.

Clinical significance of the pallidoreticular pathway in patients with carbon monoxide intoxication.

Whereas globus pallidus lesions resulting from carbon monoxide intoxication have been extensively described in the literature, the clinical significance of pallidoreticular lesions has rarely been mentioned. This study incorporated information from functional and structural imaging to explore the correlations of pallidoreticular lesions with parkinsonian features and neurobehavioural performance. Twenty-five patients (11 males) with globus pallidus lesions after carbon monoxide intoxication and 25 age- and sex-matched controls were enrolled for detailed neurological examinations, cognitive testing, susceptibility weighted imaging, diffusion tensor imaging and 99mTc-TRODAT-1 single photon emission computed tomography. The post-processing analysis of the neuroimaging included voxel-based morphometry to assess the regional atrophy, tract-based spatial statistics related to white matter involvement, tractography to investigate the rostral and caudal projections from the midbrain level and specific uptake ratios of 99mTc-TRODAT-1 for presynaptic dopaminergic transporter activity. In susceptibility weighted imaging, low-intensity pallidoreticular lesions were detected from the minimal-intensity projections, which were visible in only 7.7% of the T(1)-weighted images and 15.4% of the T(2)-weighted images, whereas inhomogeneous intensities were detected in the globus pallidus. The patients were further divided into two subgroups based on the presence (n = 13) or absence (n = 12) of pallidoreticular lesions. The patients with pallidoreticular lesions showed increased parkinsonian features, poorer performances on the neuropsychiatric tests, lower 99mTc-TRODAT-1 availability in both the caudate and the putamen and greater atrophy of the thalamus, posterior corpus callosum, cerebral peduncle and white matter surrounding the globus pallidus compared to those without pallidoreticular lesions. The tractography results obtained with seed regions of interest in the substantia nigra showed rostral projections to the supplementary motor cortex and anterior cingulate cortex via the globus pallidus; the two pathways were distinct but ran in parallel, caudal to the level of the globus pallidus. In conclusion, the presence of pallidoreticular lesions after carbon monoxide intoxication indicates a poorer cognitive state, which is associated with extensive grey and white matter damage in addition to the damage to the nigra-striatal neuronal networks. The presence of parkinsonian features may be related to pallidal and presynaptic dopaminergic dysfunction. The sensitivity for detecting pallidoreticular lesions can be greatly improved by using susceptibility weighted imaging compared with conventional imaging.

TRICKS magnetic resonance angiography at 3-tesla for assessing whole lower extremity vascular tree in patients with high-grade critical limb ischemia: DSA and TASC II guidelines correlations.

The entire vascular tree of 58 lower extremities with high-grade critical limb ischemia (CLI) was assessed with three-station time resolved imaging of contrast kinetics (TRICKS) magnetic resonance angiography (T-MRA) and correlated with digital subtraction angiography (DSA) examinations and Trans-Atlantic Inter-Society Consensus II (TASC II) guidelines. Kappa (κ) statistics were utilized to evaluate the agreement of stenosis scores (5-point scale; 0 normal to 4 occlusion) based on T-MRA and DSA. With DSA as the standard, significant stenosis instances (stenosis score ≥2) among vascular segments were compared. The κ-statistics of image quality (4-point scale; 1 nondiagnostic to 4 excellent) of T-MRA and TASC II classification assessed by a radiologist and a vascular surgeon were also evaluated. Among 870 vascular segments, excellent agreement was observed between T-MRA and DSA (mean κ = 0.883) in revealing stenosis (mean stenosis score, 2.1 ± 1.3 versus 2.0 ± 1.3). T-MRA harbored overall high sensitivity (99.5%), specificity (93.6%), positive predictive value (95.4%), negative predictive value (99.6%), and accuracy (97.7%) in depicting significant stenosis. Excellent interobserver agreement (mean κ = 0.818) of superb image quality (mean score = 3.5-3.6) of T-MRA and outstanding agreement of TASC II classification of aortoiliac and femoral-popliteal lesions (κ = 0.912-0.917) between two raters further verified the clinical feasibility of T-MRA for treatment planning.

Quantifying liver cirrhosis by extracting significant features from MRI T2 image.

Most patients with liver cirrhosis must undergo a series of clinical examinations, including ultrasound imaging, liver biopsy, and blood tests. However, the quantification of liver cirrhosis by extracting significant features from a T2-weighted magnetic resonance image (MRI) provides useful diagnostic information in clinical tests. Sixty-two subjects were randomly selected to participate in this retrospective analysis with assigned to experimental and control groups. The T2-weighted MRI was obtained and to them dynamic adjusted gray levels. The extracted features of the image were standard deviation (SD), mean, and entropy of pixel intensity in the region of interest (ROI). The receiver operator characteristic (ROC) curve, 95% confidence intervals, and kappa statistics were used to test the significance and agreement. The analysis of area under ROC shows that SD, mean, and entropy in the ROI were significant between the experimental group and the control group. Smaller values of SD, mean, and entropy were associated with a higher probability of liver cirrhosis. The agreements between the extracted features and diagnostic results were shown significantly (P < 0.001). In this investigation, quantitative features of SD, mean, and entropy in the ROI were successfully computed by the dynamic gray level scaling of T2-weighted MRI with high accuracy.

