PMC:2940017 / 4371-10637 JSONTXT

{"project":"TEST0","denotations":[{"id":"20495977-237-242-67271","span":{"begin":4207,"end":4208},"obj":"[\"11157178\"]"},{"id":"20495977-50-55-67272","span":{"begin":4651,"end":4652},"obj":"[\"10452715\"]"}],"text":"Materials and methods\nBetween 2004 and 2008, 49 consecutive patients with intra-axial brain tumours and tumour-like lesions were enrolled prospectively in our study. All patients included in our study had not received any kind of biopsy or treatment at the time of examination. Patients who were planned to undergo biopsy because of newly diagnosed intra-axial brain tumours received unenhanced brain CT in order to locate the lesion. The unenhanced CT was then used to plan the slice positions of PCT in order to hit the centre of the tumour. PCT was then followed by stereotactic or open biopsy in order to assess the histopathological grade of the examined tumour.\nAll radiological analyses were conducted in a blind fashion with regard to the patients’ identity, clinical data and initial diagnostic CT findings. The data were analysed by two experienced neuroradiologists (P.S., M.H.). Raters did not receive any information about the affected hemisphere. They evaluated unenhanced CT independently so as to designate the location and the margins of the tumour and to determine the sections that contained the largest part of solid tumour. In these sections, PCT analysis was carried out. Disputes between interpreters were decided by consensus.\nWritten informed consent was obtained from all participating patients. The study protocol was approved by the local Ethics and Scientific Committees of Heidelberg University School of Medicine.\n\nCT perfusion imaging\nAll PCTs were obtained with a standard 50-s PCT (Siemens Somatom Volume Zoom). The parameters for the PCT were 80 kV and 250 mAs, one image, slice collimation 2 × 10 mm. For the PCT, 33 patients received a biphasic protocol consisting of a total of 60 ml of a non-ionic contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany), injected using a high-pressure injector through an 18-gauge intravenous line in the cubital vein with a start delay of 4 s. The biphasic injection protocol consisted of 30 ml contrast material at a rate of 5 ml/s, immediately followed by another 30 ml at a rate of 2 ml/s and finally 20 ml of a saline chasing bolus at a rate of 2 ml/s. From every selected axial section 50 consecutive images were acquired with a time interval of 1 s.\nIn 16 patients, a different contrast protocol was applied. We utilised 36 ml of a non-ionic high concentrated iodine contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany) with an injection rate of 6 ml/s.\nIn order to verify that the different contrast protocols did not significantly influence the perfusion parameters, they were compared for the high-grade glioma patients, as high-grade gliomas represent the largest group in our series. Furthermore, all perfusion parameters in this histopathological subgroup were found to be significantly higher than normal parenchyma. The potential heterogeneity due to different contrast material protocols was assessed through the comparison of all perfusion parameters (Table 1). No significant difference was found between the two subgroups. Therefore they were evaluated as one entity for further statistical analysis.\nTable 1 Comparison of different contrast material protocols: Mann-Whitney U-test showed no significant difference between the two subgroups (values expressed as median and interquartile range)\nContrast material protocol 1 (n = 19) Contrast material protocol 2 (n = 10) p\nK trans (ml/100 ml/min) 5.80 4.04 \u003e0.05\n(4.43–9.45) (3.27–9.99)\nCBV (ml/100 ml) 5.37 5.58 \u003e0.05\n(4.36–6.74) (4.71–7.55)\nCBF (ml/min) 75.69 110.00 \u003e0.05\n(62.12–108.73) (84.99–132.18)\n\nData processing and analysis\nAll PCT images and parameters were analysed using a standard workstation (MMWP, Siemens, Erlangen, Germany) with commercially available software (Volume Perfusion CT, Siemens, Erlangen, Germany). Automatic segmentation was applied to exclude non-parenchymal pixels such as bone, cerebrospinal fluid (CSF) or vessels. In order to obtain peak vascular enhancement in blood, the superior sagittal sinus was selected as the venous reference vessel for the PCT process, as with 10-mm-thick axial sections a reliable