Sep 25, 2014 the purpose of this investigation is to determine if ct perfusion ctp measurements at low doses ld 20 or 50 mas are similar to those obtained at regular doses rd 100 mas, with and without the addition of adaptive statistical iterative reconstruction asir. Understanding the postprocessing techniques, the value of each parameter and the perfusion changes seen in different conditions is essential for correct interpretation. Detailed anatomic and physiologic processes can be visualized including innovative modalities for. Neuroradiology differ ences in ct perfusion maps generated. This finding, in combination with high data variability, makes flat panel detector ct inappropriate for perfusion assessment in brain avms.
Ct perfusion ctp adds valuable information to the standard anatomical imaging techniques, consequently assisting diagnosis and guiding therapy in several neurological conditions. The purpose of this study is to compare ischemic core volumes estimated by intellispace portal isp and syngo. Arterial input and venous output timeattenuation curves were generated, with regions of interest manually drawn by the ct technologist performing the study, usually. Utility of perfusion ct and ct angiography on diagnosis and management m. Such applications procedure a quantitative measure of regional hemodynamics by demonstrating blood flow in each pixel of the cerebral parenchyma that is imaged. Of note, the delaysensitive software calculated cbv from mtt and cbf. Theoretic basis and technical implementations of ct. Ctp parameters that are commonly calculated by commercially available postprocessing software platforms include cbf, cbv. Commercial software packages for ct perfusion analysis are. Using 80 kvp versus 120 kvp in perfusion ct measurement of regional cerebral blood flow. Canon is on the left and ge healthcare is on the right.
This acquisition is summarized on ct perfusion maps that show different characteristics such as the timing of the bolus arrival and passage tmax and mtt, cerebral blood flow cbf, and cerebral blood volume cbv. Although ct perfusion is a promising tool to support treatment decisions for patients with acute ischemic stroke, it still lacks a standardized method for ctp analysis. After an unenhanced ct of the whole brain, and before a ct angiogram cta of the carotid and vertebral arteries and a postcontrast ct of the brain, sixteen 5mmthick sections are selected to include the level of the basal ganglia and centrum semiovale, where all three supratentorial vascular territories can be evaluated. Jun 01, 20 ct perfusion for confirmation of brain death ct perfusion for confirmation of brain death 20601 00. Comparison of perfusion ct software to predict the final.
Ct perfusion ctp is a functional imaging technique that provides. In this issue of the ajnr news digest, we highlight considerations regarding the use of ct perfusion ctp imaging for acute neurovascular assessment although the idea of measuring cerebral perfusion by tracking a contrast bolus with rapid sequence imaging has been around since the earliest days of ct, in the midlate 1970s, 1 it was not until two decades later that multidetector row ct. The next big advancement in cardiac imaging is likely to be computed tomography ct perfusion imaging. Computed tomography angiography cta and ct perfusion ctp of the brain are two imaging procedures which are reported to be of paramount importance in the evaluation of acute stroke apart from unenhanced ct for emergency situation 27. Early detection of acute stroke helps to reduce mortality rate since rapid treatment decision can be made by clinicians. Background and purpose ct perfusion ctp might support decision making in patients with acute ischemic stroke by providing perfusion maps of ischemic tissue. Center the table height, such that the external auditory meatus is located at the center of the gantry and the landmarked.
Preintervention fpdct perfusion showed restricted blood volume in the same territory fig 1b successful mechanical thrombectomy was performed fig 1 c pre and d post post intervention fpdct showed reversal of the blood volume perfusion deficit outside of the core infarct zone fig 1e. Perfusion is the passage of fluid through the lymphatic system or blood vessels to an organ or a tissue. Prediction of hemorrhage after successful recanalization in patients with acute ischemic stroke. In the median cbf as measured by 123 iimp spect of the impaired hemisphere, the moyamoya disease group value was 39. Ct perfusion ctp is a functional imaging technique that. The purpose of our study was to compare ctp and cta derived from the ctp data with the. The cbf and cbv are higher in gray matter than in white matter secondary to normal physiologic differences between these tissues 11. Ct perfusion imaging in acute stroke radiology key. Endovascular therapy for ischemic stroke with perfusion.
