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*Only for medical professionals to read and refer to the NCN 2021 exciting content express, not to be missed.
CT perfusion scan (CTP) is mainly used to assess cerebral blood flow and cerebral metabolism
.
It is widely used in patients with acute ischemic cerebral infarction .
At the 24th National Conference on Neurology (NCN) of the Chinese Medical Association, Professor Cheng Xin from the Department of Neurology, Huashan Hospital Affiliated to Fudan University, asked "Can CTP predict the prognosis of acute lacunar infarction?" 》A wonderful report! 1What is CTP? While intravenous injection of contrast agent, continuous dynamic scanning is performed on the selected layer of interest to obtain the time-density curve (TDC) of each pixel in the selected layer, and according to this curve, it is converted and converted by different mathematical models.
Computer pseudo-color processing to obtain regional cerebral blood volume (cercbral blood volume, CBV), cerebral blood flow (cercbral blood flow, CBF), mean transit time (MTT) of contrast agent, peak time of contrast agent (time to peak, TTP) and other hemodynamic parameters and perfusion image performance, it is a kind of functional imaging to evaluate the perfusion state of brain tissue
.
There is another perfusion time delay parameter, Delay Time (DT)
.
What is the diagnostic value of 2CTP? Cerebral perfusion imaging is mainly used to assess cerebral blood flow and brain metabolism.
The ischemic penumbra refers to brain tissue that can be rescued clinically
.
CTP has high accuracy in detecting acute infarction and ischemic penumbra, and has been widely used in clinical treatment decision-making for acute ischemic stroke
.
In actual clinical applications, there are post-processing software such as RAPID and MIStar.
They all define the area with Tmax greater than 6 seconds or DT> 3 seconds as penumbra (low perfusion area); areas with CBF <30% or more are regarded as core infarcts (Core)
.
Professor Cheng emphasized on the diagnostic value of CTP as follows: increase diagnostic confidence-is it a stroke-like episode? According to CTP, the risk stratification of light stroke is carried out; it is easier to identify abnormal perfusion than to identify occluded blood vessels; distal vascular occlusion is more sensitive than CTA; CTP can quantitatively assess collaterals; it can save ischemic penumbra vs necrotic tissue: CTA collateral assessment is more convenient; it increases the confidence in communication and decision-making with the patient’s family; avoids unnecessary endovascular treatment; broadens the treatment time window; predicts bleeding transformation
.
Application of 3CTP in Acute Lacunar Infarction In acute ischemic stroke, about 40% of patients have obvious hypoperfusion on CTP, but there are still 60% of patients who do not see obvious blood flow hypoperfusion, and a large part of it may be lacunar For patients with cerebral infarction, what is the value of CTP in acute cavitary infarction? Previous studies have mostly focused on how to identify acute luminal infarction on CTP.
Because CTP has a poor signal-to-noise ratio and thicker layer, if the lesion is small, it is likely to miss the lesion
.
How does CTP recognize cavitary infarction: ①CTP is better than CT plain scan + CTA; ②but it has low sensitivity and high specificity; ③MTT may be the most sensitive index
.
4 CTP in acute lamina infarction related research Since CTP is not sensitive to acute lamina infarction
.
Then: 1) Through the precise overlap of DWI and CTP at the same level, can the parameters of baseline CTP of infarct focus predict the prognosis of acute cavitary infarction? 2) Can intravenous alteplase (rt-PA) thrombolysis improve the perfusion of acute luminal infarction, thereby improving the prognosis of patients? For the above-mentioned scientific issues, the team of Professor Cheng Xin from Huashan Hospital conducted a retrospective study
.
A total of 959 patients with acute ischemic stroke who completed CTP in the emergency department from 2011.
11 to 2020.
12 in Huashan Hospital from 2011.
11 to 2020.
12 and had a DWI examination within 7 days were included, except for non-caval infarction, posterior circulation, severe stenosis of ipsilateral large vessels, and suspicious cardiogenic thrombosis.
Source patients, 71 patients with acute anterior circulation cavity infarction were eventually included in this study
.
The CTP original image and the DWI image of the same level are overlapped and calibrated to calculate the acute infarction, the contralateral mirror area of the acute infarction and the contralateral hemisphere perfusion parameters, including voxel-based CBF, CBV, MTT, DT
.
The relative perfusion parameter is defined as the ratio of the perfusion parameter of the acute infarction and the perfusion parameter of the contralateral mirror image area
.
The perfusion parameters and clinical outcomes as well as their interaction with intravenous thrombolysis were studied
.
