scholarly journals Noninvasive Estimation of the Arterial Input Function in Positron Emission Tomography Imaging of Cerebral Blood Flow

2012 ◽  
Vol 33 (1) ◽  
pp. 115-121 ◽  
Author(s):  
Yi Su ◽  
Ana M Arbelaez ◽  
Tammie LS Benzinger ◽  
Abraham Z Snyder ◽  
Andrei G Vlassenko ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid ◽  
Arterial Input Function ◽  
Input Function ◽  
Emission Tomography ◽  
Positron Emission ◽  
Arterial Sampling

Positron emission tomography (PET) with 15O-labeled water can provide reliable measurement of cerebral blood flow (CBF). Quantification of CBF requires knowledge of the arterial input function (AIF), which is usually provided by arterial blood sampling. However, arterial sampling is invasive. Moreover, the blood generally is sampled at the wrist, which does not perfectly represent the AIF of the brain, because of the effects of delay and dispersion. We developed and validated a new noninvasive method to obtain the AIF directly by PET imaging of the internal carotid artery in a region of interest (ROI) defined by coregistered high-resolution magnetic resonance angiography. An ROI centered at the petrous portion of the internal carotid artery was defined, and the AIF was estimated simultaneously with whole brain blood flow. The image-derived AIF (IDAIF) method was validated against conventional arterial sampling. The IDAIF generated highly reproducible CBF estimations, generally in good agreement with the conventional technique.

scholarly journals Cerebral Blood Flow and Metabolism Measurement Using Positron Emission Tomography before and during Internal Carotid Artery Test Occlusions: Feasibility of Rapid Quantitative Measurement of CBF and OEF/CMRO2

2012 ◽  
Vol 18 (3) ◽  
pp. 264-274 ◽  
Author(s):  
N. Kawai ◽  
M. Kawanishi ◽  
A. Shindou ◽  
N. Kudomi ◽  
Y. Yamamoto ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
False Negative ◽  
Photon Emission ◽  
Emission Tomography ◽  
Positron Emission

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study is a sensitive test for predicting the outcome of permanent ICA occlusion. However, false negative results sometimes occur using single photon emission tomography (SPECT). We have recently developed a rapid positron emission tomography (PET) protocol that measures not only the CBF but also the cerebral oxygen metabolism before and during BTO in succession. We measured acute changes in regional CBF and OEF/CMRO2 before and during BTO in three cases with large or giant cerebral aneurysms using the rapid PET protocol. Although no patients showed ischemic symptoms during BTO, PET studies exhibited mildly to moderately decreased CBF (9∼34%) compared to the values obtained before BTO in all cases. The average OEF during BTO was significantly increased (21% and 43%) than that of before BTO in two cases. The two cases were considered to be non-tolerant for permanent ICA occlusion and treated without ICA sacrifice. Measurement of the CBF and OEF/CMRO2 using a rapid PET protocol before and during BTO is feasible and can be used for accurate assessment of tolerance prediction in ICA occlusion.

[O-15]H2O Positron Emission Tomography Determination of Cerebral Blood Flow Reserve after Intravenous Acetazolamide during Balloon Test Occlusion of the Internal Carotid Artery

1998 ◽  
Vol 4 (1) ◽  
pp. 57-62 ◽  
Author(s):  
K.J. Murphy ◽  
J.P. Deveikis ◽  
J.A. Brunberg ◽  
D.A. Jamadar ◽  
K.A. Frey
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid ◽  
Balloon Occlusion ◽  
Emission Tomography ◽  
Balloon Test Occlusion ◽  
Positron Emission ◽  
O 15

The purpose of this paper was to evaluate the effects of acetazolamide on cerebral blood flow (CBF) measured by [O-15] H2O positron emission tomography (PET) during balloon test occlusion (BTO) of the internal carotid artery (ICA). [O-15] H2O PET cerebral blood flow studies were completed in 20 patients undergoing BTO. CBF determinations were obtained without carotid occlusion as a baseline, following balloon occlusion, and as a third scan with balloon occlusion after an intravenous acetazolamide bolus. The balloon was left deflated between scans, and was only inflated immediately before and during the 90 second period of time needed for CBF determination. Significance was determined at the P<0.05 level. Two of twenty studies were technical failures. Prior to acetazolamide there was a significant decrease in CBF (P<0.0007) ipsilateral to the occlusion. After acetazolamide administration there was no statistically significant change in flow on the occluded side (P<0.3047); however, there was a significant increase in cerebral blood flow (P<0.0002) on the non-occluded side. In this patient population, there was no acetazolamide-induced CBF decompensation (steal) phenomenon or haemodynamically significant risk in CBF ipsilateral to the occlusion.

scholarly journals Positron Emission Tomography/Magnetic Resonance Hybrid Scanner Imaging of Cerebral Blood Flow Using 15O-Water Positron Emission Tomography and Arterial Spin Labeling Magnetic Resonance Imaging in Newborn Piglets

