Multiparametric MRI-based fusion radiomics for predicting telomerase reverse transcriptase (TERT) promoter mutations and progression-free survival in glioblastoma: a multicentre study.

PURPOSE: This study evaluated the performance of multiparametric magnetic resonance imaging (MRI)-based fusion radiomics models (MMFRs) to predict telomerase reverse transcriptase (TERT) promoter mutation status and progression-free survival (PFS) in glioblastoma patients. METHODS: We retrospectively analysed 208 glioblastoma patients from two hospitals. Quantitative imaging features were extracted from each patient's T1-weighted, T1-weighted contrast-enhanced, and T2-weighted preoperative images. Using a coarse-to-fine feature selection strategy, four radiomics signature models were constructed based on the three MRI sequences and their combination for TERT promoter mutation status and PFS; model performance was subsequently evaluated. Subgroup analyses were performed by the radiomics signature of TERT promoter mutation status and PFS to distinguish patients who could benefit from prolonged temozolomide chemotherapy cycles. RESULTS: TERT promoter mutation status was best predicted by MMFR, with an area under the curve (AUC) of 0.816 and 0.812 for the training and internal validation sets, respectively. The external test set also achieved stable and optimal prediction results (AUC, 0.823). MMFR better predicted patient PFS compared with the single-sequence radiomics signature in the test set (C-index, 0.643 vs 0.561 vs 0.620 vs 0.628). Subgroup analyses showed that more than six cycles of postoperative temozolomide chemotherapy were associated with improved PFS for patients in class 2 (high TERT promoter mutation and high survival rates; HR, 0.222; 95% CI, 0.054 - 0.923; p = 0.025). CONCLUSION: MMFR is an effective method to predict TERT promoter mutations and PFS in patients with glioblastoma. Moreover, subgroup analysis could differentiate patients who may benefit from prolonged TMZ chemotherapy cycles.

Glioblastoma and Solitary Brain Metastasis: Differentiation by Integrating Demographic-MRI and Deep-Learning Radiomics Signatures.

BACKGROUND: Studies have shown that deep-learning radiomics (DLR) could help differentiate glioblastoma (GBM) from solitary brain metastasis (SBM), but whether integrating demographic-MRI and DLR features can more accurately distinguish GBM from SBM remains uncertain. PURPOSE: To construct and validate a demographic-MRI deep-learning radiomics nomogram (DDLRN) integrating demographic-MRI and DLR signatures to differentiate GBM from SBM preoperatively. STUDY TYPE: Retrospective. POPULATION: Two hundred and thirty-five patients with GBM (N = 115) or SBM (N = 120), randomly divided into a training cohort (90 GBM and 98 SBM) and a validation cohort (25 GBM and 22 SBM). FIELD STRENGTH/SEQUENCE: Axial T2-weighted fast spin-echo sequence (T2WI), T2-weighted fluid-attenuated inversion recovery sequence (T2-FLAIR), and contrast-enhanced T1-weighted spin-echo sequence (CE-T1WI) using 1.5-T and 3.0-T scanners. ASSESSMENT: The demographic-MRI signature was constructed with seven imaging features ("pool sign," "irregular ring sign," "regular ring sign," "intratumoral vessel sign," the ratio of the area of peritumoral edema to the enhanced tumor, the ratio of the lesion area on T2-FLAIR to CE-T1WI, and the tumor location) and demographic factors (age and sex). Based on multiparametric MRI, radiomics and deep-learning (DL) models, DLR signature, and DDLRN were developed and validated. STATISTICAL TESTS: The Mann-Whitney U test, Pearson test, least absolute shrinkage and selection operator, and support vector machine algorithm were applied for feature selection and construction of radiomics and DL models. RESULTS: DDLRN showed the best performance in differentiating GBM from SBM with area under the curves (AUCs) of 0.999 and 0.947 in the training and validation cohorts, respectively. Additionally, the DLR signature (AUC = 0.938) outperformed the radiomics and DL models, and the demographic-MRI signature (AUC = 0.775) was comparable to the T2-FLAIR radiomics and DL models in the validation cohort (AUC = 0.762 and 0.749, respectively). DATA CONCLUSION: DDLRN integrating demographic-MRI and DLR signatures showed excellent performance in differentiating GBM from SBM. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

A novel MRI feature, the cut green pepper sign, can help differentiate a suprasellar pilocytic astrocytoma from an adamantinomatous craniopharyngioma.

