Echo-planar MR cerebral blood volume mapping of glomas. Clinical utility

International Nuclear Information System (INIS)

Aronen, H.J.; Univ. Central Hospital, Helsinki; Glass, J.; Pardo, F.S.; Belliveau, J.W.; Gruber, M.L.; Buchbinder, B.R.; Gazit, I.E.; Linggood, R.M.; Fischman, A.J.; Rosen, F.S.; Hochberg, F.H.

1995-01-01

Neovascularization is a common phenomenon in gliomas. MR imaging cerebral blood volume (CBV) mapping utilizes ultrafast echo-planar imaging and simultaneous use of gadolinium-based contrast material. To determine the utility of MR CBV mapping in the clinical evaluation of gliomas, we followed 15 patients with serial studies. This technique provided functional information that was not evident with conventional CT or MR imaging. Low-grade tumors demonstrated homogeneously low CBV, while high-grade tumors often showed areas of both high and low CBV. The maximum tumor CBV/white matter ratio was compared between low- (n=3) and high-grade gliomas (n=5) in patients without previous treatment and with histologic verification (n=8) and was significantly higher in high-grade gliomas (p<0.01), High CBV foci in nonenhancing tumor areas were present in 2 cases. The distinction between radiation necrosis and active tumor could be made correctly in 3 of 4 cases. The information provided by MR CBV mapping has the potential to be an adjunct in the clinical care of glioma patients. (orig.)

Relative cerebral blood volume as a marker of durable tissue-at-risk viability in hyperacute ischemic stroke.

Science.gov (United States)

Cortijo, Elisa; Calleja, Ana Isabel; García-Bermejo, Pablo; Mulero, Patricia; Pérez-Fernández, Santiago; Reyes, Javier; Muñoz, Ma Fe; Martínez-Galdámez, Mario; Arenillas, Juan Francisco

2014-01-01

Selection of best responders to reperfusion therapies could be aided by predicting the duration of tissue-at-risk viability, which may be dependant on collateral circulation status. We aimed to identify the best predictor of good collateral circulation among perfusion computed tomography (PCT) parameters in middle cerebral artery (MCA) ischemic stroke and to analyze how early MCA response to intravenous thrombolysis and PCT-derived markers of good collaterals interact to determine stroke outcome. We prospectively studied patients with acute MCA ischemic stroke treated with intravenous thrombolysis who underwent PCT before treatment showing a target mismatch profile. Collateral status was assessed using a PCT source image-based score. PCT maps were quantitatively analyzed. Cerebral blood volume (CBV), cerebral blood flow, and Tmax were calculated within the hypoperfused volume and in the equivalent region of unaffected hemisphere. Occluded MCAs were monitored by transcranial Duplex to assess early recanalization. Main outcome variables were brain hypodensity volume and modified Rankin scale score at day 90. One hundred patients with MCA ischemic stroke imaged by PCT received intravenous thrombolysis, and 68 met all inclusion criteria. A relative CBV (rCBV) >0.93 emerged as the only predictor of good collaterals (odds ratio, 12.6; 95% confidence interval, 2.9-55.9; P=0.001). Early MCA recanalization was associated with better long-term outcome and lower infarct volume in patients with rCBV<0.93, but not in patients with high rCBV. None of the patients with rCBV<0.93 achieved good outcome in absence of early recanalization. High rCBV was the strongest marker of good collaterals and may characterize durable tissue-at-risk viability in hyperacute MCA ischemic stroke.

Elevation of the correlation between cerebral blood volume and permeability surface from CT perfusion images with glioma grade

International Nuclear Information System (INIS)

Ding Bei; Ling Huawei; Zhang Huan; Song Qi; Dong Haipeng; Chen Kemin

2007-01-01

Objective: To evaluate the correlation between cerebral blood volume and permeability surface by using multislice CT perfusion imaging with glioma grade. Methods: Ninteen patients with gliomas underwent conventional MR and multislice CT perfusion imaging preoperatively. These patients were divided into low grade and high grade groups which were correspond to WHO II grade gliomas and WHO III or IV grade gliomas respectively. CT data were transferred to on-line working station and processed to obtain time-signal curves, color perfusion maps and calculated perfusion parameters, including cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTF) and permeability surfaces (PS) in tumoral parenchyma. Kruskal-Wallis test and correlation of CBV and PS was assessed by using SPSS 11.0 software. Results: The median of CBV and PS in low-grade and high-grade glioma were 2.7, 6.5 ml/100 g; 0.389, 12.810 ml·100 g -1 ·min -1 respectively, corresponding t value were 12.907 13.500 with P<0.05. Pearson correlations between CBV and PS were as follows: in low-grade group, r=-0.058, in high-grade group, r=0.648. Conclusion: Both CBV and PS have obvious correlation with glioma grade. The correlation between CBV and PS in low-grade glioma was weaker, probably because of the focal high vascularity in oligodendroglioma. (authors)

MRI assessment of cerebral blood volume in patients with brain infarcts

International Nuclear Information System (INIS)

Wu, R.H.; Bruening, R.; Berchtenbreiter, C.; Weber, J.; Peller, M.; Penzkofer, H.; Reiser, M.; Steiger, H.J.

1998-01-01

MRI perfusion studies have focussed mainly on acute ischaemia and characterisation in ischaemia. Our purpose was to analyse regional brain haemodynamic information in acute, subacute, and chronic ischaemia. We performed 16 examinations of 11 patients on a 1.5 T MR images. Conventional and dynamic contrast-enhanced imaging were employed in all examinations. For the dynamic susceptibility sequences, a bolus (0.2 mmol/kg) of gadopentetate dimeglumine was injected. Reconstructed regional relative cerebral blood volume (rCBV) maps, bolus maps, and conventional images were analysed by consensus reading. In all examinations decreases in rCBV were observed in the lesions. The distribution of regional rCBV in lesions was heterogeneous. The rCBV of the periphery of the lesions was higher than that at their center. There was a correlation between the time since onset and abnormalities on the rCBV map and T2-weighted images (T2WI). In the early stage of acute stroke, the abnormalities tended to be larger on the rCBV than on T2WI. Many patterns of bolus passage were observed in ischaemic regions. rCBV maps provide additional haemodynamic information in patients with brain infarcts. (orig.)

Relationship between relative cerebral blood flow, relative cerebral blood volume, and relative cerebral metabolic rate of oxygen in the preterm neonatal brain.

Science.gov (United States)

Nourhashemi, Mina; Kongolo, Guy; Mahmoudzadeh, Mahdi; Goudjil, Sabrina; Wallois, Fabrice

2017-04-01

The mechanisms responsible for coupling between relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative cerebral metabolic rate of oxygen ([Formula: see text]), an important function of the microcirculation in preterm infants, remain unclear. Identification of a causal relationship between rCBF-rCBV and [Formula: see text] in preterms may, therefore, help to elucidate the principles of cortical hemodynamics during development. We simultaneously recorded rCBF and rCBV and estimated [Formula: see text] by two independent acquisition systems: diffuse correlation spectroscopy and near-infrared spectroscopy, respectively, in 10 preterms aged between 28 and 35 weeks of gestational age. Transfer entropy was calculated in order to determine the directionality between rCBF-rCBV and [Formula: see text]. The surrogate method was applied to determine statistical significance. The results show that rCBV and [Formula: see text] have a predominant driving influence on rCBF at the resting state in the preterm neonatal brain. Statistical analysis robustly detected the correct directionality of rCBV on rCBF and [Formula: see text] on rCBF. This study helps to clarify the early organization of the rCBV-rCBF and [Formula: see text] inter-relationship in the immature cortex.

SU-G-IeP1-12: Size Selective Arterial Cerebral Blood Volume Mapping Using Multiple Inversion Time Arterial Spin Labeling

Energy Technology Data Exchange (ETDEWEB)

Jung, Y; Johnston, M; Whitlow, C [Wake Forest School of Medicine, Winston-salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To demonstrate the feasibility of a novel method for size specific arterial cerebral blood volume (aCBV) mapping using pseudo-continuous arterial spin labeling (PCASL), with multiple TI. Methods: Multiple PCASL images were obtained from a subject with TI of [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms. Each TI pair was averaged six times. Two scans were performed: one without a flow crusher gradient and the other with a crusher gradient (10cm/s in three directions) to remove signals from large arteries. Scan times were 5min. without a crusher gradient and 5.5 min with a crusher gradient. Non-linear fitting algorithm finds the minimum mean squared solution of per-voxel based aCBV, cerebral blood flow, and arterial transit time, and fits the data into a hemodynamic model that represents superposition of blood volume and flow components within a single voxel. Results: aCBV maps with a crusher gradient represent signals from medium and small sized arteries, while those without a crusher gradient represent signals from all sized arteries, indicating that flow crusher gradients can be effectively employed to achieve size-specific aCBV mapping. Regardless of flow crusher, the CBF and ATT maps are very similar in appearance. Conclusion: Quantitative size selective blood volume mapping controlled by a flow crusher is feasible without additional information because the ASL quantification process doesn’t require an arterial input function measured from a large artery. The size specific blood volume mapping is not interfered by sSignals from large arteries do not interfere with size specific aCBV mapping in the applications of interest in for applications in which only medium or small arteries are of interest.

Effects of transjugular intrahepatic portosystemic shunt (TIPS) on blood volume distribution in patients with cirrhosis

DEFF Research Database (Denmark)

Busk, Troels M; Bendtsen, Flemming; Henriksen, Jens H

2017-01-01

increased (+22%, prestores central hypovolaemia......BACKGROUND: Cirrhosis is accompanied by portal hypertension with splanchnic and systemic arterial vasodilation, and central hypovolaemia. A transjugular intrahepatic portosystemic shunt (TIPS) alleviates portal hypertension, but also causes major haemodynamic changes. AIMS: To investigate effects...... catheterization. Central and arterial blood volume (CBV) and cardiac output (CO) were determined with indicator dilution technique. RESULTS: After TIPS, the thoracic blood volume increased (+10.4% of total blood volume (TBV), p

Cerebral blood volume imaging by flat detector computed tomography in comparison to conventional multislice perfusion CT

International Nuclear Information System (INIS)

Struffert, Tobias; Kloska, Stephan; Engelhorn, Tobias; Doerfler, Arnd; Deuerling-Zheng, Yu; Boese, Jan; Zellerhoff, Michael; Schwab, Stefan

2011-01-01

We tested the hypothesis that Flat Detector computed tomography (FD-CT) with intravenous contrast medium would allow the calculation of whole brain cerebral blood volume (CBV) mapping (FD-CBV) and would correlate with multislice Perfusion CT (PCT). Twenty five patients were investigated with FD-CBV and PCT. Correlation of the CBV maps of both techniques was carried out with measurements from six anatomical regions from both sides of the brain. Mean values of each region and the correlation coefficient were calculated. Bland-Altman analysis was performed to compare the two different imaging techniques. The image and data quality of both PCT and FD-CBV were suitable for evaluation in all patients. The mean CBV values of FD-CBV and PCT showed only minimal differences with overlapping standard deviation. The correlation coefficient was 0.79 (p < 0.01). Bland-Altman analysis showed a mean difference of -0.077 ± 0.48 ml/100 g between FD-CBV and PCT CBV measurements, indicating that FD-CBV values were only slightly lower than those of PCT. CBV mapping with intravenous contrast medium using Flat Detector CT compared favourably with multislice PCT. The ability to assess cerebral perfusion within the angiographic suite may improve the management of ischaemic stroke and evaluation of the efficacy of dedicated therapies. (orig.)

Human cerebral blood volume measurements using dynamic contrast enhancement in comparison to dynamic susceptibility contrast MRI

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Artzi, Moran [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Liberman, Gilad; Vitinshtein, Faina; Aizenstein, Orna [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Nadav, Guy [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Faculty of Engineering, Tel Aviv (Israel); Blumenthal, Deborah T.; Bokstein, Felix [Tel Aviv Sourasky Medical Center, Neuro-Oncology Service, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv Sourasky Medical Center, Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv (Israel)

2015-07-15

Cerebral blood volume (CBV) is an important parameter for the assessment of brain tumors, usually obtained using dynamic susceptibility contrast (DSC) MRI. However, this method often suffers from low spatial resolution and high sensitivity to susceptibility artifacts and usually does not take into account the effect of tissue permeability. The plasma volume (v{sub p}) can also be extracted from dynamic contrast enhancement (DCE) MRI. The aim of this study was to investigate whether DCE can be used for the measurement of cerebral blood volume in place of DSC for the assessment of patients with brain tumors. Twenty-eight subjects (17 healthy subjects and 11 patients with glioblastoma) were scanned using DCE and DSC. v{sub p} and CBV values were measured and compared in different brain components in healthy subjects and in the tumor area in patients. Significant high correlations were detected between v{sub p} and CBV in healthy subjects in the different brain components; white matter, gray matter, and arteries, correlating with the known increased tissue vascularity, and within the tumor area in patients. This work proposes the use of DCE as an alternative method to DSC for the assessment of blood volume, given the advantages of its higher spatial resolution, its lower sensitivity to susceptibility artifacts, and its ability to provide additional information regarding tissue permeability. (orig.)

Rapid multi-wavelength optical assessment of circulating blood volume without a priori data

Science.gov (United States)

Loginova, Ekaterina V.; Zhidkova, Tatyana V.; Proskurnin, Mikhail A.; Zharov, Vladimir P.

2016-03-01

The measurement of circulating blood volume (CBV) is crucial in various medical conditions including surgery, iatrogenic problems, rapid fluid administration, transfusion of red blood cells, or trauma with extensive blood loss including battlefield injuries and other emergencies. Currently, available commercial techniques are invasive and time-consuming for trauma situations. Recently, we have proposed high-speed multi-wavelength photoacoustic/photothermal (PA/PT) flow cytometry for in vivo CBV assessment with multiple dyes as PA contrast agents (labels). As the first step, we have characterized the capability of this technique to monitor the clearance of three dyes (indocyanine green, methylene blue, and trypan blue) in an animal model. However, there are strong demands on improvements in PA/PT flow cytometry. As additional verification of our proof-of-concept of this technique, we performed optical photometric CBV measurements in vitro. Three label dyes—methylene blue, crystal violet and, partially, brilliant green—were selected for simultaneous photometric determination of the components of their two-dye mixtures in the circulating blood in vitro without any extra data (like hemoglobin absorption) known a priori. The tests of single dyes and their mixtures in a flow system simulating a blood transfusion system showed a negligible difference between the sensitivities of the determination of these dyes under batch and flow conditions. For individual dyes, the limits of detection of 3×10-6 M‒3×10-6 M in blood were achieved, which provided their continuous determination at a level of 10-5 M for the CBV assessment without a priori data on the matrix. The CBV assessment with errors no higher than 4% were obtained, and the possibility to apply the developed procedure for optical photometric (flow cytometry) with laser sources was shown.

Magnetic resonance imaging as a diagnostic method for assessing function. New procedures for the non-invasive quantification of cerebral blood volume and blood flow

International Nuclear Information System (INIS)

Gueckel, F.; Rempp, K.; Becker, G.; Koepke, J.; Loose, R.; Brix, G.

1994-01-01

This paper presents a brief introduction to the current status of cerebral blood volume and blood flow imaging with magnetic resonance imaging (MRI) techniques. A new method for the quantitative assessment of regional cerebral blood volume (rCBV) and regional cerebral blood flow (rCBF) on the basis of the indicator dilution theory is described and preliminary quantitative results from healthy volunteers are presented. The mean values for the rCBV are 8,27±1,85 ml/100 g for grey matter and 3,78±1,34 ml/100 g for white matter. The mean values for the rCBF are 44,8±11,29 ml/min/100 g for the grey matter and 20,88±8,42 ml/min/100 g for the white matter. These results are in good agreement with PET results from the literature. (orig.) [de

Precision of a new bedside method for estimation of the circulating blood volume

DEFF Research Database (Denmark)

Christensen, P; Eriksen, B; Henneberg, S W

1993-01-01

The present study is a theoretical and experimental evaluation of a modification of the carbon monoxide method for estimation of the circulating blood volume (CBV) with respect to the precision of the method. The CBV was determined from measurements of the CO-saturation of hemoglobin before...... ventilation with the CO gas mixture. The amount of CO administered during each determination of CBV resulted in an increase in the CO saturation of hemoglobin of 2.1%-3.9%. A theoretical noise propagation analysis was performed by means of the Monte Carlo method. The analysis showed that a CO dose...... patients. The coefficients of variation were 6.2% and 4.7% in healthy and diseased subjects, respectively. Furthermore, the day-to-day variation of the method with respect to the total amount of circulating hemoglobin (nHb) and CBV was determined from duplicate estimates separated by 24-48 h. In conclusion...

Sequential assessment of regional cerebral blood flow, regional cerebral blood volume, and blood-brain barrier in focal cerebral ischemia: a case report

International Nuclear Information System (INIS)

Di Piero, V.; Perani, D.; Savi, A.; Gerundini, P.; Lenzi, G.L.; Fazio, F.

1986-01-01

Regional CBF (rCBF) and regional cerebral blood volume (rCBV) were evaluated by N,N,N'-trimethyl-N'-(2)-hydroxy-3-methyl-5-[123I]iodobenzyl-1, 3-propanediamine-2 HCl- and /sup 99m/TC-labeled red blood cells, respectively, and single-photon emission computerized tomography (SPECT) in a patient with focal cerebral ischemia. Sequential transmission computerized tomography (TCT) and SPECT functional data were compared with clinical findings to monitor the pathophysiological events occurring in stroke. A lack of correlation between rCBF-rCBV distributions and blood-brain barrier (BBB) breakdown was found in the acute phase. In the face of more prolonged alteration of BBB, as seen by TCT enhancement, a rapid evolution of transient phenomena such as luxury perfusion was shown by SPECT studies. Follow-up of the patient demonstrated a correlation between the neurological recovery and a parallel relative improvement of the cerebral perfusion

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma.

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Göttler, Jens; Lukas, Mathias; Kluge, Anne; Kaczmarz, Stephan; Gempt, Jens; Ringel, Florian; Mustafa, Mona; Meyer, Bernhard; Zimmer, Claus; Schwaiger, Markus; Förster, Stefan; Preibisch, Christine; Pyka, Thomas

2017-03-01

18 F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology.

Intra-lesional spatial correlation of static and dynamic FET-PET parameters with MRI-based cerebral blood volume in patients with untreated glioma

Energy Technology Data Exchange (ETDEWEB)

Goettler, Jens; Preibisch, Christine [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); Lukas, Mathias; Mustafa, Mona; Schwaiger, Markus; Pyka, Thomas [TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Kluge, Anne; Kaczmarz, Stephan; Zimmer, Claus [TU Muenchen, Department of Neuroradiology, Klinikum rechts der Isar, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [TU Muenchen, Department of Neurosurgery, Klinikum rechts der Isar, Munich (Germany); Foerster, Stefan [TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Klinikum rechts der Isar, Munich (Germany); TU Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Klinikum Bayreuth, Department of Nuclear Medicine, Bayreuth (Germany)

2017-03-15

{sup 18}F-fluorethyltyrosine-(FET)-PET and MRI-based relative cerebral blood volume (rCBV) have both been used to characterize gliomas. Recently, inter-individual correlations between peak static FET-uptake and rCBV have been reported. Herein, we assess the local intra-lesional relation between FET-PET parameters and rCBV. Thirty untreated glioma patients (27 high-grade) underwent simultaneous PET/MRI on a 3 T hybrid scanner obtaining structural and dynamic susceptibility contrast sequences. Static FET-uptake and dynamic FET-slope were correlated with rCBV within tumour hotspots across patients and intra-lesionally using a mixed-effects model to account for inter-individual variation. Furthermore, maximal congruency of tumour volumes defined by FET-uptake and rCBV was determined. While the inter-individual relationship between peak static FET-uptake and rCBV could be confirmed, our intra-lesional, voxel-wise analysis revealed significant positive correlations (median r = 0.374, p < 0.0001). Similarly, significant inter- and intra-individual correlations were observed between FET-slope and rCBV. However, rCBV explained only 12% of the static and 5% of the dynamic FET-PET variance and maximal overlap of respective tumour volumes was 37% on average. Our results show that the relation between peak values of MR-based rCBV and static FET-uptake can also be observed intra-individually on a voxel basis and also applies to a dynamic FET parameter, possibly determining hotspots of higher biological malignancy. However, just a small part of the FET-PET signal variance is explained by rCBV and tumour volumes determined by the two modalities showed only moderate overlap. These findings indicate that FET-PET and MR-based rCBV provide both congruent and complimentary information on glioma biology. (orig.)

Whole-tumor histogram analysis of the cerebral blood volume map: tumor volume defined by 11C-methionine positron emission tomography image improves the diagnostic accuracy of cerebral glioma grading.

Science.gov (United States)

Wu, Rongli; Watanabe, Yoshiyuki; Arisawa, Atsuko; Takahashi, Hiroto; Tanaka, Hisashi; Fujimoto, Yasunori; Watabe, Tadashi; Isohashi, Kayako; Hatazawa, Jun; Tomiyama, Noriyuki

2017-10-01

This study aimed to compare the tumor volume definition using conventional magnetic resonance (MR) and 11C-methionine positron emission tomography (MET/PET) images in the differentiation of the pre-operative glioma grade by using whole-tumor histogram analysis of normalized cerebral blood volume (nCBV) maps. Thirty-four patients with histopathologically proven primary brain low-grade gliomas (n = 15) and high-grade gliomas (n = 19) underwent pre-operative or pre-biopsy MET/PET, fluid-attenuated inversion recovery, dynamic susceptibility contrast perfusion-weighted magnetic resonance imaging, and contrast-enhanced T1-weighted at 3.0 T. The histogram distribution derived from the nCBV maps was obtained by co-registering the whole tumor volume delineated on conventional MR or MET/PET images, and eight histogram parameters were assessed. The mean nCBV value had the highest AUC value (0.906) based on MET/PET images. Diagnostic accuracy significantly improved when the tumor volume was measured from MET/PET images compared with conventional MR images for the parameters of mean, 50th, and 75th percentile nCBV value (p = 0.0246, 0.0223, and 0.0150, respectively). Whole-tumor histogram analysis of CBV map provides more valuable histogram parameters and increases diagnostic accuracy in the differentiation of pre-operative cerebral gliomas when the tumor volume is derived from MET/PET images.

Does helmet CPAP reduce cerebral blood flow and volume by comparison with Infant Flow driver CPAP in preterm neonates?

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Zaramella, Patrizia; Freato, Federica; Grazzina, Nicoletta; Saraceni, Elisabetta; Vianello, Andrea; Chiandetti, Lino

2006-10-01

We compared neonatal helmet continuous positive airway pressure (CPAP) and the conventional nasal Infant Flow driver (IFD) CPAP in the noninvasive assessment of absolute cerebral blood flow (CBF) and relative cerebral blood volume changes (DeltaCBV) by near-infrared spectroscopy. A randomized crossover study in a tertiary referral NICU. Assessment of CBF and DeltaCBV in 17 very low birth weight infants with respiratory distress (median age 5 days) treated with two CPAP devices at a continuous distending pressure of 4 mbar. Neonates were studied for two consecutive 60-min periods with helmet CPAP and with IFD CPAP. Basal chromophore traces enabled DeltaCBV changes to be calculated. CBF was calculated in milliliters per 100 grams per minute from the saturation rise integral and rate of rise O(2)Hb-HHb. Median (range) CBF with helmet CPAP was 27.37 (9.47-48.20) vs. IFD CBF 34.74 (13.59-60.10)(p=0.049) and DeltaCBV 0.15 (0.09-0.28) with IFD and 0.13 (0.07-0.27) with helmet CPAP (NS). Using helmet and IFD CPAP, the neonates showed no difference in mean physiological parameters (transcutaneous carbon dioxide and oxygen tension, pulse oximetry saturation, heart rate, breathing rate, mean arterial blood pressure, desaturation rate, axillary temperature). Assessing CBF and DeltaCBV measured by near-infrared spectroscopy with two CPAP devices revealed no differences in relative blood volume, but CBF was lower with helmet CPAP. Greater active vasoconstriction and/or passive capillary and/or venous vessel compression seem the most likely reason, due to a positive pressure around the head, neck, and shoulders by comparison with the airway pressure.

Gliomas: Application of Cumulative Histogram Analysis of Normalized Cerebral Blood Volume on 3 T MRI to Tumor Grading

Science.gov (United States)

Kim, Hyungjin; Choi, Seung Hong; Kim, Ji-Hoon; Ryoo, Inseon; Kim, Soo Chin; Yeom, Jeong A.; Shin, Hwaseon; Jung, Seung Chai; Lee, A. Leum; Yun, Tae Jin; Park, Chul-Kee; Sohn, Chul-Ho; Park, Sung-Hye

2013-01-01

Background Glioma grading assumes significant importance in that low- and high-grade gliomas display different prognoses and are treated with dissimilar therapeutic strategies. The objective of our study was to retrospectively assess the usefulness of a cumulative normalized cerebral blood volume (nCBV) histogram for glioma grading based on 3 T MRI. Methods From February 2010 to April 2012, 63 patients with astrocytic tumors underwent 3 T MRI with dynamic susceptibility contrast perfusion-weighted imaging. Regions of interest containing the entire tumor volume were drawn on every section of the co-registered relative CBV (rCBV) maps and T2-weighted images. The percentile values from the cumulative nCBV histograms and the other histogram parameters were correlated with tumor grades. Cochran’s Q test and the McNemar test were used to compare the diagnostic accuracies of the histogram parameters after the receiver operating characteristic curve analysis. Using the parameter offering the highest diagnostic accuracy, a validation process was performed with an independent test set of nine patients. Results The 99th percentile of the cumulative nCBV histogram (nCBV C99), mean and peak height differed significantly between low- and high-grade gliomas (P = histogram analysis of nCBV using 3 T MRI can be a useful method for preoperative glioma grading. The nCBV C99 value is helpful in distinguishing high- from low-grade gliomas and grade IV from III gliomas. PMID:23704910

The effect of glycerol on regional cerebral blood flow, blood volume and oxygen metabolism

International Nuclear Information System (INIS)

Ishikawa, Masatsune; Kikuchi, Haruhiko; Nagata, Izumi; Yamagata, Sen; Taki, Waro; Kobayashi, Akira; Yonekura, Yoshiharu; Nishizawa, Sadahiko.

1989-01-01

Using positron emission tomography with 15 O-labelled CO 2 , O 2 and CO gases, the effects of glycerol on regional cerebral blood flow (CBF), blood volume (CBV) and oxygen metabolism (CMRO 2 ) were investigated in 6 patients with meningioma accompanying peritumoral brain edema. The same study was done in 5 normal volunteers. The changes of blood gases, hematocrit and hemoglobin were also examined. After a drip infusion of glycerol, the regional CBF increased not only in the peritumoral cortex and white matter but also in the intact cortex and white matter on the contralateral side. The increase of CBF was extensive and substantially there were no regional differences. In contrast, the changes of CMRO 2 were not significant. This was derived from the increase in oxygen extraction fraction throughout extensive areas including the peritumoral area. There were no changes in CBV. Hematocrit and hemoglobin decreased to a small degree. In the normal volunteers, the same findings were noted. Thus, glycerol increases the functional reserve for cerebral oxygen metabolism, not only in the peritumoral regions but also in the intact regions. The effects of glycerol on hemodynamics and metabolism were discussed with reference to some differences from mannitol. (author)

Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

DEFF Research Database (Denmark)

Rostrup, Egill; Larsson, H B; Toft, P B

1996-01-01

PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...

Energetic Interrelationship between Spontaneous Low-Frequency Fluctuations in Regional Cerebral Blood Volume, Arterial Blood Pressure, Heart Rate, and Respiratory Rhythm

Science.gov (United States)

Katura, Takusige; Yagyu, Akihiko; Obata, Akiko; Yamazaki, Kyoko; Maki, Atsushi; Abe, Masanori; Tanaka, Naoki

2007-07-01

Strong spontaneous fluctuations around 0.1 and 0.3 Hz have been observed in blood-related brain-function measurements such as functional magnetic resonance imaging and optical topography (or functional near-infrared spectroscopy). These fluctuations seem to reflect the interaction between the cerebral circulation system and the systemic circulation system. We took an energetic viewpoint in our analysis of the interrelationships between fluctuations in cerebral blood volume (CBV), mean arterial blood pressure (MAP), heart rate (HR), and respiratory rhythm based on multivariate autoregressive modeling. This approach involves evaluating the contribution of each fluctuation or rhythm to specific ones by performing multivariate spectral analysis. The results we obtained show MAP and HR can account slightly for the fluctuation around 0.1 Hz in CBV, while the fluctuation around 0.3 Hz is derived mainly from the respiratory rhythm. During our presentation, we will report on the effects of posture on the interrelationship between the fluctuations and the respiratory rhythm.

Changes in circulating blood volume after infusion of hydroxyethyl starch 6% in critically ill patients

DEFF Research Database (Denmark)

Christensen, P; Andersson, J; Rasmussen, S E

2001-01-01

The cardiovascular response to a volume challenge with hydroxyethyl starch (HES) (200/0.5) 6% depends on the relation between the volume of HES 6% infused and the expansion of the blood volume in critically ill patients. However, only relatively limited data exist on the plasma expanding effect...... of infusion of HES 6% in critically ill patients. The purpose of the study was to evaluate the variation in the expansion of the circulating blood volume (CBV) in critically ill patients after infusion of 500 ml of colloid (HES (200/0.5) 6%) using the carbon monoxide method....

WE-FG-206-05: New Arterial Spin Labeling Method for Simultaneous Estimation of Arterial Cerebral Blood Volume, Cerebral Blood Flow and Arterial Transit Time

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Johnston, M; Whitlow, C; Jung, Y [Wake Forest School of Medicine, Winston-Salem, NC (United States); Liu, H [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To demonstrate the feasibility of a novel Arterial Spin Labeling (ASL) method for simultaneously measuring cerebral blood flow (CBF), arterial transit time (ATT), and arterial cerebral blood volume (aCBV) without the use of a contrast agent. Methods: A series of multi-TI ASL images were acquired from one healthy subject on a 3T Siemens Skyra, with the following parameters: PCASL labeling with variable TI [300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000] ms, labeling bolus 1400 ms when TI allows, otherwise 100 ms less than TI, TR was minimized for each TI, two sinc shaped pre-saturation pulses were applied in the imaging plane immediately before 2D EPI acquisition. 64×64×24 voxels, 5 mm slice thickness, 1 mm gap, full brain coverage, 6 averages per TI, no crusher gradients, 11 ms TE, scan time of 4:56. The perfusion weighted time-series was created for each voxel and fit to a novel model. The model has two components: 1) the traditional model developed by Buxton et al., accounting for CBF and ATT, and 2) a box car function characterizing the width of the labeling bolus, with variable timing and height in proportion to the aCBV. All three parameters were fit using a nonlinear fitting routine that constrained all parameters to be positive. The main purpose of the high-temporal resolution TI sampling for the first second of data acquisition was to precisely estimate the blood volume component for better detection of arrival time and magnitude of signal. Results: Whole brain maps of CBF, ATT, and aCBV were produced, and all three parameters maps are consistent with similar maps described in the literature. Conclusion: Simultaneous mapping of CBF, ATT, and aCBV is feasible with a clinically tractable scan time (under 5 minutes).

MR-based cerebral blood volume maps as a diagnostic tool of stroke: results of a clinical pilot study

International Nuclear Information System (INIS)

Hacklaender, T.; Hofer, M.; Binkofski, F.; Reichenbach, J.; Moedder, U.

1996-01-01

In this study the sensitivity of proving a stroke using regional cerebral blood volume (rCBV) maps were investigated. Another aim was to evaluate the strength of the ischaemia. Seven patients were examined during the acute phase of a stroke, eight during the subacute or chronically stage. To calculate rCBV-maps of one slice low dosed Gd-DTPA was injected as a bolus. Using the relaxation-effect the obtained signal intensity-time curves were converted pixel-wise to rCBV images. For the region of the infarction rCBV ratios were calculated relative to the corresponding area in the contralateral hemisphere. Only 63% of the investigations carried out during the acute phase were utilizable. In all those cases a decrease of rCBV was found. The infarct area could only be visually recognized if the rCBV ratio was lower than 0.7. The ratios of completely and partical necrotic areas of the infarctions were 0.481 and 1.028 respectively. With a p=0.0015 these values are even statistically different. During the acute stage the sensitivity of the rCBV measurement was not as high as that of morphological MR imaging. However, rCBV maps make it possible to estimate the strength of the ischaemia even during the first hours. (orig./MG) [de

Decreased right heart blood volume determined by magnetic resonance imaging: evidence of central underfilling in cirrhosis

DEFF Research Database (Denmark)

Møller, S; Søndergaard, L; Møgelvang, J

1995-01-01

mL, NS), and left atrial volume (70 vs. 57 mL, P = .08) were normal or slightly increased. The right ejection fraction (68% vs. 53%, P fraction was slightly reduced (61% vs. 69%, NS). The central and arterial blood volume (CBV), assessed......Whether the central blood volume is reduced or expanded in cirrhosis is still under debate. Accordingly, the current study was undertaken to assess the volume of the heart cavities. Ten cirrhotic patients and matched controls had their right and left ventricular end-diastolic volumes (RVDV and LVDV...... as the cardiac output (CO) multiplied by the central circulation time, was significantly decreased (1.47 vs. 1.81 L, P blood volume (4.43 vs. 3.64 L, P

Relative cerebral blood volume is associated with collateral status and infarct growth in stroke patients in SWIFT PRIME.

Science.gov (United States)

Arenillas, Juan F; Cortijo, Elisa; García-Bermejo, Pablo; Levy, Elad I; Jahan, Reza; Goyal, Mayank; Saver, Jeffrey L; Albers, Gregory W

2017-01-01

We aimed to evaluate how predefined candidate cerebral perfusion parameters correlate with collateral circulation status and to assess their capacity to predict infarct growth in patients with acute ischemic stroke (AIS) eligible for endovascular therapy. Patients enrolled in the SWIFT PRIME trial with baseline computed tomography perfusion (CTP) scans were included. RAPID software was used to calculate mean relative cerebral blood volume (rCBV) in hypoperfused regions, and hypoperfusion index ratio (HIR). Blind assessments of collaterals were performed using CT angiography in the whole sample and cerebral angiogram in the endovascular group. Reperfusion was assessed on 27-h CTP; infarct volume was assessed on 27-h magnetic resonance imaging/CT scans. Logistic and rank linear regression models were conducted. We included 158 patients. High rCBV ( p = 0.03) and low HIR ( p = 0.03) were associated with good collaterals. A positive association was found between rCBV and better collateral grades on cerebral angiography ( p = 0.01). Baseline and 27-h follow-up CTP were available for 115 patients, of whom 74 (64%) achieved successful reperfusion. Lower rCBV predicted a higher infarct growth in successfully reperfused patients ( p = 0.038) and in the endovascular treatment group ( p = 0.049). Finally, rCBV and HIR may serve as markers of collateral circulation in AIS patients prior to endovascular therapy. Unique identifier: NCT0165746.

Quantification of regional cerebral blood flow and volume with dynamic susceptibility contrast-enhanced MR imaging.

Science.gov (United States)

Rempp, K A; Brix, G; Wenz, F; Becker, C R; Gückel, F; Lorenz, W J

1994-12-01

Quantification of regional cerebral blood flow (rCBF) and volume (rCBV) with dynamic magnetic resonance (MR) imaging. After bolus administration of a paramagnetic contrast medium, rapid T2*-weighted gradient-echo images of two sections were acquired for the simultaneous creation of concentration-time curves in the brain-feeding arteries and in brain tissue. Absolute rCBF and rCBV values were determined for gray and white brain matter in 12 subjects with use of principles of the indicator dilution theory. The mean rCBF value in gray matter was 69.7 mL/min +/- 29.7 per 100 g tissue and in white matter, 33.6 mL/min +/- 11.5 per 100 g tissue; the average rCBV was 8.0 mL +/- 3.1 per 100 g tissue and 4.2 mL +/- 1.0 per 100 g tissue, respectively. An age-related decrease in rCBF and rCBV for gray and white matter was observed. Preliminary data demonstrate that the proposed technique allows the quantification of rCBF and rCBV. Although the results are in good agreement with data from positron emission tomography studies, further evaluation is needed to establish the validity of method.

The effect of acetazolamide on cerebral blood volume and intracranial pressure in patients with hydrocephalus. Theoretical background of the acetazolamide challenge test

International Nuclear Information System (INIS)

Ogawa, Daiji

2000-01-01

The acetazolamide challenge test is one of the useful tests for diagnosing normal pressure hydrocephalus (NPH). It has the advantage of being less invasive than other tests. However, the manner of increment in cerebral blood volume (CBV) has not been well clarified. Therefore, the theoretical background of the test is also unclear. The aims of this study were to evaluate the effect of acetazolamide on CBV and intracranial pressure (ICP) and elucidate the theoretical background of the test. Thirteen patients with NPH were studied. CBV and ICP were measured before and after the intravenous injection of acetazolamide (1000 mg). CBV was evaluated by means of cerebral pool SPECT; ICP was evaluated by OSAKA telesensor or a pressure transducer via ventricular catheter. Immediately after the injection, CBV increased rapidly, reaching its maximum (15% increase) at 6 minutes. Then CBV gradually decreased. ICP also elevated rapidly, reaching its maximum (12.6 mmHg elevation) at 4 minutes. A gradual decrement ICP was observed, and 26 minutes after injection, the ICP became lower than the pre-injection level. The rapid increase in CBV caused the ICP elevation, and the increment ratio reflected the cerebral compliance. Therefore, we concluded that the acetazolamide challenge test is based on the alteration of cerebral compliance seen in NPH patients. The decrement ratio of ICP is affected not only by the resistance cerebrospinal fluid (CSF) absorption but also by decrease in the CBV and CSF production induced by acetazolamide. Consequently, it is difficult to evaluate the resistance of CSF absorption by this test. Because CBV increased in all cases, it is assumed that acetazolamide administration can be used to reliably load the volume. (author)

Dynamic susceptibility contrast (DSC) perfusion MRI in differential diagnosis between radionecrosis and neoangiogenesis in cerebral metastases using rCBV, rCBF and K2.

Science.gov (United States)

Muto, Mario; Frauenfelder, Giulia; Senese, Rossana; Zeccolini, Fabio; Schena, Emiliano; Giurazza, Francesco; Jäger, Hans Rolf

2018-07-01

Distinction between treatment-related changes and tumour recurrence in patients who have received radiation treatment for brain metastases can be difficult on conventional MRI. In this study, we investigated the ability of dynamic susceptibility contrast (DSC) perfusion in differentiating necrotic changes from pathological angiogenesis and compared measurements of relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF) and K2, using a dedicated software. Twenty-nine patients with secondary brain tumors were included in this retrospective study and underwent DSC perfusion MRI with a 3-month follow-up imaging after chemo- or radiation-therapy. Region-of-interests were drawn around the contrast enhancing lesions and measurements of rCBV, rCBF and K2 were performed in all patients. Based on subsequent histological examination or clinico-radiological follow-up, the cohort was divided in two groups: recurrent disease and stable disease. Differences between the two groups were analyzed using the Student's t test. Sensitivity, specificity and diagnostic accuracy of rCBV measurements were analyzed considering three different cut-off values. Between patients with and without disease, only rCBV and rCBF values were significant (p < 0.05). The only cut-off value giving the best diagnostic accuracy of 100% was rCBV = 2.1 (sensitivity = 100%; specificity = 100%). Patients with tumor recurrence showed a higher mean value of rCBV (mean = 4.28, standard deviation = 2.09) than patients with necrotic-related changes (mean = 0.77, standard deviation = 0.44). DSC-MRI appears a clinically useful method to differentiate between tumor recurrence, tumor necrosis and pseudoprogression in patients treated for cerebral metastases. Relative CBV using a cut-off value of 2.1 proved to be the most accurate and reliable parameter.

Cerebral blood volume changes in cats with acute increased intracranial pressure

International Nuclear Information System (INIS)

Kondo, Takashi; Kano, Mitsumasa; Ikeda, Takuya.

1984-01-01

We measured the changes in cerebral blood volume in cats with increased intracranial pressure with a high-speed CT scanner, employing contrast effects by the iodine agent. In acute increased intracranial pressure caused by raising the extradural pressure by 20 mmHg, cerebral blood volume showed a significant decrease by 32% in comparison with that at normal intracranial pressure. There was also a tendency that a decline of iodine was delayed with time at increased intracranial pressure than that at normal pressure. This was supposed to be a delay of cerebral circulation due to venous congestion. This experimental model and measuring method provide the changes in CBV in the same individual without any tedious procedure, and therefore this is a reliable method with respect to precision. (author)

Determination of the volume of circulating blood by means of in vivo labelled red blood cells with 99mTc pertechnetate and use of a Bulgarian kit

International Nuclear Information System (INIS)

Kostadinova, I.; Shejretova, E.; Pencheva, V.; Udvareva, N.

1988-01-01

A method was proposed for determination of the circulating blood volume (CBV) by means of in vivo labelled red blood cells, which was compared to the routine method with 51 Cr-sodium chromate. To the patients concecutively was given 1 g of potassium perchlorate (for blocking of the organs, which actively absorbed the perchnetate ion) and 500 mkg of tin pyrophosphate (Bulgarian kit) with subsequent labelling of the red blood cells with 99m Tc-pertechnate (1,8 - 3,7 MBq). The volume of the red blood cells, and hence also CBV, was measured with the use of a modified by the authors formula, in which correction for the individual effectiveness of the cell labelling was done. In comparison with the standard method for in vitro labelling of the red blood cells with 51 Cr sodium chromate, the method proposed gave an insignificant difference of 4,16%, but when compared to the commercial tin pyrophosphate (of the firm Mallinckrot - Holland), the Bulgarian kit displayed equivalent qualities. It was concluded that the method has a high accuracy and was easy for execution, cause a low radiation burden of the patient and is suitable for application in nuclear cardiology and radionuclide angiography

Improvements in the Quantitative Assessment of Cerebral Blood Volume and Flow with the Removal of Vessel Voxels from MR Perfusion Images

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Michael Mu Huo Teng

2013-01-01

Full Text Available Objective. To improve the quantitative assessment of cerebral blood volume (CBV and flow (CBF in the brain voxels from MR perfusion images. Materials and Methods. Normal brain parenchyma was automatically segmented with the time-to-peak criteria after cerebrospinal fluid removal and preliminary vessel voxel removal. Two scaling factors were calculated by comparing the relative CBV and CBF of the segmented normal brain parenchyma with the absolute values in the literature. Using the scaling factors, the relative values were converted to the absolute CBV and CBF. Voxels with either CBV > 8 mL/100 g or CBF > 100 mL/100 g/min were characterized as vessel voxels and were excluded from the quantitative measurements. Results. The segmented brain parenchyma with normal perfusion was consistent with the angiographic findings for each patient. We confirmed the necessity of dual thresholds including CBF and CBV for proper removal of vessel voxels. The scaling factors were 0.208 ± 0.041 for CBV, and 0.168 ± 0.037, 0.172 ± 0.037 for CBF calculated using standard and circulant singular value decomposition techniques, respectively. Conclusion. The automatic scaling and vessel removal techniques provide an alternative method for obtaining improved quantitative assessment of CBV and CBF in patients with thromboembolic cerebral arterial disease.

Three-dimensional whole-brain perfused blood volume imaging with multimodal CT for evaluation of acute ischaemic stroke

International Nuclear Information System (INIS)

Lu, J.; Zhang, M.; Cao, Y.; Ma, Q.; Chen, J.; Ji, X.; Li, K.

2011-01-01

Aim: To determine the diagnostic value of integrating three-dimensional perfused blood volume (3D PBV) with multimodal computed tomography (CT) [non-enhanced CT (NECT), CT perfusion (CTP), and CT angiography (CTA)] in acute ischaemic stroke. Materials and methods: NECT, CTP, and CTA were performed in 25 acute ischaemic stroke patients. The ischaemia detection rate of 3D PBV was compared with the results of baseline NECT and CTP. The correlation of ischaemic lesion volume between 3D PBV, CTP images, and follow-up NECT were analysed. Results: NECT demonstrated ischaemic signs in 12 of 25 patients with proven infarction. CTP maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) all demonstrated perfusion deficits in 21 of 25 patients. However, 3D PBV demonstrated perfusion deficits in all of the 25 patients. Among the 25 patients, a strong correlation was found between PBV and the follow-up NECT infarct (r = 0.858). The correlation between CTP and the follow-up NECT infarct as following: CBF (r = 0.718), CBV (r = 0.785), and TTP (r = 0.569). In 14 thrombolytic patients, strong correlation was found between the ischaemic volume on 3D PBV and follow-up NECT (r = 0.798). Conclusion: In acute stroke patients, the combination of 3D PBV and multimodal CT (NECT, CTP, and CTA) can improve the detection rate of ischaemia and enable assessment of the full extent of ischaemia, which correlates well with follow-up NECT.

Amide proton transfer imaging to discriminate between low- and high-grade gliomas: added value to apparent diffusion coefficient and relative cerebral blood volume

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Choi, Yoon Seong; Ahn, Sung Soo; Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, College of Medicine, Seoul (Korea, Republic of); Chang, Jong Hee; Kang, Seok-Gu [Yonsei University College of Medicine, Department of Neurosurgery, Seoul (Korea, Republic of); Kim, Se Hoon [Yonsei University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Zhou, Jinyuan [Johns Hopkins University School of Medicine, Division of MRI Research, Department of Radiology, Baltimore, MD (United States)

2017-08-15

To evaluate the added value of amide proton transfer (APT) imaging to the apparent diffusion coefficient (ADC) from diffusion tensor imaging (DTI) and the relative cerebral blood volume (rCBV) from perfusion magnetic resonance imaging (MRI) for discriminating between high- and low-grade gliomas. Forty-six consecutive adult patients with diffuse gliomas who underwent preoperative APT imaging, DTI and perfusion MRI were enrolled. APT signals were compared according to the World Health Organization grade. The diagnostic ability and added value of the APT signal to the ADC and rCBV for discriminating between low- and high-grade gliomas were evaluated using receiver operating characteristic (ROC) analyses and integrated discrimination improvement. The APT signal increased as the glioma grade increased. The discrimination abilities of the APT, ADC and rCBV values were not significantly different. Using both the APT signal and ADC significantly improved discrimination vs. the ADC alone (area under the ROC curve [AUC], 0.888 vs. 0.910; P = 0.007), whereas using both the APT signal and rCBV did not improve discrimination vs. the rCBV alone (AUC, 0.927 vs. 0.923; P = 0.222). APT imaging may be a useful imaging biomarker that adds value to the ADC for discriminating between low- and high-grade gliomas. (orig.)

Use of the functional imaging modalities, f MRI r CBV and PET FDG, alters radiation therapy 3-D treatment planning in patients with malignant gliomas

International Nuclear Information System (INIS)

Fitzek, M.; Pardo, F.S.; Busierre, M.; Lev, M.; Fischman, A.; Denny, N.; Hanser, B.; Rosen, B.R.; Smith, A.; Aronen, H.

1995-01-01

Background: Malignant gliomas present one of the most difficult challenges to definitive radiation therapy, not only with respect to local control, but also with respect to clinical functional status. While tumor target volume definitions for malignant gliomas are often based on CT and conventional MRI, the functional imaging modalities, echo planar r CBV (regional cerebral blood volume mapping) and 18F-fluorodeoxyglucose PET, are more sensitive modalities for the detection of neovascularization, perhaps one of the earliest signs of glial tumor initiation and progression. Methods: In order to address the clinical utility of functional imaging in radiation therapy 3-D treatment planning, we compared tumor target volume definitions and overall dosimetry in patients either undergoing co-registration of conventional Gadolinium-enhanced MRI, or co-registration of functional imaging modalities, prior to radiation therapy 3-D treatment planning. Fourteen patients were planned using 3-D radiation therapy treatment planning, either with or without inclusion of data on functional imaging. All patients received proton beam, as well as megavoltage x-ray radiation therapy, with the ratio of photon:proton optimized to the individual clinical case at hand. Both PET FDG and f MRI scans were obtained postoperatively pre-radiation, during radiation therapy, one month following completion of radiation therapy, and at three month follow-up intervals. Dose volume histograms were constructed in order to assess dose optimization, not only with respect to tumor, but also with respect to normal tissue tolerance (e.g., motor strip, dominant speech area, brainstem, optic nerves). Results: In 5 of 14 cases, functional imaging modalities, as compared with conventional MRI and CT, contributed additional information that was useful in radiation therapy treatment planning. In general, both fMRI rCBV and PET FDG uptake decreased during the course of radiation therapy. In 1 patient, however, fMRI rCBV

Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

DEFF Research Database (Denmark)

Rostrup, Egill; Larsson, H B; Toft, P B

1996-01-01

PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... in cerebral hemodynamics than noncontrast-enhanced imaging. The results of the deconvolution analysis suggested that perfusion calculation by conventional tracer kinetic methods may be impracticable because of nonlinear effects in contrast-enhanced MR imaging....

Differentiating between Glioblastoma and Primary CNS Lymphoma Using Combined Whole-tumor Histogram Analysis of the Normalized Cerebral Blood Volume and the Apparent Diffusion Coefficient.

Science.gov (United States)

Bao, Shixing; Watanabe, Yoshiyuki; Takahashi, Hiroto; Tanaka, Hisashi; Arisawa, Atsuko; Matsuo, Chisato; Wu, Rongli; Fujimoto, Yasunori; Tomiyama, Noriyuki

2018-05-31

This study aimed to determine whether whole-tumor histogram analysis of normalized cerebral blood volume (nCBV) and apparent diffusion coefficient (ADC) for contrast-enhancing lesions can be used to differentiate between glioblastoma (GBM) and primary central nervous system lymphoma (PCNSL). From 20 patients, 9 with PCNSL and 11 with GBM without any hemorrhagic lesions, underwent MRI, including diffusion-weighted imaging and dynamic susceptibility contrast perfusion-weighted imaging before surgery. Histogram analysis of nCBV and ADC from whole-tumor voxels in contrast-enhancing lesions was performed. An unpaired t-test was used to compare the mean values for each type of tumor. A multivariate logistic regression model (LRM) was performed to classify GBM and PCNSL using the best parameters of ADC and nCBV. All nCBV histogram parameters of GBMs were larger than those of PCNSLs, but only average nCBV was statistically significant after Bonferroni correction. Meanwhile, ADC histogram parameters were also larger in GBM compared to those in PCNSL, but these differences were not statistically significant. According to receiver operating characteristic curve analysis, the nCBV average and ADC 25th percentile demonstrated the largest area under the curve with values of 0.869 and 0.838, respectively. The LRM combining these two parameters differentiated between GBM and PCNSL with a higher area under the curve value (Logit (P) = -21.12 + 10.00 × ADC 25th percentile (10 -3 mm 2 /s) + 5.420 × nCBV mean, P histogram analysis of nCBV and ADC combined can be a valuable objective diagnostic method for differentiating between GBM and PCNSL.

Investigation of cognitive circuits using steady-state cerebral blood volume and diffusion tensor imaging in patients with mild cognitive impairment following electrical injury

International Nuclear Information System (INIS)

Park, Chang-hyun; Seo, Cheong Hoon; Joo, So Young; Jung, Myung Hun; Jang, Soyeon; Lee, Ho Young; Ohn, Suk Hoon

2017-01-01

We utilized cerebral blood volume (CBV) magnetic resonance imaging and diffusion tensor imaging (DTI) to investigate changes in cognitive networks in patients experiencing cognitive dysfunction following electrical injury. Cognitive function was assessed across various domains, including attention, verbal memory, executive function, and language. Depressive symptoms were also evaluated. CBV maps and DTI measures were obtained from 24 patients (age, 41.8 ± 5.8 years; education, 13.3 ± 1.9 years) and 24 healthy controls (age, 42.3 ± 2.7 years; education, 14.3 ± 1.9 years). CBV maps and DTI measures were compared between patients and controls, and correlations between these measures and each cognitive assessment score were examined. Patients exhibited lower attention, verbal memory, and executive function scores than controls (all p < 0.01). Patients also exhibited higher depression scores than controls (p < 0.01), as well as a predominant increase in CBV in the cerebellar vermis relative to that of controls (height p < uncorrected 0.001, extent p < corrected 0.05). Correlation analyses revealed a strong association between executive function scores and CBV in the bilateral posterior cingulate cortex and left mammillary body in patients (height p < uncorrected 0.001, extent p < corrected 0.05). There were no significant differences in DTI measures between patients and controls. The CBV maps showed hypermetabolism in the cerebello-limbic system; DTI did not find any microstructural changes. Our results suggest that patients experiencing cognitive dysfunction following electrical injury may possess a cognitive reserve that protects against deteriorating conditions such as dementia. (orig.)

Investigation of cognitive circuits using steady-state cerebral blood volume and diffusion tensor imaging in patients with mild cognitive impairment following electrical injury

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Park, Chang-hyun [Catholic University of Korea, Department of Psychiatry, College of Medicine, Seoul (Korea, Republic of); Seo, Cheong Hoon; Joo, So Young [Hallym University College of Medicine, Department of Physical Medicine and Rehabilitation, Hangang Sacred Heart Hospital, Seoul (Korea, Republic of); Jung, Myung Hun [Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Department of Psychiatry, Dongan-gu Anyang, Gyeonggi-do (Korea, Republic of); Jang, Soyeon; Lee, Ho Young; Ohn, Suk Hoon [Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Department of Physical Medicine and Rehabilitation, Dongan-gu Anyang, Gyeonggi-do (Korea, Republic of)

2017-09-15

We utilized cerebral blood volume (CBV) magnetic resonance imaging and diffusion tensor imaging (DTI) to investigate changes in cognitive networks in patients experiencing cognitive dysfunction following electrical injury. Cognitive function was assessed across various domains, including attention, verbal memory, executive function, and language. Depressive symptoms were also evaluated. CBV maps and DTI measures were obtained from 24 patients (age, 41.8 ± 5.8 years; education, 13.3 ± 1.9 years) and 24 healthy controls (age, 42.3 ± 2.7 years; education, 14.3 ± 1.9 years). CBV maps and DTI measures were compared between patients and controls, and correlations between these measures and each cognitive assessment score were examined. Patients exhibited lower attention, verbal memory, and executive function scores than controls (all p < 0.01). Patients also exhibited higher depression scores than controls (p < 0.01), as well as a predominant increase in CBV in the cerebellar vermis relative to that of controls (height p < uncorrected 0.001, extent p < corrected 0.05). Correlation analyses revealed a strong association between executive function scores and CBV in the bilateral posterior cingulate cortex and left mammillary body in patients (height p < uncorrected 0.001, extent p < corrected 0.05). There were no significant differences in DTI measures between patients and controls. The CBV maps showed hypermetabolism in the cerebello-limbic system; DTI did not find any microstructural changes. Our results suggest that patients experiencing cognitive dysfunction following electrical injury may possess a cognitive reserve that protects against deteriorating conditions such as dementia. (orig.)

Reliability of perfusion MR imaging in symptomatic carotid occlusive disease. Cerebral blood volume, mean transit time and time-to-peak

International Nuclear Information System (INIS)

Kim, J.H.; Lee, E.J.; Lee, S.J.; Choi, N.C.; Lim, B.H.; Shin, T.

2002-01-01

Purpose: Perfusion MR imaging offers an easy quantitative evaluation of relative regional cerebral blood volume (rrCBV), relative mean transit time (rMTT) and time-to-peak (TTP). The purpose of this study was to investigate the reliability of these parameters in assessing the hemodynamic disturbance of carotid occlusive disease in comparison with normative data. Material and Methods: Dynamic contrast-enhanced T2*-weighted perfusion MR imaging was performed in 19 patients with symptomatic unilateral internal carotid artery occlusion and 20 control subjects. The three parameters were calculated from the concentration-time curve fitted by gamma-variate function. Lesion-to-contralateral ratios of each parameter were compared between patients and control subjects. Results: Mean±SD of rrCBV, rMTT and TTP ratios of patients were 1.089±0.118, 1.054±0.031 and 1.062±0.039, respectively, and those of control subjects were 1.002±0.045, 1.000±0.006, 1.001±0.006, respectively. The rMTT and TTP ratios of all patients were greater than 2SDs of control data, whereas in only 6 patients (32%), rrCBV ratios were greater than 2SDs of control data. The three parameter ratios of the patients were significantly high compared with those of control subjects, respectively (p<0.01 for rrCBV ratios, p<0.0001 for rMTT ratios, and p<0.0001 for TTP ratios). Conclusion: Our results indicate that rMTT and TTP of patients, in contrast to rrCBV, are distributed in narrow ranges minimally overlapped with control data. The rMTT and TTP could be more reliable parameters than rrCBV in assessing the hemodynamic disturbance in carotid occlusive disease

Susceptibility contrast imaging of CO2-induced changes in the blood volume of the human brain

DEFF Research Database (Denmark)

Rostrup, Egill; Larsson, H B; Toft, P B

1996-01-01

PURPOSE: To investigate changes in the regional cerebral blood volume (rCBV) in human subjects during rest and hypercapnia by MR imaging, and to compare the results from contrast-enhanced and noncontrast-enhanced susceptibility-weighted imaging. MATERIAL AND METHODS: Five healthy volunteers (aged...... to be in accordance with results obtained by other methods. Noncontrast functional MR (fMR) imaging showed signal increases in gray matter, but also inconsistent changes in some white matter regions. CONCLUSION: In this experiment, contrast-enhanced imaging seemed to show a somewhat higher sensitivity towards changes...

Determinants of the renin-angiotensin-aldosterone system in cirrhosis with special emphasis on the central blood volume

DEFF Research Database (Denmark)

Møller, Søren; Bendtsen, Flemming; Henriksen, Jens H

2006-01-01

OBJECTIVE: Several studies have shown activation of the renin-angiotensin-aldosterone system (RAAS) in cirrhosis. Although the activated RAAS may have several determinants, the system is often considered a surrogate marker of effective hypovolaemia. In this study we investigated the activity...... of the RAAS and its potential determinants with special focus on the central and arterial blood volume (CBV). MATERIAL AND METHODS: Eighty-nine patients (Child class A/B/C: 19/41/29) and 32 controls were included in the study. All were given a haemodynamic examination with measurement of determinants...

Low Cerebral Blood Volume Identifies Poor Outcome in Stent Retriever Thrombectomy

International Nuclear Information System (INIS)

Protto, Sara; Pienimäki, Juha-Pekka; Seppänen, Janne; Numminen, Heikki; Sillanpää, Niko

2017-01-01

BackgroundMechanical thrombectomy (MT) is an efficient treatment of acute stroke caused by large-vessel occlusion. We evaluated the factors predicting poor clinical outcome (3-month modified Rankin Scale, mRS >2) although MT performed with modern stent retrievers.MethodsWe prospectively collected the clinical and imaging data of 105 consecutive anterior circulation stroke patients who underwent MT after multimodal CT imaging. Patients with occlusion of the internal carotid artery and/or middle cerebral artery up to the M2 segment were included. We recorded baseline clinical, procedural and imaging variables, technical outcome, 24-h imaging outcome and the clinical outcome. Differences between the groups were studied with appropriate statistical tests and binary logistic regression analysis.ResultsLow cerebral blood volume Alberta stroke program early CT score (CBV-ASPECTS) was associated with poor clinical outcome (median 7 vs. 9, p = 0.01). Lower collateral score (CS) significantly predicted poor outcome in regression modelling with CS = 0 increasing the odds of poor outcome 4.4-fold compared to CS = 3 (95% CI 1.27–15.5, p = 0.02). Lower CBV-ASPECTS significantly predicted poor clinical outcome among those with moderate or severe stroke (OR 0.82, 95% CI 0.68–1, p = 0.05) or poor collateral circulation (CS 0–1, OR 0.66, 95% CI 0.48–0.90, p = 0.009) but not among those with mild strokes or good collaterals.ConclusionsCBV-ASPECTS estimating infarct core is a significant predictor of poor clinical outcome among anterior circulation stroke patients treated with MT, especially in the setting of poor collateral circulation and/or moderate or severe stroke.

Low Cerebral Blood Volume Identifies Poor Outcome in Stent Retriever Thrombectomy

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Protto, Sara, E-mail: sara.protto@pshp.fi; Pienimäki, Juha-Pekka; Seppänen, Janne [Tampere University Hospital, Medical Imaging Center (Finland); Numminen, Heikki [Tampere University Hospital, Department of Neurology (Finland); Sillanpää, Niko [Tampere University Hospital, Medical Imaging Center (Finland)

2017-04-15

BackgroundMechanical thrombectomy (MT) is an efficient treatment of acute stroke caused by large-vessel occlusion. We evaluated the factors predicting poor clinical outcome (3-month modified Rankin Scale, mRS >2) although MT performed with modern stent retrievers.MethodsWe prospectively collected the clinical and imaging data of 105 consecutive anterior circulation stroke patients who underwent MT after multimodal CT imaging. Patients with occlusion of the internal carotid artery and/or middle cerebral artery up to the M2 segment were included. We recorded baseline clinical, procedural and imaging variables, technical outcome, 24-h imaging outcome and the clinical outcome. Differences between the groups were studied with appropriate statistical tests and binary logistic regression analysis.ResultsLow cerebral blood volume Alberta stroke program early CT score (CBV-ASPECTS) was associated with poor clinical outcome (median 7 vs. 9, p = 0.01). Lower collateral score (CS) significantly predicted poor outcome in regression modelling with CS = 0 increasing the odds of poor outcome 4.4-fold compared to CS = 3 (95% CI 1.27–15.5, p = 0.02). Lower CBV-ASPECTS significantly predicted poor clinical outcome among those with moderate or severe stroke (OR 0.82, 95% CI 0.68–1, p = 0.05) or poor collateral circulation (CS 0–1, OR 0.66, 95% CI 0.48–0.90, p = 0.009) but not among those with mild strokes or good collaterals.ConclusionsCBV-ASPECTS estimating infarct core is a significant predictor of poor clinical outcome among anterior circulation stroke patients treated with MT, especially in the setting of poor collateral circulation and/or moderate or severe stroke.

Database of normal human cerebral blood flow, cerebral blood volume, cerebral oxygen extraction fraction and cerebral metabolic rate of oxygen measured by positron emission tomography with {sup 15}O-labelled carbon dioxide or water, carbon monoxide and oxygen: a multicentre study in Japan

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Ito, Hiroshi [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Department of Nuclear Medicine and Radiology, Division of Brain Sciences, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-Machi, 980-8575, Aoba-Ku, Sendai (Japan); Kanno, Iwao [Department of Radiology and Nuclear Medicine, Akita Research Institute of Brain and Blood Vessels, Akita (Japan); Kato, Chietsugu [Department of Nuclear Medicine, Hokkaido University School of Medicine, Sapporo (Japan); Sasaki, Toshiaki [Cyclotoron Research Center, Iwate Medical University, Morioka (Japan); Ishii, Kenji [Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Tokyo (Japan); Ouchi, Yasuomi [Positron Medical Center, Hamamatsu Medical Center, Hamakita (Japan); Iida, Akihiko [Nagoya City Rehabilitation Center, Nagoya (Japan); Okazawa, Hidehiko [PET Unit, Research Institute, Shiga Medical Center, Moriyama (Japan); Hayashida, Kohei [Department of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Tsuyuguchi, Naohiro [Department of Neurosurgery, Osaka City University Medical School, Osaka (Japan); Ishii, Kazunari [Division of Imaging Research, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Kuwabara, Yasuo [Department of Radiology, Faculty of Medicine, Kyushu University, Fukuoka (Japan); Senda, Michio [Department of Image-based Medicine, Institute of Biomedical Research and Innovation, Kobe (Japan)

2004-05-01

Measurement of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO{sub 2}) by positron emission tomography (PET) with oxygen-15 labelled carbon dioxide (C{sup 15}O{sub 2}) or {sup 15}O-labelled water (H{sub 2}{sup 15}O), {sup 15}O-labelled carbon monoxide (C{sup 15}O) and {sup 15}O-labelled oxygen ({sup 15}O{sub 2}) is useful for diagnosis and treatment planning in cases of cerebrovascular disease. The measured values theoretically depend on various factors, which may differ between PET centres. This study explored the applicability of a database of {sup 15}O-PET by examining between-centre and within-centre variation in values. Eleven PET centres participated in this multicentre study; seven used the steady-state inhalation method, one used build-up inhalation and three used bolus administration of C{sup 15}O{sub 2} (or H{sub 2}{sup 15}O) and {sup 15}O{sub 2}. All used C{sup 15}O for measurement of CBV. Subjects comprised 70 healthy volunteers (43 men and 27 women; mean age 51.8{+-}15.1 years). Overall mean{+-}SD values for cerebral cortical regions were: CBF=44.4{+-}6.5 ml 100 ml{sup -1} min{sup -1}; CBV=3.8{+-}0.7 ml 100 ml{sup -1}; OEF=0.44{+-}0.06; CMRO{sub 2}=3.3{+-}0.5 ml 100 ml{sup -1} min{sup -1}. Significant between-centre variation was observed in CBV, OEF and CMRO{sub 2} by one-way analysis of variance. However, the overall inter-individual variation in CBF, CBV, OEF and CMRO{sub 2} was acceptably small. Building a database of normal cerebral haemodynamics obtained by the{sup 15}O-PET methods may be practicable. (orig.)