At the same time, the perfusion parameters of patients undergoing perfusion CT before thrombolysis and those undergoing perfusion CT after thrombolysis were also compared
.
The mRS 0-1 in March was defined as a good prognosis
.
The results found: 1) A univariate comparison of good prognosis and poor prognosis after 3 months, age, gender, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline systolic blood pressure, baseline diastolic blood pressure, previous hypertension, and previous Diabetes, lesion size, white matter hyperintensity, no statistical significance
.
2) The multivariate stepwise regression model also included clinically relevant variables, and the contralateral hemisphere CBF was an independent predictor of a good prognosis in 3 months
.
3) After the baseline NIHSS is corrected, the higher CBF of the contralateral cerebral hemisphere is correlated with the smaller infarct volume
.
4) There is an interaction between rt-PA and CBF in the contralateral cerebral hemisphere for good prognosis in 3 months
.
The contralateral hemisphere CBF is in the range of 17.
6-24.
9 ml/mg/min.
Intravenous thrombolysis can improve the prognosis of patients with acute cavitary infarction.
If the contralateral hemisphere CBF is too low or too high, intravenous thrombolysis has no significant effect on the prognosis
.
5) There was no difference in baseline clinical and imaging data between patients who underwent CTP after thrombolysis and CTP before thrombolysis.
Compared with patients who underwent CTP before thrombolysis, more patients showed rCBF>1, P=0.
03, tPA can improve local blood perfusion in acute luminal infarction
.
As the time from onset to CTP imaging in patients with acute infarction increases, CBF and CBV gradually decrease, which proves that patients with acute infarction have collaterals
.
Of course, Professor Cheng also mentioned that this study is a single-center study, with a small sample, 10 people have no prognostic information, and there are certain limitations
.
Finally, the study concluded that: the contralateral cerebral hemisphere perfusion determines the prognosis of patients with acute luminal infarction in 3 months; the contralateral cerebral hemisphere perfusion determines the 3-month prognosis of patients with acute luminal infarction by tPA; the patients with CTP examination after tPA thrombolysis have more manifestations The local rCBF>1, P=0.
03.
tPA can improve the local blood perfusion of acute luminal infarction
.
This study shows that for patients with acute luminal infarction, the CBF of the contralateral hemisphere is an independent predictor of clinical prognosis, which again shows that cerebral small vessel disease is a disease of the whole brain, and the prognosis may be determined by the patient's own blood perfusion
.
The CBF of the contralateral hemisphere interacts with intravenous thrombolysis.
The CBF of the contralateral hemisphere is too low, even if intravenous thrombolysis cannot improve the prognosis, and the CBF of the contralateral hemisphere is too high, indicating that the patient's own collateral compensation is better and may not need veins.
Thrombolysis can also achieve a better prognosis
.
This study has been published (Lan Hong, Yifeng Ling, Ya Su, Lumeng Yan, Longting Lin, Mark Parsons, Xin Cheng, Qiang Dong.
Hemispheric cerebral blood flow predicts outcome in acute small subcortical infarcts.
J Cereb Blood Flow Metab.
2021 Aug 26 ;271678X211029884)
.
Expert Profile Cheng Xin Chief Physician Doctor of Medicine, Chief Physician of Neurology Department of Huashan Hospital Affiliated to Fudan University, Associate Professor, Postgraduate Tutor of Shanghai Youth Science and Technology Star, Young Top Talent Chinese Medical Association Neurology Branch Committee of Cerebrovascular Diseases, Chinese Stroke Society Deputy Chairman of Cerebral Small Vascular Disease Branch, Standing Committee of Cerebral Blood Flow and Metabolism Branch of Chinese Stroke Society, Standing Committee of Cerebrovascular Diseases Committee, National Health Commission, Cerebral Prevention Committee, Standing Committee of Cerebrovascular Diseases Committee, National Health Commission, Cerebral Defense Committee, Standing Committee, Youth Committee, Shanghai Medical Association, Science Popularization Branch, Youth Committee Vice-Chairman: The Youth Committee of the Neurology Specialist Branch of the Shanghai Medical Association Mainly focuses on the acute phase imaging and treatment of stroke, clinical and basic research on cerebral small vessel disease, and presides over the provincial and ministerial projects such as the National Natural Science Foundation of China, the Ministry of Education, and the Shanghai Science and Technology Commission6 As the backbone of the project, he participated in 2 key R&D programs of the Ministry of Science and Technology and was invited to publish reviews in Lancet Neurology.
As the first or corresponding author, he published more than 30 articles in domestic and foreign journals such as Annals of Neurology, Neurology, and edited 1 monograph.