OBJECTIVE: There are no specific magnetic resonance imaging (MRI) features that distinguish pilocytic astrocytoma (PA) from adamantinomatous craniopharyngioma (ACP). In this study we compared the frequency of a novel enhancement characteristic on MRI (called the cut green pepper sign) in PA and ACP. METHODS: Consecutive patients with PA (n = 24) and ACP (n = 36) in the suprasellar region were included in the analysis. The cut green pepper sign was evaluated on post-contrast T1WI images independently by 2 neuroradiologists who were unaware of the pathologic diagnosis. The frequency of cut green pepper sign in PA and ACP was compared with Fisher's exact test. RESULTS: The cut green pepper sign was identified in 50% (12/24) of patients with PA, and 5.6% (2/36) with ACP. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the cut green pepper sign for diagnosing PA were 50%, 94.4%, 85.7% and 73.9%, respectively. There was a statistically significant difference in the age of patients with PA with and without the cut green pepper sign (12.3 ± 9.2 years vs. 5.5 ± 4.4 years, p = 0.035). CONCLUSION: The novel cut green pepper sign can help distinguish suprasellar PA from ACP on MRI.

Clinical features and FLAIR radiomics nomogram for predicting functional outcomes after thrombolysis in ischaemic stroke.

Objective: We explored whether radiomics features extracted from diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) images can predict the clinical outcome of patients with acute ischaemic stroke. This study was conducted to investigate and validate a radiomics nomogram for predicting acute ischaemic stroke prognosis. Methods: A total of 257 patients with acute ischaemic stroke from three clinical centres were retrospectively assessed from February 2019 to July 2022. According to the modified Rankin scale (mRS) at 3 months, the patients were divided into a favourable outcome group (mRS of 0-2) and an unfavourable outcome group (mRS of 3-6). The high-throughput features from the regions of interest (ROIs) within the radiologist-drawn contour by AK software were extracted. We used two feature selection methods, minimum redundancy and maximum (mRMR) and the least absolute shrinkage and selection operator algorithm (LASSO), to select the features. Three radiomics models (DWI, FLAIR, and DWI-FLAIR) were established. A radiomics nomogram with patient characteristics and radiomics signature was built using a multivariate logistic regression model. The performance of the nomogram was evaluated in the test and validation sets. Ultimately, decision curve analysis was implemented to assess the clinical value of the nomogram. Results: The FLAIR, DWI, and DWI-FLAIR radiomics model exhibited good prediction performance, with area under the curve (AUCs) of 0.922 (95% CI: 0.876-0.968), 0.875 (95% CI: 0.815-0.935), and 0.895 (95% CI: 0.840-0.950). The radiomics nomogram with clinical characteristics including the overall cerebral small vessel disease (CSVD) burden score, hemorrhagic transformation (HT) and admission National Institutes of Health Stroke Scale score (NIHSS) score and the FLAIR Radscore presented good discriminatory potential in the training set (AUC = 0.94; 95% CI: 0.90-0.98) and test set (AUC = 0.94; 95% CI: 0.87-1), which was validated in the validation set 1 (AUC = 0.95; 95% CI: 0.88-1) and validation set 2 (AUC = 0.90; 95% CI: 0.768-1). In addition, it demonstrated good calibration, and decision curve analysis confirmed the clinical value of this nomogram. Conclusion: This non-invasive clinical-FLIAR radiomics nomogram shows good performance in predicting ischaemic stroke prognosis after thrombolysis.

The effect of MWA protocols upon morphology and IVIM parameters of hepatic ablation zones-a preliminary in vivo animal study with an MRI-compatible microwave ablation device.

