XII.
European Stroke Conference Valencia, Spain
21 - 24 May 2003
XII.
European Stroke Conference
Valencia, Spain
21 - 24 May 2003
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Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.20-9.30
Room: Auditorium II
Diffusion-weighted MR-imaging during the early phase of global cerebral hypoxia: a predictor for clinical outcome?
T. Els
J. Klisch
R. Kubalek
J. Kassubek
M. Herpers
C.H.Lucking
GERMANY
University of Freiburg
Background and purpose: Due to the improvement of intensive care medicine, an increasing number of patients develop an acute vegetative state following global cerebral hypoxia in cardiac arrest - the estimated number for Germany might be 3000/a. Prognostic assessment in clinical routine is often difficult. Diffusion-weighted imaging (DWI) is sensitive for ischemia dependent watershifts between the extra- and intracellular compartments. With respect to some limitations DWI is the method of choice to deline severe ischemic injury during the acute phase of ischemia. Due to the fact, that conventional MR-imaging in the early phase of global hypoxia often shows normal results, we tested the prognostic value of DWI during the early phase of global hypoxia. Method: In a prospective study DWI was performed in 15 patients within 36hours after global cerebral hypoxia. Results of DWI were analyzed by blinded neuroradiologists and compared to results of somatosensory evoked potentials (SEP) and the clinical outcome (Coma Remmission Scale) after 6 months. Results: Three patients without distinctive feature either for conventional nor for DWI showed normal results for somatosensory evoked potentials and good recovery of the clinical symptoms after 6 months. Of the remaining 12 patients conventional MR-imaging showed normal results in 10. In 2/12 patients slight hyperintense areas in the basalganglia and increasing brain edema were found. However, DWI showed in all patients different expressed hyperintense areas in the basal ganglia, the parietal and occipital cortex and the cerebellum with a marked ADC decrease. Only small hyperintense areas with less ADC decrease could be observed in the frontal lobe. SEPs were bilaterally absent in 3/12 patients. 2/12 revealed absent cortical SEP on one side, whereas 3/12 showed a pathological latency time or amplitude. The remaining (4/12) revealed regular SEP. All of these 12 patients developed an apallic syndrome, confirmed by the clinical control investigation after 6 months. Conclusion: The preliminary results of our prospective study indicate that DWI during the early phase of global cerebral hypoxia seems to be a predictor for clinical outcome. However, more patients are needed for further evaluation.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.20-9.30
Room: Auditorium II
Diffusion-weighted MR-imaging during the early phase of global cerebral hypoxia: a predictor for clinical outcome?
T. Els
J. Klisch
R. Kubalek
J. Kassubek
M. Herpers
C.H.Lucking
GERMANY
University of Freiburg
Background and purpose: Due to the improvement of intensive care medicine, an increasing number of patients develop an acute vegetative state following global cerebral hypoxia in cardiac arrest - the estimated number for Germany might be 3000/a. Prognostic assessment in clinical routine is often difficult. Diffusion-weighted imaging (DWI) is sensitive for ischemia dependent watershifts between the extra- and intracellular compartments. With respect to some limitations DWI is the method of choice to deline severe ischemic injury during the acute phase of ischemia. Due to the fact, that conventional MR-imaging in the early phase of global hypoxia often shows normal results, we tested the prognostic value of DWI during the early phase of global hypoxia. Method: In a prospective study DWI was performed in 15 patients within 36hours after global cerebral hypoxia. Results of DWI were analyzed by blinded neuroradiologists and compared to results of somatosensory evoked potentials (SEP) and the clinical outcome (Coma Remmission Scale) after 6 months. Results: Three patients without distinctive feature either for conventional nor for DWI showed normal results for somatosensory evoked potentials and good recovery of the clinical symptoms after 6 months. Of the remaining 12 patients conventional MR-imaging showed normal results in 10. In 2/12 patients slight hyperintense areas in the basalganglia and increasing brain edema were found. However, DWI showed in all patients different expressed hyperintense areas in the basal ganglia, the parietal and occipital cortex and the cerebellum with a marked ADC decrease. Only small hyperintense areas with less ADC decrease could be observed in the frontal lobe. SEPs were bilaterally absent in 3/12 patients. 2/12 revealed absent cortical SEP on one side, whereas 3/12 showed a pathological latency time or amplitude. The remaining (4/12) revealed regular SEP. All of these 12 patients developed an apallic syndrome, confirmed by the clinical control investigation after 6 months. Conclusion: The preliminary results of our prospective study indicate that DWI during the early phase of global cerebral hypoxia seems to be a predictor for clinical outcome. However, more patients are needed for further evaluation.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.20-9.30
Room: Auditorium II
Diffusion-weighted MR-imaging during the early phase of global cerebral hypoxia: a predictor for clinical outcome?