Functional Response of Tumor Vasculature to PaCO2: Determination of Total and Microvascular Blood Volume by MRI

Directory of Open Access Journals (Sweden)

Scott D. Packard

2003-07-01

Full Text Available In order to identify differences in functional activity, we compared the reactivity of glioma vasculature and the native cerebral vasculature to both dilate and constrict in response to altered PaCO2. Gliomas were generated by unilateral implantation of U87MGdEGFR human glioma tumor cells into the striatum of adult female athymic rats. Relative changes in total and microvascular cerebral blood volume were determined by steady state contrast agent-enhanced magnetic resonance imaging for transitions from normocarbia to hypercarbia and hypocarbia. Although hypercarbia induced a significant increase in both total and microvascular blood volume in normal brain and glioma, reactivity of glioma vasculature was significantly blunted in comparison to normal striatum; glioma total CBV increased by 0.6±0.1%/mm Hg CO2 whereas normal striatum increased by 1.5±0.2%/mm Hg CO2, (P < .0001, group t-test. Reactivity of microvascular blood volume was also significantly blunted. In contrast, hypocarbia decreased both total and microvascular blood volumes more in glioma than in normal striatum. These results indicate that cerebral blood vessels derived by tumor-directed angiogenesis do retain reactivity to CO2. Furthermore, reduced reactivity of tumor vessels to a single physiological perturbation, such as hypercarbia, should not be construed as a generalized reduction of functional activity of the tumor vascular bed.

Simultaneous assessment of cerebral blood volume and diffusion heterogeneity using hybrid IVIM and DK MR imaging: initial experience with brain tumors.

Science.gov (United States)

Wu, Wen-Chau; Yang, Shun-Chung; Chen, Ya-Fang; Tseng, Han-Min; My, Pei-Chi

2017-01-01

To investigate the feasibility of simultaneously assessing cerebral blood volume and diffusion heterogeneity using hybrid diffusion-kurtosis (DK) and intravoxel-incoherent-motion (IVIM) MR imaging. Fifteen healthy volunteers and 30 patients with histologically proven brain tumours (25 WHO grade II-IV gliomas and five metastases) were recruited. On a 3-T system, diffusion-weighted imaging was performed with six b-values ranging from 0 to 1,700 s/mm 2 . Nonlinear least-squares fitting was employed to extract diffusion coefficient (D), diffusion kurtosis coefficient (K, a measure of the degree of non-Gaussian and heterogeneous diffusion) and intravascular volume fraction (f, a measure proportional to cerebral blood volume). Repeated-measures multivariate analysis of variance and receiver operating characteristic analysis were performed to assess the ability of D/K/f in differentiating contrast-enhanced tumour from peritumoral oedema and normal-appearing white matter. Based on our imaging setting (baseline signal-to-noise ratio = 32-128), coefficient of variation was 14-20 % for K, ~6 % for D and 26-44 % for f. The indexes were able to differentiate contrast-enhanced tumour (Wilks' λ = 0.026, p DK IVIM imaging is capable of simultaneously measuring cerebral perfusion and diffusion indexes that together may improve brain tumour diagnosis. • Hybrid DK-IVIM imaging allows simultaneous measurement of K, D and f. • Combined K/D/f better demarcates contrast-enhanced tumour than they do separately. • f correlates better with contrast-leakage-corrected CBV DSC than with uncorrected CBV DSC.

The effect of blood transfusion on cerebral hemodynamics in preterm infants.

Science.gov (United States)

Koyano, Kosuke; Kusaka, Takashi; Nakamura, Shinji; Nakamura, Makoto; Konishi, Yukihiko; Miki, Takanori; Ueno, Masaki; Yasuda, Saneyuki; Okada, Hitoshi; Nishida, Tomoko; Isobe, Kenichi; Itoh, Susumu

2013-07-01

Anemia of prematurity commonly occurs in infants with very low birth weight; blood transfusion is an important treatment. However, there is no clear evidence to support the criteria currently widely used, based on blood hemoglobin (bHb) and hematocrit indices. Previous studies showed that overtransfusion or a low threshold for transfusion could induce complications or neurologic sequelae, respectively. We hypothesized that a cerebral hemodynamic index may provide an appropriate criterion for determining the need for transfusion in anemic preterm infants. We used near-infrared time-resolved spectroscopy to measure cerebral hemoglobin oxygen saturation (ScO2 ) and cerebral blood volume (CBV) before and after transfusion in 19 infants (24 measurements) with anemia of prematurity. The median gestational age was 27 weeks 0 days, median birth weight was 751 g, and median postconceptual age at transfusion was 30 weeks 4 days. bHb levels before and after transfusion (mean ± SD) were 9.3 ± 1.4 and 13.7 ± 1.3 g/dL, respectively. After transfusion, CBV significantly decreased from 2.63 ± 0.60 to 2.13 ± 0.26 mL/100 g of brain, and ScO2 significantly increased from 72.8 ± 4.3% to 74.7 ± 4.2%. After transfusion, CBV changes were significantly greater with low compared to high pretransfusion Hb levels. This reflected the physiologic response to severe anemia in premature infants, which is to increase CBV and decrease ScO2 . Therefore, CBV and ScO2 may be useful markers for determining the need for transfusion in very-low-birth-weight infants. © 2012 American Association of Blood Banks.

Influence of upper body position on middle cerebral artery blood velocity during continuous positive airway pressure breathing

DEFF Research Database (Denmark)

Højlund Rasmussen, J; Mantoni, T; Belhage, B

2007-01-01

Continuous positive airway pressure (CPAP) is a treatment modality for pulmonary oxygenation difficulties. CPAP impairs venous return to the heart and, in turn, affects cerebral blood flow (CBF) and augments cerebral blood volume (CBV). We considered that during CPAP, elevation of the upper body ...

MR vascular fingerprinting: A new approach to compute cerebral blood volume, mean vessel radius, and oxygenation maps in the human brain.

Science.gov (United States)

Christen, T; Pannetier, N A; Ni, W W; Qiu, D; Moseley, M E; Schuff, N; Zaharchuk, G

2014-04-01

In the present study, we describe a fingerprinting approach to analyze the time evolution of the MR signal and retrieve quantitative information about the microvascular network. We used a Gradient Echo Sampling of the Free Induction Decay and Spin Echo (GESFIDE) sequence and defined a fingerprint as the ratio of signals acquired pre- and post-injection of an iron-based contrast agent. We then simulated the same experiment with an advanced numerical tool that takes a virtual voxel containing blood vessels as input, then computes microscopic magnetic fields and water diffusion effects, and eventually derives the expected MR signal evolution. The parameter inputs of the simulations (cerebral blood volume [CBV], mean vessel radius [R], and blood oxygen saturation [SO2]) were varied to obtain a dictionary of all possible signal evolutions. The best fit between the observed fingerprint and the dictionary was then determined by using least square minimization. This approach was evaluated in 5 normal subjects and the results were compared to those obtained by using more conventional MR methods, steady-state contrast imaging for CBV and R and a global measure of oxygenation obtained from the superior sagittal sinus for SO2. The fingerprinting method enabled the creation of high-resolution parametric maps of the microvascular network showing expected contrast and fine details. Numerical values in gray matter (CBV=3.1±0.7%, R=12.6±2.4μm, SO2=59.5±4.7%) are consistent with literature reports and correlated with conventional MR approaches. SO2 values in white matter (53.0±4.0%) were slightly lower than expected. Numerous improvements can easily be made and the method should be useful to study brain pathologies. Copyright © 2013 Elsevier Inc. All rights reserved.

Quantification of serial changes in cerebral blood volume and metabolism in patients with recurrent glioblastoma undergoing antiangiogenic therapy

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Stadlbauer, Andreas, E-mail: andi@nmr.at [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria); Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen (Germany); Department of Radiology and Nuclear Medicine, Medical University Vienna, Währinger Gürtel 18-20, A-1097 Vienna (Austria); Pichler, Petra [First Department of Internal Medicine, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Poelten (Austria); Karl, Marianne [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria); Brandner, Sebastian [Department of Neurosurgery, University of Erlangen-Nuremberg, Schwabachanlage 6, D-91054 Erlangen (Germany); Lerch, Claudia [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria); Renner, Bertold [Institute of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nürnberg, Erlangen (Germany); Heinz, Gertraud [Institute of Medical Radiology, University Clinic of St. Pölten, Propst Führer-Straße 4, A-3100 St. Pölten (Austria)

2015-06-15

Highlights: • Antiangiogenic therapy can lead to a decreased in CBV in normal brain tissue. • Responding and pseudoresponding lesions to AAT showed a similar CBV decrease. • Cho and NAA allowed for a distinction of responding and pseudoresponding lesions. • Cr ratios are not suited for evaluation of antiangiogenic therapy response. • Responders to AAT may have an increased risk for remote progression of the GBM. - Abstract: Objectives: To evaluate the usefulness of quantitative advanced magnetic resonance imaging (MRI) methods for assessment of antiangiogenic therapy (AAT) response in recurrent glioblastoma multiforme (GBM). Methods: Eighteen patients with recurrent GBM received bevacizumab and 18 patients served as control group. Baseline MRI and two follow-up examinations were acquired every 3–5 months using dynamic susceptibility-weighted contrast (DSC) perfusion MRI and {sup 1}H-MR spectroscopic imaging ({sup 1}H-MRSI). Maps of absolute cerebral blood volume (aCBV) were coregistered with choline (Cho) and N-acetyl-aspartate (NAA) concentrations and compared to usually used relative parameters as well as controls. Results: Perfusion significantly decreased in responding and pseudoresponding GBMs but also in normal appearing brain after AAT onset. Cho and NAA concentrations were superior to Cr-ratios in lesion differentiation and showed a clear gap between responding and pseudoresponding lesions. Responders to AAT exceptionally frequently (6 out of 8 patients) showed remote GBM progression. Conclusions: Quantification of CBV reveals changes in normal brain perfusion due to AAT, which were not described so far. DSC perfusion MRI seems not to be suitable for differentiation between response and pseudoresponse to AAT. However, absolute quantification of brain metabolites may allow for distinction due to a clear gap at 6–9 months after therapy onset.

Cerebral hemodynamic changes measured by gradient-echo or spin-echo bolus tracking and its correlation to changes in ICA blood flow measured by phase-mapping MRI

DEFF Research Database (Denmark)

Marstrand, J.R.; Rostrup, Egill; Garde, Ellen

2001-01-01

Changes in cerebral blood flow (CBF) induced by Acetazolamide (ACZ) were measured using dynamic susceptibility contrast MRI (DSC-MRI) with both spin echo (SE) EPI and gradient echo (GE) EPI, and related to changes in internal carotid artery (ICA) flow measured by phase-mapping. Also examined...... was the effect of repeated bolus injections. CBF, cerebral blood volume (CBV), and mean transit time (MTT) were calculated by singular value decomposition (SVD) and by deconvolution using an exponential function as kernel. The results showed no dependency on calculation method. GE-EPI measured a significant...... increase in CBF and CBV in response to ACZ, while SE-EPI measured a significant increase in CBV and MTT. CBV and MTT change measured by SE-EPI was sensitive to previous bolus injections. There was a significant linear relation between change in CBF measured by GE-EPI and change in ICA flow. In conclusion...

Positron emission tomography in cerebrovascular disease: The relationship between regional cerebral blood flow, blood volume and oxygen metabolism

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Herold, S.

1985-03-01

Positron emission tomography in cerebrovascular disease has demonstrated the importance of the relationship between regional cerebral blood flow and the cerebral metabolic activity. In acute stroke it has been found that within the first hours after the onset of symptoms cerebral blood flow in the affected area is more depressed than cerebral oxygen utilisation. This relative preservation of oxygen utilisation results from an increase in the oxygen extraction ratio far above its normal value. However, the oxygen extraction fraction subsequently falls in the following days indicating the transition from a situation of possibly reversible ischaemia to irreversible infarction. In patients with carotid occlusive disease an increase in the oxygen extraction ratio has been observed only in very few cases. It has been shown, however, that at an earlier stage the relationship between CBF and CBV (as CBF/CBV-ratio) provides a sensitive measure of diminished perfusion pressure which could be helpful for the selection of patients for EC-IC bypass surgery. In patients with sickle cell anaemia it has been found that oxygen delivery to the brain is maintained by an increase in cerebral blood flow, whereas the oxygen extraction ratio is not increased despite the presence of a low oxygen affinity haemoglobin. Preliminary observations in classical migraine suggest an ischaemic situation during the attack.

Near-infrared spectroscopy measurement of the pulsatile component of cerebral blood flow and volume from arterial oscillations

Science.gov (United States)

Themelis, George; D'Arceuil, Helen; Diamond, Solomon G.; Thaker, Sonal; Huppert, Theodore J.; Boas, David A.

2009-01-01

We describe a near-infrared spectroscopy (NIRS) method to noninvasively measure relative changes in the pulsate components of cerebral blood flow (pCBF) and volume (pCBV) from the shape of heartbeat oscillations. We present a model that is used and data to show the feasibility of the method. We use a continuous-wave NIRS system to measure the arterial oscillations originating in the brains of piglets. Changes in the animals' CBF are induced by adding CO2 to the breathing gas. To study the influence of scalp on our measurements, comparative, invasive measurements are performed on one side of the head simultaneously with noninvasive measurements on the other side. We also did comparative measurements of CBF using a laser Doppler system to validate the results of our method. The results indicate that for sufficient source-detector separation, the signal contribution of the scalp is minimal and the measurements are representative of the cerebral hemodynamics. Moreover, good correlation between the results of the laser Doppler system and the NIRS system indicate that the presented method is capable of measuring relative changes in CBF. Preliminary results show the potential of this NIRS method to measure pCBF and pCBV relative changes in neonatal pigs. PMID:17343508

Interleaved quantitative BOLD: Combining extravascular R2' - and intravascular R2-measurements for estimation of deoxygenated blood volume and hemoglobin oxygen saturation.

Science.gov (United States)

Lee, Hyunyeol; Englund, Erin K; Wehrli, Felix W

2018-03-23

Quantitative BOLD (qBOLD), a non-invasive MRI method for assessment of hemodynamic and metabolic properties of the brain in the baseline state, provides spatial maps of deoxygenated blood volume fraction (DBV) and hemoglobin oxygen saturation (HbO 2 ) by means of an analytical model for the temporal evolution of free-induction-decay signals in the extravascular compartment. However, mutual coupling between DBV and HbO 2 in the signal model results in considerable estimation uncertainty precluding achievement of a unique set of solutions. To address this problem, we developed an interleaved qBOLD method (iqBOLD) that combines extravascular R 2 ' and intravascular R 2 mapping techniques so as to obtain prior knowledge for the two unknown parameters. To achieve these goals, asymmetric spin echo and velocity-selective spin-labeling (VSSL) modules were interleaved in a single pulse sequence. Prior to VSSL, arterial blood and CSF signals were suppressed to produce reliable estimates for cerebral venous blood volume fraction (CBV v ) as well as venous blood R 2 (to yield HbO 2 ). Parameter maps derived from the VSSL module were employed to initialize DBV and HbO 2 in the qBOLD processing. Numerical simulations and in vivo experiments at 3 T were performed to evaluate the performance of iqBOLD in comparison to the parent qBOLD method. Data obtained in eight healthy subjects yielded plausible values averaging 60.1 ± 3.3% for HbO 2 and 3.1 ± 0.5 and 2.0 ± 0.4% for DBV in gray and white matter, respectively. Furthermore, the results show that prior estimates of CBV v and HbO 2 from the VSSL component enhance the solution stability in the qBOLD processing, and thus suggest the feasibility of iqBOLD as a promising alternative to the conventional technique for quantifying neurometabolic parameters. Copyright © 2018. Published by Elsevier Inc.

The heart rate increase at the onset of high-work intensity exercise is accelerated by central blood volume loading.

Science.gov (United States)

Miyamoto, Tadayoshi; Oshima, Yoshitake; Ikuta, Komei; Kinoshita, Hiroshi

2006-01-01

Using a water immersion (WI) method, the combined effect of central blood volume (CBV) loading and work intensity on the time course of heart rate (HR) at the onset of upright dynamic exercise was investigated. Seven males cranked a cycle ergometer for 12 min using their un-immersed arms at low-, moderate- and high-work intensities, followed by a 12-min rest. For WI, the pre-exercise resting cardiac output increased by 36%, while HR decreased by 22% [from 76.8 (10.4) to 59.6 (9.8) beats/min]. WI also increased the high-frequency (HF, 0.15-0.40 Hz) component of the HR variability, suggesting an increased vagal activity. During the initial 2 min of the exercise period at low-work intensity, HR increased by 34.9 and 25.8% in the WI and control conditions, respectively. These were 117 and 73% at high-work intensity, indicating more accelerated HR with WI than the control. The plasma norepinephrine concentration increased less during high-work intensity exercise during WI, as compared to exercise during control conditions. In conclusion, the HR increase at the onset of high-work intensity exercise is accelerated by CBV loading but not at low intensity, possibly reflecting vago-sympathetic interaction and reduced baroreflex sensitivity.

No Evidence of Circumstellar Gas Surrounding Type Ia Supernova SN 2017cbv

Science.gov (United States)

Ferretti, Raphael; Amanullah, Rahman; Bulla, Mattia; Goobar, Ariel; Johansson, Joel; Lundqvist, Peter

2017-12-01

Nearby type Ia supernovae (SNe Ia), such as SN 2017cbv, are useful events to address the question of what the elusive progenitor systems of the explosions are. Hosseinzadeh et al. suggested that the early blue excess of the light curve of SN 2017cbv could be due to the supernova ejecta interacting with a non-degenerate companion star. Some SN Ia progenitor models suggest the existence of circumstellar (CS) environments in which strong outflows create low-density cavities of different radii. Matter deposited at the edges of the cavities should be at distances at which photoionization due to early ultraviolet (UV) radiation of SNe Ia causes detectable changes to the observable Na I D and Ca II H&K absorption lines. To study possible narrow absorption lines from such material, we obtained a time series of high-resolution spectra of SN 2017cbv at phases between ‑14.8 and +83 days with respect to B-band maximum, covering the time at which photoionization is predicted to occur. Both narrow Na I D and Ca II H&K are detected in all spectra, with no measurable changes between the epochs. We use photoionization models to rule out the presence of Na I and Ca II gas clouds along the line of sight of SN 2017cbv between ∼8 × 1016–2 × 1019 cm and ∼1015–1017 cm, respectively. Assuming typical abundances, the mass of a homogeneous spherical CS gas shell with radius R must be limited to {M}{{H} {{I}}}{CSM}R/{10}17[{cm}])}2 {M}ȯ . The bounds point to progenitor models that deposit little gas in their CS environment.

Cerebral blood flow and cerebral oxygen metabolism in thalamic hemorrhage

International Nuclear Information System (INIS)

Yasui, Nobuyuki; Asakura, Ken

1987-01-01

Cerebral blood flow (CBF), cerebral oxygen consumption (CMRO 2 ), oxygen extraction fraction (OEF) and cerebral blood volume (CBV) were studied in 20 cases of thalamic hemorrhage using positron CT and 15 O labeled gas steady-state inhalation method. CBF reduction was limited around the thalamus in the small sized hematoma. CBF were significantly diminished in the mean cortical, parietal, temporal, basal ganglia and thalamic area ipsilateral and cerebellar cortex contralateral to the medium sized hematoma. There was bilateral and diffuse CBF reduction in the large sized hematoma which was caused by increased intracranial pressure. CMRO 2 value were similary changed as CBF. OEF change showed within normal limit. Diffuse CBV reduction was observed in the large sized hematoma. This reduction was the result of decreased vascular bed caused by mass effect of the hematoma and hydrocephalus. Effect of surgical treatment such as ventricular drainage and hematoma evacuation were also discussed in correlation to CBF in some case using positron and single photon ECT. (author)

Reciprocal Influence of Slow Waves Extracted in Intracranial Pressure, Arterial Pressure and Cerebral Blood Velocity Signals

National Research Council Canada - National Science Library

Cervenansky, F

2001-01-01

...), and arterial blood pressure (ABP). To clarify the links, we compared two frequency methods based on coherence function to estimate the influence of ICP, ABP, and CBV on couples, respectively CBV-ABP, ICP-CBV and ICP-ABP, of slow waves...

Relationship between alternation of cerebral blood flow and formation of brain edema around the hematoma after experimental intracerebral hemorrhage

International Nuclear Information System (INIS)

Zhou Jian; Gao Peiyi; Li Xiaoguang

2005-01-01

Objective: To investigate the mechanism of brain edema formation around the hematoma and the relationship between the formation of brain edema and the changes of regional cerebral blood flow after intracerebral hemorrhage (ICH) in rats, and to provide experimental basis for the clinical treatment of ICH . Methods: Seventy male Sprague-Dawley rats were randomly divided into ICH groups and sham-operated groups. ICH was produced by microinjection of 40 ul fresh autologous blood or saline into the right caudatum. Dynamic CT perfusion imaging was performed, and the parameters of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), and mean transit time (MTT) around the hematoma were calculated respectively. Then the rats were sacrificed, and the water content, sodium, potassium, and calcium concentrations were measured respectively. The correlative study between the water content and rCBF and rCBV were carried out. Results:The gradient of perihematomal hypoperfusion was revealed on CT perfusion maps in ICH groups. The alternation of rCBF around the hematomas were fluctuated, and rCBF reduction was most pronounced at 1 hour afer ICH, then the rCBF gradually returned, reaching the peaks at 6 hours and 24 hours after ICH, respectively. In the meantime, rCBV reduction around the hematoma was most pronounced at 1 hour after ICH. Then the rCBV gradually increased, and reaching the peak at 24 hours. The water contents were gradually increased in the ipsilateral basal ganglia in the animals sacrificed at 6, 24, and 72 hours. The accumulation of water was at its peak at 24 hours, and remained in the animals sacrificed at the 72 hours. The perihemorrhagic water contents correlated significantly with rCBV surrounding hematomas, r=0.372 (one-tailed), P<0.05. Conclusion: The perihemorrhagic brain edema results from the common effects of the blood-brain-barrier disruption, cytotoxic edema, and the accumulation of osmotically active substances. The r

Cerebral blood flow and volume in sympton-free migraineurs: A SPECT study

International Nuclear Information System (INIS)

Maini, C.L.; Turco, G.L.; Castellano, G.; Podio, V.; Cornaglia, G.; Liboni, W.; Chianale, G.

1990-01-01

Both CBF and BCV were evaluated by gamma-camera SPECT in 14 patients with classic migraine, all studied while symptom-free. Nuclear data were correlated with CT and MRI. A decreased regional CBF was observed in 13 of the 14 patients. The decreased perfusion was localized in the frontal lobe in 6 patients, the temporal lobe in one, the parietal lobe in 11 and the occipital lobe in 5 patients. The parieto-occipital cortex was involved more often than the frontal cortex; the association of hypoperfusion with parieto-occipital cortex was quite high. The right parieto-occipital regions were affected more often than the left ones. Regional CBV was increased in 8 patients. There was good topographical concordance between decreased CBF and increased CBV, but the increase of CBV was in general more evident at the periphery of the hypoperfusion. It is of interest that the only patient with a normal CBF study had a pathological CBV study. Apparently, CBF derangements are very common in symptom-free patients with classic migraine, a CBF decrease being often accompanied by a CBV increase. In these patients both CT and MRI have a lower diagnostic yield than SPECT. (orig.) [de

Cerebral blood flow and volume in sympton-free migraineurs: A SPECT study

Energy Technology Data Exchange (ETDEWEB)

Maini, C.L. (Ancona Univ. (Italy). Chair of Nuclear Medicine); Turco, G.L.; Castellano, G.; Podio, V.; Cornaglia, G. (Turin Univ. (Italy). Chair of Nuclear Medicine); Liboni, W.; Chianale, G. (Turin Univ. (Italy). Dept. of Neurology)

1990-11-01

Both CBF and BCV were evaluated by gamma-camera SPECT in 14 patients with classic migraine, all studied while symptom-free. Nuclear data were correlated with CT and MRI. A decreased regional CBF was observed in 13 of the 14 patients. The decreased perfusion was localized in the frontal lobe in 6 patients, the temporal lobe in one, the parietal lobe in 11 and the occipital lobe in 5 patients. The parieto-occipital cortex was involved more often than the frontal cortex; the association of hypoperfusion with parieto-occipital cortex was quite high. The right parieto-occipital regions were affected more often than the left ones. Regional CBV was increased in 8 patients. There was good topographical concordance between decreased CBF and increased CBV, but the increase of CBV was in general more evident at the periphery of the hypoperfusion. It is of interest that the only patient with a normal CBF study had a pathological CBV study. Apparently, CBF derangements are very common in symptom-free patients with classic migraine, a CBF decrease being often accompanied by a CBV increase. In these patients both CT and MRI have a lower diagnostic yield than SPECT. (orig.).

Non Machinable Volume Calculation Method for 5-Axis Roughing Based on Faceted Models through Closed Bounded Area Evaluation

Directory of Open Access Journals (Sweden)

Kiswanto Gandjar

2017-01-01

Full Text Available The increase in the volume of rough machining on the CBV area is one of the indicators of increased efficiencyof machining process. Normally, this area is not subject to the rough machining process, so that the volume of the rest of the material is still big. With the addition of CC point and tool orientation to CBV area on a complex surface, the finishing will be faster because the volume of the excess material on this process will be reduced. This paper presents a method for volume calculation of the parts which do not allow further occurrence of the machining process, particulary for rough machining on a complex object. By comparing the total volume of raw materials and machining area volume, the volume of residual material,on which machining process cannot be done,can be determined. The volume of the total machining area has been taken into account for machiningof the CBV and non CBV areas. By using delaunay triangulation for the triangle which includes the machining and CBV areas. The volume will be calculated using Divergence(Gaussian theorem by focusing on the direction of the normal vector on each triangle. This method can be used as an alternative to selecting tothe rough machining methods which select minimum value of nonmachinable volume so that effectiveness can be achieved in the machining process.

Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

International Nuclear Information System (INIS)

Server, Andres; Nakstad, Per H.; Orheim, Tone E.D.; Graff, Bjoern A.; Josefsen, Roger; Kumar, Theresa

2011-01-01

Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region. (orig.)

Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis

Energy Technology Data Exchange (ETDEWEB)

Server, Andres; Nakstad, Per H. [Oslo University Hospital-Ullevaal, Section of Neuroradiology, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Oslo (Norway); Orheim, Tone E.D. [Oslo University Hospital, Interventional Centre, Oslo (Norway); Graff, Bjoern A. [Oslo University Hospital-Ullevaal, Department of Radiology and Nuclear Medicine, Oslo (Norway); Josefsen, Roger [Oslo University Hospital-Ullevaal, Department of Neurosurgery, Oslo (Norway); Kumar, Theresa [Oslo University Hospital-Ullevaal, Department of Pathology, Oslo (Norway)

2011-05-15

Conventional magnetic resonance (MR) imaging has limited capacity to differentiate between glioblastoma multiforme (GBM) and metastasis. The purposes of this study were: (1) to compare microvascular leakage (MVL), cerebral blood volume (CBV), and blood flow (CBF) in the distinction of metastasis from GBM using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MRI), and (2) to estimate the diagnostic accuracy of perfusion and permeability MR imaging. A prospective study of 61 patients (40 GBMs and 21 metastases) was performed at 3 T using DSC-MRI. Normalized rCBV and rCBF from tumoral (rCBVt, rCBFt), peri-enhancing region (rCBVe, rCBFe), and by dividing the value in the tumor by the value in the peri-enhancing region (rCBVt/e, rCBFt/e), as well as MVL were calculated. Hemodynamic and histopathologic variables were analyzed statistically and Spearman/Pearson correlations. Receiver operating characteristic curve analysis was performed for each of the variables. The rCBVe, rCBFe, and MVL were significantly greater in GBMs compared with those of metastases. The optimal cutoff value for differentiating GBM from metastasis was 0.80 which implies a sensitivity of 95%, a specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 97% for rCBVe ratio. We found a modest correlation between rCBVt and rCBFt ratios. MVL measurements in GBMs are significantly higher than those in metastases. Statistically, both rCBVe, rCBVt/e and rCBFe, rCBFt/e were useful in differentiating between GBMs and metastases, supporting the hypothesis that perfusion MR imaging can detect infiltration of tumor cells in the peri-enhancing region. (orig.)

Alterations of the Blood-Brain Barrier and Regional Perfusion in Tumor Development: MRI Insights from a Rat C6 Glioma Model.

Science.gov (United States)

Huhndorf, Monika; Moussavi, Amir; Kramann, Nadine; Will, Olga; Hattermann, Kirsten; Stadelmann, Christine; Jansen, Olav; Boretius, Susann

2016-01-01

Angiogenesis and anti-angiogenetic medications play an important role in progression and therapy of glioblastoma. In this context, in vivo characterization of the blood-brain-barrier and tumor vascularization may be important for individual prognosis and therapy optimization. We analyzed perfusion and capillary permeability of C6-gliomas in rats at different stages of tumor-growth by contrast enhanced MRI and dynamic susceptibility contrast (DSC) MRI at 7 Tesla. The analyses included maps of relative cerebral blood volume (CBV) and signal recovery derived from DSC data over a time period of up to 35 days after tumor cell injections. In all rats tumor progression was accompanied by temporal and spatial changes in CBV and capillary permeability. A leakage of the blood-brain barrier (slow contrast enhancement) was observed as soon as the tumor became detectable on T2-weighted images. Interestingly, areas of strong capillary permeability (fast signal enhancement) were predominantly localized in the center of the tumor. In contrast, the tumor rim was dominated by an increased CBV and showed the highest vessel density compared to the tumor center and the contralateral hemisphere as confirmed by histology. Substantial regional differences in the tumor highlight the importance of parameter maps in contrast or in addition to region-of-interest analyses. The data vividly illustrate how MRI including contrast-enhanced and DSC-MRI may contribute to a better understanding of tumor development.

True progression versus pseudoprogression in the treatment of glioblastomas: a comparison study of normalized cerebral blood volume and apparent diffusion coefficient by histogram analysis.

Science.gov (United States)

Song, Yong Sub; Choi, Seung Hong; Park, Chul-Kee; Yi, Kyung Sik; Lee, Woong Jae; Yun, Tae Jin; Kim, Tae Min; Lee, Se-Hoon; Kim, Ji-Hoon; Sohn, Chul-Ho; Park, Sung-Hye; Kim, Il Han; Jahng, Geon-Ho; Chang, Kee-Hyun

2013-01-01

The purpose of this study was to differentiate true progression from pseudoprogression of glioblastomas treated with concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ) by using histogram analysis of apparent diffusion coefficient (ADC) and normalized cerebral blood volume (nCBV) maps. Twenty patients with histopathologically proven glioblastoma who had received CCRT with TMZ underwent perfusion-weighted imaging and diffusion-weighted imaging (b = 0, 1000 sec/mm(2)). The corresponding nCBV and ADC maps for the newly visible, entirely enhancing lesions were calculated after the completion of CCRT with TMZ. Two observers independently measured the histogram parameters of the nCBV and ADC maps. The histogram parameters between the true progression group (n = 10) and the pseudoprogression group (n = 10) were compared by use of an unpaired Student's t test and subsequent multivariable stepwise logistic regression analysis to determine the best predictors for the differential diagnosis between the two groups. Receiver operating characteristic analysis was employed to determine the best cutoff values for the histogram parameters that proved to be significant predictors for differentiating true progression from pseudoprogression. Intraclass correlation coefficient was used to determine the level of inter-observer reliability for the histogram parameters. The 5th percentile value (C5) of the cumulative ADC histograms was a significant predictor for the differential diagnosis between true progression and pseudoprogression (p = 0.044 for observer 1; p = 0.011 for observer 2). Optimal cutoff values of 892 × 10(-6) mm(2)/sec for observer 1 and 907 × 10(-6) mm(2)/sec for observer 2 could help differentiate between the two groups with a sensitivity of 90% and 80%, respectively, a specificity of 90% and 80%, respectively, and an area under the curve of 0.880 and 0.840, respectively. There was no other significant differentiating parameter on the nCBV histograms. Inter

Cerebral blood flow and oxygen metabolism in senile dementia of Alzheimer's type and vascular dementia with deep white matter changes

International Nuclear Information System (INIS)

Tohgi, H.; Yonezawa, H.; Takahashi, S.; Sato, N.; Kato, E.; Kudo, M.; Hatano, K.; Sasaki, T.

1998-01-01

Regional cerebral blood flow (rCBF), cerebral metabolic rate of oxygen (rCMRO 2 ), oxygen extraction fraction (rOEF), and cerebral blood volume (rCBV) were investigated using positron emission tomography (PET) in 16 patients with senile dementia of Alzheimer's type (SDAT), and compared with those of 6 nondemented and 3 demented patients with deep white matter high signal (DWMH) on T2-weighted MRI and 6 controls. rCBF, rCMRO 2 and rCBV were determined using C 15 O 2 , 15 O 2 and C 15 O, respectively. rCBF and CMRO 2 were significantly decreased in the frontal, parietal and temporal cortex (P 2 was significantly reduced in only the frontal and temporal cortex of demented patients (P < 0.05). rOEF was significantly increased in the parietal cortex of patients with SDAT and in the white matter of patients with SDAT or DWMH (P < 0.05), and the increase in the frontal white matter significantly paralleled the progression of dementia in patients with SDAT (P < 0.05). rCBV was significantly decreased in the parietal and temporal cortex of patients with SDAT (P < 0.05), but not in any areas of those with DWMH. (orig.)

Blood volume studies

International Nuclear Information System (INIS)

Lewis, S.M.; Yin, J.A.L.

1986-01-01

The use of dilution analysis with such radioisotopes as 51 Cr, 32 P, sup(99m)Tc and sup(113m)In for measuring red cell volume is reviewed briefly. The use of 125 I and 131 I for plasma volume studies is also considered and the subsequent determination of total blood volume discussed, together with the role of the splenic red cell volume. Substantial bibliography. (UK)

Hemodynamics in the cerebral cortex and basal ganglia

International Nuclear Information System (INIS)

Yamaguchi, Shinya; Fukuyama, Hidenao; Yamauchi, Hiroshi; Kimura, Jun

1991-01-01

We examined ten healthy volunteers using positron emission tomography (PET) in order to elucidate regional changes and correlations in the cerebral circulation and oxygen metabolism. We also studied eight lacunar stroke patients so as to disclose the influences of vascular risk factors and aging on the cerebral blood flow and metabolism. We can conclude from our result as follows: (1) Cerebral blood volume (CBV) was minimum in the basal ganglia and cerebral blood flow (CBF)/CBV ratio was higher than that of cerebral cortex in healthy volunteers; (2) CBF of gray matter in healthy volunteers correlated with CBV and cerebral metabolic rate of oxygen where oxygen extraction fraction inversely correlated with CBF, CBV, and CBF/CBV; and (3) the basal ganglia CBF/CBV ratio in lacunar stroke patients was lower than that of healthy volunteers. These findings suggested that the perfusion pressure in the basal ganglia was so high in the normal condition than the angionecrosis or occlusion in the perforating arteries would be induced, especially in the aged and hypertensive patients. (author)

Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor

Energy Technology Data Exchange (ETDEWEB)

Hosseinzadeh, Griffin; Howell, D. Andrew; McCully, Curtis; Arcavi, Iair [Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Goleta, CA 93117-5575 (United States); Sand, David J.; Tartaglia, Leonardo [Department of Astronomy/Steward Observatory, 933 North Cherry Avenue, Room N204, Tucson, AZ 85721-0065 (United States); Valenti, Stefano; Bostroem, K. Azalee [Department of Physics, University of California, 1 Shields Avenue, Davis, CA 95616-5270 (United States); Brown, Peter [Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843-4242 (United States); Kasen, Daniel [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720-8169 (United States); Hsiao, Eric Y.; Davis, Scott; Shahbandeh, Melissa [Department of Physics, Florida State University, 77 Chieftain Way, Tallahassee, FL 32306-4350 (United States); Stritzinger, Maximilian D., E-mail: griffin@lco.global [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark)

2017-08-20

We present very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light curve is unique in that it has a blue bump during the first five days of observations in the U , B , and g bands, which is clearly resolved given our photometric cadence of 5.7 hr during that time span. We model the light curve as the combination of early shocking of the supernova ejecta against a nondegenerate companion star plus a standard SN Ia component. Our best-fit model suggests the presence of a subgiant star 56 R {sub ☉} from the exploding white dwarf, although this number is highly model-dependent. While this model matches the optical light curve well, it overpredicts the observed flux in the ultraviolet bands. This may indicate that the shock is not a blackbody, perhaps because of line blanketing in the UV. Alternatively, it could point to another physical explanation for the optical blue bump, such as interaction with circumstellar material or an unusual nickel distribution. Early optical spectra of SN 2017cbv show strong carbon (C ii λ 6580) absorption up through day −13 with respect to maximum light, suggesting that the progenitor system contains a significant amount of unburned material. These early results on SN 2017cbv illustrate the power of early discovery and intense follow-up of nearby supernovae to resolve standing questions about the progenitor systems and explosion mechanisms of SNe Ia.

Early Blue Excess from the Type Ia Supernova 2017cbv and Implications for Its Progenitor

International Nuclear Information System (INIS)

Hosseinzadeh, Griffin; Howell, D. Andrew; McCully, Curtis; Arcavi, Iair; Sand, David J.; Tartaglia, Leonardo; Valenti, Stefano; Bostroem, K. Azalee; Brown, Peter; Kasen, Daniel; Hsiao, Eric Y.; Davis, Scott; Shahbandeh, Melissa; Stritzinger, Maximilian D.

2017-01-01

We present very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light curve is unique in that it has a blue bump during the first five days of observations in the U , B , and g bands, which is clearly resolved given our photometric cadence of 5.7 hr during that time span. We model the light curve as the combination of early shocking of the supernova ejecta against a nondegenerate companion star plus a standard SN Ia component. Our best-fit model suggests the presence of a subgiant star 56 R _☉ from the exploding white dwarf, although this number is highly model-dependent. While this model matches the optical light curve well, it overpredicts the observed flux in the ultraviolet bands. This may indicate that the shock is not a blackbody, perhaps because of line blanketing in the UV. Alternatively, it could point to another physical explanation for the optical blue bump, such as interaction with circumstellar material or an unusual nickel distribution. Early optical spectra of SN 2017cbv show strong carbon (C ii λ 6580) absorption up through day −13 with respect to maximum light, suggesting that the progenitor system contains a significant amount of unburned material. These early results on SN 2017cbv illustrate the power of early discovery and intense follow-up of nearby supernovae to resolve standing questions about the progenitor systems and explosion mechanisms of SNe Ia.

The effects of superimposed tilt and lower body negative pressure on anterior and posterior cerebral circulations.

Science.gov (United States)

Tymko, Michael M; Rickards, Caroline A; Skow, Rachel J; Ingram-Cotton, Nathan C; Howatt, Michael K; Day, Trevor A

2016-09-01

Steady-state tilt has no effect on cerebrovascular reactivity to increases in the partial pressure of end-tidal carbon dioxide (PETCO2). However, the anterior and posterior cerebral circulations may respond differently to a variety of stimuli that alter central blood volume, including lower body negative pressure (LBNP). Little is known about the superimposed effects of head-up tilt (HUT; decreased central blood volume and intracranial pressure) and head-down tilt (HDT; increased central blood volume and intracranial pressure), and LBNP on cerebral blood flow (CBF) responses. We hypothesized that (a) cerebral blood velocity (CBV; an index of CBF) responses during LBNP would not change with HUT and HDT, and (b) CBV in the anterior cerebral circulation would decrease to a greater extent compared to posterior CBV during LBNP when controlling PETCO2 In 13 male participants, we measured CBV in the anterior (middle cerebral artery, MCAv) and posterior (posterior cerebral artery, PCAv) cerebral circulations using transcranial Doppler ultrasound during LBNP stress (-50 mmHg) in three body positions (45°HUT, supine, 45°HDT). PETCO2 was measured continuously and maintained at constant levels during LBNP through coached breathing. Our main findings were that (a) steady-state tilt had no effect on CBV responses during LBNP in both the MCA (P = 0.077) and PCA (P = 0.583), and (b) despite controlling for PETCO2, both the MCAv and PCAv decreased by the same magnitude during LBNP in HUT (P = 0.348), supine (P = 0.694), and HDT (P = 0.407). Here, we demonstrate that there are no differences in anterior and posterior circulations in response to LBNP in different body positions. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

International Nuclear Information System (INIS)

Kuroda, Satoshi; Sakuragi, Mitsugi; Motomiya, Mineo; Nakagawa, Tango; Mitsumori, Kenji; Tsuru, Mitsuo; Takigawa, Shugo; Kamiyama, Hiroyasu; Abe, Hiroshi.

1990-01-01

To evaluate the efficacy of tests for selecting patients with hemodynamic compromise, measurement of cerebral blood volume (CBV) with 99m Tc-RBC single photon emission computed tomography (SPECT) was performed in thirteen patients with occlusive cerebrovascular disease, and was compared with results obtained by 133 Xe SPECT and acetazolamide (Diamox) test. All patients in our study suffered TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery, although plain CT scan or MRI revealed no or, if any, only localized infarcted lesions. Regional cerebral blood volume (rCBV) was measured with 99m Tc-RBC SPECT and regional cerebral blood flow (rCBF) was measured with 133 Xe SPECT before and after intravenous injection of 10 - 12 mg/kg acetazolamide (Diamox). Our results suggest that the ipsilateral rCBV/rCBF (mean transit time) is a more sensitive index of the cerebral perfusion reserve than the use of only rCBV or rCBF of the ipsilateral hemisphere. Also, the ipsilateral rCBV/rCBF is significantly correlated (r= -0.72) with the Diamox reactivity of rCBF, which is considered to represent the cerebral vasodilatory capacity in patients with chronic cerebral ischemia. Postoperative SPECT study revealed remarkable improvement of ipsilateral rCBV/rCBF and Diamox reactivity in four patients who underwent EC/IC bypass surgery to improve the hemodynamic compromise. In conclusion, our results suggest that the measurement of rCBV/rCBF with 133 Xe SPECT and 99m Tc-RBC SPECT is useful for detecting the hemodynamic compromise in patients with occlusive cerebrovascular disease. (author)

Estimation of lung volume and pulmonary blood volume from radioisotopic images

International Nuclear Information System (INIS)

Kanazawa, Minoru

1989-01-01

Lung volume and pulmonary blood volume in man were estimated from the radioisotopic image using single photon emission computed tomography (SPECT). Six healthy volunteers were studied in a supine position with normal and altered lung volumes by applying continuous negative body-surface pressure (CNP) and by positive end-expiratory pressure (PEEP). 99m Tc labeled human serum albumin was administered as an aerosol to image the lungs. The CNP caused the diaphragm to be lowered and it increased the mean lung tissue volume obtained by SPECT from 3.09±0.49 l for baseline to 3.67±0.62 l for 10 cmH 2 O (p 2 O (p 2 O), respectively. The PEEP also increased the lung tissue volume to 3.68±0.68 l for 10 cmH 2 O as compared with the baseline (p 2 O PEEP. The lung tissue volume obtained by SPECT showed a positive correlation with functional residual capacity measured by the He dilution method (r=0.91, p 99m Tc-labeled red blood cells. The L/H ratio decreased after either the CNP or PEEP, suggesting a decrease in the blood volume per unit lung volume. However, it was suggested that the total pulmonary blood volume increased slightly either on the CNP (+7.4% for 10 cmH 2 O, p 2 O,p<0.05) when we extrapolated the L/H ratio to the whole lungs by multiplying the lung tissue volume obtained by SPECT. We concluded that SPECT could offer access to the estimation of lung volume and pulmonary blood volume in vivo. (author)

Peripheral blood volume influenced by various external factors

Energy Technology Data Exchange (ETDEWEB)

Ittner, A; Scheibe, J; Stoll, W [Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Bereich Medizin

1982-01-01

The dependence of the peripheral blood volume upon various exogenous factors was studied in male sports students using /sup 113m/InCl. The results obtained revealed that whole-body exertions and local muscular activity produce an increase of the blood volume in the lower extremities associated with increased blood circulation. The passive measures applied caused also an increase of the blood volume, but not in all of the subjects examined. Isometric concentrations led to a highly significant reduction of the peripheral blood volume. The scintigraphic method for the visualization of the blood volume in peripheral regions of the body can be regarded as suitable for the study of hemodynamics and for the substantiation of the efficiency of measures promoting restoration.

Reduced central blood volume in cirrhosis

DEFF Research Database (Denmark)

Bendtsen, F; Henriksen, Jens Henrik Sahl; Sørensen, T I

1989-01-01

than 0.0001). The lowest values (18 ml/kg) were found in patients with gross ascites and a reduced systemic vascular resistance. In patients with cirrhosis central blood volume was inversely correlated to the hepatic venous pressure gradient (r = -0.41, p less than 0.01), and the total blood volume...... was inversely correlated to the systemic vascular resistance (r = -0.49, p less than 0.001), the latter being significantly reduced in the patient group. Patients with cirrhosis apparently are unable to maintain a normal central blood volume. This may be due to arteriolar vasodilation, portosystemic collateral...

Critical evaluation of blood volume measurements during hemodialysis.

Science.gov (United States)

Dasselaar, Judith J; van der Sande, Frank M; Franssen, Casper F M

2012-01-01

Devices that continuously measure relative blood volume (RBV) changes during hemodialysis (HD) are increasingly used for the prevention of dialysis hypotension and fine-tuning of dry weight. However, RBV measurements are subject to various limitations. First, RBV devices provide information on relative blood volume changes but not on absolute blood volume. Since blood volume varies with the hydration status, identical reductions of RBV may result in very different absolute blood volumes at the end of HD. Second, RBV changes underestimate the change of total blood volume due to translocation of lower-hematocrit blood from the microcirculation to the central circulation. Third, changes in posture before and during HD, food intake, exercise, and administration of intravenous fluids may influence the validity of the RBV measurement. Fourth, results obtained by various RBV devices show large interdevice differences. Finally, although a fall in blood volume is an important factor in dialysis hypotension, frank dialysis hypotension only occurs when the cardiovascular compensatory mechanisms can no longer compensate for the reduction in blood volume. Therefore, the dialysis staff should not exclusively focus on RBV, but also search for opportunities in the dialysis prescription to facilitate cardiovascular compensatory mechanisms, e.g. by lowering dialysate temperature. In the opinion of the authors, routine RBV monitoring should be used with caution until the major conceptual and methodological problems that are inherent to the indirect RBV estimation are clarified. Copyright © 2012 S. Karger AG, Basel.

Tissue hepatic blood volume and liver function

International Nuclear Information System (INIS)

Masuyama, Mamoru

1997-01-01

Positron emission tomography (PET) scan has an advantage that it can measure regional organ blood flow and volume not only quantitatively but also non-invasively. In order to estimate the liver function, tissue hepatic blood volume was measured using C 15 O inhalation in conjunction with positron emission tomography. PET scans of the liver were performed after the single breath inhalation of 20 mCi of high specific activity 15 O-labeled carbon monoxide in 105 patients which were classified 3 groups; normal, chronic hepatitis, and cirrhosis. They consist of 61, 14, and 30 patients, respectively. Significant differences between normal and cirrhotic patients were noted in tissue hepatic blood volume (mean 20.4, 18.2, 16.0 ml/100 g, respectively). Tissue hepatic blood volume (tHBV) correlated with the reaction of the peripheral reticuloendothelial compartment and protein synthesis, because there was a potent correlation between tHBV and hepatic fibrosis. In normal livers, we were able to demonstrate significant differences in tissue hepatic blood volume among liver segments. (author)

Magnetic Resonance Perfusion Imaging in Malformations of Cortical Development

International Nuclear Information System (INIS)

Widjaja, ED.; Wilkinson, I.D.; Griffiths, P.D.

2007-01-01

Background: Malformations of cortical development vary in neuronal maturity and level of functioning. Purpose: To characterize regional relative cerebral blood volume (rCBV) and difference in first moment transit time (TTfm) in polymicrogyria and cortical tubers using magnetic resonance (MR) perfusion imaging. Material and Methods: MR imaging and dynamic T2*-weighted MR perfusion imaging were performed in 13 patients with tuberous sclerosis complex, 10 with polymicrogyria, and 18 controls with developmental delay but no macroscopic brain abnormality. Regions of interest were placed in cortical tubers or polymicrogyric cortex and in the contralateral normal-appearing side in patients with malformations. In 'control' subjects, regions of interest were placed in the frontal and parietal lobes in both hemispheres. The rCBV and TTfm of the tuber/contralateral side (rCBVRTSC and TTFMTSC) as well as those of the polymicrogyria/contralateral side (rCBVRPMG and TTFMPMG) were assessed. The right-to-left asymmetry of rCBV and TTfm in the control group was also assessed (rCBVRControls and TTFMControls). Results: There was no significant asymmetry between right and left rCBV or TTfm (P>0.05) in controls. There was significant reduction in rCBVRTSC compared to rCBVRControls (P 0.05). There were no significant differences between rCBVRPMG and rCBVRControls (P>0.05) or TTFMPMG and TTFMControls (P>0.05). Conclusion: Our findings imply that cerebral blood volume of polymicrogyria is similar to normal cortex, but there is reduced cerebral blood volume in cortical tubers. The lower rCBV ratio of cortical tubers may be related to known differences in pathogenetic timing of the underlying abnormalities during brain development or the presence of gliosis

Effect of volume expansion on systemic hemodynamics and central and arterial blood volume in cirrhosis

DEFF Research Database (Denmark)

Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

1995-01-01

, and arterial pressure were determined before and during a volume expansion induced by infusion of a hyperosmotic galactose solution. RESULTS: During volume expansion, the central and arterial blood volume increased significantly in patients with class A and controls, whereas no significant change was found...... in patients with either class B or class C. Conversely, the noncentral blood volume increased in patients with class B and C. In both patients and controls, the cardiac output increased and the systemic vascular resistance decreased, whereas the mean arterial blood pressure did not change significantly......BACKGROUND & AIMS: Systemic vasodilatation in cirrhosis may lead to hemodynamic alterations with reduced effective blood volume and decreased arterial blood pressure. This study investigates the response of acute volume expansion on hemodynamics and regional blood volumes in patients with cirrhosis...

The peripheral blood volume influenced by various external factors

International Nuclear Information System (INIS)

Ittner, A.; Scheibe, J.; Stoll, W.

1982-01-01

The dependence of the peripheral blood volume upon various exogenous factors was studied in male sports students using /sup 113m/InCl. The results obtained revealed that whole-body exertions and local muscular activity produce an increase of the blood volume in the lower extremities associated with increased blood circulation. The passive measures applied caused also an increase of the blood volume, but not in all of the subjects examined. Isometric concentrations led to a highly significant reduction of the peripheral blood volume. The scintigraphic method for the visualization of the blood volume in peripheral regions of the body can be regarded as suitable for the study of hemodynamics and for the substantiation of the efficiency of measures promoting restoration. (author)

Relative blood volume changes underestimate total blood volume changes during hemodialysis

NARCIS (Netherlands)

Dasselaar, Judith J.; Lub-de Hooge, Marjolijn N.; Pruim, Jan; Nijnuis, Hugo; Wiersum, Anneke; de Jong, Paul E.; Huisman, Roel M.; Franssen, Casper F. M.

Background: Measurements of relative blood volume changes (ARBV) during hemodialysis (HD) are based on hemoconcentration and assume uniform mixing of erythrocytes and plasma throughout the circulation. However, whole-body hematocrit (Ht) is lower than systemic Ht. During HD, a change in the ratio

Intraoperative hemodynamic monitoring during liver transplantation: goals and devices

DEFF Research Database (Denmark)

Nissen, Peter; Frederiksen, H J; Secher, N H

2010-01-01

With the introduction of orthotopic liver transplantation (OLT) almost 40 years ago, changes in the cardiovascular system that manifest during the different phases of the operation combined, sometimes with massive hemorrhage in likely critically ill patients have been a challenge. Here hemodynamic...... monitoring of the patients during OLT is addressed with focus on maintaining the patients' central blood volume (CBV) and methods and devices that can serve that purpose are listed. It is considered that a stable CBV maintains cerebral blood flow and oxygenation and thereby the well-being of the patient......, while even a small reduction in blood pressure affects cerebral blood flow and oxygenation if it reflects a reduced CBV and thereby cardiac output. In that regard it is accepted that for the patient going through OLT cardiac output (~8 L/min-1) and also venous oxygen saturation (~85%) are larger than...

Effects of MRI Protocol Parameters, Preload Injection Dose, Fractionation Strategies, and Leakage Correction Algorithms on the Fidelity of Dynamic-Susceptibility Contrast MRI Estimates of Relative Cerebral Blood Volume in Gliomas.

Science.gov (United States)

Leu, K; Boxerman, J L; Ellingson, B M

2017-03-01

DSC perfusion MR imaging assumes that the contrast agent remains intravascular; thus, disruptions in the blood-brain barrier common in brain tumors can lead to errors in the estimation of relative CBV. Acquisition strategies, including the choice of flip angle, TE, TR, and preload dose and incubation time, along with post hoc leakage-correction algorithms, have been proposed as means for combating these leakage effects. In the current study, we used DSC-MR imaging simulations to examine the influence of these various acquisition parameters and leakage-correction strategies on the faithful estimation of CBV. DSC-MR imaging simulations were performed in 250 tumors with perfusion characteristics randomly generated from the distributions of real tumor population data, and comparison of leakage-corrected CBV was performed with a theoretic curve with no permeability. Optimal strategies were determined by protocol with the lowest mean error. The following acquisition strategies (flip angle/TE/TR and contrast dose allocation for preload and bolus) produced high CBV fidelity, as measured by the percentage difference from a hypothetic tumor with no leakage: 1) 35°/35 ms/1.5 seconds with no preload and full dose for DSC-MR imaging, 2) 35°/25 ms/1.5 seconds with ¼ dose preload and ¾ dose bolus, 3) 60°/35 ms/2.0 seconds with ½ dose preload and ½ dose bolus, and 4) 60°/35 ms/1.0 second with 1 dose preload and 1 dose bolus. Results suggest that a variety of strategies can yield similarly high fidelity in CBV estimation, namely those that balance T1- and T2*-relaxation effects due to contrast agent extravasation. © 2017 by American Journal of Neuroradiology.

Application of dynamic susceptibility contrast-enhanced perfusion in temporal lobe epilepsy

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Xing, Wu; Wang, Xiaoyi; Xie, Fangfang; Liao, Weihua [Dept. of Radiology, Xiangya Hospital of Central South Univ., Changsha (China)], e-mail: doctoring@sina.com

2013-02-15

Background: Accurately locatithe epileptogenic focus in temporal lobe epilepsy (TLE) is important in clinical practice. Single-photon emission computed tomography (SPECT) and positron-emission tomography (PET) have been widely used in the lateralization of TLE, but both have limitations. Magnetic resonance perfusion imaging can accurately and reliably reflect differences in cerebral blood flow and volume. Purpose: To investigate the diagnostic value of dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) in the lateralization of the epileptogenic focus in TLE. Material and Methods: Conventional MRI and DSC-MRI scanning was performed in 20 interictal cases of TLE and 20 healthy volunteers. The relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of the bilateral mesial temporal lobes of the TLE cases and healthy control groups were calculated. The differences in the perfusion asymmetry indices (AIs), derived from the rCBV and rCBF of the bilateral mesial temporal lobes, were pared between the two groups. Results: In the control group, there were no statistically significant differences between the left and right sides in terms of rCBV (left 1.55 {+-} 0.32, right 1.57 {+-} 0.28) or rCBF (left 99.00 {+-} 24.61, right 100.38 {+-} 23.46) of the bilateral mesial temporal lobes. However, in the case group the ipsilateral rCBV and rCBF values (1.75 {+-} 0.64 and 96.35 {+-} 22.63, respectively) were markedly lower than those of the contralateral side (2.01 {+-} 0.79 and 108.56 {+-} 26.92; P < 0.05). Both the AI of the rCBV (AIrCBV; 13.03 {+-} 10.33) and the AI of the rCBF (AIrCBF; 11.24 {+-} 8.70) of the case group were significantly higher than that of the control group (AIrCBV 5.55 {+-} 3.74, AIrCBF 5.12 {+-} 3.48; P < 0.05). The epileptogenic foci of nine patients were correctly lateralized using the 95th percentile of the AIrCBV and AIrCBF of the control group as the normal upper limits. Conclusion: In

Determination of blood volume by pulse CO-oximetry

International Nuclear Information System (INIS)

Lalande, S; Kelsey, J W; Joyner, M J; Johnson, B D

2012-01-01

The objective of this study was to determine whether changes in carboxyhaemoglobin (COHb) saturation following carbon monoxide (CO) rebreathing can be accurately detected by pulse CO-oximetry in order to determine blood volume. Noninvasive measurements of carboxyhaemoglobin saturation (SpCO) were continuously monitored by pulse CO-oximetry before, during and following 2 min of CO rebreathing. Reproducibility and accuracy of noninvasive blood volume measurements were determined in 16 healthy non-smoking individuals (15 males, age: 28 ± 2 years, body mass index: 25.4 ± 0.6 kg m −2 ) through comparison with blood volume measurements calculated from invasive measurements of COHb saturation. The coefficient of variation for noninvasive blood volume measurements performed on separate days was 15.1% which decreases to 9.1% when measurements were performed on the same day. Changes in COHb saturation and SpCO following CO rebreathing were strongly correlated (r = 0.90, p < 0.01), resulting in a significant correlation between invasive and noninvasive blood volume measurements (r = 0.83, p = 0.02). Changes in SpCO following CO rebreathing can be accurately detected by pulse CO-oximetry, which could potentially provide a simplified, convenient and reproducible method to rapidly determine blood volume in healthy individuals

Post-mortem virtual estimation of free abdominal blood volume

International Nuclear Information System (INIS)

Ampanozi, Garyfalia; Hatch, Gary M.; Ruder, Thomas D.; Flach, Patricia M.; Germerott, Tanja; Thali, Michael J.; Ebert, Lars C.

2012-01-01

Purpose: The purpose of this retrospective study was to examine the reliability of virtually estimated abdominal blood volume using segmentation from postmortem computed tomography (PMCT) data. Materials and methods: Twenty-one cases with free abdominal blood were investigated by PMCT and autopsy. The volume of the blood was estimated using a manual segmentation technique (Amira, Visage Imaging, Germany) and the results were compared to autopsy data. Six of 21 cases had undergone additional post-mortem computed tomographic angiography (PMCTA). Results: The virtually estimated abdominal blood volumes did not differ significantly from those measured at autopsy. Additional PMCTA did not bias data significantly. Conclusion: Virtual estimation of abdominal blood volume is a reliable technique. The virtual blood volume estimation is a useful tool to deliver additional information in cases where autopsy is not performed or in cases where a postmortem angiography is performed

Magnetic Resonance Perfusion Imaging in Malformations of Cortical Development

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Widjaja, ED.; Wilkinson, I.D.; Griffiths, P.D. [Academic Section of Radiolog y, Univ. of Sheffield, Sheffield (United Kingdom)

2007-10-15

Background: Malformations of cortical development vary in neuronal maturity and level of functioning. Purpose: To characterize regional relative cerebral blood volume (rCBV) and difference in first moment transit time (TTfm) in polymicrogyria and cortical tubers using magnetic resonance (MR) perfusion imaging. Material and Methods: MR imaging and dynamic T2*-weighted MR perfusion imaging were performed in 13 patients with tuberous sclerosis complex, 10 with polymicrogyria, and 18 controls with developmental delay but no macroscopic brain abnormality. Regions of interest were placed in cortical tubers or polymicrogyric cortex and in the contralateral normal-appearing side in patients with malformations. In 'control' subjects, regions of interest were placed in the frontal and parietal lobes in both hemispheres. The rCBV and TTfm of the tuber/contralateral side (rCBVRTSC and TTFMTSC) as well as those of the polymicrogyria/contralateral side (rCBVRPMG and TTFMPMG) were assessed. The right-to-left asymmetry of rCBV and TTfm in the control group was also assessed (rCBVRControls and TTFMControls). Results: There was no significant asymmetry between right and left rCBV or TTfm (P>0.05) in controls. There was significant reduction in rCBVRTSC compared to rCBVRControls (P<0.05), but no significant difference in TTFMTSC compared to TTFMControls (P>0.05). There were no significant differences between rCBVRPMG and rCBVRControls (P>0.05) or TTFMPMG and TTFMControls (P>0.05). Conclusion: Our findings imply that cerebral blood volume of polymicrogyria is similar to normal cortex, but there is reduced cerebral blood volume in cortical tubers. The lower rCBV ratio of cortical tubers may be related to known differences in pathogenetic timing of the underlying abnormalities during brain development or the presence of gliosis.

The role of perfusion computed tomography in the prediction of cerebral hyperperfusion syndrome.

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Chien Hung Chang

Full Text Available Hyperperfusion syndrome (HPS following carotid angioplasty with stenting (CAS is associated with significant morbidity and mortality. At present, there are no reliable parameters to predict HPS. The aim of this study was to clarify whether perfusion computed tomography (CT is a feasible and reliable tool in predicting HPS after CAS.We performed a retrospective case-control study of 54 patients (11 HPS patients and 43 non-HPS with unilateral severe stenosis of the carotid artery who underwent CAS. We compared the prevalence of vascular risk factors and perfusion CT parameters including regional cerebral blood volume (rCBV, regional cerebral blood flow (rCBF, and time to peak (TTP within seven days prior to CAS. Demographic information, risk factors for atherosclerosis, and perfusion CT parameters were evaluated by multivariable logistic regression analysis. The rCBV index was calculated as [(ipsilateral rCBV - contralateral rCBV/contralateral rCBV], and indices of rCBF and TTP were similarly calculated. We found that eleven patients had HPS, including five with intracranial hemorrhages (ICHs of whom three died. After a comparison with non-HPS control subjects, independent predictors of HPS included the severity of ipsilateral carotid artery stenosis, 3-hour mean systolic blood pressure (3 h SBP after CAS, pre-stenting rCBV index >0.15 and TTP index >0.22.The combination of severe ipsilateral carotid stenosis, 3 h SBP after CAS, rCBV index and TTP index provides a potential screening tool for predicting HPS in patients with unilateral carotid stenosis receiving CAS. In addition, adequate management of post-stenting blood pressure is the most important treatable factor in preventing HPS in these high risk patients.

The relationship between cerebral blood flow and volume in humans

DEFF Research Database (Denmark)

Rostrup, Egill; Knudsen, Gitte M; Law, Ian

2005-01-01

intersubject variability, the goodness of fit for linear and nonlinear models were not significantly different. The results of the study are applied to a numerical estimation of regional brain deoxy-haemoglobin content. Independently of the choice of model for the rCBV vs. rCBF relationship, a nonlinear deoxy...