PURPOSE We aimed to explore the effect of microwave ablation (MWA) protocols upon morphology and instant changes in intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters on MWA zones in porcine livers. METHODS According to the empirical protocol for MWA in tumors less than 3 cm in our hospital, the power and application duration were assigned as five groups: A, 60 W × 5 min (n = 6); B, 80 W × 3 min (n = 7); C, 80 W × 5 min (n = 10); D, 100 W × 3 min (n = 10); E, 100 W × 5 min (n = 9). Spearman correlation between MWA protocols, morphological metrics, and instant post-ablation IVIM parameters was performed. RESULTS There was fair positive correlation between energy delivery and short axis (RSpearman = 0.426, P= .005) of the white zone. There was moderate-to-good positive correlation between wattage and short axis (RSpearman = 0.584, P < .001) of the white zone. For post-ablation IVIM parameters in the white zone, only wattage had moderate-to-good positive correlation with D value (RSpearman= 0.574, P < .001) or ADC value (RSpearman = 0.550, P < .001). No correlation between energy delivery, wattage, duration, and f value was observed (RSpearman = 0.185, P = .24; RSpearman= - 0.001, P = .99; RSpearman = 0.203, P = .20, respectively). CONCLUSION The increase in the short axis of the white zone is more likely to be affected by wattage than energy delivery. The instant post-ablation IVIM is feasible in monitoring the MWA zones since the f value in the white zones is not sensitive to changes in MWA protocols, which is promising in evaluating the instant effect of MWA.

MARFit: An Integrated Software for Real-Time MR Guided Focused Ultrasound Neuromodulation System.

MR guided focused ultrasound (MRgFUS) therapy has been a promising treatment modality for many neurological disorders. However, the lack of real-time image processing software platform sets barriers for relevant pre-clinical researches. This work intends to develop an integrated software for MRgFUS therapy. The software contains three functional modules: a communication module, an image post-processing module, and a visualization module. The communication module provides a data interface with an open-source MR image reconstruction platform (Gadgetron) to receive the reconstructed MR images in real-time. The post-processing module contains the algorithms of image coordinate registration, focus localization by MR acoustic radiation force imaging (MR-ARFI), temperature and thermal dose calculations, motion correction, and temperature feedback control. The visualization module displays monitoring information and provides a user-machine interface. The software was tested to be compatible with systems from two different vendors and validated in multiple scenarios for MRgFUS. The software was tested in many ex vivo and in vivo experiments to validate its functions. The in vivo transcranial focus localization experiments were carried out for targeting the focused ultrasound in neuromodulation.

Reduced anterior cingulate glutamate of comorbid skin-picking disorder in adults with obsessive-compulsive disorder.

BACKGROUND: Obsessive Compulsive Disorder (OCD) is characterized by hyperactivity in a network of forebrain structures, including the anterior cingulate cortex (ACC). Convergent evidence suggests that glutamatergic dysfunction may contribute to the disorder. Skin picking disorder (SPD) was listed as one of the obsessive-compulsive and related disorders, which is often comorbid with OCD and share overlapping phenomenology and pathophysiology. However, potential confounding effects between the two diagnostic effects on neurotransmitter levels remain largely unexamined. METHODS: We examined the pregenual anterior cingulate cortex (pACC) glutamate and other neurochemicals in 62 subjects using a single-voxel acquisition 1H MRS at 3Tesla; of these, 47 subjects yielded usable measurements of both glutamate and glutamine and were included in the analysis (17 medicated with OCD alone, 13 medicated with comorbid OCD + SPD, 17 healthy control). RESULTS: OCD with comorbid SPD showed significantly lower pACC glutamate than in patients without SPD (p = 0.001) or control subjects (p = 0.035). OCD without SPD subjects showed pACC glutamate levels indistinguishable from controls (p = 0.501). In the OCD with SPD subjects, glutamate was correlated with Y-BOCS total score in female patients (n = 9, r = 0.69, p = 0.041). LIMITATIONS: The main limitation of the study was the cross-sectional data. Our patients were on SSRI medication which may have modified the effect of SPD and OCD interaction on glutamate activity. CONCLUSION: Our results suggest that alterations of the glutamatergic system may play an important role in the pathophysiology of a subgroup of OCD and reduced pACC glutamate may be a biomarker of a distinct subset of OCD patients.

Cortical hypoperfusion in patients with idiopathic rapid eye movement sleep behavior disorder detected with arterial spin-labeled perfusion MRI.

BACKGROUND: Idiopathic rapid eye movement sleep behavior disorder (iRBD) is an important risk factor for α-synucleinopathy. OBJECTIVE: We investigated alterations in the cerebral blood flow (CBF) based on arterial spin-labeled (ASL) imaging in patients with iRBD to determine brain perfusion changes associated with the disorder. METHODS: Fifteen patients with iRBD and twenty age-gender-matched healthy controls were enrolled. Cortical perfusions were compared between the two groups after the ASL data was co-registered to the high-resolution T1-weighted images. RESULTS: No significant differences were detected between the groups in regard to age, gender, education, or UPDRS-III score. The iRBD group showed a lower MMSE score than the healthy controls (27.07 ± 2.25 vs. 28.55 ± 1.23, p < 0.05). Compared with the healthy controls, the iRBD group showed significantly decreased CBF values in the right inferior frontal gyrus, right middle frontal gyrus, and right insula (p < 0.05 corrected). CONCLUSION: The cortical hypoperfusion areas in patients with iRBD were similar to the patterns in patients with α -synucleinopathies. ASL perfusion MRI is a potential approach to find biomarkers in preclinical stages of α -synucleinopathies.