T. Els
J. Klisch
R. Kubalek
J. Kassubek
M. Herpers
C.H.Lucking
GERMANY
University of Freiburg
Background and purpose: Due to the improvement of intensive care medicine, an increasing number of patients develop an acute vegetative state following global cerebral hypoxia in cardiac arrest - the estimated number for Germany might be 3000/a. Prognostic assessment in clinical routine is often difficult. Diffusion-weighted imaging (DWI) is sensitive for ischemia dependent watershifts between the extra- and intracellular compartments. With respect to some limitations DWI is the method of choice to deline severe ischemic injury during the acute phase of ischemia. Due to the fact, that conventional MR-imaging in the early phase of global hypoxia often shows normal results, we tested the prognostic value of DWI during the early phase of global hypoxia. Method: In a prospective study DWI was performed in 15 patients within 36hours after global cerebral hypoxia. Results of DWI were analyzed by blinded neuroradiologists and compared to results of somatosensory evoked potentials (SEP) and the clinical outcome (Coma Remmission Scale) after 6 months. Results: Three patients without distinctive feature either for conventional nor for DWI showed normal results for somatosensory evoked potentials and good recovery of the clinical symptoms after 6 months. Of the remaining 12 patients conventional MR-imaging showed normal results in 10. In 2/12 patients slight hyperintense areas in the basalganglia and increasing brain edema were found. However, DWI showed in all patients different expressed hyperintense areas in the basal ganglia, the parietal and occipital cortex and the cerebellum with a marked ADC decrease. Only small hyperintense areas with less ADC decrease could be observed in the frontal lobe. SEPs were bilaterally absent in 3/12 patients. 2/12 revealed absent cortical SEP on one side, whereas 3/12 showed a pathological latency time or amplitude. The remaining (4/12) revealed regular SEP. All of these 12 patients developed an apallic syndrome, confirmed by the clinical control investigation after 6 months. Conclusion: The preliminary results of our prospective study indicate that DWI during the early phase of global cerebral hypoxia seems to be a predictor for clinical outcome. However, more patients are needed for further evaluation.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.20-9.30
Room: Auditorium II
Diffusion-weighted MR-imaging during the early phase of global cerebral hypoxia: a predictor for clinical outcome?