Blood flow and blood volume in a transplanted rat fibrosarcoma

International Nuclear Information System (INIS)

Tozer, G.M.; Morris, C.C.

1990-01-01

Blood flow measurements following i.v. infusion of iodi-antipyrine labelled with 14 C ( 14 C-IAP) and blood volume measurements following i.v. injection of 125 I human serum albumin and 51 Cr-labelled red blood cells were made in a transplanted rat fibrosarcoma for comparison with various normal tissues. The tumour-blood partition co-efficient for 14 C-IAP w as found to be 0.79 ± 0.07 which is similar to most of the normal tissues studied. The solubility of 14 C-IAP in plasma was found to be higher than that in whole blood. Blood flow to tumours 3 was found to be 17.9 ± 4.0 ml blood 100 g tissue -1 xmin -1 . These values were considered to be primarily measurements of nutritive flow. Blood in the tumours was found to occupy around 1% of the tissue space which was similar to that found for normal muscle and skin. There was no direct correlation between % blood volume and blood flow for the different tissues studied. Th haematocrit of blood contained in tumour tissue was calculated to be significantly lower than that of blood contained in the normal tissues. It was suspected that permeability of tumour blood vessel walls to 125 I-HSA could have accounted for this difference. (author). 41 refs.; 2 figs.; 3 tabs

Regional cerebral blood flow and oxygen metabolism in normal pressure hydrocephalus after subarachnoid hemorrhage

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Ishikawa, Masatsune; Kikuchi, Haruhiko; Taki, Waro; Kobayashi, Akira; Nishizawa, Sadahiko; Yonekura, Yoshiharu; Konishi, Junji [Kyoto Univ. (Japan). Faculty of Medicine

1989-05-01

To clarify the pathophysiology of normal pressure hydrocephalus (NPH) after subarachnoid hemorrhage, the authors measured cerebral blood flow (CBF), cerebral oxygen metabolic rates (CMRO{sub 2}), the cerebral oxygen extraction fraction (OEF), and cerebral blood volume (CBV) in eight normal volunteers, six SAH patients with NPH, and seven patients without NPH by {sup 15}O-labeled gas and positron emission tomography (PET). In the NPH group, PET revealed a decrease in CBF in the lower regions of the cerebral cortex and a diffuse decrease in CMRO{sub 2}. The decrease in CBF in the lower frontal, temporal, and occipital cortices was significantly greater in the NPH than in the non-NPH group. Reduction of CMRO{sub 2} was also more extensive in the NPH group, and both CBF and CMRO{sub 2} were more markedly decreased in the lower frontal region. OEF was increased in all areas in both of the patient groups, but the increase was not significant in most areas. CBF, CMRO{sub 2} and OEF did not significantly differ between the non-NPH group and the normal volunteers. There was no significant difference in CBV among the three groups. These results indicate that NPH involves impairment of cerebral oxygen metabolism in the lower regions of the cerebral cortex, particularly in the lower frontal region. (author).

Measurement of regional pulmonary blood volume in patients with increased pulmonary blood flow or pulmonary arterial hypertension

International Nuclear Information System (INIS)

Wollmer, P.; Rozcovek, A.; Rhodes, C.G.; Allan, R.M.; Maseri, A.

1984-01-01

The effects of chronic increase in pulmonary blood flow and chronic pulmonary hypertension on regional pulmonary blood volume was measured in two groups of patients. One group of patients had intracardiac, left-to-right shunts without appreciable pulmonary hypertension, and the other consisted of patients with Eisenmenger's syndrome or primary pulmonary hypertension, i.e. patients with normal or reduced blood flow and severe pulmonary hypertension. A technique based on positron tomography was used to measure lung density (by transmission scanning) and regional pulmonary blood volume (after inhalation of /sup 11/CO). The distribution of pulmonary blood volume was more uniform in patients with chronic increase in pulmonary blood flow than in normal subjects. There were also indications of an absolute increase in intrapulmonary blood volume by about 15%. In patients with chronic pulmonary arterial hypertension, the distribution of pulmonary blood volume was also abnormally uniform. There was, however, no indication that overall intrapulmonary blood volume was substantially different from normal subjects. The abnormally uniform distribution of pulmonary blood volume can be explained by recruitment and/or dilatation of vascular beds. Intrapulmonary blood volume appears to be increased in patients with intracardiac, left-to-right shunts. With the development of pulmonary hypertension, intrapulmonary blood volume falls, which may be explained by reactive changes in the vasculature and/or obliteration of capillaries

Pediatric blood volumes: a one-page reference guide.

Science.gov (United States)

Smiley, J; Reitan, J

1998-10-01

At our institution, a multidisciplinary team met to work out a blood volume policy for our pediatric patients' laboratory testing. Because we are a cancer center, many of our patients are on protocols and/or are in the hospital for an extended period of time. These factors result in multiple blood draws. It is important to manage the volumes used so that we do not compromise the hematological status of our pediatric patients. The concerns of nurses and laboratory technologists were discussed and a three-tiered system was designed consisting of adult volumes, volumes for inflexibility to verify or add to the original order without resticking the patient increase at each tier. It is imperative to the overall quality of care for all patients that discretion is used when following these guidelines. When it is medically prudent to restrict the blood volumes taken from any patient, it should be done. However, when it is not medically necessary, the increased costs and potential decrease in the quality of laboratory service outweighs the desire to use smaller blood volumes.

Orthostatic leg blood volume changes assessed by near-infrared spectroscopy

DEFF Research Database (Denmark)

Truijen, J; Kim, Y S; Krediet, C T P

2012-01-01

posture, volume accumulation in small blood vessels contributes significantly to the total fluid volume accumulated in the legs. Considering that near-infrared spectroscopy (NIRS) tracks postural blood volume changes within the small blood vessels of the lower leg, we evaluated the NIRS-determined changes......-linear accumulation of blood volume in the small vessels of the leg, with an initial fast phase followed by a more gradual increase at least partly contributing to the relocation of fluid during orthostatic stress....

Cerebral hemodynamics measured with simultaneous PET and near-infrared spectroscopy in humans

DEFF Research Database (Denmark)

Rostrup, Egill; Law, Ian; Pott, Frank

2002-01-01

Near-infrared spectroscopy (NIRS) enables continuous non-invasive quantification of blood and tissue oxygenation, and may be useful for quantification of cerebral blood volume (CBV) changes. In this study, changes in cerebral oxy- and deoxyhemoglobin were compared to corresponding changes in CBF ...

Differentiating between Central Nervous System Lymphoma and High-grade Glioma Using Dynamic Susceptibility Contrast and Dynamic Contrast-enhanced MR Imaging with Histogram Analysis.

Science.gov (United States)

Murayama, Kazuhiro; Nishiyama, Yuya; Hirose, Yuichi; Abe, Masato; Ohyu, Shigeharu; Ninomiya, Ayako; Fukuba, Takashi; Katada, Kazuhiro; Toyama, Hiroshi

2018-01-10

We evaluated the diagnostic performance of histogram analysis of data from a combination of dynamic susceptibility contrast (DSC)-MRI and dynamic contrast-enhanced (DCE)-MRI for quantitative differentiation between central nervous system lymphoma (CNSL) and high-grade glioma (HGG), with the aim of identifying useful perfusion parameters as objective radiological markers for differentiating between them. Eight lesions with CNSLs and 15 with HGGs who underwent MRI examination, including DCE and DSC-MRI, were enrolled in our retrospective study. DSC-MRI provides a corrected cerebral blood volume (cCBV), and DCE-MRI provides a volume transfer coefficient (K trans ) for transfer from plasma to the extravascular extracellular space. K trans and cCBV were measured from a round region-of-interest in the slice of maximum size on the contrast-enhanced lesion. The differences in t values between CNSL and HGG for determining the most appropriate percentile of K trans and cCBV were investigated. The differences in K trans , cCBV, and K trans /cCBV between CNSL and HGG were investigated using histogram analysis. Receiver operating characteristic (ROC) analysis of K trans , cCBV, and K trans /cCBV ratio was performed. The 30 th percentile (C30) in K trans and 80 th percentile (C80) in cCBV were the most appropriate percentiles for distinguishing between CNSL and HGG from the differences in t values. CNSL showed significantly lower C80 cCBV, significantly higher C30 K trans , and significantly higher C30 K trans /C80 cCBV than those of HGG. In ROC analysis, C30 K trans /C80 cCBV had the best discriminative value for differentiating between CNSL and HGG as compared to C30 K trans or C80 cCBV. The combination of K trans by DCE-MRI and cCBV by DSC-MRI was found to reveal the characteristics of vascularity and permeability of a lesion more precisely than either K trans or cCBV alone. Histogram analysis of these vascular microenvironments enabled quantitative differentiation between

Validation and absolute quantification of MR perfusion compared with CT perfusion in patients with unilateral cerebral arterial stenosis

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Chiu, Fang-Ying, E-mail: fychiou@hotmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Kao, Yi-Hsuan, E-mail: yhkao@ym.edu.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Teng, Michael Mu Huo, E-mail: mhteng@gmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); School of Medicine, National Yang-Ming University, Taipei City, Taiwan (China); Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Chung, Hsiao-Wen, E-mail: chung@cc.ee.ntu.edu.tw [Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China); Chang, Feng-Chi, E-mail: fcchang374@gmail.com [School of Medicine, National Yang-Ming University, Taipei City, Taiwan (China); Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan (China); Cho, I-Chieh, E-mail: jessie8030@yahoo.com.tw [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China); Chen, Wen-Chun, E-mail: sky7408695@hotmail.com [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei City, Taiwan (China)

2012-12-15

Objective: The aim of the study was to assess absolute quantification of dynamic susceptibility contrast-enhanced magnetic resonance perfusion (MRP) comparing with computed tomography perfusion (CTP) in patients with unilateral stenosis. Materials and methods: We retrospectively post-processed MRP in 20 patients with unilateral occlusion or stenosis of >79% at the internal carotid artery or the middle cerebral artery (MCA). Absolute quantification of MRP was performed after applying the following techniques: cerebrospinal fluid removal, vessel removal, and automatic segmentation of brain to calculate the scaling factors to convert relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values to absolute values. For comparison between MRP and CTP, we manually deposited regions of interest in bilateral MCA territories at the level containing the body of the lateral ventricle. Results: The correlation between MRP and CTP was best for mean transit time (MTT) (r = 0.83), followed by cerebral blood flow (CBF) (r = 0.52) and cerebral blood volume (CBV) (r = 0.43). There was no significant difference between CTP and MRP for CBV, CBF, and MTT on the lesion side, the contralateral side, the lesion-contralateral differences, or the lesion-to-contralateral ratios (P > 0.05). The mean differences between MRP and CTP were as follows: CBV −0.57 mL/100 g, CBF 2.50 mL/100 g/min, and MTT −0.90 s. Conclusion: Absolute quantification of MRP is possible. Using the proposed method, measured values of MRP and CTP had acceptable linear correlation and quantitative agreement.

Validation and absolute quantification of MR perfusion compared with CT perfusion in patients with unilateral cerebral arterial stenosis

International Nuclear Information System (INIS)

Chiu, Fang-Ying; Kao, Yi-Hsuan; Teng, Michael Mu Huo; Chung, Hsiao-Wen; Chang, Feng-Chi; Cho, I-Chieh; Chen, Wen-Chun

2012-01-01

Objective: The aim of the study was to assess absolute quantification of dynamic susceptibility contrast-enhanced magnetic resonance perfusion (MRP) comparing with computed tomography perfusion (CTP) in patients with unilateral stenosis. Materials and methods: We retrospectively post-processed MRP in 20 patients with unilateral occlusion or stenosis of >79% at the internal carotid artery or the middle cerebral artery (MCA). Absolute quantification of MRP was performed after applying the following techniques: cerebrospinal fluid removal, vessel removal, and automatic segmentation of brain to calculate the scaling factors to convert relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values to absolute values. For comparison between MRP and CTP, we manually deposited regions of interest in bilateral MCA territories at the level containing the body of the lateral ventricle. Results: The correlation between MRP and CTP was best for mean transit time (MTT) (r = 0.83), followed by cerebral blood flow (CBF) (r = 0.52) and cerebral blood volume (CBV) (r = 0.43). There was no significant difference between CTP and MRP for CBV, CBF, and MTT on the lesion side, the contralateral side, the lesion-contralateral differences, or the lesion-to-contralateral ratios (P > 0.05). The mean differences between MRP and CTP were as follows: CBV −0.57 mL/100 g, CBF 2.50 mL/100 g/min, and MTT −0.90 s. Conclusion: Absolute quantification of MRP is possible. Using the proposed method, measured values of MRP and CTP had acceptable linear correlation and quantitative agreement.

Diagnostic performance of whole brain volume perfusion CT in intra-axial brain tumors: Preoperative classification accuracy and histopathologic correlation

International Nuclear Information System (INIS)

Xyda, Argyro; Haberland, Ulrike; Klotz, Ernst; Jung, Klaus; Bock, Hans Christoph; Schramm, Ramona; Knauth, Michael; Schramm, Peter

2012-01-01

Background: To evaluate the preoperative diagnostic power and classification accuracy of perfusion parameters derived from whole brain volume perfusion CT (VPCT) in patients with cerebral tumors. Methods: Sixty-three patients (31 male, 32 female; mean age 55.6 ± 13.9 years), with MRI findings suspected of cerebral lesions, underwent VPCT. Two readers independently evaluated VPCT data. Volumes of interest (VOIs) were marked circumscript around the tumor according to maximum intensity projection volumes, and then mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability Ktrans perfusion datasets. A second VOI was placed in the contra lateral cortex, as control. Correlations among perfusion values, tumor grade, cerebral hemisphere and VOIs were evaluated. Moreover, the diagnostic power of VPCT parameters, by means of positive and negative predictive value, was analyzed. Results: Our cohort included 32 high-grade gliomas WHO III/IV, 18 low-grade I/II, 6 primary cerebral lymphomas, 4 metastases and 3 tumor-like lesions. Ktrans demonstrated the highest sensitivity, specificity and positive predictive value, with a cut-off point of 2.21 mL/100 mL/min, for both the comparisons between high-grade versus low-grade and low-grade versus primary cerebral lymphomas. However, for the differentiation between high-grade and primary cerebral lymphomas, CBF and CBV proved to have 100% specificity and 100% positive predictive value, identifying preoperatively all the histopathologically proven high-grade gliomas. Conclusion: Volumetric perfusion data enable the hemodynamic assessment of the entire tumor extent and provide a method of preoperative differentiation among intra-axial cerebral tumors with promising diagnostic accuracy.

Application of dynamic susceptibility contrast-enhanced perfusion in temporal lobe epilepsy

International Nuclear Information System (INIS)

Xing, Wu; Wang, Xiaoyi; Xie, Fangfang; Liao, Weihua

2013-01-01

Background: Accurately locatithe epileptogenic focus in temporal lobe epilepsy (TLE) is important in clinical practice. Single-photon emission computed tomography (SPECT) and positron-emission tomography (PET) have been widely used in the lateralization of TLE, but both have limitations. Magnetic resonance perfusion imaging can accurately and reliably reflect differences in cerebral blood flow and volume. Purpose: To investigate the diagnostic value of dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) in the lateralization of the epileptogenic focus in TLE. Material and Methods: Conventional MRI and DSC-MRI scanning was performed in 20 interictal cases of TLE and 20 healthy volunteers. The relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of the bilateral mesial temporal lobes of the TLE cases and healthy control groups were calculated. The differences in the perfusion asymmetry indices (AIs), derived from the rCBV and rCBF of the bilateral mesial temporal lobes, were pared between the two groups. Results: In the control group, there were no statistically significant differences between the left and right sides in terms of rCBV (left 1.55 ± 0.32, right 1.57 ± 0.28) or rCBF (left 99.00 ± 24.61, right 100.38 ± 23.46) of the bilateral mesial temporal lobes. However, in the case group the ipsilateral rCBV and rCBF values (1.75 ± 0.64 and 96.35 ± 22.63, respectively) were markedly lower than those of the contralateral side (2.01 ± 0.79 and 108.56 ± 26.92; P < 0.05). Both the AI of the rCBV (AIrCBV; 13.03 ± 10.33) and the AI of the rCBF (AIrCBF; 11.24 ± 8.70) of the case group were significantly higher than that of the control group (AIrCBV 5.55 ± 3.74, AIrCBF 5.12 ± 3.48; P < 0.05). The epileptogenic foci of nine patients were correctly lateralized using the 95th percentile of the AIrCBV and AIrCBF of the control group as the normal upper limits. Conclusion: In patients with TLE interictal

The determination of blood volume in horses using stable isotope 50Cr

International Nuclear Information System (INIS)

Ito, Nobuhiko; Kunugiyama, Iwao; Tanaka, Masayoshi; Inoue, Megumi; Furukawa, Yoshinori; Hiraga, Atsushi; Yamanobe, Akira; Kubo, Katsuyoshi.

1991-01-01

A method using stable isotope 50 Cr was presented to determine equine blood volumes accurately in the field. The erythrocyte labelled with 50 Cr was injected intravenously, then small amount of blood was collected at regular intervals, and the erythrocyte volume was measured from dilution rate of 50 Cr. A blood volume was calculated from the erythrocyte volume and the packed cell volume (PCV). The present results suggested that the optimum time of collecting blood at rest was 2 h after injection of tagged blood. The red cell volumes and the total blood volumes of fifteen thoroughbred horses measured by the 50 Cr method were 46.6±9.9 and 133±17 ml/kg body weight, respectively. The mean red cell volume of stallion was larger than mare (t-test, p<0.05), and three was no significant difference in the blood volume. (author)

Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

Science.gov (United States)

Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

2013-01-01

Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%±0.43% (mean±SD) before acclimation for the experimental group, and 4.76%±0.29% after acclimation. The CBV for the control group is 3.28%±0.75%, and 3.09%±0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals.

Colloid volume loading does not mitigate decreases in central blood volume during simulated hemorrhage while heat stressed

DEFF Research Database (Denmark)

Crandall, Craig G; Wilson, Thad E; Marving, Jens

2012-01-01

attenuates the reduction in regional blood volumes during a simulated hemorrhagic challenge imposed via lower-body negative pressure (LBNP). Seven subjects underwent 30 mmHg LBNP while normothermic, during passive heat stress (increased internal temperature ~1°C), and while continuing to be heated after...... intravenous colloid volume loading (11 ml/kg). Relative changes in torso and regional blood volumes were determined by gamma camera imaging with technetium-99m labeled erythrocytes. Heat stress reduced blood volume in all regions (ranging from 7 to 16%), while subsequent volume loading returned those values...... to normothermic levels. While normothermic, LBNP reduced blood volume in all regions (torso: 22±8%; heart: 18±6%; spleen: 15±8%). During LBNP while heat stressed, the reductions in blood volume in each region were markedly greater when compared to LBNP while normothermic (torso: 73±2%; heart: 72±3%; spleen: 72...

[Blood volume for biochemistry determinations--laboratory needs and everyday practice].

Science.gov (United States)

Sztefko, Krystyna; Mamica, Katarzyna; Bugajska, Jolanta; Maziarz, Barbara; Tomasik, Przemysław

2014-01-01

Blood loss due to diagnostic phlebotomy jest a very serious problem, especially for newborn, infants and critically ill patients on intensive care units. Although single blood loss can be easily tolerated in adults, in small babies and in patients who are frequently monitored based on laboratory tests iatrogenic anaemia can occur. To evaluate the blood volume drawn for routine biochemistry tests in relation to patient age and the number of parameters requested. Blood volume drawn for routine biochemistry measurements from patients hospitalized in University Children's Hospital (N = 2980, children age from one day to 18 years) and in University Hospital (N = 859, adults, aged > 1.8 years) in Cracow has been analyzed. Blood volume was calculated based on regular tube diameter and blood heights in the tube. In case of microvettes the blood volume was 0.2 ml. Statistical analysis has been performed by using PRISM 5.0. The statistical significance was set at p nurses and doctors should include the information about current laboratory automation and methods miniaturization; 2) The amount of blood volume needed by laboratory for the requested number of tests should always be taken into account when diagnostic phlebotomy is necessary.

Determination of the blood volume of rabbits (1963)

International Nuclear Information System (INIS)

Bernard, Y.; Pierotti, Th.; Rinaldi, R.

1963-01-01

The knowledge of the ratio of the blood volume to the weight of an animal is of a great deal in various experiments. Therefore authors have decided to determine this ratio for rabbits by using chromium 51. Results show that the blood volume represents about 54.4 g per kilogram of body weight. (authors) [fr

Immersive volume rendering of blood vessels

Science.gov (United States)

Long, Gregory; Kim, Han Suk; Marsden, Alison; Bazilevs, Yuri; Schulze, Jürgen P.

2012-03-01

In this paper, we present a novel method of visualizing flow in blood vessels. Our approach reads unstructured tetrahedral data, resamples it, and uses slice based 3D texture volume rendering. Due to the sparse structure of blood vessels, we utilize an octree to efficiently store the resampled data by discarding empty regions of the volume. We use animation to convey time series data, wireframe surface to give structure, and utilize the StarCAVE, a 3D virtual reality environment, to add a fully immersive element to the visualization. Our tool has great value in interdisciplinary work, helping scientists collaborate with clinicians, by improving the understanding of blood flow simulations. Full immersion in the flow field allows for a more intuitive understanding of the flow phenomena, and can be a great help to medical experts for treatment planning.

Hypercoagulability in response to elevated body temperature and central hypovolemia

DEFF Research Database (Denmark)

Meyer, Martin; Ostrowski, Sisse R; Overgaard, Flemming Anders

2013-01-01

Coagulation abnormalities contribute to poor outcomes in critically ill patients. In trauma patients exposed to a hot environment, a systemic inflammatory response syndrome, elevated body temperature, and reduced central blood volume occur in parallel with changes in hemostasis and endothelial...... damage. The objective of this study was to evaluate whether experimentally elevated body temperature and reduced central blood volume (CBV) per se affects hemostasis and endothelial activation....

Diagnostic Values of DCE-MRI and DSC-MRI for Differentiation Between High-grade and Low-grade Gliomas: A Comprehensive Meta-analysis.

Science.gov (United States)

Liang, Jianye; Liu, Dexiang; Gao, Peng; Zhang, Dong; Chen, Hanwei; Shi, Changzheng; Luo, Liangping

2018-03-01

This study aimed to collect the studies on the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and dynamic susceptibility contrast MRI (DSC-MRI) in differentiating the grades of gliomas, and evaluate the diagnostic performances of relevant quantitative parameters in glioma grading. We systematically searched studies on the diagnosis of gliomas with DCE-MRI or DSC-MRI in Medline, PubMed, China National Knowledge Infrastructure database, Cochrane Library, and Embase published between January 2005 and December 2016. Standardized mean differences and 95% confidence intervals were calculated for volume transfer coefficient (K trans ), volume fraction of extravascular extracellular space (V e ), rate constant of backflux (K ep ), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) using Review Manager 5.2 software. Sensitivity, specificity, area under the curve (AUC), and Begg test were calculated by Stata 12.0. Twenty-two studies with available outcome data were included in the analysis. The standardized mean difference of K trans values between high-grade glioma and low-grade glioma were 1.18 (0.91, 1.45); V e values were 1.43 (1.06, 1.80); K ep values were 0.65 (-0.05, 1.36); rCBV values were 1.44 (1.08, 1.81); and rCBF values were 1.17 (0.68, 1.67), respectively. The results were all significant statistically (P values (P = .07), and high-grade glioma had higher K trans , V e , rCBV, and rCBF values than low-grade glioma. AUC values of K trans , V e , rCBV, and rCBF were 0.90, 0.88, 0.93, and 0.73, respectively; rCBV had the largest AUC among the four parameters (P < .05). Both DCE-MRI and DSC-MRI are reliable techniques in differentiating the grades of gliomas, and rCBV was found to be the most sensitive one. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Longitudinal MRI evaluation of intracranial development and vascular characteristics of breast cancer brain metastases in a mouse model.

Directory of Open Access Journals (Sweden)

Heling Zhou

Full Text Available Longitudinal MRI was applied to monitor intracranial initiation and development of brain metastases and assess tumor vascular volume and permeability in a mouse model of breast cancer brain metastases. Using a 9.4T system, high resolution anatomic MRI and dynamic susceptibility contrast (DSC perfusion MRI were acquired at different time points after an intracardiac injection of brain-tropic breast cancer MDA-MB231BR-EGFP cells. Three weeks post injection, multifocal brain metastases were first observed with hyperintensity on T2-weighted images, but isointensity on T1-weighted post contrast images, indicating that blood-tumor-barrier (BTB at early stage of brain metastases was impermeable. Follow-up MRI revealed intracranial tumor growth and increased number of metastases that distributed throughout the whole brain. At the last scan on week 5, T1-weighted post contrast images detected BTB disruption in 160 (34% of a total of 464 brain metastases. Enhancement in some of the metastases was only seen in partial regions of the tumor, suggesting intratumoral heterogeneity of BTB disruption. DSC MRI measurements of relative cerebral blood volume (rCBV showed that rCBV of brain metastases was significantly lower (mean= 0.89±0.03 than that of contralateral normal brain (mean= 1.00±0.03; p<0.005. Intriguingly, longitudinal measurements revealed that rCBV of individual metastases at early stage was similar to, but became significantly lower than that of contralateral normal brain with tumor growth (p<0.05. The rCBV data were concordant with histological analysis of microvascular density (MVD. Moreover, comprehensive analysis suggested no significant correlation among tumor size, rCBV and BTB permeability. In conclusion, longitudinal MRI provides non-invasive in vivo assessments of spatial and temporal development of brain metastases and their vascular volume and permeability. The characteristic rCBV of brain metastases may have a diagnostic value.

Blood volume studies in chronic renal failure using radioactive 51Cr

International Nuclear Information System (INIS)

Chadda, V.S.; Mehta, S.R.; Mathur, D.

1975-01-01

Estimation of blood volume was carried out in 20 healthy subjects and in 25 patients suffering from chronic renal failure using radioactive 51 Cr. A detailed history, physical examination and investigations were also undertaken. On statistical evaluation, the red cell volume was diminished significantly in males and females but rise in blood volume was insignificant. Plasma volume was raised significantly in females but was insignificant in males. The reduction in red cell volume is due to reduced red cell mass because of chronic renal disease. Plasma volume may be elevated in order to compensate for decreased red cell volume. The variability in these two parameters results in variable blood volume. (author)

Image quality in CT perfusion imaging of the brain. The role of iodine concentration

Energy Technology Data Exchange (ETDEWEB)

Koenig, Matthias; Bueltmann, Eva; Bode-Schnurbus, Lucas; Koenen, Dirk; Mielke, Eckhart; Heuser, Lothar [Knappschaftskrankenhaus Langendreer, Department of Diagnostic and Interventional Radiology and Nuclear Medicine, Ruhr-University Bochum, Bochum (Germany)

2007-01-15

The purpose of this study was to evaluate the impact of various iodine contrast concentrations on image quality in computed tomography (CT) perfusion studies. Twenty-one patients with suspicion of cerebral ischemia underwent perfusion CT using two different iodine contrast concentrations: 11 patients received iomeprol 300 (iodine concentration: 300 mg/ml) while ten received the same volume of iomeprol 400 (iodine concentration: 400 mg/ml). Scan parameters were kept constant for both groups. Maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) were calculated from two adjacent slices. Quantitative comparisons were based on measurements of the maximum enhancement [Hounsfield units (HU)] and signal-to-noise index (SNI) on CBF, CBV, and TTP images. Determinations of grey-to-white-matter delineation for each iodine concentration were performed by two blinded readers. Only data from the non-ischemic hemispheres were considered. Both maximum enhancement and SNI values were higher after iomeprol 400, resulting in significantly better image quality in areas of low perfusion. No noteworthy differences were found for normal values of CBF, CBV, and TTP. Qualitative assessment of grey/white matter contrast on CBF and CBV maps revealed better performance for iomeprol 400. For brain perfusion studies, highly concentrated contrast media such as iomeprol 400 is superior to iomeprol 300. (orig.)

Pharmacological modulation of the BOLD response: a study of acetazolamide and glyceryl trinitrate in humans

DEFF Research Database (Denmark)

Asghar, Mohammed Sohail; Hansen, Adam E; Pedersen, Simon

2011-01-01

To examine the effect of acetazolamide, known to increase cerebral blood flow (CBF) and glyceryl trinitrate (GTN), known to increase cerebral blood volume (CBV) on the blood oxygenation level-dependent (BOLD) response in humans using 3 T magnetic resonance imaging (MRI), and to evaluate how...... pharmacological agents may modulate cerebral hemodynamic and thereby possibly the BOLD signal....

Regional MRI Perfusion Measures Predict Motor/Executive Function in Patients with Clinically Isolated Syndrome

Directory of Open Access Journals (Sweden)

Efrosini Z. Papadaki

2014-01-01

Full Text Available Background. Patients with clinically isolated syndrome (CIS demonstrate brain hemodynamic changes and also suffer from difficulties in processing speed, memory, and executive functions. Objective. To explore whether brain hemodynamic disturbances in CIS patients correlate with executive functions. Methods. Thirty CIS patients and forty-three healthy subjects, matched for age, gender, education level, and FSIQ, were administered tests of visuomotor learning and set shifting ability. Cerebral blood volume (CBV, cerebral blood flow (CBF, and mean transit time (MTT values were estimated in normal-appearing white matter (NAWM and normal-appearing deep gray Matter (NADGM structures, using a perfusion MRI technique. Results. CIS patients showed significantly elevated reaction time (RT on both tasks, while their CBV and MTT values were globally increased, probably due to inflammatory vasodilation. Significantly, positive correlation coefficients were found between error rates on the inhibition condition of the visuomotor learning task and CBV values in occipital, periventricular NAWM and both thalami. On the set shifting condition of the respective task significant, positive associations were found between error rates and CBV values in the semioval center and periventricular NAWM bilaterally. Conclusion. Impaired executive function in CIS patients correlated positively with elevated regional CBV values thought to reflect inflammatory processes.

Cerebral Hemodynamics in a Healthy Population Measured by Dynamic Susceptibility Contrast MR Imaging

International Nuclear Information System (INIS)

Helenius, J.; Soinne, L.; Tatlisumak, T.; Kaste, M.; Aronen, H.J.

2003-01-01

Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuro anatomic structures. Results: In gray matter, the following values were found (mean ± SD): CBV (4.6 ± 1.0 ml/100 g), CBF (94.2 ± 23.0 ml/100 g/min), and MTT (3.0 ± 0.6 s), and in white matter: CBV (1.3 ± 0.4 ml/100 g), CBF (19.6 ± 5.8 ml/100 g/min), and MTT (4.3 ± 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population

Cerebral Hemodynamics in a Healthy Population Measured by Dynamic Susceptibility Contrast MR Imaging

Energy Technology Data Exchange (ETDEWEB)

Helenius, J.; Soinne, L.; Tatlisumak, T.; Kaste, M. [Helsinki Univ. Central Hospital (Finland). Dept. of Neurology; Perkioe, J.; Salonen, O.; Savolainen, S. [Helsinki Univ. Central Hospital (Finland). Dept. of Radiology; Oestergaard, L. [Aarhus Univ. Hospital (Denmark). Dept. of Neuroradiology; Carano, R.A.D. [Synarc Inc., San Francisco, CA (United States); Aronen, H.J. [Helsinki Brain Research Center (Finland). Functional Brain Imaging Unit

2003-09-01

Purpose: To establish reference data and to study age-dependency for cerebral perfusion in various regions of the brain in a healthy population. Material and Methods: Eighty healthy subjects of both genders from 22 to 85 years of age were studied with spin echo echo-planar dynamic susceptibility contrast MR imaging (DSC MRI) at 1.5 T. Cerebral blood volume (CBV), cerebral blood flow (CBF), and contrast agent mean transit time (MTT) were calculated bilaterally for 20 distinct neuro anatomic structures. Results: In gray matter, the following values were found (mean {+-} SD): CBV (4.6 {+-} 1.0 ml/100 g), CBF (94.2 {+-} 23.0 ml/100 g/min), and MTT (3.0 {+-} 0.6 s), and in white matter: CBV (1.3 {+-} 0.4 ml/100 g), CBF (19.6 {+-} 5.8 ml/100 g/min), and MTT (4.3 {+-} 0.7 s). The perfusion parameters did not change with age, except for a tendency to an increase in gray matter MTT and CBV. Males exhibited higher MTT and CBV than females. No hemispheric difference was found in either gender. Conclusion: Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population.

The determination of blood volume in horses using stable isotope sup 50 Cr

Energy Technology Data Exchange (ETDEWEB)

Ito, Nobuhiko; Kunugiyama, Iwao; Tanaka, Masayoshi; Inoue, Megumi; Furukawa, Yoshinori (Kitasato Univ., Towada, Aomori (Japan). School of Veterinary Medicine and Animal Sciences); Hiraga, Atsushi; Yamanobe, Akira; Kubo, Katsuyoshi

1991-05-01

A method using stable isotope {sup 50}Cr was presented to determine equine blood volumes accurately in the field. The erythrocyte labelled with {sup 50}Cr was injected intravenously, then small amount of blood was collected at regular intervals, and the erythrocyte volume was measured from dilution rate of {sup 50}Cr. A blood volume was calculated from the erythrocyte volume and the packed cell volume (PCV). The present results suggested that the optimum time of collecting blood at rest was 2 h after injection of tagged blood. The red cell volumes and the total blood volumes of fifteen thoroughbred horses measured by the {sup 50}Cr method were 46.6+-9.9 and 133+-17 ml/kg body weight, respectively. The mean red cell volume of stallion was larger than mare (t-test, p<0.05), and three was no significant difference in the blood volume. (author).

Effect of pulmonary hyperinflation on central blood volume

DEFF Research Database (Denmark)

Mijacika, Tanja; Kyhl, Kasper; Frestad, Daria

2017-01-01

(11±7%) above the total lung capacity. All cardiac chambers decreased in volume and despite a heart rate increase of 24±29 bpm (39±50%), pulmonary blood flow decreased by 2783±1820mL (43±20%). The pulmonary transit time remained unchanged at 7.5±2.2s and pulmonary blood volume decreased by 354±176m...

Early activation of the coagulation system during lower body negative pressure

DEFF Research Database (Denmark)

Zaar, M; Johansson, P I; Nielsen, L B

2009-01-01

We considered that a moderate reduction of the central blood volume (CBV) may activate the coagulation system. Lower body negative pressure (LBNP) is a non-invasive means of reducing CBV and, thereby, simulates haemorrhage. We tested the hypothesis that coagulation markers would increase following...... moderate hypovolemia by exposing 10 healthy male volunteers to 10 min of 30 mmHg LBNP. Thoracic electrical impedance increased during LBNP (by 2.6 +/- 0.7 Omega, mean +/- SD; P pressure decreased (84 +/- 5 to 80...

Volumetric assessment of recurrent or progressive gliomas: comparison between F-DOPA PET and perfusion-weighted MRI

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Cicone, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Filss, Christian P.; Langen, Karl-Josef [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; RWTH Aachen Univ. Hospital (Germany). Dept. of Nuclear Medicine; Minniti, Giuseppe; Scaringi, Claudia [Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Rossi-Espagnet, Camilla; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Sapienza Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.); Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Galldiks, Norbert [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Cologne Univ. (Germany). Dept. of Neurology; Shah, N. Jon [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine

2015-05-01

To compare the diagnostic information obtained with 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET and relative cerebral blood volume (rCBV) maps in recurrent or progressive glioma. All patients with recurrent or progressive glioma referred for F-DOPA imaging at our institution between May 2010 and May 2014 were retrospectively included, provided that macroscopic disease was visible on conventional MRI images and that rCBV maps were available for comparison. The final analysis included 50 paired studies (44 patients). After image registration, automatic tumour segmentation of both sets of images was performed using the average signal in a large reference VOI including grey and white matter multiplied by 1.6. Tumour volumes identified by both modalities were compared and their spatial congruence calculated. The distances between F-DOPA uptake and rCBV hot spots, tumour-to-brain ratios (TBRs) and normalized histograms were also computed. On visual inspection, 49 of the 50 F-DOPA and 45 of the 50 rCBV studies were classified as positive. The tumour volume delineated using F-DOPA (F-DOPA{sub vol} {sub 1.6}) greatly exceeded that of rCBV maps (rCBV{sub vol} {sub 1.6}). The median F-DOPA{sub vol} {sub 1.6} and rCBV{sub vol} {sub 1.6} were 11.44 ml (range 0 - 220.95 ml) and 1.04 ml (range 0 - 26.30 ml), respectively (p < 0.00001). Overall, the median overlapping volume was 0.27 ml, resulting in a spatial congruence of 1.38 % (range 0 - 39.22 %). The mean hot spot distance was 27.17 mm (±16.92 mm). F-DOPA uptake TBR was significantly higher than rCBV TBR (1.76 ± 0.60 vs. 1.15 ± 0.52, respectively; p < 0.0001). The histogram analysis showed that F-DOPA provided better separation of tumour from background. In 6 of the 50 studies (12 %), however, physiological uptake in the striatum interfered with tumour delineation. The information provided by F-DOPA PET and rCBV maps are substantially different. Image interpretation is easier and a larger tumour extent

Short and long-term effects of irbesartan on intradialytic central haemodynamics: A randomised double-blind placebo-controlled one-year intervention trial (the SAFIR study)

DEFF Research Database (Denmark)

Peters, Christian Daugaard; Kjærgaard, Krista Dybtved; Jensen, Jens Dam

2014-01-01

), stroke volume (SV), central blood volume (CBV), total peripheral resistance (TPR), mean arterial BP (MAP), and heart rate (HR) were measured within the first (HDSTART) and last (HDEND) 30 minutes during HD using the Transonic saline dilution technique. Results Eighty-two patients were randomised (placebo....../ARB: 41/41). Predialytic systolic BP decreased significantly, but similarly in both groups during the study period. The total number of IDH episodes was (placebo/ARB) 22/25 (P=0.7). Mean HDSTART and mean HDEND CO, SV, TPR, HR, and MAP were stable and similar in the two groups, whereas CBV increased...... equally and significantly over time. The mean intradialytic haemodynamic response showed decreased CO, SV, MAP, and CBV, whereas HR increased from HDSTART to HDEND. TPR did not change significantly. Overall, this pattern remained stable over time in both groups and there was no significant impact of ARB...

Parametric Response Maps of Perfusion MRI May Identify Recurrent Glioblastomas Responsive to Bevacizumab and Irinotecan

Science.gov (United States)

Aquino, Domenico; Cuppini, Lucia; Anghileri, Elena; Finocchiaro, Gaetano; Bruzzone, Maria Grazia; Eoli, Marica

2014-01-01

Background Perfusion weighted imaging (PWI) can be used to measure key aspects of tumor vascularity in vivo and recent studies suggest that perfusion imaging may be useful in the early assessment of response to angiogenesis inhibitors. Aim of this work is to compare Parametric Response Maps (PRMs) with the Region Of Interest (ROI) approach in the analysis of tumor changes induced by bevacizumab and irinotecan in recurrent glioblastomas (rGBM), and to evaluate if changes in tumor blood volume measured by perfusion MRI may predict clinical outcome. Methods 42 rGBM patients with KPS ≥50 were treated until progression, as defined by MRI with RANO criteria. Relative cerebral blood volume (rCBV) variation after 8 weeks of treatment was calculated through semi-automatic ROI placement in the same anatomic region as in baseline. Alternatively, rCBV variations with respect to baseline were calculated into the evolving tumor region using a voxel-by-voxel difference. PRMs were created showing where rCBV significantly increased, decreased or remained unchanged. Results An increased blood volume in PRM (PRMCBV+) higher than 18% (first quartile) after 8 weeks of treatment was associated with increased progression free survival (PFS; 24 versus 13 weeks, p = 0.045) and overall survival (OS; 38 versus 25 weeks, p = 0.016). After 8 weeks of treatment ROI analysis showed that mean rCBV remained elevated in non responsive patients (4.8±0.9 versus 5.1±1.2, p = 0.38), whereas decreased in responsive patients (4.2±1.3 versus 3.8±1.6 p = 0.04), and re-increased progressively when patients approached tumor progression. Conclusions Our data suggest that PRMs can provide an early marker of response to antiangiogenic treatment and warrant further confirmation in a larger cohort of GBM patients. PMID:24675671

Radionuclide method for blood volume determination in kidneys

International Nuclear Information System (INIS)

Trindev, P.; Nikolov, D.; Shejretova, E.; Garcheva-Tsacheva, M.

1989-01-01

The method is applied in nephrology for diagnosing changes in blood circulation of the kidneys. The blood volume of each kidney is determined separately by perfusion angioscintigraphy (PAS) with improved accuracy. The method consists in intravenous injection of 300-450 MBq 99m Tc for in-vivo labelling of the erythrocytes. About 30 images are registered every 2 sec, and through zones of interest perfusion histograms of kidneys are derived. Ten minutes later kidneys images (one full-face and two profiles) are registered. Correction coefficients for kidneys depth are derived and the activities registered according to full-face images and amplitudes of perfusion histograms are corrected. The activity of 1 ml blood is determined from blood sample of the patient. The blood volume of each kidney is expressed as a ratio of the activity corrected for background and depth and the activity of 1 ml blood of the sample. 1 claim

Application of histogram analysis for the evaluation of vascular permeability in glioma by the K2 parameter obtained with the dynamic susceptibility contrast method: Comparisons with Ktrans obtained with the dynamic contrast enhance method and cerebral blood volume.

Science.gov (United States)

Taoka, Toshiaki; Kawai, Hisashi; Nakane, Toshiki; Hori, Saeka; Ochi, Tomoko; Miyasaka, Toshiteru; Sakamoto, Masahiko; Kichikawa, Kimihiko; Naganawa, Shinji

2016-09-01

The "K2" value is a factor that represents the vascular permeability of tumors and can be calculated from datasets obtained with the dynamic susceptibility contrast (DSC) method. The purpose of the current study was to correlate K2 with Ktrans, which is a well-established permeability parameter obtained with the dynamic contrast enhance (DCE) method, and determine the usefulness of K2 for glioma grading with histogram analysis. The subjects were 22 glioma patients (Grade II: 5, III: 6, IV: 11) who underwent DSC studies, including eight patients in which both DSC and DCE studies were performed on separate days within 10days. We performed histogram analysis of regions of interest of the tumors and acquired 20th percentile values for leakage-corrected cerebral blood volume (rCBV20%ile), K2 (K220%ile), and for patients who underwent a DCE study, Ktrans (Ktrans20%ile). We evaluated the correlation between K220%ile and Ktrans20%ile and the statistical difference between rCBV20%ile and K220%ile. We found a statistically significant correlation between K220%ile and Ktrans20%ile (r=0.717, pK220%ile showed a statistically significant (pK2 value calculated from the DSC dataset, which can be obtained with a short acquisition time, showed a correlation with Ktrans obtained with the DCE method and may be useful for glioma grading when analyzed with histogram analysis. Copyright © 2016 Elsevier Inc. All rights reserved.

Epitopes recognized by CBV4 responding T cells: effect of type 1 diabetes and associated HLA-DR-DQ haplotypes

International Nuclear Information System (INIS)

Marttila, Jane; Hyoety, Heikki; Naentoe-Salonen, Kirsti; Simell, Olli; Ilonen, Jorma

2004-01-01

The present study aimed at characterizing the epitopes recognized by coxsackievirus B4 (CBV4)-specific T-cell lines established from 23 children with type 1 diabetes (T1D) and 29 healthy children with T1D risk-associated HLA genotypes. Responsiveness to VP1 region was dependent on the specific infection history as 55% of the T-cell lines from donors with neutralizing antibodies to CBV serotypes responded to VP1 peptides compared to none of the T-cell lines from other donors (P = 0.01). The pattern of recognized peptides was dependent of the HLA genotype. Forty-two percent of the T-cell lines from donors carrying the HLA-(DR4)-DQB1*0302 haplotype responded to VP1 peptides 71-80 compared to none of the T-cell lines from donors without this haplotype (P = 0.02). No evidence for the existence of diabetes-specific epitopes was found. Only few epitopes were exclusive recognized by T cells from diabetic children, and in each case only one or two T-cell lines were responding

Different injection techniques in the assessment of central haemodynamics in patients with cirrhosis

DEFF Research Database (Denmark)

Christensen, Tine N; Mortensen, Christian; Henriksen, Jens H

2013-01-01

Objective. Patients with cirrhosis often present with an abnormal distribution of blood volume with a reduced central blood volume (CBV) and central circulation time (CCT). In this group of patients it is important to determine the central haemodynamics as accurately as possible. The purpose...... of the present study was to compare an alternative injection technique by injecting technetium-labelled human serum albumin ((99m)Tc-HSA) from a deposit within the catheter lumen with the conventional injection technique by injecting iodine-labelled human serum albumin ((125)I-HSA) directly from a syringe...... was significantly shorter, and CO and CBV were significantly lower when determined by the alternative catheter deposit injection technique compared to determination by the traditional syringe deposit injection technique. The mean difference (bias) between CCT measured with the two methods was 0.38 s with limits...

Peritumoral brain edema in intracranial tumor evaluated by CT perfusion imaging

International Nuclear Information System (INIS)

Shi Yuxin; Xu Jianfeng

2005-01-01

Objective: To semi-quantitatively evaluate the cerebral perfusion in the peritumoral brain edema of cerebral tumors using CT perfusion imaging. Methods: Twenty-one patients with peritumoral brain edema (including pathologically confirmed meningiomas n=4, metastasis n=10, gliomas n=7) were examined by CT perfusion imaging. The regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), and mean transit time (MTT) were calculated for peritumoral brain edema and the contralateralwhite matter. The rCBF and rCBV were compared between peritumoral brain edema and the contralateral white matter. The mean ratios (edema/contralateral white matter) of rCBF and rCBV were compared among the three tumors. Results: The rCBF and rCBV of peritumoral brain edema were significantly lower than those of contralateral white matter in patients with meningiomas and metastasis (rCBF: t=2.92 and 3.82, P 0.05). The mean ratios (edema/contralateralwhite matter) of rCBF and rCBV were not significantly different between meningiomas and metastasis (t=0.23 and 0.73, P>0.05), but both of them were significantly lower than those of gliomas (t=3.05 and 3.37, P<0.01, 0.005). Conclusion: The rCBF and rCBV in peritumoral brain edema were significantly lower than those of contralateral white matter in patients with meningiomas and metastasis, while almost the same with or higher than those of contralateral white matter in patients with gliomas. CT perfusion can provide quantitative information of blood flow in peritumoral brain edema, and is useful in the diagnosis and follow-up of cerebral tumors. (authors)

Diagnostic and Prognostic Impact of pc-ASPECTS Applied to Perfusion CT in the Basilar Artery International Cooperation Study.

Science.gov (United States)

Pallesen, Lars-Peder; Gerber, Johannes; Dzialowski, Imanuel; van der Hoeven, Erik J R J; Michel, Patrik; Pfefferkorn, Thomas; Ozdoba, Christoph; Kappelle, L Jaap; Wiedemann, Baerbel; Khomenko, Andrei; Algra, Ale; Hill, Michael D; von Kummer, Ruediger; Demchuk, Andrew M; Schonewille, Wouter J; Puetz, Volker

2015-01-01

The posterior circulation Acute Stroke Prognosis Early CT Score (pc-APECTS) applied to CT angiography source images (CTA-SI) predicts the functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS). We assessed the diagnostic and prognostic impact of pc-ASPECTS applied to perfusion CT (CTP) in the BASICS registry population. We applied pc-ASPECTS to CTA-SI and cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) parameter maps of BASICS patients with CTA and CTP studies performed. Hypoattenuation on CTA-SI, relative reduction in CBV or CBF, or relative increase in MTT were rated as abnormal. CTA and CTP were available in 27/592 BASICS patients (4.6%). The proportion of patients with any perfusion abnormality was highest for MTT (93%; 95% confidence interval [CI], 76%-99%), compared with 78% (58%-91%) for CTA-SI and CBF, and 46% (27%-67%) for CBV (P < .001). All 3 patients with a CBV pc-ASPECTS < 8 compared to 6/23 patients with a CBV pc-ASPECTS ≥ 8 had died at 1 month (RR 3.8; 95% CI, 1.9-7.6). CTP was performed in a minority of the BASICS registry population. Perfusion disturbances in the posterior circulation were most pronounced on MTT parameter maps. CBV pc-ASPECTS < 8 may indicate patients with high case fatality. Copyright © 2014 by the American Society of Neuroimaging.

Plasma volume changes during hypoglycaemia: the effect of arterial blood sampling

DEFF Research Database (Denmark)

Hilsted, J; Bendtsen, Flemming; Christensen, N J

1990-01-01

To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... hypoglycaemia. The magnitude of the changes in arterial and venous blood were not significantly different. These results indicate that the above changes in blood volume and composition are whole-body phenomena: furthermore, the major part of the changes are likely to occur in tissues other than upper extremity...... of albumin in arterial and venous blood in seven healthy subjects before and during insulin-induced hypoglycaemia. In both vascular sites blood 51Cr content and the haematocrit increased, plasma volume and intravascular albumin content decreased and the transcapillary escape rate of albumin increased during...

Predictive value of PWI for blood supply and T1-spin echo MRI for consistency of pituitary adenoma

Energy Technology Data Exchange (ETDEWEB)

Ma, Zengyi; He, Wenqiang; Zhao, Yao; Zhang, Qilin; Li, Shiqi; Wang, Yongfei [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Yuan, Jie; Wu, Yue; Yao, Zhenwei [Fudan University, Department of Radiology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Chen, Hong [Fudan University, Department of Neuropathology, Huashan Hospital, Shanghai Medical College, Shanghai (China)

2016-01-15

It is a common view that consistency and blood supply of pituitary adenoma (PA) can influence the surgical effect. The aim of this study was to determine whether MRI signal intensity (SI) was correlated to the consistency or blood supply of pituitary macroadenoma. Forty eight pituitary macroadenoma patients were underwent preoperative MRI, including precontrast and contrast-enhanced (CE) T1-spin echo (T1-SE) imaging, CE-sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE) imaging, and perfusion-weighted imaging (PWI). The tumor consistency and blood supply were determined by neurosurgeons. The expression of collagen IV and MIB-1 was detected with immunohistology. The correlation of the relative SI (rSI) values (tumor to normal frontal white matter SI) and PWI data to the tumor consistency, blood supply, and the expression level of collagen IV and MIB-1 was statistically studied by Kruskal-Wallis rank test (K-W test). A significant correlation was observed between the tumor consistency and the rSI on precontrast T1-SE imaging (P = 0.004) but not on CE T1-SE and CE SPACE imaging. The expression of collagen IV was also significantly associated with rSI on T1-SE imaging (P = 0.010). The blood supply was correlated with the relative CBV (rCBV) (P = 0.030). In addition, the expression of MIB-1 was correlated with rSI of CE T1-SE imaging (P = 0.007). Our results suggest that T1-SE imaging may be a simple and useful method for predicting consistency of PA. CBV value can provide helpful information for assessing the blood supply of pituitary macroadenoma. (orig.)

The determination of chromium-50 in human blood and its utilization for blood volume measurements

International Nuclear Information System (INIS)

Zeisler, R.; Young, I.

1986-01-01

Possible relationships between insufficient blood volume increases during pregnancy and infant mortality could be established with an adequate measurement procedure. An accurate and precise technique for blood volume measurements has been found in the isotope dilution technique using chromium-51 as a label for red blood cells. However, in a study involving pregnant women, only stable isotopes can be used for labeling. Stable chromium-50 can be determined in total blood samples before and after dilution experiments by neutron activation analysis (NAA) or mass spectrometry. However, both techniques may be affected by insufficient sensitivity and contamination problems at the inherently low natural chromium concentrations to be measured in the blood. NAA procedures involving irradiations with highly thermalized neutrons at a fluence rate of 2x10 13 n/cm 2 xs and low background gamma spectrometry are applied to the analysis of total blood. Natural levels of chromium-50 in human and animal blood have been found to be <0.1 ng/mL; i.e., total chromium levels of <3 ng/mL. Based on the NAA procedure, a new approach to the blood volume measurement via chromium-50 isotope dilution has been developed which utilizes the ratio of the induced activities of chromium-51 to the iron-59 in three blood samples taken from each individual, namely blank, labeled and diluted labeled blood. (author)

Capillary dysfunction is associated with symptom severity and neurodegeneration in Alzheimer's disease

DEFF Research Database (Denmark)

Nielsen, Rune B; Egefjord, Lærke; Angleys, Hugo

2017-01-01

testing, structural magnetic resonance imaging (MRI), and perfusion MRI at baseline and after 6 months. We measured cortical thickness, microvascular cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and capillary transit time heterogeneity (CTH) and estimated tissue oxygen......INTRODUCTION: We examined whether cortical microvascular blood volume and hemodynamics in Alzheimer's disease (AD) are consistent with tissue hypoxia and whether they correlate with cognitive performance and the degree of cortical thinning. METHODS: Thirty-two AD patients underwent cognitive...

Contribution of dynamic contrast MR imaging to the differentiation between dural metastasis and meningioma

International Nuclear Information System (INIS)

Kremer, S.; Grand, S.; Le Bas, J.F.; Remy, C.; Pasquier, B.; Benabid, A.L.; Bracard, S.

2004-01-01

To determine the perfusion-sensitive characteristics of cerebral dural metastases and compare them with the data on meningiomas. Twenty-two patients presenting with dural tumor underwent conventional and dynamic susceptibility-contrast MR imaging: breast carcinoma metastases, two patients; colorectal carcinoma metastasis, one patient; lung carcinoma metastasis, one patient; Merkel carcinoma metastasis, one patient; lymphoma, one patient; meningiomas, 16 patients. The imaging characteristics were analyzed using conventional MR imaging. The cerebral blood volume (CBV) maps were obtained for each patient and the relative CBV (rCBV) in different areas was calculated using the ratio between the CBV in the pathological area (CBVp) and in the contralateral white matter (CBVn). The differentiation between a meningioma and a dural metastasis can be difficult using conventional MR imaging. The rCBVs of lung carcinoma metastasis (1 case: 1.26), lymphoma (1 case: 1.29), breast carcinoma metastasis (2 cases: 1.50,1.56) and rectal carcinoma metastasis (1 case: 3.34) were significantly lower than that of meningiomas (16 cases: mean rCBV = 8.97±4.34, range 4-18). Merkel carcinoma metastasis (1 case: 7.56) showed an elevated rCBV, not different from that of meningiomas. Dural metastases are sometimes indistinguishable from meningiomas using conventional MR imaging. rCBV mapping can provide additional information by demonstrating a low rCBV which may suggest the diagnosis of metastasis. (orig.)

Weak correlations between hemodynamic signals and ongoing neural activity during the resting state

Science.gov (United States)

Winder, Aaron T.; Echagarruga, Christina; Zhang, Qingguang; Drew, Patrick J.

2017-01-01

Spontaneous fluctuations in hemodynamic signals in the absence of a task or overt stimulation are used to infer neural activity. We tested this coupling by simultaneously measuring neural activity and changes in cerebral blood volume (CBV) in the somatosensory cortex of awake, head-fixed mice during periods of true rest, and during whisker stimulation and volitional whisking. Here we show that neurovascular coupling was similar across states, and large spontaneous CBV changes in the absence of sensory input were driven by volitional whisker and body movements. Hemodynamic signals during periods of rest were weakly correlated with neural activity. Spontaneous fluctuations in CBV and vessel diameter persisted when local neural spiking and glutamatergic input was blocked, and during blockade of noradrenergic receptors, suggesting a non-neuronal origin for spontaneous CBV fluctuations. Spontaneous hemodynamic signals reflect a combination of behavior, local neural activity, and putatively non-neural processes. PMID:29184204

CT and MR perfusion can discriminate severe cerebral hypoperfusion from perfusion absence: evaluation of different commercial software packages by using digital phantoms

Energy Technology Data Exchange (ETDEWEB)

Uwano, Ikuko; Kudo, Kohsuke; Sasaki, Makoto [Iwate Medical University, Advanced Medical Research Center, Morioka (Japan); Christensen, Soren [University of Melbourne, Royal Melbourne Hospital, Departments of Neurology and Radiology, Victoria (Australia); Oestergaard, Leif [Aarhus University Hospital, Department of Neuroradiology, Center for Functionally Integrative Neuroscience, DK, Aarhus C (Denmark); Ogasawara, Kuniaki; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan)

2012-05-15

Computed tomography perfusion (CTP) and magnetic resonance perfusion (MRP) are expected to be usable for ancillary tests of brain death by detection of complete absence of cerebral perfusion; however, the detection limit of hypoperfusion has not been determined. Hence, we examined whether commercial software can visualize very low cerebral blood flow (CBF) and cerebral blood volume (CBV) by creating and using digital phantoms. Digital phantoms simulating 0-4% of normal CBF (60 mL/100 g/min) and CBV (4 mL/100 g/min) were analyzed by ten software packages of CT and MRI manufacturers. Region-of-interest measurements were performed to determine whether there was a significant difference between areas of 0% and areas of 1-4% of normal flow. The CTP software detected hypoperfusion down to 2-3% in CBF and 2% in CBV, while the MRP software detected that of 1-3% in CBF and 1-4% in CBV, although the lower limits varied among software packages. CTP and MRP can detect the difference between profound hypoperfusion of <5% from that of 0% in digital phantoms, suggesting their potential efficacy for assessing brain death. (orig.)

A study of cerebral circulation in patients on moderate hypothermia therapy

International Nuclear Information System (INIS)

Honda, Mitsuru; Kushida, Tsuyoshi; Nagao, Takeki; Seiki, Yoshikatsu; Shibata, Iekado

2003-01-01

Recently, moderate hypothermia with cooling of the brain to 32-33 deg C has been widely applied to patients with severe brain damage. We evaluated the cerebral circulation of patients treated with moderate hypothermia therapy. In 16 patients with severe brain damage, both Xe-CT and Perfusion CT were performed during moderate hypothermia. The study included 5 head injury patients, 6 anoxic brain patients, 2 subarachnoid hemorrhage patients, 2 cerebral embolization patients and 1 cerebral hemorrhage patient. We measured cerebral blood flow (CBF) values using Xe-CT and mean transit time (MTT) by Perfusion CT and calculated cerebral blood volume (CBV) using an AZ-7000W98 computer system. In 16 patients, moderate hypothermia decreased both CBF (21.4±14.0 ml/100 g/min) and CBV (3.4±2.9 ml/100 g) and increased MTT (9.6±l.9 sec) compared to normal volunteers. However, patients who became brain death during moderate hypothermia maintained high levels of CBF and CBV. Based on the present results, we propose that reduction of CBV and CBF by moderate hypothermia can play important role in protecting brain from damage. (author)

Dynamic CT perfusion imaging of intra-axial brain tumours: differentiation of high-grade gliomas from primary CNS lymphomas

International Nuclear Information System (INIS)

Schramm, Peter; Xyda, Argyro; Knauth, Michael; Klotz, Ernst; Tronnier, Volker; Hartmann, Marius

2010-01-01

Perfusion computed tomography (PCT) allows to quantitatively assess haemodynamic characteristics of brain tissue. We investigated if different brain tumor types can be distinguished from each other using Patlak analysis of PCT data. PCT data from 43 patients with brain tumours were analysed with a commercial implementation of the Patlak method. Four patients had low-grade glioma (WHO II), 31 patients had glioblastoma (WHO IV) and eight patients had intracerebral lymphoma. Tumour regions of interest (ROIs) were drawn in a morphological image and automatically transferred to maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and permeability (K Trans ). Mean values were calculated, group differences were tested using Wilcoxon and Mann Whitney U-tests. In comparison with normal parenchyma, low-grade gliomas showed no significant difference of perfusion parameters (p > 0.05), whereas high-grade gliomas demonstrated significantly higher values (p Trans , p Trans values compared with unaffected cerebral parenchyma (p = 0.0078) but no elevation of CBV. High-grade gliomas show significant higher CBV values than lymphomas (p = 0.0078). PCT allows to reliably classify gliomas and lymphomas based on quantitative measurements of CBV and K Trans . (orig.)

Diagnostic performance of PWI/DWI MRI parameters in discriminating hyperacute versus acute ischaemic stroke: Finding the best thresholds

International Nuclear Information System (INIS)

Roldan-Valadez, E.; Gonzalez-Gutierrez, O.; Martinez-Lopez, M.

2012-01-01

Aim: To determine the accuracy of the perfusion/diffusion-weighted imaging (PWI/DWI) parameters [time to peak (TTP), mean time to peak (MTT), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) maps]; in the evaluation of acute versus hyperacute ischaemic stroke. Materials and methods: Fifty-five patients with symptomatic hyperacute (first 6 h) or acute (7–24 h) ischaemic stroke underwent diffusion and perfusion evaluation. Statistical analysis included Student’s t-test, receiver operating characteristics (ROC) analysis of apparent diffusion coefficient (ADC), TTP, MTT, CBV, and CBF; correlation, linear, and logistic regression analysis. Results: Area under receiver operating characteristics (AUROC) analysis identified the ADC cut-off value 385 × 10 −6 mm 2 /s, MTT at 109.5%, TTP at 3.05 s, CBV at 129%, and CBF at 98.5% (the record of the time of onset was considered the reference standard). The best performance corresponded to TTP, which showed a sensitivity of 0.94 and specificity of 0.88 (p 3 s with no visible changes in diffusion. ADC, rCBF, and rCBV are not useful for discriminating between acute and hyperacute ischaemic stroke.

Cerebral hemodynamic changes measured by gradient-echo or spin-echo bolus tracking and its correlation to changes in ICA blood flow measured by phase-mapping MRI

DEFF Research Database (Denmark)

Marstrand, J.R.; Rostrup, Egill; Garde, Ellen

2001-01-01

Changes in cerebral blood flow (CBF) induced by Acetazolamide (ACZ) were measured using dynamic susceptibility contrast MRI (DSC-MRI) with both spin echo (SE) EPI and gradient echo (GE) EPI, and related to changes in internal carotid artery (ICA) flow measured by phase-mapping. Also examined...... increase in CBF and CBV in response to ACZ, while SE-EPI measured a significant increase in CBV and MTT. CBV and MTT change measured by SE-EPI was sensitive to previous bolus injections. There was a significant linear relation between change in CBF measured by GE-EPI and change in ICA flow. In conclusion......, GE-EPI under the present condition was superior to SE-EPI in monitoring cerebral vascular changes...

Role of CT perfusion imaging in evaluating the effects of multiple burr hole surgery on adult ischemic Moyamoya disease

Energy Technology Data Exchange (ETDEWEB)

Dai, Dong Wei; Zhao, Wen Yuan; Yang, Zhi Gang; Li, Qiang; Liu, Jian Min [Second Military Medical University, Department of Neurosurgery, Changhai Hospital, Shanghai (China); Zhang, Yong Wei [Second Military Medical University, Department of Neurology, Changhai Hospital, Shanghai (China); Xu, Bing; Ma, Xiao Long; Tian, Bing [Second Military Medical University, Department of Radiology, Changhai Hospital, Shanghai (China)

2013-12-15

To evaluate the effects of the multiple burr hole (MBH) revascularization on ischemic type adult Moyamoya disease (MMD) by computed tomography perfusion (CTP). Eighty-six ischemic MMD patients received CTP 1 week before and 3 weeks after MBH operation. Fifty-seven patients received it again at 6 month and underwent digital subtraction angiography (DSA) and mRS follow-up. Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and relative values of ischemic symptomatic hemispheres were measured. Differences in pre- and post-surgery perfusion CT values were assessed. There were significant differences of CBF, TTP, and relative time to peak (rTTP) in ischemic hemisphere between 1 week before and 3 weeks after surgery, and no significant difference in relative cerebral blood flow (rCBF), CBV, relative cerebral blood volume (rCBV), MTT, relative mean transit time (rMTT). According to whether there was symptom improvement or not on 3 weeks after MBH, the rTTP value was not statistically significant in the patients whose symptoms were not improved at all on 3 weeks after operation. Six-month follow-up showed that CBF, rCBF, and rCBV values were significantly higher than those before operation. Postoperative MTT, TTP, rMTT, and rTTP values were significantly lower than those before operation. CTP is a sensitive method to obtain functional imaging of cerebral microcirculation, which can be a noninvasive assessment of the abnormalities of intracranial arteries and cerebral perfusion changes in MMD before and after surgery. CBF and TTP map, especially the relative values of TTP, seems to have the capability of being quite sensitive to the presence of altered brain perfusion at early time after indirect revascularization. (orig.)

