Jianping Dai

Clival invasion on multi-detector CT in 390 pituitary macroadenomas: correlation with sex, subtype and rates of operative complication and recurrence.

BACKGROUND AND PURPOSE: Clival invasion, a rare but potentially significant complication of pituitary adenoma, is difficult to detect on MR imaging. Because CT is widely used in adjunct guidance of pituitary surgery and it has recently been suggested that preoperative CT may add useful diagnostic information in addition to pituitary MR imaging, we performed the first large cross-sectional imaging study to define the image attributes, clinical correlates, and prognostic implications of clival invasion on CT for pituitary adenoma surgical guidance. MATERIALS AND METHODS: Preoperative CT images from 390 patients with histopathologically diagnosed pituitary macroadenoma were reviewed retrospectively and classified by the presence and degree of clival invasion. Tumor volume, tumor subtype, patient sex, operative complication, and recurrence rates were compared between groups. RESULTS: After we corrected for multiple correlations, the most significant independent risk factor for clival invasion was female sex (OR = 3.62, P = .014, multinomial logistic regression), followed by large tumor volume (OR = 1.08, P < .001), and null-cell subtype (OR = 5.47, P < .001). Larger tumor volume correlated with null-cell subtype (Mann-Whitney U test, P = .006), incidence of clival invasion (P < .001), and extent of clival invasion (P = .038). Clival invasion was associated with a significantly higher ratio of operative complications (15.63%, χ2 = 7.067, P = .008) and recurrence (57.14%, χ2 = 10.739, P = .001). CONCLUSIONS: CT detection of clival invasion by pituitary macroadenoma is significantly more common in women, in patients with large tumors, and in patients with null-cell tumors, and it is associated with a higher rate of operative complications and recurrences. Attention to the presence of clival invasion on preoperative CT and prospective investigation of its prognostic significance are indicated. Attention to this finding on pituitary guidance CT is warranted.

Differentiation between Brain Glioblastoma Multiforme and Solitary Metastasis: Qualitative and Quantitative Analysis Based on Routine MR Imaging

This article addresses a common clinical dilemma: is a solitary lesion a GBM or a metastasis? The authors here studied, qualitatively and quantitatively, findings on routine MR brain imaging. They simply measured the T2 signal intensity of the peritumoral edema in both lesions and normalized it to the contralateral corresponding area. GBMs had a higher normalized edema signal intensity when compared with metastases. Thus, this simple method may aid in distinguishing between these 2 lesions. BACKGROUND AND PURPOSE: The differentiation between cerebral GBM and solitary MET is clinically important and may be radiologically challenging. Our hypothesis is that routine MR imaging with qualitative and quantitative analysis is helpful for this differentiation. MATERIALS AND METHODS: Forty-five GBM and 21 solitary metastases were retrospectively identified, with their preoperative routine MR imaging analyzed. According to the comparison of the area of peritumoral T2 prolongation with that of the lesion, the tumors were classified into grade I (prolongation area ≤ tumor area) and grade II (prolongation area > tumor area). The signal intensities of peritumoral T2 prolongation were measured on T2WI and normalized to the values of the contralateral normal regions by calculating the ratios. The ratio (nSI) of both types of tumors was compared in grade I, grade II, and in tumors without grading. The best cutoff values to optimize the sensitivity and specificity were determined for optimal differentiation. RESULTS: The nSI of GBM was significantly higher than that of MET without T2 prolongation grading (P < .001), resulting in AUC = 0.725. The difference was significant (P = .014) in grade I tumors (GBM, 38; MET, 9), with AUC = 0.741, and in grade II tumors (GBM, 7; MET, 12), with AUC = 0.869 (P = .017). Both types of tumors showed a different propensity in T2 prolongation grading (χ2 = 12.079, P = .001). CONCLUSIONS: Combined with qualitative and quantitative analysis of peritumoral T2 prolongation, routine MR imaging can help in the differentiation between brain GBM and solitary MET.