T. Els
J. Klisch
R. Kubalek
J. Kassubek
M. Herpers
C.H.Lucking
GERMANY
University of Freiburg
Background and purpose: Due to the improvement of intensive care medicine, an increasing number of patients develop an acute vegetative state following global cerebral hypoxia in cardiac arrest - the estimated number for Germany might be 3000/a. Prognostic assessment in clinical routine is often difficult. Diffusion-weighted imaging (DWI) is sensitive for ischemia dependent watershifts between the extra- and intracellular compartments. With respect to some limitations DWI is the method of choice to deline severe ischemic injury during the acute phase of ischemia. Due to the fact, that conventional MR-imaging in the early phase of global hypoxia often shows normal results, we tested the prognostic value of DWI during the early phase of global hypoxia. Method: In a prospective study DWI was performed in 15 patients within 36hours after global cerebral hypoxia. Results of DWI were analyzed by blinded neuroradiologists and compared to results of somatosensory evoked potentials (SEP) and the clinical outcome (Coma Remmission Scale) after 6 months. Results: Three patients without distinctive feature either for conventional nor for DWI showed normal results for somatosensory evoked potentials and good recovery of the clinical symptoms after 6 months. Of the remaining 12 patients conventional MR-imaging showed normal results in 10. In 2/12 patients slight hyperintense areas in the basalganglia and increasing brain edema were found. However, DWI showed in all patients different expressed hyperintense areas in the basal ganglia, the parietal and occipital cortex and the cerebellum with a marked ADC decrease. Only small hyperintense areas with less ADC decrease could be observed in the frontal lobe. SEPs were bilaterally absent in 3/12 patients. 2/12 revealed absent cortical SEP on one side, whereas 3/12 showed a pathological latency time or amplitude. The remaining (4/12) revealed regular SEP. All of these 12 patients developed an apallic syndrome, confirmed by the clinical control investigation after 6 months. Conclusion: The preliminary results of our prospective study indicate that DWI during the early phase of global cerebral hypoxia seems to be a predictor for clinical outcome. However, more patients are needed for further evaluation.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.20-9.30
Room: Auditorium II
Diffusion-weighted MR-imaging during the early phase of global cerebral hypoxia: a predictor for clinical outcome?
T. Els
J. Klisch
R. Kubalek
J. Kassubek
M. Herpers
C.H.Lucking
GERMANY
University of Freiburg
Background and purpose: Due to the improvement of intensive care medicine, an increasing number of patients develop an acute vegetative state following global cerebral hypoxia in cardiac arrest - the estimated number for Germany might be 3000/a. Prognostic assessment in clinical routine is often difficult. Diffusion-weighted imaging (DWI) is sensitive for ischemia dependent watershifts between the extra- and intracellular compartments. With respect to some limitations DWI is the method of choice to deline severe ischemic injury during the acute phase of ischemia. Due to the fact, that conventional MR-imaging in the early phase of global hypoxia often shows normal results, we tested the prognostic value of DWI during the early phase of global hypoxia. Method: In a prospective study DWI was performed in 15 patients within 36hours after global cerebral hypoxia. Results of DWI were analyzed by blinded neuroradiologists and compared to results of somatosensory evoked potentials (SEP) and the clinical outcome (Coma Remmission Scale) after 6 months. Results: Three patients without distinctive feature either for conventional nor for DWI showed normal results for somatosensory evoked potentials and good recovery of the clinical symptoms after 6 months. Of the remaining 12 patients conventional MR-imaging showed normal results in 10. In 2/12 patients slight hyperintense areas in the basalganglia and increasing brain edema were found. However, DWI showed in all patients different expressed hyperintense areas in the basal ganglia, the parietal and occipital cortex and the cerebellum with a marked ADC decrease. Only small hyperintense areas with less ADC decrease could be observed in the frontal lobe. SEPs were bilaterally absent in 3/12 patients. 2/12 revealed absent cortical SEP on one side, whereas 3/12 showed a pathological latency time or amplitude. The remaining (4/12) revealed regular SEP. All of these 12 patients developed an apallic syndrome, confirmed by the clinical control investigation after 6 months. Conclusion: The preliminary results of our prospective study indicate that DWI during the early phase of global cerebral hypoxia seems to be a predictor for clinical outcome. However, more patients are needed for further evaluation.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.20-9.30
Room: Auditorium II
Diffusion-weighted MR-imaging during the early phase of global cerebral hypoxia: a predictor for clinical outcome?