absolute density evaluation of cerebral arteries can be restricted because of partial volume effects [1]. By applying the perfusion software, quantitative parameter images were generated from the time-attenuation curves. For each patient, four types of parameter maps were calculated for each section: temporal maximum intensity projection (MIP) in Hounsfield units (HU), CBV (ml/100 ml), CBF (ml/100 ml/min) and the volume transfer constant K Trans as a measure of permeability (ml/100 ml/min). CBF was calculated using the maximum slope model [9], CBV and K Trans were calculated using Patlak analysis (Appendix 1). The shape of the arterial input function necessary for the Patlak analysis was automatically determined from branches of the MCA or ACA, the peak of the input function was normalized to the peak of the superior sagittal sinus.\nThe raters then independently determined and manually drew regions of interest (ROIs) on the maps. Initially, ROIs were drawn on the MIP images, on the solid part of tumour, trying to exclude areas with necrosis or vessels. The ROIs were then automatically copied onto the perfusion maps and corresponding CBV, CBF and K Trans values were acquired. For every patient, reference ROIs were also drawn on the healthy contralateral hemisphere and perfusion parameters were obtained as control values.\n\nStatistical analysis\nThe results are presented as mean ± standard deviation (SD) and range for numerical variables and absolute numbers (percentage). Initially, the normal distribution of numerical variables through box plots, histograms and Q-Q plots was tested. The values of the parameters obtained from PCT analysis followed the Gaussian distribution except in a case of an oligodendral mixed glioma which was not included in the analysis. Wilcoxon paired sample test was used for the comparisons between tumour lesions and healthy parenchyma, because the data were used for the comparisons among the different histological subgroups. All p values reported are two-tailed. Statistical significance was set at 0.05 and analyses were conducted using SPSS statistical software version 12.0 (SPSS, Chicago, Ill., USA)."}

{"project":"0_colil","denotations":[{"id":"20495977-11157178-67271","span":{"begin":4207,"end":4208},"obj":"11157178"},{"id":"20495977-10452715-67272","span":{"begin":4651,"end":4652},"obj":"10452715"}],"text":"Materials and methods\nBetween 2004 and 2008, 49 consecutive patients with intra-axial brain tumours and tumour-like lesions were enrolled prospectively in our study. All patients included in our study had not received any kind of biopsy or treatment at the time of examination. Patients who were planned to undergo biopsy because of newly diagnosed intra-axial brain tumours received unenhanced brain CT in order to locate the lesion. The unenhanced CT was then used to plan the slice positions of PCT in order to hit the centre of the tumour. PCT was then followed by stereotactic or open biopsy in order to assess the histopathological grade of the examined tumour.\nAll radiological analyses were conducted in a blind fashion with regard to the patients’ identity, clinical data and initial diagnostic CT findings. The data were analysed by two experienced neuroradiologists (P.S., M.H.). Raters did not receive any information about the affected hemisphere. They evaluated unenhanced CT independently so as to designate the location and the margins of the tumour and to determine the sections that contained the largest part of solid tumour. In these sections, PCT analysis was carried out. Disputes between interpreters were decided by consensus.\nWritten informed consent was obtained from all participating patients. The study protocol was approved by the local Ethics and Scientific Committees of Heidelberg University School of Medicine.\n\nCT perfusion imaging\nAll PCTs were obtained with a standard 50-s PCT (Siemens Somatom Volume Zoom). The parameters for the PCT were 80 kV and 250 mAs, one image, slice collimation 2 × 10 mm. For the PCT, 33 patients received a biphasic protocol consisting of a total of 60 ml of a non-ionic contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany), injected using a high-pressure injector through an 18-gauge intravenous line in the cubital vein with a start delay of 4 s. The biphasic injection protocol consisted of 30 ml contrast material at a rate of 5 ml/s, immediately followed by another 30 ml at a rate of 2 ml/s and finally 20 ml of a saline chasing bolus at a rate of 2 ml/s. From every selected axial section 50 consecutive images were acquired with a time interval of 1 s.