Dynamic emission tomography of regional cerebral blood flow

International Nuclear Information System (INIS)

Lassen, N.A.

1984-01-01

The author reviews three tomographic methods for measuring the regional cerebral blood flow: single photon transmission tomography; dual photon emission tomography; and single photon emission tomography. The latter technique is discussed in detail. (Auth.)

Regional myocardial blood flow distribution during intracoronary infusion of parathyroid hormone

International Nuclear Information System (INIS)

Crass, M.F. III; Lust, R.M.

1986-01-01

Although low doses of the biologically-active fragment of parathyroid hormone PTH-(1-34), have been shown to produce potent dilation of the coronary circulation specific regional and transmural (endo/epi) myocardial blood flow (MBF) responses to the hormone have not been described. Anesthetized open-chest mongrel dogs were instrumented to quantitate coronary blood flow and other cardiodynamic parameters. PTH-(1-34) was infused into the left circumflex artery (.008 nmol kg -1 min -1 ). Using the reference withdrawal method, radionuclide-labeled microspheres were injected before (basal flow), during (8 min after new steady-state flow), and after (restoration of basal flow) a 20 min infusion of PTH-(1-34). MFB increased from 76 +- 1.9 to 152 +- 3.5 ml min -1 100 g -1 (P < .001) during PTH-(1-34) infusion. No differences in endo/epi flow ratio or regional coronary blood flow within the left ventricle were detected. Thus, in anesthetized dogs, the increase in MBF observed secondary to the PTH-(1-34)-induced decrease in coronary resistance appeared to be uniform transmurally and regionally, and is probably not the result of a shunting or steal phenomenon

Regional blood flow in experimental myositis ossificans

International Nuclear Information System (INIS)

Hierton, C.

1983-01-01

In a recent model for heterotopic bone formation, muscular oedema, swelling and necrosis is seen in the quadriceps muscle of rabbit hind limbs immobilized for at least 2 weeks when, from the second week, the immobilized limb is subjected to dayly forcible mobilization lasting about 5 min. According to this model, heterotopic calcification develops gradually from the second week of forcible mobilization and is located in the vastus intermedius region. Between the fourth and fifth week of immobilization and forcible mobilization, heterotopic bone formation is seen in virtually all cases. The histological findings are similar to those in human ectopic bone formation. In the present investigation the labelled microsphere technique was used to study the regional blood flow effects in the early development of myositis ossificans with this model. The results are quite different from those reported by other investigators on immobilization alone and point to a causal relation between regional blood flow and forcible mobilization of the immobilized rabbit hind limp. Prostaglandins as mediators between the traumatic inflammation, a part of the circulatory effects observed and the induction of a new bone is suggested. (author)

Factors affecting regional pulmonary blood flow in chronic ischemic heart disease

International Nuclear Information System (INIS)

Pistolesi, M.; Miniati, M.; Bonsignore, M.

1988-01-01

To assess the effect of left heart disease on pulmonary blood flow distribution, we measured mean pulmonary arterial and wedge pressures, cardiac output, pulmonary vascular resistance, pulmonary blood volume, and arterial oxygen tension before and after treatment in 13 patients with longstanding ischemic heart failure and pulmonary edema. Pulmonary edema was evaluated by a radiographic score, and regional lung perfusion was quantified on a lung scan by the upper to lower third ratio (U:L ratio) of pulmonary blood flow per unit of lung volume. In all cases, redistribution of lung perfusion toward the apical regions was observed; this pattern was not affected by treatment. After treatment, pulmonary vascular pressures, resistance, and edema were reduced, while pulmonary blood volume did not change. At this time, pulmonary vascular resistance showed a positive correlation with the U:L ratio (r = 0.78; P less than 0.01), whereas no correlation was observed between U:L ratio and wedge pressure, pulmonary edema, or arterial oxygen tension. Hence, redistribution of pulmonary blood flow, in these patients, reflects chronic structural vascular changes prevailing in the dependent lung regions

Disparity in regional cerebral blood flow during electrically induced seizure

DEFF Research Database (Denmark)

Sestoft, D; Meden, P; Hemmingsen, R

1993-01-01

This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized on electroencepha......This is a presentation of 2 cases in which the intraictal regional cerebral blood flow distribution was measured with the 99mTc-HMPAO single photon emission computerized tomography technique during an electrically induced seizure. Although the seizure was verified as generalized...... electroencephalography-verified generalized seizures....

Regional brain glucose metabolism and blood flow in streptozocin-induced diabetic rats

International Nuclear Information System (INIS)

Jakobsen, J.; Nedergaard, M.; Aarslew-Jensen, M.; Diemer, N.H.

1990-01-01

Brain regional glucose metabolism and regional blood flow were measured from autoradiographs by the uptake of [ 3 H]-2-deoxy-D-glucose and [ 14 C]iodoantipyrine in streptozocin-induced diabetic (STZ-D) rats. After 2 days of diabetes, glucose metabolism in the neocortex, basal ganglia, and white matter increased by 34, 37, and 8%, respectively, whereas blood flow was unchanged. After 4 mo, glucose metabolism in the same three regions was decreased by 32, 43, and 60%. This reduction was paralleled by a statistically nonsignificant reduction in blood flow in neocortex and basal ganglia. It is suggested that the decrease of brain glucose metabolism in STZ-D reflects increased ketone body oxidation and reduction of electrochemical work

Regional blood flow in the domestic fowl immediately following chronic acceleration

International Nuclear Information System (INIS)

Weidner, W.J.; Hoffman, L.F.; Clark, S.D.

1982-01-01

In order to examine the effects of chronic low G acceleration on blood flow distribution and cardiac output, chickens (N.10) were centrifuged at +2Gz for 30-61 d. Controls (N.12) were not centrifuged. The animals were anesthetized with sodium pentobarbital after removal from the centrifuge and surgically prepared in order to measure cardiac output and regional blood flows by the reference sample method with 85 Sr labeled microspheres (15 +/- 5 mum diam.). Both brachial arteries were cannulated to withdraw timed, paired blood samples at a known rate. The chest was opened and a cannula inserted into the left ventricle for administration of microspheres. Tissue samples were taken after completion of experimental procedures and their radioactivity was determined. The cardiac outputs in the two groups were not significantly different. Regional blood flows to the kidney, eyes, and skeletal muscle were significantly increased in the animals subjected to chronic +2Gz. While the mechanism by which these increases in blood flow occurred is not known, results indicate that chronic exposure to hyperdynamic gravitational fields can alter circulatory dynamics. We conclude that the cardiovascular system is directly involved in the process of adaptation to chronic positive acceleration

Effect of region assignment on relative renal blood flow estimates using radionuclides

International Nuclear Information System (INIS)

Harris, C.C.; Ford, K.K.; Coleman, R.E.; Dunnick, N.R.

1984-01-01

To determine the value of the initial phase of the Tc-99m DTPA renogram in the direct estimation of relative renal blood flow in dogs, the ratios of the slopes of renal time-activity curves were compared with the ratios of measured blood flow. Radionuclide results were dependent on region-of-interest (ROI) and background ROI assignment, and correlated well with measured relative flow only with a maximum renal outline region. Curve slope ratios correlated well with measured flow ratios with and without background correction, while 1- to 2-minute uptake ratios correlated well only when corrected for background

Regional cerebral blood flow measurement using a scintillation camera

International Nuclear Information System (INIS)

Heiss, W.D.

1979-01-01

A scintillation camera connected to auxillary equipment with off-line data processing or connected to an on-line dedicated computer system permits measurement of hemispheric and regional cerebral blood flow. Reliable flow values are obtained from regions limited in size by spatial resolution and the count rates achieved. Flow measurements obtained with the camera are able to resolve inhomogeneities of cerebral circulation in normal subjects. In a variety of clinical conditions, the localization, severity and extent of flow alterations are shown. Results of flow measurements in individual cases elucidate the pathogenesis of neurologic deficits, quantify the damage to the brain, indicate therapeutic measures of potential value and permit an estimation of the further clinical course. With restricted spatial resolution, flow measurements after intravenous 133 Xe injection are also feasible

Gender differences in regional cerebral blood flow

International Nuclear Information System (INIS)

Gur, R.E.; Gur, R.C.

1990-01-01

Gender differences have been noted in neurobehavioral studies. The 133xenon inhalation method for measuring regional cerebral blood flow (rCBF) can contribute to the understanding of the neural basis of gender differences in brain function. Few studies have examined gender differences in rCBF. In studies of normal subjects, women have higher rates of CBF than men, and this is related to age. Usually by the sixth decade men and women have similar flow rates. Fewer studies on rCBF in schizophrenia have examined sex differences. The pattern of higher flows for females maintains, but its correlates with gender differences in clinical as well as other parameters of brain function remain to be examined

Regional cerebral blood flow in diabetic patients

International Nuclear Information System (INIS)

Nagamachi, Shigeki; Ono, Shinnichi; Nishikawa, Takushi

1993-01-01

N-isopropyl-p- 123 I-iodoamphetamine (IMP) was used to quantify the regional cerebral blood flow (r-CBF) in 11 diabetic patients (average age; 67.9 years) and 12 non-diabetic subjects (average age; 67.4 years), none of whom had (cerebrovascular disease (CVD) on CT studies. A reference sampling method by continuous arterial blood sampling was used to quantify r-CBF. There were no significant differences in physiological or laboratory data between diabetic and non-diabetic groups except for fasting plasma glucose and HbA 1c levels. The average of r-CBF in each region of cerebrum and cerebellum was significantly lower in diabetic group than that in the control group (p<0.01). These observations show that r-CBF of diabetic patients is reduced, even in the absence of findings of CVD on a CT study. (author)

Potentials of positron emission tomography for regional cerebral blood flow evaluation

International Nuclear Information System (INIS)

Depresseux, J.C.

1982-01-01

A general overview of the potentials of positron emission tomography and of positron-emitting radiopharmaceuticals for the evaluation of regional cerebral blood flow is proposed and discussed. Specific characteristics of this technique are described, with special stress on conceptual and methodological implications. Four different approaches to the problem of the determination of cerebral blood flow are distinguished: trapping equilibrium methods, steady state equilibrium methods, clearance methods and convoluted kinetic methods [fr

Regional cerebral blood flow (rCBF) in psychiatry: Methodological issues

International Nuclear Information System (INIS)

Prohovnik, I.

1984-01-01

Traditionally, measurements of regional cerebral blood flow (rCBF) have been confined to neurology and nuclear medicine. Only one laboratory had concentrated on using this technique in psychiatric studies. Recently, however, rCBF has been increasingly used in psychiatry, and it seems appropriate at this time to examine the value and limitations of this method. The present article reviews selected methodological issues that may complicate the performance and interpretation of rCBF studies, with the aim of providing some means to evaluate published work and to plan further psychiatric research. In this paper, the term rCBF refers only to the two-dimensional, noninvasive methods that rely on inhalation or intravenous injection of xenon-133. The growing interest of rCBF to psychiatry stems mostly from the fact that this technique can indirectly map cerebral metabolism and, by interface, neural activity or information processing. Regional metabolism and blood flow are closely coupled to the human brain in the absence of gross pathology, and since psychiatric patients rarely present acute neurological abnormalities that might disrupt this coupling, one may infer regional metabolism from flow

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

Regional cerebral blood flow in primary degenerative dementia

International Nuclear Information System (INIS)

Kawakatsu, Shinobu; Totsuka, Shiro; Shinohara, Masao; Koyama, Hideki; Sagawa, Katsuo; Morinobu, Shigeru; Oiji, Arata; Komatani, Akio

1991-01-01

Regional cerebral blood flow (rCBF) was examined, using SPECT by Xe-133 inhalation, in patients with primary degenerative dementia who were subgrouped according to predominant symptoms with respect to amnesia, apraxia, agnosia, aphasia, and personality changes. Also the effect of sex and age at dementia onset on the rCBF patterns was assessed. (author). 26 refs.; 1 fig.; 7 tabs

Relationship between segmental thallium-201 uptake and regional myocardial blood flow in patients with coronary artery disease

International Nuclear Information System (INIS)

Nichols, A.B.; Weiss, M.B.; Sciacca, R.R.; Cannon, P.J.; Blood, D.K.

1983-01-01

The relationship between the spatial distribution of thallium-201 in myocardial perfusion scintigrams and the distribution of left ventricular regional myocardial blood flow was examined in 25 patients undergoing coronary arteriography. Thallium-201 myocardial scintigrams were obtained after symptom-limited exercise and after a 4 hr delay. Regional myocardial blood flow was measured by the xenon-133 clearance method in patients at rest and during rapid atrial pacing to a double product comparable with that achieved during exercise stress testing. Patterns of regional thallium-201 activity and regional myocardial blood flow, recorded in similar left anterior oblique projections, were compared for left ventricular segments supplied by the left anterior descending (LAD) and left circumflex (CIRC) arteries. In 11 patients without significant lesions of the left coronary artery (group 1), thallium-201 was homogeneously distributed in the LAD and CIRC distributions in scintigrams taken during peak exercise; these scintigrams correspond to homogeneous regional myocardial blood flow in the LAD and CIRC regions during pacing-induced stress. In 14 patients with significant lesions of the left coronary artery (group 2), ratios of regional thallium-201 activity in the LAD and CIRC distributions of exercise scintigrams correlated well (r . .84) with ratios of regional myocardial blood flow measured during rapid pacing. Background subtraction altered the relationship between relative thallium-201 uptake and regional myocardial blood flow, causing overestimation of the magnitude of flow reduction on exercise scintigrams

Patterns of regional cerebral blood flow in acute stroke

DEFF Research Database (Denmark)

Olsen, T S; Skriver, E B

1981-01-01

In a consecutive group of 56 stroke patients the regional cerebral blood flow was measured within 84 hours after stroke. A 254 multidetector scintillation camera and the intracarotid Xenon-133 injection method was used to study rCBF. Typical rCBF-patterns are described and compared to the findings...

Preliminary studies of regional cerebral blood flow changes in patients with leukoaraiosis

International Nuclear Information System (INIS)

Li Yaming; Ren Yan; He Qiu

1997-01-01

PURPOSE: To investigate changes of regional cerebral blood flow (rCBF) in leukoaraiosis (LA) lesion and cortical regions and analyse the relation between rCBF changes and dementia. METHODS: Regional cerebral blood flow perfusion imaging with SPECT was performed in 49 patients with subcortical multiple cerebral infarction, including 24 cases company LA [LA(+)], 25 cases not company LA[LA(-)] and 10 normal subjects. The relative analysis was made between rCBF changes and cognitive scores. RESULTS: Compared the LA(+) with control, the rCBFs in frontal, parietal, temporal cortexes and LA lesion significantly decreased (P<0.05). The rCBF of frontal, parietal cortexes and LA lesions was also significantly decreased (P<0.05) compared with LA(-) groups. The cognitive scores were significantly related with rCBF changes in frontal cortex and LA lesion (r = 0.765, P<0.01 and r = 0.439, P<0.05). CONCLUSION: In patients with subcortical multiple cerebral infarction company LA lesion, there were extensive ischemic hypoperfusion changes in the cortical regions and LA lesion, which may response to decreased cerebral function and had certain relationship with dementia. The examination with SPECT cerebral blood flow perfusion imaging had unique advantage and value

Type of aphasia and regional cerebral blood flow

International Nuclear Information System (INIS)

Tagawa, Koichi; Sugimoto, Keiko; Minematsu, Kazuo; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru

1982-01-01

In 40 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured after 2 months of ictus with 133 Xe inhalation method. There were 18 cases with motor aphasia and 22 with sensory aphasia. On the measurements of rCBF, 3 detectors were placed over frontal region (group F), 3 over temporal region (group T), and remaining 3 over parietal region (group P), of the dominant hemisphere. The flow values were compared with the rCBF values obtained from 21 control subjects who had no abnormality in CT scan and on neurological examinations. The control subjects revealed the hyperfrontal pattern of flow distribution; rCBF values in groups F, T and P, which were expressed as an initial slope index, were 50.0 +- 4.8, 48.0 +- 5.1 and 47.4 +- 4.5, respectively. The hyperfrontal pattern was absent in cases with motor aphasia. In this group, rCBF in groups F, T and P were 42.0 +- 8.3, 44.7 +- 8.4 and 41.0 +- 8.5, respectively, and rCBF in frontal region was significantly reduced compared with that in the control group. In sensory aphasia, rCBF values in groups F, T and P were all significantly reduced compared to the controls showing 44.0 +- 5.7, 42.8 +- 5.1 and 40.6 +- 5.4, respectively. In this group, the hyperfrontal pattern was maintained at a low flow level. When absolute rCBF values were compared between motor and sensory aphasia, there was no significant difference between these 2 groups. However, regional flow distribution in motor aphasia was significantly different from that of sensory aphasia, and the cases having the lowest value in group F were more frequently found in the former than in the latter. (J.P.N.)

Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility

International Nuclear Information System (INIS)

Asahi, Kouichi; Hori, M; Hamasaki, N; Sato, S; Nakanishi, H; Kuwatsuru, R; Sasai, K; Aoki, S

2012-01-01

It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-contrast (2DPC) MRA, respectively. Regional cerebral blood flow was visualized with territorial arterial spin-labeling magnetic resonance imaging (TASL-MRI). TASL-MRI and 2DPC-MRA were performed in three states: at rest, during manual compression of the right carotid artery, and after decompression. In one volunteer, time-space labeling inversion pulse (Time-SLIP) MRA was performed to confirm collateral flow. During manual carotid compression, in one volunteer, the right thalamus changed to be fed only by the vertebrobasilar system, and the right basal ganglia changed to be fed by the left internal carotid artery. In the other volunteer, the right basal ganglia changed to be fed by the vertebrobasilar system. 2DPC-MRA showed that the flow direction changed in the right A1 segment of the anterior cerebral artery and the right posterior communicating artery. Perfusion patterns and flow directions recovered after decompression. Time-SLIP MRA showed pial vessels and dural collateral circulation when the right carotid artery was manually compressed. Use of TASL-MRI and 2DPC-MRA was successful for non-invasive visualization of the dynamic changes in regional cerebral blood flow during and after manual carotid compression

Regional cerebral blood flow in patients with hypertensive intracerebral hemorrhage

International Nuclear Information System (INIS)

Kuroda, Kiyoshi

1982-01-01

Regional cerebral blood flow (rCBF) was measured in 36 patients with hypertensive intracerebral hemorrhage (putaminal hemorrhage) treated surgically, using the Xenon-133 intracarotid injection method. The correlations between CBF in four regions, (the hemisphere, the frontal region, the sensori-motor area and the focal area) and the duration from the operation, the conscious level, the hematoma volume and motor function were investigated. Mean cerebral blood flow (MCBF), rCBF in sensori-motor area and in the focal area showed a value below 30 ml/100g/min. for any duration after the operation within one year. However, in the frontal region rCBF tends to increase from 4 months after the operation. There was a close correlation between the conscious level and CBF, especially in the frontal region. The higher CBF was noted in the better consciousness group. In hematoma cases the larger the hematoma volume (especially those over 31 ml)the lower the CBF in all three regions. In the focal area rCBF showed the lowest value among these three regions and was dependent on the hematoma volume, while frontal region revealed the highest flow value of them all, even in cases with a hematoma volume over 81 ml. There was a significant difference in rCBF between cases with severe motor disturbance and cases with moderate motor disturbance, except in the focal area. In the frontal region rCBF coincides rather well to the degree of motor disturbance. While, rCBF in the focal area was less than 30 ml/100g/min., and showed no correlation to motor function. (J.P.N.)

Single-photon tomographic determination of regional cerebral blood flow in epilepsy

International Nuclear Information System (INIS)

Bonte, F.J.; Devous, M.D. Sr.; Stokely, E.M.; Homan, R.W.

1983-01-01

Using a single-photon emission computed tomographic scanner (SPECT) the authors determined regional cerebral blood flow (rCBF) with inhaled xenon-133, a noninvasive procedure. Studies were performed in 40 normal individuals, and these were compared with rCBF determinations in 51 patients with seizure disorders. Although positive results were obtained in 15 of 16 patients with mass lesions, the group of principal interest comprised 25 patients suffering from ''temporal lobe'' epilepsy. Only one of these had a positive x-ray computed tomogram, but 16 had positive findings on rCBF study. These findings included increased local blood flow in the ictal state and reduced flow interictally

[Regional blood flow and bone uptake of methylene-diphosphonate-technetium-99m].

Science.gov (United States)

Vattimo, A; Martini, G; Pisani, M

1983-05-30

Sudeck's atrophy of the foot is an acute, patchy osteoporosis that, on bone scan, shows an increase in both bone blood flow and local bone uptake of bone-seeking radionuclides. The purpose of this study was to evaluate the relationship between bone uptake of 99mTc-MDP and local bone blood flow. In some patients with Sudeck's atrophy of one foot we measured local bone blood flow and bone uptake of 99mTc-MDP. External counting of radioactivity, with a count-rate of 1 second was performed for 60 minutes after i.v. injection of a known dose of 99mTc-MDP in some patients with Sudeck's atrophy of the foot. The regions of interest (ROI) were selected on the basis of a bone scan performed 24 hours earlier. We assumed that the data recorded during the first seconds (7-10) reflect local blood flow and the data at 60 minutes reflect the bone uptake. The ratio between the local blood flow in the involved and healthy foot was higher than the local bone uptake ratio. The ratio between bone uptake and local bone blood flow was higher in the normal foot than in the affected one. These results suggest that the bone avidity for bone-seeking radionuclides is lower in Sudeck's atrophy than in normal bone.

Regional cerebral blood flow in Parkinson's disease by [sup 123]I-IMP SPECT

Energy Technology Data Exchange (ETDEWEB)

Kitamura, Yoshihiro [Okayama Univ. (Japan). School of Medicine

1994-06-01

Regional cerebral blood flow (rCBF) was evaluated in 63 patients with Parkinson's disease (PD) by single-photon emission computed tomography (SPECT) using N-isopropyl-p-[sup 123]I-iodoamphetamine ([sup 123]I-IMP) as a tracer. Evaluation of the SPECT images was performed in accordance with the rCBF quantification method using a microsphere model. Patients in stage IV demonstrated significantly lower rCBF than those in stage II at the frontal, temporal, parietal, occipital regions and in the thalamus and cerebellum. Subjects with mental symptoms demonstrated decreased rCBF in every region in the brain. The present study indicates that clinical exacerbation and manifestation of dementia and other psychiatric symptoms in Parkinson's disease are associated with decreased blood flow in various brain regions. (author).

pO2 and regional blood flow in a rabbit model of limb ischemia.

Science.gov (United States)

Grinberg, Oleg Y; Hou, Huagang; Grinberg, Stalina A; Moodie, Karen L; Demidenko, Eugene; Friedman, Bruce J; Post, Mark J; Swartz, Harold M

2004-06-01

Oxygen tension (pO2) in muscles and regional blood flow were measured in a rabbit model of limb ischemia. pO2 was measured repetitively by EPR oximetry with EMS char in four different muscle groups in the same animals. Blood flow in the same muscles at several time points was measured using microspheres. A linear mixed effects model was developed to analyze the data on pO2 and blood flow. The results suggest that while under normal conditions pO2 in muscles does not depend significantly on blood flow, immediately after arterial occlusion pO2 correlates linearly with blood flow. Within two weeks of occlusion the pO2 is recovered to 45% of baseline. This study demonstrates, for the first time, the applicability of EPR oximetry in animals larger than rodents.

Regional cerebral blood flow in older patients with chronic subdural hematoma

International Nuclear Information System (INIS)

Hoshi, Yutaka; Fuse, Masaaki; Iio, Masahiro; Fuziwara, Keigo; Kawaguchi, Shinichiro

1978-01-01

Regional cerebral blood flow (rCBF) was measured in 4 regions (frontal, parietal, occipital, and temporal) over the entire hemisphere using modified 133 Xe clearance method in 5 patients with chronic subdural hematoma. In 5 patients, rCBF was measured both pre- and postoperation and those values were compared. CBF (average cerebral blood flow) measurements were compared. CBF measurements were carried out in each patients respectively, that is before the operation and 3 weeks after the operation. Before the operation, the presence of chronic subdural hematoma, but brought about only slight or moderate generalized decrease in rCBF. The older patients presented subnormal values of 31.5 - 45.1 ml/100 g/min. Mean f sub(g) (the flow in the grey matter) of 5 patients was 66.8 +- 5.0 ml/100 g/min on the hematoma site, 58.1 +- 2.8 ml/100 g/min on the non-hematoma site before operation. Three weeks after operation mean f sub(g) was 65.5 +- 7.6 ml/100 g/min on the non-hematoma site, 64.2 +- 3.5 ml/100 g/min on the hematoma site, and CBFr of non-hematoma site was 40.2 +- 5.7 ml/100 g/min and that of hematoma site, 38.5 +- 8.8 ml/100 g/min. These figures are moderately smaller than that of the normal values. A comparison between regional flow values noted in patients of pre- and post-operation who has a removal of hematomas indicated that the flow values of non-hematoma site increased slightly 3 weeks after operation, inspite of the only slight or no improvement in neurological features. But the flow values (f sub(g), CBFr) of hematoma site decreased 3 weeks after operation. It seems that post-operative follow up of mean cerebral blood flow change might be of help in the assessment of prognosis of operation. (auth.)

Regional cerebral blood flow in older patients with chronic subdural hematoma

Energy Technology Data Exchange (ETDEWEB)

Hoshi, Y; Fuse, M; Iio, M; Fuziwara, K; Kawaguchi, S [Tokyo Metropolitan Geriatric Medical Center (Japan)

1978-02-01

Regional cerebral blood flow (rCBF) was measured in 4 regions (frontal, parietal, occipital, and temporal) over the entire hemisphere using modified /sup 133/Xe clearance method in 5 patients with chronic subdural hematoma. In 5 patients, rCBF was measured both pre- and postoperation and those values were compared. CBF (average cerebral blood flow) measurements were compared. CBF measurements were carried out in each patients respectively, that is before the operation and 3 weeks after the operation. Before the operation, the presence of chronic subdural hematoma, but brought about only slight or moderate generalized decrease in rCBF. The older patients presented subnormal values of 31.5 - 45.1 ml/100 g/min. Mean f sub(g) (the flow in the grey matter) of 5 patients was 66.8 +- 5.0 ml/100 g/min on the hematoma site, 58.1 +- 2.8 ml/100 g/min on the non-hematoma site before operation. Three weeks after operation mean f sub(g) was 65.5 +- 7.6 ml/100 g/min on the non-hematoma site, 64.2 +- 3.5 ml/100 g/min on the hematoma site, and CBFr of non-hematoma site was 40.2 +- 5.7 ml/100 g/min and that of hematoma site, 38.5 +- 8.8 ml/100 g/min. These figures are moderately smaller than that of the normal values. A comparison between regional flow values noted in patients of pre- and post-operation who has a removal of hematomas indicated that the flow values of non-hematoma site increased slightly 3 weeks after operation, inspite of the only slight or no improvement in neurological features. But the flow values (f sub(g), CBFr) of hematoma site decreased 3 weeks after operation. It seems that post-operative follow up of mean cerebral blood flow change might be of help in the assessment of prognosis of operation.

The influence of gravity on regional lung blood flow in humans: SPECT in the upright and head-down posture.

Science.gov (United States)

Ax, M; Sanchez-Crespo, A; Lindahl, S G E; Mure, M; Petersson, J

2017-06-01

Previous studies in humans have shown that gravity has little influence on the distribution of lung blood flow while changing posture from supine to prone. This study aimed to evaluate the maximal influence of posture by comparison of regional lung blood flow in the upright and head-down posture in 8 healthy volunteers, using a tilt table. Regional lung blood flow was marked by intravenous injection of macroaggregates of human albumin labeled with 99m Tc or 113m In, in the upright and head-down posture, respectively, during tidal breathing. Both radiotracers remain fixed in the lung after administration. The distribution of radioactivity was mapped using quantitative single photon emission computed tomography (SPECT) corrected for attenuation and scatter. All images were obtained supine during tidal breathing. A shift from upright to the head-down posture caused a clear redistribution of blood flow from basal to apical regions. We conclude that posture plays a role for the distribution of lung blood flow in upright humans, and that the influence of posture, and thereby gravity, is much greater in the upright and head-down posture than in horizontal postures. However, the results of the study demonstrate that lung structure is the main determinant of regional blood flow and gravity is a secondary contributor to the distribution of lung blood flow in the upright and head-down positions. NEW & NOTEWORTHY Using a dual-isotope quantitative SPECT method, we demonstrated that although a shift in posture redistributes blood flow in the direction of gravity, the results are also consistent with lung structure being a greater determinant of regional blood flow than gravity. To our knowledge, this is the first study to use modern imaging methods to quantify the shift in regional lung blood flow in humans at a change between the upright and head-down postures. Copyright © 2017 the American Physiological Society.

The effects of activation procedures on regional cerebral blood flow in humans

International Nuclear Information System (INIS)

Rozenfeld, D.; Wolfson, L.I.

1981-01-01

Regional cerebral blood flow (r-CBF) can be measured using 133XE and collimated detectors. The radionuclide can be administered either by inhalation or intracarotid injection. Comparison of blood flow determinations at rest and during performance of an activity identifies those brain regions that become active during the performance of the activity. Relatively specific patterns of r-CBF are observed during hand movements, sensory stimulation, eye movements, speech, listening, and reading. Regional CBF changes during reasoning and memorization are less specific and less well characterized. It is clear that brain lesions affect r-CBF responses to various activities, but this effect has not been well correlated with functional deficits or recovery of function. Regional CBF measurement gives information about brain activity and the functional response to experimental manipulation. This approach may well add to our understanding of normal, as well as pathologic, brain functioning

Cardiac output and regional blood flow following trauma

International Nuclear Information System (INIS)

Malik, A.B.; Loegering, D.J.; Saba, T.M.; Kaplan, J.E.

1978-01-01

The changes in cardiac output (2), regional blood blow (2r) and regional vascular resistance, and arterial pressure were studied in rats subjected to moderate (LD0) or severe (LD50) traumatic shock. 2 and 2r were determined using microspheres at 15, 60 and 180 min posttrauma. Arterial pressure decreased in both groups at 15 min and recovered by 3 h after sublethal (LD0) trauma, while arterial pressure did not return to control levels after LD50 trauma. 2 decreased in both groups at 15 min and returned to control only in the LD0 trauma group by 3 h. Cerebral, coronary, and hepatic arterial flows and resistances were maintained in both groups. Renal, intestinal, and splenic flows decreased and resistances were maintained in both groups. Renal, intestinal, and splenic flows decreased and resistances increased in both groups by 15 min and returned to control levels by 3 h only in the LD0 trauma group. Total hepatic and hepatic portal flows decreased at 60 min and returned to control levels at 3 h after LD0 trauma, while there was significant depression in these parameters 3 h after LD50 trauma. Therefore, sublethal and severe trauma resulted in early redistribution of flow favoring the coronary, cerebral, and hepatic arterial beds. However, renal, intestinal, splenic, and portal flows remained depressed only in severely traumatized rats, suggesting that continued hypofusion is a factor in the multiple organ failure and death following severe traumatic injury

Low regional cerebral blood flow in burning mouth syndrome patients with depression.

Science.gov (United States)

Liu, B-L; Yao, H; Zheng, X-J; Du, G-H; Shen, X-M; Zhou, Y-M; Tang, G-Y

2015-07-01

The main aims of this study were to (i) investigate the emotional disorder status of patients with burning mouth syndrome (BMS) and (ii) detect regional cerebral blood flow in BMS patients with the application of combined single-photon emission computed tomography and computed tomography (SPECT/CT). The degree of pain was measured using the visual analysis scale, and emotional disorder with the self-rating anxiety scale, self-rating depression scale, and Hamilton depression rating scale in 29 patients with BMS and 10 healthy controls. SPECT/CT was performed in 29 patients with BMS and 10 healthy controls, and statistical parametric mapping method was used for between-group analyses. The incidence rate of depression in patients with BMS was 31.0%. Compared to the control group, patients with BMS displayed significantly different depression and anxiety scales (P < 0.05). Significantly lower regional cerebral blood flow in the left parietal and left temporal lobes was recorded for BMS patients with depression (P < 0.05). Patients with BMS experience more depression and anxious emotion. Moreover, depression in patients with BMS may be associated with lower regional cerebral blood flow in the left temporal and left parietal lobes. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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)

Regional cerebral blood flow after long-term exposure to carbon disulfide

International Nuclear Information System (INIS)

Aaserud, O.; Russell, D.; Nyberg-Hansen, R.; Joergensen, E.B.; Gjerstad, L.; Rootwelt, K.; Nakstad, P.; Hommeren, O.J.; Tvedt, B.

1992-01-01

Sixteen former rayon viscose workers were investigated four years after the exposure to carbon disulfide was discontinued. Median age was 58 years (range 43-65 years), median exposure time was 17 years (range 10-35 years). Encephalopathy was diagnosed in altogether 14 workers. To further explore pathophysiological mechanisms, cerebrovascular investigations were employed. Doppler ultrasound examination of the precerebral vessels in 15 workers showed a slight stenosis of the left internal carotid artery in one. Regional cerebral blood flow investigation (rCBF) with single photon emission computerized tomography (SPECT) with Xenon-133 gas was performed in 14. There was no significant difference from a control group. Regional side-to-side asymmetries beyond reference limits were demonstrated in eight workers. The abnormalities were modest, but may indicate a tendency toward focal blood flow disturbances in workers with long-term exposure to carbon disulfide. (au)

Regional differences in the skin blood flow at various sites of the body studied by xenon 133

International Nuclear Information System (INIS)

Tsuchida, Y.

1987-01-01

Normal skin blood flow was measured by the xenon 133 clearance method at different anatomic sites of the body and the following results were obtained. First, the skin blood flow of the face and anterior chest was significantly greater than that of the deltoid region (P less than 0.01). The skin blood flow of the dorsal side of the hand and foot was significantly lower than that of the deltoid region (P less than 0.01). A tendency was observed for the skin blood flow to decrease gradually from the upper part of the body to the lower part of the body. For example, the ratio of the highest value at the face to the lowest value at the dorsal side of the foot was about 2.5:1, indicating a remarkable difference among the various sites of the body. The skin blood flow at the dorsum of the hand was significantly higher by about 25.4 percent than that of the foot (P less than 0.01). Second, the skin blood flow at the left side of the deltoid region was higher by about 5 percent than that of the right side (P less than 0.01). Bilateral comparison of the skin blood flow at the dorsal side of the hand and foot showed that the values were almost the same on the left and right

Regional cerebral blood flow and CSF pressures during Cushing response induced by a supratentorial expanding mass

International Nuclear Information System (INIS)

Schrader, H.; Zwetnow, N.N.; Moerkrid, L.

