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Methylation of the O6-methylguanine methyltransferase (MGMT) gene promoter is correlated with the effectiveness of the current standard of care in glioblastoma patients. In this study, a deep learning pipeline is designed for automatic prediction of MGMT status in 87 glioblastoma patients with contrast-enhanced T1W images and 66 with fluid-attenuated inversion recovery(FLAIR) images. The end-to-end pipeline completes both tumor segmentation and status classification. The better tumor segmentation performance comes from FLAIR images (Dice score, 0.897 ± 0.007) compared to contrast-enhanced T1WI (Dice score, 0.828 ± 0.108), and the better status prediction is also from the FLAIR images (accuracy, 0.827 ± 0.056 ; recall, 0.852 ± 0.080 ; precision, 0.821 ± 0.022 ; and F 1 score, 0.836 ± 0.072). This proposed pipeline not only saves the time in tumor annotation and avoids interrater variability in glioma segmentation but also achieves good prediction of MGMT methylation status. It would help find molecular biomarkers from routine medical images and further facilitate treatment planning. [ABSTRACT FROM AUTHOR]

Purpose: To determine the diagnostic performance of intravoxel incoherent motion (IVIM) parameters to predict tumor recurrence after hepatectomy in patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).Materials and Methods: One hundred and fifty-seven patients (mean age 52.54 ± 11.32 years, 87% male) with surgically and pathologically confirmed HCC were included. Regions of interests were drawn including the tumors by two independent radiologists. ADC and IVIM-derived parameters (true diffusion coefficient [D]; pseudodiffusion coefficient [D*]; pseudodiffusion fraction [f]) were obtained preoperatively. The Cox proportional hazards model was used to analyze the predictors associated with tumor recurrence after hepatectomy.Results: Forty-seven of 157 (29.9%) patients experienced tumor recurrence. The multivariate Cox proportional hazards model revealed that a D value < 0.985 × 10-3 mm2/s (hazard ratio (HR), 0.190; p = 0.023) was a risk factor for tumor recurrence. Additional risk factors included younger age (HR, 0.328; p = 0.034) and higher serum alpha-fetoprotein (AFP) level (HR, 2.079; p = 0.013). Further, receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of the obtained Cox regression model improved from 0.68 for the combination of AFP and age alone to 0.724 for the combination of D value, AFP, and age.Conclusion: The D value derived from the IVIM model is a potential biomarker for the preoperative prediction of recurrence after hepatectomy in patients with HCC. When combined with age and AFP levels, D can improve the predictive performance for tumor recurrence.Key Points: • The recurrence rate of HCC after hepatectomy was higher in patients with ADC, D, and f values that were lower than the optimal cutoff values. • The optimal cutoff values of ADC, D, D*, and f for predicting recurrence in HBV associated HCC were 0.858 × 10-3 mm2/s, 0.985 × 10-3 mm2/s, 12.5 × 10-3 mm2/s, and 23.4%, respectively. • The D value derived from IVIM diffusion-weighted imaging may be a useful biomarker for preoperative prediction of recurrence after hepatectomy in patients with HCC. When combined with age and AFP levels, D can improve the predictive performance for tumor recurrence. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the value of intravoxel incoherent motion (IVIM) histogram analysis based on whole tumor volume in predicting microvascular invasion (MVI) of single hepatocellular carcinoma (HCC).Materials and Methods: The study enrolled 41 patients with pathologically proven HCCs who underwent IVIM diffusion-weighted imaging with nine b values and contrast-enhanced magnetic resonance imaging (MRI). Histogram parameters including mean; skewness; kurtosis; and percentiles (5th, 10th, 25th, 50th, 75th, 90th, 95th) were derived from apparent diffusion coefficient (ADC), perfusion fraction (f), true diffusion coefficient (D), and pseudo diffusion coefficient (D*). Quantitative histogram parameters and clinical data were compared between HCCs with and without MVI. For significant parameters, receiver operating characteristic (ROC) curves were further plotted to compare the diagnosis performance for identifying MVI.Results: The mean, 5th, 10th, 25th, 50th, and 75th percentiles of D, and the 5th, 10th, and 25th percentiles of ADC between HCCs with and without MVI were statistically significant (all P＜0.05). The histogram parameters of D* and f showed no statistically significant differences between HCCs with and without MVI (all P＞0.05). The areas under the ROC curves (AUCs) were 0.707-0.874 for D and 0.668-0.720 for ADC. The largest AUC of D (5th percentile) showed significantly higher accuracy than that of ADC or tumor size (P = 0.009-0.046). With a cut-off of 0.403 × 10-3 mm²/s, the 5th percentile of D value provided a sensitivity of 81% and a specificity of 85% in the prediction of MVI.Conclusions: Histogram analysis of IVIM based on whole tumor volume can be useful for predicting MVI. The 5th percentile of D was most useful value to predict MVI of HCC. [ABSTRACT FROM AUTHOR]