T. Els
J. Klisch
R. Kubalek
J. Kassubek
M. Herpers
C.H.Lucking
GERMANY
University of Freiburg
Background and purpose: Due to the improvement of intensive care medicine, an increasing number of patients develop an acute vegetative state following global cerebral hypoxia in cardiac arrest - the estimated number for Germany might be 3000/a. Prognostic assessment in clinical routine is often difficult. Diffusion-weighted imaging (DWI) is sensitive for ischemia dependent watershifts between the extra- and intracellular compartments. With respect to some limitations DWI is the method of choice to deline severe ischemic injury during the acute phase of ischemia. Due to the fact, that conventional MR-imaging in the early phase of global hypoxia often shows normal results, we tested the prognostic value of DWI during the early phase of global hypoxia. Method: In a prospective study DWI was performed in 15 patients within 36hours after global cerebral hypoxia. Results of DWI were analyzed by blinded neuroradiologists and compared to results of somatosensory evoked potentials (SEP) and the clinical outcome (Coma Remmission Scale) after 6 months. Results: Three patients without distinctive feature either for conventional nor for DWI showed normal results for somatosensory evoked potentials and good recovery of the clinical symptoms after 6 months. Of the remaining 12 patients conventional MR-imaging showed normal results in 10. In 2/12 patients slight hyperintense areas in the basalganglia and increasing brain edema were found. However, DWI showed in all patients different expressed hyperintense areas in the basal ganglia, the parietal and occipital cortex and the cerebellum with a marked ADC decrease. Only small hyperintense areas with less ADC decrease could be observed in the frontal lobe. SEPs were bilaterally absent in 3/12 patients. 2/12 revealed absent cortical SEP on one side, whereas 3/12 showed a pathological latency time or amplitude. The remaining (4/12) revealed regular SEP. All of these 12 patients developed an apallic syndrome, confirmed by the clinical control investigation after 6 months. Conclusion: The preliminary results of our prospective study indicate that DWI during the early phase of global cerebral hypoxia seems to be a predictor for clinical outcome. However, more patients are needed for further evaluation.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.30-9.40
Room: Auditorium II
Window narrowing - a new method for standardized assessment of the ischemic centre in CT based brain perfusion maps
D.G.Nabavi
S.P.Kloska
E.M.Nam
A. Allroggen
E. Klotz
W. Heindel
E.B.Ringelstein
GERMANY
University Hospital of Münster
Background: Mapping of brain perfusion is used to assess the severity of brain ischemia in acute stroke. The ultimate goal is to distinguish already infarcted from still salvageable tissue. Most perfusion computed tomography (PCT) methods can readily depict the total ischemic area, however, they do not allow to identify the ischemic centre (IC) with sufficient reliability. Methods: We analysed 76 PCT-maps of cerebral blood flow (CBF) and cerebral blood volume (CBV) in 40 acute stroke patients using multislice CT technology (SOMATOM VolumeZoom, Siemens). For standardized display of the IC, the window of the color maps was narrowed until “homogenisation” of the contralateral (unaffected) hemisphere was reached. Thereby, tissue without or with only mild to moderate ischemia is displayed in unique color. Tissue still depictable after completed homogenisation was defined as the IC. We analysed (i) presence and size of the IC on PCT-maps, (ii) their relative perfusion values by comparison with contralateral, mirrored tissue, and (iii) their correlation with occurrence and size of cerebral infarction on follow-up imaging. Results: Tissue ischemia was visible in 64 % and 58.9 % of CBF and CBV maps. After window narrowing, an IC was present in 56.8 % and 54.1 % of slices. The mean size of the IC comprised 11.9 +/- 14.7 % (CBF) and 11.6 +/-15.2 % (CBV) of the ipsilateral hemisphere. The relative perfusion values were 0.38(CBF) and 0.43 (CBV) for the entire ischemic area and 0.11 (CBF) and 0.13 (CBV) for the IC. The size of the IC correlated well with the final infarction size (r = 0.75-0.82, p < 0,01). With respect to occurrence of cerebral infarction, presence of an IC on CBF maps showed the best positive (97.9 %) and negative (72.7 %) predcitability. Discussion: On relative PCT-maps, window narrowing provides an operator-independent depiction of the IC in acute stroke patients. This technique may allow for mismatch-imaging with CT technology in hyperacute stroke.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.40-9.50