1985-01-01

In order to delineate the critical blood flow pattern during the Cushing response in intracranial hypertension, regional cerebral blood flow was measured with radioactive microspheres in 12 anesthetized dogs at respiratory arrest caused either by expansion of an epidural supratentorial balloon or by cisternal infusion. Regional cerebrospinal fluid pressures were recorded and the local cerebral perfusion pressure calculated in various cerebrospinal compartments. In the 8 dogs of the balloon expansion group, the systemic arterial pressure was unmanipulated in 4, while it was kept at a constant low level (48 and 70 mm Hg) in 2 dogs and, in another 2 dogs, at a constant high level (150 and 160 mm Hg) induced by infusion of Aramine. At respiratory arrest, regional cerebral blood flow had a stereotyped pattern and was largely independent of the blood pressure level. In contrast, concomitant pressure gradients between the various cerebrospinal compartments varied markedly in the 3 animal groups increasing with higher arterial pressure. Flow decreased by 85-100% supratentorially and by 70-100% in the upper brain stem down to the level of the upper pons, while changes in the lower brain stem were minor, on the average 25%. When intracranial pressure was raised by cisternal infusion in 4 dogs, the supratentorial blood flow pattern at respiratory arrest was appriximately similar to the flow pattern in the balloon inflation group. However, blood flow decreased markedly (74-85%) also in the lower brain stem. The results constitute another argument in favour of the Cushing response in supratentorial expansion being caused by ischemia in the brain stem. The critical ischemic region seems to be located rostrally to the oblongate medulla, probably in the pons. (author)

Regional cerebral blood flow in pure dysarthria. A 3D-SSP study

International Nuclear Information System (INIS)

Okamoto, Kensho; Kamogawa, Kenji; Okuda, Bungo; Kawabata, Keita; Tachibana, Hisao

2007-01-01

Pure dysarthria from brain infarction is a rare condition, and its pathophysiology remains unclear. To clarify the underlying mechanism of pure dysarthria, we investigated the lesion sites and regional cerebral blood flow in patients with pure dysarthria. We examined 18 consecutive patients with pure dysarthria (9 men and 9 women; mean age, 71 years) who underwent MRI and cerebral blood flow studies. To visualize the regional cerebral blood flow, we generated Z score images using the three-dimensional stereotactic surface projection (3D-SSP) method with single-photon emission computed tomography (SPECT) and N-isopropyl-p [ 123 I]iodoamphetamine. Data on the brain surface perfusion extracted by the 3D-SSP analysis were compared between the pure dysarthria (PD) patients and 9 control subjects. MRI revealed multiple lacunar infarctions involving the internal capsule and/or corona radiata in 11 patients, left internal capsule-corona radiata infarction in 4 patients, and pontine infarction in 3 patients. SPECT with 3D-SSP demonstrated bilateral frontal cortical hypoperfusion in all patients, particularly in the anterior opercular region. Based on intergroup comparisons, the PD group exhibited pronounced cortical hypoperfusion in the opercular and medial frontal regions, left more than right. In conclusion, pure dysarthria is considered to originate from frontal cortical hypoperfusion, mainly in the anterior opercular and medial frontal regions, which is probably due to interruption of the corticosubcortical neural networks relevant to speech expression and articulation. In addition, it is suggested that left hemispheric lesions may make a greater contribution to the development of pure dysarthria than do right ones. (author)

Quantitative evaluation of regional cerebral blood flow by visual stimulation in 99mTc-HMPAO brain SPECT

International Nuclear Information System (INIS)

Juh, R. H.; Suh, T. S.; Chung, Y. A.

2002-01-01

The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50±5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann

Quantitative evaluation of regional cerebral blood flow by visual stimulation in 99mTc- HMPAO brain SPECT

International Nuclear Information System (INIS)

Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo

2002-01-01

The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9 9m Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99m Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50±5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann

Measurement of regional cerebral blood flow by positron emission tomography

International Nuclear Information System (INIS)

Herscovitch, P.; Powers, W.J.

1987-01-01

The principal advantage of positron emission tomography over other methods for measuring cerebral blood flow stems from the accurate, quantitative three-dimensional measurements of regional brain radioactivity that are possible with this technique. As a result, accurate quantitative measurements of regional cerebral blood flow can be obtained for both superficial and deep cerebral structures. The value of PET for investigating central nervous system physiology and pathology extends far beyond this, however. Through the use of different radiotracers and appropriate mathematical models, PET can be applied to the measurement of a wide variety of physiologic variables. Measurements of rCBF tell only part of the story. Experience with PET and with a variety of other techniques has taught us that rCBF is at times a poor indicator of the metabolic, functional, and biochemical status of cerebral tissue. It is only by understanding the interaction of all of these factors that our understanding of neurologic disease can advance. It is in the investigation of these complex relationships that the real value of PET resides

Regional blood flows in the established stage of reduced renal mass (RRM) hypertension in rats

International Nuclear Information System (INIS)

Smits, G.J.; Lombard, J.H.

1986-01-01

Regional blood flows were measured with 15 μm 153 Gd-labelled microspheres in 21 anesthetized (pentobarbital-50 mg/kg, i.p.) male Sprague Dawley rats 5-6 weeks after a 75% reduction in renal mass and in 6 sham operated controls (SOC). RRM rats were maintained on either a high salt (HS-RRM) diet, i.e., choice of 1% NaCl or tap water (n = 11), or on a salt-restricted (SR-RRM) diet (n = 10). Mean arterial blood pressure was significantly elevated (mean +/- SE) in the HS-RRM (168 +/- 5 mmHg) vs. either the SR-RRM (147 +/- 6 mmHg) or the SOC (138 +/- 4 mmHg). Although blood flow to the skin and femur were elevated in HS-RRM and SR-RRM relative to SOC, there were no significant differences in blood flow to skeletal muscle, spleen, liver, small intestine, stomach or testes between any of the groups. Absolute renal blood flow and renal blood flow/gm of tissue were significantly lower in HS-RRM (7.2 +/- 0.7 ml/min or 3.4 +/- 0.5 ml/min/gm) and SR-RRM (6.3 +/- 0.6 ml/min or 3.2 +/- 0.3 ml/min/gm) than in SOC (15.1 +/- 0.97 ml/min or 5.5 +/- 0.2 ml/min/gm). The present results suggest that regional blood flow is unchanged in most vascular beds during the established stage of RRM hypertension in rats

Measurement of regional cerebral blood flow by intravenous administation of 133 xenon

International Nuclear Information System (INIS)

Ryding, E.

1986-01-01

Reviewing the background and the theory for rCFB measurements the following conditions are established for the use of flow measurement with 133-Xenon as a reliable indicator for indirect measurements of cerebral functional activity. 1. There is a strict coupling between rCBF and regional metabolism. This condition can only be considered to be fulfilled in the normal non-anoxic bran tissue. 2. There is a close correlation between the tissue and the venous concentration of 133-Xenin which can be reliably approximated by the blood-brain partition coefficient. This condition can be considered to be fullfilled in the normal flow range, but not in pathological conditions such as cerebrovascular occlusions. 3. Intercompartment diffusion of 133-Xenon has no significant effect upon the measurement of rCBF values. This condition appear to share its limitations for fulfilement with condition 2. 4. There is no significant contamination by the extracerebral flow components at IH or IV rCBF measurements. 5. There is a negligible 'look through' effect from surrounding areas to region with focal high or low blood flow. (U.W.)

Effects of thyrotropin-releasing hormone on regional cerebral blood flow in man

DEFF Research Database (Denmark)

Oturai, P S; Friberg, L; Sam, I

1992-01-01

emission computerized tomograph and inhalation of 133Xe. Thyrotropin-releasing hormone caused a significant mean increase of 3.7% (range -8.8-22.7) in blood flow in a region consistent with the left thalamus compared to placebo (3.2% decrease). In 25 other regions no significant change was detected...

Receiver operating characteristic analysis of regional cerebral blood flow in Alzheimer's disease

International Nuclear Information System (INIS)

Zemcov, A.; Barclay, L.L.; Sansone, J.; Metz, C.E.

1985-01-01

Receiver operating characteristic (ROC) curves were used to quantitatively assess the ability of individual detectors in a 32-detector 133 Xe inhalation system to discriminate between two populations over the range of regional cerebral blood flow (rCBF) values. These populations were clinically evaluated as normal (age 63.1 +/- 13.1, n = 23) and presumed Alzheimer's disease (age 72.7 +/- 7.0, n = 82). Summary statistics showed that for homologous detectors the average value of blood flow in the normal group was greater than the flow value in the group of subjects with Alzheimer's disease. Conclusions drawn from single values of flow or mean hemispheric flow can lead to erroneous conclusions about hemisphere asymmetries. However, the dynamic relationship between the correct identifications (true positives) compared with incorrect identifications (false positives) of Alzheimer's disease at each detector varies over the range of blood flow values, and quantitative characterization of this relationship in terms of an ROC curve provides more insight into the structure of the data. Detectors approximating the speech, auditory and association cortex were most effective in discriminating between groups. Frontal detectors were marginally useful diagnostically

Regional cerebral blood flow during mechanical hyperventilation in patients with acute bacterial meningitis

DEFF Research Database (Denmark)

Møller, Kirsten; Høgh, Peter; Larsen, Fin Stolze

2000-01-01

Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial...... meningitis before and during short-term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min-1) was measured during baseline ventilation and hyperventilation by single-photon emission computed tomography (SPECT) using intravenous 133Xe bolus injection. Intravenous...... in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short-term hyperventilation does not enhance these abnormalities....

Regional blood flow studies with radioisotopes

International Nuclear Information System (INIS)

Holman, B.L.; McNiel, B.J.; Adelstein, S.J.

1975-01-01

The methodological approaches to blood flow analysis include (1) diffusible indicator methods, (2) clearance techniques and (3) nondiffusible indicator methods. In each case, accurate measurements of blood flow can be obtained by developing mathematical models which relate the time-dependent observation derived from following the fate of a radiotracer as a function of time to the physiological process itself. Application of these models to biological systems involves constraints and necessitates compromises which may affect the validity of the measurements. Nevertheless, when these techniques are carefully applied and adequately validated, they have provided critical physiological information about such organ systems as the brain and kidney and promise to provide diagnostic information in patients with suspected coronary and peripheral vascular disease

Assessing regional cerebral blood flow in depression using 320-slice computed tomography.

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Yiming Wang

Full Text Available While there is evidence that the development and course of major depressive disorder (MDD symptomatology is associated with vascular disease, and that there are changes in energy utilization in the disorder, the extent to which cerebral blood flow is changed in this condition is not clear. This study utilized a novel imaging technique previously used in coronary and stroke patients, 320-slice Computed-Tomography (CT, to assess regional cerebral blood flow (rCBF in those with MDD and examine the pattern of regional cerebral perfusion. Thirty nine participants with depressive symptoms (Hamilton Depression Rating Scale 24 (HAMD24 score > 20, and Self-Rating Depression Scale (SDS score > 53 and 41 healthy volunteers were studied. For all subjects, 3 ml of venous blood was collected to assess hematological parameters. Transcranial Doppler (TCD ultrasound was utilized to measure parameters of cerebral artery rCBFV and analyse the Pulsatility Index (PI. 16 subjects (8 =  MDD; 8 =  healthy also had rCBF measured in different cerebral artery regions using 320-slice CT. Differences among groups were analyzed using ANOVA and Pearson's tests were employed in our statistical analyses. Compared with the control group, whole blood viscosity (including high\\middle\\low shear rateand hematocrit (HCT were significantly increased in the MDD group. PI values in different cerebral artery regions and parameters of rCBFV in the cerebral arteries were decreased in depressive participants, and there was a positive relationship between rCBFV and the corresponding vascular rCBF in both gray and white matter. rCBF of the left gray matter was lower than that of the right in MDD. Major depression is characterized by a wide range of CBF impairments and prominent changes in gray matter blood flow. 320-slice CT appears to be a valid and promising tool for measuring rCBF, and could thus be employed in psychiatric settings for biomarker and treatment response purposes.

Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

1979-01-01

Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

International Nuclear Information System (INIS)

Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

1979-01-01

Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined

Regional Myocardial Blood Volume and Flow: First-Pass MR Imaging with Polylysine-Gd-DTPA

Science.gov (United States)

Wilke, Norbert; Kroll, Keith; Merkle, Hellmut; Wang, Ying; Ishibashi, Yukata; Xu, Ya; Zhang, Jiani; Jerosch-Herold, Michael; Mühler, Andreas; Stillman, Arthur E.; Bassingthwaighte, James B.; Bache, Robert; Ugurbil, Kamil

2010-01-01

The authors investigated the utility of an intravascular magnetic resonance (MR) contrast agent, poly-L-lysine-gadolinium diethylenetriaminepentaacetic acid (DTPA), for differentiating acutely ischemic from normally perfused myocardium with first-pass MR imaging. Hypoperfused regions, identified with microspheres, on the first-pass images displayed significantly decreased signal intensities compared with normally perfused myocardium (P < .0007). Estimates of regional myocardial blood content, obtained by measuring the ratio of areas under the signal intensity-versus-time curves in tissue regions and the left ventricular chamber, averaged 0.12 mL/g ± 0.04 (n = 35), compared with a value of 0.11 mL/g ± 0.05 measured with radiolabeled albumin in the same tissue regions. To obtain MR estimates of regional myocardial blood flow, in situ calibration curves were used to transform first-pass intensity-time curves into content-time curves for analysis with a multiple-pathway, axially distributed model. Flow estimates, obtained by automated parameter optimization, averaged 1.2 mL/min/g ± 0.5 [n = 29), compared with 1.3 mL/min/g ± 0.3 obtained with tracer microspheres in the same tissue specimens at the same time. The results represent a combination of T1-weighted first-pass imaging, intravascular relaxation agents, and a spatially distributed perfusion model to obtain absolute regional myocardial blood flow and volume. PMID:7766986

Relationship between regional myocardial blood flow and thallium-201 distribution in the presence of coronary artery stenosis and dipyridamole-induced vasodilation

International Nuclear Information System (INIS)

Mays, A.E. Jr.; Cobb, F.R.

1984-01-01

This study assesses the relationship between the distribution of thallium-201 and myocardial blood flow during coronary vasodilation induced by intravenous dipyridamole in canine models of partial and complete coronary artery stenosis. 10 dogs were chronically instrumented with catheters in the left atrium and aorta and with a balloon occluder and electromagnetic flow probe on the proximal left circumflex coronary artery. Regional myocardial blood flow was measured during control conditions with radioisotope-labeled microspheres, and the phasic reactive hyperemic response to a 20-s transient occlusion was then recorded. Dipyridamole was then infused intravenously until phasic coronary blood flow increased to match peak hyperemic values. The left circumflex coronary artery was either partially occluded to reduce phasic blood flow to control values (group 1) or it was completely occluded (group 2), and thallium-201 and a second microsphere label were injected. 5 min later, the animals were sacrificed, the left ventricle was sectioned into 1-2-g samples, and thallium-201 activity and regional myocardial blood flow were measured. Curvilinear regression analyses between thallium-201 localization and myocardial blood flow during dipyridamole infusion demonstrated a slightly better fit to a second- as compared with a first-order model, indicating a slight roll-off of thallium activity as myocardial blood flow increases. During the dipyridamole infusion, the increases in phasic blood flow, the distributions of regional myocardial blood flow, and the relationships between thallium-201 localization and regional blood flow were comparable to values previously observed in exercising dogs with similar occlusions. These data provide basic validation that supports the use of intravenous dipyridamole and thallium-201 as an alternative to exercise stress and thallium-201 for evaluating the effects of coronary occlusive lesions on the distribution of regional myocardial blood flow

Quantitative determination of the regional cerebral blood flow with 133Xe

International Nuclear Information System (INIS)

Otto, H.J.; Abraham, K.; Freitag, J.; Koch, R.D.; Freitag, G.; Hoefs, R.

1982-01-01

After injection of 133 Xe into the A. carotis interna, the regional blood flow in the brain was determined with a 10-channel measuring unit. From the first clinical evaluation of the findings in 35 patients, the following conclusions can be drawn: 1. In epileptics, a localized hyperemia indicates very probably a latent increased convulsive activity. 2. The measurement of the cerebral blood flow does not yield a contribution to the diagnosis of the type of cerebral tumors. 3. As consequence of mass shifting of space occupying processes particularly endangered brain sections, also remote from the focus proper, show a localized pathological hyeperemia (morbid 'luxus perfusion'). 4. Of greatest importance is the method with regard to the elucidation of pathophysiological relations, as well as of questions in connection with the blood/brain barrier function, and concerning the indication for and the estimation of the results of vascular interventions. (author)

Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc- HMPAO brain SPECT

Energy Technology Data Exchange (ETDEWEB)

Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo [College of Medicine, The Catholic Univ. of Seoul, Seoul (Korea, Republic of)

2002-06-01

The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9{sup 9m}Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and {sup 99m}Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc-HMPAO brain SPECT

Energy Technology Data Exchange (ETDEWEB)

Juh, R. H.; Suh, T. S.; Chung, Y. A. [The Catholic Univ., of Korea, Seoul (Korea, Republic of)

2002-07-01

The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

Regional cerebral blood flow study with 123I-IMP in patients with degenerative dementia

International Nuclear Information System (INIS)

Ohnishi, T.; Hoshi, H.; Nagamachi, S.; Jinnouchi, S.; Futami, S.; Watanabe, K.; Mitsuyama, Y.

1991-01-01

Regional cerebral blood flow was evaluated by single-photon emission CT (SPECT) with 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) in 11 patients with dementia of the Alzheimer type, three patients with progressive dementia and motor neuron disease, and eight healthy control subjects. Regional blood flow measurements in the bilateral frontal, parietal association, and temporal cortices were lower in the Alzheimer dementia patients than in controls. Flow deficits in the parietal association cortex were demonstrated in all patients with Alzheimer-type dementia; these deficits were correlated with the severity of disease. Lateral hemispheric asymmetry was seen in nine of 11 patients with Alzheimer-type dementia. In all three patients with progressive dementia and motor neuron disease, flow deficits were demonstrated in the bilateral frontal and temporal cortices, but no flow deficits were seen in the parietal association cortex. Brain SPECT with 123I-IMP may be useful in the differential diagnosis and evaluation of the severity of degenerative dementia

Disodium cromoglycate, a mast-cell stabilizer, alters postradiation regional cerebral blood flow in primates

International Nuclear Information System (INIS)

Cockerham, L.G.; Doyle, T.F.; Pautler, E.L.; Hampton, J.D.

