Whole brain CT perfusion on a 320-slice CT scanner

We aimed to investigate the overall prevalence and possible factors influencing the occurrence of crossed cerebellar diaschisis after acute middle cerebral artery infarction using whole-brain CT perfusion. A total of 156 patients with unilateral hypoperfusion of the middle cerebral artery territory formed the study cohort; 352 patients without hypoperfusion served as controls. We performed blinded reading of different perfusion maps for the presence of crossed cerebellar diaschisis and determined the relative supratentorial and cerebellar perfusion reduction. Moreover, imaging patterns (location and volume of hypoperfusion) and clinical factors (age, sex, time from symptom onset) resulting in crossed cerebellar diaschisis were analysed. Crossed cerebellar diaschisis was detected in 35.3% of the patients with middle cerebral artery infarction. Crossed cerebellar diaschisis was significantly associated with hypoperfusion involving the left hemisphere, the frontal lobe and the thalamus. The degree of the relative supratentorial perfusion reduction was significantly more pronounced in crossed cerebellar diaschisis-positive patients but did not correlate with the relative cerebellar perfusion reduction. Our data suggest that (i) crossed cerebellar diaschisis is a common feature after middle cerebral artery infarction which can robustly be detected using whole-brain CT perfusion, (ii) its occurrence is influenced by location and degree of the supratentorial perfusion reduction rather than infarct volume (iii) other clinical factors (age, sex and time from symptom onset) did not affect the occurrence of crossed cerebellar diaschisis.

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Abstract WP45: Comparison of Automated Whole Brain CT Perfusion Analysis with Perfusion-Diffusion MRI in Ischemic Stroke

Stroke ◽

10.1161/str.44.suppl_1.awp45 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Bruce C Campbell ◽

Søren Christensen ◽

Nawaf Yassi ◽

Gagan Sharma ◽

Andrew Bivard ◽

...

Keyword(s):

Ischemic Stroke ◽

Diffusion Mri ◽

Ct Perfusion ◽

Diffusion Imaging ◽

Residue Function ◽

Accurate Estimate ◽

Mr Perfusion ◽

Infarct Core ◽

Whole Brain ◽

Brain Ct

Background and purpose: CT perfusion (CTP) provides rapid and accessible imaging of ischemic stroke pathophysiology. Studies with limited brain coverage CTP have suggested that relative cerebral blood flow (relCBF) is the optimal CTP parameter to define irreversible infarction. We analyzed patients with whole brain CT perfusion and contemporaneous MR perfusion-diffusion imaging to confirm the optimal CTP parameter for infarct core and compare mismatch classification between MR and CT. Methods: Acute ischemic stroke patients <6hr after onset had whole brain CTP (320slice) closely followed by perfusion-diffusion MRI. Maps of CBF, CBV and time-to-peak of the deconvolved tissue residue function (Tmax) were generated by RAPID automated perfusion analysis software (Stanford University) using delay insensitive deconvolution. The optimal CTP map to identify infarct core was selected by maximizing the average Dice co-efficient across the same threshold range for all patients using co-registered diffusion lesion (manually outlined to its maximal visual extent) as reference region. Mismatch classification agreement between CT and MRI was then assessed using 2 definitions: mismatch ratio a) >1.2 or b) >1.8, absolute mismatch a) >10mL or b) >15mL, infarct core<70mL. Results: In 28 patients imaged <6hr from stroke onset (median age 69, median onset to CT 180min, median CT to MR 69min), relCBF provided the most accurate estimate for infarct core, significantly better than absolute or relative CBV (both p<0.001). Using relCBF to generate acute CTP infarct core volumes, the median magnitude of volume difference versus diffusion MR was 6.9mL, interquartile range 1.6-27.4mL. CTP mismatch between relCBF core and Tmax>6sec perfusion lesion was assessed in 25 patients (3/28 had no MR perfusion). CTP and MR perfusion-diffusion mismatch classification agreed in 23/25 (92%) patients (kappa 0.84) using either definition. Conclusions: This study using whole brain CTP confirms the greater accuracy of CBF over CBV for estimation of the infarct core. The >90% agreement in mismatch classification between CTP and MRI supports the concept that both modalities can identify similar patient populations for clinical trials of reperfusion therapies.

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Whole-brain CT perfusion: reliability and reproducibility of volumetric perfusion deficit assessment in patients with acute ischemic stroke

Neuroradiology ◽

10.1007/s00234-013-1179-0 ◽

2013 ◽

Vol 55 (7) ◽

pp. 827-835 ◽

Cited By ~ 49

Author(s):

Kolja M. Thierfelder ◽

Wieland H. Sommer ◽

Alena B. Baumann ◽

Ernst Klotz ◽

Felix G. Meinel ◽

...

Keyword(s):

Ischemic Stroke ◽

Acute Ischemic Stroke ◽

Ct Perfusion ◽

Perfusion Deficit ◽

Whole Brain ◽

Brain Ct

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Preliminary study of whole-brain CT perfusion imaging in patients with intracranial tumours adjacent to large blood vessels

Clinical Radiology ◽

10.1016/j.crad.2013.08.010 ◽

2014 ◽

Vol 69 (1) ◽

pp. e25-e32 ◽

Cited By ~ 9

Author(s):

T. Chen ◽

D. Guo ◽

Z. Fang ◽

W. Zhong ◽

J. Zhao ◽

...

Keyword(s):

Blood Vessels ◽

Perfusion Imaging ◽

Ct Perfusion ◽

Whole Brain ◽

Intracranial Tumours ◽

Brain Ct ◽

Ct Perfusion Imaging ◽

Preliminary Study

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Total Bolus Extraction Method Improves Arterial Image Quality in Dynamic CTAs Derived from Whole-Brain CTP Data

BioMed Research International ◽

10.1155/2014/603173 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6

Author(s):

Elyas Ghariq ◽

Adriënne M. Mendrik ◽

Peter W. A. Willems ◽

Raoul M. S. Joemai ◽

Eidrees Ghariq ◽

...

Keyword(s):

Image Quality ◽

Ct Perfusion ◽

Ct Scanner ◽

Whole Brain ◽

Acute Cerebral Ischemia ◽

Dynamic Ct Angiography ◽

Information Dynamic ◽

Hemodynamic Information ◽

Ophthalmic Arteries

Background and Purposes. The 320-detector row CT scanner enables visualization of whole-brain hemodynamic information (dynamic CT angiography (CTA) derived from CT perfusion scans). However, arterial image quality in dynamic CTA (dCTA) is inferior to arterial image quality in standard CTA. This study evaluates whether the arterial image quality can be improved by using a total bolus extraction (ToBE) method.Materials and Methods. DCTAs of 15 patients, who presented with signs of acute cerebral ischemia, were derived from 320-slice CT perfusion scans using both the standard subtraction method and the proposed ToBE method. Two neurointerventionalists blinded to the scan type scored the arterial image quality on a 5-point scale in the 4D dCTAs in consensus. Arteries were divided into four categories: (I) large extradural, (II) intradural (large, medium, and small), (III) communicating arteries, and (IV) cerebellar and ophthalmic arteries.Results. Quality of extradural and intradural arteries was significantly higher in the ToBE dCTAs than in the standard dCTAs (extraduralP=0.001, large intraduralP<0.001, medium intraduralP<0.001, and small intraduralP<0.001).Conclusion. The 4D dCTAs derived with the total bolus extraction (ToBE) method provide hemodynamic information combined with improved arterial image quality as compared to standard 4D dCTAs.

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