\nIn 16 patients, a different contrast protocol was applied. We utilised 36 ml of a non-ionic high concentrated iodine contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany) with an injection rate of 6 ml/s.\nIn order to verify that the different contrast protocols did not significantly influence the perfusion parameters, they were compared for the high-grade glioma patients, as high-grade gliomas represent the largest group in our series. Furthermore, all perfusion parameters in this histopathological subgroup were found to be significantly higher than normal parenchyma. The potential heterogeneity due to different contrast material protocols was assessed through the comparison of all perfusion parameters (Table 1). No significant difference was found between the two subgroups. Therefore they were evaluated as one entity for further statistical analysis.\nTable 1 Comparison of different contrast material protocols: Mann-Whitney U-test showed no significant difference between the two subgroups (values expressed as median and interquartile range)\nContrast material protocol 1 (n = 19) Contrast material protocol 2 (n = 10) p\nK trans (ml/100 ml/min) 5.80 4.04 \u003e0.05\n(4.43–9.45) (3.27–9.99)\nCBV (ml/100 ml) 5.37 5.58 \u003e0.05\n(4.36–6.74) (4.71–7.55)\nCBF (ml/min) 75.69 110.00 \u003e0.05\n(62.12–108.73) (84.99–132.18)\n\nData processing and analysis\nAll PCT images and parameters were analysed using a standard workstation (MMWP, Siemens, Erlangen, Germany) with commercially available software (Volume Perfusion CT, Siemens, Erlangen, Germany). Automatic segmentation was applied to exclude non-parenchymal pixels such as bone, cerebrospinal fluid (CSF) or vessels. In order to obtain peak vascular enhancement in blood, the superior sagittal sinus was selected as the venous reference vessel for the PCT process, as with 10-mm-thick axial sections a reliable absolute density evaluation of cerebral arteries can be restricted because of partial volume effects [1]. By applying the perfusion software, quantitative parameter images were generated from the time-attenuation curves. For each patient, four types of parameter maps were calculated for each section: temporal maximum intensity projection (MIP) in Hounsfield units (HU), CBV (ml/100 ml), CBF (ml/100 ml/min) and the volume transfer constant K Trans as a measure of permeability (ml/100 ml/min). CBF was calculated using the maximum slope model [9], CBV and K Trans were calculated using Patlak analysis (Appendix 1). The shape of the arterial input function necessary for the Patlak analysis was automatically determined from branches of the MCA or ACA, the peak of the input function was normalized to the peak of the superior sagittal sinus.\nThe raters then independently determined and manually drew regions of interest (ROIs) on the maps. Initially, ROIs were drawn on the MIP images, on the solid part of tumour, trying to exclude areas with necrosis or vessels. The ROIs were then automatically copied onto the perfusion maps and corresponding CBV, CBF and K Trans values were acquired. For every patient, reference ROIs were also drawn on the healthy contralateral hemisphere and perfusion parameters were obtained as control values.\n\nStatistical analysis\nThe results are presented as mean ± standard deviation (SD) and range for numerical variables and absolute numbers (percentage). Initially, the normal distribution of numerical variables through box plots, histograms and Q-Q plots was tested. The values of the parameters obtained from PCT analysis followed the Gaussian distribution except in a case of an oligodendral mixed glioma which was not included in the analysis. Wilcoxon paired sample test was used for the comparisons between tumour lesions and healthy parenchyma, because the data were used for the comparisons among the different histological subgroups. All p values reported are two-tailed. Statistical significance was set at 0.05 and analyses were conducted using SPSS statistical software version 12.0 (SPSS, Chicago, Ill., USA)."}