1986-01-01

Early transient incapacitation (ETI) is the complete cessation of performance during the first 30 min after radiation exposure, and performance decrement (PD) is a reduction in performance at the same time. Supralethal doses of radiation have been shown to produce a marked decrease in regional cerebral blood flow in primates concurrent with systemic hypotension and a dramatic release of mast-cell histamine. In an attempt to elucidate mechanisms underlying the radiation-induced ETI/PD phenomena and the postradiation decrease in cerebral blood flow, primates were given the mast-cell stabilizers disodium cromoglycate (DSCG) or BRL 22321 before exposure to 100 Gy whole-body gamma radiation. Hypothalamic and cortical blood flows were measured by hydrogen clearance, before and after radiation exposure. Systemic blood pressures were determined simultaneously. The data indicated that DSCG was successful in diminishing postradiation decrease in cerebral blood flow. Irradiated animals pretreated with DSCG, showed only a 10% decrease in hypothalamic blood flow 60 min postradiation, while untreated, irradiated animals showed a 57% decrease. The cortical blood flow of DSCG treated, irradiated animals showed a triphasic response, with a decrease of 38% at 10 min postradiation, then a rise to 1% below baseline at 20 min, followed by a fall to 42% below baseline by 50 min postradiation. In contrast, the untreated, irradiated animals showed a steady decrease in cortical blood flow to 79% below baseline by 50 min postradiation. There was no significant difference in blood-pressure response between the treated and untreated, irradiated animals. Systemic blood pressure showed a 60% decrease at 10 min postradiation, falling to a 71% decrease by 60 min

Regional cerebral blood flow in SPECT pattern in Parkinson's disease

International Nuclear Information System (INIS)

Lenart-Jankowska, D.; Junik, R.; Sowinski, J.; Gembicki, M.; Wender, M.

1997-01-01

The purpose of our work was to compare the regional cerebral blood flow (rCBF) in SPECT examination in Parkinson's disease with (17 cases) and without (7 cases) dementia and in various clinical stages of the disease. The patients underwent SPECT examination 5-40 min after intravenous application of HMPAO (Ceretec, Amersham) with 740 Mbq (20 mCi) pertechnate 99m Tc. SPECT was performed with a Siemens Diacam single-head rotating gamma camera coupled to a high resolution collimator and Icon computer system provided by the manufacturer. The results were defined in relative values of ROI in relation to cerebellum. Patients with Parkinson's disease showed hypoperfusion in cerebral lobes and in deep cerebral structures including the basal ganglia. Regional perfusion deficit in SPECT was seen with and without associated dementia and already in early stage of the disease. Parkinson's disease is provoked by the lesions of dopaminergic neurons of the central nervous system leading to domination of extrapyramidal symptoms. There are many indications that also the neurotransmitters associated with cognitive functions as acetylcholine demonstrate some abnormalities. However, only in some cases of Parkinson's disease dementia is the dominating symptom. Our results of regional cerebral blood flow testify that in Parkinson's disease the dysfunction of the central nervous system is more diffuse than has previously been suggested. (author)

Regional cerebral blood flow in various types of brain tumor. Effect of the space-occupying lesion on blood flow in brain tissue close to and remote from tumor site

DEFF Research Database (Denmark)

Kuroda, K; Skyhøj Olsen, T; Lassen, N A

1982-01-01

Regional cerebral blood flow (rCBF) was measured in 23 patients with brain tumors using the 133Xe intra-carotid injection method and a 254 channel gamma camera. The glioblastomas (4) and astrocytomas (4) all showed hyperemia in the tumor and tumor-near region. This was also seen in several...... meningiomas (4 of 7 cases) in which most of the tumor itself did not receive any isotope. Brain metastases (6) usually had a low flow in the tumor and tumor-near region. The glioblastomas tended to show markedly bending 133Xe wash-out curves pointing to pronounced heterogeneity of blood flow. Most of the flow...... maps, regardless of the tumor types, showed widespread abnormalities of rCBF not only in the tumor region but also in the region remote from the tumor. It is concluded that measurement of rCBF cannot yield accurate differential diagnostic information, but that the widespread derangement of the brain...

Quantitative Analysis of Regional Cerebral Blood Flow using 99mTc-HMPAO SPECT in Parkinson's Disease

International Nuclear Information System (INIS)

Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin; Lee, Myung Hae

1992-01-01

Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using 99m Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 ± 0.033 and 0.108 ± 0.062, respectively and PIA were -0.4 ± 0.7% and -0.7 ± 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

Regional cerebral blood flow measurement with intravenous [15O]water bolus and [18F]fluoromethane inhalation

International Nuclear Information System (INIS)

Herholz, K.; Pietrzyk, U.; Wienhard, K.; Hebold, I.; Pawlik, G.; Wagner, R.; Holthoff, V.; Klinkhammer, P.; Heiss, W.D.

1989-01-01

In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both [ 15 O]water and [ 18 F]fluoromethane as tracers. Cerebral blood flow was also determined according to the autoradiographic technique with a bolus injection of [ 15 O]water. There were reasonable overall correlations between dynamic [ 15 O]water and [ 18 F]fluoromethane values for cerebral blood flow (r = 0.82) and between dynamic and autoradiographic [ 15 O]water values for cerebral blood flow (r = 0.83). We found a close correspondence between abnormal pathologic findings and visually evaluated cerebral blood flow tomograms obtained with the two tracers. On average, dynamic [ 15 O]water cerebral blood flow was 6% lower than that measured with [ 18 F]fluoromethane. There also was a general trend toward a greater underestimation with [ 15 O]water in high-flow areas, particularly in hyperemic areas, probably due to incomplete first-pass extraction of [ 15 O]water. Underestimation was not detected in low-flow areas or in the cerebellum. Absolute cerebral blood flow values were less closely correlated between tracers and techniques than cerebral blood flow patterns. The variability of the relation between absolute flow values was probably caused by confounding effects of the variation in the circulatory delay time. The autoradiographic technique was most sensitive to this type error

New possibilities for quantitative measurements of regional cerebral blood flow with gold-195m

International Nuclear Information System (INIS)

Lindner, P.; Nickel, O.

1985-01-01

A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied to patients after stroke and to volunteers undergoing a mental stimulation exercise. The energy spectrum of gold-195m shows two strong photon peaks, one at an energy level of 68 keV and a second at an energy-level of 262 keV. The low energy peak is suitable for perfusion studies in lateral views of the hemispheres; no look-through effect is seen. The high energy level is good for studies in posterior-anterior positions. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results prove that, not only with freely diffusible indicators like xenon but also with nondiffusible indicators, it is possible to measure quantitatively cerebral blood flow patterns

Autoradiographic study of the regional distribution of gastric blood flow in portal hypertensive rats

International Nuclear Information System (INIS)

Geraghty, J.G.; Angerson, W.J.; Carter, D.C.

1989-01-01

This study measures regional gastric blood flow in portal hypertensive rats at three separate periods after portal vein ligation using quantitative autoradiography with 14C-labeled iodoantipyrine. The level of corpus mucosal blood flow was significantly reduced in 3-day portal vein-ligated animals compared with sham-operated control animals (30.4 +/- 2.3 vs. 47.1 +/- 5.6 ml/100 g.min). There was no significant difference in corpus mucosal blood flow between portal vein-ligated and sham-operated animals at 7- and 28-day periods, although the level of perfusion was higher in the 28-day portal vein-ligated group. There was no significant difference in antral mucosal or muscle blood flow between portal hypertensive and control animals at any of the study periods. We conclude that the acute period after portal vein ligation is associated with a reduced corpus mucosal microcirculation but that this effect is not sustained in portal hypertensive animals studied at later intervals after portal vein ligation

Regional cerebral blood flow changes associated with clitorally induced orgasm in healthy women

NARCIS (Netherlands)

Georgiadis, Janniko R.; Kortekaas, Rudie; Kuipers, Rutger; Nieuwenburg, Arie; Pruim, Jan; Reinders, A. A. T. Simone; Holstege, Gert

2006-01-01

There is a severe lack of knowledge regarding the brain regions involved in human sexual performance in general, and female orgasm in particular. We used [(15)O]-H(2)O positron emission tomography to measure regional cerebral blood flow (rCBF) in 12 healthy women during a nonsexual resting state,

Interactive handling of regional cerebral blood flow data using a macrolanguage

International Nuclear Information System (INIS)

Sveinsdottir, E.; Schomacker, T.; Lassen, N.A.

1976-01-01

A general image handling software system has been developed for on-line collection, processing and display of gamma camera images (IMAGE system). The most distinguishable feature of the system is the ability for the user to interactively specify sequences, called macros, of basic functions to be performed. Information about a specified sequence is retained in the system, thus enabling new sequences or macros to be defined using already specified sequences. Facilities for parameter setting and parameter transfer between functions, as well as facilities for repetition of a function, are included. Finally, functions, be it basic or macro, can be specified to be iteratively activated using a physiological trigger signal as f.ex. the ECG. In addition, a special program system was developed for handling the dynamic data, from Xenon-133 studies of regional cerebral blood flow (CBF system). Parametric or functional images derived from the CBF system and depicting estimates of regional cerebral blood flow, relative weights of grey matter or other parameters can after computation be handled in the IMAGE system

Cerebellar blood flow in methylmercury poisoning (Minamata disease)

Energy Technology Data Exchange (ETDEWEB)

Itoh, K.; Korogi, Y.; Tomiguchi, S.; Takahashi, M. [Dept. of Radiology, Kumamoto University School of Medicine (Japan); Okajima, T. [Dept. of Neurology, Johnan Hospital, Maihara, Johnan-mochi (Japan); Sato, H. [Dept. of Neurology, Minamata City General Hospital and Medical Centre (Japan)

2001-04-01

We looked at regional cerebellar blood flow in patients with Minamata disease (MD) using technetium-99 m ethyl cysteinate dimer (99m-Tc-ECD). We carried out single-photon emission computed tomography (SPECT) on 15 patients with MD (eight men, seven women, aged 51-78 years, mean 70.5 years) and 11 control subjects (eight men, three women, aged 62-80 years, mean 72.5 years). Regional blood flow was measured in the superior, middle, and inferior portions of the cerebellar hemispheres, and the frontal, temporal and occipital cerebral lobes. The degree of cerebellar atrophy was assessed on MRI. There were significant differences in regional blood flow in all parts of the cerebellum between patients and control, but no significant decrease was observed in the cerebrum. Blood flow was lower in the inferior cerebellum than in the other parts. Even in patients without cerebellar atrophy, flow was significantly decreased regional blood flow in the inferior part. (orig.)

Cerebellar blood flow in methylmercury poisoning (Minamata disease)

International Nuclear Information System (INIS)

Itoh, K.; Korogi, Y.; Tomiguchi, S.; Takahashi, M.; Okajima, T.; Sato, H.

2001-01-01

We looked at regional cerebellar blood flow in patients with Minamata disease (MD) using technetium-99 m ethyl cysteinate dimer (99m-Tc-ECD). We carried out single-photon emission computed tomography (SPECT) on 15 patients with MD (eight men, seven women, aged 51-78 years, mean 70.5 years) and 11 control subjects (eight men, three women, aged 62-80 years, mean 72.5 years). Regional blood flow was measured in the superior, middle, and inferior portions of the cerebellar hemispheres, and the frontal, temporal and occipital cerebral lobes. The degree of cerebellar atrophy was assessed on MRI. There were significant differences in regional blood flow in all parts of the cerebellum between patients and control, but no significant decrease was observed in the cerebrum. Blood flow was lower in the inferior cerebellum than in the other parts. Even in patients without cerebellar atrophy, flow was significantly decreased regional blood flow in the inferior part. (orig.)

Alterations of Regional Cerebral Blood Flow in Major Depressive Disorder

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Hyoung; Chung, Yong An; Seo, Ye Young; Yoo, Ik Dong; Na, Sae Jung; Jung, Hyun Suk; Kim, Ki Jun [College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

2009-04-15

The authors analyzed how the regional cerebral blood flow (rCBF) findings of patients with major depression differ from the normal control, and our results were compared to previous reports. Twelve patients fulfilling DSM-IV criteria for major depression who were off all psychotropic medications for > 4 weeks (male: 7, female: 5, age range: 19approx52 years, average age: 29.3+-9.9 years) and 14 normal volunteers (male: 8, female: 6, age range: 19approx53 years, average age: 31.4+-9.2 years) were recruited. Images of brain perfusion SPECT were obtained using Tc-99m ECD and patterns of the rCBF were compared between patients with major depression and the healthy control subjects. The patients with major depression showed increase of the r-CBF in right lingual gyrus, right fusiform gyrus, left lingual gyrus, left precuneus, and left superior temporal gyrus, and showed decrease of r-CBF in right pons, left medial frontal gyrus, cingulate gyrus of left limbic lobe, cingulate gyrus of right frontal lobe, and cingulate gyrus of right limbic lobe compared to the normal control. The Tc-99m ECD brain perfusion SPECT findings in our study did not differ from the previously reported regional cerebral blood flow pattern of patients with major depression. Especially, decreased rCBF pattern typical to major depression patients in the right pons, left medial frontal gyrus, and cingulate regions was clearly demonstrated

Alterations of Regional Cerebral Blood Flow in Major Depressive Disorder

International Nuclear Information System (INIS)

Lee, Won Hyoung; Chung, Yong An; Seo, Ye Young; Yoo, Ik Dong; Na, Sae Jung; Jung, Hyun Suk; Kim, Ki Jun

2009-01-01

The authors analyzed how the regional cerebral blood flow (rCBF) findings of patients with major depression differ from the normal control, and our results were compared to previous reports. Twelve patients fulfilling DSM-IV criteria for major depression who were off all psychotropic medications for > 4 weeks (male: 7, female: 5, age range: 19∼52 years, average age: 29.3±9.9 years) and 14 normal volunteers (male: 8, female: 6, age range: 19∼53 years, average age: 31.4±9.2 years) were recruited. Images of brain perfusion SPECT were obtained using Tc-99m ECD and patterns of the rCBF were compared between patients with major depression and the healthy control subjects. The patients with major depression showed increase of the r-CBF in right lingual gyrus, right fusiform gyrus, left lingual gyrus, left precuneus, and left superior temporal gyrus, and showed decrease of r-CBF in right pons, left medial frontal gyrus, cingulate gyrus of left limbic lobe, cingulate gyrus of right frontal lobe, and cingulate gyrus of right limbic lobe compared to the normal control. The Tc-99m ECD brain perfusion SPECT findings in our study did not differ from the previously reported regional cerebral blood flow pattern of patients with major depression. Especially, decreased rCBF pattern typical to major depression patients in the right pons, left medial frontal gyrus, and cingulate regions was clearly demonstrated

Single-photon tomographic determination of regional cerebral blood flow in psychiatric disorders

International Nuclear Information System (INIS)

Devous, M.D. Sr.; Rush, A.J.; Schlesser, M.A.; Debus, J.; Raese, J.D.; Chehabi, H.H.; Bonte, F.J.

1984-01-01

Regional cerebral blood flow (rCBF) was measured by single-photon emission computed tomography (SPECT) of 133-Xe washout in 29 normal volunteers, 22 unipolar endogenous depressives (UPE), 9 unipolar nonendogenous depressives (UPNE), 13 bipolar depressed patients (BPD), and 14 schizophrenic patients (SCHZ). RCBF was measured 2 and 6 cm above and parallel to the cantho-meatal line and quantitated in 14 gray matter regions. Most subjects were drug-free for 4-14 days. Diagnoses were made by experienced clinicians employing the Research Diagnostic Criteria, the Hamilton Rating Scale, and the dexamethasone suppression test. SCHZ were rated with the Brief Psychiatric Rating Scale. UPE had reduced flow compared to normals in the right parietal and temporal lobes and a nonsignificant trend toward left temporal flow reductions. UPNE were not different from normal or other patient groups. BPD had significant flow elevations in the left hemisphere relative to normal, and in both hemispheres relative to UPE. SCHZ were not significantly different from normal or other patient groups. Anterior-posterior flow shifts were evaluated by subtracting parietal or temporal flows from frontal flows. SCHZ demonstrated a greater posterior shift (lower relative frontal lobe flow) in comparison to both UPE and UPNE. The most significant regional flow abnormalities were observed as frontal flow reductions in individual SCHZ, although these were not significant in the whole group in comparison to normal

Bone blood flow after spinal paralysis in the rat

International Nuclear Information System (INIS)

Takahashi, H.; Yamamuro, T.; Okumura, H.; Kasai, R.; Tada, K.

1990-01-01

The goal of this study was to investigate the acute and chronic effects of paralysis induced by spinal cord section or sciatic neurotomy on bone blood flow in the rat. Regional bone blood flow was measured in the early stage with the hydrogen washout technique and the change of whole bone blood flow was measured in the early and the late stages with the radioactive microsphere technique. Four to 6 h after cordotomy at the level of the 13th thoracic vertebra, the regional bone blood flow in the denervated tibia increased significantly (p less than 0.01). After hemicordotomy with rhizotomy at the same level, the regional bone blood flow in the denervated tibia increased significantly (p less than 0.05) 6 h postoperatively. The whole bone blood flow in the denervated tibia had also increased significantly (p less than 0.05) at 6 h and at 4 and 12 weeks postoperatively. After sciatic neurotomy, the regional and the whole bone blood flow in the paralytic tibia did not change significantly. The present study demonstrated that monoplegic paralysis caused an increase in bone blood flow in the denervated hind limb from a very early stage. It was suggested that the spinal nervous system contributed to the control of bone blood flow

New possibilities for quantitative measurements of regional cerebral blood flow with Au-195 m

International Nuclear Information System (INIS)

Lindner, P.; Nickel, O.