Facing Contrast-Enhancing Gliomas: Perfusion MRI in Grade III and Grade IV Gliomas according to Tumor Area

Directory of Open Access Journals (Sweden)

Anna Luisa Di Stefano

2014-01-01

Full Text Available Tumoral neoangiogenesis characterizes high grade gliomas. Relative Cerebral Blood Volume (rCBV, calculated with Dynamic Susceptibility Contrast (DSC Perfusion-Weighted Imaging (PWI, allows for the estimation of vascular density over the tumor bed. The aim of the study was to characterize putative tumoral neoangiogenesis via the study of maximal rCBV with a Region of Interest (ROI approach in three tumor areas—the contrast-enhancing area, the nonenhancing tumor, and the high perfusion area on CBV map—in patients affected by contrast-enhancing glioma (grades III and IV. Twenty-one patients were included: 15 were affected by grade IV and 6 by grade III glioma. Maximal rCBV values for each patient were averaged according to glioma grade. Although rCBV from contrast-enhancement and from nonenhancing tumor areas was higher in grade IV glioma than in grade III (5.58 and 2.68; 3.01 and 2.2, resp., the differences were not significant. Instead, rCBV recorded in the high perfusion area on CBV map, independently of tumor compartment, was significantly higher in grade IV glioma than in grade III (7.51 versus 3.78, P=0.036. In conclusion, neoangiogenesis encompasses different tumor compartments and CBV maps appear capable of best characterizing the degree of neovascularization. Facing contrast-enhancing brain tumors, areas of high perfusion on CBV maps should be considered as the reference areas to be targeted for glioma grading.

Acute cerebral stroke imaging and brain perfusion with the use of high-concentration contrast media

Energy Technology Data Exchange (ETDEWEB)

Miles, K.A. [Wesley Research Inst., The Wesley Hospital, Brisbane (Australia); Brighton and Sussex Medical School, Univ. of Sussex, Falmer, Brighton (United Kingdom)

2003-12-01

Acute cerebral stroke remains a major cause of death among adults and the emergence of new therapies has created a need for early and rapid imaging at a time when conventional CT is either normal or demonstrates subtle abnormalities that are easy to misinterpret. Perfusion CT uses the temporal changes in cerebral and blood attenuation during a rapid series of images acquired without table movement following an intravenous bolus of contrast medium to generate images of mean transit time (MTT) cerebral blood volume (CBV) and perfusion. Reduced perfusion with preserved CBV is indicative of reversible ischaemia, whereas a matched reduction in perfusion and CBV implies infarction. The CT perfusion imaging can positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, provide an indication as to prognosis and potentially select those patients for whom thrombolysis is appropriate. Perfusion CT offers a powerful adjunct to MDCT based imaging of cerebrovascular disease, but further clinical validation is required. (orig.)

Blood cell labeling with technetium-99m. II. Measurement of circulating blood volume by sup(99m)Tc-labeled red blood cells

Energy Technology Data Exchange (ETDEWEB)

Uchida, T; Yoshida, H; Matsuda, S; Kimura, H; Miura, N [Fukushima Medical Coll. (Japan)

1978-02-01

Using a labeling method with sup(99m)Tc-pertechnetate to red blood cells (RBC), circulating blood volume was measured in comparison with that from /sup 51/Cr-labeled RBC method. The technique is easier than already published methods, because CIS kit for sup(99m)Tc-RBC labeling (TCK-11) became to be available recently. Two mls of ACD-anticoagulated blood were withdrawn and 0.5 ml of reducing reagent prepared just before use was added to blood, waiting 5 minutes and discarding the serum after centrifugation, then adding 100 ..mu..Ci of sup(99m)Tc. After washing the labeled cells by isotonic saline, cells were re-suspended in 10 ml of saline and injected to the subject. Blood specimen was obtained 10, 30, 60 and 120 minutes after infusion and blood volume was calculated by the usual way. Circulating blood volume by sup(99m)Tc was well correlated with that by /sup 51/Cr (=0.98, p 0.01), however, the value calculated from sup(99m)Tc were 4.8 percent higher than those by /sup 51/Cr, which suggested the elution of sup(99m)Tc from labeled RBC. sup(99m)Tc method has the advantages that higher radioactivity can be obtained in small amount of blood, which is useful in the determination of blood volume in children or in small animals in the laboratory. The measurement of blood volume of the mouse was done by using sup(99m)Tc method. The results were 1.70 +- 0.06 ml (6.35 +- 0.18%/gm), which coincided with the values reported previously. Because of it's short half life and low radiation dosage to the patients, sup(99m)Tc method will be recommended in the field of pediatrics or in patients with polycythemia or congestive heart failure, who are requested the repeated measurement of blood volume.

Influence of Gravity on Blood Volume and Flow Distribution

Science.gov (United States)

Pendergast, D.; Olszowka, A.; Bednarczyk, E.; Shykoff, B.; Farhi, L.

1999-01-01

In our previous experiments during NASA Shuttle flights SLS 1 and 2 (9-15 days) and EUROMIR flights (30-90 days) we observed that pulmonary blood flow (cardiac output) was elevated initially, and surprisingly remained elevated for the duration of the flights. Stroke volume increased initially and then decreased, but was still above 1 Gz values. As venous return was constant, the changes in SV were secondary to modulation of heart rate. Mean blood pressure was at or slightly below 1 Gz levels in space, indicating a decrease in total peripheral resistance. It has been suggested that plasma volume is reduced in space, however cardiac output/venous return do not return to 1 Gz levels over the duration of flight. In spite of the increased cardiac output, central venous pressure was not elevated in space. These data suggest that there is a change in the basic relationship between cardiac output and central venous pressure, a persistent "hyperperfusion" and a re-distribution of blood flow and volume during space flight. Increased pulmonary blood flow has been reported to increase diffusing capacity in space, presumably due to the improved homogeneity of ventilation and perfusion. Other studies have suggested that ventilation may be independent of gravity, and perfusion may not be gravity- dependent. No data for the distribution of pulmonary blood volume were available for flight or simulated microgravity. Recent studies have suggested that the pulmonary vascular tree is influenced by sympathetic tone in a manner similar to that of the systemic system. This implies that the pulmonary circulation is dilated during microgravity and that the distribution of blood flow and volume may be influenced more by vascular control than by gravity. The cerebral circulation is influenced by sympathetic tone similarly to that of the systemic and pulmonary circulations; however its effects are modulated by cerebral autoregulation. Thus it is difficult to predict if cerebral perfusion is

Volume-dependent hemodynamic effects of blood collection in canine donors - evaluation of 13% and 15% of total blood volume depletion

Directory of Open Access Journals (Sweden)

RUI R.F. FERREIRA

2015-03-01

Full Text Available Background: There is no consensus regarding the blood volume that could be safely donated by dogs, ranging from 11 to 25% of its total blood volume (TBV. No previous studies evaluated sedated donors.Aim: To evaluate the hemodynamic effects of blood collection from sedated and non-sedated dogs and to understand if such effects were volume-dependent.Materials and Methods: Fifty three donations of 13% of TBV and 20 donations of 15% TBV were performed in dogs sedated with diazepam and ketamine. Additionally, a total of 30 collections of 13% TBV and 20 collections of 15% TBV were performed in non-sedated dogs. Non-invasive arterial blood pressures and pulse rates were registered before and 15 min after donation. Results: Post-donation pulse rates increased significantly in both sedated groups, with higher differences in the 15% TBV collections. Systolic arterial pressures decreased significantly in these groups, while diastolic pressures increased significantly in 13% TBV donations. Non-sedated groups revealed a slight, but significant, SBP decrease. No clinical signs related to donations were registered.Conclusion: These results suggest that the collection of 15% TBV in sedated donors induces hemodynamic variations that may compromise the harmlessness of the procedure, while it seems to be a safe procedure in non-sedated dogs.

Perfusion MRI derived indices of microvascular shunting and flow control correlate with tumor grade and outcome in patients with cerebral glioma

DEFF Research Database (Denmark)

Tietze, Anna; Mouridsen, Kim; Lassen-Ramshad, Yasmin

2015-01-01

Objectives: Deficient microvascular blood flow control is thought to cause tumor hypoxia and increase resistance to therapy. In glioma patients, we tested whether perfusion-weighted MRI (PWI) based indices of microvascular flow control provide more information on tumor grade and patient outcome...... than does the established PWI angiogenesis marker, cerebral blood volume (CBV). Material and Methods: Seventy-two glioma patients (sixty high-grade, twelve low-grade gliomas) were included. Capillary transit time heterogeneity (CTH) and COV, its ratio to blood mean transit time, provide indices...... of microvascular flow control and the extent to which oxygen can be extracted by tumor tissue. The ability of these parameters and CBV to differentiate tumor grade were assessed by receiver operating characteristic curves and logistic regression. Their ability to predict time to progression and overall survival...

Effect of high and low ultrafiltration volume during hemodialysis on relative blood volume

NARCIS (Netherlands)

Dasselaar, JJ; de Jong, PE; Huisman, RM; Franssen, CFM

2006-01-01

Achieving an optimal posthemodialysis hydration status may be difficult because objective criteria for dry weight are lacking. Both relative blood volume changes (Delta RBV) at the end of hemodialysis and Delta RBV normalized for ultrafiltration volume (Delta RBV/UF ratio) have been reported to

High-grade and low-grade gliomas: differentiation by using perfusion MR imaging

International Nuclear Information System (INIS)

Hakyemez, B.; Erdogan, C.; Ercan, I.; Ergin, N.; Uysal, S.; Atahan, S.

2005-01-01

AIM: Relative cerebral blood volume (rCBV) is a commonly used perfusion magnetic resonance imaging (MRI) technique for the evaluation of tumour grade. Relative cerebral blood flow (rCBF) has been less studied. The goal of our study was to determine the usefulness of these parameters in evaluating the histopathological grade of the cerebral gliomas. METHODS: This study involved 33 patients (22 high-grade and 11 low-grade glioma cases). MRI was performed for all tumours by using a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence followed by conventional MRI. The rCBV and rCBF were calculated by deconvolution of an arterial input function. The rCBV and rCBF ratios of the lesions were obtained by dividing the values obtained from the normal white matter of the contralateral hemisphere. For statistical analysis Mann-Whitney testing was carried out. A p value of less than 0.05 indicated a statistically significant difference. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBV and rCBF ratios and grade of gliomas. Their cut-off value permitting discrimination was calculated. The correlation between rCBV and CBF ratios and glioma grade was assessed using Pearson correlation analysis. RESULTS: In high-grade gliomas, rCBV and rCBF ratios were measured as 6.50±4.29 and 3.32±1.87 (mean±SD), respectively. In low-grade gliomas, rCBV and rCBF ratios were 1.69±0.51 and 1.16±0.38, respectively. The rCBV and rCBF ratios for high-grade gliomas were statistically different from those of low-grade gliomas (p 0.05). The cut-off value was taken as 1.98 in the rCBV ratio and 1.25 in the rCBF ratio. There was a strong correlation between the rCBV and CBF ratios (Pearson correlation = 0.830, p<0.05). CONCLUSION: Perfusion MRI is useful in the preoperative assessment of the histopathologicalal grade of gliomas; the rCBF ratio in addition to the rCBV ratio can be incorporated

Blood flow and blood volume in the femoral heads of healthy adults according to age. Measurement with positron emission tomography (PET)

International Nuclear Information System (INIS)

Kubo, Toshikazu; Kimori, Kokuto; Nakamura, Fuminori; Inoue, Shigehiro; Fujioka, Mikihiro; Ueshima, Keiichiro; Hirasawa, Yasusuke; Ushijima, Yo; Nishimura, Tsunehiko

2001-01-01

To deepen understanding of hemodynamics in the femoral head, i.e., the essential factor in clarifying pathogenesis of hip disorders, this study examined blood flow and blood volume in the femoral heads of healthy adults, and their changes with age, by using positron emission tomography (PET). In 16 healthy adult males (age: 20-78 years old, mean age: 42 years), blood flow was measured by means of the H 2 15 O dynamic study method, and blood volume was measured by means of the 15 O-labeled carbon monoxide bolus inhalation method. Blood flow was 1.68-6.47 ml/min/100 g (mean ±SD: 3.52±1.2), and blood volume was 1.67-6.03 ml/100 g (mean ±SD: 3.00±1.27). Blood flow significantly decreased (p<0.01) with age, and blood volume significantly increased (P<0.05). PET was useful in the measurement of blood flow and blood volume in the femoral heads. With age, physiological hemodynamic changes also increased in femoral heads. (author)

Effects of passive heating on central blood volume and ventricular dimensions in humans

DEFF Research Database (Denmark)

Crandall, C.G.; Wilson, T.E.; Marving, J.

2008-01-01

Mixed findings regarding the effects of whole-body heat stress on central blood volume have been reported. This study evaluated the hypothesis that heat stress reduces central blood volume and alters blood volume distribution. Ten healthy experimental and seven healthy time control (i.e. non-heat...... stressed) subjects participated in this protocol. Changes in regional blood volume during heat stress and time control were estimated using technetium-99m labelled autologous red blood cells and gamma camera imaging. Whole-body heating increased internal temperature (> 1.0 degrees C), cutaneous vascular...... conductance (approximately fivefold), and heart rate (52 +/- 2 to 93 +/- 4 beats min(-1)), while reducing central venous pressure (5.5 +/- 07 to 0.2 +/- 0.6 mmHg) accompanied by minor decreases in mean arterial pressure (all P heat stress reduced the blood volume of the heart (18 +/- 2%), heart...

Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

DEFF Research Database (Denmark)

Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

2010-01-01

During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading...... of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males...... from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole...

Plasma volume changes during hypoglycaemia: the effect of arterial blood sampling

DEFF Research Database (Denmark)

Hilsted, J; Bendtsen, F; Christensen, N J

1990-01-01

To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... hypoglycaemia. The magnitude of the changes in arterial and venous blood were not significantly different. These results indicate that the above changes in blood volume and composition are whole-body phenomena: furthermore, the major part of the changes are likely to occur in tissues other than upper extremity...

The role of dynamic susceptibility contrast-enhanced perfusion MR imaging in differentiating between infectious and neoplastic focal brain lesions: results from a cohort of 100 consecutive patients.

Directory of Open Access Journals (Sweden)

Valdeci Hélio Floriano

Full Text Available BACKGROUND AND PURPOSE: Differentiating between infectious and neoplastic focal brain lesions that are detected by conventional structural magnetic resonance imaging (MRI may be a challenge in routine practice. Brain perfusion-weighted MRI (PWI may be employed as a complementary non-invasive tool, providing relevant data on hemodynamic parameters, such as the degree of angiogenesis of lesions. We aimed to employ dynamic susceptibility contrast-enhanced perfusion MR imaging (DSC-MRI to differentiate between infectious and neoplastic brain lesions by investigating brain microcirculation changes. MATERIALS AND METHODS: DSC-MRI perfusion studies of one hundred consecutive patients with non-cortical neoplastic (n = 54 and infectious (n = 46 lesions were retrospectively assessed. MRI examinations were performed using a 1.5-T scanner. A preload of paramagnetic contrast agent (gadolinium was administered 30 seconds before acquisition of dynamic images, followed by a standard dose 10 seconds after starting imaging acquisitions. The relative cerebral blood volume (rCBV values were determined by calculating the regional cerebral blood volume in the solid areas of lesions, normalized to that of the contralateral normal-appearing white matter. Discriminant analyses were performed to determine the cutoff point of rCBV values that would allow the differentiation of neoplastic from infectious lesions and to assess the corresponding diagnostic performance of rCBV when using this cutoff value. RESULTS: Neoplastic lesions had higher rCBV values (4.28±2.11 than infectious lesions (0.63±0.49 (p<0.001. When using an rCBV value <1.3 as the parameter to define infectious lesions, the sensitivity of the method was 97.8% and the specificity was 92.6%, with a positive predictive value of 91.8%, a negative predictive value of 98.0%, and an accuracy of 95.0%. CONCLUSION: PWI is a useful complementary tool in distinguishing between infectious and neoplastic brain

Correlation of diffusion and perfusion MRI with Ki-67 in high-grade meningiomas.

Science.gov (United States)

Ginat, Daniel T; Mangla, Rajiv; Yeaney, Gabrielle; Wang, Henry Z

2010-12-01

Atypical and anaplastic meningiomas have a greater likelihood of recurrence than benign meningiomas. The risk for recurrence is often estimated using the Ki-67 labeling index. The purpose of this study was to determine the correlation between Ki-67 and regional cerebral blood volume (rCBV) and between Ki-67 and apparent diffusion coefficient (ADC) in atypical and anaplastic meningiomas. A retrospective review of the advanced imaging and immunohistochemical characteristics of atypical and anaplastic meningiomas was performed. The relative minimum ADC, relative maximum rCBV, and specimen Ki-67 index were measured. Pearson's correlation was used to compare these parameters. There were 23 cases with available ADC maps and 20 cases with available rCBV maps. The average Ki-67 among the cases with ADC maps and rCBV maps was 17.6% (range, 5-38%) and 16.7% (range, 3-38%), respectively. The mean minimum ADC ratio was 0.91 (SD, 0.26) and the mean maximum rCBV ratio was 22.5 (SD, 7.9). There was a significant positive correlation between maximum rCBV and Ki-67 (Pearson's correlation, 0.69; p = 0.00038). However, there was no significant correlation between minimum ADC and Ki-67 (Pearson's correlation, -0.051; p = 0.70). Maximum rCBV correlated significantly with Ki-67 in high-grade meningiomas.

Differential effects of lower body negative pressure and upright tilt on splanchnic blood volume

Science.gov (United States)

Taneja, Indu; Moran, Christopher; Medow, Marvin S.; Glover, June L.; Montgomery, Leslie D.; Stewart, Julian M.

2015-01-01

Upright posture and lower body negative pressure (LBNP) both induce reductions in central blood volume. However, regional circulatory responses to postural changes and LBNP may differ. Therefore, we studied regional blood flow and blood volume changes in 10 healthy subjects undergoing graded lower-body negative pressure (−10 to −50 mmHg) and 8 subjects undergoing incremental head-up tilt (HUT; 20°, 40°, and 70°) on separate days. We continuously measured blood pressure (BP), heart rate, and regional blood volumes and blood flows in the thoracic, splanchnic, pelvic, and leg segments by impedance plethysmography and calculated regional arterial resistances. Neither LBNP nor HUT altered systolic BP, whereas pulse pressure decreased significantly. Blood flow decreased in all segments, whereas peripheral resistances uniformly and significantly increased with both HUT and LBNP. Thoracic volume decreased while pelvic and leg volumes increased with HUT and LBNP. However, splanchnic volume changes were directionally opposite with stepwise decreases in splanchnic volume with LBNP and stepwise increases in splanchnic volume during HUT. Splanchnic emptying in LBNP models regional vascular changes during hemorrhage. Splanchnic filling may limit the ability of the splanchnic bed to respond to thoracic hypovolemia during upright posture. PMID:17085534

Long-term evolution of cerebral hemodynamics after brain irradiation in the rat

International Nuclear Information System (INIS)

Keyeux, A.; Ochrymowicz-Bemelmans, D.

1985-01-01

Long-term evolution of radioisotope indices, evaluating respectively the cerebral blood flow (CBF), the cerebral blood volume (CBV) and the cephalic specific distribution space of iodoantipyrine (ΔIAP) of rat, was studied after brain irradiation at 20 Gy. Radioinduced hemodynamic alterations evidenced by this approach are biphasic and support the prominent role of circulation impairment in the genesis of delayed brain radionecrosis [fr

Neurovascular coupling to D2/D3 dopamine receptor occupancy using simultaneous PET/functional MRI

DEFF Research Database (Denmark)

Sander, Christin Y; Hooker, Jacob M; Catana, Ciprian

2013-01-01

This study employed simultaneous neuroimaging with positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to demonstrate the relationship between changes in receptor occupancy measured by PET and changes in brain activity inferred by fMRI. By administering the D2/D3...... dopamine receptor antagonist [(11)C]raclopride at varying specific activities to anesthetized nonhuman primates, we mapped associations between changes in receptor occupancy and hemodynamics [cerebral blood volume (CBV)] in the domains of space, time, and dose. Mass doses of raclopride above tracer levels...... caused increases in CBV and reductions in binding potential that were localized to the dopamine-rich striatum. Moreover, similar temporal profiles were observed for specific binding estimates and changes in CBV. Injection of graded raclopride mass doses revealed a monotonic coupling between neurovascular...

SPECT measurements of cerebral blood volume before and after acetazolamide in occlusive cerebrovascular diseases

International Nuclear Information System (INIS)

Inoue, Yusuke; Momose, Toshimitsu; Machida, Kikuo; Honda, Norinari; Nishikawa, Junichi; Sasaki, Yasuhito.

1994-01-01

Cerebral blood volume before and after acetazolamide was measured by SPECT to evaluate cerebral vasodilatory capacity in eight patients with cerebrovascular disease and five control subjects. Two SPECT measurements were performed serially, and acetazolamide was administered between them. The ratio of increase in hemispheric blood volume was calculated, and it was compared with the results of cerebral blood flow and cerebral blood volume measurements. A cerebral vasodilatory capacity map, the image after acetazolamide minus the baseline image, was also produced. Acetazolamide increased hemispheric blood volume in all subjects. The ratio of increase was lower in the involved hemispheres of the patients with unilateral carotid disease than in the uninvolved hemispheres of the patients and control subjects. The ratio of concordance with blood flow and blood volume measurements was approximated at 80%. Cerebral vasodilatory capacity mapping revealed three defects compatible with the clinical data. SPECT measurements of cerebral blood volume after acetazolamide can be performed following baseline SPECT with no additional radiotracer, and may be helpful to assess hemodynamic status. (author)

Radionuclide determined pulmonary blood volume in ischaemic heart disease

International Nuclear Information System (INIS)

Hannan, W.J.; Vojacek, J.; Connell, H.M. Dewhurst N.G.; Muir, A.L.

1981-01-01

Most measurements of pulmonary blood volume have been based on the Stewart-Hamilton dye dilution principle and have required direct catheterisation of the cardiac chambers. Alternatively a precordial counter may be used to detect the composite right and left heart curves after an intravenous injection of radionuclide. We investigated the use of a gamma camera/computer system to determine the radionuclide (sup(99m)Tc) dilution curves from individual cardiac chambers. Pulmonary transit time and pulmonary blood volume were measured in nine normal subjects, eight patients with angina pectoris but without heart failure, and 13 patients with ischaemic heart disease and left ventricular failure. Patients with heart failure had significantly greater (p 0 angle. A reduction in pulmonary blood volume in the tilted position was observed in each subject (p < 0.005). This simple non-invasive measurement should allow more detailed assessment of physiological or pharmacological changes of the pulmonary vascular bed. (author)

Vasomotor origin of intracranial pressure waves in hydrocephalic infants

Energy Technology Data Exchange (ETDEWEB)

Barritault, L; Rimbert, J N; Hirsch, J F; Pierr-Kahn, A; Lacombe, J; Zouaoui, A; Mises, J; Gabersek, V

1980-12-01

By measuring cerebral blood volume (CBV) and intracranial pressure (ICP) variations at the same running time during sleep, it has been demonstrated that the ICP wave which appears during the REM sleep in hydrocephalic infants is produced by intracerebral vaso-dilatation. Nine infants with stabilized hydrocephalus were investigated by non-invasive means: REM phases were distinguished with the usual polysomnographic electrodes. Intracranial pressure was measured with a fontanel palpation transducer and CBV variations were obtained by recording /sup 99/sup(m)Tc activity at the head level after in vivo labelling of red cells with /sup 99/sup(m)Tc-pertechnetate. The time activity curves, obtained from regions of interest and selected on the sequential radioisotope images, show that an increased ICP wave, occurring during the REM period, is related to a simultaneous increase in the blood volume, limited to the cerebral sector and not to the area of the external carotid artery.

Blood and plasma volumes in normal west African dwarf sheep ...

African Journals Online (AJOL)

Blood and plasma volumes were determined using T-1824 in 36 normal adult West African Dwarf sheep. In the rams, dry ewes, pregnant ewes and lactating ewes, the mean values for the blood volume (ml/kg body weight) were 64.08 ± 6.11, 55.74 ± 9.31, 71.46 ± 6.46 and 147.12 ± 12.79 respectively, while the mean values ...

Evaluation of dynamic contrast-enhanced T1-weighted perfusion MRI in the differentiation of tumor recurrence from radiation necrosis

DEFF Research Database (Denmark)

Larsen, Anne Vibeke Andrée; Simonsen, Helle J; Law, Ian

2013-01-01

INTRODUCTION: To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. METHODS: The study was approved by the institutional review board...... to measure cerebral blood volume (CBV), blood-brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used...... to determine whether lesions were regressing or progressing. RESULTS: Fourteen enhancing lesions could be classified as progressing (11) or regressing (three). An empirical threshold of 2.0 ml/100 g for CBV allowed detection of regressing lesions with a sensitivity of 100 % and specificity of 100 %. FDG-PET...

Extracellular space, blood volume, and the early dumping syndrome after total gastrectomy

Energy Technology Data Exchange (ETDEWEB)

Miholic, J.; Reilmann, L.; Meyer, H.J.; Koerber, H.K.; Kotzerke, J.; Hecker, H. (Medzinische Hochschule Hannover (Germany, F.R.))

1990-10-01

Extracellular space and blood volume were measured using 82Br dilution and 51Cr-tagged erythrocytes in 24 tumor-free patients after total gastrectomy. Eleven of the patients suffered from early dumping. Age, blood volume, and extracellular space were significantly smaller in dumpers (P less than 0.05). The dumping score could be predicted by a multiple regression model considering blood volume per lean body mass and extracellular space (r = 0.637; P = 0.0039). Rapid (t1/2 less than 360 seconds) emptying of the gastric substitute, assessed using a 99Tc-labeled solid test meal, was significantly associated with dumping in addition to extracellular space and blood volume (r = 0.876; P = 0.0018). Both rapid emptying and a narrow extracellular space seem to contribute to the early dumping syndrome.

Post-treatment changes of tumour perfusion parameters can help to predict survival in patients with high-grade astrocytoma

Energy Technology Data Exchange (ETDEWEB)

Sanz-Requena, Roberto; Marti-Bonmati, Luis [Hospital Quironsalud Valencia, Radiology Department, Valencia (Spain); Hospital Universitari i Politecnic La Fe, Grupo de Investigacion Biomedica en Imagen, Valencia (Spain); Revert-Ventura, Antonio J.; Salame-Gamarra, Fares [Hospital de Manises, Radiology Department, Manises (Spain); Garcia-Marti, Gracian [Hospital Quironsalud Valencia, Radiology Department, Valencia (Spain); Hospital Universitari i Politecnic La Fe, Grupo de Investigacion Biomedica en Imagen, Valencia (Spain); CIBER-SAM, Instituto de Salud Carlos III, Madrid (Spain); Perez-Girbes, Alexandre [Hospital Universitari i Politecnic La Fe, Grupo de Investigacion Biomedica en Imagen, Valencia (Spain); Molla-Olmos, Enrique [Hospital La Ribera, Radiology Department, Alzira (Spain)

2017-08-15

Vascular characteristics of tumour and peritumoral volumes of high-grade gliomas change with treatment. This work evaluates the variations of T2*-weighted perfusion parameters as overall survival (OS) predictors. Forty-five patients with histologically confirmed high-grade astrocytoma (8 grade III and 37 grade IV) were included. All patients underwent pre- and post-treatment T2*-weighted contrast-enhanced magnetic resonance (MR) imaging. Tumour, peritumoral and control volumes were segmented. Relative variations of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), K{sup trans-T2*}, k{sub ep-T2*}, v{sub e-T2*} and v{sub p-T2*} were calculated. Differences regarding tumour grade and surgical resection extension were evaluated with ANOVA tests. For each parameter, two groups were defined by non-supervised clusterisation. Survival analysis were performed on these groups. For the tumour region, the 90th percentile increase or stagnation of CBV was associated with shorter survival, while a decrease related to longer survival (393 ± 189 vs 594 ± 294 days; log-rank p = 0.019; Cox hazard-ratio, 2.31; 95% confidence interval [CI], 1.12-4.74). K{sup trans-T2*} showed similar results (414 ± 177 vs 553 ± 312 days; log-rank p = 0.037; hazard-ratio, 2.19; 95% CI, 1.03-4.65). The peritumoral area values showed no relationship with OS. Post-treatment variations of the highest CBV and K{sup trans-T2*} values in the tumour volume are predictive factors of OS in patients with high-grade gliomas. (orig.)

Relation of mean platelet volume and red blood cell distribution width with epistaxis.

Science.gov (United States)

Kemal, Ozgur; Müderris, Togay; Sevil, Ergün; Kutlar, Gökhan

2015-04-01

Mean platelet volume is the measurement of the average size of platelets in the blood, and red blood cell distribution width is the variability of the size of red blood cells in circulation. This study aimed to investigate if there was any relationship between mean platelet volume, red blood cell distribution, and epistaxis. Prospective controlled trial. The study included 90 patients admitted to Ankara Atatürk Hospital and Samsun Medicana Hospital with complaints of recurrent epistaxis, and a control group of 90 healthy subjects. Blood samples were taken from all patients and control group subjects. Mean platelet volume and red blood cell distribution parameters were examined and compared between the two groups. The mean platelet volume levels were determined as 8.86 ± 0.1 in the control group and 8.36 ± 0.1 in the patient group. The difference between the two groups with respect to mean platelet volume was statistically significant (P epistaxis. These findings could be beneficial in new investigations into epistaxis mechanisms. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

The analysis of the contrast enhanced lesions on cerebro-vascular diseases

International Nuclear Information System (INIS)

Terada, Tomoaki; Nishiguchi, Takashi; Hyoutani, Genhachi; Miyamoto, Kazuki; Komai, Norihiko

1989-01-01

The contrast enhancement of cerebro-vascular diseases on CT is thought to be due to the increase of the cerebral blood volume (CBV) and/or the disruption of the blood brain barrier (BBB). However, it is difficult to differentiate these two conditions only by contrast enhanced CT. We employed dynamic CT (DCT) to analyse these lesions with respect to the patterns of time-density curve and peak height (PH) of the curve upon the theoretical basis that flattening of the latter part of the time-density curve reflected the degree of BBB disruption and PH reflected the CBV. In all cases of hypertensive intracerebral hemorrhage (11 cases), the contrast enhanced lesion around the hematoma showed marked BBB disruption according to the results of DCT. In 11 cases of cerebral infarction, patterns of BBB disruption and CBV varied at the contrast enhanced lesions according to the result of DCT. However, all contrast enhanced lesions with increased PH were associated with hemorrhagic infarction. Thus, the precise analysis of DCT provides appropriate therapeutic schedules by predicting the occurrence of hemorrhagic infarction. (author)

Quantitative perfusion computed tomography measurements of cerebral hemodynamics: Correlation with digital subtraction angiography identified primary and secondary cerebral collaterals in internal carotid artery occlusive disease

International Nuclear Information System (INIS)

Cheng Xiaoqing; Tian Jianming; Zuo Changjing; Liu Jia; Zhang Qi; Lu Guangming

2012-01-01

Background: The aim of the present study was to assess hemodynamic variations in symptomatic unilateral internal carotid artery occlusion (ICAO) patients with primary collateral flow via circle of Willis or secondary collateral flow via ophthalmic artery and/or leptomeningeal collaterals. Methods: Thirty-eight patients with a symptomatic unilateral ICAO were enrolled in the study. Based on digital subtraction angiography (DSA) findings, patients were classified into 2 groups: primary collateral (n = 14) and secondary collateral (n = 24) groups. Collateral flow hemodynamics were investigated with perfusion computed tomography (PCT) by measuring the cerebral blood flow (CBF), cerebral blood volume (CBV) and time to peak (TTP) in the hemispheres ipsilateral and contralateral to ICAO. Based on the measurements, the ipsilateral to contralateral ratio for each parameter was calculated and compared. Results: Irrespective of the collateral patterns, ipsilateral CBF was not significantly different from that of the contralateral hemisphere (P = 0.285); ipsilateral CBV and TTP was significantly increased compared with those of the contralateral hemisphere (P = 0.000 and P = 0.000 for CBV and TTP, respectively). Furthermore, patients with secondary collaterals had significantly larger ipsilateral-to-contralateral ratios for both CBV (rCBV, P = 0.0197) and TTP (rTTP, P = 0.000) than those of patients with only primary collaterals. These two groups showed no difference in ipsilateral-to-contralateral ratio for CBF (rCBF, P = 0.312). Conclusion: Patients with symptomatic unilateral ICAO in our study were in an autoregulatory vasodilatation status. Moreover, secondary collaterals in ICAO patients were correlated with ipsilateral CBV and delayed TTP that suggested severe hemodynamic impairment, presumably increasing the risk of ischemic events.

Pulmonary blood volume and transit time in cirrhosis: relation to lung function

DEFF Research Database (Denmark)

Møller, Søren; Burchardt, H; Øgard, CG

2006-01-01

BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis......, in the controls, Pvolume...

Beta-1 vs. beta-2 adrenergic control of coronary blood flow during isometric handgrip exercise in humans.

Science.gov (United States)

Maman, Stephan R; Vargas, Alvaro F; Ahmad, Tariq Ali; Miller, Amanda J; Gao, Zhaohui; Leuenberger, Urs A; Proctor, David N; Muller, Matthew D

2017-08-01

During exercise, β-adrenergic receptors are activated throughout the body. In healthy humans, the net effect of β-adrenergic stimulation is an increase in coronary blood flow. However, the role of vascular β1 vs. β2 receptors in coronary exercise hyperemia is not clear. In this study, we simultaneously measured noninvasive indexes of myocardial oxygen supply (i.e., blood velocity in the left anterior descending coronary artery; Doppler echocardiography) and demand [i.e., rate pressure product (RPP) = heart rate × systolic blood pressure) and tested the hypothesis that β1 blockade with esmolol improves coronary exercise hyperemia compared with nonselective β-blockade with propranolol. Eight healthy young men received intravenous infusions of esmolol, propranolol, and saline on three separate days in a single-blind, randomized, crossover design. During each infusion, subjects performed isometric handgrip exercise until fatigue. Blood pressure, heart rate, and coronary blood velocity (CBV) were measured continuously, and RPP was calculated. Changes in parameters from baseline were compared with paired t -tests. Esmolol (Δ = 3296 ± 1204) and propranolol (Δ = 2997 ± 699) caused similar reductions in peak RPP compared with saline (Δ = 5384 ± 1865). In support of our hypothesis, ΔCBV with esmolol was significantly greater than with propranolol (7.3 ± 2.4 vs. 4.5 ± 1.6 cm/s; P = 0.002). This effect was also evident when normalizing ΔCBV to ΔRPP. In summary, not only does selective β1 blockade reduce myocardial oxygen demand during exercise, but it also unveils β2-receptor-mediated coronary exercise hyperemia. NEW & NOTEWORTHY In this study, we evaluated the role of vascular β1 vs. β2 receptors in coronary exercise hyperemia in a single-blind, randomized, crossover study in healthy men. In response to isometric handgrip exercise, blood flow velocity in the left anterior descending coronary artery was significantly greater with esmolol compared with

Plasma and blood volume in the calf from birth till 90 days of age

International Nuclear Information System (INIS)

Moellerberg, L.; Ekman, L.; Jacobsson, S.-O.

1975-01-01

Determinations of plasma volume were made of 9 clinically healthy Swedish Red and White calves from birth to 90 days of age by means of the isotop dilution technique. Commercially available 131 I labelled human serum albumin was used. Calculation of the total blood volume was based on the plasma volume and packed cell volume. The plasma and blood volumes increased per kg body weight in average 17 and 14 percent respectively from directly after birth to 24 hrs. old. From 1 to 90 days of age the plasma and blood volume fell steadily per kg body weight. Plasma volume expressed as a percentage of body weight was 5.3 percent at birth, 6.5 percent at 1 day old, and 4.9 percent at 90 days old. Corresponding values for blood were 8.4, 9.3 and 7.0 percent. (author)

blood and plasma volumes in normal west african dwarf sheep

African Journals Online (AJOL)

Dr Olaleye

volume (PCV) and haemoglobin (Hb) values were determined as descried by Benjamin (1978) using the microhaematocrit and ... Standard dye concentration of 20 mg/ml was used for determining the dye concentration in plasma. ... Haemoglobin (Hb), Plasma Volume and Blood Volume in the West African Dwarf. Sheep.

Whole body and tissue blood volumes of two strains of rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Gingerich, W.H.; Pityer, R.A.; Rach, J.J.

1990-01-01

1. Estimates of apparent packed cell, plasma and total blood volumes for the whole body and for 13 selected tissues were compared between Kamloops and Wytheville strains of rainbow trout (Oncorhynchus mykiss) by the simultaneous injection of two vascular tracers, radiolabeled trout erythrocytes (51Cr-RBC) and radioiodated bovine serum albumin (125I-BSA).2. Whole body total blood volume, plasma volume and packed cell volume were slightly, but not significantly greater in the Wytheville trout, whereas, the apparent plasma volumes and total blood volumes in 4 of 13 tissues were significantly greater in the Kamloops strain.3. Differences were most pronounced in highly perfused organs, such as the liver and kidney and in organs of digestion such as the stomach and intestines.4. Differences in blood volumes between the two strains may be related to the greater permeability of the vascular membranes in the Kamloops strain fish.

Support Vector Machine Based Monitoring of Cardio-Cerebrovascular Reserve during Simulated Hemorrhage.

Science.gov (United States)

van der Ster, Björn J P; Bennis, Frank C; Delhaas, Tammo; Westerhof, Berend E; Stok, Wim J; van Lieshout, Johannes J

2017-01-01

Introduction: In the initial phase of hypovolemic shock, mean blood pressure (BP) is maintained by sympathetically mediated vasoconstriction rendering BP monitoring insensitive to detect blood loss early. Late detection can result in reduced tissue oxygenation and eventually cellular death. We hypothesized that a machine learning algorithm that interprets currently used and new hemodynamic parameters could facilitate in the detection of impending hypovolemic shock. Method: In 42 (27 female) young [mean (sd): 24 (4) years], healthy subjects central blood volume (CBV) was progressively reduced by application of -50 mmHg lower body negative pressure until the onset of pre-syncope. A support vector machine was trained to classify samples into normovolemia (class 0), initial phase of CBV reduction (class 1) or advanced CBV reduction (class 2). Nine models making use of different features were computed to compare sensitivity and specificity of different non-invasive hemodynamic derived signals. Model features included : volumetric hemodynamic parameters (stroke volume and cardiac output), BP curve dynamics, near-infrared spectroscopy determined cortical brain oxygenation, end-tidal carbon dioxide pressure, thoracic bio-impedance, and middle cerebral artery transcranial Doppler (TCD) blood flow velocity. Model performance was tested by quantifying the predictions with three methods : sensitivity and specificity, absolute error, and quantification of the log odds ratio of class 2 vs. class 0 probability estimates. Results: The combination with maximal sensitivity and specificity for classes 1 and 2 was found for the model comprising volumetric features (class 1: 0.73-0.98 and class 2: 0.56-0.96). Overall lowest model error was found for the models comprising TCD curve hemodynamics. Using probability estimates the best combination of sensitivity for class 1 (0.67) and specificity (0.87) was found for the model that contained the TCD cerebral blood flow velocity derived

Support Vector Machine Based Monitoring of Cardio-Cerebrovascular Reserve during Simulated Hemorrhage

Directory of Open Access Journals (Sweden)

Björn J. P. van der Ster

2018-01-01

Full Text Available Introduction: In the initial phase of hypovolemic shock, mean blood pressure (BP is maintained by sympathetically mediated vasoconstriction rendering BP monitoring insensitive to detect blood loss early. Late detection can result in reduced tissue oxygenation and eventually cellular death. We hypothesized that a machine learning algorithm that interprets currently used and new hemodynamic parameters could facilitate in the detection of impending hypovolemic shock.Method: In 42 (27 female young [mean (sd: 24 (4 years], healthy subjects central blood volume (CBV was progressively reduced by application of −50 mmHg lower body negative pressure until the onset of pre-syncope. A support vector machine was trained to classify samples into normovolemia (class 0, initial phase of CBV reduction (class 1 or advanced CBV reduction (class 2. Nine models making use of different features were computed to compare sensitivity and specificity of different non-invasive hemodynamic derived signals. Model features included: volumetric hemodynamic parameters (stroke volume and cardiac output, BP curve dynamics, near-infrared spectroscopy determined cortical brain oxygenation, end-tidal carbon dioxide pressure, thoracic bio-impedance, and middle cerebral artery transcranial Doppler (TCD blood flow velocity. Model performance was tested by quantifying the predictions with three methods: sensitivity and specificity, absolute error, and quantification of the log odds ratio of class 2 vs. class 0 probability estimates.Results: The combination with maximal sensitivity and specificity for classes 1 and 2 was found for the model comprising volumetric features (class 1: 0.73–0.98 and class 2: 0.56–0.96. Overall lowest model error was found for the models comprising TCD curve hemodynamics. Using probability estimates the best combination of sensitivity for class 1 (0.67 and specificity (0.87 was found for the model that contained the TCD cerebral blood flow velocity

Hemodynamic and ADH responses to central blood volume shifts in cardiac-denervated humans

Science.gov (United States)

Convertino, V. A.; Thompson, C. A.; Benjamin, B. A.; Keil, L. C.; Savin, W. M.; Gordon, E. P.; Haskell, W. L.; Schroeder, J. S.; Sandler, H.

1990-01-01

Hemodynamic responses and antidiuretic hormone (ADH) were measured during body position changes designed to induce blood volume shifts in ten cardiac transplant recipients to assess the contribution of cardiac and vascular volume receptors in the control of ADH secretion. Each subject underwent 15 min of a control period in the seated posture, then assumed a lying posture for 30 min at 6 deg head down tilt (HDT) followed by 20 min of seated recovery. Venous blood samples and cardiac dimensions (echocardiography) were taken at 0 and 15 min before HDT, 5, 15, and 30 min of HDT, and 5, 15, and 30 min of seated recovery. Blood samples were analyzed for hematocrit, plasma osmolality, plasma renin activity (PRA), and ADH. Resting plasma volume (PV) was measured by Evans blue dye and percent changes in PV during posture changes were calculated from changes in hematocrit. Heart rate (HR) and blood pressure (BP) were recorded every 2 min. Results indicate that cardiac volume receptors are not the only mechanism for the control of ADH release during acute blood volume shifts in man.

Intracranial hemodynamics during intravenous infusion of glyceryl trinitrate

DEFF Research Database (Denmark)

Iversen, H.K.; Holm, S.; Friberg, L.

2008-01-01

The mechanisms of glyceryl trinitrate (GTN)-induced headache are not fully elucidated. In this study we administered GTN 0.5 microg/kg/min i.v. for 20 min in six healthy volunteers. Before, during and 60 min after the infusion, we investigated regional cerebral blood flow (rCBF), cerebral blood...... volume (CBV), both estimated with SPECT, and blood flow velocity (BFV) in the middle cerebral artery (MCA), measured with transcranial Doppler. Headache was scored on a numerical verbal rating (0-10) scale. rCBF was unchanged, CBV was slightly increased (13%) during GTN infusion, whereas BFV decreased...... both during (20%) and 60 min (15%) after GTN. Headache was short-lived and maximal during infusion. This discrepancy of time-effect curves for the effect of GTN on headache and dilatation of MCA indicates that MCA is most likely not the primary source of pain in GTN-induced headache. The time...

Volume of blood suctioned during vacuum-assisted breast biopsy predicts later hematoma formation

Directory of Open Access Journals (Sweden)

Panopoulou Effrosyni

2010-03-01

Full Text Available Abstract Background To evaluate whether the volume of blood suctioned during vacuum-assisted breast biopsy (VABB is associated with hematoma formation and progression, patient's age and histology of the lesion. Findings 177 women underwent VABB according to standardized protocol. The volume of blood suctioned and hematoma formation were noted at the end of the procedure, as did the subsequent development and progression of hematoma. First- and second-order logistic regression was performed, where appropriate. Cases with hematoma presented with greater volume of blood suctioned (63.8 ± 44.7 cc vs. 17.2 ± 32.9 cc; p Conclusion The likelihood of hematoma is increasing along with increasing amount of blood suctioned, reaching a plateau approximately at 80 cc of blood lost.

Exercise induced pulmonary, hepatic and splenic blood volume changes in diabetic subjects

International Nuclear Information System (INIS)

Mubashar, M.

1993-01-01

Exercise induced blood volume changes in visceral organs were determined by scintillation gamma camera imaging in 11 normal healthy male volunteers and 15 NIDDM male diabetics without clinical signs of neuropathy. After in-vivo labelling of red cells with Technetium-99m, the data was acquired in the supine position at rest and immediately after graded upright ergometer bicycle exercise. From rest to peak exercise, pulmonary blood volume increased 19% and 75% in normal volunteers of less than and more than 40 years of age respectively. A decrease of 18% and 42% was noted in the hepatic and splenic blood volume respectively, regardless of the age, in the normal subjects. In contrast to normals, the diabetic patients showed in response to peak exercise as compared to age-matched controls. A significant difference in the drop in pulmonary blood volume 82.37% and 90% was observed between diabetics of more than and less than 7 years duration respectively. The liver and spleen of the diabetic subjects revealed a lesser decrease of 87.6% and 71.33% respectively in response to peak stress in comparison to the age matched controls. The reduction in the hepatic and splenic blood volume was equally evident in diabetics of more than or less than 50 years of age and it was statistically nonsignificant. This study demonstrates that the normal pattern of redistribution of blood volume in response to maximum exercise in diabetics is altered such that there is restricted pulmonary perfusion and diminished vasoconstriction of the hepato splenic vascular bed and the changes in the pulmonary circulation are related to the duration of the diabetics rather than the age of the patient. (author)

Characterization of glial tumors in PET/CT 18F-dopa and in perfusion MRI

International Nuclear Information System (INIS)

Nioche, Christophe

2011-01-01

MRI provides morphological information about a tumour, as well as information regarding its micro-vascularisation of the tumour. In PET/CT, accumulation of 18 F-Dopa in tumour cells results from the metabolic activity greater than that of healthy tissues.We studied 28 gliomas for which we analysed data from MRI and PET/CT. A registration method has been developed to combine information from both PET and MRI and to extract volumes of interest consistent with the information included in the two modalities. In these volumes, the tumour compartment and normal tissue compartment were identified using a Gaussian mixture model. Parameters from PET or MRI data were then calculated in these compartments. ROC analyses combined with linear discriminant analyses were used to assess whether joint observation of standardized uptake value (SUVmax) and relative Cerebral Blood Volume (rCBV) or of relative rk1 and rCBV could distinguish between low grade and high grade tumours. We found that using this joint analysis, 82% of high-grade tumors and 70% of low grade tumors were correctly classified (AUC of 0.88 for [SUVmax, rCBV] and of 0.92 for [rk1, rCBV]). Considering the combined information from [SUVmax, rCBV], the sensitivity for detecting high-grade tumors was 95% with a specificity of 60%. The negative predictive value was 52% for a positive predictive value of 95%. Similarly, considering the combined information from [rk1, rCBV], we also obtain a specificity of 60% associated with a 95% sensitivity for detecting high-grade tumors, with a negative predictive value of 60% and positive predictive value of 95%. Our work shows that joint analysis of information from microvascular and metabolic is possible by combining PET and MR imaging data. However, we found that, in our patient population, the microvascular information obtained through MR did not achieve better discrimination than the metabolic information derived from PET only. (author)

Relative blood volume monitoring during hemodialysis in end stage renal disease patients.

Science.gov (United States)

Ion Titapiccolo, Jasmine; Ferrario, Manuela; Garzotto, Francesco; Cruz, Dinna; Moissl, Ulrich; Tetta, Ciro; Ronco, Claudio; Signorini, Maria G; Cerutti, Sergio

2010-01-01

A crucial point in the haemodialysis (HD) treatment is the reliable assessment of hydration status. An inadequate removed volume may lead to chronic fluid overload which can lead to hypertension, left ventricular hypertrophy and heart failure. Therefore, the estimation of the hydration state and the management of a well-tolerated water removal is an important challenge. This exploratory study aims at identifying new parameters obtained from continuous Blood Volume Monitoring (BVM) allowing a qualitative evaluation of hydration status for verifying the adequacy of HD setting parameters (e.g UFR, target dry weight). The percentage of blood volume reduction (BVR%) during HD was compared against a gold standard method for hydration status assessment. The slope of the first 30 minute of blood volume reduction (BVR) was proposed as a useful parameter to identify overhydrated patients.

Global and regional changes of cardiopulmonary blood volume under continuous work load

International Nuclear Information System (INIS)

Hoeck, A.; Schuerch, P.; Freundlieb, C.; Vyska, K.; Kunz, N.; Feinendegen, L.E.; Hollmann, W.

1980-01-01

The present study describes a method for the continuous determination of global and regional stress-induced alterations of cardiopulmonary blood volumes in normals, trained athletes and patients with latent cardiac insufficiency. In contrast to normals and athletes there is an increase of the total cardiac blood volume in the cardiac patients. There are also significant differences in blood volume changes of the left lung between normals and athletes on the one hand and the cardiac patients on the other. The method is simple and non-hazardous; it permits the observation of the obviously different adaptation of the cardiopulmonary system during exercise in normals, athletes and cardiac patients. (orig.) [de

Blood volume determination with two radioisotopes: application to non-cardiogenic shock

International Nuclear Information System (INIS)

Mallet, J.-J.

1975-01-01

Knowledge of the circulating blood volume may be of great assistance in the study of clinical shock. The isotope dilution principle is used to measure both plasma and red cell volume. Considering the increased capillary permeability in patients in shock, it may be of considerable value to quantify the diffusion of liquid through the capillary walls. A double determination of the volume of distribution of the tracer is to be envisaged. Two methods are described. The first one uses a non-diffusible tracer (sup(99m)Tc-labelled red cells) confined to the intravascular space, giving a measure of the intravascular blood volume. The latter uses 131 I-labelled serum albumin which remains, usually, in the vascular bed, but is able to diffuse through the pores of the capillary membrane, because of its low molecular weight. A resulting increase of the tracer volume distribution, with regard to this capillary diffusion is considered. A comparison of the two methods used simultaneously appear to provide information on the possible liquid diffusion in clinical shock. The results obtained in several pathological conditions are described. They enable conclusion to be drawn on the possibility of errors introduced by the use of 131 I-labelled serum albumin alone in determining the circulating blood volume in clinical shock [fr

Cerebral peritumoral oedema study: Does a single dynamic MR sequence assessing perfusion and permeability can help to differentiate glioblastoma from metastasis?

International Nuclear Information System (INIS)

Lehmann, Pierre; Saliou, Guillaume; Marco, Giovanni de; Monet, Pauline; Souraya, Stoquart-Elsankari; Bruniau, Alexis; Vallée, Jean Noel; Ducreux, Denis

2012-01-01

Our purpose was to differentiate glioblastoma from metastasis using a single dynamic MR sequence to assess perfusion and permeability parameters. 24 patients with glioblastoma or cerebral metastasis with peritumoral oedema were recruited and explored with a 3 T MR unit. Post processing used DPTools software. Regions of interest were drawn around contrast enhancement to assess relative cerebral blood volume and permeability parameters. Around the contrast enhancement Glioblastoma present high rCBV with modification of the permeability, metastasis present slight modified rCBV without modification of permeability. In conclusion, peritumoral T2 hypersignal exploration associating morphological MR and functional MR parameters can help to differentiate cerebral metastasis from glioblastoma.

Determination of left ventricular volume using gated blood pool tomography comparison with contrast ventriculography

International Nuclear Information System (INIS)

Lu Ping; Mo Lijun; Liu Xiujie

1992-01-01

48 patients with cardiac disease were studied with gated blood pool tomography to determine left ventricular volume at end diastole, end-systole and ejection fraction. The volumes were calculated from serial short-axis tomograms by multiplying the number of pixels and the known volume of each pixel. Excellent correlation was found between blood pool tomography and contrast ventriculographic volume. At end-diastole, r = 0.91 (P < 0.01); at end-systole, r = 0.95 (P < 0.01); for left ventricular ejection fraction, r 0.90 (P < 0.01). The results suggest that gated blood pool tomography is a promising noninvasive and direct method for measuring left ventricular volume

Assessment of brain metastases by means of dynamic susceptibility contrast enhanced MRI

International Nuclear Information System (INIS)

Knopp, M.; Wenz, F.; Debus, J.; Hentrich, H.R.

2002-01-01

Full text: To assess if pre therapeutic measurements of regional cerebral blood flow (rCBF) and volume (rCVB) are able to predict the response of brain metastases to radiation therapy and to assess the influence of radiosurgery on rCBF and rCBV on brain metastases and normal surrounding tissue. We examined 25 patients with brain metastases prior to high dose radiosurgery with conventional T1 and T2 weighted MRI and dynamic susceptibility contrast enhanced MRI (DSC MRI). For DSC MRI 55 T2*w GE images of two sections were acquired after bolus administration of 0.1 mmol/kg gadoteridol (ProHance) for the simultaneous measurement of brain feeding arteries and brain tissue. This allowed an absolute quantification of rCBF and rCBV. Follow-up examinations were performed 6 weeks and 3 months after radiotherapy and the acquired perfusion data were related to a 3 point scale of treatment outcome. Radiosurgery was performed by a linear accelerator with a 80% isodose of 18-20 Gv. For treatment planning the heads of the patients were immobilized by a cask mask to avoid head movement. DSC MRI was able to assess perfusion data in all patients. Higher pre therapeutic rCBV seems to predict a poor treatment outcome. After radiosurgery patients with tumor remission and stable disease presented a decrease of rCBV over time regardless of temporary tumor volume increase. Patients with tumor progression at the 3 month followup presented an increase of rCBV. Effects on normal surrounding tissue could not be observed. DSC MRI using Gadoteridol allows the non-invasive assessment of rCBV and rCBF of brain metastases and its changes due to radiosurgery. The method may also be able to predict treatment outcome. Furthermore radiofrequency effects on surrounding unaffected tissue can be monitored. Copyright (2002) Blackwell Science Pty Ltd

Added value of CT perfusion compared to CT angiography in predicting clinical outcomes of stroke patients treated with mechanical thrombectomy

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Tsogkas, Ioannis; Knauth, Michael; Schregel, Katharina; Behme, Daniel; Psychogios, Marios Nikos [University Medicine Goettingen, Department of Neuroradiology, Goettingen (Germany); Wasser, Katrin; Maier, Ilko; Liman, Jan [University Medicine Goettingen, Department of Neurology, Goettingen (Germany)

2016-11-15

CTP images analyzed with the Alberta stroke program early CT scale (ASPECTS) have been shown to be optimal predictors of clinical outcome. In this study we compared two biomarkers, the cerebral blood volume (CBV)-ASPECTS and the CTA-ASPECTS as predictors of clinical outcome after thrombectomy. Stroke patients with thrombosis of the M1 segment of the middle cerebral artery were included in our study. All patients underwent initial multimodal CT with CTP and CTA on a modern CT scanner. Treatment consisted of full dose intravenous tissue plasminogen activator, when applicable, and mechanical thrombectomy. Three neuroradiologists separately scored CTP and CTA images with the ASPECTS score. Sixty-five patients were included. Median baseline CBV-ASPECTS and CTA-ASPECTS for patients with favourable clinical outcome at follow-up were 8 [interquartile range (IQR) 8-9 and 7-9 respectively]. Patients with poor clinical outcome showed a median baseline CBV-ASPECTS of 6 (IQR 5-8, P < 0.0001) and a median baseline CTA-ASPECTS of 7 (IQR 7-8, P = 0.18). Using CBV-ASPECTS and CTA-ASPECTS raters predicted futile reperfusions in 96 % and 56 % of the cases, respectively. CBV-ASPECTS is a significant predictor of clinical outcome in patients with acute ischemic stroke treated with mechanical thrombectomy. (orig.)

Comparison of first-pass and second-bolus dynamic susceptibility perfusion MRI in brain tumors

International Nuclear Information System (INIS)

Spampinato, M.V.; Besenski, Nada; Rumboldt, Zoran; Wooten, Caroline; Dorlon, Margaret

2006-01-01

Our goal was to evaluate whether the T1 shortening effect caused by contrast leakage into brain tumors, a well-known confounding effect in the quantification of relative cerebral blood volume (rCBV) measurements, may be corrected by the administration of a predose of gadolinium-DTPA. As part of their presurgical imaging protocol, 25 patients with primary brain tumors underwent two consecutive dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MR studies. Intratumoral rCBV measurements and normalized rCBV values obtained during the first-pass and second-bolus studies were compared (Wilcoxon signed-ranks test). The frequency of relatively increased rCBV ratios on the second-bolus study was compared between enhancing and non-enhancing neoplasms (Fisher's exact test). Postprocessing perfusion studies were evaluated for image quality on a scale of 0-3 (Wilcoxon signed-ranks test). Four studies were excluded due to unacceptable image quality. Mean normalized rCBVs were 9.04 (SD 4.64) for the first-pass and 7.99 (SD 3.84) for the second-bolus study. There was no statistically significant difference between the two perfusion studies in either intratumoral rCBV (P=0.237) or rCBV ratio (P=0.181). Five enhancing and four non-enhancing tumors showed a relative increase in rCBV ratio on the second-bolus study, without a significant difference between the groups. Image quality was not significantly different between perfusion studies. Our results did not demonstrate a significant difference between first-pass and second-bolus rCBV measurements in DSC perfusion MR imaging. The administration of a predose of gadolinium-DTPA does not appear to be an efficient way of compensating for the underestimation of intratumoral rCBV values due to the T1 shortening effect. (orig.)

Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

International Nuclear Information System (INIS)

Pitkaenen, M.A.; Hopewell, J.W.

1985-01-01

Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

Scintigraphic method for evaluating reductions in local blood volumes in human extremities

DEFF Research Database (Denmark)

Blønd, L; Madsen, Jan Lysgård

2000-01-01

in the experiment. Evaluation of one versus two scintigraphic projections, trials for assessment of the reproducibility, a comparison of the scintigraphic method with a water-plethysmographic method and registration of the fractional reduction in blood volume caused by exsanguination as a result of simple elevation......% in the lower limb experiment and 6% in the upper limb experiment. We found a significant relation (r = 0.42, p = 0.018) between the results obtained by the scintigraphic method and the plethysmographic method. In fractions, a mean reduction in blood volume of 0.49+0.14 (2 SD) was found after 1 min of elevation......We introduce a new method for evaluating reductions in local blood volumes in extremities, based on the combined use of autologue injection of 99mTc-radiolabelled erythrocytes and clamping of the limb blood flow by the use of a tourniquet. Twenty-two healthy male volunteers participated...

Long term evaluation of brain perfusion with magnetic resonance in high flow extracranial-intracranial saphenous graft bypass

Energy Technology Data Exchange (ETDEWEB)

Bozzao, Alessandro [University of Rome La Sapienza, Department of Neuroradiology, II Faculty of Medicine, Rome (Italy); Sant' Andrea Hospital, Rome (Italy); Fasoli, Fabrizio; Finocchi, Vanina; Romano, Andrea; Fantozzi, Luigi M. [University of Rome La Sapienza, Department of Neuroradiology, II Faculty of Medicine, Rome (Italy); Santoro, Giuseppe [University of Rome La Sapienza, Department of Neurosurgery, I Faculty of Medicine, Rome (Italy)

2007-01-15

Assessment was made of the cerebral vascular haemodynamic parameters in patients with a high-flow extra-intracranial (EC-IC) bypass performed for therapeutic occlusion of the internal carotid artery (ICA). Sixteen patients with ICA occlusion and EC-IC bypass (time interval from surgery 1-6 years) underwent MRI. Perfusion-weighted magnetic resonance imaging (PW-MRI) sequences were performed without the use of an arterial input function. The relative cerebral blood volume (rCBV), mean transit time (MTT) and relative cerebral blood flow (rCBF) were evaluated in all patients at the level of the basal ganglia, centrum semiovale and cortex in both hemispheres. Statistically significant differences (P<0.005) were observed in the haemodynamic parameters, indicating increased rCBV in the basal ganglia and decreased rCBF and rCBV in the cortex of the hemisphere supplied by the graft with respect to the contralateral. Patients with occlusion of the ICA and high flow EC-IC bypass do have altered vascular haemodynamic status between the hemispheres. In particular, rCBF is impaired in the surgical hemisphere at the level of the cortex. These patients should be followed-up to rule out chronic ischemia. (orig.)

Reduced microvascular volume and hemispherically deficient vasoreactivity to hypercapnia in acute ischemia: MRI study using permanent middle cerebral artery occlusion rat model.

Science.gov (United States)

Suh, J Y; Shim, Woo H; Cho, Gyunggoo; Fan, Xiang; Kwon, Seon J; Kim, Jeong K; Dai, George; Wang, Xiaoying; Kim, Young R

2015-06-01

Vasoreactivity to hypercapnia has been used for assessing cerebrovascular tone and control altered by ischemic stroke. Despite the high prognostic potential, traits of hypercapnia-induced hemodynamic changes have not been fully characterized in relation with baseline vascular states and brain tissue damage. To monitor cerebrovascular responses, T2- and T2*-weighted magnetic resonance imaging (MRI) images were acquired alternatively using spin- and gradient-echo echo plannar imaging (GESE EPI) sequence with 5% CO2 gas inhalation in normal (n=5) and acute stroke rats (n=10). Dynamic relative changes in cerebrovascular volume (CBV), microvascular volume (MVV), and vascular size index (VSI) were assessed from regions of interest (ROIs) delineated by the percent decrease of apparent diffusion coefficient (ADC). The baseline CBV was not affected by middle cerebral artery occlusion (MCAO) whereas the baseline MVV in ischemic areas was significantly lower than that in the rest of the brain and correlated with ADC. Vasoreactivity to hypercapnic challenge was considerably attenuated in the entire ipsilesional hemisphere including normal ADC regions, in which unsolicited, spreading depression-associated increases of CBV and MVV were observed. The lesion-dependent inhomogeneity in baseline MVV indicates the effective perfusion reserve for accurately delineating the true ischemic damage while the cascade of neuronal depolarization is probably responsible for the hemispherically lateralized changes in overall neurovascular physiology.

Pulmonary blood volume and transit time in cirrhosis: relation to lung function

DEFF Research Database (Denmark)

Møller, Søren; Burchardt, H; Øgard, CG

2006-01-01

BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... in cirrhosis. The relation between PBV and PTT and the low diffusing capacity suggests the pulmonary vascular compartment as an important element in the pathophysiology of the lung dysfunction in cirrhosis....... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis...

Critical Evaluation of Blood Volume Measurements during Hemodialysis

NARCIS (Netherlands)

Dasselaar, Judith J.; van der Sande, Frank M.; Franssen, Casper F. M.

