Hemispheric Mean Transit Time of a Non-Diffusible Radioactive Tracer in Acute Stroke

1973 ◽  
Vol 9 (4) ◽  
pp. 197-201
Author(s):  
S. Lavy ◽  
D. Gurevitz ◽  
Y. Herishanu ◽  
E. Loewinger
Keyword(s):  
Acute Stroke ◽  
Transit Time ◽  
Mean Transit Time ◽  
Radioactive Tracer

Abstract 182: Early Perfusion Instability Profoundly Impacts Tissue Outcome In Acute Ischemic Stroke Patients

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Hongyu An ◽  
Andria L Ford ◽  
Yasheng Chen ◽  
Katie D Vo ◽  
William J Powers ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Stroke ◽  
Transit Time ◽  
Mean Transit Time ◽  
Tissue Perfusion ◽  
Tissue Viability ◽  
Stroke Patients ◽  
Dynamic Phase ◽  
Blue Line ◽  
Iv Tpa

Background: During the first hours after stroke onset, tissue perfusion in stroke patients may undergo a highly dynamic phase of instability. We examined the characteristics of this perfusion instability (improvement and deterioration) and its impact on tissue outcome. Methods: Mean transit time (MTT) and FLAIR maps were obtained in 45 acute stroke patients (mean NIHSS: 14; 73% received IV tPA) at 3.0 hrs (tp1), 6.4 hrs (tp2), and 1 month after onset. MTT prolongation (pMTT) was calculated as: MTT - (median MTT of the non-ischemic hemisphere). Tissue was classified into three subtypes: stable ( Methods: Mean transit time (MTT) and FLAIR maps were obtained in 45 acute stroke patients (mean NIHSS: 14; 73% received IV tPA) at 3.0 hrs (tp1), 6.4 hrs (tp2), and 1 month after onset. MTT prolongation (pMTT) was calculated as: MTT - (median MTT of the non-ischemic hemisphere). Tissue was classified into three subtypes: stable (|pMTT tp2-tp1| ≤ 2 sec), improving (pMTT tp2-tp1< -2 sec), and deteriorating (pMTT tp2-tp1>2 sec) perfusion. Percent volume was computed as: (the # of voxels of a tissue subtype/total # of voxels at a specific tp1 pMTT) for each subtype and their infarct probabilities (IP) were graphed (Fig A and B). To further evaluate perfusion change and the corresponding impact on IP, a 3D plot of IP (color axis, Fig. C) as a function of pMTT tp1 and tp2 was generated, pooling voxels from all patients. Results: Early perfusion instability (within 6.5 hrs) was observed in 70-85% of total volume at a specific tp1 pMTT (50-60% improving and 20-30% deteriorating perfusion) for a range of tp1 pMTT of 3-21 sec (Fig. A). Differences in IP were observed among the three tissue subtypes for pMTT 3-17 sec, while IPs were similar at small pMTT (< 3 sec) and large pMTT (>17 sec), (Fig. B). For pMTT of 3-17 sec, IP was highly dependent on perfusion changes at tp2 (Fig. C). For example, IP for voxels starting with pMTT of 12sec at tp1 ranged from 35-95% depending on perfusion change at tp2 (Fig. C, vertical blue line). Conclusions: Early perfusion changes profoundly impact tissue viability, especially with initial pMTT ranging from 3-17 sec (likely representing penumbral range). Acute stroke therapies may be effective not only by promoting reperfusion, but also by preventing deteriorating perfusion.

Paradoxically Decreased Mean Transit Time in Patients Presenting With Acute Stroke

2016 ◽  
Vol 40 (3) ◽  
pp. 409-412 ◽  
Author(s):  
Cédric Doucet ◽  
Federico Roncarolo ◽  
Donatella Tampieri ◽  
Maria del Pilar Cortes
Keyword(s):  
Acute Stroke ◽  
Transit Time ◽  
Mean Transit Time

scholarly journals Observer Agreement on Computed Tomography Perfusion Imaging in Acute Ischemic Stroke

Stroke ◽  
2019 ◽  
Vol 50 (11) ◽  
pp. 3108-3114 ◽  
Author(s):  
Salwa El-Tawil ◽  
Grant Mair ◽  
Xuya Huang ◽  
Eleni Sakka ◽  
Jeb Palmer ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Time Delay ◽  
Acute Stroke ◽  
Transit Time ◽  
Delay Time ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Observer Agreement ◽  
Intraobserver Agreement ◽  
Noncontrast Ct

