Abstract WP42: CT Perfusion in Acute Stroke: Substantial Value Beyond Penumbra

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sarah W Meng ◽  
Michael Hewitt ◽  
Xiang Liu

Purpose: The role of CT Perfusion (CTP) in evaluation of acute stroke remains controversial, especially in determining ischemic penumbra and core infarct. Thus, our institution suspended CTP as part of the acute stroke imaging protocol, and now includes a non-contrast head CT (NCCT) and CT angiography (CTA) of the head and neck. We performed a retrospective review of cases using NCCT, CTA and CTP (CT-CTP) and cases using NCCT and CTA (CT-CTA protocol) at our institution from 2009 to 2011, to assess what, if any, substantial benefit CTP provides in the management of acute stroke. Methods: A total of 758 cases were reviewed, including 375 cases in the CT-CTP protocol and 383 cases in the CT-CTA protocol. Acute infarcts limited to the area covered by CTP were reviewed to compare the diagnostic sensitivity of the two protocols. Followup DWI or NCCT was used as the reference standard for final infarct size. Infarct volume was measured by freehand region of interest measurement. A subset group with final infarct volume > 30ml was also reviewed to explore the detection sensitivity of vascular thrombosis. Results: CTP deficits were reported in all 71 cases with a final infarct volume of 2.8 ml and above. Conversely, in the same category, 23 of 96 (24%) cases were reported as negative with CT-CTA protocol. Of the 10 cases with final infarct volume > 30ml and reported as negative in the CT- CTA protocol, 7of 10 had 2nd or 3rd order vascular thromboses, including 6 cases with infarct volume > 50ml. Only 2 of 45 thromboses were missed in the same category with CT-CTP protocol. Vascular thrombosis was missed in 1 of 10 cases with final infarct volume > 30ml in the CT-CTP protocol where NCCT was reported as negative but had positive CTP deficits. Conclusions: There is a substantially greater detection rate of 2nd and 3rd order vascular thrombosis when CTP is performed, including cases when NCCT is deemed negative. We speculate that a negative NCCT may provide false assurance, but that CTP deficits will guide attention to the area of interest, ultimately increasing detection of vascular occlusion and potentially influencing treatment options in the setting of acute stroke. Additionally, CTP significantly increases the diagnostic sensitivity of acute stroke compared to a combination of NCCT and CTA alone.

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Sarah W Meng ◽  
Xiang Liu ◽  
Michael Hewitt

Purpose: In a previous study, we found higher detection rate of 2nd and 3rd order vascular thrombosis when CT Perfusion (CTP) was performed as compared to non-contrast CT (NCCT) and CT angiography (CTA) alone. Additionally, a significant number of patients with acute infarct were reported as negative without CTP. In this study, we sought to determine whether missed imaging diagnosis without CTP might affect clinical decision making. Methods: A total of 758 cases were included in our previous study, with CTP deficits reported in all 71 cases with final infarct volume of 2.8 ml or above. Conversely, 23 of 96 (24%) cases without CTP were reported as negative. In the group without CTP, 7 of 10 patients who had 2nd or 3rd order vascular thromboses with a final infarct > 30cc were reported negative, whereas only 1 of 10 cases were missed in patients who had CTP but a negative NCCT. The treatment decisions at the time of stroke were reviewed for these patients. Results: In 10 cases with final infarct volume > 30ml reported negative without CTP, zero received TPA or thrombectomy. Conversely, in the same category, 5 of 10 cases with positive CTP received TPA (p = 0.041). There was also a higher rate of TPA or thrombectomy treatment in patients with a positive imaging diagnosis, both with CTP (13 of 71, 18.3%) and without CTP (28 of 73, 38.4%), as compared to the group reported negative without CTP (3 of 23, 13%, p = 0.059). Fewer cases in the CTP group received treatment as compared to cases reported positive without CTP. A possible reason is that the cases with CTP were from an earlier phase of our acute stroke program, when treatment tended to be more conservative. Conclusions: Our study finds discrepancies in decision making for TPA and thrombectomy in stroke cases with positive versus negative imaging diagnosis. The cases reported negative were less likely to receive treatment, including those with relatively large final infarct size (>30ml). We speculate that a negative imaging diagnosis may create doubt for clinical diagnosis in some cases. Adding CTP in the acute stroke imaging protocol will increase imaging diagnostic accuracy and exclude stroke mimics, therefore providing valuable information for treatment.


2018 ◽  
Vol 19 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Stevan Christopher Wing ◽  
Hugh S Markus

CT perfusion images can be rapidly obtained on all modern CT scanners and easily incorporated into an acute stroke imaging protocol. Here we discuss the technique of CT perfusion imaging, how to interpret the data and how it can contribute to the diagnosis of acute stroke and selection of patients for treatment. Many patients with acute stroke are excluded from reperfusion therapy if the onset time is not known or if they present outside of traditional treatment time windows. There is a growing body of evidence supporting the use of perfusion imaging in these patients to identify patterns of brain perfusion that are favourable for recanalisation therapy.