4 consensus/standards of industry associations in this field
CT perfusion scan (CTP) is mainly used to assess cerebral blood flow and cerebral metabolism
.
It is widely used in patients with acute ischemic cerebral infarction .
At the 24th National Conference on Neurology (NCN) of the Chinese Medical Association, Professor Cheng Xin from the Department of Neurology, Huashan Hospital Affiliated to Fudan University, asked "Can CTP predict the prognosis of acute lacunar infarction?" 》A wonderful report! 1What is CTP? While intravenous injection of contrast agent, continuous dynamic scanning is performed on the selected layer of interest to obtain the time-density curve (TDC) of each pixel in the selected layer, and according to this curve, it is converted and converted by different mathematical models.
Computer pseudo-color processing to obtain regional cerebral blood volume (cercbral blood volume, CBV), cerebral blood flow (cercbral blood flow, CBF), mean transit time (MTT) of contrast agent, peak time of contrast agent (time to peak, TTP) and other hemodynamic parameters and perfusion image performance, it is a kind of functional imaging to evaluate the perfusion state of brain tissue
.
There is another perfusion time delay parameter, Delay Time (DT)
.
What is the diagnostic value of 2CTP? Cerebral perfusion imaging is mainly used to assess cerebral blood flow and brain metabolism.
The ischemic penumbra refers to brain tissue that can be rescued clinically
.
CTP has high accuracy in detecting acute infarction and ischemic penumbra, and has been widely used in clinical treatment decision-making for acute ischemic stroke
.
In actual clinical applications, there are post-processing software such as RAPID and MIStar.
They all define the area with Tmax greater than 6 seconds or DT> 3 seconds as penumbra (low perfusion area); areas with CBF <30% or more are regarded as core infarcts (Core)
.
Professor Cheng emphasized on the diagnostic value of CTP as follows: increase diagnostic confidence-is it a stroke-like episode? According to CTP, the risk stratification of light stroke is carried out; it is easier to identify abnormal perfusion than to identify occluded blood vessels; distal vascular occlusion is more sensitive than CTA; CTP can quantitatively assess collaterals; it can save ischemic penumbra vs necrotic tissue: CTA collateral assessment is more convenient; it increases the confidence in communication and decision-making with the patient’s family; avoids unnecessary endovascular treatment; broadens the treatment time window; predicts bleeding transformation
.
Application of 3CTP in Acute Lacunar Infarction In acute ischemic stroke, about 40% of patients have obvious hypoperfusion on CTP, but there are still 60% of patients who do not see obvious blood flow hypoperfusion, and a large part of it may be lacunar For patients with cerebral infarction, what is the value of CTP in acute cavitary infarction? Previous studies have mostly focused on how to identify acute luminal infarction on CTP.
Because CTP has a poor signal-to-noise ratio and thicker layer, if the lesion is small, it is likely to miss the lesion
.
How does CTP recognize cavitary infarction: ①CTP is better than CT plain scan + CTA; ②but it has low sensitivity and high specificity; ③MTT may be the most sensitive index
.
4 CTP in acute lamina infarction related research Since CTP is not sensitive to acute lamina infarction
.
Then: 1) Through the precise overlap of DWI and CTP at the same level, can the parameters of baseline CTP of infarct focus predict the prognosis of acute cavitary infarction? 2) Can intravenous alteplase (rt-PA) thrombolysis improve the perfusion of acute luminal infarction, thereby improving the prognosis of patients? For the above-mentioned scientific issues, the team of Professor Cheng Xin from Huashan Hospital conducted a retrospective study
.
A total of 959 patients with acute ischemic stroke who completed CTP in the emergency department from 2011.
11 to 2020.
12 in Huashan Hospital from 2011.
11 to 2020.
12 and had a DWI examination within 7 days were included, except for non-caval infarction, posterior circulation, severe stenosis of ipsilateral large vessels, and suspicious cardiogenic thrombosis.
Source patients, 71 patients with acute anterior circulation cavity infarction were eventually included in this study
.
The CTP original image and the DWI image of the same level are overlapped and calibrated to calculate the acute infarction, the contralateral mirror area of the acute infarction and the contralateral hemisphere perfusion parameters, including voxel-based CBF, CBV, MTT, DT
.
The relative perfusion parameter is defined as the ratio of the perfusion parameter of the acute infarction and the perfusion parameter of the contralateral mirror image area
.
The perfusion parameters and clinical outcomes as well as their interaction with intravenous thrombolysis were studied
.
At the same time, the perfusion parameters of patients undergoing perfusion CT before thrombolysis and those undergoing perfusion CT after thrombolysis were also compared
.