{"project":"2_test","denotations":[{"id":"20495977-11157178-29373456","span":{"begin":4207,"end":4208},"obj":"11157178"},{"id":"20495977-10452715-29373457","span":{"begin":4651,"end":4652},"obj":"10452715"}],"text":"Materials and methods\nBetween 2004 and 2008, 49 consecutive patients with intra-axial brain tumours and tumour-like lesions were enrolled prospectively in our study. All patients included in our study had not received any kind of biopsy or treatment at the time of examination. Patients who were planned to undergo biopsy because of newly diagnosed intra-axial brain tumours received unenhanced brain CT in order to locate the lesion. The unenhanced CT was then used to plan the slice positions of PCT in order to hit the centre of the tumour. PCT was then followed by stereotactic or open biopsy in order to assess the histopathological grade of the examined tumour.\nAll radiological analyses were conducted in a blind fashion with regard to the patients’ identity, clinical data and initial diagnostic CT findings. The data were analysed by two experienced neuroradiologists (P.S., M.H.). Raters did not receive any information about the affected hemisphere. They evaluated unenhanced CT independently so as to designate the location and the margins of the tumour and to determine the sections that contained the largest part of solid tumour. In these sections, PCT analysis was carried out. Disputes between interpreters were decided by consensus.\nWritten informed consent was obtained from all participating patients. The study protocol was approved by the local Ethics and Scientific Committees of Heidelberg University School of Medicine.\n\nCT perfusion imaging\nAll PCTs were obtained with a standard 50-s PCT (Siemens Somatom Volume Zoom). The parameters for the PCT were 80 kV and 250 mAs, one image, slice collimation 2 × 10 mm. For the PCT, 33 patients received a biphasic protocol consisting of a total of 60 ml of a non-ionic contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany), injected using a high-pressure injector through an 18-gauge intravenous line in the cubital vein with a start delay of 4 s. The biphasic injection protocol consisted of 30 ml contrast material at a rate of 5 ml/s, immediately followed by another 30 ml at a rate of 2 ml/s and finally 20 ml of a saline chasing bolus at a rate of 2 ml/s. From every selected axial section 50 consecutive images were acquired with a time interval of 1 s.\nIn 16 patients, a different contrast protocol was applied. We utilised 36 ml of a non-ionic high concentrated iodine contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany) with an injection rate of 6 ml/s.\nIn order to verify that the different contrast protocols did not significantly influence the perfusion parameters, they were compared for the high-grade glioma patients, as high-grade gliomas represent the largest group in our series. Furthermore, all perfusion parameters in this histopathological subgroup were found to be significantly higher than normal parenchyma. The potential heterogeneity due to different contrast material protocols was assessed through the comparison of all perfusion parameters (Table 1). No significant difference was found between the two subgroups. Therefore they were evaluated as one entity for further statistical analysis.\nTable 1 Comparison of different contrast material protocols: Mann-Whitney U-test showed no significant difference between the two subgroups (values expressed as median and interquartile range)\nContrast material protocol 1 (n = 19) Contrast material protocol 2 (n = 10) p\nK trans (ml/100 ml/min) 5.80 4.04 \u003e0.05\n(4.43–9.45) (3.27–9.99)\nCBV (ml/100 ml) 5.37 5.58 \u003e0.05\n(4.36–6.74) (4.71–7.55)\nCBF (ml/min) 75.69 110.00 \u003e0.05\n(62.12–108.73) (84.99–132.18)\n\nData processing and analysis\nAll PCT images and parameters were analysed using a standard workstation (MMWP, Siemens, Erlangen, Germany) with commercially available software (Volume Perfusion CT, Siemens, Erlangen, Germany). Automatic segmentation was applied to exclude non-parenchymal pixels such as bone, cerebrospinal fluid (CSF) or vessels. In order to obtain peak vascular enhancement in blood, the superior sagittal sinus was selected as the venous reference vessel for the PCT process, as with 10-mm-thick axial sections a reliable absolute density evaluation of cerebral arteries can be restricted because of partial volume effects [1]. By applying the