Author(s):  
Dylan Blacquiere ◽  
Miguel Bussière ◽  
Cheemun Lum ◽  
Dar Dowlatshahi

Avascularity on CT angiography source images (CTASI) may better predict final infarct volume in acute stroke as compared to early ischemic changes on non-contract CT. These CTASI findings may represent infarct core and help determine the extent of salvageable tissue. However, the extent of avascularity on CTASI may overestimate infarct volume if transit of contrast is prolonged due to proximal artery occlusion. We present a case where CT-perfusion (CTP) and time-resolved CT-angiography (CTA) identified salvageable tissue thought to be infarcted on CTASI.


2021 ◽  
pp. neurintsurg-2021-018241
Author(s):  
Marta Olive-Gadea ◽  
Manuel Requena ◽  
Facundo Diaz ◽  
Sandra Boned ◽  
Alvaro Garcia-Tornel ◽  
...  

BackgroundIn patients with stroke, current guidelines recommend non-invasive vascular imaging to identify intracranial vessel occlusions (VO) that may benefit from endovascular treatment (EVT). However, VO can be missed in CT angiography (CTA) readings. We aim to evaluate the impact of consistently including CT perfusion (CTP) in admission stroke imaging protocols.MethodsFrom April to October 2020 all patients admitted with a suspected acute ischemic stroke underwent urgent non-contrast CT, CTA and CTP and were treated accordingly. Hypoperfusion areas defined by time-to-maximum of the tissue residue function (Tmax) >6 s, congruent with the clinical symptoms and a vascular territory, were considered VO (CTP-VO). In addition, two experienced neuroradiologists blinded to CTP but not to clinical symptoms retrospectively evaluated non-contrast CT and CTA to identify intracranial VO (CTA-VO).ResultsOf the 338 patients included in the analysis, 157 (46.5%) presented with CTP-VO (median Tmax >6s: 73 (29–127) mL). CTA-VO was identified in 83 (24.5%) of the cases. Overall CTA-VO sensitivity for the detection of CTP-VO was 50.3% and specificity was 97.8%. Higher hypoperfusion volume was associated with increased CTA-VO detection (OR 1.03; 95% CI 1.02 to 1.04). EVT was performed in 103 patients (30.5%; Tmax >6s: 102 (63–160) mL), representing 65.6% of all CTP-VO. Overall CTA-VO sensitivity for the detection of EVT-VO was 69.9% and specificity was 95.3%. Among patients who received EVT, the rate of false negative CTA-VO was 30.1% (Tmax >6s: 69 (46–99.5) mL).ConclusionSystematically including CTP in acute stroke admission imaging protocols may increase the diagnosis of VO and rate of EVT.


2013 ◽  
Vol 84 (11) ◽  
pp. e2.196-e2 ◽  
Author(s):  
Gavin Langlands ◽  
Jai Shankar ◽  
Wendy Simpkin ◽  
Christine Christian ◽  
Stephen Phillips

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Marina Padroni ◽  
Pilar Coscojuela ◽  
Sandra Boned ◽  
Marc Ribó ◽  
Jordi Cabero ◽  
...  

Introduction: The best technique for selecting acute stroke patients for reperfusion therapies is not defined yet. ASPECTS is a useful score for assessing the extent of early ischemic signs in the anterior circulation on non-contrast CT (CT). Cerebral blood volume (CBV) on CT perfusion (CTP) defines the core lesion assumed to be irreversibly damaged. Whether CBV provides additional information over CT in the initial ASPECTS assessment is unknown. We aim to explore the advantages of CBV_ASPECTS over CT_ASPECTS in the prediction of final infarct volume. Methods: Consecutive patients with middle cerebral or internal carotid artery occlusion who underwent endovascular reperfusion treatment according to initial CT_ASPECTS≥7 were studied. CBV_ASPECTS was assessed blindly later-on. Recanalization was defined as TICI2b3. Final infarct volumes were measured on follow-up imaging. We defined an irrelevant ASPECTS difference (IAD) as: CT_ASPECTS - CBV_ASPECTS≤1. Results: Sixty-five patients, mean age 67±14, median NIHSS:16(10-20) were studied. Recanalization rate was: 78.5%. Median CT_ASPECTS was 9(8-10), and CBV_ASPECTS 8(8-10). Mean time from symptom onset to CT was 219±143 min. 50 patients (76.9%) showed an IAD. The ASPECTS difference was inversely correlated to the time from symptom onset to CT (r:-0.36, p<0.01). A ROC curve defined 120 minutes as the best cut-off time point after which the ASPECTS difference becomes irrelevant. The rate of IAD was significantly higher after 120 minutes (89.5% Vs 37.5; p<0.01). CBV_ASPECTS but not CT_ASPECTS correlated to the final infarct (r:-0.33, p<0.01). However, if CT was done >2 hours after symptom onset, then CT_ASPECTS was correlated to final infarct (r:-0.39, p=0.01). No other variables were associated with CT-CBV_ASPECTS difference. Conclusions: In acute stroke patient CBV_ASPECTS correlates with final infarct volume. However, when CT is performed after 120 minutes from symptoms onset CBV_ASPECTS does not add relevant information to CT_ASPECTS.