Dysfunction of Affective Network in Post Ischemic Stroke Depression: A Resting-State Functional Magnetic Resonance Imaging Study

Objective. Previous studies have demonstrated that stroke characteristics and social and psychological factors jointly contribute to the development of poststroke depression (PSD). The purpose of this study was to identify altered functional connectivity (FC) of the affective network (AN) in patients with PSD and to explore the correlation between FC and the severity of PSD. Materials and Methods. 26 PSD patients, 24 stroke patients without depression, and 24 age-matched normal controls underwent the resting-state functional MRI (fMRI) scanning. The bilateral anterior cingulated cortices (ACCs) were selected as regions of interest (ROIs). FC was calculated and compared among the three groups. The association between FC and Hamilton Depression Rate Scale (HDRS) scores of PSD group was investigated. Results. The FC of the AN was disrupted in PSD patients compared to stroke patients without depression and normal controls. Moreover, the left orbital part of inferior frontal gyrus which indicated altered FC was significantly correlated with HDRS scores in PSD patients. Conclusions. Dysfunction of the affective network may be one of the reasons of the development of PSD.

Intracranial Meningeal Hemangiopericytomas in Children and Adolescents: CT and MR Imaging Findings

SUMMARY: Intracranial meningeal hemangiopericytomas in children and adolescents are prone to bleeding during surgery. CT and MR imaging may serve a role in preoperative diagnosis. The purpose of this report was to describe the radiologic findings in 9 pathologically proved cases of intracranial meningeal hemangiopericytomas in children and adolescents. The average duration of symptoms was short (mean, 4.0 months; median, 1.5 months). The intraoperative blood loss was large (mean, 3561 mL; median, 1000 mL). Tumors were extra-axial, irregularly multilobular, and hypervascular. Radiologically, they showed mixed attenuation on precontrast CT images, heterogeneous signal intensity on precontrast MR imaging, and marked and heterogeneous enhancement on postcontrast MR imaging. Bone erosion was sometimes present, but hyperostosis was not present. On MR imaging, multiple signal intensity voids of vessels were observed in 100% (8/8) of tumors with AVM-like signal intensity flow voids in 25% (2/8) of tumors. These results suggest that CT and MR imaging findings may be helpful for preoperative diagnosis.

Residual low ADC and high FA at the resection margin correlate with poor chemoradiation response and overall survival in high-grade glioma patients

PURPOSE We hypothesized that ADC and FA of enhancing tumor (ET) and/or non-enhancing tumor (NT) adjacent to the operative resection margin before and during temozolomide and/or chemoradiation may allow prediction of chemoradiation response and patient survival. MATERIAL AND METHODS DTI was acquired in 37 patients with newly diagnosed HGG at two time points: after resection at the time of pre-RT planning MRI (Baseline) and after 30Gy of radiation therapy (mid-RT). ADC and FA at each time point and change in ADC and FA between the two time points were assessed by hot spot method in both residual ET and NT within 2cm of the resection margin and correlated with overall survival (OS) using receiver operating characteristics (ROC) area under curve (AUC) analysis and log-rank testing. RESULTS At baseline NT ADC<104×10(-5)mm(2)/s was strongly correlated with shorter 15 month OS (95% CI: 227-412 days vs 492-695 days) compared to patients with higher ADC (AUC 0.82). There was good separation between the groups and significance at log-rank testing (p=0.0002). Baseline NT FA>0.257 also correlated with shorter OS (95% CI: 300-515 days vs 438-686 days), compared with patients with lower FA (AUC 0.74), but there was considerable overlap between the groups and non-significance at log-rank testing (p=0.089). Residual ET ADC increased significantly (p=0.0004) and FA decreased significantly (p=0.03) for all patients during early RT but the change in ADC and FA was less strongly correlated with OS than baseline NT metrics. CONCLUSION Post-operative pre-radiation baseline low ADC in non-enhancing tumor at the resection margin correlates strongly with worse treatment response and decreased overall survival in a heterogeneous sample of high grade glioma patients treated with radiation and/or temozolamide chemoradiation.

Meningiomas of the cerebellopontine angle: radiological differences in tumors with internal auditory canal involvement and their influence on surgical outcome.