Pallidoreticular lesion in carbon monoxide intoxication by gradient echo: report of a case with parkinsonism features and review of the literature.

PURPOSE: Pallidoreticular damage was defined by lesions involving both the pallidum and the substantia nigra and was only reported in four cases after CO intoxication. CASE REPORT: We report a patient with initial consciousness disturbances followed by parkinsonian features after carbon monoxide intoxication. The unique features in this patient included primary globus pallidus hemorrhage followed by delayed hemorrhage in pallidoreticular topography demonstrated by T1- and T2-weighted imaging. In the follow-up study 7 months later, the patient still presented with parkinsonism features and executive dysfunction while the pallidoreticular signal was only visible by gradient echo sequences but not the other MR conventional sequences. Hypometabolism in the frontal and basal ganglion regions were evident from 99mTc-TRODAT-1 study and partial responsiveness to levodopa in alleviating parkinsonian features was considered. CONCLUSION: This case highlights the delayed development of pallidoreticular damages and its linkage in modulating prefrontal-subcortical neuronal circuits.

Montreal cognitive assessment in assessing clinical severity and white matter hyperintensity in Alzheimer's disease with normal control comparison.

PURPOSE: Use Taiwanese version of the Montreal Cognitive Assessment (MoCA) in evaluating patients in different stages of Alzheimer's disease (AD) and correlate with white matter change. METHODS: Ninety-seven normal controls (NC), 52 very-mild AD (clinical dementia rating [CDR] = 0.5), 48 mild AD (CDR = 1) and 38 moderate AD (CDR = 2) patients were enrolled for the MoCA, Mini- Mental State Examination (MMSE) and the Cognitive Assessment Screening Instrument (CASI). White matter hyperintensities (WMHs) on brain MRI were visually rated and classified as deep or periventricular WMHs. RESULTS: In NC group, education (ß = 0.326) but not age (ß = -0.183, p = 0.069), was significantly related to MoCA score. However, while we added two points to the AD patients with less than 6 years education, the effects of education disappeared as compared with those of 7 years of education. For all educational levels, the cutoff value of MoCA for very-mild AD was 22/23 (sensitivity = 82.7%, specificity = 87.6%). No significant differences were found in the areas under the curves that differentiated NC from the patients with AD for MoCA and MMSE (differences = 0.008, p = 0.490), or for MoCA and CASI (differences = 0.023, p = 0.082). Total WMHs, frontal deep and periventricular WMHs were inversely correlated with the attention and delayed-recall subdomain. CONCLUSION: The MoCA is a good clinical tool for screening very-mild stage AD if the educational effects are carefully considered. The correlation between the executive subdomains with the frontal WMHs also makes it a useful tool for detecting subtle WMHs.

Functional Connectivity, Physical Activity, and Neurocognitive Performances in Patients with Vascular Cognitive Impairment, No Dementia.

BACKGROUND: Vascular Cognitive Impairment, No Dementia (VCIND) is a key stage at which early intervention will delay or prevent dementia. The pathophysiology of VCIND posits that a lesion in a single location in the brain has the ability to disrupt brain networks, and the subsequent abnormal Functional Connectivity (FC) of brain networks leads to deficits in corresponding neurobehavioral domains. In this study, we tested the hypothesis that disrupted anterior cingulate cortex and striatal networks mediated the effects of Physical Activity (PA) on neurobehavioral function. METHODS: In 27 patients with VCIND, FC within the brain networks and neurobehavioral dysfunction were assessed. The relationship between the cognitive scores, FC, and PA was studied. The Fitbit Charge 2 was used to measure step counts, distance, and calories burned. In patients with VCIND, a cross-sectional Spearman's correlation to analyze the relationship among patient-level measures of PA, cognitive function scores, and FC strength within the brain networks. RESULTS: Average step counts and average distance were associated with Trail Making Test B (TMB) time to completion (seconds) and Instrumental Activities of Daily Living (IADL) score (P < 0.05). The average calories burned were associated with IADL score (P = 0.009). The FC within the brain networks anchored by left caudal Anterior Cingulate Cortex (ACC) seeds (x= -5, y= 0, z= 36) and (x= -5, y= -10, z= 47) were positively correlated with average step counts and average distance, were negatively correlated with TMB time to completion (seconds), and were positively correlated with IADL score (P < 0.05). The FC within the brain networks anchored by left subgenual ACC seed (x= -5, y= 25, z= -10) were negatively correlated with average step counts and average distance were positively correlated with TMB time to completion (seconds), and were negatively correlated with IADL score (P < 0.05). The FC within the striatal networks was positively correlated with average calories burned and IADL score (P < 0.05). CONCLUSION: FC within the brain networks anchored by caudal ACC seeds was positively correlated with more average step counts/average distance and better IADL score; negatively correlated with longer TMB time to completion (seconds), whereas FC of subgenual ACC seed was negatively correlated with the same parameters. FC within the brain networks anchored by putamen rather than caudate or pallidum was positively correlated with average calories burned and IADL score.