1984-01-01

A previously reported theory for quantitative cerebral blood flow measurement for nondiffusible radiotracers has been applied on patients after stroke and an volunteers undergoing a mental stimulation exercise. Quantitative measurements of cerebral blood flow patterns not only in p-a. but also in lateral views of the brain are possible by the use of the recently developed generator for the short lived (30 sec) isotope Au-195 m. The energy spectrum of the eluate of the generator shows two strong photon peaks, one at an energy level of 68 KeV and a second at an energy-level of 262 KeV. The low energy peak is suitable for perfusion studies in lateral views of the hemispheres, no ''look through'' effect is seen. The high energy level is good for studies in p-a-positions. The studies last less than 1 minute and can be repeated after 3 minutes. Parametric images for quantitative regional cerebral blood flow can be generated. The area of occluded vessels in the case of stroke can be detected. Quantitative activation patterns of cerebral blood flow during mental stimulation can be generated. The results prove that not only with freely diffusible indicators like Xenon but also with nondiffusible indicators it is possible to measure quantitatively cerebral blood flow patterns. (orig.)

[Effects of therapeutic complexes including balneoradonokinesitherapy, electromyostimulation and low-frequency magnetotherapy on regional blood flow in patients with postrraumatic gonarthritis].

Science.gov (United States)

Raspopova, E A; Udartsev, E Iu

2006-01-01

Balneoradonokinesitherapy alone and its combination with electrostimulation and low-frequency magnetotherapy were used for the treatment of regional blood flow disorders in 76 patients with posttraumatic gonarthritis. Balneoradonokinesitherapy in combination with electromyostimulation improved blood circulation. When low-frequency magnetotherapy was added to the latter complex, the regress of regional blood flow disorders of a damaged extremity was most significant.

Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

International Nuclear Information System (INIS)

Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

1983-01-01

Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H 2 O, labeled with the positron-emitting isotope, 15 O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement

Detection of viable myocardium in canine model with myocardial ischemia and ischemia-reperfusion by 125I-BMIPP: relation to regional blood flow

International Nuclear Information System (INIS)

Huang Gang; Zhao Huiyang; Shen Xuedong; Li Qing; Yuan Jimin; Zhu Cuiying

1999-01-01

Objective: The effects of BMIPP (β-methyl-iodophenyl pentadecanoic acid) on detecting viable myocardium and the relation between regional blood flow and the uptake of BMIPP were evaluated in canine model of myocardial ischemia and ischemia-reperfusion. Methods: 12 open-chest dogs under anesthesia were divided into two groups. Group I (ischemia group) had left circumflex coronary arterial occlusion for 2 h and group II (ischemia-reperfusion group) was occluded for 1 h and followed by 2 h reperfusion. Myocardial blood flow was measured with 99 Tc m -microspheres. 30 min after intravenous injection of 125 I-BMIPP and 99 Tc m -microspheres, the heart was excised rapidly and stained with Evans blue and NBT. Tissue samples (divided into approximately 1 g) of left ventricle were obtained, weighed and counted for 125 I and 99 Tc m . Regional blood flow and the uptake of BMIPP were expressed as percentages of average values in non-ischemic myocardium (two to three tissue samples) from the normal myocardium. Results: In ischemic myocardium (NBT positive samples), the uptake of BMIPP was relatively higher compared with regional blood flow [(67 +- 23)% vs (42 +- 19)%, P 0.05]. In ischemia-reperfusion group, regional blood flow was increased in ischemic and necrotic tissues, but the uptake of BMIPP was not enhanced with the increasing blood flow. Conclusions: BMIPP uptake seems to provide metabolic information independent of regional blood flow. The mismatching between regional blood flow and BMIPP uptake may indicate myocardial viability in the regions of hypoperfusion and the uptake of BMIPP in ischemic myocardium was related to existence of cellular metabolism

Regional cerebral blood flow in normal pressure hydrocephalus: diagnostic and prognostic aspects

International Nuclear Information System (INIS)

Larsson, A.; Bergh, A.C.; Bilting, M.; Aerlig, AA.; Jacobsson, L.; Stephensen, H.; Wikkelsoe, C.

1994-01-01

Relative regional cerebral blood flow (rrCBF) was measured by SPET using 99m Tc-HMPAO as flow tracer, in 23 patients with normal pressure hydrocephalus (NPH). 1000 MBq 99m Tc-HMPAO was given intravenously and the rrCBF calculated as regional/cerebellar count level ratios. The patients were examined before and 3-12 months after ventriculoperitoneal shunt surgery. rrCBF was also determined in ten healthy aged matched volunteers who served as controls. The NPH patients had decreased rrCBF in the hippocampal regions and in the frontal and parietal white matter as compared to the controls. The frontal/parietal rrCBF ratio correlated with both psychiatric disability and the preoperative degree of incontinence. Decreased flow in frontal white matter, frontoparietal and hippocampal grey matter and a low frontalparietal grey matter flow ratio preoperatively correlated with improvement in both Mini Mental State score and psychiatric disability after shunt surgery. After shunt surgery the rrCBF increased in the mesencephalon, frontal grey and white matter, parietal white matter and hippocampus. The flow increase in hippocampal regions and frontal white matter correlated with improvement in psychiatric symptomatology. The results of this study regarding the frontal and hippocampal rrCBF patterns, and the clinical correlation, support the hypothesis that CBF changes in these regions are of patohphysiological and prognostic importance in NPH. (orig./MG)

Regional cerebral blood flow distribution in newly diagnosed schizophrenia and schizophreniform disorder

DEFF Research Database (Denmark)

Rubin, P; Holm, S; Madsen, P L

1994-01-01

Regional cerebral blood flow distribution (rCBF) in 24 first admissions with schizophrenia or schizophreniform disorder and in 17 healthy volunteers was examined. Single photon emission computed tomography with a brain-retained tracer, technetium-99m-d,l-hexamethyl-propylene amine oxime, was used...... interrelationship in schizophrenia and schizophreniform disorder....

Quantitative Analysis of Regional Cerebral Blood Flow using {sup 99m}Tc-HMPAO SPECT in Parkinson's Disease

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Chul; Bae, Sang Kyun; Chung, June Key; Koh, Chang Soon; Roh, Jae Kyu; Myung, Ho Jin [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Myung Hae [Asan Medical Center, Seoul (Korea, Republic of)

1992-07-15

Regional cerebral blood flow were measured in 10 patients with Parkinson's disease and 12 normal persons using {sup 99m}Tc-HMPAO SPECT. Reconstructed images were interpreted qualitatively and were compared with those findings of CT. For the quantitative analysis, six pairs of region of interest matched with the perfusion territories of large cerebral arteries and cerebellar hemisphere were determined. From the count values, indices showing the degree of asymmetry between right and left cerebral or cerebellar hemisphere, cerebral asymmetry index (ASI) and percent index of cerebellar asymmetry (PIA), and an index showing change of each region, region to cerebellum ratio (RCR) were obtained. ASI of normal persons and patients were 0.082 +- 0.033 and 0.108 +- 0.062, respectively and PIA were -0.4 +- 0.7% and -0.7 +- 1.0%, respectively, which showed no statistically significant difference between normal persons and patients. Among 10 RCR's, those of both regions of basal ganglia and both regions of anterior cerebral artery were significantly reduced. We concluded that the most significant reduction of regional cerebral blood flow in patients with Parkinson's disease was observed in the regions of basal ganglia and in the regions of anterior cerebral artery, and the degree of change in hemispheric blood flow was similar in both hemisphere.

Simultaneous estimates of regional myocardial blood flow and metabolism by the developing chick heart using [201]thallium and [14C] 2-deoxyglucose autoradiography

International Nuclear Information System (INIS)

Kostreva, D.R.; Wood, J.D.

1990-01-01

Little is known about regional myocardial blood flow and metabolism in the developing heart. Simultaneous estimates of regional myocardial blood flow and glucose metabolism have been made in the adult rat by Yonekura et al using [ 201 ] Thallium (THAL) and [ 14 C]2-deoxyglucose (DG) autoradiography. Since glucose is the primary cardiac metabolic substrate during development, glucose utilization is also an estimate of myocardial metabolism. Examination and comparison of the THAL and DG autoradiographs revealed that there is an uncoupling of blood flow and metabolism in the developing chick heart. Areas of the heart which had marked glucose utilization did not always have marked blood flow. Regions of the heart which had marked blood flow but very little glucose utilization were the interventricular septum and the apex. One explanation for this disparity is that although blood flow may be established in these regions, normal cardiac function requiring significant substrate utilization may not be fully developed

Changes in regional blood flow of normal and tumor tissues following hyperthermia and combined X-ray irradiation

International Nuclear Information System (INIS)

Suga, Kazuyoshi

1986-01-01

Hyperthermia and X-ray irradiation were given to Ehrlich tumors, which were induced in the ventrum of the right hind foot of ICR mice, and to the normal tissues. Their effects on regional blood flow were examined using Xe-133 local clearance method. Blood flow of the normal tissues remained unchanged by heating at 41 deg C for 30 minutes, and increased by heating at 43 deg C and 45 deg C for 30 minutes. On the contrary, blood flow of the tumors decreased with an increase in temperature. When hypertermia (43 deg C for 30 minutes) was combined with irradiation of 30 Gy, decrease in blood flow of the tumors was greater than the normal tissues at 24 hours. Blood flow of the tumors depended on tumor size. The decreased amount of blood flow by hyperthermia was more for tumors > 250 mm 3 than tumors 3 . Blood flow ratios of tumor to normal tissues were also smaller in tumors > 250 mm 3 than tumors 3 . In the case of tumors 3 , blood flow tended to return to normal at 3 hr after heating at 43 deg C for 30 min. However, this was not seen in tumors > 250 mm 3 . (Namekawa, K.)

Left-right cortical asymmetries of regional cerebral blood flow during listening to words

DEFF Research Database (Denmark)

Nishizawa, Y; Olsen, T S; Larsen, B

1982-01-01

1. Regional cerebral blood flow (rCBF) was measured during rest and during listening to simple words. The xenon-133 intracarotid technique was used and results were obtained from 254 regions of seven right hemispheres and seven left hemispheres. The measurements were performed just after carotid...... of the entire hemisphere. The focal rCBF increases were localized to the superior part of the temporal regions, the prefrontal regions, the frontal eye fields, and the orbitofrontal regions. Significant asymmetries were found in particular in the superior temporal region with the left side showing a more...

Evaluation of nonradioactive, colored microspheres for measurement of regional myocardial blood flow in dogs

International Nuclear Information System (INIS)

Hale, S.L.; Alker, K.J.; Kloner, R.A.

1988-01-01

Measurement of regional myocardial blood flow (RMBF) is crucial in experimental studies of myocardial ischemia and reperfusion in dogs. The standard measurement technique uses radioactive microspheres; however, not all institutions are able to dispose of radioactive waste and therefore cannot make use of this method. We tested a new, nonradioactive microsphere, labeled with colors instead of nuclides. Simultaneous blood flow measurements with two nuclide-labeled and two colored microspheres were performed after coronary occlusion in dogs. Both techniques show a within-method correlation of r greater than 0.98. Duplicate variability for paired RMBF values in 80 samples was 8.7 +/- 0.1% when computed with radioactive microspheres and 13.2 +/- 1.8% when computed with colored microspheres. There was a good correlation in the measurement of RMBF between the radioactive- and colored-microsphere methods (r = 0.98). The best-fitting linear regression line was expressed by the formula: Colored-microsphere RMBF = 1.11 (radioactive-microsphere RMBF)-0.02. When measured by colored microspheres, RMBF was approximately 8% higher than when computed with radioactive microspheres for blood flow values of 0-2 ml/min/g. When blood flow was increased pharmacologically to levels of 2-7.5 ml/min/g, colored microspheres yielded blood flow values 39% higher than the values computed by radioactive microspheres. We conclude that the nonradioactive, colored-microsphere method correlates with the radioactive technique, but at high flows, it yields values greater than those obtained with radioactive microspheres

Regional cerebral blood flow in neuropediatrics

International Nuclear Information System (INIS)

Junik, R.

2001-01-01

Single photon emission computed tomography can effectively and non-invasively measure regional blood flow. Mostly used 99mTc-HMPAO is a safe brain imaging agent for pediatric applications. The radiation dose is acceptable. Knowledge of the normal rCBF pattern, including normal asymmetries and variations due to age, is necessary prerequisite for the evaluation and reporting of the results of 99mTc-HMPAO brain SPECT studies in clinical practice. The interpretation of he rCBF study in a child requires knowledge of normal brain maturation. The aim of the present review is to focus on the contribution to clinical developmental neurology of SPECT The clinical use of SPECT in developmental neurology are epilepsy, brain death, acute neurological loss including stroke, language disorders, cerebral palsy, high-risk neonates, hypertension due to renovascular disease, traumatic brain injury, migraine, anorexia nervosa, autism, Gilles de la Tourette syndrome, attention deficit disorder-hyperactivity, and monitoring therapy. Sedation is not routinely used, rather each child is evaluated. However, drug sedation is mandatory in some uncooperative children. (author)

Transcatheter embolization for high blood flow vascular malformations of oral maxillofacial region

International Nuclear Information System (INIS)

Sun Zengtao; Liu Zuoqin; Li Jijun; Tang Jun; Shang Jianqiang; Chen Jie

2007-01-01

Objective: To explore the treatment and efficiency of high blood flow vascular malformations of oral maxillofacial region with super-selective arterial embolization. Methods: 18 cases underwent angiography of the head and neck before treatment and then followed by super-selective catheterization with microcatheter to embolize the feeding vessels of the vascular malformations with PVA. 8 cases underwent surgical excision within 72 hours after the embolization and the other 10 cases passed through the arterial radical emboliztion treatment. Results: Technical success ratio reached 100% with no complications causing skin necrosis or incorrect arterial embolization else where in the skull. All 8 cases undergone preoperative embolization showed obviously less bleeding, easier removal of the mass and reduction of operation time. 10 cases with radical arterial embolization manifested reduction of swelling and improvement of organ function within 1 to 24 months after the procedure. 5 patients were cured with only once operation, 4 cases with twice operation and 1 with the thrice. Conclusions: Aterial embolization is a safe and effective method in the treatment of high blood flow vascular malformations of oral maxillofacial region. (authors)

Measurement of regional cerebral blood flow by xenon-enhanced computed tomography

International Nuclear Information System (INIS)

Nakagomi, Tadayoshi; Yoshimasu, Norio; Kim, Shi-in; Takano, Koichi; Segawa, Hiromu.

1982-01-01

Serial CT scanning was carried out during and after inhalation of 50% non-radioactive xenon in humans. Our results of this research was as follows; 1) In normal subjects, blood flow in gray matter was 82 +- 11 and that in white matter 24 +- 5 ml/100 gm/min. 2) The blood flow of the brain tumors was close to that of gray matter, whereas blood flow of edematous white matter surrounding the tumor was decreased. 3) The blood flow in cerebral infarctions was always decreased. Effect of STA-MCA bypass was also evaluated. 4) In cerebral arterio-venous malformations, the blood flow in the white matter surrounding nidus was not decreased. This method appeared to have several advantages over conventional isotope method and to provide useful clinical and research informations. (author)

Regional cerebral blood flow in mood disorders. I. Comparison of major depressives and normal controls at rest

International Nuclear Information System (INIS)

Sackeim, H.A.; Prohovnik, I.; Moeller, J.R.; Brown, R.P.; Apter, S.; Prudic, J.; Devanand, D.P.; Mukherjee, S.

1990-01-01

We measured regional cerebral blood flow with the xenon 133 inhalation technique in 41 patients with major depressive disorder and 40 matched, normal controls during an eyes-closed, resting condition. The depressed group had a marked reduction in global cortical blood flow. To examine topographic abnormalities, traditional multivariate analyses were applied, as well as a new scaled subprofile model developed to identify abnormal functional neural networks in clinical samples. Both approaches indicated that the depressed sample had an abnormality in topographic distribution of blood flow, in addition to the global deficit. The scaled subprofile model identified the topographic abnormality as being due to flow reduction in the depressed patients in selective frontal, central, superior temporal, and anterior parietal regions. This pattern may reflect dysfunction in the parallel distributed cortical network involving frontal and temporoparietal polymodal association areas. The extent of this topographic abnormality, as revealed by the scaled subprofile model, was associated with both patient age and severity of depressive symptoms

Renal blood flow in sepsis: a complex issue

OpenAIRE

Molitoris, Bruce A

2005-01-01

The clinical complexity of sepsis and the regional variability in renal blood flow present a difficult challenge for the clinician or investigator in understanding the role and clinical importance of reduced blood flow in the pathophysiology of sepsis-induced acute renal failure. Understanding the role of regional microvasculature flow and interactions between endothelium and white blood cells in the local delivery of oxygen and substrates is of critical importance. Therefore, measuring total...

Regional cerebral blood flow changes associated with focal electrically administered seizure therapy (FEAST).

Science.gov (United States)

Chahine, George; Short, Baron; Spicer, Ken; Schmidt, Matthew; Burns, Carol; Atoui, Mia; George, Mark S; Sackeim, Harold A; Nahas, Ziad

2014-01-01

Use of electroconvulsive therapy (ECT) is limited by cognitive disturbance. Focal electrically-administered seizure therapy (FEAST) is designed to initiate focal seizures in the prefrontal cortex. To date, no studies have documented the effects of FEAST on regional cerebral blood flow (rCBF). A 72 year old depressed man underwent three single photon emission computed tomography (SPECT) scans to capture the onset and resolution of seizures triggered with right unilateral FEAST. We used Bioimage Suite for within-subject statistical analyses of perfusion differences ictally and post-ictally compared with the baseline scan. Early ictal increases in regional cerebral blood flow (rCBF) were limited to the right prefrontal cortex. Post-ictally, perfusion was reduced in bilateral frontal and occipital cortices and increased in left motor and precuneus cortex. FEAST appears to triggers focal onsets of seizure activity in the right prefrontal cortex with subsequent generalization. Future studies are needed on a larger sample. Copyright © 2014 Elsevier Inc. All rights reserved.