This study explored the clinical, radiological, and pathological characteristics of cerebellopontine angle (CPA) meningiomas with internal auditory canal (IAC) involvement. The pre- and postoperative MR images of 193 consecutive patients with pathologically diagnosed meningioma centered around the IAC were analyzed, focusing on changes in the IAC, maximal axial tumor volume, peritumoral brain edema, and postoperative residual tumor. Patient age, sex, tumor volume, postoperative residual tumor, and pathological subtype were compared in patients with and without IAC involvement by the tumor and among the different types of IAC involvement. The results showed that the 71 patients (36.8%) with IAC involvement had a higher ratio of peritumoral edema (χ2=5.922, P=0.015), postoperative residual tumor (χ2=22.183, P< 0.001), and a predominance of the meningothelial subtype (χ2=5.89, P=0 .015). Peritumoral edema was a risk factor for IAC involvement (P=0.016, OR=2.186). Radiologically, IAC involvement could be distinguished as intruding (31%, 22/71), filled (29.6%, 21/71), and dilated (39.4%, 28/71). Patients with intruding IAC were significantly older (54.5±9.54 years, P=0.021) and had the lowest postoperative residual tumor values (42%, χ2=7.865, P= 0.005), while those with filled IAC were more likely to be female (95%, χ2=9.404, P=0.009).Our observations provide the basis for a morphological classification of IAC involvement by CPA meningiomas and further insight into the clinical features of these tumors.

Convex-Envelope Based Automated Quantitative Approach to Multi-Voxel 1H-MRS Applied to Brain Tumor Analysis.

Background Magnetic Resonance Spectroscopy (MRS) can measure in vivo brain tissue metabolism that exhibits unique biochemical characteristics in brain tumors. For clinical application, an efficient and versatile quantification method of MRS would be an important tool for medical research, particularly for exploring the scientific problem of tumor monitoring. The objective of our study is to propose an automated MRS quantitative approach and assess the feasibility of this approach for glioma grading, prognosis and boundary detection. Methods An automated quantitative approach based on a convex envelope (AQoCE) is proposed in this paper, including preprocessing, convex-envelope based baseline fitting, bias correction, sectional baseline removal, and peak detection, in a total of 5 steps. Some metabolic ratios acquired by this quantification are selected for statistical analysis. An independent sample t-test and the Kruskal-Wallis test are used for distinguishing low-grade gliomas (LGG) and high-grade gliomas (HGG) and for detecting the tumor, peritumoral and contralateral areas, respectively. Seventy-eight cases of pre-operative brain gliomas with pathological reports are included in this study. Results Cho/NAA, Cho/Cr and Lip-Lac/Cr (LL/Cr) calculated by AQoCE in the tumor area differ significantly between LGG and HGG, with p≤0.005. Using logistic regression combining Cho/NAA, Cho/Cr and LL/Cr to generate a ROC curve, AQoCE achieves a sensitivity of 92.9%, a specificity of 72.2%, and an area under ROC curve (AUC) of 0.860. Moreover, both Cho/NAA and Cho/Cr in the AQoCE approach show a significant difference (p≤0.019) between tumoral, peritumoral, and contralateral areas. The comparison between the results of AQoCE and Siemens MRS processing software are also discussed in this paper. Conclusions The AQoCE approach is an automated method of residual water removal and metabolite quantification. It can be applied to multi-voxel 1H-MRS for evaluating brain glioma grading and demonstrating characteristics of brain glioma metabolism. It can also detect infiltration in the peritumoral area. Under the limited clinical data used, AQoCE is significantly more versatile and efficient compared to the reference approach of Siemens.

Patterns of Tumor Contrast Enhancement Predict the Prognosis of Anaplastic Gliomas with IDH1 Mutation