Effects of levodopa therapy on voxel-based degree centrality in Parkinson's disease.

Levodopa therapy is widely recognized as an effective treatment for PD patients, however, it is rare of the study looking at effects of levodopa therapy on the whole-brain network. This study was to evaluate the effects of levodopa on whole-brain degree centrality (DC) and seed-based functional connectivity (FC) in PD patients. We recruited 26 PD patients and acquired their resting-state fMRI data before ('OFF' state) and after ('ON' state) taking a dose of 400 mg levodopa. Through constructing the voxel-based brain functional network, we calculated distant and local DC and seed-based FC. We found that compared to the healthy controls, the PD patients at 'OFF' state showed significantly decreased distant DC in several occipital regions and left postcentral gyrus, but increased distant DC in the right precentral gyrus, supplementary motor area, and several frontal regions. Meanwhile, we detected decreased local DC in the left cuneus and bilateral insula but increased local DC in several temporal regions in the PD patients at 'OFF' state compared to the controls. Using paired-sample t-tests, we found that levodopa effectively normalized the distant DC abnormalities in the PD patients particularly in the occipital regions and postcentral gyrus. Additionally, compared to 'OFF' state, the PD patients at 'ON' state showed decreased FC of the left median cingulate gyrus to brain regions in default mode network. The decreased FC of the left median cingulate gyrus to right temporal pole was associated with improved UPDRS-III score. This study provided new evidence for understanding the neural effects of levodopa therapy on the whole-brain network in PD patients.

Alterations of regional homogeneity in freezing of gait in Parkinson's disease.

INTRODUCTION: Freezing of gait (FOG) is a serious complication in patients with Parkinson's disease (PD), and is more common in the late state of the disease. The high risk of falling in patients with FOG impacts their quality of life. OBJECTIVE: To explore altered neuroactivity related to cognitive and executive function of PD patients with FOG. METHODS: Fourteen PD patients with FOG (FOG+), 20 PD patients without FOG (FOG-), and 18 normal controls (NC) were enrolled. Functional MRI data of all PD patients were collected during OFF medication state. Data were analyzed using software of DPARSF and REST. Resting brain activity was measured by regional homogeneity (ReHo). ANOVA test was performed for ReHo among FOG, PD, and NC groups. RESULTS: ReHo alterations of left supplementary motor area (SMA) (Brodmann 6), left superior frontal region (Brodmann 9), and the right putamen (Brodmann 48) were significantly different among the three groups. The ReHo values within left SMA (Brodmann 6) and left superior frontal region (Brodmann 9) were significantly decreased in FOG+ patients compared with FOG- patients. CONCLUSION: Changes in neural hypoactivity within the frontal region and SMA appear to be associated with FOG in PD patients, which suggests that the mechanism underlying FOG may relate to disruption of execution and cognition.

Analysis of petrous apex meningocele associated with meningioma: is there any relation with chronic intracranial hypertension?

PURPOSE: Petrous apex meningocele (PAM) is an uncommon cystic lesion involving the petrous apex. The underlying cause of PAM may be related to chronic elevated intracranial pressure. The aim of the study was to explore the relationship between PAM and meningioma and between PAM and other intracranial hypertension findings. METHODS: Two hundred seventy-eight consecutive patients with meningiomas were retrospectively studied. Fifty age- and gender-matched controls were also enrolled in this study. The incidence of PAM, empty sella, tortuosity of the optic nerve, and hydrops of optic nerve sheath was evaluated. The maximum width, area, volume of each PAM, or Meckel's cave and volume of meningioma were measured in controls and patients, separately. RESULTS: One hundred fifty-nine (57.19%) patients were detected with coexistent PAMs. One hundred twenty-five patients had bilateral PAMs, 34 had unilateral lesions, and the remaining 119 did not have PAM. Two subjects (4/50) had unilateral PAMs in normal controls. The maximum width, area, volume of PAM, or Meckel's cave were significantly larger in the patients with bilateral PAM group than those in the unilateral PAM group, in the group without PAM, and those in control group (p = 0.000). The volume of meningioma was positively correlated with the PAM volume (r = 0.48). There was a positive correlation for the incidence between PAM and (1) empty sella (r = 0.901) and (2) tortuosity of the optic nerves and hydrops of the optic sheath (r = 0.825). CONCLUSION: Coexistence of PAMs with meningiomas is not rare in incidence, and it suggests a potential role for chronically elevated intracranial pressure and disturbance of CSF circulation in their pathophysiology.