Exercise increases blood flow to locomotor, vestibular, cardiorespiratory and visual regions of the brain in miniature swine

Science.gov (United States)

Delp, M. D.; Armstrong, R. B.; Godfrey, D. A.; Laughlin, M. H.; Ross, C. D.; Wilkerson, M. K.

2001-01-01

1. The purpose of these experiments was to use radiolabelled microspheres to measure blood flow distribution within the brain, and in particular to areas associated with motor function, maintenance of equilibrium, cardiorespiratory control, vision, hearing and smell, at rest and during exercise in miniature swine. Exercise consisted of steady-state treadmill running at intensities eliciting 70 and 100 % maximal oxygen consumption (V(O(2),max)). 2. Mean arterial pressure was elevated by 17 and 26 % above that at rest during exercise at 70 and 100 % V(O(2),max), respectively. 3. Mean brain blood flow increased 24 and 25 % at 70 and 100 % V(O(2),max), respectively. Blood flow was not locally elevated to cortical regions associated with motor and somatosensory functions during exercise, but was increased to several subcortical areas that are involved in the control of locomotion. 4. Exercise elevated perfusion and diminished vascular resistance in several regions of the brain related to the maintenance of equilibrium (vestibular nuclear area, cerebellar ventral vermis and floccular lobe), cardiorespiratory control (medulla and pons), and vision (dorsal occipital cortex, superior colliculi and lateral geniculate body). Conversely, blood flow to regions related to hearing (cochlear nuclei, inferior colliculi and temporal cortex) and smell (olfactory bulbs and rhinencephalon) were unaltered by exercise and associated with increases in vascular resistance. 5. The data indicate that blood flow increases as a function of exercise intensity to several areas of the brain associated with integrating sensory input and motor output (anterior and dorsal cerebellar vermis) and the maintenance of equilibrium (vestibular nuclei). Additionally, there was an intensity-dependent decrease of vascular resistance in the dorsal cerebellar vermis.

Cognitive profiles and regional cerebral blood flow patterns in dementia of the Alzheimer type

DEFF Research Database (Denmark)

Waldemar, G; Bruhn, P; Schmidt, E

1994-01-01

Individual cognitive profiles and correlations between cognitive functions and regional cerebral blood flow (rCBF) were analyzed in 20 consecutive patients with a clinical diagnosis of probable Alzheimer's disease (AD). CBF was measured with high resolution single photon emission computed...

Regional blood flow distribution and oxygen metabolism during mesenteric ischemia and congestion.

Science.gov (United States)

Cruz, Ruy J; Garrido, Alejandra G; Ribeiro, Cristiane M F; Harada, Tomoyuki; Rocha-e-Silva, Mauricio

2010-06-01

Acute mesenteric ischemia is a potentially fatal vascular emergency with mortality rates ranging between 60% and 80%. Several studies have extensively examined the hemodynamic and metabolic effects of superior mesenteric artery occlusion. On the other hand, the cardiocirculatory derangement and the tissue damage induced by intestinal outflow obstruction have not been investigated systematically. For these reasons we decided to assess the initial impact of venous mesenteric occlusion on intestinal blood flow distribution, and correlate these findings with other systemic and regional perfusion markers. Fourteen mongrel dogs were subjected to 45 min of superior mesenteric artery (SMAO) or vein occlusion (SMVO), and observed for 120 min after reperfusion. Systemic hemodynamics were evaluated using Swan-Ganz and arterial catheters. Regional blood flow (ultrasonic flow probes), intestinal O(2)-derived variables, and mesenteric-arterial and tonometric-arterial pCO(2) gradients (D(mv-a)pCO(2) and D(t-a)pCO(2)) were also calculated. SMVO was associated with hypotension and low cardiac output. A significant increase in the regional pCO(2) gradients was also observed in both groups during the ischemic period. After reperfusion, a progressive reduction in D(mv-a)pCO(2) occurred in the SMVO group; however, no improvement in D(t-a)pCO(2) was observed. The histopathologic injury scores were 2.7 +/- 0.5 and 4.8 +/- 0.2 for SMAO and SMVO, respectively. SMV occlusion promoted early and significant hemodynamic and metabolic derangement at systemic and regional levels. Additionally, systemic pCO(2) gradient is not a reliable parameter to evaluate the local intestinal oxygenation. Finally, the D(t-a)pCO(2) correlates with histologic changes during intestinal congestion or ischemia. However, minor histologic changes cannot be detected using this methodology. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Effect of axillary blockade on regional cerebral blood flow during static handgrip

DEFF Research Database (Denmark)

Friedman, D B; Friberg, L; Mitchell, J H

1991-01-01

Regional cerebral blood flow (rCBF) was determined at rest and during static handgrip before and after regional blockade with lidocaine. A fast rotating single photon emission computer tomograph system with 133Xe inhalation was used at orbitomeatal plane (OM) +2.5 and +6.5 cm in eight subjects. M...... static handgrip, there was no increase in rCBF after partial sensory and motor blockade. Thus bilateral activation occurs in the premotor and motor sensory cortex during static handgrip, and this activation requires neural feedback from the contracting muscles....

Effect of regional heating on the liver blood flow in rats

International Nuclear Information System (INIS)

Nakajima, T.; Song, C.W.; Osborn, J.L.; Rhee, J.G.; Levitt, S.H.

1987-01-01

The authors measured the blood flow in the liver of rats heated with a radio frequency capacitive heating device. The blood flow through the hepatic artery, as measured with the radioactive microsphere method, was 0.21 ml/min/gm; it increased by 13% and 16% when heated for 15 minutes at 41 0 C and 43 0 C, respectively. The portal vein blood flow was 1.09 ml/min/gm and decreased by 12% and 20% on heating for 15 minutes at 41 0 C and 43 0 C, respectively. The total liver blood flow, therefore, decreased by 11% at 41 0 C and by 14% at 43 0 C from the control value of 1.30 ml/min/gm

Age and regional cerebral blood flow at rest and during cognitive activity

International Nuclear Information System (INIS)

Gur, R.C.; Gur, R.E.; Obrist, W.D.; Skolnick, B.E.; Reivich, M.

1987-01-01

The relationship between age and regional cerebral blood flow (rCBF) activation for cognitive tasks was investigated with the xenon (Xe 133) inhalation technique. The sample consisted of 55 healthy subjects, ranging in age from 18 to 72 years, who were studied during rest and during the performance of verbal analogy and spatial orientation tasks. The dependent measures were indexes of gray-matter rCBF and average rCBF (gray and white matter) as well as the percentage of gray-matter tissue. Advanced age was associated with reduced flow, particularly pronounced in anterior regions. However, the extent and pattern of rCBF changes during cognition was unaffected by age. For the percentage of gray matter, there was a specific reduction in anterior regions of the left hemisphere. The findings suggest the utility of this research paradigm for investigating neural underpinnings of the effects of dementia on cognitive functioning, relative to the effects of normal aging

Regional cerebral blood flow changes related to affective speech presentation in persistent vegetative state

NARCIS (Netherlands)

deJong, BM; Willemsen, ATM; Paans, AMJ

A story told by his mother was presented on tape to a trauma patient in persistent vegetative state (PVS). During auditory presentation, measurements of regional cerebral blood flow (rCBF) were performed by means of positron emission tomography (PET). Changes in rCBF related to this stimulus

Regional cerebral blood flow in psychiatry: The resting and activated brains of schizophrenic patients

International Nuclear Information System (INIS)

Gur, R.E.

1984-01-01

The investigation of regional brain functioning in schizophrenia has been based on behavioral techniques. Although results are sometimes inconsistent, the behavioral observations suggest left hemispheric dysfunction and left hemispheric overreaction. Recent developments in neuroimaging technology make possible major refinements in assessing regional brain function. Both anatomical and physiological information now be used to study regional brain development in psychiatric disorders. This chapter describes the application of one method - the xenon-133 technique for measuring regional cerebral blood flow (rCBF) - in studying the resting and activated brains of schizoprenic patients

Regional cerebral blood flow and brain atrophy in senile dementia of Alzheimer type (SDAT)

International Nuclear Information System (INIS)

Okada, Kazunori; Kobayashi, Shoutai; Yamaguchi, Shuhei; Kitani, Mituhiro; Tsunematsu, Tokugoro

1987-01-01

To investigate the relationship between the reduction of cerebal blood flow and brain atrophy in SDAT, these were measured in 13 cases of senile dementia of Alzheimer type, and compared to 15 cases of multi-infarct Dementia, 39 cases of lacunar infarction without dementia (non-demented CVD group) and 69 cases of aged normal control. Brain atrophy was evaluated by two-dimensional method on CT film by digitizer and regional cerebral blood flow (rCBF) was measured by 133 Xe inhalation method. The degree of brain atrophy in SDAT was almost similar of that of MID. But it was more severe than that of non-demented group. MID showed the lowest rCBF among these groups. SDAT showed significantly lower rCBF than that of aged control, but rCBF in SDAT was equal to that of lacunar stroke without dementia. Focal reduction of cerebral blood flow in bilateral fronto-parietal and left occipital regions were observed in SDAT. Verbal intelligence score (Hasegawa's score) correlated with rCBF and brain atrophy index in MID, and a tendency of correlation between rCBF and brain atrophy in MID was also observed. However, there was no correlation among those indices in SDAT. These findings suggest that the loss of brain substance dose not correspond to the reduction of rCBF in SDAT and simultaneous measurement of rCBF and brain atrophy was useful to differ SDAT from MID. (author)

Esophageal blood flow in the cat. Normal distribution and effects of acid perfusion

International Nuclear Information System (INIS)

Hollwarth, M.E.; Smith, M.; Kvietys, P.R.; Granger, D.N.

1986-01-01

The radioactive microsphere technique was used to estimate blood flow to different regions of the esophagus and to adjacent regions of the stomach before and after perfusion of the esophagus with hydrochloric acid (pH 1.5) for 5 min. Under resting conditions total blood flow, as well as blood flow to the mucosal-submucosal layer and the muscular layer, to both sphincters was significantly higher than to the esophageal body. Blood flow to the adjacent regions of the stomach was significantly higher than esophageal blood flow. Acid perfusion resulted in a large increase in total blood flow in both sphincters and the lower esophageal body. Gastric blood flow was not altered by acid perfusion. The esophageal hyperemia resulted primarily from an increase in blood flow to the muscular layer; mucosal-submucosal blood flow was increased only in the lower esophageal sphincter. The present study indicates that short periods (5 min) of gastroesophageal reflux may increase esophageal blood flow

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

Energy Technology Data Exchange (ETDEWEB)

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.

Effect of bupivacaine and adjuvant drugs for regional anesthesia on nerve tissue oximetry and nerve blood flow

Directory of Open Access Journals (Sweden)

Wiesmann T

2018-01-01

Full Text Available Thomas Wiesmann,1 Stefan Müller,1,2 Hans-Helge Müller,3 Hinnerk Wulf,1 Thorsten Steinfeldt1,4 1Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine, University Hospital Marburg, Philipps University, Marburg, 2Department of Anesthesiology and Intensive Care Medicine, University Hospital Giessen, Justus-Liebig-University, Giessen, 3Institute of Medical Biometry and Epidemiology, Philipps University, Marburg, 4Department of Anesthesiology and Intensive Care Medicine, Diakoniekrankenhaus Schwäbisch Hall, Schwäbisch Hall, Germany Background: Nerve blood flow has a critical role in acute and chronic pathologies in peripheral nerves. Influences of local anesthetics and adjuvants on tissue perfusion and oxygenation are deemed as relevant factors for nerve damage after peripheral regional anesthesia. The link between low tissue perfusion due to local anesthetics and resulting tissue oxygenation is unclear.Methods: Combined tissue spectrophotometry and laser-Doppler flowmetry were used to assess nerve blood flow in 40 surgically exposed median nerves in pigs, as well as nerve tissue oximetry for 60 min. After baseline measurements, test solutions saline (S, bupivacaine (Bupi, bupivacaine with epinephrine (BupiEpi, and bupivacaine with clonidine (BupiCloni were applied topically.Results: Bupivacaine resulted in significant decrease in nerve blood flow, as well as tissue oximetry values, compared with saline control. Addition of epinephrine resulted in a rapid, but nonsignificant, reduction of nerve blood flow and extensive lowering of tissue oximetry levels. The use of clonidine resulted in a reduction of nerve blood flow, comparable to bupivacaine alone (relative blood flow at T60 min compared with baseline, S: 0.86 (0.67–1.18, median (25th–75th percentile; Bupi: 0.33 (0.25–0.60; BupiCloni: 0.43 (0.38–0.63; and BupiEpi: 0.41(0.30–0.54. The use of adjuvants did not result in any relevant impairment of tissue oximetry

Measurement of regional cerebral blood flow with the Xenon-133 inhalation procedure in patients with cerebrovascular disease

Energy Technology Data Exchange (ETDEWEB)

Hartmann, A.

1985-10-01

Measurement of regional cerebral blood flow with inhalation of Xenon-133 and recording of regional clearance curves by stationary external detectors permits repeated estimation of bilateral cortical blood flow in resting position and after different activating procedures. Measurements can be performed on an outpatient basis, measurements in critical ill patients are possible as well. Compared to Xenon-133 single photon emission computerized tomography smaller doses can be used. Compared to Iodine-123 amphetamie SPECT actual flow calculation without arterial puncture is possible. Drawbacks of the technique are the two-dimensional imaging, unsufficient indication of the look through phenomenon and non-perfused tissue with zero-flow. However, measurement of rCBF with this technique are helpful in individual diagnosis of the following diseases: transient ischemic attacks with prolonged ischemia, communicating hydrocephalus with normal intracranial pressure, follow up studies in hemodilution, evaluation of patients with polyarterial vascular disease in respect to neurosurgical or vasculosurgical intervention, subarachnoid hemorrhage and head trauma. (orig.).

Radiotracer transit measurements as an index of regional cerebral blood flow. Pt. 1. Methodological and clinical results in chronic alcoholics cortical blood flow

International Nuclear Information System (INIS)

Dobrzanski, T.

1975-01-01

The numerical mean values of the cerebral radiorheographic index in healthy control subjects and in patients with cerebrovascular disease were not significantly different from the values of regional cerebral blood flow reported, respectively, by other authors using a modification of the Xe-133 method. In the group of chronic alcoholics there was a significant correlation between the duration of alcoholism and certain numerical values of the cerebral radiorheographic index. (author)

Regional glucose utilization and blood flow following graded forebrain ischemia in the rat: correlation with neuropathology

International Nuclear Information System (INIS)

Ginsberg, M.D.; Graham, D.I.; Busto, R.

1985-01-01

Regional patterns of cerebral glucose utilization (rCMRglc) and blood flow (rCBF) were examined in the early recovery period following transient forebrain ischemia in order to correlate early postischemic physiological events with regionally selective patterns of ischemic neuropathology. Wistar rats were subjected to 30 or 60 minutes of graded forebrain ischemia by a method combining unilateral occlusion of the common carotid artery with moderate elevation of intracranial pressure and mild hypotension; this procedure results in a high-grade ischemic deficit affecting chiefly the lateral neocortex, striatum, and hippocampus ipsilateral to the carotid occlusion. Simultaneous measurements of rCMRglc and rCBF made in regional tissue samples after 2 and 4 hours of postischemic recirculation using a double-tracer radioisotopic strategy revealed a disproportionately high level of glucose metabolism relative to blood flow in the early postischemic striatum, owing to the resumption of nearly normal rCMRglc in the face of depressed flow. In contrast, the neocortex, which had been equally ischemic, showed parallel depressions of both metabolism and blood flow during early recovery. Light microscopy at 4 and 8 hours after recovery revealed the striatum to be the predominant locus of ischemic neuronal alterations, whereas neocortical lesions were much less prominent in extent and severity at this time. The resumption of normal levels of metabolism in the setting of a disproportionate depression of rCBF in the early postischemic period may accentuate the process of neuronal injury initiated by ischemia and may contribute to the genesis of neuronal necrosis in selectively vulnerable areas of the forebrain

Focal ischaemia caused by instability of cerebrovascular tone during attacks of hemiplegic migraine. A regional cerebral blood flow study

DEFF Research Database (Denmark)

Friberg, L; Olsen, T S; Roland, P E

1987-01-01

During the course of hemiplegic migraine in 3 patients, changes in regional cerebral blood flow (rCBF) were recorded by the intracarotid 133Xe method and a 254 multidetector camera covering one hemisphere. The rCBF measurements were performed in conjunction with cerebral angiography. During...... the patients developed transient motor and/or sensory deficits and subsequently severe headache. No signs of arterial occlusion were found. In the over and underperfused regions blood flow fluctuated rapidly because of instability of cerebrovascular tone, defined as transient constriction of the smallest...

Nitric oxide and prostaglandins influence local skeletal muscle blood flow during exercise in humans: coupling between local substrate uptake and blood flow

DEFF Research Database (Denmark)

Kalliokoski, Kari K; Langberg, Henning; Ryberg, Ann Kathrine

2006-01-01

-legged dynamic knee-extension exercise. Local blockade was produced by infusing nitro-L-arginine methyl ester and indomethacin directly in the muscle via a microdialysis catheter. Blood flow and glucose uptake were measured in the region of blockade and in two additional regions of vastus lateralis muscle 1......Synergic action of nitric oxide (NO) and prostaglandins (PG) in the regulation of muscle blood flow during exercise has been demonstrated. In the present study, we investigated whether these vasodilators also regulate local blood flow, flow heterogeneity, and glucose uptake within the exercising...... skeletal muscle. Skeletal muscle blood flow was measured in seven healthy young men using near-infrared spectroscopy and indocyanine green and muscle glucose uptake using positron emission tomography and 2-fluoro-2-deoxy-D-[(18)F]glucose without and with local blockade of NO and PG at rest and during one...