2015 ◽  
Vol 35 (11) ◽  
pp. 1703-1710 ◽  
Author(s):  
Julie B Andersen ◽  
William S Henning ◽  
Ulrich Lindberg ◽  
Claes N Ladefoged ◽  
Liselotte Højgaard ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Arterial Spin Labeling ◽  
Input Function ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Newborn Piglets ◽  
Positron Emission

Abnormality in cerebral blood flow (CBF) distribution can lead to hypoxic–ischemic cerebral damage in newborn infants. The aim of the study was to investigate minimally invasive approaches to measure CBF by comparing simultaneous 15O-water positron emission tomography (PET) and single TI pulsed arterial spin labeling (ASL) magnetic resonance imaging (MR) on a hybrid PET/MR in seven newborn piglets. Positron emission tomography was performed with IV injections of 20 MBq and 100 MBq 15O-water to confirm CBF reliability at low activity. Cerebral blood flow was quantified using a one-tissue-compartment-model using two input functions: an arterial input function (AIF) or an image-derived input function (IDIF). The mean global CBF (95% CI) PET-AIF, PET-IDIF, and ASL at baseline were 27 (23; 32), 34 (31; 37), and 27 (22; 32) mL/100 g per minute, respectively. At acetazolamide stimulus, PET-AIF, PET-IDIF, and ASL were 64 (55; 74), 76 (70; 83) and 79 (67; 92) mL/100 g per minute, respectively. At baseline, differences between PET-AIF, PET-IDIF, and ASL were 22% ( P < 0.0001) and −0.7% ( P = 0.9). At acetazolamide, differences between PET-AIF, PET-IDIF, and ASL were 19% ( P = 0.001) and 24% ( P = 0.0003). In conclusion, PET-IDIF overestimated CBF. Injected activity of 20 MBq 15O-water had acceptable concordance with 100 MBq, without compromising image quality. Single TI ASL was questionable for regional CBF measurements. Global ASL CBF and PET CBF were congruent during baseline but not during hyperperfusion.

Pressure Autoregulation and Positron Emission Tomography-derived Cerebral Blood Flow Acetazolamide Reactivity in Patients with Carotid Artery Stenosis

Neurosurgery ◽  
2004 ◽  
Vol 55 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Pawan S. Minhas ◽  
Piotr Smielewski ◽  
Peter J. Kirkpatrick ◽  
John D. Pickard ◽  
Marek Czosnyka
Keyword(s):  
Blood Pressure ◽  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Arterial Disease ◽  
Emission Tomography ◽  
Positron Emission ◽  
Carotid Arterial ◽  
Pressure Autoregulation

Abstract OBJECTIVE: Testing autoregulation is of importance in predicting risk of stroke and managing patients with occlusive carotid arterial disease. The use of small spontaneous changes in arterial blood pressure and transcranial Doppler (TCD) flow velocity can be used to assess autoregulation noninvasively without the need for a cerebrovascular challenge. We have previously described an index (called “Mx”) that achieves this. Negative or low positive values (&lt;0.4) indicate intact pressure autoregulation, whereas an Mx greater than 0.4 indicates diminished autoregulation. The objective of this study was to compare acetazolamide reactivity of positron emission tomography (PET)-derived cerebral blood flow (CBF) with Mx in patients with carotid arterial disease. METHODS: In 40 patients with carotid arterial disease, we used bilateral TCD recordings of the middle cerebral artery to derive Mx and compared this with PET-derived CBF measurements of acetazolamide reactivity. RESULTS: Mx correlated inversely with baseline PET CBF (P = 0.042, R = −0.349) but not with postacetazolamide CBF or cerebrovascular reactivity to acetazolamide. This may reflect discordance between pressure autoregulation and acetazolamide reactivity. Mx correlated significantly with degree of internal carotid artery stenosis (P = 0.022, R = 0.38), whereas CBF reactivity to acetazolamide did not correlate with Mx (P = 0.22). After the administration of acetazolamide, slow-wave activity in blood pressure and TCD flow velocity recordings was seen to diminish, rendering the calculation of Mx unreliable after acetazolamide. CONCLUSION: The measurement of Mx offers a noninvasive, safe technique for assessing abnormalities of pressure autoregulation in patients with carotid arterial disease.

scholarly journals Semi-quantitative cerebral blood flow parameters derived from non-invasive [15O]H2O PET studies

2017 ◽  
Vol 39 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Thomas Koopman ◽  
Maqsood Yaqub ◽  
Dennis FR Heijtel ◽  
Aart J Nederveen ◽  
Bart NM van Berckel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Input Function ◽  
Input Function ◽  
Time Activity ◽  
Non Invasive ◽  
Flow Parameters ◽  
Positron Emission ◽  
Arterial Sampling ◽  
Activity Curve