2012-01-01

Devices that continuously measure relative blood volume (RBV) changes during hemodialysis (HD) are increasingly used for the prevention of dialysis hypotension and fine-tuning of dry weight. However, RBV measurements are subject to various limitations. First, RBV devices provide information on

Perfusion magnetic resonance imaging characteristics of intracerebral tuberculomas and its role in differentiating tuberculomas from metastases

Energy Technology Data Exchange (ETDEWEB)

Sankhe, Shilpa; Baheti, Akshay [Dept. of Radiology, Seth GS Medical Coll. and KEM Hospital, Thane (India)], e-mail: akshaybaheti@gmail.com; Ihare, Ashish; Mathur, Shobhit; Dabhade, Poonam; Sarode, Ashish [Dept. of Radiology, Seth GS Medical Coll. and KEM Hospital, Thane (India)

2013-04-15

Background: Intracerebral tuberculomas usually manifest as ring-enhancing of nodular lesions on magnetic resonance imaging (MRI). These imaging findings are also observed in other lesions like metastases and toxoplasmosis. Purpose: To study the MRI perfusion characteristics of tuberculomas and its potential role in their definitive diagnosis. Material and Methods: Thirty-four tuberculomas were evaluated by conventional and perfusion MRI. The relative cerebral blood volume (rCBV) values of the center, peripheral wall, and perilesional neuroparenchymal tissue were calculated using rCBV maps. Ten ring-enhancing metastases were similarly evaluated and rCBV values of their peripheral walls were calculated. Results: Thirty-one of the 34 tuberculomas were ring-enhancing or conglomerate lesions and revealed hypoperfused centers with hyperperfused peripheral walls, with the mean rCBV {+-} SD being 0.42 {+-} 0.25 and 2.04 {+-} 0.61, respectively. Three nodular enhancing lesions showed predominantly homogenous hyperperfusion, with the mean rCBV measuring 2.96 {+-} 0.39 (mean {+-} SD). The perilesional neuroparenchyma was hypoperfused in both cases. The metastases revealed mean rCBV ratio of the peripheral wall to be 5.43 {+-} 2.1 (mean {+-} SD). Analysis of the values by ROC curve method revealed a cut-off value of {>=}3.745 for differentiating ring-enhancing metastases from ring-enhancing tuberculomas. Conclusion: Perfusion MR is a useful tool for the assessment of tuberculomas and can help differentiate them from neoplasms like metastases. It also has a potential role in monitoring therapy and for early detection of drug resistance.

Susceptibility Imaging in Glial Tumor Grading; Using 3 Tesla Magnetic Resonance (MR) System and 32 Channel Head Coil.

Science.gov (United States)

Aydin, Omer; Buyukkaya, Ramazan; Hakyemez, Bahattin

2017-01-01

Susceptibility weighted imaging (SWI) is a velocity compensated, high-resolution three-dimensional (3D) spoiled gradient-echo sequence that uses magnitude and filtered-phase data. SWI seems to be a valuable tool for non-invasive evaluation of central nervous system gliomas. Relative cerebral blood volume (rCBV) ratio is one of the best noninvasive methods for glioma grading. Degree of intratumoral susceptibility signal (ITSS) on SWI correlates with rCBV ratio and histopathological grade. This study investigated the effectiveness of ITSS grading and rCBV ratio in preoperative assessment. Thirty-one patients (17 males and 14 females) with histopathogical diagnosis of glial tumor undergoing routine cranial MRI, SWI, and perfusion MRI examinations between October 2011 and July 2013 were retrospectively enrolled. All examinations were performed using 3T apparatus with 32-channel head coil. We used ITSS number for SWI grading. Correlations between SWI grade, rCBV ratio, and pathological grading were evaluated. ROC analysis was performed to determine the optimal rCBV ratio to distinguish between high-grade and low-grade glial tumors. There was a strong positive correlation between both pathological and SWI grading. We determined the optimal rCBV ratio to discriminate between high-grade and low-grade tumors to be 2.21. In conclusion, perfusion MRI and SWI using 3T MR and 32-channel head coil may provide useful information for preoperative glial tumor grading. SWI can be used as an accessory to perfusion MR technique in preoperative tumor grading.

Variations in gastric emptying of liquid elicited by acute blood volume changes in awake rats

Directory of Open Access Journals (Sweden)

Gondim F. de-A.A.

1998-01-01

Full Text Available We have observed that acute blood volume expansion increases the gastroduodenal resistance to the flow of liquid in anesthetized dogs, while retraction decreases it (Santos et al. (1991 Acta Physiologica Scandinavica, 143: 261-269. This study evaluates the effect of blood volume expansion and retraction on the gastric emptying of liquid in awake rats using a modification of the technique of Scarpignato (1980 (Archives Internationales de Pharmacodynamie et de Therapie, 246: 286-294. Male Wistar rats (180-200 g were fasted for 16 h with water ad libitum and 1.5 ml of the test meal (0.5 mg/ml phenol red solution in 5% glucose was delivered to the stomach immediately after random submission to one of the following protocols: 1 normovolemic control (N = 22, 2 expansion (N = 72 by intravenous infusion (1 ml/min of Ringer-bicarbonate solution, volumes of 1, 2, 3 or 5% body weight, or 3 retraction (N = 22 by controlled bleeding (1.5 ml/100 g. Gastric emptying of liquid was inhibited by 19-51.2% (P<0.05 after blood volume expansion (volumes of 1, 2, 3 or 5% body weight. Blood volume expansion produced a sustained increase in central venous pressure while mean arterial pressure was transiently increased during expansion (P<0.05. Blood volume retraction increased gastric emptying by 28.5-49.9% (P<0.05 and decreased central venous pressure and mean arterial pressure (P<0.05. Infusion of the shed blood 10 min after bleeding reversed the effect of retraction on gastric emptying. These findings suggest that gastric emptying of liquid is subject to modulation by the blood volume.

Computer simulation of preflight blood volume reduction as a countermeasure to fluid shifts in space flight

Science.gov (United States)

Simanonok, K. E.; Srinivasan, R.; Charles, J. B.

1992-01-01

Fluid shifts in weightlessness may cause a central volume expansion, activating reflexes to reduce the blood volume. Computer simulation was used to test the hypothesis that preadaptation of the blood volume prior to exposure to weightlessness could counteract the central volume expansion due to fluid shifts and thereby attenuate the circulatory and renal responses resulting in large losses of fluid from body water compartments. The Guyton Model of Fluid, Electrolyte, and Circulatory Regulation was modified to simulate the six degree head down tilt that is frequently use as an experimental analog of weightlessness in bedrest studies. Simulation results show that preadaptation of the blood volume by a procedure resembling a blood donation immediately before head down bedrest is beneficial in damping the physiologic responses to fluid shifts and reducing body fluid losses. After ten hours of head down tilt, blood volume after preadaptation is higher than control for 20 to 30 days of bedrest. Preadaptation also produces potentially beneficial higher extracellular volume and total body water for 20 to 30 days of bedrest.

21 CFR 864.5950 - Blood volume measuring device.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood volume measuring device. 864.5950 Section 864.5950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices...

Blood volume measurement with indocyanine green pulse spectrophotometry: dose and site of dye administration

NARCIS (Netherlands)

Germans, Menno R.; de Witt Hamer, Philip C.; van Boven, Leonard J.; Zwinderman, Koos A. H.; Bouma, Gerrit J.

2010-01-01

(1) To determine the optimal administration site and dose of indocyanine green (ICG) for blood volume measurement using pulse spectrophotometry, (2) to assess the variation in repeated blood volume measurements for patients after subarachnoid hemorrhage and (3) to evaluate the safety and efficacy of

Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

DEFF Research Database (Denmark)

Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill

2009-01-01

Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... on a pixel-by-pixel basis of cerebral perfusion, cerebral blood volume, and blood-brain barrier permeability.......Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g...

Longitudinal DSC-MRI for Distinguishing Tumor Recurrence From Pseudoprogression in Patients With a High-grade Glioma.

Science.gov (United States)

Boxerman, Jerrold L; Ellingson, Benjamin M; Jeyapalan, Suriya; Elinzano, Heinrich; Harris, Robert J; Rogg, Jeffrey M; Pope, Whitney B; Safran, Howard

2017-06-01

For patients with high-grade glioma on clinical trials it is important to accurately assess time of disease progression. However, differentiation between pseudoprogression (PsP) and progressive disease (PD) is unreliable with standard magnetic resonance imaging (MRI) techniques. Dynamic susceptibility contrast perfusion MRI (DSC-MRI) can measure relative cerebral blood volume (rCBV) and may help distinguish PsP from PD. A subset of patients with high-grade glioma on a phase II clinical trial with temozolomide, paclitaxel poliglumex, and concurrent radiation were assessed. Nine patients (3 grade III, 6 grade IV), with a total of 19 enhancing lesions demonstrating progressive enhancement (≥25% increase from nadir) on postchemoradiation conventional contrast-enhanced MRI, had serial DSC-MRI. Mean leakage-corrected rCBV within enhancing lesions was computed for all postchemoradiation time points. Of the 19 progressively enhancing lesions, 10 were classified as PsP and 9 as PD by biopsy/surgery or serial enhancement patterns during interval follow-up MRI. Mean rCBV at initial progressive enhancement did not differ significantly between PsP and PD (2.35 vs. 2.17; P=0.67). However, change in rCBV at first subsequent follow-up (-0.84 vs. 0.84; P=0.001) and the overall linear trend in rCBV after initial progressive enhancement (negative vs. positive slope; P=0.04) differed significantly between PsP and PD. Longitudinal trends in rCBV may be more useful than absolute rCBV in distinguishing PsP from PD in chemoradiation-treated high-grade gliomas with DSC-MRI. Further studies of DSC-MRI in high-grade glioma as a potential technique for distinguishing PsP from PD are indicated.

Differentiation of grade II/III and grade IV glioma by combining ''T1 contrast-enhanced brain perfusion imaging'' and susceptibility-weighted quantitative imaging

International Nuclear Information System (INIS)

Saini, Jitender; Gupta, Pradeep Kumar; Gupta, Rakesh Kumar; Sahoo, Prativa; Singh, Anup; Patir, Rana; Ahlawat, Suneeta; Beniwal, Manish; Thennarasu, K.; Santosh, Vani

2018-01-01

MRI is a useful method for discriminating low- and high-grade glioma using perfusion MRI and susceptibility-weighted imaging (SWI). The purpose of this study is to evaluate the usefulness of T1-perfusion MRI and SWI in discriminating among grade II, III, and IV gliomas. T1-perfusion MRI was used to measure relative cerebral blood volume (rCBV) in 129 patients with glioma (70 grade IV, 33 grade III, and 26 grade II tumors). SWI was also used to measure the intratumoral susceptibility signal intensity (ITSS) scores for each tumor in these patients. rCBV and ITSS values were compared to seek differences between grade II vs. grade III, grade III vs. grade IV, and grade III+II vs. grade IV tumors. Significant differences in rCBV values of the three grades of the tumors were noted and pairwise comparisons showed significantly higher rCBV values in grade IV tumors as compared to grade III tumors, and similarly increased rCBV was seen in the grade III tumors as compared to grade II tumors (p < 0.001). Grade IV gliomas showed significantly higher ITSS scores on SWI as compared to grade III tumors (p < 0.001) whereas insignificant difference was seen on comparing ITSS scores of grade III with grade II tumors. Combining the rCBV and ITSS resulted in significant improvement in the discrimination of grade III from grade IV tumors. The combination of rCBV values derived from T1-perfusion MRI and SWI derived ITSS scores improves the diagnostic accuracy for discrimination of grade III from grade IV gliomas. (orig.)

Differentiation of grade II/III and grade IV glioma by combining ''T1 contrast-enhanced brain perfusion imaging'' and susceptibility-weighted quantitative imaging

Energy Technology Data Exchange (ETDEWEB)

Saini, Jitender [National Institute of Mental Health and Neurosciences, Neuroimaging and Interventional Radiology, Bangalore (India); Gupta, Pradeep Kumar; Gupta, Rakesh Kumar [Fortis Memorial Research Institute, Department of Radiology and Imaging, Gurugram (India); Sahoo, Prativa [Philips Health System, Philips India Limited, Bangalore (India); Beckman Research Institute, Mathematical Oncology, Duarte, CA (United States); Singh, Anup [Indian Institute of Technology Delhi, Center for Biomedical Engineering, Delhi (India); Patir, Rana [Fortis Memorial Research Institute, Department of Neurosurgery, Gurugram (India); Ahlawat, Suneeta [Fortis Memorial Research Institute, SRL Diagnostics, Gurugram (India); Beniwal, Manish [National Institute of Mental Health and Neurosciences, Department of Neurosurgery, Bangalore (India); Thennarasu, K. [National Institute of Mental Health and Neurosciences, Department of Biostatistics, Bangalore (India); Santosh, Vani [National Institute of Mental Health and Neurosciences, Department of Neuropathology, Bangalore (India)

2018-01-15

MRI is a useful method for discriminating low- and high-grade glioma using perfusion MRI and susceptibility-weighted imaging (SWI). The purpose of this study is to evaluate the usefulness of T1-perfusion MRI and SWI in discriminating among grade II, III, and IV gliomas. T1-perfusion MRI was used to measure relative cerebral blood volume (rCBV) in 129 patients with glioma (70 grade IV, 33 grade III, and 26 grade II tumors). SWI was also used to measure the intratumoral susceptibility signal intensity (ITSS) scores for each tumor in these patients. rCBV and ITSS values were compared to seek differences between grade II vs. grade III, grade III vs. grade IV, and grade III+II vs. grade IV tumors. Significant differences in rCBV values of the three grades of the tumors were noted and pairwise comparisons showed significantly higher rCBV values in grade IV tumors as compared to grade III tumors, and similarly increased rCBV was seen in the grade III tumors as compared to grade II tumors (p < 0.001). Grade IV gliomas showed significantly higher ITSS scores on SWI as compared to grade III tumors (p < 0.001) whereas insignificant difference was seen on comparing ITSS scores of grade III with grade II tumors. Combining the rCBV and ITSS resulted in significant improvement in the discrimination of grade III from grade IV tumors. The combination of rCBV values derived from T1-perfusion MRI and SWI derived ITSS scores improves the diagnostic accuracy for discrimination of grade III from grade IV gliomas. (orig.)

Response Assessment in Neuro-Oncology criteria, contrast enhancement and perfusion MRI for assessing progression in glioblastoma

Energy Technology Data Exchange (ETDEWEB)

Tensaouti, Fatima [Universite de Toulouse, Inserm, UPS, ToNIC, Toulouse NeuroImaging Center, Toulouse (France); Khalifa, Jonathan [Claudius Regaud Institute / Toulouse University Cancer Institute - Oncopole, Department of Radiation Oncology, Toulouse (France); Lusque, Amelie [Claudius Regaud Institute / Toulouse University Cancer Institute - Oncopole, Department of Biostatistics, Toulouse (France); Plas, Benjamin [CHU Toulouse, Department of Neurosurgery, Toulouse (France); Lotterie, Jean Albert; Berry, Isabelle [Universite de Toulouse, Inserm, UPS, ToNIC, Toulouse NeuroImaging Center, Toulouse (France); CHU Toulouse, Department of Nuclear Medicine, Toulouse (France); Laprie, Anne [Universite de Toulouse, Inserm, UPS, ToNIC, Toulouse NeuroImaging Center, Toulouse (France); Claudius Regaud Institute / Toulouse University Cancer Institute - Oncopole, Department of Radiation Oncology, Toulouse (France); Cohen-Jonathan Moyal, Elizabeth [Claudius Regaud Institute / Toulouse University Cancer Institute - Oncopole, Department of Radiation Oncology, Toulouse (France); Toulouse Center for Cancer Research (U1037), Inserm, Toulouse (France); Lubrano, Vincent [Universite de Toulouse, Inserm, UPS, ToNIC, Toulouse NeuroImaging Center, Toulouse (France); CHU Toulouse, Department of Neurosurgery, Toulouse (France)

2017-10-15

The purpose of the study was to evaluate Response Assessment in Neuro-Oncology (RANO) criteria in glioblastoma multiforme (GBM), with respect to the Macdonald criteria and changes in contrast-enhancement (CE) volume. Related variations in relative cerebral blood volume (rCBV) were investigated. Forty-three patients diagnosed between 2006 and 2010 were included. All underwent surgical resection, followed by temozolomide-based chemoradiation. MR images were retrospectively reviewed. Times to progression (TTPs) according to RANO criteria, Macdonald criteria and increased CE volume (CE-3D) were compared, and the percentage change in the 75th percentile of rCBV (rCBV75) was evaluated. After a median follow-up of 22.7 months, a total of 39 patients had progressed according to RANO criteria, 32 according to CE-3D, and 42 according to Macdonald. Median TTPs were 6.4, 9.3, and 6.6 months, respectively. Overall agreement was 79.07% between RANO and CE-3D and 93.02% between RANO and Macdonald. The mean percentage change in rCBV75 at RANO progression onset was over 73% in 87.5% of patients. In conclusion, our findings suggest that CE-3D criterion is not yet suitable to assess progression in routine clinical practice. Indeed, the accurate threshold is still not well defined. To date, in our opinion, early detection of disease progression by RANO combined with advanced MRI imaging techniques like MRI perfusion and diffusion remains the best way to assess disease progression. Further investigations that would examine the impact of treatment modifications after progression determined by different criteria on overall survival would be of great value. (orig.)

Response Assessment in Neuro-Oncology criteria, contrast enhancement and perfusion MRI for assessing progression in glioblastoma

International Nuclear Information System (INIS)

Tensaouti, Fatima; Khalifa, Jonathan; Lusque, Amelie; Plas, Benjamin; Lotterie, Jean Albert; Berry, Isabelle; Laprie, Anne; Cohen-Jonathan Moyal, Elizabeth; Lubrano, Vincent

2017-01-01

The purpose of the study was to evaluate Response Assessment in Neuro-Oncology (RANO) criteria in glioblastoma multiforme (GBM), with respect to the Macdonald criteria and changes in contrast-enhancement (CE) volume. Related variations in relative cerebral blood volume (rCBV) were investigated. Forty-three patients diagnosed between 2006 and 2010 were included. All underwent surgical resection, followed by temozolomide-based chemoradiation. MR images were retrospectively reviewed. Times to progression (TTPs) according to RANO criteria, Macdonald criteria and increased CE volume (CE-3D) were compared, and the percentage change in the 75th percentile of rCBV (rCBV75) was evaluated. After a median follow-up of 22.7 months, a total of 39 patients had progressed according to RANO criteria, 32 according to CE-3D, and 42 according to Macdonald. Median TTPs were 6.4, 9.3, and 6.6 months, respectively. Overall agreement was 79.07% between RANO and CE-3D and 93.02% between RANO and Macdonald. The mean percentage change in rCBV75 at RANO progression onset was over 73% in 87.5% of patients. In conclusion, our findings suggest that CE-3D criterion is not yet suitable to assess progression in routine clinical practice. Indeed, the accurate threshold is still not well defined. To date, in our opinion, early detection of disease progression by RANO combined with advanced MRI imaging techniques like MRI perfusion and diffusion remains the best way to assess disease progression. Further investigations that would examine the impact of treatment modifications after progression determined by different criteria on overall survival would be of great value. (orig.)

Measurement of regional extravascular lung density and of pulmonary blood volume with positron emitting isotopes

Energy Technology Data Exchange (ETDEWEB)

Larock, M.P.; Quaglia, L.; Lamotte, D.; De Landsheere, C.; Del Fiore, G.; Chevigne, M.; Peters, J.M.; Rigo, P. (Universite de Liege (Belgium))

1982-01-01

Studies of pulmonary blood volume changes with exercise can be performed after labelling of the blood pool by /sup 11/CO inhalation. Positron transaxial tomography permits the quantitative study of density distribution of the chest and of the pulmonary blood volume. This paper represents our preliminary experience with these techniques on models and control patients. We have first verified the linearity of transmission for density distribution below one. The tomographic examination first records a transmission image, then an emission image on the same section. We next normalize emission and transmission values on a region of unit density corresponding to blood: then we substract the emission from the transmission values to measure the extravascular pulmonary density. With crystal probes we record pulmonary blood volume variations before, during and after exercise. Peripheral hemodynamic variations explain the change recorded at the begining and at the end of exercise. Combination of these two techniques should help us to better study the importance of the acute changes in the ''formation'' of pulmonary oedema and its influence on regional pulmonary blood volume.

The effect of chronic erythrocytic polycythemia and high altitude upon plasma and blood volumes.

Science.gov (United States)

Burton, R. R.; Smith, A. H.

1972-01-01

Comparison of two kinds of physiological chronic erythrocytic polycythemias in order to differentiate the specific effect of erythrocytic polycythemia from the general effects of high altitude upon the plasma volume. The two kinds were produced hormonally in female chickens, at sea level, or by protracted high-altitude exposures. It appears that the vascular system of the body may account for an increase in red blood cell mass either by reduction in plasma volume, or by no change in plasma volume, resulting in differential changes in total blood volumes.

Correlation of ultrasound estimated placental volume and umbilical cord blood volume in term pregnancy.

Science.gov (United States)

Pannopnut, Papinwit; Kitporntheranunt, Maethaphan; Paritakul, Panwara; Kongsomboon, Kittipong

2015-01-01

To investigate the correlation between ultrasound measured placental volume and collected umbilical cord blood (UCB) volume in term pregnancy. An observational cross-sectional study of term singleton pregnant women in the labor ward at Maha Chakri Sirindhorn Medical Center was conducted. Placental thickness, height, and width were measured using two-dimensional (2D) ultrasound and calculated for placental volume using the volumetric mathematic model. After the delivery of the baby, UCB was collected and measured for its volume immediately. Then, birth weight, placental weight, and the actual placental volume were analyzed. The Pearson's correlation was used to determine the correlation between each two variables. A total of 35 pregnant women were eligible for the study. The mean and standard deviation of estimated placental volume and actual placental volume were 534±180 mL and 575±118 mL, respectively. The median UCB volume was 140 mL (range 98-220 mL). The UCB volume did not have a statistically significant correlation with the estimated placental volume (correlation coefficient 0.15; p=0.37). However, the UCB volume was significantly correlated with the actual placental volume (correlation coefficient 0.62; pcorrelation coefficient 0.38; p=0.02). The estimated placental volume by 2D ultrasound was not significantly correlated with the UCB volume. Further studies to establish the correlation between the UCB volume and the estimated placental volume using other types of placental imaging may be needed.

Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

International Nuclear Information System (INIS)

Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D'Ippolito, Giuseppe; Colleoni, Ramiro

2008-01-01

Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

Energy Technology Data Exchange (ETDEWEB)

Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

2008-09-15

Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

Usefulness of perfusion MR imaging in hyperacute ischemic stroke

International Nuclear Information System (INIS)

Park, Ji Hoon; Kim, Jae Hyoung; Shin, Tae Min; Lee, Eun Ja; Chung, Sung Hoon; Choi, Nack Cheon; Lim, Byeong Hoon; Kim, In One

1998-01-01

Perfusion MR imaging is a new technique for the assessment of acute ischemic stroke. The aim of this study was to evaluate the usefulness of this imaging in hyperacute ischemic stroke in comparison with conventional CT and MR imaging. Eight patients presenting the symptoms of acute ischemic stroke due to middle cerebral artery occlusion were included in this study. Within 2 hours of initial CT scan and 6 hours after the onset of stroke, perfusion MR imaging was performed in all patients using a single-section dynamic contrast-enhanced T2*-weighted imager in conjunction with conventional routine MR imaging and MR angiography. Cerebral blood volume (CBV) maps were then obtained from dynamic MR imaging data by using numerical integration techniques. The findings of CBV maps were compared with those of initial and follow-up CT or MR images. The findings of CBV maps were obviously abnormal in all patients, as compared with normal or focal subtle abnormal findings seen on initial CT and MR images. CBV in the occluded arterial territory was lower in all eight patients;two had focal regions of increased CBV within the affected territory, indicating reperfusion hyperemia. In all patients, regions of abnormal CBV were eventually converted to infarctions on follow-up images. Perfusion MR imaging was useful for the evaluation of hemodynamic change occurring during cerebral perfusion in hyperacute ischemic stroke, and prediction of the final extent of infarction. These results suggest that pertusion MR imaging can play an important role in the diagnosis and management of hyperacute ischemic stroke.=20

Perfusion magnetic resonance imaging characteristics of intracerebral tuberculomas and its role in differentiating tuberculomas from metastases

International Nuclear Information System (INIS)

Sankhe, Shilpa; Baheti, Akshay; Ihare, Ashish; Mathur, Shobhit; Dabhade, Poonam; Sarode, Ashish

2013-01-01

Background: Intracerebral tuberculomas usually manifest as ring-enhancing of nodular lesions on magnetic resonance imaging (MRI). These imaging findings are also observed in other lesions like metastases and toxoplasmosis. Purpose: To study the MRI perfusion characteristics of tuberculomas and its potential role in their definitive diagnosis. Material and Methods: Thirty-four tuberculomas were evaluated by conventional and perfusion MRI. The relative cerebral blood volume (rCBV) values of the center, peripheral wall, and perilesional neuroparenchymal tissue were calculated using rCBV maps. Ten ring-enhancing metastases were similarly evaluated and rCBV values of their peripheral walls were calculated. Results: Thirty-one of the 34 tuberculomas were ring-enhancing or conglomerate lesions and revealed hypoperfused centers with hyperperfused peripheral walls, with the mean rCBV ± SD being 0.42 ± 0.25 and 2.04 ± 0.61, respectively. Three nodular enhancing lesions showed predominantly homogenous hyperperfusion, with the mean rCBV measuring 2.96 ± 0.39 (mean ± SD). The perilesional neuroparenchyma was hypoperfused in both cases. The metastases revealed mean rCBV ratio of the peripheral wall to be 5.43 ± 2.1 (mean ± SD). Analysis of the values by ROC curve method revealed a cut-off value of ≥3.745 for differentiating ring-enhancing metastases from ring-enhancing tuberculomas. Conclusion: Perfusion MR is a useful tool for the assessment of tuberculomas and can help differentiate them from neoplasms like metastases. It also has a potential role in monitoring therapy and for early detection of drug resistance

Metabolic and hemodynamic evaluation of brain metastases from small cell lung cancer with positron emission tomography

DEFF Research Database (Denmark)

Lassen, U; Andersen, P; Daugaard, G

1998-01-01

for studies of metabolic and hemodynamic features. This study was performed to determine regional cerebral metabolic rate of glucose (rCMRglu), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) in brain metastases from small cell lung cancer and the surrounding brain. Tumor r......Brain metastases from small cell lung cancer respond to chemotherapy, but response duration is short and the intracerebral concentration of chemotherapy may be too low because of the characteristics of the blood-brain barrier. Positron emission tomography has been applied in a variety of tumors...

Tranexamic Acid Reduced the Percent of Total Blood Volume Lost During Adolescent Idiopathic Scoliosis Surgery.

Science.gov (United States)

Jones, Kristen E; Butler, Elissa K; Barrack, Tara; Ledonio, Charles T; Forte, Mary L; Cohn, Claudia S; Polly, David W

2017-01-01

Multilevel posterior spine fusion is associated with significant intraoperative blood loss. Tranexamic acid is an antifibrinolytic agent that reduces intraoperative blood loss. The goal of this study was to compare the percent of total blood volume lost during posterior spinal fusion (PSF) with or without tranexamic acid in patients with adolescent idiopathic scoliosis (AIS). Thirty-six AIS patients underwent PSF in 2011-2014; the last half (n=18) received intraoperative tranexamic acid. We retrieved relevant demographic, hematologic, intraoperative and outcomes information from medical records. The primary outcome was the percent of total blood volume lost, calculated from estimates of intraoperative blood loss (numerator) and estimated total blood volume per patient (denominator, via Nadler's equations). Unadjusted outcomes were compared using standard statistical tests. Tranexamic acid and no-tranexamic acid groups were similar (all p>0.05) in mean age (16.1 vs. 15.2 years), sex (89% vs. 83% female), body mass index (22.2 vs. 20.2 kg/m2), preoperative hemoglobin (13.9 vs. 13.9 g/dl), mean spinal levels fused (10.5 vs. 9.6), osteotomies (1.6 vs. 0.9) and operative duration (6.1 hours, both). The percent of total blood volume lost (TBVL) was significantly lower in the tranexamic acid-treated vs. no-tranexamic acid group (median 8.23% vs. 14.30%, p = 0.032); percent TBVL per level fused was significantly lower with tranexamic acid than without it (1.1% vs. 1.8%, p=0.048). Estimated blood loss (milliliters) was similar across groups. Tranexamic acid significantly reduced the percentage of total blood volume lost versus no tranexamic acid in AIS patients who underwent PSF using a standardized blood loss measure.Level of Evidence: 3. Institutional Review Board status: This medical record chart review (minimal risk) study was approved by the University of Minnesota Institutional Review Board.

Non-equilibrium Inertial Separation Array for High-throughput, Large-volume Blood Fractionation.

Science.gov (United States)

Mutlu, Baris R; Smith, Kyle C; Edd, Jon F; Nadar, Priyanka; Dlamini, Mcolisi; Kapur, Ravi; Toner, Mehmet

2017-08-30

Microfluidic blood processing is used in a range of applications from cancer therapeutics to infectious disease diagnostics. As these applications are being translated to clinical use, processing larger volumes of blood in shorter timescales with high-reliability and robustness is becoming a pressing need. In this work, we report a scaled, label-free cell separation mechanism called non-equilibrium inertial separation array (NISA). The NISA mechanism consists of an array of islands that exert a passive inertial lift force on proximate cells, thus enabling gentler manipulation of the cells without the need of physical contact. As the cells follow their size-based, deterministic path to their equilibrium positions, a preset fraction of the flow is siphoned to separate the smaller cells from the main flow. The NISA device was used to fractionate 400 mL of whole blood in less than 3 hours, and produce an ultrapure buffy coat (96.6% white blood cell yield, 0.0059% red blood cell carryover) by processing whole blood at 3 mL/min, or ∼300 million cells/second. This device presents a feasible alternative for fractionating blood for transfusion, cellular therapy and blood-based diagnostics, and could significantly improve the sensitivity of rare cell isolation devices by increasing the processed whole blood volume.

3H-dextran method for measurements of the blood volume in the rat choroid

International Nuclear Information System (INIS)

Matsusaka, Toshihiko; Morimoto, Kazuhiro; Kikkawa, Yoshizo.

1980-01-01

A new method was developed using 3 H-dextran for measuring the blood volume in the choroid. Under pentobarbital-anesthesia, albino rats weighing 200 grams were perfused through the left ventricle with a 2.5 percent glutaraldehyde solution containing the radioactive dextran. The procedure allowed exchange of the choroidal blood with the 3 H-dextran solution with a simultaneous fixation of the choroid. The blood volume in the choroid was calculated from the radioactivity count, which is estimated to be 1.690 x 10 -4 ml per mg wet weight and 5.070 x 10 -4 ml per mg dry weight. Epinephrine subconjunctivally injected diminished the blood volume in the choroid by 68 percent. Pretreatment with lidocaine almost nullified the effect of epinephrine. Applicability of this method to the analytical study of the choroidal circulation is discussed. (author)

Blood, blood compounds and cell cultures irradiation in clinical radiotherapy equipment: studies on ideal volume and dose

International Nuclear Information System (INIS)

Fernandes, Marco Antonio R.; Pereira, Adelino Jose; Novaes, Paulo Eduardo R.S.

1995-01-01

The authors present the technic and equipment used by the Physical Radiologic Service of Radiation Therapy Department of A.C. Camargo Hospital to irradiate blood and blood compounds. The practical routine is illustrated. The results from others Institutions are presented, discussing about the homogeneity of dose of 2000 to 3500 c Gy to all target volume, sufficient to neutralize cells responsible by graft-versus-host disease from blood transfusions. (author). 6 refs., 2 figs., 1 tab

Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke

International Nuclear Information System (INIS)

Koome, Miriam; Thevathasan, Arthur; Yan, Bernard; Churilov, Leonid; Chen, Ziyuan; Chen, Ziyi; Naylor, Jillian; Kwan, Patrick

2016-01-01

Cerebral cortical ischemia is a risk factor for post-stroke seizures. However, the optimal imaging method is unclear. We investigated CT perfusion (CTP) in detecting cortical ischemia and its correlation with post-stroke seizures compared with non-contrast CT (NCCT). We included patients with acute ischemic stroke admitted to the Royal Melbourne Hospital between 2009 and 2014. Post-stroke seizure information was collected. Cortical involvement was determined on acute NCCT and CTP (T max , cerebral blood volume [CBV], and cerebral blood flow [CBF]). The association between cortical involvement detected by different imaging modalities and post-stroke seizures was examined. Three-hundred fifty-two patients were included for analysis. Fifty-nine percent were male, and median age was 73 years (inter-quartile range 61-82). Follow-up was available for 96 %; median follow-up duration was 377 days (inter-quartile range 91-1018 days). Thirteen patients had post-stroke seizures (3.9 %). Cortical involvement was significantly associated with post-stroke seizures across all modalities. CBV had the highest hazard ratio (11.3, 95 % confidence interval (CI) 1.1-41.2), followed by NCCT (5.3, 95 % CI 1.5-18.0) and CBF (4.2, 95 % CI 1.1-15.2). Sensitivity was highest for T max (100 %), followed by CBV and CBF (both 76.9 %) and NCCT (63.6 %). Specificity was highest for CBV (77.8 %), then NCCT (75.6 %), CBF (54.0 %), and T max (29.1 %). Receiver-operating characteristic area under the curve was significantly different between imaging modalities (p < 0.001), CBV 0.77, NCCT 0.70, CBF 0.65, and T max 0.65. CTP may improve sensitivity and specificity of cortical involvement for post-stroke seizures compared to NCCT. (orig.)

Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke

Energy Technology Data Exchange (ETDEWEB)

Koome, Miriam; Thevathasan, Arthur; Yan, Bernard [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); Churilov, Leonid [University of Melbourne, Florey Neuroscience Institutes, Austin Health, Melbourne (Australia); Chen, Ziyuan [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); Tsinghua University, School of Medicine, Beijing (China); Chen, Ziyi [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); Sun Yat-Sen University, First Affiliated Hospital, Guangdong (China); Naylor, Jillian; Kwan, Patrick [The Royal Melbourne Hospital, Melbourne Brain Centre, Parkville, VIC (Australia); The University of Melbourne, Department of Medicine, Melbourne (Australia)

2016-06-15

Cerebral cortical ischemia is a risk factor for post-stroke seizures. However, the optimal imaging method is unclear. We investigated CT perfusion (CTP) in detecting cortical ischemia and its correlation with post-stroke seizures compared with non-contrast CT (NCCT). We included patients with acute ischemic stroke admitted to the Royal Melbourne Hospital between 2009 and 2014. Post-stroke seizure information was collected. Cortical involvement was determined on acute NCCT and CTP (T{sub max}, cerebral blood volume [CBV], and cerebral blood flow [CBF]). The association between cortical involvement detected by different imaging modalities and post-stroke seizures was examined. Three-hundred fifty-two patients were included for analysis. Fifty-nine percent were male, and median age was 73 years (inter-quartile range 61-82). Follow-up was available for 96 %; median follow-up duration was 377 days (inter-quartile range 91-1018 days). Thirteen patients had post-stroke seizures (3.9 %). Cortical involvement was significantly associated with post-stroke seizures across all modalities. CBV had the highest hazard ratio (11.3, 95 % confidence interval (CI) 1.1-41.2), followed by NCCT (5.3, 95 % CI 1.5-18.0) and CBF (4.2, 95 % CI 1.1-15.2). Sensitivity was highest for T{sub max} (100 %), followed by CBV and CBF (both 76.9 %) and NCCT (63.6 %). Specificity was highest for CBV (77.8 %), then NCCT (75.6 %), CBF (54.0 %), and T{sub max} (29.1 %). Receiver-operating characteristic area under the curve was significantly different between imaging modalities (p < 0.001), CBV 0.77, NCCT 0.70, CBF 0.65, and T{sub max} 0.65. CTP may improve sensitivity and specificity of cortical involvement for post-stroke seizures compared to NCCT. (orig.)

Hyperperfusion on Perfusion Computed Tomography Following Revascularization for Acute Stroke

International Nuclear Information System (INIS)

Nguyen, T.B.; Lum, C.; Eastwood, J.D.; Stys, P.K.; Hogan, M.; Goyal, M.

2005-01-01

Purpose: To describe the findings of hyperperfusion on perfusion computed tomography (CT) in four patients following revascularization for acute stroke. Material and Methods: In 2002-2003, among a series of 6 patients presenting with an acute stroke and treated with intra-arterial thrombolysis, we observed the presence of hyperperfusion in 3 patients on the follow-up CT perfusion. We included an additional patient who was treated with intravenous thrombolysis and who had hyperperfusion on the follow-up CT perfusion. We retrospectively analyzed their CT perfusion maps. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps were compared between the affected territory and the normal contralateral hemisphere. Results: In the four patients, the mean CBV and CBF were 3.6±2.0 ml/100 g and 39±25 ml/100 g/min in the affected territory compared to the normal side (mean CBV 2.7±2.1 ml/100 g, mean CBF = 27±23 ml/100 g/min). There was no intracranial hemorrhage in the hyperperfused territories. At follow-up CT, some hyperperfused brain areas progressed to infarction, while others retained normal white to gray matter differentiation. Conclusion: CT perfusion can demonstrate hyperperfusion, which can be seen in an ischemic brain territory following recanalization

Doppler sonography of diabetic feet: Quantitative analysis of blood flow volume

International Nuclear Information System (INIS)

Seo, Young Lan; Kim, Ho Chul; Choi, Chul Soon; Yoon, Dae Young; Han, Dae Hee; Moon, Jeung Hee; Bae, Sang Hoon

2002-01-01

To analyze Doppler sonographic findings of diabetic feet by estimating the quantitative blood flow volume and by analyzing waveform on Doppler. Doppler sonography was performed in thirty four patients (10 diabetic patients with foot ulceration, 14 diabetic patients without ulceration and 10 normal patients as the normal control group) to measure the flow volume of the arteries of the lower extremities (posterior and anterior tibial arteries, and distal femoral artery. Analysis of doppler waveforms was also done to evaluate the nature of the changed blood flow volume of diabetic patients, and the waveforms were classified into triphasic, biphasic-1, biphasic-2 and monophasic patterns. Flow volume of arteries in diabetic patients with foot ulceration was increased witha statistical significance when compared to that of diabetes patients without foot ulceration of that of normal control group (P<0.05). Analysis of Doppler waveform revealed that the frequency of biphasic-2 pattern was significantly higher in diabetic patients than in normal control group(p<0.05). Doppler sonography in diabetic feet showed increased flow volume and biphasic Doppler waveform, and these findings suggest neuropathy rather than ischemic changes in diabetic feet.

Doppler sonography of diabetic feet: Quantitative analysis of blood flow volume

Energy Technology Data Exchange (ETDEWEB)

Seo, Young Lan; Kim, Ho Chul; Choi, Chul Soon; Yoon, Dae Young; Han, Dae Hee; Moon, Jeung Hee; Bae, Sang Hoon [Hallym University College of Medicine, Seoul (Korea, Republic of)

2002-09-15

To analyze Doppler sonographic findings of diabetic feet by estimating the quantitative blood flow volume and by analyzing waveform on Doppler. Doppler sonography was performed in thirty four patients (10 diabetic patients with foot ulceration, 14 diabetic patients without ulceration and 10 normal patients as the normal control group) to measure the flow volume of the arteries of the lower extremities (posterior and anterior tibial arteries, and distal femoral artery. Analysis of doppler waveforms was also done to evaluate the nature of the changed blood flow volume of diabetic patients, and the waveforms were classified into triphasic, biphasic-1, biphasic-2 and monophasic patterns. Flow volume of arteries in diabetic patients with foot ulceration was increased witha statistical significance when compared to that of diabetes patients without foot ulceration of that of normal control group (P<0.05). Analysis of Doppler waveform revealed that the frequency of biphasic-2 pattern was significantly higher in diabetic patients than in normal control group(p<0.05). Doppler sonography in diabetic feet showed increased flow volume and biphasic Doppler waveform, and these findings suggest neuropathy rather than ischemic changes in diabetic feet.

Chronic fatigue syndrome: illness severity, sedentary lifestyle, blood volume and evidence of diminished cardiac function.

Science.gov (United States)

Hurwitz, Barry E; Coryell, Virginia T; Parker, Meela; Martin, Pedro; Laperriere, Arthur; Klimas, Nancy G; Sfakianakis, George N; Bilsker, Martin S

2009-10-19

The study examined whether deficits in cardiac output and blood volume in a CFS (chronic fatigue syndrome) cohort were present and linked to illness severity and sedentary lifestyle. Follow-up analyses assessed whether differences in cardiac output levels between CFS and control groups were corrected by controlling for cardiac contractility and TBV (total blood volume). The 146 participants were subdivided into two CFS groups based on symptom severity data, severe (n=30) and non-severe (n=26), and two healthy non-CFS control groups based on physical activity, sedentary (n=58) and non-sedentary (n=32). Controls were matched to CFS participants using age, gender, ethnicity and body mass. Echocardiographic measures indicated that the severe CFS participants had 10.2% lower cardiac volume (i.e. stroke index and end-diastolic volume) and 25.1% lower contractility (velocity of circumferential shortening corrected by heart rate) than the control groups. Dual tag blood volume assessments indicated that the CFS groups had lower TBV, PV (plasma volume) and RBCV (red blood cell volume) than control groups. Of the CFS subjects with a TBV deficit (i.e. > or = 8% below ideal levels), the mean+/-S.D. percentage deficit in TBV, PV and RBCV were -15.4+/-4.0, -13.2+/-5.0 and -19.1+/-6.3% respectively. Lower cardiac volume levels in CFS were substantially corrected by controlling for prevailing TBV deficits, but were not affected by controlling for cardiac contractility levels. Analyses indicated that the TBV deficit explained 91-94% of the group differences in cardiac volume indices. Group differences in cardiac structure were offsetting and, hence, no differences emerged for left ventricular mass index. Therefore the findings indicate that lower cardiac volume levels, displayed primarily by subjects with severe CFS, were not linked to diminished cardiac contractility levels, but were probably a consequence of a co-morbid hypovolaemic condition. Further study is needed to address

Early CT perfusion mismatch in acute stroke is not time-dependent but relies on collateralization grade

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Baumgarten, Louisa von; Straube, Andreas [University of Munich Hospitals, Department of Neurology, Munich (Germany); Thierfelder, Kolja M.; Beyer, Sebastian E.; Baumann, Alena B.; Bollwein, Christine; Reiser, Maximilian F.; Sommer, Wieland H. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Janssen, Hendrik [Ludwig-Maximilians-University Hospital Munich, Department of Neuroradiology, Munich (Germany)

2016-04-15

Factors that determine the extent of the penumbra in the initial diagnostic workup using whole brain CT Perfusion (WB-CTP) remain unclear. The purpose of the current study was to determine a possible dependency of the initial mismatch size between cerebral blood flow (CBF) and cerebral blood volume (CBV) from time after symptom onset, leptomeningeal collateralization, and occlusion localization in acute middle cerebral artery (MCA) infarctions. Out of an existing cohort of 992 consecutive patients receiving multiparametric CT scans including WB-CTP due to suspected stroke, we included patients who had (1) a witnessed time of symptom onset, (2) an infarction of the MCA territory as documented by follow-up imaging, and (3) an initial CBF volume of >10 ml. CBF and CBV lesion sizes, collateralization grade, and the site of occlusion were determined. We included 103 patients. Univariate analysis showed that time from symptom onset (168 +/- 91.2 min) did not correlate with relative or absolute mismatch volumes (p = 0.458 and p = 0.921). Higher collateralization gradings were associated with small absolute mismatch volumes (p = 0.004 and p < 0.001). Internal carotid artery (ICA) occlusions were associated with large absolute mismatch volumes (p = 0.004). Multivariate analysis confirmed that ICA occlusion was associated with large absolute mismatch volumes (p = 0.005), and high collateral grade was associated with small absolute mismatch volumes (p = 0.017). There is no significant correlation between initial CTP mismatch and time after symptom onset. Predictors of mismatch size include the extent of the collaterals and a proximal location of the occlusion. (orig.)

Apparent brain temperature imaging with multi-voxel proton magnetic resonance spectroscopy compared with cerebral blood flow and metabolism imaging on positron emission tomography in patients with unilateral chronic major cerebral artery steno-occlusive disease

Energy Technology Data Exchange (ETDEWEB)

Nanba, Takamasa; Nishimoto, Hideaki; Murakami, Toshiyuki; Fujiwara, Shunrou; Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Iwate (Japan); Yoshioka, Yoshichika [Osaka University, Open and Transdisciplinary Research Initiatives, Osaka (Japan); Sasaki, Makoto; Uwano, Ikuko [Iwate Medical University, Institute for Biomedical Science, Iwate (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Iwate (Japan)

2017-09-15

The purpose of the present study was to determine whether apparent brain temperature imaging using multi-voxel proton magnetic resonance (MR) spectroscopy correlates with cerebral blood flow (CBF) and metabolism imaging in the deep white matter of patients with unilateral chronic major cerebral artery steno-occlusive disease. Apparent brain temperature and CBF and metabolism imaging were measured using proton MR spectroscopy and {sup 15}O-positron emission tomography (PET), respectively, in 35 patients. A set of regions of interest (ROIs) of 5 x 5 voxels was placed on an MR image so that the voxel row at each edge was located in the deep white matter of the centrum semiovale in each cerebral hemisphere. PET images were co-registered with MR images with these ROIs and were re-sliced automatically using image analysis software. In 175 voxel pairs located in the deep white matter, the brain temperature difference (affected hemisphere - contralateral hemisphere: ΔBT) was correlated with cerebral blood volume (CBV) (r = 0.570) and oxygen extraction fraction (OEF) ratios (affected hemisphere/contralateral hemisphere) (r = 0.641). We excluded voxels that contained ischemic lesions or cerebrospinal fluid and calculated the mean values of voxel pairs in each patient. The mean ΔBT was correlated with the mean CBF (r = - 0.376), mean CBV (r = 0.702), and mean OEF ratio (r = 0.774). Apparent brain temperature imaging using multi-voxel proton MR spectroscopy was correlated with CBF and metabolism imaging in the deep white matter of patients with unilateral major cerebral artery steno-occlusive disease. (orig.)

Prediction of Packed Cell Volume after Whole Blood Transfusion in Small Ruminants and South American Camelids: 80 Cases (2006-2016).

Science.gov (United States)

Luethy, D; Stefanovski, D; Salber, R; Sweeney, R W

2017-11-01

Calculation of desired whole blood transfusion volume relies on an estimate of an animal's circulating blood volume, generally accepted to be 0.08 L/kg or 8% of the animal's body weight in kilograms. To use packed cell volume before and after whole blood transfusion to evaluate the accuracy of a commonly used equation to predict packed cell volume after transfusion in small ruminants and South American camelids; to determine the nature and frequency of adverse transfusion reactions in small ruminants and camelids after whole blood transfusion. Fifty-eight small ruminants and 22 alpacas that received whole blood transfusions for anemia. Retrospective case series; medical record review for small ruminants and camelids that received whole blood transfusions during hospitalization. Mean volume of distribution of blood as a fraction of body weight in sheep (0.075 L/kg, 7.5% BW) and goats (0.076 L/kg, 7.6% BW) differed significantly (P blood volume (volume of distribution of blood) is adequate for calculation of transfusion volumes; however, use of the species-specific circulating blood volume can improve calculation of transfusion volume to predict and achieve desired packed cell volume. The incidence of transfusion reactions in small ruminants and camelids is low. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Orthostatic changes in the blood volumes of the lower extremities in practically healthy humans

Energy Technology Data Exchange (ETDEWEB)

Frolov, V K; Koshkin, V M; Karalkin, A V [Vtoroj Moskovskij Gosudarstvennyj Meditsinskij Inst. (USSR)

1979-07-01

The method and the results of measuring the blood volumes in the lower extremities in the horizontal and vertical position of the body are given. A combination of a single-sensor counter of the whole body and a gamma-chamber with the use of two nondiffuse active radioindicators, erythrocytes labelled with /sup 51/Cr and albumin-sup(99m)Tc in certain sequence, is found to be the most optimal for quantitative evaluation of the regional volumes of the blood. To raise the informativeness of the studies the authors recommend distinguishing ''rapid'' and ''slow'' fractions of the blood volume progressive growth in the crus since the correlation of these fractions reflect the specific features of an individual orthostatic reaction for each examinee.

Computed Tomography Perfusion Alberta Stroke Program Early Computed Tomography Score Is Associated with Hemorrhagic Transformation after Acute Cardioembolic Stroke

Directory of Open Access Journals (Sweden)

Lan Liu

2017-11-01

Full Text Available Alberta Stroke Program Early Computed Tomography (CT score (ASPECTS has been applied to CT perfusion (CTP with good interrater agreement to predict early ischemic stroke, and it can be useful in decision making in acute ischemic stroke. The aim of the present study was to assess the predictive value of CTP ASPECTS of hemorrhagic transformation (HT in acute cardioembolic stroke. This is a single-enter, retrospective study. All patients hospitalized with acute cardioembolic stroke from January 2008 to September 2013 were included. ASPECTS of baseline non-contrast CT, CTP maps of cerebral blood volume (CBV, cerebral blood flow, and mean transit time were collected from 52 consecutive patients with less than 12-h anterior circulation ischemic stroke. MRI scan was performed within 72 h of symptom onset after index stroke including T2*-weighted gradient echo to identify HT. For bleeding risk assessment, CTP and diffusion-weighted imaging ASPECTS were categorized into 0–7 or 8–10. Baseline characteristics, ASPCETS scores and HT were compared. Eighteen (34.6% patients had HT and four (7.7% developed symptomatic HT. On univariate analysis, the proportion of patients with CBV-ASPECTS 0–7 was significantly higher in HT patients as compared to patients without HT (44 versus 9%, P = 0.005. CBV ASPECTS 0–7 remained independent prognostic factors for HT after adjustment for clinical baseline variables. CBV ASPECTS could be of value to predict HT risk after acute cardioembolic stroke and may be a quick risk assessment approach before reperfusion therapy.

Paradoxical perfusion metrics of high-grade gliomas with an oligodendroglioma component: quantitative analysis of dynamic susceptibility contrast perfusion MR imaging

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Sunwoo, Leonard; Park, Sun-Won [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul Metropolitan Government - Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Choi, Seung Hong [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University, Center for Nanoparticle Research, Institute for Basic Science, and School of Chemical and Biological Engineering, Seoul (Korea, Republic of); Yoo, Roh-Eul; Kang, Koung Mi; Yun, Tae Jin; Kim, Ji-hoon; Sohn, Chul-Ho [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Kim, Tae Min; Lee, Se-Hoon [Seoul National University Hospital, Department of Internal Medicine, Seoul (Korea, Republic of); Park, Chul-Kee [Seoul National University Hospital, Department of Neurosurgery, Seoul (Korea, Republic of); Won, Jae-Kyung; Park, Sung-Hye [Seoul National University Hospital, Department of Pathology, Seoul (Korea, Republic of); Kim, Il Han [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of)

2015-11-15

The aim of this study is to investigate perfusion characteristics of glioblastoma with an oligodendroglioma component (GBMO) compared with conventional glioblastoma (GBM) using dynamic susceptibility contrast (DSC) perfusion magnetic resonance (MR) imaging and microvessel density (MVD). The study was approved by the institutional review board. Newly diagnosed high-grade glioma patients were enrolled (n = 72; 20 GBMs, 14 GBMOs, 19 anaplastic astrocytomas (AAs), 13 anaplastic oligodendrogliomas (AOs), and six anaplastic oligoastrocytomas (AOAs)). All participants underwent preoperative MR imaging including DSC perfusion MR imaging. Normalized cerebral blood volume (nCBV) values were analyzed using a histogram approach. Histogram parameters were subsequently compared across each tumor subtype and grade. MVD was quantified by immunohistochemistry staining and correlated with perfusion parameters. Progression-free survival (PFS) was assessed according to the tumor subtype. GBMO displayed significantly reduced nCBV values compared with GBM, whereas grade III tumors with oligodendroglial components (AO and AOA) exhibited significantly increased nCBV values compared with AA (p < 0.001). MVD analyses revealed the same pattern as nCBV results. In addition, a positive correlation between MVD and nCBV values was noted (r = 0.633, p < 0.001). Patients with oligodendroglial tumors exhibited significantly increased PFS compared with patients with pure astrocytomas in each grade. In contrast to grade III tumors, the presence of oligodendroglial components in grade IV tumors resulted in paradoxically reduced perfusion metrics and MVD. In addition, patients with GBMO exhibited a better clinical outcome compared with patients with GBM. (orig.)

Fluorescence Exclusion: A Simple Method to Assess Projected Surface, Volume and Morphology of Red Blood Cells Stored in Blood Bank

Directory of Open Access Journals (Sweden)

Camille Roussel

2018-05-01

Full Text Available Red blood cells (RBC ability to circulate is closely related to their surface area-to-volume ratio. A decrease in this ratio induces a decrease in RBC deformability that can lead to their retention and elimination in the spleen. We recently showed that a subpopulation of “small RBC” with reduced projected surface area accumulated upon storage in blood bank concentrates, but data on the volume of these altered RBC are lacking. So far, single cell measurement of RBC volume has remained a challenging task achieved by a few sophisticated methods some being subject to potential artifacts. We aimed to develop a reproducible and ergonomic method to assess simultaneously RBC volume and morphology at the single cell level. We adapted the fluorescence exclusion measurement of volume in nucleated cells to the measurement of RBC volume. This method requires no pre-treatment of the cell and can be performed in physiological or experimental buffer. In addition to RBC volume assessment, brightfield images enabling a precise definition of the morphology and the measurement of projected surface area can be generated simultaneously. We first verified that fluorescence exclusion is precise, reproducible and can quantify volume modifications following morphological changes induced by heating or incubation in non-physiological medium. We then used the method to characterize RBC stored for 42 days in SAG-M in blood bank conditions. Simultaneous determination of the volume, projected surface area and morphology allowed to evaluate the surface area-to-volume ratio of individual RBC upon storage. We observed a similar surface area-to-volume ratio in discocytes (D and echinocytes I (EI, which decreased in EII (7% and EIII (24%, sphero-echinocytes (SE; 41% and spherocytes (S; 47%. If RBC dimensions determine indeed the ability of RBC to cross the spleen, these modifications are expected to induce the rapid splenic entrapment of the most morphologically altered RBC

Noninvasive measurement of cardiopulmonary blood volume: evaluation of the centroid method

International Nuclear Information System (INIS)

Fouad, F.M.; MacIntyre, W.J.; Tarazi, R.C.

1981-01-01

Cardiopulmonary blood volume (CPV) and mean pulmonary transit time (MTT) determined by radionuclide measurements (Tc-99m HSA) were compared with values obtained from simultaneous dye-dilution (DD) studies (indocyanine green). The mean transit time was obtained from radionuclide curves by two methods: the peak-to-peak time and the interval between the two centroids determined from the right and left-ventricular time-concentration curves. Correlation of dye-dilution MTT and peak-to-peak time was significant (r = 0.79, p < 0.001), but its correlation with centroid-derived values was better (r = 0.86, p < 0.001). CPV values (using the centroid method for radionuclide technique) correlated significantly with values derived from dye-dilution curves (r = 0.74, p < 0.001). Discrepancies between the two were greater the more rapid the circulation (r = 0.61, p < 0.01), suggesting that minor inaccuracies of dye-dilution methods, due to positioning or delay of the system, can become magnified in hyperkinetic conditions. The radionuclide method is simple, repeatable, and noninvasive, and it provides simultaneous evaluation of pulmonary and systemic hemodynamics. Further, calculation of the ratio of cardiopulmonary to total blood volume can be used as an index of overall venous distensibility and relocation of intravascular blood volume

/sup 3/H-dextran method for measurements of the blood volume in the rat choroid

Energy Technology Data Exchange (ETDEWEB)

Matsusaka, T [Osaka Prefectural Center for Adult Diseases (Japan); Morimoto, K; Kikkawa, Y

1980-01-01

A new method was developed using /sup 3/H-dextran for measuring the blood volume in the choroid. Under pentobarbital-anesthesia, albino rats weighing 200 grams were perfused through the left ventricle with a 2.5 percent glutaraldehyde solution containing the radioactive dextran. The procedure allowed exchange of the choroidal blood with the /sup 3/H-dextran solution with a simultaneous fixation of the choroid. The blood volume in the choroid was calculated from the radioactivity count, which is estimated to be 1.690 x 10/sup -4/ ml per mg wet weight and 5.070 x 10/sup -4/ ml per mg dry weight. Epinephrine subconjunctivally injected diminished the blood volume in the choroid by 68 percent. Pretreatment with lidocaine almost nullified the effect of epinephrine. Applicability of this method to the analytical study of the choroidal circulation is discussed.

Determination of the blood volume on young trotters with J131-HSA (RIHSA)

International Nuclear Information System (INIS)

Adamopoulou, B.

1975-01-01

We have examined the accuracy of our method of determining blood volume and its utility under field conditions on forty trotters of the same age. Furthermore we were interested in to what extent it is possible to conclude from the quantity of blood emitted by the corresponding blood reservoirs on the capacity of sport horses. The blood volume determination was carried out with J 131 -human-serum-albumin, after we had excluded the usability of Cr 51 by reason of radiological protection. Our results show that the methodical total error, which we had determined from four different controls is so low under field conditions that our method can be used in the field with highly evaltable results. The percentage of blood emitted by the reservoirs gives information only about the momentary capacity of a horse. It is not an objective measure for the future capacity of a growing horse for this is influenced by too many endogenic an exogenic factors. (orig.) [de

Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas.

Science.gov (United States)

Bell, L C; Does, M D; Stokes, A M; Baxter, L C; Schmainda, K M; Dueck, A C; Quarles, C C

2017-09-01

The optimal TE must be calculated to minimize the variance in CBV measurements made with DSC MR imaging. Simulations can be used to determine the influence of the TE on CBV, but they may not adequately recapitulate the in vivo heterogeneity of precontrast T2*, contrast agent kinetics, and the biophysical basis of contrast agent-induced T2* changes. The purpose of this study was to combine quantitative multiecho DSC MRI T2* time curves with error analysis in order to compute the optimal TE for a traditional single-echo acquisition. Eleven subjects with high-grade gliomas were scanned at 3T with a dual-echo DSC MR imaging sequence to quantify contrast agent-induced T2* changes in this retrospective study. Optimized TEs were calculated with propagation of error analysis for high-grade glial tumors, normal-appearing white matter, and arterial input function estimation. The optimal TE is a weighted average of the T2* values that occur as a contrast agent bolus transverses a voxel. The mean optimal TEs were 30.0 ± 7.4 ms for high-grade glial tumors, 36.3 ± 4.6 ms for normal-appearing white matter, and 11.8 ± 1.4 ms for arterial input function estimation (repeated-measures ANOVA, P optimal TE values for high-grade gliomas, and mean values of all 3 ROIs were statistically significant. The optimal TE for the arterial input function estimation is much shorter; this finding implies that quantitative DSC MR imaging acquisitions would benefit from multiecho acquisitions. In the case of a single-echo acquisition, the optimal TE prescribed should be 30-35 ms (without a preload) and 20-30 ms (with a standard full-dose preload). © 2017 by American Journal of Neuroradiology.

Muscle blood volume assessment during exercise with Power Doppler Ultrasound

NARCIS (Netherlands)

Heres, H.M.; Tchang, B.C.Y.; Schoots, T.; Rutten, M.C.M.; van de Vosse, F.N.; Lopata, R.G.P.

2016-01-01

Assessment of perfusion adaptation in muscle during exercise can provide diagnostic information on cardiac and endothelial diseases. Power Doppler Ultrasound (PDUS) is known for its feasibility in the non-invasive measurement of moving blood volume (MBV), a perfusion related parameter. In this

Understanding the heterogeneity in volume overload and fluid distribution in decompensated heart failure is key to optimal volume management: role for blood volume quantitation.

Science.gov (United States)

Miller, Wayne L; Mullan, Brian P

2014-06-01

This study sought to quantitate total blood volume (TBV) in patients hospitalized for decompensated chronic heart failure (DCHF) and to determine the extent of volume overload, and the magnitude and distribution of blood volume and body water changes following diuretic therapy. The accurate assessment and management of volume overload in patients with DCHF remains problematic. TBV was measured by a radiolabeled-albumin dilution technique with intravascular volume, pre-to-post-diuretic therapy, evaluated at hospital admission and at discharge. Change in body weight in relation to quantitated TBV was used to determine interstitial volume contribution to total fluid loss. Twenty-six patients were prospectively evaluated. Two patients had normal TBV at admission. Twenty-four patients were hypervolemic with TBV (7.4 ± 1.6 liters) increased by +39 ± 22% (range, +9.5% to +107%) above the expected normal volume. With diuresis, TBV decreased marginally (+30 ± 16%). Body weight declined by 6.9 ± 5.2 kg, and fluid intake/fluid output was a net negative 8.4 ± 5.2 liters. Interstitial compartment fluid loss was calculated at 6.2 ± 4.0 liters, accounting for 85 ± 15% of the total fluid reduction. TBV analysis demonstrated a wide range in the extent of intravascular overload. Dismissal measurements revealed marginally reduced intravascular volume post-diuretic therapy despite large reductions in body weight. Mobilization of interstitial fluid to the intravascular compartment with diuresis accounted for this disparity. Intravascular volume, however, remained increased at dismissal. The extent, composition, and distribution of volume overload are highly variable in DCHF, and this variability needs to be taken into account in the approach to individualized therapy. TBV quantitation, particularly serial measurements, can facilitate informed volume management with respect to a goal of treating to euvolemia. Copyright © 2014 American College of Cardiology Foundation. Published

Measurement of hepatic volume and effective blood flow with radioactive colloids: Evaluation of development in liver diseases

International Nuclear Information System (INIS)

Fujii, M.; Uchino, H.; Kyoto Univ.

1982-01-01

Changes in hepatic volume and the blood flow effectively perfusing the liver parenchyma were studied as an assessment of the severity of liver diseases. Hepatic effective blood flow was estimated as the hepatic fractional clearance of radioactive colloids, obtained from the disappearance rate multiplied by the fraction of injected dose taken up by the liver. The hepatic fractional clearance was normal or not markedly decreased in patients with acute hepatitis which had developed favorably, but was severely decreased in patients with fulminant hepatitis. In liver diseases, the ratio of hepatic volume to fractional clearance was found to increase as the clearance decreased. In subjects with normal clearance, hepatic fractional clearance was correlated significantly with liver volume, indicating that hepatic effective blood flow is proportional to parenchymal volume in an unanesthetized, resting state. In biopsied cases changes in volume and blood flow accorded well with changes indicated by morphological criteria. In chronic persistent hepatitis, effective hepatic blood flow is not diminished. However, hepatic blood flow were observed between the cirrhosis or chronic aggressive hepatitis, and normal control groups. Extension of chronic inflammatory infiltration into the parenchyma distinguishes chronic aggressive hepatitis from chronic persistent hepatitis. Architecture is often disturbed in the former. These changes should be accompanied by disturbance of microcirculation. The present study indicates that the decrease in effective hepatic blood flow in chronic hepatitis and cirrhosis has two aspects: one is a summation of microcirculatory disturbances, and the other is a decrease in liver cell mass. (orig.)

Cerebral blood volume reactivity to hypercapnia measured with 11C-labelled carboxyhemoglobin and positron emission tomography. Chapter 8

International Nuclear Information System (INIS)

Kanno, Iwao; Uemera, Kazuo; Murakami, Matsutaro; Shishido, Fumio; Tomura, Noriaki

1988-01-01

The purpose of the present study to examine the regionality of the CBV reactivity to changes in PaCO2 employing 11C-labelled carboxyhemoglobin and positron emission tomography (PET). The study was caried out using sequential scans obtained by PET followinng a single administration by the 11CO inhalation method during which activation of either hypercapnia or hypocapnia was induced in the subject. 7 refs.; 6 figs.; 2 tabs

White cell labeling: 20 ML VS 4 ML of blood volume-case reports

International Nuclear Information System (INIS)

Imam, S.K.

