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It is always a great challenge to distinguish high-grade glioma (HGG) from primary central nervous system lymphoma (PCNSL). We conducted a meta-analysis to assess the performance of MR perfusion-weighted imaging (PWI) in differentiating HGG from PCNSL. The heterogeneity and threshold effect were evaluated, and the sensitivity (SEN), specificity (SPE) and areas under summary receiver operating characteristic curve (SROC) were calculated. Fourteen studies with a total of 598 participants were included in this meta-analysis. The results indicated that PWI had a high level of accuracy (area under the curve (AUC) = 0.9415) for differentiating HGG from PCNSL by using the best parameter from each study. The dynamic susceptibility-contrast (DSC) technique might be an optimal index for distinguishing HGGs from PCNSLs (AUC = 0.9812). Furthermore, the DSC had the best sensitivity 0.963 (95%CI: 0.924, 0.986), whereas the arterial spin-labeling (ASL) displayed the best specificity 0.896 (95% CI: 0.781, 0.963) among those techniques. However, the variability of the optimal thresholds from the included studies suggests that further evaluation and standardization are needed before the techniques can be extensively clinically used. [ABSTRACT FROM AUTHOR]

Objective: Magnetic resonance spectroscopy (MRS) is a powerful tool for preoperative grading of gliomas. We performed a meta-analysis to evaluate the diagnostic performance of MRS in differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs).Methods: PubMed and Embase databases were systematically searched for relevant studies of glioma grading assessed by MRS through 27 March 2015. Based on the data from eligible studies, pooled sensitivity, specificity, diagnostic odds ratio and areas under summary receiver operating characteristic curve (SROC) of different metabolite ratios were obtained.Results: Thirty articles comprising a total sample size of 1228 patients were included in our meta-analysis. Quantitative synthesis of studies showed that the pooled sensitivity/specificity of Cho/Cr, Cho/NAA and NAA/Cr ratios was 0.75/0.60, 0.80/0.76 and 0.71/0.70, respectively. The area under the curve (AUC) of the SROC was 0.83, 0.87 and 0.78, respectively.Conclusions: MRS demonstrated moderate diagnostic performance in distinguishing HGGs from LGGs using tumoural metabolite ratios including Cho/Cr, Cho/NAA and NAA/Cr. Although there was no significant difference in AUC between Cho/Cr and Cho/NAA groups, Cho/NAA ratio showed higher sensitivity and specificity than Cho/Cr ratio and NAA/Cr ratio. We suggest that MRS should combine other advanced imaging techniques to improve diagnostic accuracy in differentiating HGGs from LGGs.Key Points: • MRS has moderate diagnostic performance in distinguishing HGGs from LGGs. • There is no significant difference in AUC between Cho/Cr and Cho/NAA ratios. • Cho/NAA ratio is superior to NAA/Cr ratio. • Cho/NAA ratio shows higher sensitivity and specificity than Cho/Cr and NAA/Cr ratios. • MRS should combine other advanced imaging techniques to improve diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Objective To investigate the feasibility and reliability of virtual endoscopy (VE) as a rapid, low-cost, and interactive tool for the diagnosis and surgical planning of suprasellar arachnoid cysts (SACs). Methods Eighteen patients with SACs treated with endoscopic ventriculocystostomy were recruited, and 18 endoscopic patients treated with third ventriculostomy were randomly selected as a VE reconstruction control group. After loading their DICOM data into free 3D Slicer software, VE reconstruction was independently performed by 3 blinded clinicians and the time required for each reconstruction was recorded. Another 3 blinded senior neurosurgeons interactively graded the visibility of VE by watching video recordings of the endoscopic procedures. Based on the visibility scores, receiver operating characteristic curve analysis was used to investigate the reliability of VE to diagnose SACs, and Bland-Altman plots were used to assess the reliability of VE for surgical planning. In addition, the intraclass correlation coefficient was calculated to estimate the consistency among the results of 3 reconstruction performers. Results All 3 independent reconstructing performers successfully completed VE simulation for all cases, and the average reconstruction time was 10.2 ± 9.7 minutes. The area under the receiver operating characteristic curve of the cyst visibility score was 0.96, implying its diagnostic value for SACs. The Bland-Altman plot indicated good agreement between VE and intraoperative viewings, suggesting the anatomic accuracy of the VE for surgical planning. In addition, the intraclass correlation coefficient was 0.81, which revealed excellent interperformer consistency of our simulation method. Conclusions This study substantiated the feasibility and reliability of VE as a rapid, low-cost, and interactive modality for diagnosis and surgical planning of SACs. [ABSTRACT FROM AUTHOR]