Cerebral ct angiography and ct perfusion in acute stroke. Theoretic basis and technical implementations of ct perfusion in. Quantitative cerebral blood flow measurement with dynamic perfusion ct using the vascularpixel elimination method. This is useful when assessing a patient for treatment. The software for postprocessing of ct perfusion data sets relies on selection of userdefined parameters, such as arterial and venous input functions and the cutoff values for unenhanced and enhanced images. Ct perfusion in ischemic stroke radiology reference. Postprocessing of ct perfusion imaging data after anonymization, the ct perfusion imaging data were postprocessed by one author k. To design a digital phantom data set for computed tomography ct perfusion and perfusionweighted imaging on the basis of the widely accepted tracer kinetic theory in which the true values of cerebral blood flow cbf, cerebral blood volume cbv, mean transit time mtt, and tracer arrival delay are known and to evaluate the accuracy and reliability of postprocessing programs using. Kudo et al demonstrated in 10 patient image datasets that brain perfusion maps resulting from ctp analysis by 5 different commercial software. This enables one commonly available modality to image both the detailed anatomy and function of the heart at the same time. Ge healthcare was used to calculate parametric maps of cbv and mtt by using baseline ct perfusion data, as described previously. After an unenhanced ct of the whole brain, and before a ctangiogram cta of the carotid and vertebral arteries and a postcontrast ct of the brain, sixteen 5mmthick sections are selected to include the level of the basal ganglia and centrum semiovale, where all three supratentorial vascular territories can be evaluated.
Optimal technique aids cerebral perfusion ct diagnostic. Both of these technologies have been around for a few years, but there have been an increasing amount of clinical data from studies showing the accuracy of the technology compared to nuclear imaging, the current stand of care for myocardial perfusion. These are mean transfer time mtt, cerebral blood flow cbf, cerebral blood volume cbv and time to peak ttp cbf cbvmtt. Cerebral perfusion computed tomography ct is a relatively new imaging technique that provides quantitative evaluation of cerebral perfusion by generating maps of cerebral blood flow, cerebral blood volume and mean transit time. Acute ischemic stroke is a disorder of blood flow to the brain.
Ct perfusion mean transit time maps optimally distinguish benign oligemia from true atrisk ischemic penumbra, but thresholds vary by postprocessing technique. Theoretic basis and technical implementations of ct perfusion in acute ischemic stroke, part 2. Jan 23, 2012 the next big advancement in cardiac imaging is likely to be computed tomography ct perfusion imaging. Advances in ct perfusion imaging imaging technology news. The units for ttp and mtt are seconds and 101seconds respectively. Flat panel detector ct perfusion depends on the time point chosen for data collection, which is triggered early in patients with avms.
The impact on medicine could reduce healthcare costs by eliminating some hospital stays, cutting the number of tests and speeding patient diagnosis. Comparison of three commonly used ct perfusion software. Both of these technologies have been around for a few years, but there have been an increasing amount of clinical data from studies showing the accuracy of the technology compared to nuclear imaging, the current stand of care for myocardial perfusion imaging, and. Nov 05, 2019 an overview perfusion mri gives access to information on the capillary microcirculation of tissue. Ct perfusion imaging, intracranial ct angiography was performed by using 60 ml of the same contrast agent. Preintervention fpd ct perfusion showed restricted blood volume in the same territory fig 1b successful mechanical thrombectomy was performed fig 1 c pre and d post post intervention fpd ct showed reversal of the blood volume perfusion deficit outside of the core infarct zone fig 1e. Exogenous tracers such as iced saline solution, iodinated radiographic contrast material, and radionuclides have been used 1, 2. Ct perfusion ctp is a functional imaging technique that provides important information about capillarylevel hemodynamics of the brain parenchyma and is a natural complement to the strengths of unenhanced ct and ct angiography in the evaluation of acute stroke, vasospasm, and other neurovascular disorders. Final infarct volumes for each mr imaging method and ctp software summation of infarct and penumbra due to it being a nonintervention case.
Kudo k, terae s, katoh c, oka m, shiga t, tamaki n, et al quantitative cerebral blood flow measurement with dynamic perfusion ct using the vascularpixel. Two examples of ct myocardial perfusion ctp imaging assessment software. Measurement of tissue perfusion depends on the ability to serially measure concentration of a tracer agent in a target organ of interest. Pct scans at our institution are obtained using a 64slice ct scanner. Reproducibility of postprocessing of quantitative ct.
The purpose of this study was to assess the variability of the area of infarct core and penumbra as presented in summary maps produced by 2 different software packages. Image coregistration software to correct for patient motion and careful choice of regions. Ctp is an approximately 1min dynamic acquisition of a contrast bolus passing through the brain. Correlation of early dynamic ct perfusion imaging with wholebrain mr diffusion and perfusion imaging in acute hemispheric stroke.
D, mtt map shows a corresponding prolongation within this same region arrows. For pronouncing brain death, unlike ctp, the 2phase cta gives no functional information and is limited by inadvertent delay of the second acquisition, which may give falsenegative results. The ultimate goal of perfusion mri is to measure or assess the blood flow irrigating the explored organ, expressed in milliliters per 100 gram. Differences in ct perfusion summary maps for patients with. How radiologists add value on february 11th at 3 p. Cerebral perfusion computed tomography ct is a relatively new imaging technique that provides quantitative evaluation of cerebral perfusion by generating maps of cerebral blood flow, cerebral blood volume. Ct perfusion ctp expands the role of ct in the evaluation of acute stroke by providing physiologic insights into cerebral hemodynamics, and in so doing complements the strengths of ct angiography cta by determining the consequences of vessel occlusions and stenoses fig. The term perfusion scanning encompasses a wide range of medical imaging modalities. Evaluation of ct perfusion in the setting of cerebral. This protocol may include an optional, non contrast enhanced head scan andor an optoi na lhead ct angoi gram.