Altered modular organization of intrinsic brain functional networks in patients with Parkinson's disease.

Although previous studies reported altered topology of brain functional networks in patients with Parkinson's disease (PD), the modular organization of brain functional networks in PD patients remains largely unknown. Using the resting-state functional MRI (R-fMRI) and graph theory, we examined the modular organization of brain functional networks in 32 unmedicated patients with early-to-mid motor stage PD and 31 healthy controls. Compared to the controls, the PD patients tended to show decreased integrity and segregation, both within and between modules. This was inferred by significantly increased intra-modular characteristic path length (L p) within four modules: mPFC, SN, SMN, and FPN, decreased inter-modular functional connectivity (FC) between mPFC and SN, SMN, and VN, and decreased intra-modular clustering in the PD patients. Intra-modular characteristic path length within the mPFC showed significantly positive correlation with general cognitive ability in the PD group. Receiver operating characteristic (ROC) analysis revealed that FC between mPFC and SN had the highest significant accuracy in differentiating the patients from the controls. Our findings may provide new insight in understanding the pathological changes that underlie impairment in cognition and movement in Parkinson's disease.

Impaired topological architecture of brain structural networks in idiopathic Parkinson's disease: a DTI study.

Parkinson's disease (PD) is considered as a neurodegenerative disorder of the brain central nervous system. But, to date, few studies adopted the network model to reveal topological changes in brain structural networks in PD patients. Additionally, although the concept of rich club organization has been widely used to study brain networks in various brain disorders, there is no study to report the changed rich club organization of brain networks in PD patients. Thus, we collected diffusion tensor imaging (DTI) data from 35 PD patients and 26 healthy controls and adopted deterministic tractography to construct brain structural networks. During the network analysis, we calculated their topological properties, and built the rich club organization of brain structural networks for both subject groups. By comparing the between-group differences in topological properties and rich club organizations, we found that the connectivity strength of the feeder and local connections are lower in PD patients compared to those of the healthy controls. Furthermore, using a network-based statistic (NBS) approach, we identified uniformly significantly decreased connections in two modules, the limbic/paralimbic/subcortical module and the cognitive control/attention module, in patients compared to controls. In addition, for the topological properties of brain network topology in the PD patients, we found statistically increased shortest path length and decreased global efficiency. Statistical comparisons of nodal properties were also widespread in the frontal and parietal regions for the PD patients. These findings may provide useful information to better understand the abnormalities of brain structural networks in PD patients.

Altered Resting-State Functional Connectivity of the Striatum in Parkinson's Disease after Levodopa Administration.

BACKGROUND: Despite improvement in motor symptoms, the effect of dopaminergic medications on cognition in patients with Parkinson's disease (PD) is less clear. The purpose of this study was to reveal levodopa-induced acute changes in the functional connectivity of the striatum in patients with PD compared with matched untreated patients and healthy volunteers. METHODS: Twenty-two patients with PD underwent functional magnetic resonance imaging both ON and OFF dopamine-replacement therapy on two consecutive days. Twenty-eight normal aging volunteers also did them without taking in levodopa. Three caudate seeds and two putamen seeds were selected to calculate functional connectivity intensity. RESULTS: Motor symptoms measured by UPDRS were significantly worse in PD OFF than PD ON. Decreased functional connectivity in PD OFF compared to controls was detected in the following seed regions: dorsal caudate, ventral putamen and dorsal putamen. Increases in connectivity in PD ON compared to controls were found in the primary and supplementary motor areas and the associative prefrontal and parietal regions, while decreases in anterior cingulate, ventromedial prefrontal cortex, and parahippocampal gyrus. For the ventral striatal seeds, decreased connectivity in PD ON compared to PD OFF was found in the ventromedial prefrontal and orbitofrontal regions, dorsolateral prefrontal regions. For the dorsal striatal seeds, increased connectivity in PD ON compared to PD OFF was observed in the primary and secondary motor areas. CONCLUSION: Our results suggest that levodopa significantly changes the motor and cognitive networks of the cortico-striatal pathways. This knowledge will lead clinicians to survey a broader range of symptoms in determining optimal therapy.