Quantification of regional cerebral blood flow (CBF) using [15O]H2O positron emission tomography (PET) requires the use of an arterial input function. Arterial sampling, however, is not always possible, for example in ill-conditioned or paediatric patients. Therefore, it is of interest to explore the use of non-invasive methods for the quantification of CBF. For validation of non-invasive methods, test–retest normal and hypercapnia data from 15 healthy volunteers were used. For each subject, the data consisted of up to five dynamic [15O]H2O brain PET studies of 10 min and including arterial sampling. A measure of CBF was estimated using several non-invasive methods earlier reported in literature. In addition, various parameters were derived from the time-activity curve (TAC). Performance of these methods was assessed by comparison with full kinetic analysis using correlation and agreement analysis. The analysis was repeated with normalization to the whole brain grey matter value, providing relative CBF distributions. A reliable, absolute quantitative estimate of CBF could not be obtained with the reported non-invasive methods. Relative (normalized) CBF was best estimated using the double integration method.

scholarly journals Effects of Acetazolamide on Cerebral Blood Flow, Blood Volume, and Oxygen Metabolism: A Positron Emission Tomography Study with Healthy Volunteers

2001 ◽  
Vol 21 (12) ◽  
pp. 1472-1479 ◽  
Author(s):  
Hidehiko Okazawa ◽  
Hiroshi Yamauchi ◽  
Kanji Sugimoto ◽  
Hiroshi Toyoda ◽  
Yoshihiko Kishibe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Capillary Blood ◽  
Emission Tomography ◽  
Positron Emission ◽  
Capillary Blood Volume

To evaluate changes in cerebral hemodynamics and metabolism induced by acetazolamide in healthy subjects, positron emission tomography studies for measurement of cerebral perfusion and oxygen consumption were performed. Sixteen healthy volunteers underwent positron emission tomography studies with15O-gas and water before and after intravenous administration of acetazolamide. Dynamic positron emission tomography data were acquired after bolus injection of H215O and bolus inhalation of15O2. Cerebral blood flow, metabolic rate of oxygen, and arterial-to-capillary blood volume images were calculated using the three-weighted integral method. The images of cerebral blood volume were calculated using the bolus inhalation technique of C15O. The scans for cerebral blood flow and volume and metabolic rate of oxygen after acetazolamide challenge were performed at 10, 20, and 30 minutes after drug injection. The parametric images obtained under the two conditions at baseline and after acetazolamide administration were compared. The global and regional values for cerebral blood flow and volume and arterial-to-capillary blood volume increased significantly after acetazolamide administration compared with the baseline condition, whereas no difference in metabolic rate of oxygen was observed. Acetazolamide-induced increases in both blood flow and volume in the normal brain occurred as a vasodilatory reaction of functioning vessels. The increase in arterial-to-capillary blood volume made the major contribution to the cerebral blood volume increase, indicating that the raise in cerebral blood flow during the acetazolamide challenge is closely related to arterial-to-capillary vasomotor responsiveness.

Neural Mechanism of Propofol Anesthesia in Severe Depression

2003 ◽  
Vol 98 (5) ◽  
pp. 1101-1111 ◽  
Author(s):  
Kenichi Ogawa ◽  
Takeshi Uema ◽  
Nobutaka Motohashi ◽  
Masami Nishikawa ◽  
Harumasa Takano ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Statistical Parametric Mapping ◽  
Severe Depression ◽  
Dose Effect ◽  
Emission Tomography ◽  
Association Cortex ◽  
Depressed Patients ◽  
Positron Emission

Background The precise neural mechanisms of propofol anesthesia in humans are still unknown. The authors examined the acute effects of propofol on regional cerebral blood flow (rCBF) using positron emission tomography in patients with severe depression. Methods In six severely depressed patients (mean age, 55.0 yr) scheduled for electroconvulsive therapy, anesthetic levels were monitored by electroencephalography, and rCBF was serially quantified in the awake, sedated, and anesthetized states. The authors used high-resolution positron emission tomography with 15O-labeled water and statistical parametric mapping 99 for imaging and analysis of the data. Results Global cerebral blood flow showed sharp decreases from the awake level during the administration of propofol, decreasing 26.8% in the sedated state and 54.4% in the anesthetized state. Moreover, a dose effect was seen in both parietal cortices and the left lateral prefrontal region with larger regions of relative decrease in rCBF at higher propofol doses. At the higher dose, the values of rCBF in the pulvinar nucleus of the thalamus, the pontine tegmentum, and the cerebellar cortex were also affected. Meanwhile, there were few changes of relative rCBF in the basal frontal lobes during both sedated and anesthetized states. Conclusions As in earlier studies using normal subjects, pronounced suppression in rCBF in the brain stem reticular formation, the thalamus, and the parietal association cortex occurred even in severely depressed patients. However, previously reported decreases in rCBF in the basal frontal lobe were absent in depressed patients.

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