Background and Purpose— Computed tomography (CT) perfusion (CTP) provides potentially valuable information to guide treatment decisions in acute stroke. Assessment of interobserver reliability of CTP has, however, been limited to small, mostly single center studies. We performed a large, internet-based study to assess observer reliability of CTP interpretation in acute stroke. Methods— We selected 24 cases from the IST-3 (Third International Stroke Trial), ATTEST (Alteplase Versus Tenecteplase for Thrombolysis After Ischaemic Stroke), and POSH (Post Stroke Hyperglycaemia) studies to illustrate various perfusion abnormalities. For each case, observers were presented with noncontrast CT, maps of cerebral blood volume, cerebral blood flow, mean transit time, delay time, and thresholded penumbra maps (dichotomized into penumbra and core), together with a short clinical vignette. Observers used a structured questionnaire to record presence of perfusion deficit, its extent compared with ischemic changes on noncontrast CT, and an Alberta Stroke Program Early CT Score for noncontrast CT and CTP. All images were viewed, and responses were collected online. We assessed observer agreement with Krippendorff-α. Intraobserver agreement was assessed by inviting observers who reviewed all scans for a repeat review of 6 scans. Results— Fifty seven observers contributed to the study, with 27 observers reviewing all 24 scans and 17 observers contributing repeat readings. Interobserver agreement was good to excellent for all CTP. Agreement was higher for perfusion maps compared with noncontrast CT and was higher for mean transit time, delay time, and penumbra map (Krippendorff-α =0.77, 0.79, and 0.81, respectively) compared with cerebral blood volume and cerebral blood flow (Krippendorff-α =0.69 and 0.62, respectively). Intraobserver agreement was fair to substantial in the majority of readers (Krippendorff-α ranged from 0.29 to 0.80). Conclusions— There are high levels of interobserver and intraobserver agreement for the interpretation of CTP in acute stroke, particularly of mean transit time, delay time, and penumbra maps.

Role of Mean Transit Time (MTT) Perfusion Map on the Aquilion ONE CT Scanner Using SVD+ Algorithm in Acute Stroke (P07.035)

Neurology ◽  
2012 ◽  
Vol 78 (Meeting Abstracts 1) ◽  
pp. P07.035-P07.035
Author(s):  
H. Dababneh ◽  
W. Guerrero ◽  
K. Wilson ◽  
J. Mocco ◽  
J. Bennett ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Transit Time ◽  
Mean Transit Time ◽  
Ct Scanner

Cerebral vascular mean transit time determined by PET and DSC-MRI

2005 ◽  
Vol 25 (1_suppl) ◽  
pp. S676-S676
Author(s):  
Masanobu Ibaraki ◽  
Hiroshi Ito ◽  
Eku Shimosegawa ◽  
Hideto Toyoshima ◽  
Keiichi Ishigame ◽  
...  
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Dsc Mri ◽  
Cerebral Vascular

Reproducibility of mean transit time for maximal myocardial flow assessment by videodensitometry

1990 ◽  
Vol 6 (2) ◽  
pp. 101-108 ◽  
Author(s):  
Nico H. J. Pijls ◽  
Gerard J. H. Uijen ◽  
Truus Pijnenburg ◽  
Karel van Leeuwen ◽  
Wim R. M. Aengevaeren ◽  
...  
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Myocardial Flow

scholarly journals Serial Quantitative Computed Tomography Perfusion in Aneurysmal Subarachnoid Hemorrhage

2016 ◽  
Vol 43 (3) ◽  
pp. 375-380 ◽  
Author(s):  
Cheemun Lum ◽  
Matthew J. Hogan ◽  
John Sinclair ◽  
Shane English ◽  
Howard Lesiuk ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Subarachnoid Hemorrhage ◽  
Middle Cerebral Artery ◽  
Transit Time ◽  
Cerebral Artery ◽  
Computed Tomography Angiography ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Mean Transit Time ◽  
Arterial Diameter ◽  
Computed Tomography Perfusion

AbstractPurpose: Computed tomography perfusion (CTP) has been performed to predict which patients with aneurysmal subarachnoid hemorrhage are at risk of developing delayed cerebral ischemia (DCI). Patients with severe arterial narrowing may have significant reduction in perfusion. However, many patients have less severe arterial narrowing. There is a paucity of literature evaluating perfusion changes which occur with mild to moderate narrowing. The purpose of our study was to investigate serial whole-brain CTP/computed tomography angiography in aneurysm-related subarachnoid hemorrhage (aSAH) patients with mild to moderate angiographic narrowing. Methods: We retrospectively studied 18 aSAH patients who had baseline and follow-up whole-brain CTP/computed tomography angiography. Thirty-one regions of interest/hemisphere at six levels were grouped by vascular territory. Arterial diameters were measured at the circle of Willis. The correlation between arterial diameter and change in CTP values, change in CTP in with and without DCI, and response to intra-arterial vasodilator therapy in DCI patients was evaluated. Results: There was correlation among the overall average cerebral blood flow (CBF; R=0.49, p<0.04), mean transit time (R=–0.48, p=0.04), and angiographic narrowing. In individual arterial territories, there was correlation between changes in CBF and arterial diameter in the middle cerebral artery (R=0.53, p=0.03), posterior cerebral artery (R=0.5, p=0.03), and anterior cerebral artery (R=0.54, p=0.02) territories. Prolonged mean transit time was correlated with arterial diameter narrowing in the middle cerebral artery territory (R=0.52, p=0.03). Patients with DCI tended to have serial worsening of CBF compared with those without DCI (p=0.055). Conclusions: Our preliminary study demonstrates there is a correlation between mild to moderate angiographic narrowing and serial changes in perfusion in patients with aSAH. Patients developing DCI tended to have progressively worsening CBF compared with those not developing DCI.

Probable range for whole kidney mean transit time values determined by reexamination of UK audit studies

2008 ◽  
Vol 29 (11) ◽  
pp. 1006-1014 ◽  
Author(s):  
Cyril C. Nimmon ◽  
John S. Fleming ◽  
Martin Šámal
Keyword(s):  
Transit Time ◽  
Mean Transit Time
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