The modulatory effect of semantic familiarity on the audiovisual integration of face-name pairs.

To recognize individuals, the brain often integrates audiovisual information from familiar or unfamiliar faces, voices, and auditory names. To date, the effects of the semantic familiarity of stimuli on audiovisual integration remain unknown. In this functional magnetic resonance imaging (fMRI) study, we used familiar/unfamiliar facial images, auditory names, and audiovisual face-name pairs as stimuli to determine the influence of semantic familiarity on audiovisual integration. First, we performed a general linear model analysis using fMRI data and found that audiovisual integration occurred for familiar congruent and unfamiliar face-name pairs but not for familiar incongruent pairs. Second, we decoded the familiarity categories of the stimuli (familiar vs. unfamiliar) from the fMRI data and calculated the reproducibility indices of the brain patterns that corresponded to familiar and unfamiliar stimuli. The decoding accuracy rate was significantly higher for familiar congruent versus unfamiliar face-name pairs (83.2%) than for familiar versus unfamiliar faces (63.9%) and for familiar versus unfamiliar names (60.4%). This increase in decoding accuracy was not observed for familiar incongruent versus unfamiliar pairs. Furthermore, compared with the brain patterns associated with facial images or auditory names, the reproducibility index was significantly improved for the brain patterns of familiar congruent face-name pairs but not those of familiar incongruent or unfamiliar pairs. Our results indicate the modulatory effect that semantic familiarity has on audiovisual integration. Specifically, neural representations were enhanced for familiar congruent face-name pairs compared with visual-only faces and auditory-only names, whereas this enhancement effect was not observed for familiar incongruent or unfamiliar pairs. Hum Brain Mapp 37:4333-4348, 2016. © 2016 Wiley Periodicals, Inc.

Delayed leukoencephalopathy of non-small cell lung cancer patients with brain metastases underwent whole brain radiation therapy.

To explore the incidence, MR imaging findings, dynamic developing process of delayed leukoencephalopathy (DLE) in non-small cell lung cancer (NSCLC) patients with brain metastases patients who undergone whole brain radiation (WBRT) therapy, we retrospectively reviewed 48 NSCLC patients who underwent WBRT for brain metastases from January 2010 through June 2015 and had evaluable magnetic resonance imaging after treatment. The DLE were graded using a scale to evaluate T2-FLAIR (fluid attenuated image recovery) images: grade 1 = little or no white matter hyperintensity, grade 2 = limited periventricular hyperintensity and grade 3 = diffuse white matter hyperintensity. 48 NSCLC patients with brain metastases were enrolled. The median age of these patients was 55.7 years (range 33-75 years). The median follow-up was 12 months. The characteristic MR imaging of DLE in those patients was bilaterally diffuse white matter T2 hyperintensity around the periventricular areas without enhancement, sparing from U-fiber, callosum and gray matter structure. The incidence of DLE developed 6.25% (3/48), 30.00% (12/40), 48.39% (15/31), 61.90% (13/21), 85.71% (6/7), 100% (3/3) in those patients who were followed up for 3, 6, 9, 12, 24, 36 months, respectively. Through increased understanding of it, it may be possible to help clinicians develop further therapeutic strategies to maximize benefit while limiting potential long term toxicities. These data supplement existing reports regarding the late effects of WBRT in NSCLC patients with brain metastasis.

Discriminative analysis of Parkinson's disease based on whole-brain functional connectivity.

Recently, there has been an increasing emphasis on applications of pattern recognition and neuroimaging techniques in the effective and accurate diagnosis of psychiatric or neurological disorders. In the present study, we investigated the whole-brain resting-state functional connectivity patterns of Parkinson's disease (PD), which are expected to provide additional information for the clinical diagnosis and treatment of this disease. First, we computed the functional connectivity between each pair of 116 regions of interest derived from a prior atlas. The most discriminative features based on Kendall tau correlation coefficient were then selected. A support vector machine classifier was employed to classify 21 PD patients with 26 demographically matched healthy controls. This method achieved a classification accuracy of 93.62% using leave-one-out cross-validation, with a sensitivity of 90.47% and a specificity of 96.15%. The majority of the most discriminative functional connections were located within or across the default mode, cingulo-opercular and frontal-parietal networks and the cerebellum. These disease-related resting-state network alterations might play important roles in the pathophysiology of this disease. Our results suggest that analyses of whole-brain resting-state functional connectivity patterns have the potential to improve the clinical diagnosis and treatment evaluation of PD.