Vascular structure determines pulmonary blood flow distribution

Science.gov (United States)

Hlastala, M. P.; Glenny, R. W.

1999-01-01

Scientific knowledge develops through the evolution of new concepts. This process is usually driven by new methodologies that provide observations not previously available. Understanding of pulmonary blood flow determinants advanced significantly in the 1960s and is now changing rapidly again, because of increased spatial resolution of regional pulmonary blood flow measurements.

Quantitative evaluation of regional blood flow in pulmonary sarcoidosis with Bull's eye analysis

International Nuclear Information System (INIS)

Akaki, Shiro

1991-01-01

Lung perfusion scintigraphy was performed in 23 patients with pulmonary sarcoidosis and in 11 normal volunteers. Bull's eye analysis was used to analyze regional pulmonary blood flow quantitatively. First, whole lung perfusion images were divided into three regions by three concentric circles. Then radial axes were projected from the center to define 36 x 10deg sectors. The counts for each sector were calculated and a Bull's eye image was displayed. The counts were compared with the lower limit of normal (mean -2SD), and as the indices of reduction in perfusion, extent score (ES) and severity score (SS) were calculated. ES and SS showed significant reduction in perfusion 16 patients (70%) with sarcoidosis. In stage II sarcoidosis, both ES and SS were significantly higher than in stage I sarcoidosis (p 67 Ga scintigraphy findings. In comparison with clinical data, ES had a positive correlation with serum angiotensin-converting enzyme activity (p + /CD8 + ratio (p<0.05). The Bull's eye analysis was considered useful for the quantitative evaluation of regional pulmonary blood flow in pulmonary sarcoidosis, and it was suggested that the mechanism of reduction in perfusion might result mainly in its alveolitis and angitis. Ventilation abnormality, which may happen prior to reduction in perfusion, may be an important factor of reduction in perfusion. (author)

Heterogeneity of cerebral blood flow: a fractal approach

International Nuclear Information System (INIS)

Kuikka, J.T.; Hartikainen, P.

2000-01-01

Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and single-photon emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (=coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17±0.05 (mean±SD) for the left hemisphere and 1.15±0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04±0.03 than in healthy controls. (orig.) [de

A quantitative index of regional blood flow in canine myocardium derived noninvasively with N-13 ammonia and dynamic positron emission tomography

Energy Technology Data Exchange (ETDEWEB)

Nienaber, C.A.; Ratib, O.; Gambhir, S.S.; Krivokapich, J.; Huang, S.C.; Phelps, M.E.; Schelbert, H.R. (Univ. of California, Los Angeles School of Medicine (USA))

1991-01-01

To derive a quantitative index of regional myocardial blood flow, the arterial input function of the flow tracer N-13 ammonia and the regional myocardial N-13 activity concentrations were noninvasively determined in 29 experiments in eight dogs. N-13 ammonia was administered intravenously and cross-sectional images were acquired dynamically using an ECAT III positron emission tomograph with an effective in-plane resolution of 13.46 mm full-width half-maximum. Time-activity curves were derived from the serial images by assigning regions of interest to the left ventricular myocardium and left ventricular blood pool. Tracer net extractions were estimated from the myocardial time-activity concentrations at various times after tracer injection and the integral of the arterial input function. Myocardial blood flow was altered by intravenous dipyridamole, morphine, propranolol and partial or complete occlusion of the left anterior descending coronary artery, and ranged from 9 to 860 ml/min per 100 g. Estimates of tracer net extractions were most accurate when determined from the myocardial N-13 activity concentrations at 60 s divided by the integral of the arterial input function to that time. These estimates correlated with regional myocardial blood flows determined independently by the microsphere technique by y = x (1 - 0.64(e-114/x); SEE = 22.9; r = 0.94). First pass extraction fractions of N-13 ammonia determined noninvasively with this approach declined with higher flows in a nonlinear fashion and were similar to those determined invasively by direct intracoronary N-13 ammonia injections. The findings indicate that an accurate index of regional myocardial blood flow can be obtained noninvasively by high temporal sampling of arterial and myocardial tracer activity concentrations with positron emission tomography.

An intravenous isotope method for measuring regional cerebral blood flow (rCBF) and volume (rCBV)

International Nuclear Information System (INIS)

Kuikka, J.; Ahonen, A.; Koivula, A.; Kallanranta, T.; Laitinen, J.

1977-01-01

The regional cerebal blood flow (rCBF), initial slope index (ISI), transfer time (t - sub(h)) and volume (rCBV) were measured simultaneously in 43 hospital patients using a 133 Xe intravenous injection method and quantitative dynamic 99 Tcsup(m) brain scintigraphy. The measurements were made with a gamma camera and the data processing interfaced with a small digital computer. The mean values and standard deviations were obtained from 50 control hemispheres standardized to the age of 40 years. Good agreement was found between the blood flow values determined from the intra-arterial and intravenous injection techniques. (author)

Cerebral oxygenation in the beach chair position for shoulder surgery in regional anesthesia: impact on cerebral blood flow and neurobehavioral outcome.

Science.gov (United States)

Aguirre, José A; Märzendorfer, Olivia; Brada, Muriel; Saporito, Andrea; Borgeat, Alain; Bühler, Philipp

2016-12-01

Beach chair position is considered a potential risk factor for central neurological events particularly if combined with low blood pressure. The aim of this study was to assess the impact of regional anesthesia on cerebral blood flow and neurobehavioral outcome. This is a prospective, assessor-blinded observational study evaluating patients in the beach chair position undergoing shoulder surgery under regional anesthesia. University hospital operating room. Forty patients with American Society of Anesthesiologists classes I-II physical status scheduled for elective shoulder surgery. Cerebral saturation and blood flow of the middle cerebral artery were measured prior to anesthesia and continued after beach chair positioning until discharge to the postanesthesia care unit. The anesthesiologist was blinded for these values. Controlled hypotension with systolic blood pressure≤100mm Hg was maintained during surgery. Neurobehavioral tests and values of regional cerebral saturation, bispectral index, the mean maximal blood flow of the middle cerebral artery, and invasive blood pressure were measured prior to regional anesthesia, and measurements were repeated after placement of the patient on the beach chair position and every 20 minutes thereafter until discharge to postanesthesia care unit. The neurobehavioral tests were repeated the day after surgery. The incidence of cerebral desaturation events was 5%. All patients had a significant blood pressure drop 5 minutes after beach chair positioning, measured at the heart as well as the acoustic meatus levels, when compared with baseline values (Psurgery (Pshoulder surgery had no major impact on cerebral blood flow and cerebral oxygenation. However, some impact on neurobehavioral outcome 24 hours after surgery was observed. Copyright © 2016 Elsevier Inc. All rights reserved.

Regional cerebral blood flow changes and neuropsychological functioning in early and late onset alcoholism

International Nuclear Information System (INIS)

Demir, B.; Ulug, B.; Ergun, E.; Erbas, B.

2002-01-01

Aim: Chronic alcoholism is strongly associated with morphologic and functional abnormalities in the brain. The age-of-onset of alcoholism symptoms might be of discriminating value and can be used to subdivide the population into more homogeneous groups. The aim of the study was to compare late and early onset alcoholism with regard to regional cerebral blood flow (rCBF) and neuropsychological functioning. Methods: Ten late onset (Type I) and thirteen early onset (Type II) male alcoholics were included in the study, the criterion being the age of onset for alcohol abuse. Six healthy, age-matched, male volunteers were included as a control group. rCBF changes were assessed using Tc-99m-HMPAO/SPECT after a detoxification period. Transaxial slices were assessed visually and semi quantitatively. Regional mean counts were divided to the mean counts of cerebellar and occipital regions to obtain semiquantitative ratios for superior frontal, middle frontal, inferior frontal, temporal and parietal lobes for the left and right hemispheres. The neuropsychological battery consisted of the Wisconsin Card Sorting Test, the Wechsler Memory Scale and the Word Fluency Test. Results: Type I and II groups had significantly asymmetric blood flow in the frontal region compared to control group (Left frontal percentage; Type I%46.8±2, Type II=48.3±2.3, Control=50.8±3, p=0.008). The semiquantitative ratios for the frontal subregions were lower for the patients compared to those of control group, however, statistically significant difference was observed only for the ratio of superior frontal region to occipital region in type I patients, for both left and right. The difference between the two subgroups was not statistically significant. Both groups of alcoholic patients also displayed impairment in frontal lobe functions and non-verbal memory. No significant difference was detected between the alcoholic subgroups on neuropsychological measures. There was no significant correlation

Changes in the regional cerebral blood flow after drug-induced blood-pressure reduction in patients with hypertensive intracerebral hemorrhages

International Nuclear Information System (INIS)

Kuwata, Noriyuki; Kuroda, Kiyoshi; Sato, Naoya; Konno, Hiromu; Iwabuchi, Takashi; Ogawa, Akira; Kanaya, Haruyuki.

1993-01-01

In patients with hypertensive intracerebral hemorrhages, changes in the regional cerebral blood flow (rCBF) after drug-induced blood-pressure reduction were examined by means of subtraction SPECT. The subjects were 38 patients with hypertensive intracerebral hemorrhages; 22 were putaminal hemorrhages (mean age, 56.8 years; mean hematoma volume, 18.4 cc), while 16 were thalamic hemorrhages (mean age, 61.9 years; mean hematoma volume, 7.8 cc). The rCBF was measured by means of SPECT (Tomomatic 64) with 133 Xe inhalation. Trimethaphan (an autonomic ganglion blocker) and diltiazem hydrochloride (a calcium antagonist) were used for the reduction of the blood pressure. The results were as follows: In the acute stage, the mean CBF was reduced when the blood pressure fell by more than 20% in both the putaminal hemorrhages and the thalamic hemorrhages. A similar tendency was observed in the subacute stage, except that a greater reduction in the blood pressure was needed to induce mean CBF reduction. The subtraction of rCBF maps before and after hypotension treatment shows a reduction of the rCBF in the lateral region of hematoma and the contralateral hemisphere. (author)

Regional cerebral blood flow (rCBF) changes in major depression

International Nuclear Information System (INIS)

Ohtaki, Junichi

1992-01-01

Regional cerebral blood flow (rCBF) in patients with major depression and in normal controls was measured by single photon emission computed tomography (SPECT) using N-isopropyl-p [ 123 I]-iodoamphetamine (IMP). The subjects were 22 patients with major depression and 14 normal controls. The rCBF was calculated by the ratio of activity per pixel in the cortical regions to activity per pixel in the cerebellum. IMP-SPECT was conducted in patients with major depression under the depressive and remitted states. rCBF values in the frontal, parietal, temporal, basal ganglia and the occipital regions, and the mean rCBF values were significantly lower in depressive patients than in the controls. Increased rCBF values were observed, and the mean rCBF became normal in the state of remittence. There was no significant difference in mean rCBF between depressive patients and the controls. Therefore, because the lower rCBF was normalized following improvement in expressive symptoms, the rCBF values could be useful as 'state dependent markers' in patients with major depression. (author)

Relationship between white matter lesions and regional cerebral blood flow changes during longitudinal follow up in Alzheimer's disease.

Science.gov (United States)

Hanaoka, Takuya; Kimura, Noriyuki; Aso, Yasuhiro; Takemaru, Makoto; Kimura, Yuki; Ishibashi, Masato; Matsubara, Etsuro

2016-07-01

The aim of the present study was to evaluate the relationship between baseline white matter lesions (WML) and changes in regional cerebral blood flow during longitudinal follow up of patients with Alzheimer's disease (AD). A total of 38 patients with AD were included in the study (16 men, 22 women; mean age 77.8 years). All patients were evaluated using the Mini-Mental State Examination and brain perfusion single-photon emission computed tomography at baseline with an approximately 2-year follow up. The patients were divided into two subgroups according to the presence of WML on magnetic resonance imaging. Single-photon emission computed tomography data were analyzed using a voxel-by-voxel group analysis with Statistical Parametric Mapping 8 and region of interest analysis using FineSRT. Changes in Mini-Mental State Examination scores and regional cerebral blood flow were analyzed using the Wilcoxon signed-rank test. Mean Mini-Mental State Examination scores in AD patients with WML significantly decreased from 19.4 ± 4.8 to 15.5 ± 6.5 (P = 0.003). Statistical Parametric Mapping 8 and FineSRT analysis showed more severe and widespread regional cerebral blood flow reduction, mainly in the frontal and mesial temporal regions in AD patients with WML compared with those without WML. Baseline WML could predict a rapid progression of cognitive and brain functional impairment during longitudinal follow up in AD. Geriatr Gerontol Int 2016; 16: 836-842. © 2015 Japan Geriatrics Society.

Prolonged disturbances of regional cerebral blood flow in transient ischemic attacks

International Nuclear Information System (INIS)

Hartmann, A.

1985-01-01

Regional cerebral blood flow (rCBF) was measured over both hemispheres in 20 patients with unilateral transient ischemic attacks (TIA) of the territory of the internal carotid artery on the day of the TIA. rCBF was estimated with the nontraumatic Xenon 133-inhalation technique using the initial slope index. 13 patients experienced their first TIA, 7 had several attacks. In 14 patients the first rCBF-measurement was performed during the presentation of clinical symptoms. The 2nd rCBF-measurement was done on day 2, the last one on day 7. Scans of the 15 patients studied with CT were normal. On day 1 mean rCBF of the TIA-side was significantly lower than that of the contralateral hemispheres. 22% of all areas showed a significant reduction of flow compared to mean rCBF. Mean rCBF of both the TIA- and the contralateral side was significantly reduced compared to the bi-hemispheric mean rCBF of a control group with no history of TIA or completed strokes but at least 2 risk factors for cerebrovascular disease. Whereas mean rCBF did not change in the contralateral side it increased significantly (+6.9%) in the TIA-side from day 1 to day 2 but not from there to day 7. This is reflected by the increase of the total number of ROI with normal flow from day 1 to day 2. Considering the actual flow and the flow course of that tissue which was believed to be responsible for the clinical symptoms the following regional patterns were observed: normal rCBF in 6 patients; early return to normal concomitant to the clinical course (n = 4)

Determination of myocardial blood flow by videodensitometry

International Nuclear Information System (INIS)

Erikson, U.; Helmius, G.; Hennig, K.; Johansson, L.; Enghoff, E.; Ruhn, G.

1981-01-01

Videodensitometry has hitherto been used as a tool for measuring regional blood flow in the kidneys and lungs by means of the well known Stewart Hamilton curve (wash-out) technique. This preliminary report suggests the possibility of using this method to measure coronary blood flow. Thirty-six patients, 29 of whom had angina pectoris, underwent videodensitometry in connection with coronary angiography. (orig.) [de

Subcutaneous blood flow in the temporal region of migraine patients

International Nuclear Information System (INIS)

Jensen, K.

1987-01-01

Subcutaneous blood flow in the temporal region (TSBF) was measured by the local 133 Xenon washout technique in 43 migraine patients; 19 were reexamined in the course of spontaneous attacks. During attacks, TSBF was normal compared to headache-free state. In 13 unilateral attacks, the median ipsilateral to contralateral ratio TSBF was 1: 1.276, (NS). During 30 deg C passive head-up tilt, TSBF descreased by a median of 27% during headache-free intervals and by a median, 21% during migraine attacks. The difference between the 2 occasions was not significant. Head-up tilt resulted in a median 4.5% increase in mean arterial blood pressure (MAP) and a median 5.3% increase in heart rate (HR) during headache-free intervals and 3.4% and 3.2% respectively during migraine attacks. These results are evidence against a vasomotor disturbance of the extracranial tissues during attacks of migraine. The cardio-vascular response to the orthostatic stimulus indicates a normal function of this part of the autonomic nervous system during migraine attacks. (author)

Subcutaneous blood flow in the temporal region of migraine patients

Energy Technology Data Exchange (ETDEWEB)

Jensen, K.

1987-01-01

Subcutaneous blood flow in the temporal region (TSBF) was measured by the local 133 Xenon washout technique in 43 migraine patients; 19 were reexamined in the course of spontaneous attacks. During attacks, TSBF was normal compared to headache-free state. In 13 unilateral attacks, the median ipsilateral to contralateral ratio TSBF was 1: 1.276, (NS). During 30 deg C passive head-up tilt, TSBF descreased by a median of 27% during headache-free intervals and by a median, 21% during migraine attacks. The difference between the 2 occasions was not significant. Head-up tilt resulted in a median 4.5% increase in mean arterial blood pressure (MAP) and a median 5.3% increase in heart rate (HR) during headache-free intervals and 3.4% and 3.2% respectively during migraine attacks. These results are evidence against a vasomotor disturbance of the extracranial tissues during attacks of migraine. The cardio-vascular response to the orthostatic stimulus indicates a normal function of this part of the autonomic nervous system during migraine attacks.

