Meningioma is a common intracranial neoplasm derived from meningothelial cells. Meningiomas are associated with a benign clinical course. However, malignant behaviour such as metastatic disease has been also described. Our aim was to analyze the metastatic pattern taking tumor grading into consideration, and to determine clinical signs of distant metastases in meningiomas. In this systematic review PubMed database was screened for distant meningioma metastases from 1990 to 2012. 95 articles were identified. Only cases with metastasized meningiomas were included in the analysis. Our analysis comprised 115 cases with 164 metastatic lesions. Primary tumors were in 33.9 % grade 1, 20.9 % grade 2, and 40 % grade 3. In 5.2 % the grade was not reported. In 93 % meningiomas were diagnosed and resected before distant metastases occurred. In 6.1 % metastases were identified simultaneously with primary tumors and in 0.9 % metastases were identified before the primary tumor was found. The metastatic lesions were localized most frequently in the lung (37.2 %), bones (16.5 %), intraspinally (15.2 %), and in the liver (9.2 %). Other locations were rarer. The size of the metastases varied from 0.6 to 28 cm (median size, 3 cm). There were no significant differences between sizes of the identified metastases in relation to tumor grading. 50.4 % of distant metastases were clinically manifest and 31.3 % were identified incidentally. In 18.3 % clinical signs were missing. In our review 31.3 % of metastatic meningiomas were found to be clinically silent. The prevalence of metastases in meningioma may be underreported.
OBJECTIVES: To analyze diffusion-weighted imaging (DWI) findings of meningiomas and to compare them with tumor grade, cell count, and proliferation index and to test a possibility of use of apparent diffusion coefficient (ADC) to differentiate benign from atypical/malignant tumors. METHODS: Forty-nine meningiomas were analyzed. DWI was done using a multislice single-shot echo-planar imaging sequence. A polygonal region of interest was drawn on ADC maps around the margin of the lesion. In all lesions, minimal ADC values (ADCmin) and mean ADC values (ADCmean) were estimated. Normalized ADC (NADC) was calculated in every case as a ratio ADCmean meningioma/ADCmean white matter. All meningiomas were surgically resected and analyzed histopathologically. The tumor proliferation index was estimated on Ki-67 antigen–stained specimens. Cell density was calculated. Collected data were evaluated by means of descriptive statistics. Analyses of ADC/NADC values were performed by means of two-sided t tests. RESULTS: The mean ADCmean value was higher in grade I meningiomas in comparison to grade II/III tumors (0.96 vs 0.80 × 10− 3 mm2s− 1, P = .006). Grade II/III meningiomas showed lower NADC values in comparison to grade I tumors (1.05 vs 1.26, P = .015). There was no significant difference in ADCmin values between grade I and II/III tumors (0.69 vs 0.63 × 10− 3 mm2s− 1, P = .539). The estimated cell count varied from 486 to 2091 (mean value, 1158.20 ± 333.74; median value, 1108). There were no significant differences in cell count between grade I and grade II/III tumors (1163.93 vs 1123.86 cells, P = .77). The mean level of the proliferation index was 4.78 ± 5.08%, the range was 1% to 18%, and the median value was 2%. The proliferation index was statistically significant higher in grade II/III meningiomas in comparison to grade I tumors (15.43% vs 3.00%, P = .001). Ki-67 was negatively associated with ADCmean (r = − 0.61, P < .001) and NADC (r = − 0.60, P < .001). No significant correlations between cell count and ADCmean (r = − 0.20, P = .164) or NADC (r = − 0.25, P = .079) were found.ADCmin correlated statistically significant with cell count (r = − 0.44, P = .002) but not with Ki-67 (r = − 0.22, P = .129). Furthermore, the association between ADCmin and cell count was stronger in grade II/III tumors (r = − 0.79, P = .036) versus grade I meningiomas (r = − 0.41, P = .008). An ADCmean value of less than 0.85 × 10− 3 mm2s− 1 was determined as the threshold in differentiating between grade I and grade II/III meningiomas (sensitivity 72.9%, specificity 73.1%, accuracy 73.0%). The positive and negative predictive values were 33.3% and 96.8%, respectively. The same threshold ADCmean value was used in differentiating between tumors with Ki-67 level ≥ 5% and meningiomas with low proliferation index (Ki-67 < 5%). This threshold yielded a sensitivity of 70.6%, a specificity of 81.2%, and an accuracy of 77.6%. The positive and negative predictive values were 66.6% and 83.9%, respectively. CONCLUSIONS: Grade II/III tumors had lower ADCme...
Background: Significant coronary artery disease (CAD) is a common finding in patients undergoing transcatheter aortic valve implantation (TAVI). Assessment of CAD prior to TAVI is recommended by current guidelines and is mainly performed via invasive coronary angiography (ICA). In this study we analyzed the ability of coronary CT-angiography (cCTA) to rule out significant CAD (stenosis ≥ 50%) during routine pre-TAVI evaluation in patients with high pre-test probability for CAD. Methods: In total, 460 consecutive patients undergoing pre-TAVI CT (mean age 79.6 ± 7.4 years) were included. All patients were examined with a retrospectively ECG-gated CT-scan of the heart, followed by a high-pitch-scan of the vascular access route utilizing a single intravenous bolus of 70 mL iodinated contrast medium. Images were evaluated for image quality, calcifications, and significant CAD; CT-examinations in which CAD could not be ruled out were defined as positive (CAD+). Routinely, patients received ICA (388/460; 84.3%; Group A), which was omitted if renal function was impaired and CAD was ruled out on cCTA (Group B). Following TAVI, clinical events were documented during the hospital stay. Results: cCTA was negative for CAD in 40.2% (188/460). Sensitivity, specificity, PPV, and NPV in Group A were 97.8%, 45.2%, 49.6%, and 97.4%, respectively. Median coronary artery calcium score (CAC) was higher in CAD+-patients but did not have predictive value for correct classification of patients with cCTA. There were no significant differences in clinical events between Group A and B. Conclusion: cCTA can be incorporated into pre-TAVI CT-evaluation with no need for additional contrast medium. cCTA may exclude significant CAD in a relatively high percentage of these high-risk patients. Thereby, cCTA may have the potential to reduce the need for ICA and total amount of contrast medium applied, possibly making pre-procedural evaluation for TAVI safer and faster.
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