1998-01-01

Full text: Some times, it becomes difficult to draw 20 mL blood from a patient with bad veins. On two occasions, we could collect only about 4 mL of blood, that too with a great deal of struggle, and then we carried out the routine labelling procedure. A labelling efficiency of 98.2% and 95.6% was achieved. The white cell scan was negative in one patient, but positive in the next one. In a third patient, a comparison of labelling efficiency was done between 5 and 20 mLs of blood volumes separately and the results were found to be identical, 98.5% and 98.4%, respectively. As we have achieved the usual pattern of white cell scan with as low as 4-5 mL of blood, it appears that enough number of white cells is present even in the 4-5 mL of blood that is capable of generating a white cell scan and so, it seems rational to reduce the blood volume from 20 mL to 4 or 5 mL. However, further studies are warranted before adopting this modification. The procedure appears to carry the following advantages: ease of blood collection, handling and re-injection and less risk to the patient

A reference frame for blood volume in children and adolescents

Directory of Open Access Journals (Sweden)

Donckerwolcke Raymond

2006-02-01

Full Text Available Abstract Background Our primary purpose was to determine the normal range and variability of blood volume (BV in healthy children, in order to provide reference values during childhood and adolescence. Our secondary aim was to correlate these vascular volumes to body size parameters and pubertal stages, in order to determine the best normalisation parameter. Methods Plasma volume (PV and red cell volume (RCV were measured and F-cell ratio was calculated in 77 children with idiopathic nephrotic syndrome in drug-free remission (mean age, 9.8 ± 4.6 y. BV was calculated as the sum of PV and RCV. Due to the dependence of these values on age, size and sex, all data were normalised for body size parameters. Results BV normalised for lean body mass (LBM did not differ significantly by sex (p Conclusion LBM was the anthropometric index most closely correlated to vascular fluid volumes, independent of age, gender and pubertal stage.

Determining the optimal portal blood volume in a shunt before surgery in extrahepatic portal hypertension

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Yurchuk Vladimir A

2016-04-01

Full Text Available The aim of the study: To determine the necessary shunt diameter and assess the optimal portal blood volume in a shunt in children with extrahepatic portal hypertension before the portosystemic shunt surgery. Changes in the liver hemodynamics were studied in 81 children aged from 4 to 7 years with extrahepatic portal hypertension. We established that it is necessary to calculate the shunt diameter and the blood volume in a shunt in patients with extrahepatic portal hypertension before the portosystemic shunt surgery. It allows us to preserve the hepatic portal blood flow and effectively decrease the pressure in the portal system. Portosystemic shunt surgery in patients with extrahepatic portal hypertension performed in accordance with the individualized shunt volume significantly decreases portal pressure, preserves stable hepatic hemodynamics and prevents gastro-esophageal hemorrhage.

Pulmonary diffusing capacity, capillary blood volume, and cardiac output during sustained microgravity

Science.gov (United States)

Prisk, G. K.; Guy, Harold J. B.; Elliott, Ann R.; Deutschman, Robert A., III; West, John B.

1993-01-01

We measured pulmonary diffusing capacity (DL), diffusing capacity per unit lung volume, pulmonary capillary blood volume (Vc), membrane diffusing capacity (Dm), pulmonary capillary blood flow or cardiac output (Qc), and cardiac stroke volume (SV) in four subjects exposed to nine days of microgravity. DL in microgravity was elevated compared with preflight standing values and was higher than preflight supine because of the elevation of both Vc and Dm. The elevation in Vc was comparable to that measured supine in 1 G, but the increase in Dm was in sharp contrast to the supine value. We postulate that, in 0 G, pulmonary capillary blood is evenly distributed throughout the lung, providing for uniform capillary filling, leading to an increase in the surface area available for diffusion. By contrast, in the supine 1-G state, the capillaries are less evenly filled, and although a similar increase in blood volume is observed, the corresponding increase in surface area does not occur. DL and its subdivisions showed no adaptive changes from the first measurement 24 h after the start of 0 G to eight days later. Similarly, there were no trends in the postflight data, suggesting that the principal mechanism of these changes was gravitational. The increase in Dm suggests that subclinical pulmonary edema did not result from exposure to 0 G. Qc was modestly increased inflight and decreased postflight compared with preflight standing. Compared with preflight standing, SV was increased 46 percent inflight and decreased 14 percent in the 1st week postflight. There were temporal changes in Qc and SV during 0 G, with the highest values recorded at the first measurement, 24 h into the flight. The lowest values of Qc and SV occurred on the day of return.

Evaluation of the effects of insufficient blood volume samples on the performance of blood glucose self-test meters.

Science.gov (United States)

Pfützner, Andreas; Schipper, Christina; Ramljak, Sanja; Flacke, Frank; Sieber, Jochen; Forst, Thomas; Musholt, Petra B

2013-11-01

Accuracy of blood glucose readings is (among other things) dependent on the test strip being completely filled with sufficient sample volume. The devices are supposed to display an error message in case of incomplete filling. This laboratory study was performed to test the performance of 31 commercially available devices in case of incomplete strip filling. Samples with two different glucose levels (60-90 and 300-350 mg/dl) were used to generate three different sample volumes: 0.20 µl (too low volume for any device), 0.32 µl (borderline volume), and 1.20 µl (low but supposedly sufficient volume for all devices). After a point-of-care capillary reference measurement (StatStrip, NovaBiomedical), the meter strip was filled (6x) with the respective volume, and the response of the meters (two devices) was documented (72 determinations/meter type). Correct response was defined as either an error message indicating incomplete filling or a correct reading (±20% compared with reference reading). Only five meters showed 100% correct responses [BGStar and iBGStar (both Sanofi), ACCU-CHEK Compact+ and ACCU-CHEK Mobile (both Roche Diagnostics), OneTouch Verio (LifeScan)]. The majority of the meters (17) had up to 10% incorrect reactions [predominantly incorrect readings with sufficient volume; Precision Xceed and Xtra, FreeStyle Lite, and Freedom Lite (all Abbott); GlucoCard+ and GlucoMen GM (both Menarini); Contour, Contour USB, and Breeze2 (all Bayer); OneTouch Ultra Easy, Ultra 2, and Ultra Smart (all LifeScan); Wellion Dialog and Premium (both MedTrust); FineTouch (Terumo); ACCU-CHEK Aviva (Roche); and GlucoTalk (Axis-Shield)]. Ten percent to 20% incorrect reactions were seen with OneTouch Vita (LifeScan), ACCU-CHEK Aviva Nano (Roche), OmniTest+ (BBraun), and AlphaChek+ (Berger Med). More than 20% incorrect reactions were obtained with Pura (Ypsomed), GlucoCard Meter and GlucoMen LX (both Menarini), Elite (Bayer), and MediTouch (Medisana). In summary, partial and

Effects of Anti-VEGF on Predicted Antibody Biodistribution: Roles of Vascular Volume, Interstitial Volume, and Blood Flow

Science.gov (United States)

Boswell, C. Andrew; Ferl, Gregory Z.; Mundo, Eduardo E.; Bumbaca, Daniela; Schweiger, Michelle G.; Theil, Frank-Peter; Fielder, Paul J.; Khawli, Leslie A.

2011-01-01

Background The identification of clinically meaningful and predictive models of disposition kinetics for cancer therapeutics is an ongoing pursuit in drug development. In particular, the growing interest in preclinical evaluation of anti-angiogenic agents alone or in combination with other drugs requires a complete understanding of the associated physiological consequences. Methodology/Principal Findings Technescan™ PYP™, a clinically utilized radiopharmaceutical, was used to measure tissue vascular volumes in beige nude mice that were naïve or administered a single intravenous bolus dose of a murine anti-vascular endothelial growth factor (anti-VEGF) antibody (10 mg/kg) 24 h prior to assay. Anti-VEGF had no significant effect (p>0.05) on the fractional vascular volumes of any tissues studied; these findings were further supported by single photon emission computed tomographic imaging. In addition, apart from a borderline significant increase (p = 0.048) in mean hepatic blood flow, no significant anti-VEGF-induced differences were observed (p>0.05) in two additional physiological parameters, interstitial fluid volume and the organ blood flow rate, measured using indium-111-pentetate and rubidium-86 chloride, respectively. Areas under the concentration-time curves generated by a physiologically-based pharmacokinetic model changed substantially (>25%) in several tissues when model parameters describing compartmental volumes and blood flow rates were switched from literature to our experimentally derived values. However, negligible changes in predicted tissue exposure were observed when comparing simulations based on parameters measured in naïve versus anti-VEGF-administered mice. Conclusions/Significance These observations may foster an enhanced understanding of anti-VEGF effects in murine tissues and, in particular, may be useful in modeling antibody uptake alone or in combination with anti-VEGF. PMID:21436893

CT perfusion imaging on the disturbance of regional cerebral microcirculation in a pre-infarction period: an experimental study

International Nuclear Information System (INIS)

Gao Peiyi; Liang Chenyang; Lin Yan; Yuan Fang; Hu Ling

2003-01-01

Objective: To investigate the CT perfusion imaging and the pathological features on the disturbance of regional cerebral microcirculation in a pre-infarction period, and to evaluate the relationship between the astrocytes and regional cerebral microcirculation. Methods: Dynamic CT perfusion imaging of the models with regional cerebral hypoperfusion and astrocytic swelling in rats was performed to assess the presence or absence of the disturbance of regional cerebral microcirculation. Then, the histopathologic examination was made for both models, respectively. The ratios of side-to-side were measured at hypoperfusion areas in the models of regional cerebral ischemia. Results: Regional hypoperfusion was revealed by regional cerebral blood flow (rCBF) and mean transit time (MTT) maps in the group of hypoperfusion for 6 hours. Regional cerebral blood volume (rCBV) and time-to-peak (TTP) maps were normal in that group. The ratios of rCBF, rCBV, MTT and TTP were 0.39-0.55, 0.92-1.00, 1.20-1.50 and 1.00-1.00 respectively. Astrocytic swelling pressing the capillary wall was obvious and subtle neuronal reversible degeneration was occasionally found. TTC stain was normal. In the tACPD group of astrocytic swelling, the abnormal hemodynamic regions on rCBF and MTT maps were found. The rCBV maps of 3 rats in the tACPD group showed the area of reduced rCBV. In 2 rats of tACPD group, the areas of delayed TTP were also found. The ratios of rCBF, rCBV, MTT and TTP were 0.25-0.44, 0.70-1.01, 1.20-2.00 and 1.02-1.45 respectively. TTC stain was negative. Electron microscope study revealed remarkable swelling of astrocytes, especially endfoot processes of astrocytes around capillaries. The abnormal hemodynamic region on rCBF and MTT maps matched with abnormal extent on histopathologic examination. The rCBV and TTP maps appeared normal. Conclusion: The astrocytes can react in a way faster than the neurons in the pre-infarction period, viz. astrocytic swelling. The swelling of

Preoperative subtyping of meningiomas by perfusion MR imaging

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hao [University Medical Center Groningen, University of Groningen (Netherlands); Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China); Department of Radiology, University of Groningen (Netherlands); Roediger, Lars A.; Oudkerk, Matthijs [University Medical Center Groningen, University of Groningen (Netherlands); Department of Radiology, University of Groningen (Netherlands); Shen, Tianzhen [Fudan University Huashan Hospital, Department of Radiology, Shanghai (China); Miao, Jingtao [Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China)

2008-10-15

This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Thirty-seven meningiomas with peritumoral edema (15 meningothelial, ten fibrous, four angiomatous, and eight anaplastic) underwent perfusion MR imaging by using a gradient echo echo-planar sequence. The maximal rCBV (compared with contralateral normal white matter) in both tumoral parenchyma and peritumoral edema of each tumor was measured. The mean rCBVs of each two histological subtypes were compared using one-way analysis of variance and least significant difference tests. A p value less than 0.05 indicated a statistically significant difference. The mean rCBV of meningothelial, fibrous, angiomatous, and anaplastic meningiomas in tumoral parenchyma were 6.93{+-}3.75, 5.61{+-}4.03, 11.86{+-}1.93, and 5.89{+-}3.85, respectively, and in the peritumoral edema 0.87{+-}0.62, 1.38{+-}1.44, 0.87{+-}0.30, and 3.28{+-}1.39, respectively. The mean rCBV in tumoral parenchyma of angiomatous meningiomas and in the peritumoral edema of anaplastic meningiomas were statistically different (p<0.05) from the other types of meningiomas. Perfusion MR imaging can provide useful functional information on meningiomas and help in the preoperative diagnosis of some subtypes of meningiomas. (orig.)

Optimal differentiation of high- and low-grade glioma and metastasis: a meta-analysis of perfusion, diffusion, and spectroscopy metrics

Energy Technology Data Exchange (ETDEWEB)

Usinskiene, Jurgita; Venius, Jonas; Rynkeviciene, Ryte; Norkus, Darius; Suziedelis, Kestutis [National Cancer Institute, Radiology Center, Vilnius (Lithuania); Ulyte, Agne [Vilnius University, Faculty of Medicine, Vilnius (Lithuania); Bjoernerud, Atle [Oslo University Hospital, Department of Physics, Oslo (Norway); Oslo University Hospital, The Intervention Centre, Oslo (Norway); Katsaros, Vasileios K. [General Anti-Cancer and Oncological Hospital ' ' St. Savvas' ' , Athens (Greece); Letautiene, Simona; Aleknavicius, Eduardas [National Cancer Institute, Radiology Center, Vilnius (Lithuania); Vilnius University, Faculty of Medicine, Vilnius (Lithuania); Rocka, Saulius [Vilnius University, Faculty of Medicine, Vilnius (Lithuania); Faculty of Medicine Vilnius University, Neuroangiosurgery Center, Vilnius (Lithuania); Usinskas, Andrius [Vilnius Gedimino Technical University, Department of Electronic Systems, Vilnius (Lithuania)

2016-04-15

To perform a meta-analysis of advanced magnetic resonance imaging (MRI) metrics, including relative cerebral blood volume (rCBV), normalized apparent diffusion coefficient (nADC), and spectroscopy ratios choline/creatine (Cho/Cr) and choline/N-acetyl aspartate (Cho/NAA), for the differentiation of high- and low-grade gliomas (HGG, LGG) and metastases (MTS). For systematic review, 83 articles (dated 2000-2013) were selected from the NCBI database. Twenty-four, twenty-two, and eight articles were included respectively for spectroscopy, rCBV, and nADC meta-analysis. In the meta-analysis, we calculated overall means for rCBV, nADC, Cho/Cr (short TE - from 20 to 35 ms, medium - from 135 to 144 ms), and Cho/NAA for the HGG, LGG, and MTS groups. We used random effects model to obtain weighted averages and select thresholds. Overall means (with 95 % CI) for rCBV, nADC, Cho/Cr (short and medium echo time, TE), and Cho/NAA were: for HGG 5.47 (4.78-6.15), 1.38 (1.16-1.60), 2.40 (1.67-3.13), 3.27 (2.78-3.77), and 4.71 (3.24-6.19); for LGG 2.00 (1.71-2.28), 1.61 (1.36-1.87), 1.46 (1.20-1.72), 1.71 (1.49-1.93), and 2.36 (1.50-3.23); for MTS 5.06 (3.85-6.27), 1.35 (1.06-1.64), 1.89 (1.72-2.06), 3.14 (1.57-4.72), (Cho/NAA was not available). LGG had significantly lower rCBV, Cho/Cr, and Cho/NAA values than HGG or MTS. No significant differences were found for nADC. Best differentiation between HGG and LGG is obtained from rCBV, Cho/Cr, and Cho/NAA metrics. MTS could not be reliably distinguished from HGG by the methods investigated. (orig.)

Optimal differentiation of high- and low-grade glioma and metastasis: a meta-analysis of perfusion, diffusion, and spectroscopy metrics

International Nuclear Information System (INIS)

Usinskiene, Jurgita; Venius, Jonas; Rynkeviciene, Ryte; Norkus, Darius; Suziedelis, Kestutis; Ulyte, Agne; Bjoernerud, Atle; Katsaros, Vasileios K.; Letautiene, Simona; Aleknavicius, Eduardas; Rocka, Saulius; Usinskas, Andrius

2016-01-01

To perform a meta-analysis of advanced magnetic resonance imaging (MRI) metrics, including relative cerebral blood volume (rCBV), normalized apparent diffusion coefficient (nADC), and spectroscopy ratios choline/creatine (Cho/Cr) and choline/N-acetyl aspartate (Cho/NAA), for the differentiation of high- and low-grade gliomas (HGG, LGG) and metastases (MTS). For systematic review, 83 articles (dated 2000-2013) were selected from the NCBI database. Twenty-four, twenty-two, and eight articles were included respectively for spectroscopy, rCBV, and nADC meta-analysis. In the meta-analysis, we calculated overall means for rCBV, nADC, Cho/Cr (short TE - from 20 to 35 ms, medium - from 135 to 144 ms), and Cho/NAA for the HGG, LGG, and MTS groups. We used random effects model to obtain weighted averages and select thresholds. Overall means (with 95 % CI) for rCBV, nADC, Cho/Cr (short and medium echo time, TE), and Cho/NAA were: for HGG 5.47 (4.78-6.15), 1.38 (1.16-1.60), 2.40 (1.67-3.13), 3.27 (2.78-3.77), and 4.71 (3.24-6.19); for LGG 2.00 (1.71-2.28), 1.61 (1.36-1.87), 1.46 (1.20-1.72), 1.71 (1.49-1.93), and 2.36 (1.50-3.23); for MTS 5.06 (3.85-6.27), 1.35 (1.06-1.64), 1.89 (1.72-2.06), 3.14 (1.57-4.72), (Cho/NAA was not available). LGG had significantly lower rCBV, Cho/Cr, and Cho/NAA values than HGG or MTS. No significant differences were found for nADC. Best differentiation between HGG and LGG is obtained from rCBV, Cho/Cr, and Cho/NAA metrics. MTS could not be reliably distinguished from HGG by the methods investigated. (orig.)

Resistance exercise with different volumes: blood pressure response and forearm blood flow in the hypertensive elderly

Directory of Open Access Journals (Sweden)

Brito AF

2014-12-01

Full Text Available Aline de Freitas Brito,1 Caio Victor Coutinho de Oliveira,2 Maria do Socorro Brasileiro-Santos,1 Amilton da Cruz Santos1 1Physical Education Department, 2Research Laboratory for Physical Training Applied to Performance and Health, Federal University of Paraíba, João Pessoa, Brazil Background: The purpose of this study was to evaluate the effect of two sessions of resistance exercise with different volumes on post-exercise hypotension, forearm blood flow, and forearm vascular resistance in hypertensive elderly subjects.Methods: The study was conducted with ten hypertensive elderly (65±3 years, 28.7±3 kg/m2 subjected to three experimental sessions, ie, a control session, exercise with a set (S1, and exercise with three sets (S3. For each session, the subjects were evaluated before and after intervention. In the pre-intervention period, blood pressure, forearm blood flow, and forearm vascular resistance were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same time period. Both S1 and S3 comprised a set of ten repetitions of ten exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (post-intervention in the supine position.Results: Post-exercise hypotension was greater in S3 than in S1 (systolic blood pressure, −26.5±4.2 mmHg versus −17.9±4.7 mmHg; diastolic blood pressure, −13.8±4.9 mmHg versus −7.7±5 mmHg, P<0.05. Similarly, forearm blood flow and forearm vascular resistance changed significantly in both sessions with an increase and decrease, respectively, that was more evident in S3 than in S1 (P<0.05.Conclusion: Resistance exercises with higher volume were more effective in causing post-exercise hypotension, being accompanied by an increase in forearm blood flow and a reduction of forearm vascular

A study on the pulmonary mean transit time and the pulmonary blood volume by RI-cardiogram

International Nuclear Information System (INIS)

Ushio, Norio

1987-01-01

The pulmonary mean transit time and the pulmonary blood volume in cases of cardio-pulmonary disease were measured using Giuntini's method which is considered the most appropriate among radiocardiographic methods. The errors in this method were confirmed to be almost negligible. The results obtained were as follows: 1) The pulmonary mean transit time was related to the systemic mean transit time and markedly prolonged in left heart failure. On the other hand, it was markedly shortened in some cases of chronic pulmonary disease, particularly pulmonary emphysema. 2) The pulmonary blood volume tended to increase in left heart disorders and mitral valve disease and tended to decrease in the chronic pulmonary disease. The decrease was conspicuous particularly in some cases of pulmonary emphysema. 3) A structural change of the pulmonary vascular system in the chronic pulmonary disease appeared to bring about shortening of the pulmonary mean transit time and a decrease in the pulmonary blood volume. The pathophysiology of cardio-pulmonary disease can be more clarified by the RI-cardiogram used in this study, in which the pulmonary mean transit time and the pulmonary blood volume are used as the indicator. (author)

Evaluation of the BD BACTEC FX blood volume monitoring system as a continuous quality improvement measure.

Science.gov (United States)

Coorevits, L; Van den Abeele, A-M

2015-07-01

The yield of blood cultures is proportional to the volume of blood cultured. We evaluated an automatic blood volume monitoring system, recently developed by Becton Dickinson within its BACTEC EpiCenter module, that calculates mean volumes of negative aerobic bottles and generates boxplots and histograms. First, we evaluated the filling degree of 339 aerobic glass blood cultures by calculating the weight-based volume for each bottle. A substantial amount of the bottles (48.3%) were inadequately filled. Evaluation of the accuracy of the monitoring system showed a mean bias of -1.4 mL (-15.4%). Additional evaluation, using the amended software on 287 aerobic blood culture bottles, resulted in an acceptable mean deviation of -0.3 mL (-3.3%). The new software version was also tested on 200 of the recently introduced plastic bottles, which will replace the glass bottles in the near future, showing a mean deviation of +2.8 mL (+26.7%). In conclusion, the mean calculated volumes can be used for the training of a single phlebotomist. However, filling problems appear to be masked when using them for phlebotomist groups or on wards. Here, visual interpretation of boxplots and histograms can serve as a useful tool to observe the spread of the filling degrees and to develop a continuous improvement program. Re-adjustment of the software has proven to be necessary for use with plastic bottles. Due to our findings, BD has developed further adjustments to the software for validated use with plastic bottles, which will be released soon.

Blood Volume and Other Hematologic Values in Young Elephant Seals (Mirounga angustirostris)

National Research Council Canada - National Science Library

Simpson, John G; Gilmartin, William G; Ridgway, Sam H

1970-01-01

... (Mirounga angustirostris) by a method that could be accurate to 2 percent. The blood volumes of 7 young northern elephant seals were analyzed using a dilution of radioactive iodinated human serum albumin...

Association of dynamic susceptibility contrast enhanced MR Perfusion parameters with prognosis in elderly patients with glioblastomas

Energy Technology Data Exchange (ETDEWEB)

Jabehdar Maralani, Pejman [University of Toronto, Department of Medical Imaging, Sunnybrook Health Sciences Center, Toronto, ON (Canada); Melhem, Elias R.; Herskovits, Edward H. [University of Maryland Medical Center, Department of Radiology, Baltimore, MD (United States); Wang, Sumei; Voluck, Matthew R.; Learned, Kim O.; Mohan, Suyash [Perelman School of Medicine at University of Pennsylvania, Department of Radiology, Division of Neuroradiology, Philadelphia, PA (United States); Kim, Sang Joon [University of Ulsan Asan Medical Center, Department of Radiology, Songpa-gu, Seoul (Korea, Republic of); O' Rourke, Donald M. [Perelman School of Medicine at University of Pennsylvania, Department of Surgery, Division of Neurosurgery, Philadelphia, PA (United States)

2015-09-15

We aimed to evaluate the prognostic value of dynamic susceptibility contrast (DSC) MR perfusion in elderly patients with glioblastomas (GBM). Thirty five patients aged ≥65 and 35 aged <65 years old, (referred to as elderly and younger, respectively) were included in this retrospective study. The median relative cerebral volume (rCBV) from the enhancing region (rCBV{sub ER-Med}) and immediate peritumoral region (rCBV{sub IPR-Med}) and maximum rCBV from the enhancing region of the tumor (rCBV{sub ER-Max}) were compared and correlated with survival data. Analysis was repeated after rCBVs were dichotomized into high and low values and after excluding elderly patients who did not receive postoperative chemoradiation (34.3 %). Kaplan-Meyer survival curves and parametric and semi-parametric regression tests were used for analysis. All rCBV parameters were higher in elderly compared to younger patients (p < 0.05). After adjustment for age, none were independently associated with shorter survival (p > 0.05). After rCBV dichotomization into high and low values, high rCBV in elderly was independently associated with shorter survival compared to low rCBV in elderly, or any rCBV in younger patients (p < 0.05). rCBV can be an imaging biomarker to identify a subgroup of GBM patients in the elderly with worse prognosis compared to others. (orig.)

Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage

Energy Technology Data Exchange (ETDEWEB)

Fu, Jun; Chen, Wei-jian; Wang, Mei-hao; Li, Jian-ce; Zhang, Qian; Xia, Neng-zhi; Yang, Yun-jun [Wenzhou Medical University, Department of Radiology, First Affiliated Hospital, Wenzhou (China); Wu, Gui-yun [Cleveland Clinics Foundation, Department of Nuclear Medicine, Imaging Institute, Cleveland, OH (United States); Cheng, Jing-liang; Zhang, Yong [Zhengzhou University, Department of Radiology, First Affiliated Hospital, Zhengzhou (China); Zhuge, Qichuan [Wenzhou Medical University, Department of Neurosurgery, First Affiliated Hospital, Wenzhou (China)

2014-11-09

The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∝-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients. (orig.)

Whole-brain 320-detector row dynamic volume CT perfusion detected crossed cerebellar diaschisis after spontaneous intracerebral hemorrhage

International Nuclear Information System (INIS)

Fu, Jun; Chen, Wei-jian; Wang, Mei-hao; Li, Jian-ce; Zhang, Qian; Xia, Neng-zhi; Yang, Yun-jun; Wu, Gui-yun; Cheng, Jing-liang; Zhang, Yong; Zhuge, Qichuan

2015-01-01

The purpose of this study was to evaluate the value of 320-detector row CT used to detect crossed cerebellar diaschisis (CCD) in patients with unilateral supratentorial spontaneous intracerebral hemorrhage (SICH). We investigated 62 of 156 patients with unilateral supratentorial SICH using 320-detector row CT scanning. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), and time to peak (rTTP) levels were measured in different regions of interest (ROIs) that were manually outlined on computed tomography perfusion (CTP) for the cerebrum, including normal-appearing brain tissue that surrounded the perilesional low-density area (NA) and the perihematomal low-density area (PA) in all patients and the cerebellum (ipsilateral and contralateral) in CCD-positive patients. Of 62 cases, a total of 14 met the criteria for CCD due to cerebellar perfusion asymmetry on CTP maps. In the quantitative analysis, significant differences were found in the perfusion parameters between the contralateral and ipsilateral cerebellum in CCD-positive cases. No significant differences were found between the CCD-positive group and the CCD-negative group according to the hematoma volume, NIHSS scores, and cerebral perfusion abnormality (each P > 0.05). The correlation analysis of the degree of NA, PA perfusion abnormality, and the degree of CCD severity showed negative and significant linear correlations (R, -0.66∝-0.56; P < 0.05). 320-detector row CT is a robust and practicable method for the comprehensive primary imaging work-up of CCD in unilateral supratentorial SICH patients. (orig.)

Blood volume, blood pressure and total body sodium: internal signalling and output control

DEFF Research Database (Denmark)

Bie, P

2009-01-01

Total body sodium and arterial blood pressure (ABP) are mutually dependent variables regulated by complex control systems. This review addresses the role of ABP in the normal control of sodium excretion (NaEx), and the physiological control of renin secretion. NaEx is a pivotal determinant of ABP......, and under experimental conditions, ABP is a powerful, independent controller of NaEx. Blood volume is a function of dietary salt intake; however, ABP is not, at least not in steady states. A transient increase in ABP after a step-up in sodium intake could provide a causal relationship between ABP...... and the regulation of NaEx via a hypothetical integrative control system. However, recent data show that subtle sodium loading (simulating salty meals) causes robust natriuresis without changes in ABP. Changes in ABP are not necessary for natriuresis. Normal sodium excretion is not regulated by pressure. Plasma...

Variations in gastric compliance induced by acute blood volume changes in anesthetized rats

Directory of Open Access Journals (Sweden)

Graça J.R.V.

2002-01-01

Full Text Available The impact of acute volume imbalances on gastric volume (GV was studied in anesthetized rats (250-300 g. After cervical and femoral vessel cannulation, a balloon catheter was positioned in the proximal stomach. The opposite end of the catheter was connected to a barostat with an electronic sensor coupled to a plethysmometer. A standard ionic solution was used to fill the balloon (about 3.0 ml and the communicating vessel system, and to raise the reservoir liquid level 4 cm above the animals' xiphoid appendix. Due to constant barostat pressure, GV values were considered to represent the gastric compliance index. All animals were monitored for 90 min. After a basal interval, they were randomly assigned to normovolemic, hypervolemic, hypovolemic or restored protocols. Data were compared by ANOVA followed by Bonferroni's test. Mean arterial pressure (MAP, central venous pressure (CVP and GV values did not change in normovolemic animals (N = 5. Hypervolemic animals (N = 12 were transfused at 0.5 ml/min with a suspension of red blood cells in Ringer-lactate solution with albumin (12.5 ml/kg, which reduced GV values by 11.3% (P0.05. MAP and CVP values increased (P<0.05 after hypervolemia but decreased (P<0.05 with hypovolemia. In conclusion, blood volume level modulates gastric compliance, turning the stomach into an adjustable reservoir, which could be part of the homeostatic process to balance blood volume.

Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

Science.gov (United States)

Baum, K.; Essfeld, D.; Stegemann, J.

To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

The Blood Volume of the Guinea Pig: Effects of Epinephrine and Isoproterenol upon the Red Cell and Plasma Volumes, Heart Rate, and Mean Arterial Pressure,

Science.gov (United States)

1987-09-01

capillaries (4), blood volumes calculated from plasma volume measures must correct for label that has left the system between the time of the injected dose...Splenic sequestration and contraction are mediated by the autonomic nervous system and blood-borne agents (10). Sympathetic nerve fibers from the truncus...sympathlcus and parasympathetic neurons of the nervus vagus (cranial nerve X) innervate the celiac plexus (8, 11). A subdivision of the celiac plexus

Correlation of CT perfusion and CT volumetry in patients with Alzheimers disease

International Nuclear Information System (INIS)

Czarnecka, A.; Zimny, A.; Sasiadek, M.

2010-01-01

Background: Both brain atrophy and decrease of perfusion are observed in dementive diseases. The aim of the study was to correlate the results of brain perfusion CT (pCT) and CT volumetry in patients with Alzheimers disease (AD). Material/Methods: Forty-eight patients with AD (mean age of 71.3 years) underwent brain pCT and CT volumetry. The pCT was performed at the level of basal ganglia after the injection of contrast medium (50 ml, 4 ml/sec.) with serial scanning (delay 7 sec, 50 scans, 1 scan/sec). Volumetric measurements were carried out on the basis of source images, with the use of a dedicated CT software combined with manual outlining of the regions of interest in extracerebral and intraventricular CSF spaces. Perfusion parameters of the cerebral blood flow (CBF) and cerebral blood volume (CBV) from the grey matter of frontal and temporal as well as basal ganglia were compared statistically with the volumetric measurements of frontal and temporal cortical atrophy as well as subcortical atrophy. Results: A statistically significant positive correlation was found between the values of CBF and CBV in the basal ganglia and the volumes of the lateral and third ventricles. The comparison of CBF and CBV results with the volumetric measurements in the areas of the frontal and temporal lobes showed mostly negative correlations, but none of them was of statistical significance. Conclusions: In patients with AD, the degree of cortical atrophy is not correlated with the decrease of perfusion in the grey matter and subcortical atrophy is not correlated with the decrease of perfusion in the basal ganglia region. It suggests that functional and structural changes in AD are not related to each other. (authors)

Quantitative agreement between [(15)O]H2O PET and model free QUASAR MRI-derived cerebral blood flow and arterial blood volume

NARCIS (Netherlands)

Heijtel, D. F. R.; Petersen, E. T.; Mutsaerts, H. J. M. M.; Bakker, E.; Schober, P.; Stevens, M. F.; van Berckel, B. N. M.; Majoie, C. B. L. M.; Booij, J.; van Osch, M. J. P.; van Bavel, E. T.; Boellaard, R.; Lammertsma, A. A.; Nederveen, A. J.

2016-01-01

The purpose of this study was to assess whether there was an agreement between quantitative cerebral blood flow (CBF) and arterial cerebral blood volume (CBVA) measurements by [(15)O]H2O positron emission tomography (PET) and model-free QUASAR MRI. Twelve healthy subjects were scanned within a week

Development of a multichannel optical system for differential cortical measurement

Science.gov (United States)

Maki, Atsushi; Yamashita, Yuichi; Watanabe, Eiju; Koizumi, Hideaki

1997-08-01

A prototype system based on intensity-modulation spectroscopy (IMS) was produced with the goal of developing 'optoencephalography' as a new instrument for clinical application and for investigating human brain functions. This system can use dual wavelengths (787 and 827 nm) to simultaneously measure reflectances at 8 measurement positions on the human head. Using the system, we measured the changes in blood circulation and oxygenation changes caused by epileptic seizures and specific brain functions. The former measurements were made simultaneously with tests to determine the epileptic focus by using single-photon-emission computed tomography (SPECT) and electrodes set in the brian. Four measurement positions were fixed in each temporal region. The areas where cerebral blood flow increased, as observed by SPECT, corresponded to the positions where the regional cerebral blood volume (rCBV) increased, as measured by the IMS system. Furthermore, the timing of the epileptic seizures, as measured by the depth-electrodes, corresponded to the timing of the increase in rCBV measured by the prototype system. Our measurements of changes in blood circulation as a result of brain functions were made for motor functions to compare the differences between the right and left hemisphere in how they respond to specific functions. Four measurement positions were set in bilateral motor areas. Significant differences in blood circulation in connection with brain activities were observed between the right and left hemispheres.

Perfusion MR imaging for differentiation of benign and malignant meningiomas

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hao [University of Groningen, Department of Radiology, University Medical Center Groningen, Groningen (Netherlands); Shanghai Jiaotong University, Department of Radiology, First People' s Hospital, Shanghai (China); Roediger, Lars A.; Oudkerk, Matthijs [University of Groningen, Department of Radiology, University Medical Center Groningen, Groningen (Netherlands); Shen, Tianzhen [Fudan University, Department of Radiology, Huashan Hospital, Shanghai (China); Miao, Jingtao [Shanghai Jiaotong University, Department of Radiology, First People' s Hospital, Shanghai (China)

2008-06-15

Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. A total of 33 patients with preoperative meningiomas (25 benign and 8 malignant) underwent conventional and dynamic susceptibility contrast perfusion MR imaging. Maximal relative cerebral blood volume (rCBV) and the corresponding relative mean time to enhance (rMTE) (relative to the contralateral normal white matter) in both tumor parenchyma and peritumoral edema were measured. The independent samples t-test was used to determine whether there was a statistically significant difference in the mean rCBV and rMTE ratios between benign and malignant meningiomas. The mean maximal rCBV values of benign and malignant meningiomas were 7.16{+-}4.08 (mean{+-}SD) and 5.89{+-}3.86, respectively, in the parenchyma, and 1.05{+-}0.96 and 3.82{+-}1.39, respectively, in the peritumoral edema. The mean rMTE values were 1.16{+-}0.24 and 1.30{+-}0.32, respectively, in the parenchyma, and 0.91{+-}0.25 and 1.24{+-}0.35, respectively, in the peritumoral edema. The differences in rCBV and rMTE values between benign and malignant meningiomas were not statistically significant (P>0.05) in the parenchyma, but both were statistically significant (P<0.05) in the peritumoral edema. Perfusion MR imaging can provide useful information on meningioma vascularity which is not available from conventional MRI. Measurement of maximal rCBV and corresponding rMTE values in the peritumoral edema is useful in the preoperative differentiation between benign and malignant meningiomas. (orig.)

The utility of first-pass perfusion CT in hyperacute ischemic stroke: early experience

International Nuclear Information System (INIS)

Lee, Tae Jin; Lee, Myeong Sub; Kim, Myung Soon; Hong, In Soo; Lee, Young Han; Lee, Ji Yong; Whang, Kum

2003-01-01

To evaluate the findings of first-pass perfusion CT in hyperacute stroke patients and to determine the relationship between a perfusion map and final infarct outcome. Thirty-five patients admitted with ischemic stroke within six hours of the onset of symptoms underwent conventional cerebral CT immediately followed by first-pass perfusion CT. Nineteen underwent follow-up CT or MRI, and three types of dynamic perfusion map-cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) - were evaluated by two radiologists. In these 19 patients, initial perfusion maps correlated with final infarct size, determined during follow-up studies. In all 35 patients, major large vessel perfusion abnormalities [middle cerebral artery - MCA MCA and anterior cerebral artery - ACA (n=2); posterior cerebral artery - PCA (n=8)] were detected. On first-pass perfusion maps depicting CBF and MTT, all lesions were detected, and CBF and delayed MTT values were recorded. CBV maps showed variable findings. In all 19 patients who were followed up, the final infarct size of perfusion abnormalities was less than that depicted on CBF and MTT maps, and similar to or much greater than that seen on CBV maps. First-pass perfusion CT scanning is a practical, rapid and advanced imaging technique. In hyperacute stroke patients, it provides important and reliable hemodynamic information as to which brain tissue is salvageable by thrombolytic therapy, and predicts outcome of such treatment

Multichannel optical brain imaging to separate cerebral vascular, tissue metabolic, and neuronal effects of cocaine

Science.gov (United States)

Ren, Hugang; Luo, Zhongchi; Yuan, Zhijia; Pan, Yingtian; Du, Congwu

2012-02-01

Characterization of cerebral hemodynamic and oxygenation metabolic changes, as well neuronal function is of great importance to study of brain functions and the relevant brain disorders such as drug addiction. Compared with other neuroimaging modalities, optical imaging techniques have the potential for high spatiotemporal resolution and dissection of the changes in cerebral blood flow (CBF), blood volume (CBV), and hemoglobing oxygenation and intracellular Ca ([Ca2+]i), which serves as markers of vascular function, tissue metabolism and neuronal activity, respectively. Recently, we developed a multiwavelength imaging system and integrated it into a surgical microscope. Three LEDs of λ1=530nm, λ2=570nm and λ3=630nm were used for exciting [Ca2+]i fluorescence labeled by Rhod2 (AM) and sensitizing total hemoglobin (i.e., CBV), and deoxygenated-hemoglobin, whereas one LD of λ1=830nm was used for laser speckle imaging to form a CBF mapping of the brain. These light sources were time-sharing for illumination on the brain and synchronized with the exposure of CCD camera for multichannel images of the brain. Our animal studies indicated that this optical approach enabled simultaneous mapping of cocaine-induced changes in CBF, CBV and oxygenated- and deoxygenated hemoglobin as well as [Ca2+]i in the cortical brain. Its high spatiotemporal resolution (30μm, 10Hz) and large field of view (4x5 mm2) are advanced as a neuroimaging tool for brain functional study.

Does Preinterventional Flat-Panel Computer Tomography Pooled Blood Volume Mapping Predict Final Infarct Volume After Mechanical Thrombectomy in Acute Cerebral Artery Occlusion?

International Nuclear Information System (INIS)

Wagner, Marlies; Kyriakou, Yiannis; Mesnil de Rochemont, Richard du; Singer, Oliver C.; Berkefeld, Joachim

2013-01-01

PurposeDecreased cerebral blood volume is known to be a predictor for final infarct volume in acute cerebral artery occlusion. To evaluate the predictability of final infarct volume in patients with acute occlusion of the middle cerebral artery (MCA) or the distal internal carotid artery (ICA) and successful endovascular recanalization, pooled blood volume (PBV) was measured using flat-panel detector computed tomography (FPD CT).Materials and MethodsTwenty patients with acute unilateral occlusion of the MCA or distal ACI without demarcated infarction, as proven by CT at admission, and successful Thrombolysis in cerebral infarction score (TICI 2b or 3) endovascular thrombectomy were included. Cerebral PBV maps were acquired from each patient immediately before endovascular thrombectomy. Twenty-four hours after recanalization, each patient underwent multislice CT to visualize final infarct volume. Extent of the areas of decreased PBV was compared with the final infarct volume proven by follow-up CT the next day.ResultsIn 15 of 20 patients, areas of distinct PBV decrease corresponded to final infarct volume. In 5 patients, areas of decreased PBV overestimated final extension of ischemia probably due to inappropriate timing of data acquisition and misery perfusion.ConclusionPBV mapping using FPD CT is a promising tool to predict areas of irrecoverable brain parenchyma in acute thromboembolic stroke. Further validation is necessary before routine use for decision making for interventional thrombectomy

Blood Volume: Importance and Adaptations to Exercise Training, Environmental Stresses and Trauma Sickness

Science.gov (United States)

2000-02-01

because of limb atrophy, weight loss, and inactivity) because erythro- cyte levels of 2,3- diphosphoglycerate (2,3-DPG) were in- creased. However...blood volume expansion during exercise training may partially be explained by factors such as initial fitness level , training intensity, exercise mode...335 and their hydration level when measurements are made (131). Plasma volume expansion seems to be greatest when performing upright exercise on about

Errors of the backextrapolation method in determination of the blood volume

Science.gov (United States)

Schröder, T.; Rösler, U.; Frerichs, I.; Hahn, G.; Ennker, J.; Hellige, G.

1999-01-01

Backextrapolation is an empirical method to calculate the central volume of distribution (for example the blood volume). It is based on the compartment model, which says that after an injection the substance is distributed instantaneously in the central volume with no time delay. The occurrence of recirculation is not taken into account. The change of concentration with time of indocyanine green (ICG) was observed in an in vitro model, in which the volume was recirculating in 60 s and the clearance of the ICG could be varied. It was found that the higher the elimination of ICG, the higher was the error of the backextrapolation method. The theoretical consideration of Schröder et al ( Biomed. Tech. 42 (1997) 7-11) was proved. If the injected substance is eliminated somewhere in the body (i.e. not by radioactive decay), the backextrapolation method produces large errors.

Prediction of hemorrhagic transformation in acute ischemic stroke using permeability surface of CT perfusion

International Nuclear Information System (INIS)

Xiong Bing; Chen Weijian; Fufengli

2012-01-01

Objective: To investigate the value of permeability surface (PS) in predicting hemorrhagic transformation (HT) in acute ischernic stroke (AIS) using CT perfusion (CTP). Methods: The study included 31 consecutive patients who presented symptoms suggestive of an AIS for 3-9 h. All patients underwent CT examination (noncontrast CT, CTP). HT was determined by follow-up CT images. According to presence of HT, the AIS was divided into HT group (PS HT , 11 patients) and non-HT group (PS No-HT , 20 patients). PS, cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) on both sides of brains were measured.The relative PS (rPS), relative CBF (rCBF), relative CBV (rCBV) and relative MTT(rMTT) were obtained by calculating the ratio of the values of bilateral regions. The rPS between PS HT and PS No-HT was compared with an exact Wilcoxon signed-rank test. The rCBF, rCBV, rMTT and the PS of the ischemic side between PS HT and PS No-HT were compared with independent-sample t test. Meanwhile, Spearman rank correlation analysis was conducted to analyze the relationship between the CTP parameters and HT. Results: The PS value of ischemic side was (1.61 ±0.77) ml · min -1 · 100 g -1 for the PS HT group,and the value was (0.91 ± 0.49) ml · min -1 · 100 g -1 for the PS No-HT group. For the PS HT group, rPS, rCBF, rCBV, rMTT were 2.76 ±0.78, 0.32 ±0.18, 0.66 ±0.31, 2.67 ±0.71, and for the PS No-HT group, rPS, rCBF, rCBV, rMTT were 1.35 ±0.19, 0.50±0.21, 0.91 ±0.28, 2.62 ± 1.31. Compared with PS No-HT ,PS HT had higher rPS and PS value,and there were significant statistical differences (U=0.000, t=3.070, P<0.01). But rCBF and rCBV values were lower in the PS HT group compared to the PS No-HT group, and there were significant statistical differences (t rCBF =2.343, t rCBV =2.210, P<0.05). There was no significant statistical difference in rMTT between the two groups (t=0.118, P>0.05). Significant positive correlations were detected between the r

Intraprocedural blood volume measurement using C-arm CT as a predictor for treatment response of malignant liver tumours undergoing repetitive transarterial chemoembolization (TACE)

International Nuclear Information System (INIS)

Vogl, Thomas J.; Schaefer, Patrik; Lehnert, Thomas; Mbalisike, Emmanuel; Hammerstingl, Renate; Eichler, Katrin; Zangos, Stephan; Nour-Eldin, Nour-Eldin A.; Ackermann, Hanns; Naguib, Nagy N.N.

2016-01-01

To evaluate feasibility of measuring parenchymal blood volume (PBV) of malignant hepatic tumours using C-arm CT, test the changes in PBV following repeated transarterial chemoembolization (TACE) and correlate these changes with the change in tumour size in MRI. 111 patients with liver malignancy were included. Patients underwent MRI and TACE in a 4- to 6-week interval. During intervention C-arm CT was performed. Images were post-processed to generate PBV maps. Blood volume data in C-arm CT and change in size in MRI were evaluated. The correlation between PBV and size was tested using Spearman rank test. Pre-interventional PBV maps showed a mean blood volume of 84.5 ml/1000 ml ± 62.0, follow-up PBV maps after multiple TACE demonstrated 61.1 ml/1000 ml ± 57.5. The change in PBV was statistically significant (p = 0.02). Patients with initial tumour blood volume >100 ml/1000 ml dropped 7.1 % in size and 47.2 % in blood volume; 50-100 ml/1000 ml dropped 4.6 % in size and 25.7 % in blood volume; and <50 ml/1000 ml decreased 2.8 % in size and increased 82.2 % in blood volume. PBV measurement of malignant liver tumours using C-arm CT is feasible. Following TACE PBV decreased significantly. Patients with low initial PBV show low local response rates and further increase in blood volume, whereas high initial tumour PBV showed better response to TACE. (orig.)

Using Hematology Data from Malaria Vaccine Research Trials in Humans and Rhesus Macaques (Macaca mulatta) To Guide Volume Limits for Blood Withdrawal.

Science.gov (United States)

Hegge, Sara R; Hickey, Bradley W; Mcgrath, Shannon M; Stewart, V Ann

2016-12-01

Guidelines on safe volume limits for blood collection from research participants in both humans and laboratory animals vary widely between institutions. The main adverse event that may be encountered in large blood volume withdrawal is iron-deficiency anemia. Monitoring various parameters in a standard blood panel may help to prevent this outcome. To this end, we analyzed the Hgb and MCV values from 43 humans and 46 macaques in malaria vaccine research trials. Although the percentage of blood volume removed was greater for macaques than humans, macaques demonstrated an overall increase of MCV over time, indicating the ability to respond appropriately to frequent volume withdrawals. In contrast, humans showed a consistent declining trend in MCV. These declines in human MCV and Hgb were significant from the beginning to end of the study despite withdrawals that were smaller than recommended volume limits. Limiting the volume withdrawn to no more than 12.5% seemed to be sufficient for macaques, and at 14% or more individual animals tended to fail to respond appropriately to large-volume blood loss, as demonstrated by a decrease in MCV. The overall positive erythropoietic response seen in macaques was likely due to the controlled, iron-fortified diet they received. The lack of erythropoietic response in the human subjects may warrant iron supplementation or reconsideration of current blood volume withdrawal guidelines.

Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

Energy Technology Data Exchange (ETDEWEB)

Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

2016-08-15

In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

Prediction of Packed Cell Volume after Whole Blood Transfusion in Small Ruminants and South American Camelids: 80 Cases (2006–2016)

OpenAIRE

Luethy, D.; Stefanovski, D.; Salber, R.; Sweeney, R.W.

2017-01-01

Background Calculation of desired whole blood transfusion volume relies on an estimate of an animal's circulating blood volume, generally accepted to be 0.08 L/kg or 8% of the animal's body weight in kilograms. Objective To use packed cell volume before and after whole blood transfusion to evaluate the accuracy of a commonly used equation to predict packed cell volume after transfusion in small ruminants and South American camelids; to determine the nature and frequency of adverse transfusion...

Reduced left ventricular filling following blood volume extraction does not result in compensatory augmentation of cardiac mechanics.

Science.gov (United States)

Lord, Rachel; MacLeod, David; George, Keith; Oxborough, David; Shave, Rob; Stembridge, Mike

2018-04-01

What is the central question of this study? A reduction in left ventricular (LV) filling, and concomitant increase in heart rate, augments LV mechanics to maintain stroke volume (SV); however, the impact of reduced LV filling in isolation on SV and LV mechanics is currently unknown. What is the main finding and its importance? An isolated decrease in LV filling did not provoke a compensatory increase in mechanics to maintain SV; in contrast, LV mechanics and SV were reduced. These data indicate that when LV filling is reduced without changes in heart rate, LV mechanics do not compensate to maintain SV. An acute non-invasive reduction in preload has been shown to augment cardiac mechanics to maintain stroke volume and cardiac output. Such interventions induce concomitant changes in heart rate, whereas blood volume extraction reduces preload without changes in heart rate. Therefore, the purpose of this study was to determine whether a preload reduction in isolation resulted in augmented stroke volume achieved via enhanced cardiac mechanics. Nine healthy volunteers (four female, age 29 ± 11 years) underwent echocardiography for the assessment of left ventricular (LV) volumes and mechanics in a supine position at baseline and end extraction after the controlled removal of 25% of total blood volume (1062 ± 342 ml). Arterial blood pressure was monitored continuously by a pressure transducer attached to an indwelling radial artery catheter. Heart rate and total peripheral resistance were unchanged from baseline to end extraction, but systolic blood pressure was reduced (from 148 to 127 mmHg). From baseline to end extraction there were significant reductions in left ventricular end-diastolic volume (from 89 to 71 ml) and stroke volume (from 56 to 37 ml); however, there was no change in LV twist, basal or apical rotation. In contrast, LV longitudinal strain (from -20 to -17%) and basal circumferential strain (from -22 to -19%) were significantly reduced from

Revisiting the Logan plot to account for non-negligible blood volume in brain tissue.

Science.gov (United States)

Schain, Martin; Fazio, Patrik; Mrzljak, Ladislav; Amini, Nahid; Al-Tawil, Nabil; Fitzer-Attas, Cheryl; Bronzova, Juliana; Landwehrmeyer, Bernhard; Sampaio, Christina; Halldin, Christer; Varrone, Andrea

2017-08-18

Reference tissue-based quantification of brain PET data does not typically include correction for signal originating from blood vessels, which is known to result in biased outcome measures. The bias extent depends on the amount of radioactivity in the blood vessels. In this study, we seek to revisit the well-established Logan plot and derive alternative formulations that provide estimation of distribution volume ratios (DVRs) that are corrected for the signal originating from the vasculature. New expressions for the Logan plot based on arterial input function and reference tissue were derived, which included explicit terms for whole blood radioactivity. The new methods were evaluated using PET data acquired using [ 11 C]raclopride and [ 18 F]MNI-659. The two-tissue compartment model (2TCM), with which signal originating from blood can be explicitly modeled, was used as a gold standard. DVR values obtained for [ 11 C]raclopride using the either blood-based or reference tissue-based Logan plot were systematically underestimated compared to 2TCM, and for [ 18 F]MNI-659, a proportionality bias was observed, i.e., the bias varied across regions. The biases disappeared when optimal blood-signal correction was used for respective tracer, although for the case of [ 18 F]MNI-659 a small but systematic overestimation of DVR was still observed. The new method appears to remove the bias introduced due to absence of correction for blood volume in regular graphical analysis and can be considered in clinical studies. Further studies are however required to derive a generic mapping between plasma and whole-blood radioactivity levels.

Blood products, volume control, and renal support in the coagulopathy of liver disease.

Science.gov (United States)

Argo, Curtis K; Balogun, Rasheed A

2009-02-01

Plasma-based products are commonly used in patients who have chronic liver disease to treat perceived coagulopathy despite unproven efficacy and potentially severe risks, such as transfusion-related acute lung injury, which carries a high mortality rate. Moreover, volume expansion may acutely worsen portal hypertension and increase bleeding from the collateral portal vascular bed. Although factor replacement therapy may be warranted in selected situations, its use should be restricted because of the limitations of target tests, such as international normalized ratio, which poorly reflects presence of bleeding diatheses in patients who have cirrhosis. Renal replacement therapies are frequent adjuncts in patients who have cirrhosis and are acutely decompensated, and may correct uremia-related bleeding diathesis and assist in controlling vascular volume, although they are generally limited to use as a bridge to liver transplantation. Novel extracorporeal therapies are emerging and may also have significant interaction with the hemostatic system. Volume contraction and blood conservation therapies are relatively new and promising approaches to reduce use of blood products in liver transplantation.

Scintigraphic method for evaluating reductions in local blood volumes in human extremities

DEFF Research Database (Denmark)

Blønd, L; Madsen, Jan Lysgård

2000-01-01

were carried out. No significant differences between results obtained by the use of one or two scintigraphic projections were found. The between-subject coefficient of variation was 14% in the lower limb experiment and 11% in the upper limb experiment. The within-subject coefficient of variation was 6......% in the lower limb experiment and 6% in the upper limb experiment. We found a significant relation (r = 0.42, p = 0.018) between the results obtained by the scintigraphic method and the plethysmographic method. In fractions, a mean reduction in blood volume of 0.49+0.14 (2 SD) was found after 1 min of elevation...... of the lower limb and a mean reduction of 0.45+/-0.10 (2 SD) after half a minute of elevation of the upper limb. We conclude that the method is precise and can be used in investigating physiologic and pathophysiologic mechanisms in relation to blood volumes of limbs not subject to research previously....

Multimodal MRI in the characterization of glial neoplasms: the combined role of single-voxel MR spectroscopy, diffusion imaging and echo-planar perfusion imaging

International Nuclear Information System (INIS)

Zonari, Paolo; Baraldi, Patrizia; Crisi, Girolamo

2007-01-01

Diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI) and MR spectroscopy (MRS) provide useful data for tumor evaluation. To assess the contribution of these multimodal techniques in grading glial neoplasms, we compared the value of DWI, PWI and MRS in the evaluation of histologically proven high- and low-grade gliomas in a population of 105 patients. Independently for each modality, the following variables were used to compare the tumors: minimum apparent diffusion coefficient (ADC) and maximum relative cerebral blood volume (rCBV) normalized values between tumor and healthy tissue, maximum Cho/Cr ratio and minimum NAA/Cr ratio in tumor, and scored lactate and lipid values in tumor. The Mann-Whitney and Wilcoxon tests were employed to compare DWI, PWI and MRS between tumor types. Logistic regression analysis was used to determine which parameters best increased the diagnostic accuracy in terms of sensitivity, specificity, and positive and negative predictive values. ROC curves were determined for parameters with high sensitivity and specificity to identify threshold values to separate high- from low-grade lesions. Statistically significant differences were found for rCBV tumor/normal tissue ratio, and NAA/Cr ratio in tumor and Cho/Cr ratio in tumor between low- and high-grade tumors. The best performing single parameter for group classification was the normalized rCBV value; including all parameters, statistical significance was reached by rCBV tumor/normal tissue ratio, NAA/Cr tumor ratio and lactate. From the ROC curves, a high probability for a neoplasm to be a high-grade lesion was associated with a rCBV tumor/normal tissue ratio of >1.16 and NAA/Cr tumor ratio of <0.44. Combining PWI and MRS with conventional MR imaging increases the accuracy of the attribution of malignancy to glial neoplasms. The best performing parameter was found to be the perfusion level. (orig.)

Perfusion MR imaging for differentiation of benign and malignant meningiomas

International Nuclear Information System (INIS)

Zhang, Hao; Roediger, Lars A.; Oudkerk, Matthijs; Shen, Tianzhen; Miao, Jingtao

2008-01-01

Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. A total of 33 patients with preoperative meningiomas (25 benign and 8 malignant) underwent conventional and dynamic susceptibility contrast perfusion MR imaging. Maximal relative cerebral blood volume (rCBV) and the corresponding relative mean time to enhance (rMTE) (relative to the contralateral normal white matter) in both tumor parenchyma and peritumoral edema were measured. The independent samples t-test was used to determine whether there was a statistically significant difference in the mean rCBV and rMTE ratios between benign and malignant meningiomas. The mean maximal rCBV values of benign and malignant meningiomas were 7.16±4.08 (mean±SD) and 5.89±3.86, respectively, in the parenchyma, and 1.05±0.96 and 3.82±1.39, respectively, in the peritumoral edema. The mean rMTE values were 1.16±0.24 and 1.30±0.32, respectively, in the parenchyma, and 0.91±0.25 and 1.24±0.35, respectively, in the peritumoral edema. The differences in rCBV and rMTE values between benign and malignant meningiomas were not statistically significant (P>0.05) in the parenchyma, but both were statistically significant (P<0.05) in the peritumoral edema. Perfusion MR imaging can provide useful information on meningioma vascularity which is not available from conventional MRI. Measurement of maximal rCBV and corresponding rMTE values in the peritumoral edema is useful in the preoperative differentiation between benign and malignant meningiomas. (orig.)

Assessment of brain perfusion with MRI: methodology and application to acute stroke

International Nuclear Information System (INIS)

Grandin, C.B.

2003-01-01

We review the methodology of brain perfusion measurements with MRI and their application to acute stroke, with particular emphasis on the work awarded by the 6th Lucien Appel Prize for Neuroradiology. The application of the indicator dilution theory to the dynamic susceptibility-weighted bolus-tracking method is explained, as is the approach to obtaining quantitative measurements of cerebral blood flow (CBF) and volume (CBV). Our contribution to methodological developments, such as CBV measurement with the frequency-shifted burst sequence, development of the PRESTO sequence, comparison of different deconvolution methods and of spin- and gradient-echo sequences, and the validation of MRI measurements against positron emission tomography is summarised. The pathophysiology of brain ischaemia and the role of neuroimaging in the setting of acute stroke are reviewed, with an introduction to the concepts of ischaemic penumbra and diffusion/perfusion mismatch. Our work on the determination of absolute CBF and CBV thresholds for predicting the area of infarct growth, identification of the best perfusion parameters (relative or absolute) for predicting the area of infarct growth and the role of MR angiography is also summarised. We conclude that MRI is a very powerful way to assess brain perfusion and that its use might help in selecting patients who will benefit most from treatment such as thrombolysis. (orig.)

Dynamic Contrast-Enhanced Computed Tomography-Derived Blood Volume and Blood Flow Correlate With Patient Outcome in Metastatic Renal Cell Carcinoma

DEFF Research Database (Denmark)

Mains, Jill Rachel; Donskov, Frede; Pedersen, Erik Morre

2017-01-01

= 7). Using a prototype software program (Advanced Perfusion and Permeability Application, Philips Healthcare, Best, the Netherlands), blood volume (BV), blood flow (BF), and permeability surface area product (PS) were calculated for each tumor at baseline, week 5, and week 10. These parameters......OBJECTIVES: The aim was to explore the potential for using dynamic contrast-enhanced computed tomography as a noninvasive functional imaging biomarker before and during the early treatment of metastatic renal cell carcinoma (mRCC). MATERIALS AND METHODS: Dynamic contrast-enhanced computed...

Role of dynamic CT perfusion study in evaluating various intracranial space-occupying lesions

International Nuclear Information System (INIS)

Kamble, Ravindra B; Jayakumar, Peruvumba N; Shivashankar, Ravishankar

2015-01-01

Differentiating intracranial mass lesions on CT scan is challenging. The purpose of our study was to determine the perfusion parameters in various intracranial space-occupying lesions (ICSOL), differentiate benign and malignant lesions, and differentiate between grades of gliomas. We performed CT perfusion (CTP) in 64 patients, with age ranging from 17 to 68 years, having space-occupying lesions in brain and calculated relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV). We found significantly lower perfusion in low-grade gliomas as compared to high-grade tumors, lymphoma, and metastases. Similarly in infective lesions, TWT and abscesses showed significantly lower perfusion compared to TOT. In ring enhancing lesions, capsule of TWT showed significantly lower perfusion as compared to abscesses, TOT, and metastases. Thus, in conclusion, infective lesions can be differentiated from tumors like lymphomas, high-grade gliomas, or metastases based on perfusion parameters. The cut off value of rCBV 1.64 can be used to differentiate between low grade and high grade gliomas. However, depending only on perfusion parameters, differentiation between the tumors like lymphomas, high-grade gliomas, and metastases may not be possible

Temporal changes in CT perfusion values before and after cranioplasty in patients without symptoms related to external decompression: a pilot study

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Sarubbo, Silvio [' ' S. Chiara' ' Hospital, Neurosurgery Unit, Department of Neurosciences, Trento (Italy); ' ' S. Anna' ' University Hospital, Department of Medical and Surgical Sciences of Communication and Behavior, Clinics of Neurology, Ferrara (Italy); Latini, Francesco; Cavallo, Michele [' ' S. Anna' ' University Hospital, Neurosurgery Unit, Department of Neuroscience and Rehabilitation, Ferrara (Italy); Ceruti, Stefano [' ' S. Anna' ' University Hospital, Neuroradiology Unit, Department of Neuroscience and Rehabilitation, Ferrara (Italy); Chieregato, Arturo [' ' Careggi' ' University Hospital, Neurocritical Care Unit, Department of Neuroscience, Firenze (Italy); D' Esterre, Christopher [Calgary Univ., Calgary, AB (Canada). Foothills Medical Centre; Western Ontario Univ., London, ON (Canada). Imaging Research Lab.; Lee, Ting-Yim [Western Ontario Univ., London, ON (Canada). Imaging Research Lab.; Western Ontario Univ., London, ON (Canada). Imaging Program; Fainardi, Enrico [' ' S. Anna' ' University Hospital, Neuroradiology Unit, Department of Neuroscience and Rehabilitation, Ferrara (Italy); Azienda Ospedaliera Univ., Ferrara (Italy). Unita Operativa di Neuroradiologia

2014-03-15

Little is known about hemodynamic disturbances affecting cerebral hemispheres in traumatic brain injury (TBI) after cranioplasty. We prospectively investigated six stable TBI patients who underwent cranioplasty more than 90 days after effective decompressive craniectomy. Computerized tomography perfusion (CTP) studies and evaluation of clinical outcome were performed for each patient before cranioplasty and at 7 days and 3 months after surgery. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were measured in multiple cortical circular regions positioned in cranioplasty-treated and contralateral hemispheres. Neither complications associated with cranioplasty nor changes in outcome were observed. On the treated side, CBF and CBV values were higher before and 7 days after cranioplasty than at 3 months after surgery, whereas MTT values were lower at 7 days than at 3 months after surgical treatment. Our results indicate that cortical perfusion progressively declines in the cranioplasty treated hemisphere but remains stable in the contralateral hemisphere after surgery and suggest that CTP can represent a promising tool for a longitudinal analysis of hemodynamic abnormalities occurring in TBI patients after cranioplasty. In addition, these data imply a possible role of cranioplasty in restoring flow to meet the prevailing metabolic demand. (orig.)

Utility of evaluation of cerebral circulation for brain-oriented intensive care

International Nuclear Information System (INIS)

Honda, Mitsuru; Sakata, Yoshihito; Ichibayashi, Ryo; Yoshihara, Katsunori; Noguchi, Yoshitaka; Seiki, Yoshikatsu; Machida, Keiichi; Sase, Shigeru

2007-01-01

Severe traumatic brain injury is widely known to cause a dynamic change in CBF. Especially, a decrease in cerebral blood flow (CBF) has been reported. In the present study we measured CBF, mean transit time (MTT) and cerebral blood volume (CBV). Our purpose was to investigate the possibility to estimate the outcome and severity by using these physiological parameters and the utility of cerebral circulation evaluation for brain-oriented intensive care. In 54 patients with traumatic brain injury, Xe-CT and perfusion CT were performed at the same time in the phase II (Day 1-3). We measured CBF by using Xe-CT and MTT by using Perfusion CT and calculated CBV by using AZ-7000 W 98 computer system. The results were correlated with the outcome and the values of CBF and MTT. Significant differences in CBF and MTT were found between a favorable outcome group and a poor outcome group. We could evaluate the condition of cerebral circulation for patients with traumatic brain injury by analyzing the values of CBF and MTT. In conclusion, these parameters can be helpfull for the optimal management and outcome improvement for the patients with severe traumatic brain injury. (author)

Temporal changes in CT perfusion values before and after cranioplasty in patients without symptoms related to external decompression: a pilot study

International Nuclear Information System (INIS)

Sarubbo, Silvio; Latini, Francesco; Cavallo, Michele; Ceruti, Stefano; Chieregato, Arturo; D'Esterre, Christopher; Western Ontario Univ., London, ON; Lee, Ting-Yim; Western Ontario Univ., London, ON; Fainardi, Enrico; Azienda Ospedaliera Univ., Ferrara

2014-01-01

Little is known about hemodynamic disturbances affecting cerebral hemispheres in traumatic brain injury (TBI) after cranioplasty. We prospectively investigated six stable TBI patients who underwent cranioplasty more than 90 days after effective decompressive craniectomy. Computerized tomography perfusion (CTP) studies and evaluation of clinical outcome were performed for each patient before cranioplasty and at 7 days and 3 months after surgery. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were measured in multiple cortical circular regions positioned in cranioplasty-treated and contralateral hemispheres. Neither complications associated with cranioplasty nor changes in outcome were observed. On the treated side, CBF and CBV values were higher before and 7 days after cranioplasty than at 3 months after surgery, whereas MTT values were lower at 7 days than at 3 months after surgical treatment. Our results indicate that cortical perfusion progressively declines in the cranioplasty treated hemisphere but remains stable in the contralateral hemisphere after surgery and suggest that CTP can represent a promising tool for a longitudinal analysis of hemodynamic abnormalities occurring in TBI patients after cranioplasty. In addition, these data imply a possible role of cranioplasty in restoring flow to meet the prevailing metabolic demand. (orig.)