Room: Auditorium II
The ischaemic penumbra in white and grey matter of brain after ischaemic stroke; an 18FMISO PET study
A.LE.FALCAO
D.C.REUTENS
R. MARKUS
T. PHAN
P. WRIGHT
S.J.READ
H. TOCHON-DANGUY
J. SACHINIDIS
D.W.HOWELLS
G.A.DONNAN
AUSTRALIA
NATIONAL STROKE RESEARCH INSTITUTE
Background: Neuroprotective therapies have not been translated successfully from animal models to humans. In animal models, the white matter compartment is small and has a different neurochemical response to ischaemia than grey matter. White matter in humans forms a larger proportion of brain (50%) and maybe responsible for neuroprotection failures. There is uncertainty as to whether the penumbra exists in white matter of humans with ischaemic stroke. We have investigated this matter using 18FMISO PET as a penumbral marker in patients with recent onset ischaemic stroke. Methods: Patients presenting within 48 hours of ischaemic stroke had an 18FMISO PET performed. Initial CT was repeated at 7-10 days. Infarcted and penumbral voxels from CT and PET images were coregistered to standard space and then to a probabilistic MR map of grey and white matter validated against 20 stroke age matched controls. The distribution of volumes of penumbra, final infarct and initial "at risk tissue" in grey and white matter was determined. Results: 28 patients with acute ischaemic stroke were studied (M17, F11 ; mean +/- SD 73.5 +/- 5 yrs) who had increased 18FMISO uptake as well as 20 controls (72+/-4 yrs). Penumbral tissue was observed in both grey matter (median 5.9, interquartile range 0.6-20.7cm3, 34.9%) and white matter (11.0, 1.3-27.0 cm3, 65.1%, p=0.23) While there was a greater volume of initial "at risk tissue" in grey matter (53.0 cm3, 37.6-103.1 vs 43.3 cm3, 22.0-86.0; p<0.001), at the time of PET imaging, a higher proportion of this was penumbral in white matter (white 29.9%, 4.3-66.6; grey 21.7%, 2.9-56.8, p=.018). Discussion: There is now clear evidence that the ischaemic penumbra exists in white matter of humans with acute ischaemic stroke. Since a greater proportion of the initially “at risk tissue” within white matter compared to grey was still penumbral at the time of imaging, this may suggest a greater white matter resistance to ischaemia. The presence of penumbra means that ischemic white matter is potentially salvageable but more specific therapies may be needed to do so.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.50-10.00
Room: Auditorium II
Hemodynamic assessment by diffusion-weighted MRI, proton MR spectroscopic imaging and SPECT in symptomatic patients due to the occlusive major-vessel
K. Kamada
K. Mitsumori
T. Shogo
I. Yoshinobu
JAPAN
Chitose City Hospital
Background: Cerebral hemodynamic status has been reported to a critical ischemic condition to dramatically influence the occurrence and outcome of acute stroke. The purpose of this study was to assess hemodynamic compromis, comparing ischemic patterns on diffusion-weighted MRI (DWI), metabolic profiles on proton MR spectroscopic imaging (1H MRSI) and ischemic severity on SPECT. Methods: Twenty-four patients who had experienced a transient ischemic attack or minor stroke, showing hemispheric ischemia on SPECT due to the occlusive major-vessel disease were examined within 6 hours after onset. The ischemic patterns on DWI were visually evaluated and peak areas of lactate and N-acetyl aspartate (NAA) were calculated from volumes of interest in the hemodynamic state. Cerebral blood flow (CBF) and cerebrovascular reactivity (rCVR) to acetazolamide were quantitatively determined by (133)Xe SEPCT in 17 of 24 patients. Results: DWI consistently demonstrated scattered high-intense spots in the middle cerebral artery (MCA) border zone while (133)Xe SEPCT revealed significantly decreased CBF (less than 28 ml/min/100g) in the whole MCA territory and decreased rCVR (less than 10 %) in 10 of 17 patients. 1H MRSI detected only slight accumulation of Lac with no NAA reduction. Fourteen patients with the scattered spots in the anterior and posterior border zones revealed marked neurological deterioration. Revasculization performed within a few days after onset, could effectively prevent the stroke progression. Discussion: DWI is a noninvasive and rapid method for evaluating the ischemic conditions and gives us useful information for patient management. Scattered spots in the whole MCA territory on DWI is the initial sign of the stroke progression in patients with hemodynamic ischemia.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.50-10.00