The putaminal abnormalities on 3.0T magnetic resonance imaging: can they separate parkinsonism-predominant multiple system atrophy from Parkinson's disease?

BACKGROUND: The putaminal abnormalities detected on 1.5 T magnetic resonance imaging (MRI), such as putaminal atrophy, slit-like hyperintense rim, and hypointensity in the putamen on T2-weighted (T2W) imaging are important signs on differentiating multiple system atrophy with parkinsonism (MSA-P) from Parkinson's disease (PD). However, the putaminal abnormalities may have different manifestations on 3.0 T from those on 1.5 T. PURPOSE: To investigate the diagnostic value of putaminal abnormalities on 3.0 T MRI for differentiating MSA-P from PD. MATERIAL AND METHODS: The study included a MSA-P group (9 men, 9 women), a PD group (12 men, 14 women), and a control group (11 men, 13 women). All subjects were examined with 3.0 T MRI using the conventional protocol. Putaminal atrophy, T2-hypointensity in the dorsolateral putamenat, and a slit-like hyperintense rim on the lateral putamen were evaluated in each subject. RESULTS: There were no significant differences in the slit-like hyperintense rim (P = 0.782) or T2-hypointensity in the dorsolateral putamen (P = 0.338) among the three groups. Bilateral putaminal atrophy was found in 44.4% (8 of 18) of the MSA-P patients, in only 7.7% (2 of 26) of the PD patients, and in none of the controls. The proportion of subjects with putaminal atrophy was significantly higher in the MAS-P group (P = 0.008) and control group (P < 0.001). The specificity and sensitivity of putaminal atrophy for distinguishing MSA-P from PD was 92.3% and 44.4%, respectively. CONCLUSION: The signal changes in the putamen on T2W imaging on 3.0 T MRI, including slit-like hyperintense rim and putaminal hypointensity, are not specific signs for MSA-P. Putaminal atrophy is highly specific for differentiating MSA-P from PD and healthy controls, but its insufficient sensitivity limits its diagnostic value.

Reproducibility of high-resolution MRI for the middle cerebral artery plaque at 3T.

PURPOSE: To assess the reproducibility of HR-MRI for the identification of MCA atherosclerotic plaque components and quantification of stenosis. MATERIALS AND METHODS: Seventy-three consecutive subjects who initially had ischemic stroke or asymptomatic MCA stenosis (>50%) were enrolled in the study. All subjects were scanned using 3.0T MRI. Two independent readers reviewed all images and one reader reevaluated all images four weeks later. The tissue components of plaques were analyzed qualitatively and the vessels were quantitative measured. RESULTS: HR-MRI displayed the artery wall and lumen clearly. The intra-observer reproducibility was excellent for the identification of plaques (kappa [κ]=0.96; 95% CI: 0.83-1.04) and contrast enhancement (κ=0.89; 0.78-0.95); it was substantial for intra-plaque hemorrhage (κ=0.79; 0.57-0.96) and the fibrous cap (κ=0.65; 0.42-0.86). The inter-observer reproducibility was excellent for plaques (κ=0.92; 0.73-1.06), substantial for contrast enhancement (κ=0.80; 0.65-0.93), intra-plaque hemorrhage (κ=0.68; 0.47-0.92) and moderate for the fibrous cap (κ=0.58; 0.44-0.79). Both intra-observer and inter-observer reproducibility were excellent for quantitative vessel, lumen and wall measurements with intraclass correlation coefficients ranging from 0.91 to 0.97 and 0.87 to 0.96, respectively. However, vessel and wall areas and the intervals defined by the Bland-Altman plots were wide in comparison to the mean. CONCLUSIONS: The identification of MCA atherosclerotic plaque components and the quantification of vessel and lumen measurements are reproducible. The reproducibility is overall acceptable. HR-MRI may provide a useful tool for clinical risk evaluation in MCA atherosclerosis.