BACKGROUND AND PURPOSE: It is proposed that isocitrate dehydrogenase 1 (IDH1) mutation predicts the outcome in patients with high-grade glioma. In addition, contrast enhancement on preoperative MR imaging reflects tumor biologic features. Patients with anaplastic glioma with the IDH1 mutation were evaluated by using MR imaging to determine whether tumor enhancement is a prognostic factor and can be used to predict survival. MATERIALS AND METHODS: A cohort of 216 patients with histologically confirmed anaplastic glioma was reviewed retrospectively. Tumor contrast-enhancement patterns were classified on the basis of preoperative T1 contrast MR images. Tumor IDH1 status was examined by using RNA sequencing. We used univariate analysis and the multivariate Cox model to evaluate the prognostic value of the IDH1 mutation and tumor contrast-enhancement pattern for progression-free survival and overall survival. RESULTS: In all 216 patients, IDH1 mutation was associated with longer progression-free survival (P = .004, hazard ratio = 0.439) and overall survival (P = .002, hazard ratio = 0.406). For patients with IDH1 mutant anaplastic glioma, the absence of contrast enhancement was associated with longer progression-free survival (P = .038, hazard ratio = 0.473) and overall survival (P = .043, hazard ratio = 0.436). Furthermore, we were able to stratify the progression-free survival and overall survival of patients with IDH1 mutation by using the tumor contrast-enhancement patterns (P = .022 and 0.029, respectively; log-rank). CONCLUSIONS: Tumor enhancement on postcontrast MR imaging is a valuable prognostic factor for patients with anaplastic glioma and IDH1 mutation. Furthermore, the contrast-enhancement patterns could potentially be used to stratify the survival outcome of such patients.

Identifying the association between contrast enhancement pattern, surgical resection, and prognosis in anaplastic glioma patients

IntroductionContrast enhancement observable on magnetic resonance (MR) images reflects the destructive features of malignant gliomas. This study aimed to investigate the relationship between radiologic patterns of tumor enhancement, extent of resection, and prognosis in patients with anaplastic gliomas (AGs).MethodsClinical data from 268 patients with histologically confirmed AGs were retrospectively analyzed. Contrast enhancement patterns were classified based on preoperative T1-contrast MR images. Univariate and multivariate analyses were performed to evaluate the prognostic value of MR enhancement patterns on progression-free survival (PFS) and overall survival (OS).ResultsThe pattern of tumor contrast enhancement was associated with the extent of surgical resection in AGs. A gross total resection was more likely to be achieved for AGs with focal enhancement than those with diffuse (p = 0.001) or ring-like (p = 0.024) enhancement. Additionally, patients with focal-enhanced AGs had a significantly longer PFS and OS than those with diffuse (log-rank, p = 0.025 and p = 0.031, respectively) or ring-like (log-rank, p = 0.008 and p = 0.011, respectively) enhanced AGs. Furthermore, multivariate analysis identified the pattern of tumor enhancement as a significant predictor of PFS (p = 0.016, hazard ratio [HR] = 1.485) and OS (p = 0.030, HR = 1.446).ConclusionOur results suggested that the contrast enhancement pattern on preoperative MR images was associated with the extent of resection and predictive of survival outcomes in AG patients.

Radiologic Features and Expression of Vascular Endothelial Growth Factor Stratify Survival Outcomes in Patients with Glioblastoma

BACKGROUND AND PURPOSE: Vascular endothelial growth factor is a well-known tumor-specific biomarker that mediates angiogenesis in glioblastoma via hypoxia-dependent mechanisms. Our aim was to investigate the correlation of clinical characteristics, radiologic features, and vascular endothelial growth factor expression with survival outcomes in patients with glioblastoma. MATERIALS AND METHODS: Clinical and radiologic data of 185 patients with glioblastoma were retrospectively reviewed. Vascular endothelial growth factor expression was examined in all cases via immunohistochemical analysis. Univariate and multivariate analyses were performed to identify the prognostic factors of progression-free survival and overall survival. RESULTS: Vascular endothelial growth factor expression levels were associated with the presence of ringlike tumor contrast enhancement. Age, preoperative Karnofsky Performance Scale score, gross total resection, and adjuvant therapy were identified as prognostic factors. Among patients undergoing gross total resection, high vascular endothelial growth factor expression was associated with longer progression-free survival (P = .011) and overall survival (P = .039). For tumors with high vascular endothelial growth factor expression, both the non-contrast-enhancing tumor component and peritumoral edema could stratify overall survival (P = .039 and .018, respectively), while only the presence of the non-contrast-enhancing tumor component predicted a longer progression-free survival (P = .024). CONCLUSIONS: Vascular endothelial growth factor expression level was not an independent prognostic factor in glioblastoma. However, high vascular endothelial growth factor expression might predict longer survival in patients in whom gross total resection was achieved. Furthermore, peritumoral edema and the non-contrast-enhancing tumor component could stratify survival outcomes in patients with high vascular endothelial growth factor tumors.