The mRS 0-1 in March was defined as a good prognosis
.
The results found: 1) A univariate comparison of good prognosis and poor prognosis after 3 months, age, gender, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline systolic blood pressure, baseline diastolic blood pressure, previous hypertension, and previous Diabetes, lesion size, white matter hyperintensity, no statistical significance
.
2) The multivariate stepwise regression model also included clinically relevant variables, and the contralateral hemisphere CBF was an independent predictor of a good prognosis in 3 months
.
3) After the baseline NIHSS is corrected, the higher CBF of the contralateral cerebral hemisphere is correlated with the smaller infarct volume
.
4) There is an interaction between rt-PA and CBF in the contralateral cerebral hemisphere for good prognosis in 3 months
.
The contralateral hemisphere CBF is in the range of 17.
6-24.
9 ml/mg/min.
Intravenous thrombolysis can improve the prognosis of patients with acute cavitary infarction.
If the contralateral hemisphere CBF is too low or too high, intravenous thrombolysis has no significant effect on the prognosis
.
5) There was no difference in baseline clinical and imaging data between patients who underwent CTP after thrombolysis and CTP before thrombolysis.
Compared with patients who underwent CTP before thrombolysis, more patients showed rCBF>1, P=0.
03, tPA can improve local blood perfusion in acute luminal infarction
.
As the time from onset to CTP imaging in patients with acute infarction increases, CBF and CBV gradually decrease, which proves that patients with acute infarction have collaterals
.
Of course, Professor Cheng also mentioned that this study is a single-center study, with a small sample, 10 people have no prognostic information, and there are certain limitations
.
Finally, the study concluded that: the contralateral cerebral hemisphere perfusion determines the prognosis of patients with acute luminal infarction in 3 months; the contralateral cerebral hemisphere perfusion determines the 3-month prognosis of patients with acute luminal infarction by tPA; the patients with CTP examination after tPA thrombolysis have more manifestations The local rCBF>1, P=0.
03.
tPA can improve the local blood perfusion of acute luminal infarction
.
This study shows that for patients with acute luminal infarction, the CBF of the contralateral hemisphere is an independent predictor of clinical prognosis, which again shows that cerebral small vessel disease is a disease of the whole brain, and the prognosis may be determined by the patient's own blood perfusion
.
The CBF of the contralateral hemisphere interacts with intravenous thrombolysis.
The CBF of the contralateral hemisphere is too low, even if intravenous thrombolysis cannot improve the prognosis, and the CBF of the contralateral hemisphere is too high, indicating that the patient's own collateral compensation is better and may not need veins.
Thrombolysis can also achieve a better prognosis
.
This study has been published (Lan Hong, Yifeng Ling, Ya Su, Lumeng Yan, Longting Lin, Mark Parsons, Xin Cheng, Qiang Dong.
Hemispheric cerebral blood flow predicts outcome in acute small subcortical infarcts.
J Cereb Blood Flow Metab.
2021 Aug 26 ;271678X211029884)
.
Expert Profile Cheng Xin Chief Physician Doctor of Medicine, Chief Physician of Neurology Department of Huashan Hospital Affiliated to Fudan University, Associate Professor, Postgraduate Tutor of Shanghai Youth Science and Technology Star, Young Top Talent Chinese Medical Association Neurology Branch Committee of Cerebrovascular Diseases, Chinese Stroke Society Deputy Chairman of Cerebral Small Vascular Disease Branch, Standing Committee of Cerebral Blood Flow and Metabolism Branch of Chinese Stroke Society, Standing Committee of Cerebrovascular Diseases Committee, National Health Commission, Cerebral Prevention Committee, Standing Committee of Cerebrovascular Diseases Committee, National Health Commission, Cerebral Defense Committee, Standing Committee, Youth Committee, Shanghai Medical Association, Science Popularization Branch, Youth Committee Vice-Chairman: The Youth Committee of the Neurology Specialist Branch of the Shanghai Medical Association Mainly focuses on the acute phase imaging and treatment of stroke, clinical and basic research on cerebral small vessel disease, and presides over the provincial and ministerial projects such as the National Natural Science Foundation of China, the Ministry of Education, and the Shanghai Science and Technology Commission6 As the backbone of the project, he participated in 2 key R&D programs of the Ministry of Science and Technology and was invited to publish reviews in Lancet Neurology.
As the first or corresponding author, he published more than 30 articles in domestic and foreign journals such as Annals of Neurology, Neurology, and edited 1 monograph.
4 consensus/standards of industry associations in this field