Room: Auditorium II
Hemodynamic assessment by diffusion-weighted MRI, proton MR spectroscopic imaging and SPECT in symptomatic patients due to the occlusive major-vessel
K. Kamada
K. Mitsumori
T. Shogo
I. Yoshinobu
JAPAN
Chitose City Hospital
Background: Cerebral hemodynamic status has been reported to a critical ischemic condition to dramatically influence the occurrence and outcome of acute stroke. The purpose of this study was to assess hemodynamic compromis, comparing ischemic patterns on diffusion-weighted MRI (DWI), metabolic profiles on proton MR spectroscopic imaging (1H MRSI) and ischemic severity on SPECT. Methods: Twenty-four patients who had experienced a transient ischemic attack or minor stroke, showing hemispheric ischemia on SPECT due to the occlusive major-vessel disease were examined within 6 hours after onset. The ischemic patterns on DWI were visually evaluated and peak areas of lactate and N-acetyl aspartate (NAA) were calculated from volumes of interest in the hemodynamic state. Cerebral blood flow (CBF) and cerebrovascular reactivity (rCVR) to acetazolamide were quantitatively determined by (133)Xe SEPCT in 17 of 24 patients. Results: DWI consistently demonstrated scattered high-intense spots in the middle cerebral artery (MCA) border zone while (133)Xe SEPCT revealed significantly decreased CBF (less than 28 ml/min/100g) in the whole MCA territory and decreased rCVR (less than 10 %) in 10 of 17 patients. 1H MRSI detected only slight accumulation of Lac with no NAA reduction. Fourteen patients with the scattered spots in the anterior and posterior border zones revealed marked neurological deterioration. Revasculization performed within a few days after onset, could effectively prevent the stroke progression. Discussion: DWI is a noninvasive and rapid method for evaluating the ischemic conditions and gives us useful information for patient management. Scattered spots in the whole MCA territory on DWI is the initial sign of the stroke progression in patients with hemodynamic ischemia.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.50-10.00
Room: Auditorium II
Hemodynamic assessment by diffusion-weighted MRI, proton MR spectroscopic imaging and SPECT in symptomatic patients due to the occlusive major-vessel
K. Kamada
K. Mitsumori
T. Shogo
I. Yoshinobu
JAPAN
Chitose City Hospital
Background: Cerebral hemodynamic status has been reported to a critical ischemic condition to dramatically influence the occurrence and outcome of acute stroke. The purpose of this study was to assess hemodynamic compromis, comparing ischemic patterns on diffusion-weighted MRI (DWI), metabolic profiles on proton MR spectroscopic imaging (1H MRSI) and ischemic severity on SPECT. Methods: Twenty-four patients who had experienced a transient ischemic attack or minor stroke, showing hemispheric ischemia on SPECT due to the occlusive major-vessel disease were examined within 6 hours after onset. The ischemic patterns on DWI were visually evaluated and peak areas of lactate and N-acetyl aspartate (NAA) were calculated from volumes of interest in the hemodynamic state. Cerebral blood flow (CBF) and cerebrovascular reactivity (rCVR) to acetazolamide were quantitatively determined by (133)Xe SEPCT in 17 of 24 patients. Results: DWI consistently demonstrated scattered high-intense spots in the middle cerebral artery (MCA) border zone while (133)Xe SEPCT revealed significantly decreased CBF (less than 28 ml/min/100g) in the whole MCA territory and decreased rCVR (less than 10 %) in 10 of 17 patients. 1H MRSI detected only slight accumulation of Lac with no NAA reduction. Fourteen patients with the scattered spots in the anterior and posterior border zones revealed marked neurological deterioration. Revasculization performed within a few days after onset, could effectively prevent the stroke progression. Discussion: DWI is a noninvasive and rapid method for evaluating the ischemic conditions and gives us useful information for patient management. Scattered spots in the whole MCA territory on DWI is the initial sign of the stroke progression in patients with hemodynamic ischemia.