Role of dynamic CT perfusion study in evaluating various intracranial space-occupying lesions

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Ravindra B Kamble

2015-01-01

Full Text Available Aims: Differentiating intracranial mass lesions on CT scan is challenging. The purpose of our study was to determine the perfusion parameters in various intracranial space-occupying lesions (ICSOL, differentiate benign and malignant lesions, and differentiate between grades of gliomas. Materials and Methods: We performed CT perfusion (CTP in 64 patients, with age ranging from 17 to 68 years, having space-occupying lesions in brain and calculated relative cerebral blood flow (rCBF and relative cerebral blood volume (rCBV. Results: We found significantly lower perfusion in low-grade gliomas as compared to high-grade tumors, lymphoma, and metastases. Similarly in infective lesions, TWT and abscesses showed significantly lower perfusion compared to TOT. In ring enhancing lesions, capsule of TWT showed significantly lower perfusion as compared to abscesses, TOT, and metastases. Conclusion: Thus, in conclusion, infective lesions can be differentiated from tumors like lymphomas, high-grade gliomas, or metastases based on perfusion parameters. The cut off value of rCBV 1.64 can be used to differentiate between low grade and high grade gliomas. However, depending only on perfusion parameters, differentiation between the tumors like lymphomas, high-grade gliomas, and metastases may not be possible.

Whole-brain perfusion CT using a toggling table technique to predict final infarct volume in acute ischemic stroke.

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Schrader, I; Wilk, D; Jansen, O; Riedel, C

2013-09-01

To evaluate how accurately final infarct volume in acute ischemic stroke can be predicted with perfusion CT (PCT) using a 64-MDCT unit and the toggling table technique. Retrospective analysis of 89 patients with acute ischemic stroke who underwent CCT, CT angiography (CTA) and PCT using the "toggling table" technique within the first three hours after symptom onset. In patients with successful thrombolytic therapy (n = 48) and in those without effective thrombolytic therapy (n = 41), the infarct volume and the volume of the penumbra on PCT were compared to the infarct size on follow-up images (CT or MRI) performed within 8 days. The feasibility of complete infarct volume prediction by 8 cm cranio-caudal coverage was evaluated. The correlation between the volume of hypoperfusion on PCT defined by cerebral blood volume reduction and final infarct volume was strongest in patients with successful thrombolytic therapy with underestimation of the definite infarct volume by 8.5 ml on average. The CBV map had the greatest prognostic value. In patients without successful thrombolytic therapy, the final infarct volume was overestimated by 12.1 ml compared to the MTT map on PCT. All infarcts were detected completely. There were no false-positive or false-negative results. Using PCT and the "toggling table" technique in acute stroke patients is helpful for the rapid and accurate quantification of the minimal final infarct and is therefore a prognostic parameter which has to be evaluated in further studies to assess its impact on therapeutic decision. ▶ Using PCT and the “toggling table technique” allows accurate quantification of the infarct core and penumbra. ▶ It is possible to record dynamic perfusion parameters quickly and easily of almost the entire supratentorial brain volume on a 64-slice MDCT unit. ▶ The technique allows identification of those patients who could profit from thrombolytic therapy outside the established time intervals. © Georg Thieme Verlag

Somatosensory evoked changes in cerebral oxygen consumption measured non-invasively in premature neonates

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Roche-Labarbe, Nadege; Fenoglio, Angela; Radakrishnan, Harsha; Kocienski-Filip, Marcia; Carp, Stefan A.; Dubb, Jay; Boas, David A.; Grant, P. Ellen; Franceschini, Maria Angela

2013-01-01

The hemodynamic functional response is used as a reliable marker of neuronal activity in countless studies of brain function and cognition. In newborns and infants, however, conflicting results have appeared in the literature concerning the typical response, and there is little information on brain metabolism and functional activation. Measurement of all hemodynamic components and oxygen metabolism is critical for understanding neurovascular coupling in the developing brain. To this end, we combined multiple near infrared spectroscopy techniques to measure oxy- and deoxy-hemoglobin concentrations, cerebral blood volume (CBV), and relative cerebral blood flow (CBF) in the somatosensory cortex of 6 preterm neonates during passive tactile stimulation of the hand. By combining these measures we estimated relative changes in the cerebral metabolic rate of oxygen consumption (rCMRO2). CBF starts increasing immediately after stimulus onset, and returns to baseline before blood volume. This is consistent with the model of pre-capillary arteriole active dilation driving the CBF response, with a subsequent CBV increase influenced by capillaries and veins dilating passively to accommodate the extra blood. rCMRO2 estimated using the steady-state formulation shows a biphasic pattern: an increase immediately after stimulus onset, followed by a post-stimulus undershoot due to blood flow returning faster to baseline than oxygenation. However, assuming a longer mean transit time from the arterial to the venous compartment, due to the immature vascular system of premature infants, reduces the post-stimulus undershoot and increases the flow/consumption ratio to values closer to adult values reported in the literature. We are the first to report changes in local rCBF and rCMRO2 during functional activation in preterm infants. The ability to measure these variables in addition to hemoglobin concentration changes is critical for understanding neurovascular coupling in the developing

Assessment of the accuracy of a Bayesian estimation algorithm for perfusion CT by using a digital phantom

International Nuclear Information System (INIS)

Sasaki, Makoto; Kudo, Kohsuke; Uwano, Ikuko; Goodwin, Jonathan; Higuchi, Satomi; Ito, Kenji; Yamashita, Fumio; Boutelier, Timothe; Pautot, Fabrice; Christensen, Soren

2013-01-01

A new deconvolution algorithm, the Bayesian estimation algorithm, was reported to improve the precision of parametric maps created using perfusion computed tomography. However, it remains unclear whether quantitative values generated by this method are more accurate than those generated using optimized deconvolution algorithms of other software packages. Hence, we compared the accuracy of the Bayesian and deconvolution algorithms by using a digital phantom. The digital phantom data, in which concentration-time curves reflecting various known values for cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and tracer delays were embedded, were analyzed using the Bayesian estimation algorithm as well as delay-insensitive singular value decomposition (SVD) algorithms of two software packages that were the best benchmarks in a previous cross-validation study. Correlation and agreement of quantitative values of these algorithms with true values were examined. CBF, CBV, and MTT values estimated by all the algorithms showed strong correlations with the true values (r = 0.91-0.92, 0.97-0.99, and 0.91-0.96, respectively). In addition, the values generated by the Bayesian estimation algorithm for all of these parameters showed good agreement with the true values [intraclass correlation coefficient (ICC) = 0.90, 0.99, and 0.96, respectively], while MTT values from the SVD algorithms were suboptimal (ICC = 0.81-0.82). Quantitative analysis using a digital phantom revealed that the Bayesian estimation algorithm yielded CBF, CBV, and MTT maps strongly correlated with the true values and MTT maps with better agreement than those produced by delay-insensitive SVD algorithms. (orig.)

Assessment of the accuracy of a Bayesian estimation algorithm for perfusion CT by using a digital phantom

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Sasaki, Makoto; Kudo, Kohsuke; Uwano, Ikuko; Goodwin, Jonathan; Higuchi, Satomi; Ito, Kenji; Yamashita, Fumio [Iwate Medical University, Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Yahaba (Japan); Boutelier, Timothe; Pautot, Fabrice [Olea Medical, Department of Research and Innovation, La Ciotat (France); Christensen, Soren [University of Melbourne, Department of Neurology and Radiology, Royal Melbourne Hospital, Victoria (Australia)

2013-10-15

A new deconvolution algorithm, the Bayesian estimation algorithm, was reported to improve the precision of parametric maps created using perfusion computed tomography. However, it remains unclear whether quantitative values generated by this method are more accurate than those generated using optimized deconvolution algorithms of other software packages. Hence, we compared the accuracy of the Bayesian and deconvolution algorithms by using a digital phantom. The digital phantom data, in which concentration-time curves reflecting various known values for cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and tracer delays were embedded, were analyzed using the Bayesian estimation algorithm as well as delay-insensitive singular value decomposition (SVD) algorithms of two software packages that were the best benchmarks in a previous cross-validation study. Correlation and agreement of quantitative values of these algorithms with true values were examined. CBF, CBV, and MTT values estimated by all the algorithms showed strong correlations with the true values (r = 0.91-0.92, 0.97-0.99, and 0.91-0.96, respectively). In addition, the values generated by the Bayesian estimation algorithm for all of these parameters showed good agreement with the true values [intraclass correlation coefficient (ICC) = 0.90, 0.99, and 0.96, respectively], while MTT values from the SVD algorithms were suboptimal (ICC = 0.81-0.82). Quantitative analysis using a digital phantom revealed that the Bayesian estimation algorithm yielded CBF, CBV, and MTT maps strongly correlated with the true values and MTT maps with better agreement than those produced by delay-insensitive SVD algorithms. (orig.)

Cerebral perfusion computerized tomography: influence of reference vessels, regions of interest and interobserver variability

International Nuclear Information System (INIS)

Soustiel, Jean F.; Mor, Nadav; Zaaroor, Menashe; Goldsher, Dorith

2006-01-01

There are still no standardized guidelines for perfusion computerized tomography (PCT) analysis. A total of 61 PCT studies were analyzed using either the anterior cerebral artery (ACA) or the middle cerebral artery (MCA) as the arterial reference, and the superior sagittal sinus (SSS) or the vein of Galen (VG) as the venous reference. The sizes of regions of interest (ROI) were investigated comparing PCT results obtained using a hemispheric ROI combined with vascular pixel elimination with those obtained using five smaller ROIs located over the cortex and basal ganglia. In addition, interobserver variations were explored using a standardized protocol. MCA-based measurements of cerebral blood flow (CBF) and blood volume (CBV) were in accordance with those obtained with the ACA except in 16 patients with ischemic stroke, in whom CBF was overestimated by the ipsilateral MCA. Venous maximal intensity was significantly lower with the VG when compared with the SSS, resulting in overestimation of CBF and CBV. However, in 13.3% of patients the VG ROI yielded higher maximal intensities than the SSS ROI. There was no difference in PCT results between hemispheric ROI and averaged separate ROI when vascular pixel elimination was used. Finally, interobserver variations were as high as 11% for CBF and 12% for CBV. The present results suggest that pathological rather than anatomical considerations should dictate the choice of the arterial ROI. For venous ROI, although SSS seems to be adequate in most instances, deep cerebral veins may occasionally generate higher maximal intensities and should therefore be selected. Importantly, significant user-dependency should be taken into account. (orig.)

SVM-based glioma grading. Optimization by feature reduction analysis

International Nuclear Information System (INIS)

Zoellner, Frank G.; Schad, Lothar R.; Emblem, Kyrre E.; Harvard Medical School, Boston, MA; Oslo Univ. Hospital

2012-01-01

We investigated the predictive power of feature reduction analysis approaches in support vector machine (SVM)-based classification of glioma grade. In 101 untreated glioma patients, three analytic approaches were evaluated to derive an optimal reduction in features; (i) Pearson's correlation coefficients (PCC), (ii) principal component analysis (PCA) and (iii) independent component analysis (ICA). Tumor grading was performed using a previously reported SVM approach including whole-tumor cerebral blood volume (CBV) histograms and patient age. Best classification accuracy was found using PCA at 85% (sensitivity = 89%, specificity = 84%) when reducing the feature vector from 101 (100-bins rCBV histogram + age) to 3 principal components. In comparison, classification accuracy by PCC was 82% (89%, 77%, 2 dimensions) and 79% by ICA (87%, 75%, 9 dimensions). For improved speed (up to 30%) and simplicity, feature reduction by all three methods provided similar classification accuracy to literature values (∝87%) while reducing the number of features by up to 98%. (orig.)

Positron emission tomography in minor ischemic stroke using oxygen-15 steady-state technique

International Nuclear Information System (INIS)

Pozzilli, C.; Itoh, M.; Matsuzawa, T.; Fukuda, H.; Abe, Y.; Sato, T.; Takeda, S.; Ido, T.

1987-01-01

A study with positron emission tomography (PET) was performed on 10 patients with ischemic stroke and mild disability. The patients underwent cerebral angiography, x-ray computed tomography (CT) scan and regional cerebral measurements of CBF, CMRO2, oxygen extraction ratio (OER), and cerebral blood volume (CBV). Only minor arterial involvement was detected by angiography. In all patients, PET images of functional defects were more extensive than the corresponding CT hypodensity, and there were statistically significant reductions in CBF, CMRO2, and CBF/CBV ratio as compared with control subjects. Half of the regions analyzed in the affected hemisphere demonstrated a disruption of the normal coupling between CBF and CMRO2 as reflected by OER values significantly higher or lower than those of the corresponding region of the contralateral hemisphere. The pathophysiological pattern of high OER combined with a reduction in CBF proportionally greater than the reduction in CMRO2 was particularly indicative of regional chronic hemodynamic compromise in these patients

SVM-based glioma grading. Optimization by feature reduction analysis

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Zoellner, Frank G.; Schad, Lothar R. [University Medical Center Mannheim, Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Emblem, Kyrre E. [Massachusetts General Hospital, Charlestown, A.A. Martinos Center for Biomedical Imaging, Boston MA (United States). Dept. of Radiology; Harvard Medical School, Boston, MA (United States); Oslo Univ. Hospital (Norway). The Intervention Center

2012-11-01

We investigated the predictive power of feature reduction analysis approaches in support vector machine (SVM)-based classification of glioma grade. In 101 untreated glioma patients, three analytic approaches were evaluated to derive an optimal reduction in features; (i) Pearson's correlation coefficients (PCC), (ii) principal component analysis (PCA) and (iii) independent component analysis (ICA). Tumor grading was performed using a previously reported SVM approach including whole-tumor cerebral blood volume (CBV) histograms and patient age. Best classification accuracy was found using PCA at 85% (sensitivity = 89%, specificity = 84%) when reducing the feature vector from 101 (100-bins rCBV histogram + age) to 3 principal components. In comparison, classification accuracy by PCC was 82% (89%, 77%, 2 dimensions) and 79% by ICA (87%, 75%, 9 dimensions). For improved speed (up to 30%) and simplicity, feature reduction by all three methods provided similar classification accuracy to literature values ({proportional_to}87%) while reducing the number of features by up to 98%. (orig.)

[18F]-FMISO PET study of hypoxia in gliomas before surgery: correlation with molecular markers of hypoxia and angiogenesis

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Bekaert, Lien [CHU de Caen, Department of Neurology, Caen (France); Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Caen, Department of Neurosurgery, Caen (France); CHU de Caen, Service de Neurochirurgie, Caen (France); Valable, Samuel; Collet, Solene; Bordji, Karim; Petit, Edwige; Bernaudin, Myriam [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); Lechapt-Zalcman, Emmanuele [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Caen, Department of Pathology, Caen (France); Ponte, Keven [CHU de Caen, Department of Neurosurgery, Caen (France); Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); Constans, Jean-Marc [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Caen, Department of Neuroradiology, Caen (France); Levallet, Guenaelle [CHU de Caen, Department of Pathology, Caen (France); Branger, Pierre [CHU de Caen, Department of Neurology, Caen (France); Emery, Evelyne [CHU de Caen, Department of Neurosurgery, Caen (France); Manrique, Alain [CHU de Caen, Department of Nuclear Medicine, Caen (France); Barre, Louisa [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/LDM-TEP group, Caen (France); Guillamo, Jean-Sebastien [CHU de Caen, Department of Neurology, Caen (France); Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Nimes, Department of Neurology, Nimes (France)

2017-08-15

Hypoxia in gliomas is associated with tumor resistance to radio- and chemotherapy. However, positron emission tomography (PET) imaging of hypoxia remains challenging, and the validation of biological markers is, therefore, of great importance. We investigated the relationship between uptake of the PET hypoxia tracer [18F]-FMISO and other markers of hypoxia and angiogenesis and with patient survival. In this prospective single center clinical study, 33 glioma patients (grade IV: n = 24, III: n = 3, and II: n = 6) underwent [18F]-FMISO PET and MRI including relative cerebral blood volume (rCBV) maps before surgery. Maximum standardized uptake values (SUVmax) and hypoxic volume were calculated, defining two groups of patients based on the presence or absence of [18F]-FMISO uptake. After surgery, molecular quantification of CAIX, VEGF, Ang2 (rt-qPCR), and HIF-1α (immunohistochemistry) were performed on tumor specimens. [18F]-FMISO PET uptake was closely linked to tumor grade, with high uptake in glioblastomas (GB, grade IV). Expression of biomarkers of hypoxia (CAIX, HIF-1α), and angiogenesis markers (VEGF, Ang2, rCBV) were significantly higher in the [18F]-FMISO uptake group. We found correlations between the degree of hypoxia (hypoxic volume and SUVmax) and expression of HIF-1α, CAIX, VEGF, Ang2, and rCBV (p < 0.01). Patients without [18F]-FMISO uptake had a longer survival time than uptake positive patients (log-rank, p < 0.005). Tumor hypoxia as evaluated by [18F]-FMISO PET is associated with the expression of hypoxia markers on a molecular level and is related to angiogenesis. [18F]-FMISO uptake is a mark of an aggressive tumor, almost always a glioblastoma. Our results underline that [18F]-FMISO PET could be useful to guide glioma treatment, and in particular radiotherapy, since hypoxia is a well-known factor of resistance. (orig.)

Reproducibility of Dynamic Computed Tomography Brain Perfusion Measurements in Patients with Significant Carotid Artery Stenosis

International Nuclear Information System (INIS)

Serafin, Z.; Kotarski, M.; Karolkiewicz, M.; Mindykowski, R.; Lasek, W.; Molski, S.; Gajdzinska, M.; Nowak-Nowacka, A.

2009-01-01

Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and inter examination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Inter examination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and inter examination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The inter examination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the inter examination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver

Reproducibility of Dynamic Computed Tomography Brain Perfusion Measurements in Patients with Significant Carotid Artery Stenosis

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Serafin, Z.; Kotarski, M.; Karolkiewicz, M.; Mindykowski, R.; Lasek, W.; Molski, S.; Gajdzinska, M.; Nowak-Nowacka, A. (Dept. of Radiology and Diagnostic Imaging, and Dept. of General and Vascular Surgery, Nicolaus Copernicus Univ., Collegium Medicum, Bydgoszcz (Poland))

2009-02-15

Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and inter examination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Inter examination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and inter examination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The inter examination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the inter examination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver

[Blood plasma volume dynamics in monkeys during immersion].

Science.gov (United States)

Krotov, V P; Burkovskaia, T E; Dotsenko, M A; Gordeev, Iu V; Nosovskiĭ, A M; Chel'naia, N A

2004-01-01

Dynamics of blood plasma volume (PV) was studied with indirect methods (hematocrit count, hemoglobin, total protein and high-molecular protein) during 9-d immersion of monkeys Macaca mulatta. The animals were donned in waterproof suits, motor restrained in space seat liners and immersed down to the xiphisternum. Two monkeys were immersed in the bath at one time. The suits were changed every day under ketamine (10 mg/kg of body mass). There were two groups with 12 animals in each. The first group was kept in the bath 3 days and the second--9 days. Prior to the experiment, the animals had been trained to stay in the seat liner put down into the dry bath. It was shown that already two days of exposure to the hydrostatic forces (approximately 15 mm Hg) and absence of negative pressure breathing reduced PV by 18-20% on the average in all animals. Subsequent PV dynamics was individual by character; however, PV deficit persisted during 4 days of immersion in the whole group. In this period, albumin filtration was increased significantly, whereas high-molecular protein filtration was increased to a less degree. During the remaining days in immersion PV regained normal values. Ten days of readaptation (reclined positioning of monkeys brought back into cage) raised VP beyond baseline values. This phenomenon can be attributed to the necessity to provide appropriate venous return and sufficient blood supply of organs and tissues following extension of blood vessels capacity.

Relationship between Stroke Volume Variation and Blood Transfusion during Liver Transplantation.

Science.gov (United States)

Choi, Jae Moon; Lee, Yoon Kyung; Yoo, Hwanhee; Lee, Sukyung; Kim, Hee Yeong; Kim, Young-Kug

2016-01-01

Intraoperative blood transfusion increases the risk for perioperative mortality and morbidity in liver transplant recipients. A high stroke volume variation (SVV) method has been proposed to reduce blood loss during living donor hepatectomy. Herein, we investigated whether maintaining high SVV could reduce the need for blood transfusion and also evaluated the effect of the high SVV method on postoperative outcomes in liver transplant recipients. We retrospectively analyzed 332 patients who underwent liver transplantation, divided into control (maintaining blood transfusion requirement and hemodynamic parameters, including SVV, as well as postoperative outcomes, such as incidences of acute kidney injury, durations of postoperative intensive care unit and hospital stay, and rates of 1-year mortality. Mean SVV values were 7.0% ± 1.3% in the control group (n = 288) and 11.2% ± 1.8% in the high SVV group (n = 44). The median numbers of transfused packed red blood cells and fresh frozen plasmas in the high SVV group were significantly lower than those in control group (0 vs. 2 units, P = 0.003; and 0 vs. 3 units, P = 0.033, respectively). No significant between-group differences were observed for postoperative outcomes. Maintaining high SVV can reduce the blood transfusion requirement during liver transplantation without worsening postoperative outcomes. These findings provide insights into improving perioperative management in liver transplant recipients.

STS-42 MS Readdy conducts blood volume test on OV-103's middeck

Science.gov (United States)

1992-01-01

STS-42 Mission Specialist (MS) William F. Readdy, using intravehicular activity (IVA) foot restraints, studies a checklist as he measures the veins in his lower right leg on the middeck of Discovery, Orbiter Vehicle (OV) 103. Readdy uses an electronic monitor and a pair of large blood pressure cuffs that encircle the thigh and calf. Changes in blood volume are determined by inflating the cuffs which then alters the blood pressure. The tone of the veins was monitored before and during the flight and will be measured following the eight-day mission. Behind Readdy are the forward lockers with combuster analyzer, checklists, communications kit assemblies, and spotmeter attached. At Readdy's left is the sleep station along the starboard wall.

Influence of residual oxygen-15-labeled carbon monoxide radioactivity on cerebral blood flow and oxygen extraction fraction in a dual-tracer autoradiographic method.

Science.gov (United States)

Iwanishi, Katsuhiro; Watabe, Hiroshi; Hayashi, Takuya; Miyake, Yoshinori; Minato, Kotaro; Iida, Hidehiro

2009-06-01

Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) are quantitatively measured with PET with (15)O gases. Kudomi et al. developed a dual tracer autoradiographic (DARG) protocol that enables the duration of a PET study to be shortened by sequentially administrating (15)O(2) and C(15)O(2) gases. In this protocol, before the sequential PET scan with (15)O(2) and C(15)O(2) gases ((15)O(2)-C(15)O(2) PET scan), a PET scan with C(15)O should be preceded to obtain CBV image. C(15)O has a high affinity for red blood cells and a very slow washout rate, and residual radioactivity from C(15)O might exist during a (15)O(2)-C(15)O(2) PET scan. As the current DARG method assumes no residual C(15)O radioactivity before scanning, we performed computer simulations to evaluate the influence of the residual C(15)O radioactivity on the accuracy of measured CBF and OEF values with DARG method and also proposed a subtraction technique to minimize the error due to the residual C(15)O radioactivity. In the simulation, normal and ischemic conditions were considered. The (15)O(2) and C(15)O(2) PET count curves with the residual C(15)O PET counts were generated by the arterial input function with the residual C(15)O radioactivity. The amounts of residual C(15)O radioactivity were varied by changing the interval between the C(15)O PET scan and (15)O(2)-C(15)O(2) PET scan, and the absolute inhaled radioactivity of the C(15)O gas. Using the simulated input functions and the PET counts, the CBF and OEF were computed by the DARG method. Furthermore, we evaluated a subtraction method that subtracts the influence of the C(15)O gas in the input function and PET counts. Our simulations revealed that the CBF and OEF values were underestimated by the residual C(15)O radioactivity. The magnitude of this underestimation depended on the amount of C(15)O radioactivity and the physiological conditions. This underestimation

Blood Volume, Plasma Volume and Circulation Time in a High-Energy-Demand Teleost, the Yellowfin Tuna (Thunnus Albacares)

DEFF Research Database (Denmark)

Brill, R.W.; Cousins, K.L.; Jones, D.R.

1998-01-01

We measured red cell space with 51Cr-labeled red blood cells, and dextran space with 500 kDa fluorescein-isothiocyanate-labeled dextran (FITC-dextran), in two groups of yellowfin tuna (Thunnus albacares). Red cell space was 13.8+/-0.7 ml kg-1 (mean +/- s.e.m.) Assuming a whole- body hematocrit...... for albacore (Thunnus alalunga, 82-197 ml kg-1). Plasma volume within the primary circulatory system (calculated from the 51Cr-labeled red blood cell data) was 32.9+/-2.3 ml kg-1. Dextran space was 37.0+/-3.7 ml kg-1. Because 500 kDa FITC-dextran appeared to remain within the vascular space, these data imply...

Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion

International Nuclear Information System (INIS)

Hanson, Eric H.; Roach, Cayce J.; Ringdahl, Erik N.; Wynn, Brad L.; DeChancie, Sean M.; Mann, Nathan D.; Diamond, Alan S.; Orrison, William W.

2011-01-01

Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)

Developmental venous anomalies: appearance on whole-brain CT digital subtraction angiography and CT perfusion

Energy Technology Data Exchange (ETDEWEB)

Hanson, Eric H. [Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); University of Nevada Las Vegas, Department of Health Physics and Diagnostic Sciences, 4505 Maryland Parkway, Box 453037, Las Vegas, NV (United States); Amigenics, Inc, Las Vegas, NV (United States); Roach, Cayce J. [Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); University of Nevada Las Vegas, School of Life Sciences, Las Vegas, NV (United States); Ringdahl, Erik N. [University of Nevada Las Vegas, Department of Psychology, Las Vegas, NV (United States); Wynn, Brad L. [Family Medicine Spokane, Spokane, WA (United States); DeChancie, Sean M.; Mann, Nathan D. [Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); Diamond, Alan S. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); Orrison, William W. [Touro University Nevada College of Osteopathic Medicine, Henderson, NV (United States); University of Nevada Las Vegas, Department of Health Physics and Diagnostic Sciences, 4505 Maryland Parkway, Box 453037, Las Vegas, NV (United States); CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); University of Nevada School of Medicine, Department of Medical Education, Reno, NV (United States)

2011-05-15

Developmental venous anomalies (DVA) consist of dilated intramedullary veins that converge into a large collecting vein. The appearance of these anomalies was evaluated on whole-brain computed tomography (CT) digital subtraction angiography (DSA) and CT perfusion (CTP) studies. CT data sets of ten anonymized patients were retrospectively analyzed. Five patients had evidence of DVA and five age- and sex-matched controls were without known neurovascular abnormalities. CT angiograms, CT arterial-venous views, 4-D CT DSA and CTP maps were acquired on a dynamic volume imaging protocol on a 320-detector row CT scanner. Whole-brain CTP parameters were evaluated for cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT), and delay. DSA was utilized to visualize DVA anatomy. Radiation dose was recorded from the scanner console. Increased CTP values were present in the DVA relative to the unaffected contralateral hemisphere of 48%, 32%, and 26%; and for the control group with matched hemispheric comparisons of 2%, -10%, and 9% for CBF, CBV, and MTT, respectively. Average effective radiation dose was 4.4 mSv. Whole-brain DSA and CTP imaging can demonstrate a characteristic appearance of altered DVA hemodynamic parameters and capture the anomalies in superior cortices of the cerebrum and the cerebellum. Future research may identify the rare subsets of patients at increased risk of adverse outcomes secondary to the altered hemodynamics to facilitate tailored imaging surveillance and application of appropriate preventive therapeutic measures. (orig.)

Functional and morphological effects of diazepam and midazolam on tumor vasculature in the 9L gliosarcoma brain tumor model using dynamic susceptibility contrast MRI: a comparative study

Directory of Open Access Journals (Sweden)

Yan N

2017-10-01

Full Text Available Nuo Yan,1 Yuzhen Zheng,2 Cheng Yang1 1Second Department of Anesthesiology, The Affiliated Hospital to Logistics University of PAP, Tianjin, 2Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin, China Abstract: Antiangiogenic therapy attenuates tumor growth by reducing vascularization. Diazepam (DZP and midazolam (MZL have antiangiogenic properties in human umbilical vein endothelial cells. Thus, we investigated the antiangiogenic activity of DZP and MZL in the rat 9L gliosarcoma brain tumor model. The effect on tumor vasculature was evaluated using dynamic susceptibility contrast magnetic resonance imaging with gradient-echo (GE and spin-echo (SE to assess perfusion parameters, including cerebral blood volume (CBV, cerebral blood flow (CBF, mean transit time (MTT, and mean vessel diameter. The GE-normalized CBF (nCBF in the tumors of untreated controls was significantly lower than that in normal brain tissue, whereas the CBV and MTT were higher. DZP- and MZL-treated rats had higher CBF and lower CBV and MTT values than did untreated controls. The tumor size decreased significantly to 33.5% in DZP-treated rats (P<0.001 and 22.5% in MZL-treated rats (P<0.01 relative to controls. The SE-normalized CBV was lower in DZP-treated (32.9% and MZL-treated (10.6% rats compared with controls. The mean vessel diameter decreased significantly by 32.5% in DPZ-treated and by 24.9% in MZL-treated rats compared with controls (P<0.01. The GE and SE nCBF values were higher in DZP-treated (49.9% and 40.1%, respectively and MZL-treated (41.2% and 32.1%, respectively rats than in controls. The GE- and SE-normalized MTTs were lower in DZP-treated (48.2% and 59.8%, respectively and MZL-treated (40.5% and 51.2%, respectively rats than in controls. Both DZP and MZL had antiangiogenic effects on tumor perfusion and vasculature; however, the antiangiogenic activity of DZP is more promising than that of MZL. Keywords: diazepam, midazolam, 9L gliosarcoma

Improvement of image quality and radiation dose of CT perfusion of the brain by means of low-tube voltage (70 KV)

International Nuclear Information System (INIS)

Li, Zhen-lin; Zhang, Kai; Li, Wang-jiang; Chen, Xian; Wu, Bin; Song, Bin; Li, Hang

2014-01-01

To investigate the feasibility of 70 kV cerebral CT perfusion by comparing image quality and radiation exposure to 80 kV. Thirty patients with suspected cerebral ischemia who underwent dual-source CT perfusion were divided into group A (80 kV, 150 mAs) and group B (70 kV, 150 mAs). Quantitative comparisons were used for maximum enhancement, signal-to-noise index (SNI), and values of cerebral blood flow (CBF), cerebral blood flow (CBV), mean transit time (MTT) on CBF, CBV, and MTT images, and radiation dose from these two groups. Qualitative perfusion images were assessed by two readers. Maximum enhancement for group B was higher than group A (P < 0.05). There were no significant differences between the two groups for SNI on CBF and CBV maps (P = 0.06 - 0.576), but significant differences for MTT when SNI was measured on frontal white matter and temporo-occipital white matter (P < 0.05). There were no differences among values of CBF, CBV, and MTT for both groups (P = 0.251-0.917). Mean image quality score in group B was higher than group A for CBF (P < 0.05), but no differences for CBV (P = 0.542) and MTT (P = 0.962). Radiation dose for group B decreased compared with group A. 70 kV cerebral CT perfusion reduces radiation dose without compromising image quality. (orig.)

Improvement of image quality and radiation dose of CT perfusion of the brain by means of low-tube voltage (70 KV)

Energy Technology Data Exchange (ETDEWEB)

Li, Zhen-lin; Zhang, Kai; Li, Wang-jiang; Chen, Xian; Wu, Bin; Song, Bin [West China Hospital of Sichuan University, Department of Radiology, Chengdu, Sichuan (China); Li, Hang [Sichuan Provincial People' s Hospital, Department of Radiology, Chengdu, Sichuan (China)

2014-08-15

To investigate the feasibility of 70 kV cerebral CT perfusion by comparing image quality and radiation exposure to 80 kV. Thirty patients with suspected cerebral ischemia who underwent dual-source CT perfusion were divided into group A (80 kV, 150 mAs) and group B (70 kV, 150 mAs). Quantitative comparisons were used for maximum enhancement, signal-to-noise index (SNI), and values of cerebral blood flow (CBF), cerebral blood flow (CBV), mean transit time (MTT) on CBF, CBV, and MTT images, and radiation dose from these two groups. Qualitative perfusion images were assessed by two readers. Maximum enhancement for group B was higher than group A (P < 0.05). There were no significant differences between the two groups for SNI on CBF and CBV maps (P = 0.06 - 0.576), but significant differences for MTT when SNI was measured on frontal white matter and temporo-occipital white matter (P < 0.05). There were no differences among values of CBF, CBV, and MTT for both groups (P = 0.251-0.917). Mean image quality score in group B was higher than group A for CBF (P < 0.05), but no differences for CBV (P = 0.542) and MTT (P = 0.962). Radiation dose for group B decreased compared with group A. 70 kV cerebral CT perfusion reduces radiation dose without compromising image quality. (orig.)

ECG-gated blood pool tomography in the determination of left ventricular volume, ejection fraction, and wall motion

International Nuclear Information System (INIS)

Underwood, S.R.; Ell, P.J.; Jarritt, P.H.; Emanuel, R.W.; Swanton, R.H.

1984-01-01

ECG-gated blood pool tomography promises to provide a ''gold standard'' for noninvasive measurement of left ventricular volume, ejection fraction, and wall motion. This study compares these measurements with those from planar radionuclide imaging and contrast ventriculography. End diastolic and end systolic blood pool images were acquired tomographically using an IGE400A rotating gamma camera and Star computer, and slices were reconstructed orthogonal to the long axis of the heart. Left ventricular volume was determined by summing the areas of the slices, and wall motion was determined by comparison of end diastolic and end systolic contours. In phantom experiments this provided an accurate measurement of volume (r=0.98). In 32 subjects who were either normal or who had coronary artery disease left ventricular volume (r=0.83) and ejection fraction (r=0.89) correlated well with those using a counts based planar technique. In 16 of 18 subjects who underwent right anterior oblique X-ray contrast ventriculography, tomographic wall motion agreed for anterior, apical, and inferior walls, but abnormal septal motion which was not apparent by contrast ventriculography, was seen in 12 subjects tomographically. All 12 had disease of the left anterior descending coronary artery and might have been expected to have abnormal septal motion. ECG-gated blood pool tomography can thus determine left ventricular volume and ejection fraction accurately, and provides a global description of wall motion in a way that is not possible from any single planar image

Utility of cerebral circulation evaluation in acute traumatic brain injuries

International Nuclear Information System (INIS)

Honda, Mitsuru; Sakata, Yoshihito; Haga, Daisuke; Nomoto, Jun; Noguchi, Yoshitaka; Seiki, Yoshikatsu; Machida, Keiichi; Sase, Shigeru

2007-01-01

Severe traumatic brain injury (TBI) is well-known to cause dynamic changes in cerebral blood flow (CBF). Specifically, TBI has been reported to cause decreases in cerebral blood flow (CBF). In this study, we measured CBF, mean transit time (MTT) and cerebral blood volume (CBV) after TBI. Our purpose was investigate the possibility of assessing TBI outcome and severity with these physiological parameters, and the clinical utility of cerebral circulation evaluation for brain-oriented intensive care. In 37 patients with TBI, xenon-enhanced CT (Xe-CT) and perfusion CT were performed on days 1-3 post-event (phase II). We measured CBF using Xe-CT and MTT by Perfusion CT and calculated CBV using an AZ-7000W98 computer system. Relative intra cranicol pressure (ICP) and CBF showed significant negative correlations. Relative ICP and MTT showed significant positive correlations. Outcomes, correlated with valuse of CBF and MIT. Significant differences in CBF and MTT were found between favorable outcome group (good recovery (GR) and moderate disability (MD)) and poor outcome group (severe disability (SD), vegetative state (VS), and dead (D)). We could estimate the outcome of patients after TBI by analyzing values of CBF and MTT with a probability of 74%. We evaluated cerebral circulation status in patients with TBI by CBF and MTT. These tests can help to optimize management and improve outcome in patients with severe TBI. (author)

Quantified measurement of brain blood volume: comparative evaluations between the single photon emission computer tomography and the positron computer tomography

International Nuclear Information System (INIS)

Bouvard, G.; Fernandez, Y.; Petit-Taboue, M.C.; Derlon, J.M.; Travere, J.M.; Le Poec, C.

1991-01-01

The quantified measurement of cerebral blood volume is interesting for the brain blood circulation studies. This measurement is often used in positron computed tomography. It's more difficult in single photon emission computed tomography: there are physical problems with the limited resolution of the detector, the Compton effect and the photon attenuation. The objectif of this study is to compare the results between these two techniques. The quantified measurement of brain blood volume is possible with the single photon emission computer tomogragry. However, there is a loss of contrast [fr

Determination of the total blood volume of the rat using chromium 51 (1962); Determination du volume sanguin total chez le rat a l'aide du chrome 51 (1962)

Energy Technology Data Exchange (ETDEWEB)

Bernard, Y; Rinaldi, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1962-07-01

In various experiments it is important that the rat's blood volume should be known and it is essential that it could be worked out by simply weighing the animal. Therefore authors decided to work out systematically with chromium 51 blood volume for rats with different weights. Results have shown that blood volume for 100 g is 5.55 ml and that it does not seen to vary with the weight of animals. (authors) [French] La connaissance de la masse sanguine chez le rat est indispensable dans de nombreuses experiences et il est essentiel de pouvoir l'evaluer apres une simple pesee de l'animal. C'est dans ce but que les auteurs ont entrepris la determination systematique de la masse sanguine a l'aide du chrome 51 chez des rats de poids differents. Les resultats obtenus ont montre que la masse sanguine rapportee a 100 grammes d'animal est de 5,53 millilitres, et qu'elle ne parait pas varier avec le poids de l'animal. (auteurs)

The effect of intralesional steroid injections on the volume and blood flow in periocular capillary haemangiomas.

Science.gov (United States)

Verity, David H; Rose, Geoffrey E; Restori, M

2008-01-01

To examine the effect of steroid therapy on the volume estimates and blood flow characteristics of childhood periorbital capillary haemangiomas. Children at risk of amblyopia due to periorbital haemangiomas were treated with intralesional steroid injections (between 1 and 4 courses) and serial assessment of the volume and blood-flow characteristics of the lesions measured using colour Doppler ultrasonography. The characteristics of the haemangiomas in these children were compared with a cohort of untreated cases. Eight of nine treated children were female, this proportion being significantly different from the equal sex distribution of an untreated cohort (p suppression persisting for several months (between 5 and 20) before the lesion later displays the cyclic fluctuations in volume and flow seen with untreated lesions. All treated haemangiomas had some residual vascular anomaly, detectable on ultrasonography, at last follow-up--this being despite absence of clinical signs in most cases. Periorbital capillary haemangiomas requiring steroid therapy for risk of amblyopia were significantly commoner in females, were larger lesions and presented at an earlier age. Intralesional steroids appear to cause a reduction of blood flow, with a transient reduction in volume and a suppression of the natural cyclic variation seen without treatment. The changes after a course of steroid therapy appear to last for between 5 and 20 months, this period of suppression of the lesion probably being particularly useful during infancy and early childhood when the child is at greatest risk of amblyopia.

A simple method to determine the blood volume of newborns with serum-albumin labeled with technetium-99m (HSA-sup(99m)Tc)

International Nuclear Information System (INIS)

Camargo, E.E.; Vaz, F.A.C.; Rockmann, R.L.; Barreto, T.M.; Eston, T.E. de; Carvalho, N.

1973-01-01

A method for determination of small volumes, with which it is determined blood volume of 11 newborns, is described. By injecting through the anterior fontannelle 1 ml a human serum albumin solution labelled with technetium-99m and withdrawing from the posterior fontanelle blood samples of 1.2 to 1.5 ml at 10, 20 and 30 minutes after the injection, the possibility of determining blood volume with only two of these samples without using a standard is shown. Non-significant whole body radiation (3.2 mrad/6h) is shown as well [pt

Irradiation of blood, blood compounds and cell culture in equipment of radiotherapy of clinical usage. Study about volume and ideal dose

International Nuclear Information System (INIS)

Fernandes, Marco Antonio Rodrigues; Pereira, Adelino Jose; Novaes, Paulo Eduardo Ribeiro dos Santos

1996-01-01

The irradiation of blood bags with the objective of minimizing the graft-versus-host disease in the proceedings of blood transfusion has been consolidated as an indispensable step in the advances of hematopoietic system diseases therapeutics. This practice performed in the great oncological treatment centers requires appropriate equipment (cell irradiators), that due to the high coast, is inaccessible to the majority of the services. The main objective of this work is the show the technique developed by the Radiological Physics Service of the Hospital A. C. Camargo Radiation Department, using the teletherapy equipment of clinical usage available at the Institution. The literature shows that a total dose of 2000 to 3500 c Gy must be administered to all target volume to get an ideal dose/volume relation that proportionates better therapeutic results, neutralizing the cells which are causative of post transfusion reactions of rejection, without prejudicing the other cells that are necessary to the maintenance and preservation of the transplanted person's hematopoietic system functions. With the technic developed for optimization of the irradiation. it is possible to conclude that the utilization of radiotherapy equipment of clinical usage for blood irradiation, substituting cells irradiators, is a good option, permitting safe transfusion of products irradiated with adequate dose. (author)

Utility of multiparametric 3-T MRI for glioma characterization

International Nuclear Information System (INIS)

Roy, Bhaswati; Gupta, Rakesh K.; Maudsley, Andrew A.; Sheriff, Sulaiman; Awasthi, Rishi; Mohakud, Sudipta; Gu, Meng; Spielman, Daniel M.; Husain, Nuzhat; Behari, Sanjay; Pandey, Chandra M.; Rathore, Ram K.S.; Alger, Jeffry R.

2013-01-01

Accurate grading of cerebral glioma using conventional structural imaging techniques remains challenging due to the relatively poor sensitivity and specificity of these methods. The purpose of this study was to evaluate the relative sensitivity and specificity of structural magnetic resonance imaging and MR measurements of perfusion, diffusion, and whole-brain spectroscopic parameters for glioma grading. Fifty-six patients with radiologically suspected untreated glioma were studied with T1- and T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, diffusion tensor imaging, and volumetric whole-brain MR spectroscopic imaging. Receiver-operating characteristic analysis was performed using the relative cerebral blood volume (rCBV), apparent diffusion coefficient, fractional anisotropy, and multiple spectroscopic parameters to determine optimum thresholds for tumor grading and to obtain the sensitivity, specificity, and positive and negative predictive values for identifying high-grade gliomas. Logistic regression was performed to analyze all the parameters together. The rCBV individually classified glioma as low and high grade with a sensitivity and specificity of 100 and 88 %, respectively, based on a threshold value of 3.34. On combining all parameters under consideration, the classification was achieved with 2 % error and sensitivity and specificity of 100 and 96 %, respectively. Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters. (orig.)

Detection of Low-volume Blood Loss: Compensatory Reserve Versus Traditional Vital Signs

Science.gov (United States)

2014-01-01

follows: heart rate (HR), blood pressure (BP), respiratory rate, and oxygen saturation. These vital signs are, however, notoriously unreliable.2,3 As...additional tests using specific equipment.22 Base deficit (BD) is a rapidly and widely available serum laboratory marker of systemic acidosis that...and mortality.23,24 BD can increase, however, because of any derangement causing metabolic acidosis and is not limited to intravascular volume loss

Anuran amphibians as comparative models for understanding extreme dehydration tolerance: a negative feedback lymphatic mechanism for blood volume regulation.

Science.gov (United States)

Hillman, Stanley S

2018-06-06

Anurans are the most terrestrial order of amphibians. Couple the high driving forces for evaporative loss in terrestrial environments and their low resistance to evaporation, dehydration is an inevitable stress on their water balance. Anurans have the greatest tolerances for dehydration of any vertebrate group, some species can tolerate evaporative losses up to 45% of their standard body mass. Anurans have remarkable capacities to regulate blood volume with hemorrhage and dehydration compared to mammals. Stabilization of blood volume is central to extending dehydration tolerance, since it avoids both the hypovolemic and hyperviscosity stresses on cardiac output and its consequential effects on aerobic capacity. Anurans, in contrast to mammals, seem incapable of generating a sufficient pressure difference, either oncotically or via interstitial compliance, to move fluid from the interstitium into the capillaries. Couple this inability to generate a sufficient pressure difference for transvascular uptake to a circulatory system with high filtration coefficients and a high rate of plasma turnover is the consequence. The novel lymphatic system of anurans is critical to a remarkable capacity for blood volume regulation. This review summarizes what is known about the anatomical and physiological specializations which are involved in explaining differential blood volume regulation and dehydration tolerance involving a true centrally mediated negative feedback of lymphatic function involving baroreceptors as sensors and lymph hearts, AVT, pulmonary ventilation and specialized skeletal muscles as effectors.

Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: Preliminary report

Energy Technology Data Exchange (ETDEWEB)

Bladowska, Joanna, E-mail: asia.bladowska@gmail.com [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Zimny, Anna, E-mail: abernac@wp.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Guziński, Maciej, E-mail: guziol@wp.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Hałoń, Agnieszka, E-mail: ahalon2@gmail.com [Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Tabakow, Paweł, E-mail: p.tabakov@wp.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Czyż, Marcin, E-mail: mt.czyz@gmail.com [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Czapiga, Bogdan, E-mail: bogdanczapiga@op.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Jarmundowicz, Włodzimierz, E-mail: jarmund@wp.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Sąsiadek, Marek J., E-mail: marek.sasiadek@am.wroc.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland)

2013-08-15

Purpose: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. Methods: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. Results: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p = 0.026 and p = 0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. Conclusions: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors.

Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: Preliminary report

International Nuclear Information System (INIS)

Bladowska, Joanna; Zimny, Anna; Guziński, Maciej; Hałoń, Agnieszka; Tabakow, Paweł; Czyż, Marcin; Czapiga, Bogdan; Jarmundowicz, Włodzimierz; Sąsiadek, Marek J.

2013-01-01

Purpose: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. Methods: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. Results: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p = 0.026 and p = 0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. Conclusions: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors

Multiparametric MR assessment of pediatric brain tumors

International Nuclear Information System (INIS)

Tzika, A.A.; Astrakas, L.G.; Zarifi, M.K.; Petridou, N.; Young-Poussaint, T.; Goumnerova, L.; Black, P.McL.; Zurakowski, D.; Anthony, D.C.

2003-01-01

MR assessment of pediatric brain tumors has expanded to include physiologic information related to cellular metabolites, hemodynamic and diffusion parameters. The purpose of this study was to investigate the relationship between MR and proton MR spectroscopic imaging in children with primary brain tumors. Twenty-one patients (mean age 9 years) with histologically verified brain tumors underwent conventional MR imaging, hemodynamic MR imaging (HMRI) and proton MR spectroscopic imaging (MRSI). Fourteen patients also had diffusion-weighted MR imaging (DWMRI). Metabolic indices including choline-containing compounds (Cho), total creatine (tCr) and lipids/lactate (L) were derived by proton MRSI, relative cerebral blood volume (rCBV) by HMRI, and apparent tissue water diffusion coefficients (ADC) by DWMRI. Variables were examined by linear regression and correlation as well as by ANOVA. Cho (suggestive of tumor cellularity and proliferative activity) correlated positively with rCBV, while the relationship between Cho and ADC (suggestive of cellular density) was inverse (P<0.001). The relationship between rCBV and ADC was also inverse (P=0.004). Cho and lipids (suggestive of necrosis and/or apoptosis) were not significantly correlated (P=0.51). A positive relationship was found between lipids and ADC (P=0.002). The relationships between Cho, rCBV, ADC and lipids signify that tumor physiology is influenced by the tumor's physical and chemical environment. Normalized Cho and lipids distinguished high-grade from low-grade tumors (P<0.05). Multiparametric MR imaging using MRSI, HMRI and DWMRI enhances assessment of brain tumors in children and improves our understanding of tumor physiology while promising to distinguish higher- from lower-malignancy tumors, a distinction that is particularly clinically important among inoperable tumors. (orig.)

Regional blood flow analysis and its relationship with arterial branch lengths and lumen volume in the coronary arterial tree

International Nuclear Information System (INIS)

Molloi, Sabee; Wong, Jerry T

2007-01-01

The limitations of visually assessing coronary artery disease are well known. These limitations are particularly important in intermediate coronary lesions (30-70% diameter stenosis) where it is difficult to determine whether a particular lesion is the cause of ischaemia. Therefore, a functional measure of stenosis severity is needed. The purpose of this study is to determine whether the expected maximum coronary blood flow in an arterial tree is predictable from its sum of arterial branch lengths or lumen volume. Using a computer model of a porcine coronary artery tree, an analysis of blood flow distribution was conducted through a network of millions of vessels that included the entire coronary artery tree down to the first capillary branch. The flow simulation results show that there is a linear relationship between coronary blood flow and the sum of its arterial branch lengths. This relationship holds over the entire arterial tree. The flow simulation results also indicate that there is a 3/4 er relation between coronary blood flow (Q) and the sum of its arterial lumen volume (V). Moreover, there is a linear relationship between normalized Q and normalized V raised to a power of 3/4 over the entire arterial tree. These results indicate that measured arterial branch lengths or lumen volumes can be used to predict the expected maximum blood flow in an arterial tree. This theoretical maximum blood flow, in conjunction with an angiographically measured blood flow, can potentially be used to calculate fractional flow reserve based entirely on angiographic data

Study of cerebral circulation for patients with head injury

International Nuclear Information System (INIS)

Honda, Mitsuru; Aoki, Yoshinori; Noguchi, Yoshitaka; Haga, Daisuke; Seiki, Yoshikatsu; Machida, Keiichi

2004-01-01

Severe traumatic brain injury is widely known to cause a dynamic cerebral blood flow (CBF). Especially, decrease of CBF has been reported. In the present study we measured the CBF, the mean transit time (MTT) and the cerebral blood volume (CBV). Our purpose was to investigate the possibility to estimate the outcome with use of these physiological parameters, and the relationship between the clinical condition of the patients and these parameters. In 24 patients with traumatic brain injury, Xe-CT and Perfusion CT were performed at the same time in the phase II (Day 1-3). We measured CBF by using Xe-CT and MTT by using Perfusion CT and calculated CBV by using AZ-7000W98 computer system. We evaluated the relationship between these values and outcome, grading on admission and discussed the usefulness of deciding on courses of treatment. The results were correlated with the outcome and values of CBF and MTT. Significant differences in CBF and MTT were found between favorable outcome group (good recovery (GR) and moderate disability (MD)) and poor outcome group (severe disability (SD), vegetative state (VS) and dead (D)). We could estimate the outcome of patients with subarachnoid hemorrhage (SAH) by analyzing values of CBF and MTT. The probability was 78%. (authors)

Evaluation of brain perfusion in Alzheimer disease with perfusion computed tomography and comparison to elderly patient without dementia.

Science.gov (United States)

Yildirim, Tülin; Karakurum Göksel, Başak; Demir, Şenay; Tokmak, Naime; Tan, Meliha

2016-04-19

The aim of this study was to evaluate perfusion computed tomography (PCT) findings in patients with Alzheimer disease and to compare them with those of patients without dementia. PCT was performed in 35 patients: 20 with Alzheimer disease (mean age, 69.7 ± 5.5 years) and 15 control subjects (mean age, 67.5 ± 3.5 years). Control subjects were elderly individuals with no cognitive problems who were admitted with headaches. All PCT examinations were performed on a 4-slice CT unit. The PCT analysis software program was used to calculate regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional time-to-peak (rTTP) values in the bilateral frontal, temporal, and occipital cortices, and bilateral lentiform nucleus. rCBF values in the bilateral frontal and temporal cortices and bilateral lentiform nucleus were significantly lower in the patients with Alzheimer disease than in the control subjects. There were no significant differences in rCBV values between Alzheimer disease and the control group. rTTP values in all cortical areas and bilateral lentiform nucleus were significantly higher in the patients with Alzheimer disease than in the control subjects. PCT is a rapid and reliable imaging modality for evaluating brain perfusion in Alzheimer disease.

Nitric oxide, prostaglandins and angiotensin II in the regulation of renal medullary blood flow during volume expansion.

Science.gov (United States)

Moreno, Carol; Llinás, María T; Rodriguez, Francisca; Moreno, Juan M; Salazar, F Javier

2016-03-01

Regulation of medullary blood flow (MBF) is essential in maintaining renal function and blood pressure. However, it is unknown whether outer MBF (OMBF) and papillary blood flow (PBF) are regulated independently when extracellular volume (ECV) is enhanced. The aim of this study was to determine whether OMBF and PBF are differently regulated and whether there is an interaction between nitric oxide (NO), prostaglandins (PGs) and angiotensin II (Ang II) in regulating OMBF and PBF when ECV is enhanced. To achieve these goals, OMBF and PBF were measured by laser-Doppler in volume-expanded rats treated with a cyclooxygenase inhibitor (meclofenamate, 3 mg/kg) and/or a NO synthesis inhibitor (L-nitro-arginine methyl ester (L-NAME), 3 μg/kg/min) and/or Ang II (10 ng/kg/min). OMBF was unchanged by NO or PGs synthesis inhibition but decreased by 36 % (P blood flows to the outer medulla and renal papilla are differently regulated and showing that there is a complex interaction between NO, PGs and Ang II in regulating OMBF and PBF when ECV is enhanced.

Goal-directed fluid therapy: stroke volume optimisation and cardiac dimensions in supine healthy humans

DEFF Research Database (Denmark)

Jans, O.; Tollund, C.; Bundgaard-Nielsen, M.

2008-01-01

BACKGROUND: Based on maximisation of cardiac stroke volume (SV), peri-operative individualised goal-directed fluid therapy improves patient outcome. It remains, however, unknown how fluid therapy by this strategy relates to filling of the heart during supine rest as reference for the anaesthetised...... by thoracic electrical admittance, central venous oxygenation and pressure, and arterial plasma atrial natriuretic peptide. Also, muscle and brain oxygenation were assessed by near infrared spectroscopy (n=7). RESULTS: The HUT reduced the mentioned indices of CBV, the end-diastolic dimensions of the heart...... therapy is that when a maximal SV is established for patients, cardiac pre-load is comparable to that of supine healthy subjects Udgivelsesdato: 2008/4...

Altitude Acclimatization and Blood Volume: Effects of Exogenous Erythrocyte Volume Expansion

National Research Council Canada - National Science Library

Sawka, M

1996-01-01

...: (a) altitude acclimatization effects on erythrocyte volume and plasma volume; (b) if exogenous erythrocyte volume expansion alters subsequent erythrocyte volume and plasma volume adaptations; (c...

Combined value of susceptibility weighted imaging and dynamic susceptibility-weighted contrast-enhanced MR perfusion-weighted imaging in brain astrocytoma grading

International Nuclear Information System (INIS)

Wang Xiaochun; Zhang Hui; Qin Jiangbo; Wang Le; Wu Xiaofeng

2012-01-01

Objective: To assess the value of combination of susceptibility weighted imaging (SWI) and dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion-weighted magnetic resonance imaging in astrocytoma grading. Methods: SWI and DSC scans were performed in 82 patients with pathologically confirmed astrocytoma. The patient group consisted of grade Ⅱ (15), grade Ⅲ (10), and grade Ⅳ (57). The intratumoral susceptibility signal intensity (ITSS) and relative cerebral blood volume (rCBV) max were used to determine the grade of astrocytomas by Kruskal Wallis test, Welch test, Spearman correlation coefficients, Pearson correlation coefficients, and receiver operating characteristic curve (ROC)statistic methods. Results: There were no ITSS in 14 cases of low-grade astrocytomas, the degree of ITSS were grade 1 to 3 in anaplastic astrocytomas, the degree of ITSS were grade 3 in all of the glioblastomas, the degree of ITSS were significant difference in all grades (H=71.96, P<0.01). rCBV max in grade Ⅱ, grade Ⅲ and grade Ⅳ astrocytomas were 1.26 ± 0.42, 3.59 ± 2.09 and 8.34 ± 1.16 respectively, rCBV max were significant difference in all grades (F'=681.72, P<0.01). ITSS showed significant correlation with rCBV max (r=0.72, P<0.01) and tumor grades (r=0.89, P<0.01), and rCBV and tumor grades showed significant correlation (r=0.78, P<0.01). Area under the ROC curve application SWI, DSC, SWI and DSC in differentiation of the grade Ⅱ and grade Ⅲ astrocytomas were 0.99, 0.93, 1.00, differentiate grade Ⅲ from grade Ⅳ were 0.70, 0.94, 0.94, and differentiate high-grade from low-grade astrocytomas were 1.00, 0.99, 1.00. Conclusions: ITSS is helpful to determine the grade of astrocytomas. The use of SWI in combination with DSC may improve the diagnostic accuracy of astrocytoma grading. (authors)

Value of dynamic susceptibility contrast perfusion MRI in the acute phase of transient global amnesia.

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Alex Förster

Full Text Available Transient global amnesia (TGA is a transitory, short-lasting neurological disorder characterized by a sudden onset of antero- and retrograde amnesia. Perfusion abnormalities in TGA have been evaluated mainly by use of positron emission tomography (PET or single-photon emission computed tomography (SPECT. In the present study we explore the value of dynamic susceptibility contrast perfusion-weighted MRI (PWI in TGA in the acute phase.From a MRI report database we identified TGA patients who underwent MRI including PWI in the acute phase and compared these to control subjects. Quantitative perfusion maps (cerebral blood flow (CBF and volume (CBV were generated and analyzed by use of Signal Processing In NMR-Software (SPIN. CBF and CBV values in subcortical brain regions were assessed by use of VOI created in FIRST, a model-based segmentation tool in the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB Software Library (FSL.Five TGA patients were included (2 men, 3 women. On PWI, no relevant perfusion alterations were found by visual inspection in TGA patients. Group comparisons for possible differences between TGA patients and control subjects showed significant lower rCBF values bilaterally in the hippocampus, in the left thalamus and globus pallidus as well as bilaterally in the putamen and the left caudate nucleus. Correspondingly, significant lower rCBV values were observed bilaterally in the hippocampus and the putamen as well as in the left caudate nucleus. Group comparisons for possible side differences in rCBF and rCBV values in TGA patients revealed a significant lower rCBV value in the left caudate nucleus.Mere visual inspection of PWI is not sufficient for the assessment of perfusion changes in TGA in the acute phase. Group comparisons with healthy control subjects might be useful to detect subtle perfusion changes on PWI in TGA patients. However, this should be confirmed in larger data sets and serial PWI

Volume-dependent K+ transport in rabbit red blood cells comparison with oxygenated human SS cells

Energy Technology Data Exchange (ETDEWEB)

Al-Rohil, N.; Jennings, M.L.

1989-07-01

In this study the volume-dependent or N-ethylmaleimide (NEM)-stimulated, ouabain-insensitive K+ influx and efflux were measured with the tracer 86Rb+ in rabbit red blood cells. The purpose of the work was to examine the rabbit as a potential model for cell volume regulation in human SS red blood cells and also to investigate the relationship between the NEM-reactive sulfhydryl group(s) and the signal by which cell swelling activates the transport. Ouabain-resistant K+ efflux and influx increase nearly threefold in cells swollen hypotonically by 15%. Pretreatment with 2 mM NEM stimulates efflux 5-fold and influx 10-fold (each measured in an isotonic medium). The ouabain-resistant K+ efflux was dependent on the major anion in the medium. The anion dependence of K+ efflux in swollen or NEM-stimulated cells was as follows: Br- greater than Cl- much greater than NO3- = acetate. The magnitudes of both the swelling- and the NEM-stimulated fluxes are much higher in young cells (density separated but excluding reticulocytes) than in older cells. Swelling- or NEM-stimulated K+ efflux in rabbit red blood cells was inhibited 50% by 1 mM furosemide, and the inhibitory potency of furosemide was enhanced by extracellular K+, as is known to be true for human AA and low-K+ sheep red blood cells. The swelling-stimulated flux in both rabbit and human SS cells has a pH optimum at approximately 7.4. We conclude that rabbit red blood cells are a good model for swelling-stimulated K+ transport in human SS cells.

Dynamic CT Perfusion Imaging for the Detection of Crossed Cerebellar Diaschisis in Acute Ischemic Stroke

International Nuclear Information System (INIS)

Jeon, Young Wook; Kim, Seo Hyun; Lee, Ji Young; Whang, Kum; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub; Brain Reserch Group

2012-01-01

Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke. CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the toggling-table technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases. The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly (p < 0.05) with each other in CCD-positive cases. It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke.

Interaction between peri-operative blood transfusion, tidal volume, airway pressure and postoperative ARDS: an individual patient data meta-analysis.

Science.gov (United States)

Serpa Neto, Ary; Juffermans, Nicole P; Hemmes, Sabrine N T; Barbas, Carmen S V; Beiderlinden, Martin; Biehl, Michelle; Fernandez-Bustamante, Ana; Futier, Emmanuel; Gajic, Ognjen; Jaber, Samir; Kozian, Alf; Licker, Marc; Lin, Wen-Qian; Memtsoudis, Stavros G; Miranda, Dinis Reis; Moine, Pierre; Paparella, Domenico; Ranieri, Marco; Scavonetto, Federica; Schilling, Thomas; Selmo, Gabriele; Severgnini, Paolo; Sprung, Juraj; Sundar, Sugantha; Talmor, Daniel; Treschan, Tanja; Unzueta, Carmen; Weingarten, Toby N; Wolthuis, Esther K; Wrigge, Hermann; de Abreu, Marcelo Gama; Pelosi, Paolo; Schultz, Marcus J

2018-01-01

Transfusion of blood products and mechanical ventilation with injurious settings are considered risk factors for postoperative lung injury in surgical Patients. A systematic review and individual patient data meta-analysis was done to determine the independent effects of peri-operative transfusion of blood products, intra-operative tidal volume and airway pressure in adult patients undergoing mechanical ventilation for general surgery, as well as their interactions on the occurrence of postoperative acute respiratory distress syndrome (ARDS). Observational studies and randomized trials were identified by a systematic search of MEDLINE, CINAHL, Web of Science, and CENTRAL and screened for inclusion into a meta-analysis. Individual patient data were obtained from the corresponding authors. Patients were stratified according to whether they received transfusion in the peri-operative period [red blood cell concentrates (RBC) and/or fresh frozen plasma (FFP)], tidal volume size [≤7 mL/kg predicted body weight (PBW), 7-10 and >10 mL/kg PBW] and airway pressure level used during surgery (≤15, 15-20 and >20 cmH 2 O). The primary outcome was development of postoperative ARDS. Seventeen investigations were included (3,659 patients). Postoperative ARDS occurred in 40 (7.2%) patients who received at least one blood product compared to 40 patients (2.5%) who did not [adjusted hazard ratio (HR), 2.32; 95% confidence interval (CI), 1.25-4.33; P=0.008]. Incidence of postoperative ARDS was highest in patients ventilated with tidal volumes of >10 mL/kg PBW and having airway pressures of >20 cmH 2 O receiving both RBC and FFP, and lowest in patients ventilated with tidal volume of ≤7 mL/kg PBW and having airway pressures of ≤15 cmH 2 O with no transfusion. There was a significant interaction between transfusion and airway pressure level (P=0.002) on the risk of postoperative ARDS. Peri-operative transfusion of blood products is associated with an increased risk of

Perfusion magnetic resonance imaging and magnetic resonance spectroscopy of cerebral gliomas showing imperceptible contrast enhancement on conventional magnetic resonance imaging

International Nuclear Information System (INIS)

Batra, A.; Tripathi, R.P.; Singh, A.K.