2011 ◽  
Vol 30 (6) ◽  
pp. E4 ◽  
Author(s):  
Peter T. Kan ◽  
Kenneth V. Snyder ◽  
Parham Yashar ◽  
Adnan H. Siddiqui ◽  
L. Nelson Hopkins ◽  
...  

Computed tomography perfusion scanning generates physiological flow parameters of the brain parenchyma, allowing differentiation of ischemic penumbra and core infarct. Perfusion maps, along with the National Institutes of Health Stroke Scale score, are used as the bases for endovascular stroke intervention at the authors' institute, regardless of the time interval from stroke onset. With case examples, the authors illustrate their perfusion-based imaging guidelines in patient selection for endovascular treatment in the setting of acute stroke.


Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Tareq Kass-Hout ◽  
Maxim Mokin ◽  
Omar Kass-Hout ◽  
Emad Nourollahzadeh ◽  
David Wack ◽  
...  

Objective: To use the Computed Tomography Perfusion (CTP) parameters at the time of hospital admission, including Cerebral Blood Volume (CBV) and Permeability Surface area product (PS), to identify patients with higher risk to develop hemorrhagic transformation in the setting of acute stroke therapy with intravenous thrombolysis. Methods: Retrospective study that compared admission CTP variables between patients with Hemorrhagic Transformation (HT) acute stroke and those with no hemorrhagic transformation. Both groups received standard of care intravenous thrombolysis with tPA. Twenty patients presented to our stroke center between the years 2007 - 2011 within 3 hours after stroke symptoms onset. All patients underwent two-phase 320 slice CTP which creates CBV and PS measurements. Patients were divided into two groups according to whether or not they had HT on a follow up CT head without contrast, done within 36 hours of the thrombolysis therapy. Clinical, demographic and CTP variables were compared between the HT and non-HT groups using logistic regression analyses. Results: HT developed in 8 (40%) patients. Patients with HT had lower ASPECT score ( P =.03), higher NIHSS on admission ( P= .01) and worse outcome ( P= .04) compared to patients who did not develop HT. Baseline blood flow defects were comparable between the two groups. The mean PS for the HT group was 0.53 mL/min/100g brain tissue, which was significantly higher than that for the non-HT group of 0.04 mL/min/100g brain tissue ( P <.0001). The mean area under the curve was 0.92 (95% CI). The PS threshold of 0.26 mL/min/100g brain tissue had a sensitivity of 80% and a specificity of 92% for detecting patients with high risk of hemorrhagic transformation after intravenous thrombolysis. Conclusions: Admission CTP measurements might be useful to predict patients who are at higher risk to develop hemorrhagic transformation after acute ischemic stroke therapy.


Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Nili E Steiner ◽  
Nicole Wolber ◽  
Betty Robertson ◽  
Paula Rosenfield ◽  
Laurie Paletz

Background: Brain ischemia kills 2 million nerve cells per minute. As time elapses, the odds of favorable outcome become less likely. By providing treatment rapidly, patient outcome is markedly improved. We recognized an opportunity for improvement by shortening our door-to-needle time. The door-to-needle time is defined by the time the patient arrives in the emergency department to the time the patient receives intravenous tissue plasminogen activator (IV t-PA). Methods: We evaluated the system in place to look at opportunities for improvement. We met monthly to assess every acute stroke patient case, particularly to evaluate delays in acute stroke treatment. We analyzed the results of all the acute stroke patient cases from January 2008 to January 2012. We implemented the following interventions: staff education, reducing unnecessary CT angiogram and CT perfusion studies on patients, RN telephone triage for acute stroke patients. pre-hospital activation of the stroke team for patients exhibiting acute stroke symptoms, ED pharmacist at bedside upon patient arrival with t-PA, and placing patients on portable monitors immediately upon ED arrival. Conclusion: The average door-to-needle time from January 2008 to October 2011 was 1 hour and 32 minutes. After implementing the changes above, from November 2011 to January 2012, our average door-to-needle time was 38 minutes to 54 minutes, which is within the target of less than 60 minutes. By implementing these changes, we have successfully and safely reduced and improved our door-to-needle time. Monthly quality improvement meetings are on-going to assess continuing quality improvement.


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