Background: Depression in the context of bipolar disorder (BD) is often misdiagnosed as unipolar depression (UD), leading to mistreatment and poor clinical outcomes. However, little is known about the similarities and differences in cerebellum between BD and UD.Methods: Patients with BD (n=35) and UD (n=30) during a depressive episode as well as 40 healthy controls underwent diffusional kurtosis imaging (DKI) and three dimensional arterial spin labeling (3D ASL). The DKI parameters including mean kurtosis (MK), axial kurtosis (Ka), radial kurtosis (Kr),fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (Da) and radial diffusivity (Dr) and 3D ASL parameters (i.e. cerebral blood flow) was measured by using regions-of-interest (ROIs) analysis in the superior cerebellar peduncles (SCP), middle cerebellar peduncles (MCP) and dentate nuclei (DN) of cerebellum.Results: Patients with UD exhibited significant differences from controls for DKI measures in bilateral SCP and MCP and cerebral blood flow (CBF) in bilateral SCP and left DN. Patients with BD exhibited significant differences from controls for DKI measures in the right MCP and left DN and CBF in the left DN. Patients with UD showed significantly lower MD values compared with patients with BD in the right SCP. Correlation analysis showed there were negative correlations between illness duration and MD and Dr values in the right SCP in UD.Limitations: This study was cross-sectional and the sample size was not large. Parts of the patients included were under medication prior to MRI scanning.Conclusions: Our findings provide new evidence of microstructural changes in cerebellum in BD and UD. The two disorders may have overlaps in microstructural abnormality in MCP and DN during the depressive period. Microstructural abnormality in SCP may be a key neurobiological feature of UD. [ABSTRACT FROM AUTHOR]

In Parkinson's disease (PD), iron elevation in specific brain regions as well as selective loss of dopaminergic neurons is a major pathologic feature. A reliable quantitative measure of iron deposition is a potential biomarker for PD and may contribute to the investigation of iron-mediated PD. The primary purpose of this study is to assess iron variations in multiple deep grey matter nuclei in early PD with a novel MRI technique, quantitative susceptibility mapping (QSM). The inter-group differences of susceptibility and R2* value in deep grey matter nuclei, namely head of caudate nucleus (CN), putamen (PUT), global pallidus (GP), substantia nigra (SN), and red nucleus (RN), and the correlations between regional iron deposition and the clinical features were explored in forty-four early PD patients and 35 gender and age-matched healthy controls. Susceptibility values were found to be elevated within bilateral SN and RN contralateral to the most affected limb in early PD compared with healthy controls (HCs). The finding of increased susceptibility in bilateral SN is consistent with work on a subgroup of patients at the earliest clinical detectable state (Hoehn and Yahr [1967]: Neurology 17:427-442; Stage I). However, increased R2* values were only seen within SN contralateral to the most affected limb in the PD group when compared with controls. Furthermore, bilateral SN magnetic susceptibility positively correlated with disease duration and UPDRS-III scores in early PD. This finding supports the potential value of QSM as a non-invasive quantitative biomarker of early PD. Hum Brain Mapp 36:4407-4420, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Gliomas grading is important for treatment plan; we aimed to investigate the application of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) in gliomas grading, by comparing with the three-dimensional pseudocontinuous arterial spin labeling (3D pCASL). 24 patients (13 high grade gliomas and 11 low grade gliomas) underwent IVIM DWI and 3D pCASL imaging before operation; maps of fast diffusion coefficient (D∗), slow diffusion coefficient (D), fractional perfusion-related volume (f), and apparent diffusion coefficient (ADC) as well as cerebral blood flow (CBF) were calculated and then coregistered to generate the corresponding parameter values. We found CBF and D∗ were higher in the high grade gliomas, whereas ADC, D, and f were lower (all P<0.05). In differentiating the high from low grade gliomas, the maximum areas under the curves (AUC) of D∗, CBF, and ADC were 0.857, 0.85, and 0.902, respectively. CBF was negatively correlated with f in tumor (r=-0.619, P=0.001). ADC was positively correlated with D in both tumor and white matter (r=0.887, P=0.000 and r=0.824, P=0.000, resp.). There was no correlation between CBF and D∗ in both tumor and white matter (P>0.05). IVIM DWI showed more efficiency than 3D pCASL but less validity than conventional DWI in differentiating the high from low grade gliomas. [ABSTRACT FROM AUTHOR]