2004-01-01

The purpose of the present paper was to evaluate the utility of perfusion MRI in cerebral gliomas showing imperceptible contrast enhancement on conventional MRI, and to evaluate the relationships of perfusion MRI and magnetic resonance (MR) spectroscopic results in these tumours. Twenty-two patients with histopathologically proven cerebral gliomas and showing insignificant contrast enhancement on conventional MR were included in the present study. All patients underwent perfusion MRI and MR spectroscopy on a 1.5-T MR system. Significant differences of the relative cerebral blood volume (rCBV) values and the choline : creatine ratios were noted between low-grade and anaplastic gliomas (P < 0.01). Good correlation was found between the rCBV values and the choline : creatine values (y = 0. 532x + 1.5643; r = 0.67). Perfusion MRI can be a useful tool in assessing the histopathological grade of non-contrast-enhancing cerebral gliomas. Along with MR spectroscopic imaging it can serve as an important technique for preoperative characterization of such gliomas, so that accurate targeting by stereotactic biopsies is possible. Copyright (2004) Blackwell Science Pty Ltd

Photoplethysmography for blood volumes and oxygenation changes during intermittent vascular occlusions.

Science.gov (United States)

Abay, T Y; Kyriacou, P A

2018-06-01

Photoplethysmography (PPG) is an optical technique that measures blood volume variations. The main application of dual-wavelength PPG is pulse oximetry, in which the arterial oxygen saturation (SpO[Formula: see text]) is calculated noninvasively. However, the PPG waveform contains other significant physiological information that can be used in conjunction to SpO[Formula: see text] for the assessment of oxygenation and blood volumes changes. This paper investigates the use of near infrared spectroscopy (NIRS) processing techniques for extracting relative concentration changes of oxygenated ([Formula: see text]HbO[Formula: see text]), reduced ([Formula: see text]HHb) and total haemoglobin ([Formula: see text]tHb) from dual-wavelength PPG signals during intermittent pressure-increasing vascular occlusions. A reflectance PPG sensor was attached on the left forearm of nineteen (n = 19) volunteers, along with a reference NIRS sensor positioned on the same forearm, above the left brachioradialis. The investigation protocol consisted of seven intermittent and pressure-increasing vascular occlusions. Relative changes in haemoglobin concentrations were obtained by applying the modified Beer-Lambert law to PPG signals, while oxygenation changes were estimated by the difference between red and infrared attenuations of DC PPGs (A[Formula: see text] = [Formula: see text]A[Formula: see text] - [Formula: see text]A[Formula: see text]) and by the conventional SpO[Formula: see text]. The [Formula: see text]HbO[Formula: see text], [Formula: see text]HHb, [Formula: see text]tHb from the PPG signals indicated significant changes in perfusion induced by either partial and complete occlusions (p < 0.05). The trends in the variables extracted from PPG showed good correlation with the same parameters measured by the reference NIRS monitor. Bland and Altman analysis of agreement between PPG and NIRS showed underestimation of the magnitude of changes by the PPG. A[Formula: see text

Impedance cardiography: Pulsatile blood flow and the biophysical and electrodynamic basis for the stroke volume equations

Directory of Open Access Journals (Sweden)

Donald P Bernstein

2010-01-01

Full Text Available Impedance cardiography (ICG is a branch of bioimpedance pimarily concerned with the determination of left ventricular stroke volume (SV. As implemented, using the transthoracic approach, the technique involves applying a current field longitudinally across a segment of thorax by means of a constant magnitude, high frequency, low amplitude alternating current (AC. By Ohm's Law, the voltage difference measured within the current field is proportional to the electrical impedance Z (Ω. Without ventilatory or cardiac activity, Z is known as the transthoracic, static base impedance Z0. Upon ventricular ejection, a characteristic time dependent cardiac-synchronous pulsatile impedance change is obtained, ΔZ(t, which, when placed electrically in parallel with Z0, constitutes the time-variable total transthoracic impedance Z(t. ΔZ(t represents a dual-element composite waveform, which comprises both the radially-oriented volumetric expansion of and axially-directed forward blood flow within both great thoracic arteries. In its majority, however, ΔZ(t is known to primarily emanate from the ascending aorta. Conceptually, commonly implemented methods assume a volumetric origin for the peak systolic upslope of ΔZ(t, (i.e. dZ/dtmax, with the presumed units of Ω·s-1. A recently introduced method assumes the rapid ejection of forward flowing blood in earliest systole causes significant changes in the velocity-induced blood resistivity variation (Δρb(t, Ωcm·s-1, and it is the peak rate of change of the blood resistivity variation dρb(t/dtmax (Ωcm·s-2 that is the origin of dZ/dtmax. As a consequence of dZ/dtmax peaking in the time domain of peak aortic blood acceleration, dv/dtmax (cm·s-2, it is suggested that dZ/dtmax is an ohmic mean acceleration analog (Ω·s-2 and not a mean flow or velocity surrogate as generally assumed. As conceptualized, the normalized value, dZ/dtmax/Z0, is a dimensionless ohmic mean acceleration equivalent (s-2

Estimation of prognosis for severe subarachnoid hemorrhage by initial CT perfusion

International Nuclear Information System (INIS)

Fukumitsu, Ryu; Yoshida, Kazumichi; Yamamoto, Hiroyuki

2009-01-01

While poor-grade subarachnoid hemorrhage (SAH) is generally associated with high mortality and morbidity, some patients make an unexpected dramatic recovery. To estimate prognosis for severe SAH, we assessed cerebral blood circulation by computed tomography perfusion (CTP) imaging on admission. CTP studies were performed for 25 of 49 SAH patients with World Federation of Neurosurgical Societies (WFNS) Grade V between March 2006 and July 2008. Four patients were excluded due to rerupture of aneurysm after CTP images were obtained. We measured cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the cerebral cortex or basal ganglia. Outcomes were assessed using the modified Rankin Scale (mRS), and patients were classified into 3 groups (n=7 each): Group A, mRS 0-3; Group B, mRS 4, 5; and Group C, mRS 6. All patients of Groups A and B underwent surgery, while 6 patients in Group C with mydriasis on admission were treated conservatively. CBF of the cerebral cortex was significantly lower in Group C than in Groups A or B. No significant differences were seen in CBV among the 3 groups. MTTs of cerebral cortex were significantly longer in Group C than in Groups A or B, with a cutoff value of 6.6 s. CTP is a potential modality for poor-grade SAH, in that discrimination between 'false' and 'true' Grade V patients could be made rapidly and less invasively. (author)

Comparison of pathogen DNA isolation methods from large volumes of whole blood to improve molecular diagnosis of bloodstream infections.

Directory of Open Access Journals (Sweden)

Anne J M Loonen

Full Text Available For patients suffering from bloodstream infections (BSI molecular diagnostics from whole blood holds promise to provide fast and adequate treatment. However, this approach is hampered by the need of large blood volumes. Three methods for pathogen DNA isolation from whole blood were compared, i.e. an enzymatic method (MolYsis, 1-5 ml, the novel non-enzymatic procedure (Polaris, 1-5 ml, and a method that does not entail removal of human DNA (Triton-Tris-EDTA EasyMAG, 200 µl. These methods were evaluated by processing blood spiked with 0-1000 CFU/ml of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Downstream detection was performed with real-time PCR assays. Polaris and MolYsis processing followed by real-time PCRs enabled pathogen detection at clinically relevant concentrations of 1-10 CFU/ml blood. By increasing sample volumes, concurrent lower cycle threshold (Ct values were obtained at clinically relevant pathogen concentrations, demonstrating the benefit of using larger blood volumes. A 100% detection rate at a concentration of 10 CFU/ml for all tested pathogens was obtained with the Polaris enrichment, whereas comparatively lower detection rates were measured for MolYsis (50-67% and EasyMAG (58-79%. For the samples with a concentration of 1 CFU/ml Polaris resulted in most optimal detection rates of 70-75% (MolYsis 17-50% and TTE-EasyMAG 20-36%. The Polaris method was more reproducible, less labour intensive, and faster (45 minutes (including Qiagen DNA extraction vs. 2 hours (MolYsis. In conclusion, Polaris and MolYsis enrichment followed by DNA isolation and real-time PCR enables reliable and sensitive detection of bacteria and fungi from 5 ml blood. With Polaris results are available within 3 hours, showing potential for improved BSI diagnostics.

Differentiation of solitary brain metastasis from glioblastoma multiforme: a predictive multiparametric approach using combined MR diffusion and perfusion

Energy Technology Data Exchange (ETDEWEB)

Bauer, Adam Herman; Moser, Franklin G.; Maya, Marcel [Cedars-Sinai Medical Center, Department of Medical Imaging, Los Angeles, CA (United States); Erly, William; Nael, Kambiz [University of Arizona Medical Center, Department of Medical Imaging, Tucson, AZ (United States)

2015-07-15

Solitary brain metastasis (MET) and glioblastoma multiforme (GBM) can appear similar on conventional MRI. The purpose of this study was to identify magnetic resonance (MR) perfusion and diffusion-weighted biomarkers that can differentiate MET from GBM. In this retrospective study, patients were included if they met the following criteria: underwent resection of a solitary enhancing brain tumor and had preoperative 3.0 T MRI encompassing diffusion tensor imaging (DTI), dynamic contrast-enhanced (DCE), and dynamic susceptibility contrast (DSC) perfusion. Using co-registered images, voxel-based fractional anisotropy (FA), mean diffusivity (MD), K{sup trans}, and relative cerebral blood volume (rCBV) values were obtained in the enhancing tumor and non-enhancing peritumoral T2 hyperintense region (NET2). Data were analyzed by logistic regression and analysis of variance. Receiver operating characteristic (ROC) analysis was performed to determine the optimal parameter/s and threshold for predicting of GBM vs. MET. Twenty-three patients (14 M, age 32-78 years old) met our inclusion criteria. Pathology revealed 13 GBMs and 10 METs. In the enhancing tumor, rCBV, K{sup trans}, and FA were higher in GBM, whereas MD was lower, neither without statistical significance. In the NET2, rCBV was significantly higher (p = 0.05) in GBM, but MD was significantly lower (p < 0.01) in GBM. FA and K{sup trans} were higher in GBM, though not reaching significance. The best discriminative power was obtained in NET2 from a combination of rCBV, FA, and MD, resulting in an area under the curve (AUC) of 0.98. The combination of MR diffusion and perfusion matrices in NET2 can help differentiate GBM over solitary MET with diagnostic accuracy of 98 %. (orig.)

Differentiation of solitary brain metastasis from glioblastoma multiforme: a predictive multiparametric approach using combined MR diffusion and perfusion

International Nuclear Information System (INIS)

Bauer, Adam Herman; Moser, Franklin G.; Maya, Marcel; Erly, William; Nael, Kambiz

2015-01-01

Solitary brain metastasis (MET) and glioblastoma multiforme (GBM) can appear similar on conventional MRI. The purpose of this study was to identify magnetic resonance (MR) perfusion and diffusion-weighted biomarkers that can differentiate MET from GBM. In this retrospective study, patients were included if they met the following criteria: underwent resection of a solitary enhancing brain tumor and had preoperative 3.0 T MRI encompassing diffusion tensor imaging (DTI), dynamic contrast-enhanced (DCE), and dynamic susceptibility contrast (DSC) perfusion. Using co-registered images, voxel-based fractional anisotropy (FA), mean diffusivity (MD), K trans , and relative cerebral blood volume (rCBV) values were obtained in the enhancing tumor and non-enhancing peritumoral T2 hyperintense region (NET2). Data were analyzed by logistic regression and analysis of variance. Receiver operating characteristic (ROC) analysis was performed to determine the optimal parameter/s and threshold for predicting of GBM vs. MET. Twenty-three patients (14 M, age 32-78 years old) met our inclusion criteria. Pathology revealed 13 GBMs and 10 METs. In the enhancing tumor, rCBV, K trans , and FA were higher in GBM, whereas MD was lower, neither without statistical significance. In the NET2, rCBV was significantly higher (p = 0.05) in GBM, but MD was significantly lower (p < 0.01) in GBM. FA and K trans were higher in GBM, though not reaching significance. The best discriminative power was obtained in NET2 from a combination of rCBV, FA, and MD, resulting in an area under the curve (AUC) of 0.98. The combination of MR diffusion and perfusion matrices in NET2 can help differentiate GBM over solitary MET with diagnostic accuracy of 98 %. (orig.)

Activity restriction, impaired capillary function, and the development of insulin resistance in lean primates.

Science.gov (United States)

Chadderdon, Scott M; Belcik, J Todd; Smith, Elise; Pranger, Lindsay; Kievit, Paul; Grove, Kevin L; Lindner, Jonathan R

2012-09-01

Insulin produces capillary recruitment in skeletal muscle through a nitric oxide (NO)-dependent mechanism. Capillary recruitment is blunted in obese and diabetic subjects and contributes to impaired glucose uptake. This study's objective was to define whether inactivity, in the absence of obesity, leads to impaired capillary recruitment and contributes to insulin resistance (IR). A comprehensive metabolic and vascular assessment was performed on 19 adult male rhesus macaques (Macaca mulatta) after sedation with ketamine and during maintenance anesthesia with isoflurane. Thirteen normal-activity (NA) and six activity-restricted (AR) primates underwent contrast-enhanced ultrasound to determine skeletal muscle capillary blood volume (CBV) during an intravenous glucose tolerance test (IVGTT) and during contractile exercise. NO bioactivity was assessed by flow-mediated vasodilation. Although there were no differences in weight, basal glucose, basal insulin, or truncal fat, AR primates were insulin resistant compared with NA primates during an IVGTT (2,225 ± 734 vs. 5,171 ± 3,431 μg·ml⁻¹·min⁻¹, P < 0.05). Peak CBV was lower in AR compared with NA primates during IVGTT (0.06 ± 0.01 vs. 0.12 ± 0.02 ml/g, P < 0.01) and exercise (0.10 ± 0.02 vs. 0.20 ± 0.02 ml/g, P < 0.01), resulting in a lower peak skeletal muscle blood flow in both circumstances. The insulin-mediated changes in CBV correlated inversely with the degree of IR and directly with activity. Flow-mediated dilation was lower in the AR primates (4.6 ± 1.0 vs. 9.8 ± 2.3%, P = 0.01). Thus, activity restriction produces impaired skeletal muscle capillary recruitment during a carbohydrate challenge and contributes to IR in the absence of obesity. Reduced NO bioactivity may be a pathological link between inactivity and impaired capillary function.

Evaluation of regional cerebral circulation and metabolism in moyamoya disease using positron emission computed tomography

International Nuclear Information System (INIS)

Kuwabara, Yasuo

1986-01-01

Regional cerebral blood flow, oxygen extraction fraction, metabolic rate of oxygen, blood volume and transit time were evaluated in 11 patients with moyamoya disease and 3 with suspected moyamoya disease using positron emission computed tomography. Eight of them were examined before and after EC-IC bypass surgery. Moyamoya patients were classified into four groups, namely, pediatric bilateral chronic type (over 5 years from onset), pediatric bilateral early type (within 5 years from onset), pediatric unilateral early type and adult type, according to age, duration of disease from onset and angiographic findings. These four groups showed different patterns on PET images; diffusely decreased CBF and CMRO2 in pediatric bilateral chronic type, decreased CBF and increased OEF in the frontal or temporoparietal region in pediatric bilateral early type, diffusely decreased CBF and increased OEF in the unilateral cerebral hemisphere in pediatric unilateral cerebral hemisphere in pediatric unilateral early type, and decreased CBF and CMRO2 in adult type. An increase of rCBV was demonstrated in frontal regions or basal ganglia in all groups, more prominently in pediatric patients. This was thought to be a common finding in moyamoya disease, corresponding to moyamoya vessels. Staging of moyamoya disease by PET was presented and compared to the angiographic staging. They were significantly correlated, and the stage 3 on PET image with decreased CMRO2 corresponded to the stage 3 or 4 on angiography, the most active stage of moyamoya disease. PET revealed increased CBF in the cortical area around EC-IC bypass but no remarkable changes in mean values of rCBF, OEF, CMRO2 and CBV in cerebral hemisphere. Some patients showed decreased rCBV in the basal ganglia. (J.P.N.)

Using CT perfusion during the early baseline period in aneurysmal subarachnoid hemorrhage to assess for development of vasospasm

International Nuclear Information System (INIS)

Sanelli, Pina C.; Jou, Austin; Reichman, Melissa; Greenberg, Edward; Cayci, Zuzan; Gold, Rachel; John, Majnu; Ugorec, Igor; Rosengart, Axel

2011-01-01

The aim of this study is to evaluate computed tomography perfusion (CTP) during admission baseline period (days 0-3) in aneurysmal subarachnoid hemorrhage (A-SAH) for development of vasospasm. Retrospective analysis was performed on A-SAH patients from Dec 2004 to Feb 2007 with CTP on days 0-3. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were analyzed for qualitative perfusion deficits. Quantitative analysis was performed using region-of-interest placement to obtain mean CTP values. Development of vasospasm was determined by a multistage hierarchical reference standard incorporating both imaging and clinical criteria. Student's t test and threshold analysis were performed. Seventy-five patients were included, 37% (28/75) were classified as vasospasm. Mean CTP values in vasospasm compared to no vasospasm groups were: CBF 31.90 ml/100 g/min vs. 39.88 ml/100 g/min (P < 0.05), MTT 7.12 s vs. 5.03 s (P < 0.01), and CBV 1.86 ml/100 g vs. 2.02 ml/100 g (P = 0.058). Fifteen patients had qualitative perfusion deficits with 73% (11/15) developed vasospasm. Optimal threshold for CBF is 24-25 mL/100 g/min with 91% specificity and 50% sensitivity, MTT is 5.5 s with 70% specificity and 61% sensitivity and CBV is 1.7 mL/100 g with 89% specificity and 36% sensitivity. These initial results support our hypothesis that A-SAH patients who develop vasospasm may demonstrate early alterations in cerebral perfusion, with statistically significant CBF reduction and MTT prolongation. Overall, CTP has high specificity for development of vasospasm. Future clinical implications include using CTP during the baseline period for early identification of A-SAH patients at high risk for vasospasm to prompt robust preventative measures and treatment. (orig.)

Dysembryoplastic neuroepithelial tumors: proton MR spectroscopy, diffusion and perfusion characteristics

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Bulakbasi, Nail; Kocaoglu, Murat; Sanal, Tuba H.; Tayfun, Cem [Gulhane Military Medical Academy, Department of Radiology, Military Medical Faculty, Ankara (Turkey)

2007-10-15

We describe the magnetic resonance (MR) imaging characteristics of dysembryoplastic neuroepithelial tumors (DNT) and discuss their differential diagnosis. Proton MR spectroscopy (TE 30 and 136 ms), diffusion-weighted and perfusion images were retrospectively evaluated in 22 patients with pathologically proven DNT (17 male and 5 female, mean age 18.7 years) and 14 control subjects (10 male and 4 female, mean age 16.9 years). The results from the DNT patients and from the control subjects were compared using an independent sample t-test and the degree of correlation was tested by Pearson's correlation. All DNTs were solitary and in a supratentorial cortical or subcortical location (ten temporal, eight frontal and four parietal). They had low-signal on T1-weighted images and high-signal on T2-weighted images without a prominent mass effect. Additionally a cystic appearance (six patients, 27.3%), cortical dysplasia (six patients, 27.3%) and contrast enhancement (four patients, 18.2%) were also noted. No significant differences were detected in NAA/Cho, NAA/Cr, NAA/Cho+Cr or Cho/Cr ratios between DNT and normal brain. DNTs had a significantly higher mI/Cr ratio and apparent diffusion coefficient (ADC) values and lower cerebral blood values than normal parenchyma (P < 0.001). ADC had the highest correlation with the diagnosis of DNT (r = 0.996) followed by relative cerebral blood volume (rCBV) (r = -0.883) and mI/Cr ratio (r = 0.663). Proton MR spectroscopy, diffusion-weighted and perfusion imaging characteristics of DNTs provide additional information to their MR imaging findings. The MR spectrum showing a slight increase in mI/Cr ratio, and higher ADC and lower rCBV values than normal parenchyma help to differentiate DNTs from other cortical tumors, which had higher rCBV and lower ADC values than DNTs. (orig.)

Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

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Giuseppe Lippi

2014-01-01

Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

High "normal" blood glucose is associated with decreased brain volume and cognitive performance in the 60s: the PATH through life study.

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Moyra E Mortby

Full Text Available Type 2 diabetes is associated with cerebral atrophy, cognitive impairment and dementia. We recently showed higher glucose levels in the normal range not to be free of adverse effects and to be associated with greater hippocampal and amygdalar atrophy in older community-dwelling individuals free of diabetes.This study aimed to determine whether blood glucose levels in the normal range (<6.1 mmol/L were associated with cerebral volumes in structures other than the hippocampus and amygdale, and whether these glucose-related regional volumes were associated with cognitive performance.210 cognitively healthy individuals (68-73 years without diabetes, glucose intolerance or metabolic syndrome were assessed in the large, community-based Personality and Total Health Through Life (PATH study.Baseline blood glucose levels in the normal range (3.2-6.1 mmol/l were used to determine regional brain volumes and associated cognitive function at wave 3.Higher blood glucose levels in the normal range were associated with lower grey/white matter regional volumes in the frontal cortices (middle frontal gyrus, inferior frontal gyrus precentral gyrus. Moreover, identified cerebral regions were associated with poorer cognitive performance and the structure-function associations were gender specific to men.These findings stress the need to re-evaluate what is considered as healthy blood glucose levels, and consider the role of higher normal blood glucose as a risk factor for cerebral health, cognitive function and dementia. A better lifetime management of blood glucose levels may contribute to improved cerebral and cognitive health in later life and possibly protect against dementia.

Added value of amide proton transfer imaging to conventional and perfusion MR imaging for evaluating the treatment response of newly diagnosed glioblastoma

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Park, Kye Jin; Kim, Ho Sung; Park, Ji Eun; Shim, Woo Hyun; Kim, Sang Joon [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Smith, Seth A. [Vanderbilt University Institute of Imaging Science, Vanderbilt University, Department of Radiology and Radiological Sciences, Nashville, TN (United States)

2016-12-15

To determine the added value of amide proton transfer (APT) imaging to conventional and perfusion MRI for differentiating tumour progression (TP) from the treatment-related effect (TE) in patients with post-treatment glioblastomas. Sixty-five consecutive patients with enlarging contrast-enhancing lesions following concurrent chemoradiotherapy were assessed using contrast-enhanced T1-weighted MRI (CE-T1WI), 90th percentile histogram parameters of normalized cerebral blood volume (nCBV90) and APT asymmetry value (APT90). Diagnostic performance was determined using the area under the receiver operating characteristic curve (AUC) and cross validations. There were statistically significant differences in the mean APT90 between the TP and the TE groups (3.87-4.01 % vs. 1.38-1.41 %; P <.001). Compared with CE-T1WI alone, the addition of APT90 to CE-T1WI significantly improved cross-validated AUC from 0.58-0.74 to 0.89-0.91 for differentiating TP from TE. The combination of CE-T1WI, nCBV90 and APT90 resulted in greater diagnostic accuracy for differentiating TP from TE than the combination of CE-T1WI and nCBV90 (cross-validated AUC, 0.95-0.97 vs. 0.84-0.91). The inter-reader agreement between the expert and trainee was excellent for the measurements of APT90 (intraclass correlation coefficient, 0.94). Adding APT imaging to conventional and perfusion MRI improves the diagnostic performance for differentiating TP from TE. (orig.)

Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

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Arheden Håkan

2011-04-01

Full Text Available Abstract Background Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Methods Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Results Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Conclusion Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking

Volume Tracking: A new method for quantitative assessment and visualization of intracardiac blood flow from three-dimensional, time-resolved, three-component magnetic resonance velocity mapping

International Nuclear Information System (INIS)

Töger, Johannes; Carlsson, Marcus; Söderlind, Gustaf; Arheden, Håkan; Heiberg, Einar

2011-01-01

Functional and morphological changes of the heart influence blood flow patterns. Therefore, flow patterns may carry diagnostic and prognostic information. Three-dimensional, time-resolved, three-directional phase contrast cardiovascular magnetic resonance (4D PC-CMR) can image flow patterns with unique detail, and using new flow visualization methods may lead to new insights. The aim of this study is to present and validate a novel visualization method with a quantitative potential for blood flow from 4D PC-CMR, called Volume Tracking, and investigate if Volume Tracking complements particle tracing, the most common visualization method used today. Eight healthy volunteers and one patient with a large apical left ventricular aneurysm underwent 4D PC-CMR flow imaging of the whole heart. Volume Tracking and particle tracing visualizations were compared visually side-by-side in a visualization software package. To validate Volume Tracking, the number of particle traces that agreed with the Volume Tracking visualizations was counted and expressed as a percentage of total released particles in mid-diastole and end-diastole respectively. Two independent observers described blood flow patterns in the left ventricle using Volume Tracking visualizations. Volume Tracking was feasible in all eight healthy volunteers and in the patient. Visually, Volume Tracking and particle tracing are complementary methods, showing different aspects of the flow. When validated against particle tracing, on average 90.5% and 87.8% of the particles agreed with the Volume Tracking surface in mid-diastole and end-diastole respectively. Inflow patterns in the left ventricle varied between the subjects, with excellent agreement between observers. The left ventricular inflow pattern in the patient differed from the healthy subjects. Volume Tracking is a new visualization method for blood flow measured by 4D PC-CMR. Volume Tracking complements and provides incremental information compared to particle

Volume-activated trimethylamine oxide efflux in red blood cells of spiny dogfish (Squalus acanthias).

Science.gov (United States)

Koomoa, D L; Musch, M W; MacLean, A V; Goldstein, L

2001-09-01

The aims of this study were to determine the pathway of swelling-activated trimethylamine oxide (TMAO) efflux and its regulation in spiny dogfish (Squalus acanthias) red blood cells and compare the characteristics of this efflux pathway with the volume-activated osmolyte (taurine) channel present in erythrocytes of fishes. The characteristics of the TMAO efflux pathway were similar to those of the taurine efflux pathway. The swelling-activated effluxes of both TMAO and taurine were significantly inhibited by known anion transport inhibitors (DIDS and niflumic acid) and by the general channel inhibitor quinine. Volume expansion by hypotonicity, ethylene glycol, and diethyl urea activated both TMAO and taurine effluxes similarly. Volume expansion by hypotonicity, ethylene glycol, and diethyl urea also stimulated the activity of tyrosine kinases p72syk and p56lyn, although the stimulations by the latter two treatments were less than by hypotonicity. The volume activations of both TMAO and taurine effluxes were inhibited by tyrosine kinase inhibitors, suggesting that activation of tyrosine kinases may play a role in activating the osmolyte effluxes. These results indicate that the volume-activated TMAO efflux occurs via the organic osmolyte (taurine) channel and may be regulated by the volume activation of tyrosine kinases.

CT perfusion mapping of hemodynamic disturbances associated to acute spontaneous intracerebral hemorrhage

International Nuclear Information System (INIS)

Fainardi, Enrico; Borrelli, Massimo; Saletti, Andrea; Ceruti, Stefano; Tamarozzi, Riccardo; Schivalocchi, Roberta; Cavallo, Michele; Azzini, Cristiano; Chieregato, Arturo

2008-01-01

We sought to quantify perfusion changes associated to acute spontaneous intracerebral hemorrhage (SICH) by means of computed tomography perfusion (CTP) imaging. We studied 89 patients with supratentorial SICH at admission CT by using CTP scanning obtained within 24 h after symptom onset. Regional cerebral blood flow (rCBF), cerebral blood volume (rCBV) and mean transit time (rMTT) levels were measured in four different regions of interest manually outlined on CT scan: (1) hemorrhagic core; (2) perihematomal low-density area; (3) 1 cm rim of normal-appearing brain tissue surrounding the perilesional area; and (4) a mirrored area, including the clot and the perihematomal region, located in the non-lesioned contralateral hemisphere. rCBF, rCBV, and rMTT mean levels showed a centrifugal distribution with a gradual increase from the core to the periphery (p 20 ml) hematomas (p<0.01 and p <0.02, respectively). Multi-parametric CTP mapping of acute SICH indicates that perfusion values show a progressive improvement from the core to the periphery. In the first 24 h, perihemorrhagic region was hypoperfused with CTP values which were not suggestive of ischemic penumbra destined to survive but more likely indicative of edema formation. These findings also argue for a potential influence of early amounts of bleeding on perihematomal hemodynamic abnormalities. (orig.)

Low dose CT perfusion in acute ischemic stroke.

Science.gov (United States)

Murphy, Amanda; So, Aaron; Lee, Ting-Yim; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I

2014-12-01

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). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54% male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p test post hoc analysis (p 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements.

[Internal quality control of the blood products in the Lomé National Blood Transfusion Centre].

Science.gov (United States)

Fétéké, L; Mawussi, K; Lakté, P; Kuéviakoe, I M; Haudrechy, D; Ségbéna, A Y

2008-07-01

Evaluate the conformity of blood red cells units prepared in the Lomé CNTS with European norms concerning volume, haemoglobin content and haematocrite. Measure the conservation of the haemostatic properties and the rate of haemostasis factors V and VIII in the fresh frozen plasma. Measure the rate of residual cells in the plasma. In the year 2006, from March 1st to April 15th, we analysed the quality of 135 units of whole blood, red blood cells (RBC) and plasma from blood donors in the Lomé National Blood Transfusion Centre. The quality control had concerned: the volume of whole blood units; the volume, the haemoglobin content and the haematocrite of red blood cells units; the volume, the prothrombin rate, the cephalin with activator time (TCA), the rate of haemostasis factors V and VIII and the number of residual cells (red cells, leucocytes and platelets) in the plasma. Among the 135 units of whole blood which were controlled, 50.57% were in conformity with the norms concerning the volume. The red blood cells units were in conformity with norms concerning their volume, their haemoglobin content and their haematocrite respectively in 21.48%, 80.75% and 20% of the cases. The volume of 75.56% of the plasma units controlled were conform with the norm. All of the plasma units were conform with the norm concerning the number of residual platelets while the number of residual red blood cells and leucocytes were conform respectively in 80.74% and 60%. The percentage of conformity concerning the prothrombin rate, the TCA, the coagulation factor V and the factor VIII were respectively 66.67; 97.78; 48.89 and 47.4 before freezing, and 54.81; 88.14; 64.44; 84.44 a month after freezing. To improve the quality of the new blood products of the Lomé CNTS, some correctives actions must be applied concerning the adequate volume of blood which must be collected from the donors, the position of the blood bags in during the centrifugation and the volume of plasma which must be

Volume perfusion CT (VPCT) for the differential diagnosis of patients with suspected cerebral vasospasm: Qualitative and quantitative analysis of 3D parameter maps

International Nuclear Information System (INIS)

Dolatowski, K.; Malinova, V.; Frölich, A.M.J.; Schramm, R.; Haberland, U.; Klotz, E.; Mielke, D.; Knauth, M.; Schramm, P.

2014-01-01

Object: Cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH) implies high risk for secondary ischemia. It requires early diagnosis to start treatment on time. We aimed to assess the utility of “whole brain” VPCT for detecting localization and characteristics of arterial vasospasm. Methods: 23 patients received a non-enhanced CT, VPCT and CTA of the brain. The distribution of ischemic lesions was analyzed on 3D-perfusion-parameter-maps of CBF, CBV, MTT, TTS, TTP, and TTD. CT-angiographic axial and coronal maximum-intensity-projections were reconstructed to determine arterial vasospasm. CT-data was compared to DSA, if performed additionally. Volume-of-interest placement was used to obtain quantitative mean VPCT values. Results: 82% patients (n = 19) had focal cerebral hypoperfusion. 100% sensitivity and 100% specificity was found for TTS (median 1.9 s), MTT (median 5.9 s) and TTD (median 7.6 s). CBV showed no significant differences. In 78% (n = 18) focal vessel aberrations could be detected either on CTA or DSA or on both. Conclusion: VPCT is a non-invasive method with the ability to detect focal perfusion deficits almost in the whole brain. While DSA remains to be the gold standard for detection of CV, VPCT has the potential to improve noninvasive diagnosis and treatment decisions

Effect of hysteroscopic adhesiolysis combined with growth hormone on endometrial blood flow and volume as well as Smad2/3 expression

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Xing-Chan Li

2016-10-01

Full Text Available Objective: To study the effect of hysteroscopic adhesiolysis combined with growth hormone on endometrial blood flow and volume as well as Smad2/3 expression. Methods: A total of 64 patients with moderate or severe intrauterine adhesions who received hysteroscopic adhesiolysis in our hospital from May 2013 to October 2015 were selected as the research subjects and randomly divided into two groups who received different postoperative drug treatment, observation group received postoperative manual cycle intervention combined with growth hormone treatment and control group only received manual cycle intervention. Transvaginal ultrasonography was conducted after treatment to assess endometrial thickness, volume and blood flow, and endometrium was collected to determine Smad2, Smad3 and TGF- β1 levels. Results: After treatment, endometrial blood flow signal of observation group was more abundant than that of control group, ultrasound parameters RI and PI were significantly lower than those of control group, and VI, FI and VFI as well as endometrial thickness and endometrial cavity volume were significantly higher than those of control group; Smad2, Smad3 and TGF-β1 levels in endometrial tissue of observation group after treatment were significantly lower than those of control group. Conclusions: Hysteroscopic adhesiolysis combined with growth hormone therapy can promote endometrial repair and growth, increase endometrial blood flow and volume and also suppress the expression of Smad2/3 and TGF-β1 in patients with intrauterine adhesions.

System modeling and identification in indicator dilution method for assessment of ejection fraction and pulmonary blood volume

NARCIS (Netherlands)

Bharath, H.N.; Prabhu, K.M.M.; Korsten, H.H.M.; Mischi, M.

2012-01-01

Clinically relevant cardiovascular parameters, such as pulmonary blood volume (PBV) and ejection fraction (EF), can be assessed through indicator dilution techniques. Among these techniques, which are typically invasive due to the need for central catheterization, contrast ultrasonography provides a

The anterior cerebral artery is an appropriate arterial input function for perfusion-CT processing in patients with acute stroke

International Nuclear Information System (INIS)

Wintermark, Max; Lau, Benison C.; Chien, Jeffrey; Arora, Sandeep

2008-01-01

Dynamic perfusion-CT (PCT) with deconvolution requires an arterial input function (AIF) for postprocessing. In clinical settings, the anterior cerebral artery (ACA) is often chosen for simplicity. The goals of this study were to determine how the AIF selection influences PCT results in acute stroke patients and whether the ACA is an appropriate default AIF. We retrospectively identified consecutive patients suspected of hemispheric stroke of less than 48 h duration who were evaluated on admission by PCT. PCT datasets were postprocessed using multiple AIF, and cerebral blood volume (CBV) and flow (CBF), and mean transit time (MTT) values were measured in the corresponding territories. Results from corresponding territories in the same patients were compared using paired t-tests. The volumes of infarct core and tissue at risk obtained with different AIFs were compared to the final infarct volume. Of 113 patients who met the inclusion criteria, 55 with stroke were considered for analysis. The MTT values obtained with an ''ischemic'' AIF tended to be shorter (P=0.055) and the CBF values higher (P=0.108) than those obtained using a ''nonischemic'' AIF. CBV values were not influenced by the selection of the AIF. No statistically significant difference was observed between the size of the PCT infarct core (P=0.121) and tissue at risk (P=0.178), regardless of AIF selection. In acute stroke patients, the selection of the AIF has no statistically significant impact of the PCT results; standardization of the PCT postprocessing using the ACA as the default AIF is adequate. (orig.)

Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

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Mark A Lum

Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA and intravenous (IV T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA dural, internal carotid artery (ICA dural, or pial. MR perfusion data regions of interest (ROIs were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM, relative cerebral blood flow (rCBF, relative cerebral blood volume (rCBV, and mean transit time (MTT. Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling.18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11, ICA dural (n = 4, or pial (n = 3. FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

Functional response of tumor vasculature in rats' glioma to hypercarbia evaluated by MR perfusion weighted imaging

International Nuclear Information System (INIS)

Zhang Qingbo; Feng Xiaoyuan; Liang Zonghui; Chen Shuan

2008-01-01

Objective: To evaluate the feasibility of MR PWI in judging maturity and variability of tumor vasculature in gliomas in rats. Methods: Twenty male SD rats were randomly assigned to tumor group and control group. Four weeks after implantation of C6 glioma cells in the brains of tumor group and injection of saline in the brains of control group, all rats were examined using MR PWI before and after inhalation of a mixture of 10% CO2 and 90% air. PaCO 2 and blood pH values of rats were monitored. Relative cerebral blood volume (rCBV) and relative cerebral blood flow(rCBF) values of tumors and normal brain tissue were measured. Brain sample were examined histologically using HE and immunohistochemical staining for smooth muscle actin(SMA). The histological features of gliomas were observed and SMA positively stained vessels of each tumor were counted manually using a light microscope. Perfusion data and pathological findings were analyzed statistically with SPSS for Windows. Results: PaCO 2 increased significantly [from(4.69±0.62)kPa to (7.62±0.81) kPa in tumor group and from (4.67±0.51) kPa to (7.63±0.78) kPa in control group, P 0.05), while changing rate of rCBV, rCBF in normal brain tissue correlated well with number of positive SMA labeled vessels (r=0.721 and 0.525, P 2 increase in the normal brain and in the tumor. It may be a useful technique to measure maturity of tumor vessels. (authors)

Cardiac variation of inferior vena cava: new concept in the evaluation of intravascular blood volume.

Science.gov (United States)

Nakamura, Kensuke; Tomida, Makoto; Ando, Takehiro; Sen, Kon; Inokuchi, Ryota; Kobayashi, Etsuko; Nakajima, Susumu; Sakuma, Ichiro; Yahagi, Naoki

2013-07-01

Evaluation of the intravascular blood volume is an important assessment in emergency and critical care medicine. Measurement of the inferior vena cava (IVC) respiratory variation by ultrasound echography is useful, but it entails subjective problems. We have hypothesized that IVC cardiac variation is also correlated with intravascular blood volume and analyzed it automatically using computer software of two kinds, later comparing the results. Snakes, software to track boundaries by curve line continuity, and template matching software were incorporated into a computer with an ultrasound machine to track the short-axis view of IVC automatically and analyze it with approximation by ellipse. Eight healthy volunteers with temporary mild hypovolemia underwent echography before and after passive leg raising and while wearing medical anti-shock trousers. IVC cardiac variation was visually decreased by both leg raising and medical anti-shock trousers. The collapse index (maximum - minimum/maximum) of area during three cardiac beats was decreased showing a good relationship to fluid load simulations; 0.24 ± 0.03 at baseline versus 0.11 ± 0.01 with leg raising and 0.12 ± 0.01 with medical anti-shock trousers. In conclusion, IVC cardiac variation has the potential to provide an evaluation of water volume. It presents some advantages in mechanical analysis over respiratory variation. At the very least, we need to exercise some caution with cardiac variation when evaluating respiratory variation.

Practical dosimetric aspects of blood and blood product irradiation

International Nuclear Information System (INIS)

Fearon, T.C.; Luban, N.L.

1986-01-01

The method of choice to reduce susceptibility to transfusion-transmitted graft-versus-host disease is irradiation of allogenic blood and blood products for transfusion to immunosuppressed recipients. Optimal irradiation requires delivery of a known and homogeneous absorbed dose. The use of absorbed dose in air measured at the center of the irradiation volume without proper compensation for sample absorption can lead to approximately 20 percent underexposure. A lucite cylinder was used to provide the delivery of a homogeneous irradiation dose to blood products of different volumes by allowing rotation of the product

Hyperacute stroke patients and catheter thrombolysis therapy. Correlation between computed tomography perfusion maps and final infarction

International Nuclear Information System (INIS)

Naito, Yukari; Tanaka, Shigeko; Inoue, Yuichi; Ota, Shinsuke; Sakaki, Saburo; Kitagaki, Hajime

2008-01-01

We investigated the correlation between abnormal perfusion areas by computed tomography perfusion (CTP) study of hyperacute stroke patients and the final infarction areas after intraarterial catheter thrombolysis. CTP study using the box-modulation transfer function (box-MTF) method based on the deconvolution analysis method was performed in 22 hyperacute stroke patients. Ischemic lesions were immediately treated with catheter thrombolysis after CTP study. Among them, nine patients with middle cerebral artery (MCA) occlusion were investigated regarding correlations of the size of the prolonged mean transit time (MTT) area, the decreased cerebral blood volume (CBV) area, and the final infarction area. Using the box-MTF method, the prolonged MTT area was almost identical to the final infarction area in the case of catheter thrombolysis failure. The decreased CBV areas resulted in infarction or hemorrhage, irrespective of the outcome of recanalization after catheter thrombolysis. The prolonged MTT areas, detected by the box-MTF method of CTP in hyperacute stroke patients, included the area of true prolonged MTT and the tracer delay. The prolonged MTT area was almost identical to the final infarction area when recanalization failed. We believe that a tracer delay area also indicates infarction in cases of thrombolysis failure. (author)

Evaluation of glioblastomas and lymphomas with whole-brain CT perfusion: Comparison between a delay-invariant singular-value decomposition algorithm and a Patlak plot.

Science.gov (United States)

Hiwatashi, Akio; Togao, Osamu; Yamashita, Koji; Kikuchi, Kazufumi; Yoshimoto, Koji; Mizoguchi, Masahiro; Suzuki, Satoshi O; Yoshiura, Takashi; Honda, Hiroshi

2016-07-01

Correction of contrast leakage is recommended when enhancing lesions during perfusion analysis. The purpose of this study was to assess the diagnostic performance of computed tomography perfusion (CTP) with a delay-invariant singular-value decomposition algorithm (SVD+) and a Patlak plot in differentiating glioblastomas from lymphomas. This prospective study included 17 adult patients (12 men and 5 women) with pathologically proven glioblastomas (n=10) and lymphomas (n=7). CTP data were analyzed using SVD+ and a Patlak plot. The relative tumor blood volume and flow compared to contralateral normal-appearing gray matter (rCBV and rCBF derived from SVD+, and rBV and rFlow derived from the Patlak plot) were used to differentiate between glioblastomas and lymphomas. The Mann-Whitney U test and receiver operating characteristic (ROC) analyses were used for statistical analysis. Glioblastomas showed significantly higher rFlow (3.05±0.49, mean±standard deviation) than lymphomas (1.56±0.53; P0.05), rCBF (1.38±0.41 vs. 1.29±0.47; P>0.05), or rCBV (1.78±0.47 vs. 1.87±0.66; P>0.05). ROC analysis showed the best diagnostic performance with rFlow (Az=0.871), followed by rBV (Az=0.771), rCBF (Az=0.614), and rCBV (Az=0.529). CTP analysis with a Patlak plot was helpful in differentiating between glioblastomas and lymphomas, but CTP analysis with SVD+ was not. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

Science.gov (United States)

Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

1994-01-01

Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

Impact of image denoising on image quality, quantitative parameters and sensitivity of ultra-low-dose volume perfusion CT imaging

International Nuclear Information System (INIS)

Othman, Ahmed E.; Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikoubashman, Omid; Brockmann, Marc A.; Wiesmann, Martin; Yang, Zepa; Kim, Changwon; Nikolaou, Konstantin; Kim, Jong Hyo

2016-01-01

To examine the impact of denoising on ultra-low-dose volume perfusion CT (ULD-VPCT) imaging in acute stroke. Simulated ULD-VPCT data sets at 20 % dose rate were generated from perfusion data sets of 20 patients with suspected ischemic stroke acquired at 80 kVp/180 mAs. Four data sets were generated from each ULD-VPCT data set: not-denoised (ND); denoised using spatiotemporal filter (D1); denoised using quanta-stream diffusion technique (D2); combination of both methods (D1 + D2). Signal-to-noise ratio (SNR) was measured in the resulting 100 data sets. Image quality, presence/absence of ischemic lesions, CBV and CBF scores according to a modified ASPECTS score were assessed by two blinded readers. SNR and qualitative scores were highest for D1 + D2 and lowest for ND (all p ≤ 0.001). In 25 % of the patients, ND maps were not assessable and therefore excluded from further analyses. Compared to original data sets, in D2 and D1 + D2, readers correctly identified all patients with ischemic lesions (sensitivity 1.0, kappa 1.0). Lesion size was most accurately estimated for D1 + D2 with a sensitivity of 1.0 (CBV) and 0.94 (CBF) and an inter-rater agreement of 1.0 and 0.92, respectively. An appropriate combination of denoising techniques applied in ULD-VPCT produces diagnostically sufficient perfusion maps at substantially reduced dose rates as low as 20 % of the normal scan. (orig.)

[Does autonomic diabetic neuropathy influence microcirculation reactivity in adolescents with diabetes type 1?].

Science.gov (United States)

Urban, Mirosława; Peczyńska, Jadwiga; Kowalewski, Marek; Głowińska-Olszewska, Barbara

2007-01-01

Microcirculation is known to be disturbed in many organs of diabetic patients. Retinopathy, nephropathy and neuropathy might be considered as the cause of the functional and morphological changes at the level of microcirculation. The aim of the study was to assess by means of dynamic capillaroscopy the influence of autonomic diabetic nephropathy (CAN) in adolescents with type 1 diabetes mellitus on capillary blood flow (CBV) in skin microcirculation. The study group consisted of 18 patients with type 1 diabetes mellitus (mean age 15+/-2 years). In 9 of them the diagnosis of CAN was made on the basis of Ewing tests. The control group consisted of 10 healthy persons aged 15+/-1.5 years. CBV was measured in capillars of the nailfold of the fourth finger during rest and after 2 minutes of arterial occlusion (the occlusion pressure - above 20 mmHg systolic blood pressure - was obtained by the occlusion of brachial artery using sphygnomanometer cuff). The resting CBV did not differ between patients with CAN, without CAN and healthy controls (0.39+/-0.06, 0.41+0.05 i 0.42+/-0.07). The values of the peak CBV significantly differ between the examined groups (CAN: 0.75+0.1; without CAN: 0.86+/-0.11; control group: 0.98+/-0.09, p<0.01). The obtained results indicate that the presence of the autonomic diabetic neuropathy significantly influences the regulatory function of microcirculation, which may predispose to occurrence of different late diabetic complications.

A randomized, controlled, double-blind crossover study on the effects of 1-L infusions of 6% hydroxyethyl starch suspended in 0.9% saline (voluven) and a balanced solution (Plasma Volume Redibag) on blood volume, renal blood flow velocity, and renal cortical tissue perfusion in healthy volunteers.

Science.gov (United States)

Chowdhury, Abeed H; Cox, Eleanor F; Francis, Susan T; Lobo, Dileep N

2014-05-01

We compared the effects of intravenous administration of 6% hydroxyethyl starch (maize-derived) in 0.9% saline (Voluven; Fresenius Kabi, Runcorn, United Kingdom) and a "balanced" preparation of 6% hydroxyethyl starch (potato-derived) [Plasma Volume Redibag (PVR); Baxter Healthcare, Thetford, United Kingdom] on renal blood flow velocity and renal cortical tissue perfusion in humans using magnetic resonance imaging. Hyperchloremia resulting from 0.9% saline infusion may adversely affect renal hemodynamics when compared with balanced crystalloids. This phenomenon has not been studied with colloids. Twelve healthy adult male subjects received 1-L intravenous infusions of Voluven or PVR over 30 minutes in a randomized, double-blind manner, with crossover studies 7 to 10 days later. Magnetic resonance imaging proceeded for 60 minutes after commencement of infusion to measure renal artery blood flow velocity and renal cortical perfusion. Blood was sampled, and weight was recorded at 0, 30, 60, 120, 180, and 240 minutes. Mean peak serum chloride concentrations were 108 and 106 mmol/L, respectively, after Voluven and PVR infusion (P = 0.032). Changes in blood volume (P = 0.867), strong ion difference (P = 0.219), and mean renal artery flow velocity (P = 0.319) were similar. However, there was a significant increase in mean renal cortical tissue perfusion after PVR when compared with Voluven (P = 0.033). There was no difference in urinary neutrophil gelatinase-associated liopcalin to creatinine ratios after the infusion (P = 0.164). There was no difference in the blood volume-expanding properties of the 2 preparations of 6% hydroxyethyl starch. The balanced starch produced an increase in renal cortical tissue perfusion, a phenomenon not seen with starch in 0.9% saline.

Measuring Blood Glucose Concentrations in Photometric Glucometers Requiring Very Small Sample Volumes.

Science.gov (United States)

Demitri, Nevine; Zoubir, Abdelhak M

2017-01-01

Glucometers present an important self-monitoring tool for diabetes patients and, therefore, must exhibit high accuracy as well as good usability features. Based on an invasive photometric measurement principle that drastically reduces the volume of the blood sample needed from the patient, we present a framework that is capable of dealing with small blood samples, while maintaining the required accuracy. The framework consists of two major parts: 1) image segmentation; and 2) convergence detection. Step 1 is based on iterative mode-seeking methods to estimate the intensity value of the region of interest. We present several variations of these methods and give theoretical proofs of their convergence. Our approach is able to deal with changes in the number and position of clusters without any prior knowledge. Furthermore, we propose a method based on sparse approximation to decrease the computational load, while maintaining accuracy. Step 2 is achieved by employing temporal tracking and prediction, herewith decreasing the measurement time, and, thus, improving usability. Our framework is tested on several real datasets with different characteristics. We show that we are able to estimate the underlying glucose concentration from much smaller blood samples than is currently state of the art with sufficient accuracy according to the most recent ISO standards and reduce measurement time significantly compared to state-of-the-art methods.

Cerebral blood flow in temporal lobe epilepsy: a partial volume correction study

International Nuclear Information System (INIS)

Giovacchini, Giampiero; Bonwetsch, Robert; Theodore, William H.; Herscovitch, Peter; Carson, Richard E.

2007-01-01

Previous studies in temporal lobe epilepsy (TLE) have shown that, owing to brain atrophy, positron emission tomography (PET) can overestimate deficits in measures of cerebral function such as glucose metabolism (CMR glu ) and neuroreceptor binding. The magnitude of this effect on cerebral blood flow (CBF) is unexplored. The aim of this study was to assess CBF deficits in TLE before and after magnetic resonance imaging-based partial volume correction (PVC). Absolute values of CBF for 21 TLE patients and nine controls were computed before and after PVC. In TLE patients, quantitative CMR glu measurements also were obtained. Before PVC, regional values of CBF were significantly (p glu in middle and inferior temporal cortex, fusiform gyrus and hippocampus both before and after PVC. A significant positive relationship between disease duration and AIs for CMR glu , but not CBF, was detected in hippocampus and amygdala, before but not after PVC. PVC should be used for PET CBF measurements in patients with TLE. Reduced blood flow, in contrast to glucose metabolism, is mainly due to structural changes. (orig.)

Dynamic glucose enhanced (DGE) MRI for combined imaging of blood-brain barrier break down and increased blood volume in brain cancer.

Science.gov (United States)

Xu, Xiang; Chan, Kannie W Y; Knutsson, Linda; Artemov, Dmitri; Xu, Jiadi; Liu, Guanshu; Kato, Yoshinori; Lal, Bachchu; Laterra, John; McMahon, Michael T; van Zijl, Peter C M

2015-12-01

Recently, natural d-glucose was suggested as a potential biodegradable contrast agent. The feasibility of using d-glucose for dynamic perfusion imaging was explored to detect malignant brain tumors based on blood brain barrier breakdown. Mice were inoculated orthotopically with human U87-EGFRvIII glioma cells. Time-resolved glucose signal changes were detected using chemical exchange saturation transfer (glucoCEST) MRI. Dynamic glucose enhanced (DGE) MRI was used to measure tissue response to an intravenous bolus of d-glucose. DGE images of mouse brains bearing human glioma showed two times higher and persistent changes in tumor compared with contralateral brain. Area-under-curve (AUC) analysis of DGE delineated blood vessels and tumor and had contrast comparable to the AUC determined using dynamic contrast enhanced (DCE) MRI with GdDTPA, both showing a significantly higher AUC in tumor than in brain (P blood volume and permeability with respect to normal brain. We expect DGE will provide a low-risk and less expensive alternative to DCE MRI for imaging cancer in vulnerable populations, such as children and patients with renal impairment. © 2015 Wiley Periodicals, Inc.

The Effects of TM on Concurrent Heart Rate, Peripheral Blood Pulse Volume, and the Alpha Wave Frequency.

Science.gov (United States)

Lukas, Jerome S.

Through observation of 26 subjects over a 3 month period, this research project measured the effects of transcendental meditation (TM) on concurrent heart rate, peripheral blood pulse volume, and the alpha wave frequency. The subjects were assigned randomly to three groups. One group practiced TM as prescribed by the International Meditation…

Prefrontal cerebral blood volume patterns while playing video games--a near-infrared spectroscopy study.

Science.gov (United States)

Nagamitsu, Shinichiro; Nagano, Miki; Yamashita, Yushiro; Takashima, Sachio; Matsuishi, Toyojiro

2006-06-01

Video game playing is an attractive form of entertainment among school-age children. Although this activity reportedly has many adverse effects on child development, these effects remain controversial. To investigate the effect of video game playing on regional cerebral blood volume, we measured cerebral hemoglobin concentrations using near-infrared spectroscopy in 12 normal volunteers consisting of six children and six adults. A Hitachi Optical Topography system was used to measure hemoglobin changes. For all subjects, the video game Donkey Kong was played on a Game Boy device. After spectroscopic probes were positioned on the scalp near the target brain regions, the participants were asked to play the game for nine periods of 15s each, with 15-s rest intervals between these task periods. Significant increases in bilateral prefrontal total-hemoglobin concentrations were observed in four of the adults during video game playing. On the other hand, significant decreases in bilateral prefrontal total-hemoglobin concentrations were seen in two of the children. A significant positive correlation between mean oxy-hemoglobin changes in the prefrontal region and those in the bilateral motor cortex area was seen in adults. Playing video games gave rise to dynamic changes in cerebral blood volume in both age groups, while the difference in the prefrontal oxygenation patterns suggested an age-dependent utilization of different neural circuits during video game tasks.

Plasma volume changes during hypoglycaemia

DEFF Research Database (Denmark)

Hilsted, J; Bendtsen, F; Christensen, N J

1990-01-01

To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... of albumin in arterial and venous blood in seven healthy subjects before and during insulin-induced hypoglycaemia. In both vascular sites blood 51Cr content and the haematocrit increased, plasma volume and intravascular albumin content decreased and the transcapillary escape rate of albumin increased during...

Low dose CT perfusion in acute ischemic stroke

Energy Technology Data Exchange (ETDEWEB)

Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I. [Sunnybrook Health Sciences Centre, Toronto, ON (Canada); So, Aaron; Lee, Ting-Yim [Robarts Research Institute, London, Ontario (Canada)

2014-12-15

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). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p < 0.05) followed by a paired t test post hoc analysis (p < 0.01). At 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p < 0.05). At 20 mAs, there were significant differences between the RD and LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

Evaluation of regional cerebral blood flow and volume of rapidly exchangeable water in man by positron emission tomography

International Nuclear Information System (INIS)

Depresseux, J.C.; Cheslet, J.P.; Hodiaumont, J.

1982-01-01

The present investigation uses bolus inhalation of C 15 O 2 and sequential positron emission tomography of the brain in view to simultaneously evaluate regional cerebral blood flow and regional cerebral volume of rapidly exchangeable water in normal human subjects. Arguments allow to infer that the cerebral distribution volume of radiowater does vary with time during the initial period of invasion of tissue by the indicator. Implications of this variation on the validity of classical data procedures is discussed and an alternative original method is proposed [fr

Minimal volume regulation after shrinkage of red blood cells from five species of reptiles

DEFF Research Database (Denmark)

Kristensen, Karina; Berenbrink, Michael; Koldkjær, Pia

2008-01-01

Red blood cells (RBCs) from most vertebrates restore volume upon hypertonic shrinkage and the mechanisms underlying this regulatory volume increase (RVI) have been studied extensively in these cells. Despite the phylogenetically interesting position of reptiles, very little is known about their red...... cell function. The present study demonstrates that oxygenated RBCs in all major groups of reptiles exhibit no or a very reduced RVI upon ~ 25% calculated hyperosmotic shrinkage. Thus, RBCs from the snakes Crotalus durissus and Python regius, the turtle Trachemys scripta and the alligator Alligator...... was not characterized. It seems, therefore, that the RVI response based on NHE activation was lost among the early sauropsids that gave rise to modern reptiles and birds, while it was retained in mammals. An RVI response has then reappeared in birds, but based on activation of the NKCC. Alternatively, the absence...

Assessment of red blood cell distribution width and mean platelet volume in children with epistaxis.

Science.gov (United States)

Üstün Bezgin, Selin; Çakabay, Taliye; Odaman Al, Işık

2017-04-01

This study aimed to investigate whether there is a relationship between red blood cell distribution width, mean platelet volume and epistaxis in children. Between January 2015 and July 2016, 105 children who were referred to our clinic with epistaxis and 100 sex- and age-matched controls were retrospectively analyzed. Red blood cell distribution width (RDW) and mean platelet volume (MPV) values were determined in both groups. RDW values were found significantly (P epistaxis than in the control group (11.95 ± 1.31 vs. 12.74 ± 1.21). MPV was 7.49 ± 1.33 in the group with epistaxis and 7.23 ± 1.06 in the control group, and there was no significant difference between the groups (p > 0.05). We found no difference between MPV values of both groups and significantly lower RDW values in children with epistaxis. Decreased RDW values were considered as an accompanying marker rather than a result of epistaxis. In addition, it may be thought that low RDW values may increase the bleeding tendency by disrupting the thrombotic activities. Further studies are needed to validate the relation of these parameters with epistaxis and its mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Acute CT perfusion changes in seizure patients presenting to the emergency department with stroke-like symptoms: correlation with clinical and electroencephalography findings

International Nuclear Information System (INIS)

Payabvash, S.; Oswood, M.C.; Truwit, C.L.; McKinney, A.M.

2015-01-01

Aim: To determine acute computed tomography perfusion (CTP) changes in seizure patients presenting with stroke-like symptoms and to correlate those changes with clinical presentation and electroencephalography (EEG). Materials and methods: The medical records of all patients who presented to the emergency department with acute stroke-like symptoms and underwent CTP (n=1085) over a 5.5-year period were reviewed. Patients were included who had primary seizure as the final diagnosis, and underwent CTP within 3 hours of symptom onset. A subset of patients had a follow-up EEG within 7 days. The perfusion changes and EEG findings were compared between different clinical presentations. Results: Eighteen of 1085 patients (1.7%) who underwent CTP following an acute stroke-like presentation were included. The abnormality on CTP was usually focal, unilateral hyperperfusion — increased relative cerebral blood flow (rCBF) and volume (rCBV) (n=14/18), which most often affected the temporal lobe. Those patients who presented with a motor or speech deficit (n=12) had a higher temporal lobe rCBV, and rCBF, and lower relative mean transit time (rMTT) compared to those with non-focal neurological deficit at presentation. Early EEG was available in 13 patients; a sharp-spike epileptiform EEG discharge pattern (n=5) was associated with higher temporal lobe ipsilateral rCBF and rCBV, and lower rMTT on admission CTP examination. Conclusion: Seizure patients who present with a unilateral motor or speech deficit most commonly have contralateral hyperperfusion in the corresponding eloquent brain regions on the acute-stage CTP examination. In such patients, epileptiform discharges on the early follow-up EEG are associated with ipsilateral hyperperfusion on the admission CTP. -- Highlights: •Seizure patients with stroke-mimic symptoms show contralateral hyperperfusion on acute phase CTP (<3 hours of onset). •Seizure patients with unilateral paralysis/aphasia showed asymmetric perfusion

Blood Volume: Importance and Adaptations to Exercise Training, Environmental Stresses and Trauma/Sickness

Science.gov (United States)

Sawka, Michael N.; Convertino, Victor A.; Eichner, E. Randy; Schnieder, Suzanne M.; Young, Andrew J.

2000-01-01

This paper reviews the influence of several perturbations (physical exercise, heat stress, terrestrial altitude, microgravity, and trauma/sickness) on adaptations of blood volume (BV), erythrocyte volume (EV), and plasma volume (PV). Exercise training can induced BV expansion; PV expansion usually occurs immediately, but EV expansion takes weeks. EV and PV expansion contribute to aerobic power improvements associated with exercise training. Repeated heat exposure induces PV expansion but does not alter EV. PV expansion does not improve thermoregulation, but EV expansion improves thermoregulation during exercise in the heat. Dehydration decreases PV (and increases plasma tonicity) which elevates heat strain and reduces exercise performance. High altitude exposure causes rapid (hours) plasma loss. During initial weeks at altitude, EV is unaffected, but a gradual expansion occurs with extended acclimatization. BV adjustments contribute, but are not key, to altitude acclimatization. Microgravity decreases PV and EV which contribute to orthostatic intolerance and decreased exercise capacity in astronauts. PV decreases may result from lower set points for total body water and central venous pressure, which EV decrease bay result form increased erythrocyte destruction. Trauma, renal disease, and chronic diseases cause anemia from hemorrhage and immune activation, which suppressions erythropoiesis. The re-establishment of EV is associated with healing, improved life quality, and exercise capabilities for these injured/sick persons.

Quantitative assessment of local perfusion change in acute intracerebral hemorrhage areas with and without "dynamic spot sign" using CT perfusion imaging.

Science.gov (United States)

Fu, Fan; Sui, Binbin; Liu, Liping; Su, Yaping; Sun, Shengjun; Li, Yingying

2018-01-01

Background Positive "dynamic spot sign" has been proven to be a potential risk factor for acute intracerebral hemorrhage (ICH) expansion, but local perfusion change has not been quantitatively investigated. Purpose To quantitatively evaluate perfusion changes at the ICH area using computed tomography perfusion (CTP) imaging. Material and Methods Fifty-three patients with spontaneous ICH were recruited. Unenhanced computed tomography (NCCT), CTP within 6 h, and follow-up NCCT were performed for 21 patients in the "spot sign"-positive group and 32 patients in the control group. Cerebral perfusion change was quantitatively measured on regional cerebral blood flow/regional cerebral blood volume (rCBF/rCBV) maps. Regions of interest (ROIs) were set at the "spot-sign" region and the whole hematoma area for "spot-sign"-positive cases, and at one of the highest values of three interested areas and the whole hematoma area for the control group. Hematoma expansion was determined by follow-up NCCT. Results For the "spot-sign"-positive group, the average rCBF (rCBV) values at the "spot-sign" region and the whole hematoma area were 21.34 ± 15.24 mL/min/100 g (21.64 ± 21.48 mL/100g) and 5.78 ± 6.32 mL/min/100 g (6.07 ± 5.45 mL/100g); for the control group, the average rCBF (rCBV) values at the interested area and whole hematoma area were 2.50 ± 1.83 mL/min/100 g (3.13 ± 1.96 mL/100g) and 3.02 ± 1.80 mL/min/100 g (3.40 ± 1.44 mL/100g), respectively. Average rCBF and rCBV values of the "spot-sign" region were significantly different from other regions ( P spot-sign"-positive and control groups were 25.24 ± 19.38 mL and -0.41 ± 1.34 mL, respectively. Conclusion The higher perfusion change at ICH on CTP images may reflect the contrast extravasation and be associated with the hematoma expansion.