perfusion software, quantitative parameter images were generated from the time-attenuation curves. For each patient, four types of parameter maps were calculated for each section: temporal maximum intensity projection (MIP) in Hounsfield units (HU), CBV (ml/100 ml), CBF (ml/100 ml/min) and the volume transfer constant K Trans as a measure of permeability (ml/100 ml/min). CBF was calculated using the maximum slope model [9], CBV and K Trans were calculated using Patlak analysis (Appendix 1). The shape of the arterial input function necessary for the Patlak analysis was automatically determined from branches of the MCA or ACA, the peak of the input function was normalized to the peak of the superior sagittal sinus.\nThe raters then independently determined and manually drew regions of interest (ROIs) on the maps. Initially, ROIs were drawn on the MIP images, on the solid part of tumour, trying to exclude areas with necrosis or vessels. The ROIs were then automatically copied onto the perfusion maps and corresponding CBV, CBF and K Trans values were acquired. For every patient, reference ROIs were also drawn on the healthy contralateral hemisphere and perfusion parameters were obtained as control values.\n\nStatistical analysis\nThe results are presented as mean ± standard deviation (SD) and range for numerical variables and absolute numbers (percentage). Initially, the normal distribution of numerical variables through box plots, histograms and Q-Q plots was tested. The values of the parameters obtained from PCT analysis followed the Gaussian distribution except in a case of an oligodendral mixed glioma which was not included in the analysis. Wilcoxon paired sample test was used for the comparisons between tumour lesions and healthy parenchyma, because the data were used for the comparisons among the different histological subgroups. All p values reported are two-tailed. Statistical significance was set at 0.05 and analyses were conducted using SPSS statistical software version 12.0 (SPSS, Chicago, Ill., USA)."}

{"project":"MyTest","denotations":[{"id":"20495977-11157178-29373456","span":{"begin":4207,"end":4208},"obj":"11157178"},{"id":"20495977-10452715-29373457","span":{"begin":4651,"end":4652},"obj":"10452715"}],"namespaces":[{"prefix":"_base","uri":"https://www.uniprot.org/uniprot/testbase"},{"prefix":"UniProtKB","uri":"https://www.uniprot.org/uniprot/"},{"prefix":"uniprot","uri":"https://www.uniprot.org/uniprotkb/"}],"text":"Materials and methods\nBetween 2004 and 2008, 49 consecutive patients with intra-axial brain tumours and tumour-like lesions were enrolled prospectively in our study. All patients included in our study had not received any kind of biopsy or treatment at the time of examination. Patients who were planned to undergo biopsy because of newly diagnosed intra-axial brain tumours received unenhanced brain CT in order to locate the lesion. The unenhanced CT was then used to plan the slice positions of PCT in order to hit the centre of the tumour. PCT was then followed by stereotactic or open biopsy in order to assess the histopathological grade of the examined tumour.\nAll radiological analyses were conducted in a blind fashion with regard to the patients’ identity, clinical data and initial diagnostic CT findings. The data were analysed by two experienced neuroradiologists (P.S., M.H.). Raters did not receive any information about the affected hemisphere. They evaluated unenhanced CT independently so as to designate the location and the margins of the tumour and to determine the sections that contained the largest part of solid tumour. In these sections, PCT analysis was carried out. Disputes between interpreters were decided by consensus.\nWritten informed consent was obtained from all participating patients. The study protocol was approved by the local Ethics and Scientific Committees of Heidelberg University School of Medicine.\n\nCT perfusion imaging\nAll PCTs were obtained with a standard 50-s PCT (Siemens Somatom Volume Zoom). The parameters for the PCT were 80 kV and 250 mAs, one image, slice collimation 2 × 10 mm. For the PCT, 33 patients received a biphasic protocol consisting of a total of 60 ml of a non-ionic contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany), injected using a high-pressure injector through an 18-gauge intravenous line in the cubital vein with a start delay of 4 s. The biphasic injection protocol consisted of 30 ml contrast material at a rate of 5 ml/s, immediately followed by another 30 ml at a rate of 2 ml/s and finally 20 ml of a saline chasing bolus at a rate of 2 ml/s. From every selected axial section 50 consecutive images were acquired with a time interval of 1 s.