Combined texture analysis of dynamic contrast-enhanced MRI with histogram analysis of diffusion kurtosis imaging for predicting IDH mutational status in gliomas.

BACKGROUND: Non-invasive detection of isocitrate dehydrogenase (IDH) mutational status in gliomas is clinically meaningful for molecular stratification of glioma; however, it remains challenging. PURPOSE: To investigate the usefulness of texture analysis (TA) of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and histogram analysis of diffusion kurtosis imaging (DKI) maps for evaluating IDH mutational status in gliomas. MATERIAL AND METHODS: This retrospective study enrolled 84 patients with histologically confirmed gliomas, comprising IDH-mutant (n = 34) and IDH-wildtype (n = 50). TA was performed for the quantitative parameters derived by DCE-MRI. Histogram analysis was performed for the quantitative parameters derived by DKI. Unpaired Student's t-test was used to identify IDH-mutant and IDH-wildtype gliomas. Logistic regression and receiver operating characteristic (ROC) curve analyses were used to compare the diagnostic performance of each parameter and their combination for predicting the IDH mutational status in gliomas. RESULTS: Significant statistical differences in the TA of DCE-MRI and histogram analysis of DKI were observed between IDH-mutant and IDH-wildtype gliomas (all P < 0.05). Using multivariable logistic regression, the entropy of Ktrans, skewness of Ve, and Kapp-90th had higher prediction potential for IDH mutations with areas under the ROC curve (AUC) of 0.915, 0.735, and 0.830, respectively. A combination of these analyses for the identification of IDH mutation improved the AUC to 0.978, with a sensitivity and specificity of 94.1% and 96.0%, respectively, which was higher than the single analysis (P < 0.05). CONCLUSION: Integrating the TA of DCE-MRI and histogram analysis of DKI may help to predict the IDH mutational status.

Diffusion-relaxation correlation spectrum imaging for predicting tumor consistency and gross total resection in patients with pituitary adenomas: a preliminary study.

OBJECTIVE: To evaluate the ability of diffusion-relaxation correlation spectrum imaging (DR-CSI) to predict the consistency and extent of resection (EOR) of pituitary adenomas (PAs). METHODS: Forty-four patients with PAs were prospectively enrolled. Tumor consistency was evaluated at surgery as either soft or hard, followed by histological assessment. In vivo DR-CSI was performed and spectra were segmented following to a peak-based strategy into four compartments, designated A (low ADC), B (mediate ADC, short T2), C (mediate ADC, long T2), and D (high ADC). The corresponding volume fractions ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]) along with the ADC and T2 values were calculated and assessed using univariable analysis for discrimination between hard and soft PAs. Predictors of EOR > 95% were analyzed using logistic regression model and receiver-operating-characteristic analysis. RESULTS: Tumor consistency was classified as soft (n = 28) or hard (n = 16). Hard PAs presented higher [Formula: see text] (p = 0.001) and lower [Formula: see text] (p = 0.013) than soft PAs, while no significant difference was found in other parameters. [Formula: see text] significantly correlated with the level of collagen content (r = 0.448, p = 0.002). Knosp grade (odds ratio [OR], 0.299; 95% confidence interval [CI], 0.124-0.716; p = 0.007) and [Formula: see text] (OR, 0.834, per 1% increase; 95% CI, 0.731-0.951; p = 0.007) were independently associated with EOR > 95%. A prediction model based on these variables yielded an AUC of 0.934 (sensitivity, 90.9%; specificity, 90.9%), outperforming the Knosp grade alone (AUC, 0.785; p < 0.05). CONCLUSION: DR-CSI may serve as a promising tool to predict the consistency and EOR of PAs. CLINICAL RELEVANCE STATEMENT: DR-CSI provides an imaging dimension for characterizing tissue microstructure of PAs and may serve as a promising tool to predict the tumor consistency and extent of resection in patients with PAs. KEY POINTS: • DR-CSI provides an imaging dimension for characterizing tissue microstructure of PAs by visualizing the volume fraction and corresponding spatial distribution of four compartments ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]). • [Formula: see text] correlated with the level of collagen content and may be the best DR-CSI parameter for discrimination between hard and soft PAs. • The combination of Knosp grade and [Formula: see text] achieved an AUC of 0.934 for predicting the total or near-total resection, outperforming the Knosp grade alone (AUC, 0.785).

[Protective effects of luteolin preconditioning on rat liver under ischemia/reperfusion].

The aim of the study is to explore the effects of luteolin preconditioning on hepatic ischemia/reperfusion injury in rats and its mechanism, and investigate the effects of the change of heme oxygenase-1 (HO-1) activity on hepatic ischemia/reperfusion injury. Sprague-Dawley rats were divided into 5 groups randomly: control, model, luteolin, luteolin + zinc protoporphyrin (ZnPP, an inhibitor of HO-1) and hemin groups (n = 8 for each group). The rats in control, model and hemin groups received a standard chow daily. The rats in luteolin and luteolin + ZnPP groups received a chow supplemented with luteolin (200 mg/kg) daily. After 4 weeks, ZnPP (25 µmol/kg) and hemin (20 µmol/kg) were injected hypodermically 6 h before ischemia/reperfusion in luteolin + ZnPP and hemin groups, respectively. Portal vein and hepatic artery supplying the middle and left hepatic lobe were clamped with an atraumatic vascular clip for induction of partial hepatic ischemia in all rats except control group. After the 60 min of hepatic ischemia, a 60-minute reperfusion period was initiated by removal of the arterial clip. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were detected in serum, and the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in serum and liver were measured with assay kit. The expression of HO-1 protein and activity of HO-1 were examined in liver. The results showed that the luteolin and hemin pretreatment led to significant decreased levels of AST and ALT in serum, increased activity of SOD and decreased content of MDA in serum and liver compared with model group (P < 0.01). In addition, the expression of HO-1 protein and activity of HO-1 were elevated in luteolin and hemin groups (P < 0.01). ZnPP markedly increased the levels of AST and ALT in serum, and decreased the activities of SOD and HO-1, elevated MDA content in liver when compared with those in luteolin group (P < 0.01). Cytoplasmic vacuolation and swelling of hepatocytes were revealed in the model group after ischemia/reperfusion. Treatments with luteolin and hemin markedly relieved the liver structural changes. These results suggest that HO-1 protects rat liver from ischemia/reperfusion injury, and luteolin reduces the content of MDA and increases the activity of SOD and the expression of HO-1, which indicate that luteolin can elevate the antioxidation in rat liver, and thus protects rat liver from ischemia/reperfusion injury.