To account for regional differences in perfusion values across brain. To evaluate the utility of perfusion ct pct combined with ct angiography cta for the. In recent years, perfusionct pct imaging has emerged as a useful tool to evaluate patients with suspected stroke 1, 2. Ct perfusion in ischemic stroke has become established in most centers with stroke services as an important adjunct, along with ct angiography cta, to conventional unenhanced ct brain imaging it enables differentiation of salvageable ischemic brain tissue the penumbra from the irrevocably damaged infarcted brain the infarct core. There was a significant difference between these values p dec 27, 2012 using perfusion analysis software several parameters are calculated.
The purpose of our study was to compare ctp and cta derived from the ctp data. A singlecenter, prospective study was performed in patients with acute ischemic stroke n 37. The practice of perfusion scanning, is the process by which this perfusion can be observed, recorded and quantified. Currently, the reliability of ctp is hampered by varying results between different postprocessing software packages. More recently, with the advent of mr imaging, exogenous tracer agents, such as paramagnetic contrast material, and endogenous. The neuroradiology section of diagnostic radiology offers a full range of state of the art computed tomography ct and magnetic resonance imaging mri services for the neuroaxis including the brain, spinal cord, skull, orbits, sinuses, temporal bone, and neck of the adult and pediatric patient. Simultaneous measurement of regional cerebral blood flow by perfusion ct and stable xenon ct. The dicom images of bayesianprocessed ctp maps were exported into this software to. Jan 23, 2012 two examples of ct myocardial perfusion ctp imaging assessment software. These parameters are used in a mathematic model for generation of quantitative cbf, cbv, and mtt data for interpretation. Evaluation of ct perfusion in the setting of cerebral ischemia ajnr. We aimed to assess the performance of an automated aspects software against the assessment of a neuroradiologist in a comparative analysis with concurrent ctpbased cbv aspects. The purpose of this investigation is to determine if ct perfusion ctp measurements at low doses ld 20 or 50 mas are similar to those obtained at regular doses rd 100 mas, with and without the addition of adaptive statistical iterative reconstruction asir. Differences in ct perfusion summary maps for patients with acute.
Alberta stroke program early ct scoring of ct perfusion in early stroke visualization and assessment. In addition, ct perfusion imaging, which was processed with the use of fully automated software rapid, noncommercial research version, stanford university, 12, was used to identify potentially. Hamann, jan baranczyk, bernhard rosengarten, erich klotz, martin wiesmann, ulrich missler, gernot schultealtedorneburg, and hartmuth j. Comparison of cerebral blood flow between perfusion computed. What is the role of ct perfusion maps in stroke imaging. Feasibility of flat panel detector ct in perfusion. Ct perfusion software that interfaces with helical scanners can meet the clinical needs for evaluation of acute and subacute stoke. As stated in the acute stroke imaging research roadmap. There was a significant difference between these values p computed tomography. Improved risk stratification using dualenergy ct parenchymal iodine concentration ratio relative to the superior sagittal sinus.
Ct perfusion for confirmation of brain death deepdyve. Accuracy and reliability assessment of ct and mr perfusion. Ct perfusion ctp is a functional imaging technique that provides important information about capillarylevel hemodynamics of the brain parenchyma and is a natural complement to the strengths of. Assessment of a bayesian vitrea ct perfusion analysis to. Differences in ct perfusion maps generated by different. The main quantitative parameters measured are blood volumes and temporal data transit time, time to contrast peak. A 64yearold man presenting with headache and acute aphasia.
B, ct perfusion cbf map shows a region of decreased perfusion within the posterior segment of the left mca territory arrows. Cerebral perfusion ct is less invasive than ct angiography and is fast and available for most standard spiral ct scanners equipped with the appropriate software. Ct with ct angiography and ct perfusion before management decisions article pdf available in american journal of neuroradiology 335. Ct perfusion for confirmation of brain death ct perfusion for confirmation of brain death 20601 00. Pct has been advocated to detect and characterize the ischemic penumbra 3, 4, but also to assess bloodbrain barrier permeability in an effort to predict the risk of hemorrhagic conversion after stroke 57. Automated aspects has the potential of reducing interobserver variability in the determination of early ischemic changes. An overview perfusion mri gives access to information on the capillary microcirculation of tissue. The preoperative cbf as measured by 123 iimp spect and ct perfusion is shown in fig. Automated versus manual postprocessing of perfusionct.
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