Neuroimaging: MRI and fMRI
Presentation:Oral
May 24th 2003
9.50-10.00
Room: Auditorium II
Hemodynamic assessment by diffusion-weighted MRI, proton MR spectroscopic imaging and SPECT in symptomatic patients due to the occlusive major-vessel
K. Kamada
K. Mitsumori
T. Shogo
I. Yoshinobu
JAPAN
Chitose City Hospital
Background: Cerebral hemodynamic status has been reported to a critical ischemic condition to dramatically influence the occurrence and outcome of acute stroke. The purpose of this study was to assess hemodynamic compromis, comparing ischemic patterns on diffusion-weighted MRI (DWI), metabolic profiles on proton MR spectroscopic imaging (1H MRSI) and ischemic severity on SPECT. Methods: Twenty-four patients who had experienced a transient ischemic attack or minor stroke, showing hemispheric ischemia on SPECT due to the occlusive major-vessel disease were examined within 6 hours after onset. The ischemic patterns on DWI were visually evaluated and peak areas of lactate and N-acetyl aspartate (NAA) were calculated from volumes of interest in the hemodynamic state. Cerebral blood flow (CBF) and cerebrovascular reactivity (rCVR) to acetazolamide were quantitatively determined by (133)Xe SEPCT in 17 of 24 patients. Results: DWI consistently demonstrated scattered high-intense spots in the middle cerebral artery (MCA) border zone while (133)Xe SEPCT revealed significantly decreased CBF (less than 28 ml/min/100g) in the whole MCA territory and decreased rCVR (less than 10 %) in 10 of 17 patients. 1H MRSI detected only slight accumulation of Lac with no NAA reduction. Fourteen patients with the scattered spots in the anterior and posterior border zones revealed marked neurological deterioration. Revasculization performed within a few days after onset, could effectively prevent the stroke progression. Discussion: DWI is a noninvasive and rapid method for evaluating the ischemic conditions and gives us useful information for patient management. Scattered spots in the whole MCA territory on DWI is the initial sign of the stroke progression in patients with hemodynamic ischemia.
Stroke in the world
Presentation:Oral
May 22nd 2003
11.50-12.00
Room: Auditorium I
Comparison of worldwide First-ever-in-a-lifetime (FES) stroke incidence risk: implications for current and future stroke incidence
P. Syme
A. Byrne
R. Chen
A. Finlayson
UNITED KINGDOM
Borders General Hospital, University of Edinburgh
Here we compare incidence risk in 18 incidence studies, completed over the last 20 years, with that of the Scottish Borders Stroke Study(SBSS). We determined the overall contribution of risk to crude incidence and how this risk had changed over the last 20 years. From this we have developed prediction models for FES and have tested them on Scottish and Australian national stroke datasets. Methods/Results: Logistic regression was used to estimate the odds ratios (OR) for 18 incidence studies compared with the SBSS (OR=1). The odds ratios ranged from .689 (95% CI, .619-.770) (P<0.001) to 1.441 (95%CI,1.259-1.650) (P<0.001). There was no trend found in OR over the last 20 years. 6 study populations had a significantly lower, 2 a higher and 10 the same risk as the SBSS. An estimate was made of the male and female incidence due to the percentage of elderly in each poulation (age-dependent incidence, ADI). Residuals were obtained from the regression of total ADI and crude incidence (crude incidence due to age-adjusted risk). These residuals were plotted against OR, R=.940. 10 out of the 18 studies had 95%CI which included an OR of .9336 corresponding to a zero residual. The SBSS ADI estimate of FES was then plotted against 20 years of FES in Scotland, R square .97 and all cerebrovascular admissions for Australia, R square .9912. Conclusions: We have demonstrated significant differences in age-adjusted risk worldwide. However, we have shown that risk contributes little to crude incidence which can be accurately estimated by ADI for most populations. Furthermore, incidence risk has not declined over the last 20 years of incidence studies. As a result, we anticipate a massive increase in stroke incidence over the next 50 years due to anticipated population ageing.