\nIn 16 patients, a different contrast protocol was applied. We utilised 36 ml of a non-ionic high concentrated iodine contrast agent (Imeron 400, Bracco Imaging, Konstanz, Germany) with an injection rate of 6 ml/s.\nIn order to verify that the different contrast protocols did not significantly influence the perfusion parameters, they were compared for the high-grade glioma patients, as high-grade gliomas represent the largest group in our series. Furthermore, all perfusion parameters in this histopathological subgroup were found to be significantly higher than normal parenchyma. The potential heterogeneity due to different contrast material protocols was assessed through the comparison of all perfusion parameters (Table 1). No significant difference was found between the two subgroups. Therefore they were evaluated as one entity for further statistical analysis.\nTable 1 Comparison of different contrast material protocols: Mann-Whitney U-test showed no significant difference between the two subgroups (values expressed as median and interquartile range)\nContrast material protocol 1 (n = 19) Contrast material protocol 2 (n = 10) p\nK trans (ml/100 ml/min) 5.80 4.04 \u003e0.05\n(4.43–9.45) (3.27–9.99)\nCBV (ml/100 ml) 5.37 5.58 \u003e0.05\n(4.36–6.74) (4.71–7.55)\nCBF (ml/min) 75.69 110.00 \u003e0.05\n(62.12–108.73) (84.99–132.18)\n\nData processing and analysis\nAll PCT images and parameters were analysed using a standard workstation (MMWP, Siemens, Erlangen, Germany) with commercially available software (Volume Perfusion CT, Siemens, Erlangen, Germany). Automatic segmentation was applied to exclude non-parenchymal pixels such as bone, cerebrospinal fluid (CSF) or vessels. In order to obtain peak vascular enhancement in blood, the superior sagittal sinus was selected as the venous reference vessel for the PCT process, as with 10-mm-thick axial sections a reliable absolute density evaluation of cerebral arteries can be restricted because of partial volume effects [1]. By applying the perfusion software, quantitative parameter images were generated from the time-attenuation curves. For each patient, four types of parameter maps were calculated for each section: temporal maximum intensity projection (MIP) in Hounsfield units (HU), CBV (ml/100 ml), CBF (ml/100 ml/min) and the volume transfer constant K Trans as a measure of permeability (ml/100 ml/min). CBF was calculated using the maximum slope model [9], CBV and K Trans were calculated using Patlak analysis (Appendix 1). The shape of the arterial input function necessary for the Patlak analysis was automatically determined from branches of the MCA or ACA, the peak of the input function was normalized to the peak of the superior sagittal sinus.\nThe raters then independently determined and manually drew regions of interest (ROIs) on the maps. Initially, ROIs were drawn on the MIP images, on the solid part of tumour, trying to exclude areas with necrosis or vessels. The ROIs were then automatically copied onto the perfusion maps and corresponding CBV, CBF and K Trans values were acquired. For every patient, reference ROIs were also drawn on the healthy contralateral hemisphere and perfusion parameters were obtained as control values.\n\nStatistical analysis\nThe results are presented as mean ± standard deviation (SD) and range for numerical variables and absolute numbers (percentage). Initially, the normal distribution of numerical variables through box plots, histograms and Q-Q plots was tested. The values of the parameters obtained from PCT analysis followed the Gaussian distribution except in a case of an oligodendral mixed glioma which was not included in the analysis. Wilcoxon paired sample test was used for the comparisons between tumour lesions and healthy parenchyma, because the data were used for the comparisons among the different histological subgroups. All p values reported are two-tailed. Statistical significance was set at 0.05 and analyses were conducted using SPSS statistical software version 12.0 (SPSS, Chicago, Ill., USA)."}