Stroke in the world
Presentation:Oral
May 22nd 2003
11.50-12.00
Room: Auditorium I
Comparison of worldwide First-ever-in-a-lifetime (FES) stroke incidence risk: implications for current and future stroke incidence
P. Syme
A. Byrne
R. Chen
A. Finlayson
UNITED KINGDOM
Borders General Hospital, University of Edinburgh
Here we compare incidence risk in 18 incidence studies, completed over the last 20 years, with that of the Scottish Borders Stroke Study(SBSS). We determined the overall contribution of risk to crude incidence and how this risk had changed over the last 20 years. From this we have developed prediction models for FES and have tested them on Scottish and Australian national stroke datasets. Methods/Results: Logistic regression was used to estimate the odds ratios (OR) for 18 incidence studies compared with the SBSS (OR=1). The odds ratios ranged from .689 (95% CI, .619-.770) (P<0.001) to 1.441 (95%CI,1.259-1.650) (P<0.001). There was no trend found in OR over the last 20 years. 6 study populations had a significantly lower, 2 a higher and 10 the same risk as the SBSS. An estimate was made of the male and female incidence due to the percentage of elderly in each poulation (age-dependent incidence, ADI). Residuals were obtained from the regression of total ADI and crude incidence (crude incidence due to age-adjusted risk). These residuals were plotted against OR, R=.940. 10 out of the 18 studies had 95%CI which included an OR of .9336 corresponding to a zero residual. The SBSS ADI estimate of FES was then plotted against 20 years of FES in Scotland, R square .97 and all cerebrovascular admissions for Australia, R square .9912. Conclusions: We have demonstrated significant differences in age-adjusted risk worldwide. However, we have shown that risk contributes little to crude incidence which can be accurately estimated by ADI for most populations. Furthermore, incidence risk has not declined over the last 20 years of incidence studies. As a result, we anticipate a massive increase in stroke incidence over the next 50 years due to anticipated population ageing.
Stroke in the world
Presentation:Oral
May 22nd 2003
11.50-12.00
Room: Auditorium I
Comparison of worldwide First-ever-in-a-lifetime (FES) stroke incidence risk: implications for current and future stroke incidence
P. Syme
A. Byrne
R. Chen
A. Finlayson
UNITED KINGDOM
Borders General Hospital, University of Edinburgh
Here we compare incidence risk in 18 incidence studies, completed over the last 20 years, with that of the Scottish Borders Stroke Study(SBSS). We determined the overall contribution of risk to crude incidence and how this risk had changed over the last 20 years. From this we have developed prediction models for FES and have tested them on Scottish and Australian national stroke datasets. Methods/Results: Logistic regression was used to estimate the odds ratios (OR) for 18 incidence studies compared with the SBSS (OR=1). The odds ratios ranged from .689 (95% CI, .619-.770) (P<0.001) to 1.441 (95%CI,1.259-1.650) (P<0.001). There was no trend found in OR over the last 20 years. 6 study populations had a significantly lower, 2 a higher and 10 the same risk as the SBSS. An estimate was made of the male and female incidence due to the percentage of elderly in each poulation (age-dependent incidence, ADI). Residuals were obtained from the regression of total ADI and crude incidence (crude incidence due to age-adjusted risk). These residuals were plotted against OR, R=.940. 10 out of the 18 studies had 95%CI which included an OR of .9336 corresponding to a zero residual. The SBSS ADI estimate of FES was then plotted against 20 years of FES in Scotland, R square .97 and all cerebrovascular admissions for Australia, R square .9912. Conclusions: We have demonstrated significant differences in age-adjusted risk worldwide. However, we have shown that risk contributes little to crude incidence which can be accurately estimated by ADI for most populations. Furthermore, incidence risk has not declined over the last 20 years of incidence studies. As a result, we anticipate a massive increase in stroke incidence over the next 50 years due to anticipated population ageing.