Regional cerebral blood flow and oxygen consumption during normal human sleep

International Nuclear Information System (INIS)

Takahashi, Ken

1989-01-01

Regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rCEF) and regional cerebral metabolic rate for oxygen (rCMRO 2 ) were measured using the continuous inhalation technique for 15 O with positron emission tomography (PET) during both wakefulness and sleep. Ten paid volunteers, with a mean age of 21.6 yrs., were deprived of sleep for a period of approximately 20 hours, and the experiments were performed mostly in the morning. 15 O activity of both whole blood and the plasma, pixel count of PET, total arterial blood oxygen content were used for analysis of rCBF, rOEF and rCMRO 2 . PET scannings were carried out mostly during the very light non-rapid eye movement (NREM) sleep, i.e. stage 1 and/or 2, and wakefulness. About 10 minutes after the start of continuous inhalation of 15 O gas, the 15 O activity of the brain was found to be in a steady-state condition. During this steady-state condition, PET scannings were performed for about 10 minutes. Regions of interest, square in shape and having an area of 2.8 cm 3 , were set in each cortex on PET images of a horizontal cross-section of the brain, set at 45 mm above the orbitomeatal line. The rCBF and rCMRO 2 were analysed in 5 of 10 male subjects during both wakefulness and NREM sleep, and only 3 were done during three sleep stages, including REM sleep. Levels of rCBF and rCMRO 2 were found to be decreased in NREM sleep, and the decreasing rates were calculated at 10.2% and 7.6% from the level of wakefulness, respectively. There was no significant difference in the mean value of rOEF between wakefulness and NREM sleep. There were no significant regional differences found in the rate of decrease among the frontal, temporal and occipital cortices. It was considered that the decrease of rCBF and rCMRO 2 during NREM sleep suggested a decrease of the activity levels in the cerebral functions. (author)

The effect of rapid decompression on femur blood flow of rabbits

International Nuclear Information System (INIS)

Yu Shaoning; Tian Wuxun; Zhu Xiangqi

1997-01-01

PURPOSE: To study the influence of regional blood flow in femur trochanter (FT) of rabbits' under rapid decompression after exposure to hyperbaric air. METHODS: Rabbits were placed in a hyperbaric chamber and exposed to the pressure of 0.5 MPa for 1.5 h, and the pressure was reduced to the atmosphere pressure at a uniform rate of 0.03 mPa/min. The regional blood flow of FT in rabbits were measured with 133 Xe washout methods. RESULTS: The normal average regional blood flow in left and right FT were 14.5 +- 1.7 and 14.1 +- 1.9 ml/(min·100g) respectively. After exposure to hyperbaric air with rapid decompression, the average regional blood flow of left and right FT were 11.1 +- 1.2 and 10.5 +- 1.6 ml/(min·100g) respectively. But the symptoms of dysbarism in these rabbits were various each other. CONCLUSIONS: After being exposed to hyperbaric air with rapid decompression, the blood flow of rabbits' femur trochanter were noticeably reduced

Supraorbital cutaneous blood flow rate during carotid endarterectomy

DEFF Research Database (Denmark)

Hove, Jens D; Rosenberg, Iben; Sejrsen, Per

2006-01-01

: The supraorbital cutaneous blood flow rate was measured by the application of heat to the skin and following the subsequent dissipation of the heat in seven patients undergoing carotid endarterectomy. At the same time, the oxygenation in the right and left frontal region was monitored by near-infrared spectroscopy......BACKGROUND: The supraorbital skin region is supplied by the supraorbital artery, which is a branch of the internal carotid artery. The supraorbital cutaneous blood flow rate may therefore be influenced by changes in the internal carotid artery flow during carotid endarterectomy. METHODS...... (NIRS). RESULTS: During cross-clamping of the carotid artery, the ipsilateral NIRS-determined frontal oxygenation tended to decrease [67 +/- 13% to 61 +/- 11% (P = 0.06); contralateral 68 +/- 11% to 66 +/- 8%] as did the supraorbital cutaneous blood flow rate from 56 +/- 23 to 44 +/- 7 ml 100 g(-1) min...

Abnormality in cerebellar blood flow in solo vertigo patients

Energy Technology Data Exchange (ETDEWEB)

Nagahori, Takeshi [Shakaihoken Takaoka Hospital, Toyama (Japan); Nishijima, Michiharu; Endo, Shunro; Takaku, Akira

1997-03-01

Little is known about the blood flow of the vertebrobasilar system as a cause of vertigo and dizziness. We used Xe-CT to study cerebellar blood flow in 53 patients who ranged in age from 35 to 85 years. The patients were divided into two groups. One of them was the vertigo group that comprised 28 patients with rotatory sensation, and the other, the non-vertigo group of 25 patients with a sensation other than rotation. At the stage of severe symptoms, there was decreased cerebellar blood flow in all patients of both, the vertigo and the non-vertigo groups, and a decrease in the bilateral cerebellar hemisphere was observed in five patients and in a unilateral hemisphere in three patients of the vertigo group. By comparison, in the non-vertigo group, unilateral decrease of cerebellar blood flow was observed in only one patient, and a bilateral decrease in five. At the stage of severe symptoms, the mean regional cerebellar blood flow was 40.5{+-}8.0 ml/100 g/min (n=16 sides) in the vertigo group and 45.3{+-}9.5 ml/100 g/min (n=12 sides) in the non-vertigo group. At the stage of moderate symptoms, blood flow image was normal in four of 14 vertigo patients and in seven of 12 non-vertigo patients. The mean regional blood flow was 47.8{+-}8.6 ml/100 g/min (n=28 sides) in the vertigo group and 47.1{+-}5.1 ml/100 g/min (n=24 sides) in the non-vertigo group. At the asymptomatic stage, a high proportion of normal blood flow images (nine of 16 vertigo patients and 10 of 10 non-vertigo patients) was observed. The mean regional cerebellar blood flow was 51.6{+-}10.7 ml/100 g/min (n=32 sides) in the vertigo group and 52.8{+-}8.5 ml/100 g/min (n=20 sides) in the non-vertigo group. This study demonstrates that a unilateral or bilateral decrease in blood flow of the vertebrobasilar system may cause vertigo and dizziness. It also shows that Xe-CT of the cerebellum may be a valuable examination modality for the diagnosis and treatment of vertigo and dizziness. (author)

Abnormality in cerebellar blood flow in solo vertigo patients

International Nuclear Information System (INIS)

Nagahori, Takeshi; Nishijima, Michiharu; Endo, Shunro; Takaku, Akira

1997-01-01

Little is known about the blood flow of the vertebrobasilar system as a cause of vertigo and dizziness. We used Xe-CT to study cerebellar blood flow in 53 patients who ranged in age from 35 to 85 years. The patients were divided into two groups. One of them was the vertigo group that comprised 28 patients with rotatory sensation, and the other, the non-vertigo group of 25 patients with a sensation other than rotation. At the stage of severe symptoms, there was decreased cerebellar blood flow in all patients of both, the vertigo and the non-vertigo groups, and a decrease in the bilateral cerebellar hemisphere was observed in five patients and in a unilateral hemisphere in three patients of the vertigo group. By comparison, in the non-vertigo group, unilateral decrease of cerebellar blood flow was observed in only one patient, and a bilateral decrease in five. At the stage of severe symptoms, the mean regional cerebellar blood flow was 40.5±8.0 ml/100 g/min (n=16 sides) in the vertigo group and 45.3±9.5 ml/100 g/min (n=12 sides) in the non-vertigo group. At the stage of moderate symptoms, blood flow image was normal in four of 14 vertigo patients and in seven of 12 non-vertigo patients. The mean regional blood flow was 47.8±8.6 ml/100 g/min (n=28 sides) in the vertigo group and 47.1±5.1 ml/100 g/min (n=24 sides) in the non-vertigo group. At the asymptomatic stage, a high proportion of normal blood flow images (nine of 16 vertigo patients and 10 of 10 non-vertigo patients) was observed. The mean regional cerebellar blood flow was 51.6±10.7 ml/100 g/min (n=32 sides) in the vertigo group and 52.8±8.5 ml/100 g/min (n=20 sides) in the non-vertigo group. This study demonstrates that a unilateral or bilateral decrease in blood flow of the vertebrobasilar system may cause vertigo and dizziness. It also shows that Xe-CT of the cerebellum may be a valuable examination modality for the diagnosis and treatment of vertigo and dizziness. (author)

Blood flow rate measurements with indicator techniques revisited

DEFF Research Database (Denmark)

Sejrsen, Per; Bülow, Jens

2009-01-01

In view of the emerging role, disturbances in regional blood flow rate seem to play in the pathogenesis of the metabolic syndrome; we review the concepts of the classical indicator dilution and washout techniques used for determinations of regional blood flow rate. Prerequisites, assumptions......, necessary precautions for the application of these experimental techniques are emphasized. Special attention has been carried out to elucidate the consequence of a choice of indicators having a large distribution volume in the tissues....

Blood flow in healed and inflamed periodontal tissues of dogs

International Nuclear Information System (INIS)

Hock, J.M.; Kim, S.

1987-01-01

The objectives of this study were to determine if increased blood flow associated with gingivitis would decrease following resolution of gingival inflammation in dogs with periodontitis; if increased blood flow in inflamed gingiva was associated with changes in the blood flow of alveolar bone, and if blood flow in gingiva and alveolar bone increased if periodontitis was reactivated by ligating teeth. Regional blood flow was measured in dogs with pre-existing periodontitis, using radioisotope-labelled, plastic microspheres. In the first experiment on 4 adult Beagle dogs, teeth in the left jaws were treated to resolve the periodontitis, while teeth in the right jaws were not treated. Gingival and bone blood flow were measured after 12 wk. Blood flow was significantly (p 1 and gingiva with G.I.<2 was significant (p<0.04). Blood flow in bone was not altered by changes in the inflammatory status of the overlying gingiva. The findings suggest that changes in blood flow associated with inflammation are reversible and that blood flow alveolar bone is regulated independently of gingival blood flow. (author)

Portable real time analysis system for regional cerebral blood flow

International Nuclear Information System (INIS)

Tiernan, T.; Entine, G.; Stump, D.A.; Prough, D.S.

1988-01-01

A very portable, regional cerebral blood flow (rCBF) analysis instrument system suitable for use in the operating theater during surgery is under development. Cadmium telluride (CdTe) solid state radiation detectors, an 8086 based data acquisition and communications module and a DEC Microvax computer are used so that the instrument is very compact, yet has the computational power to provide real time data analysis in the clinical environment. The instrument is currently being used at Bowman Gray School of Medicine to study rCBF during cardiopulmonary bypass surgery (CPB). Preliminary studies indicate that monitoring rCBF during this surgical procedure may provide insights into the mechanism that causes a significant fraction of these patients to suffer post operative neuropsychological deficit

Analysis of Regional Cerebral Blood Flow Using 99mTc-HMPAO Brain SPECT in Senile Dementia of Alzheimer Type

International Nuclear Information System (INIS)

Lee, Myung Hae; Lee, Myung Chul; Koh, Chang Soon; Roh, Jae Kyu; Woo, Chong In

1988-01-01

99m Tc-HMPAO brain SPECT studies were performed in 11 patients with Alzheimer's disease, 7 patients with psychological depression and 12 normal controls. Changes of regional cerebral blood flow was semiquantitatively analyzed and the results were as follows. 1) In 11 patients with Alzheimer's disease, significant reduction of regional cerebral blood flow was found In both temporoparietal areas. 2) Relative perfusion between cerebral hemispheres was rather symmetrical in patient with Alzheimer's disease. 3) All patients with depression showed normal SPECT findings. As for conclusion, 99m Tc-HMPAO brain SPECT seemed to be a valuable method for clinical assessment and management of patients with Alzheimer's disease.

Investigation of regional cerebral blood flow in alcoholic Korsakoff's syndrome with 123I-IMP SPECT

International Nuclear Information System (INIS)

Nakamura, Makoto; Nomura, Soichiro; Kato, Motoichiro; Nakazawa, Tsuneyuki.

1995-01-01

Regional cerebral blood flow (rCBF) was determined quantitatively by single photon emission computed tomography (SPECT) using N-isopropyl-p-[ 123 I]iodoamphetamine ( 123 I-IMP) in 6 patients with alcoholic Korsakoff's syndrome (A group). The findings were compared with concurrently available findings from 6 alcoholic patients with no evidence of cerebral disordres such as Korsakoff's syndrome and dementia (B group) and 4 healthy persons (C group). In both A and B groups, diffuse decrease in blood flow was significantly observed in the entire brain, as compared with the C group; no significant difference in the decreased blood flow existed between the A and B groups. According to the WAIS results, the patients in the A group were classified as 'typical Korsakoff's syndrome' (full IQ of 90 or more) and as 'serious Korsakoff's syndrome' (full IQ of 89 or less). rCBF in the thalamus was significantly lower in the A group of patients with typical Korsakoff's syndrome than the B group. These findings may reflect the variety of alcoholic Korsakoff's syndrome. This may also have an implication for the possible classification of several types in this syndrome. (N.K.)

Regional blood flows by the microsphere method: reproducibility in portal hypertensive rats and influence of a portal vein catheter

International Nuclear Information System (INIS)

Hadengue, A.; Lee, S.S.; Koshy, A.; Girod, C.; Lebrec, D.

1988-01-01

To determine the reproducibility of splanchnic blood flow measurements by the microsphere method in rats with portal hypertension and the effects of laparotomy with portal vein cannulation, eight groups of 10 rats were studied. Microspheres were labelled with 113 Sn or 141 Ce. Laparotomy with portal cannulation had no significant effect in sham-operated rats. In awake portal hypertensive rats, cardiac output and splanchnic blood flow were lower in portal vein cannulated rats compared with those of non-cannulated animals. In anesthetized portal hypertensive rats blood flows were unaffected by portal cannulation, but arterial pressure and heart rate were elevated. Anesthesia also decreased portal pressure in portal hypertensive rats. We conclude that the microsphere method remains reproducible in portal hypertensive rat models. Laparotomy with portal cannulation can alter systemic and splanchnic hemodynamics in portal hypertensive rats; these effects can also be changed during pentobarbital anesthesia. Regional blood flow measurements in portal hypertensive rats should be performed in animals without portal cannulation and preferably in the awake state

Interictal "patchy" regional cerebral blood flow patterns in migraine patients. A single photon emission computerized tomographic study

DEFF Research Database (Denmark)

Friberg, L; Olesen, J; Iversen, Helle Klingenberg

1994-01-01

In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right-left asymme......In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right...... rCBF images is insufficient to pick up abnormalities; (2) almost 50% of the migraine sufferers had abnormal rCBF/asymmetries. However, these are discrete compared with those typically seen during the aura phase of a migraine attack. One explanation to the patchy rCBF patterns might...

Investigation of intrarenal blood flow and urine flow aspects by scintillation camera

International Nuclear Information System (INIS)

Kawamura, J.; Hosokawa, S.; Yoshida, O.; Ishii, Y.; Torizuka, K.

1977-01-01

In order to clarify intrarenal dynamic processes related to regional distribution in patients with unilateral renal disease, two radioactive tracers, 133 Xe and /sup 99m/Tc-diethylenetriaminepentaacetic acid (/sup 99m/Tc-DTPA) were introduced into a renal artery and intrarenal blood flow and urine flow aspects were observed by scintillation camera. Cortical blood flow decreased and medullary blood flow relatively increased with the advance of renal damage. Urine flow curve from normal cortex showed two phasic patterns. One early phase might correspond to the appearance of the tracer through the proximal tubule and a second phase might correspond to the appearance of the tracer through the loop of Henle to the distal tubule. Under mannitol diuresis, two phasic urine flow curves from the cortex became obscured and the peak time of pelvic curve shifted to the earlier period. These studies were considered to be useful in evaluating unilateral renal function and might offer a good insight for intrarenal physiology concerning blood flow as well as urine flow

Quantification of cerebral blood flow via Duplex sonography

International Nuclear Information System (INIS)

Vogl, G.; Pohl, P.; Willeit, J.; Aichner, F.

1987-01-01

An attempt was made to measure quantitatively the total cerebral blood flow by means of Duplex sonography. In a group of healthy young subjects a median value for total cerebral blood flow was obtained amounting to 469 ml/min ± 30%, repeat measurements yielded a maximum deviation of ± 11%. In three patients the values obtained after severe apoplectic insult due to occlusion of the internal carotid artery were definitely below the value of the group of healthy subjects, whereas the value for the total blood flow was in the upper range of normal values in a patient with occlusion of the a. cerebri media. Comparative measurements of the regional cerebral blood flow with xenon 13 yielded in those patients with occlusion of the internal carotid artery a markedly reduced mean flow and in the patient with occlusion of the a. cerebri media a less markedly reduced mean flow. Regionally reduced perfusion was seen in all the four patients in the range of the clinically and computer tomographically well-known ischaemia zone. Thanks to the simplicity of this sonographic examination method it could be a useful decision parameter in determining the indication for a reconstruction of the carotid artery, especially in asymptotic patients. (orig.) [de

Heterogeneity of brain blood flow and permeability during acute hypertension

International Nuclear Information System (INIS)

Baumbach, G.L.; Heistad, D.D.

1985-01-01

The purpose of this study was to examine regional autoregulation of blood flow in the brain during acute hypertension. In anesthetized cats severe hypertension increased blood flow more in cerebrum (159%) and cerebellum (106%) than brain stem (58%). In contrast to the heterogeneous autoregulatory response, hypocapnia produced uniform vasoconstriction in the brain. The authors also compared vasodilatation during severe hypertension with vasodilatation during hypercapnia. During hypercapnia, blood flow increased as much in brain stem, as in cerebrum and cerebellum. Thus, regional differences in autoregulation appear to be specific for autoregulatory stimulus and are not secondary to nonspecific differences in vasoconstrictor or vasodilator capacity. To determine whether the blood-brain barrier is more susceptible to hypertensive disruption in regions with less effective autoregulation, permeability of the barrier was quantitated with 125 I-albumin. Severe hypertension produced disruption of the barrier in cerebrum but not in brain stem. Thus, there are parallel differences in effectiveness of autoregulation and susceptibility to disruption of the blood-brain barrier in different regions of the brain

A simple technique to measure regional cerebral blood flow during intravascular ballon clamping

International Nuclear Information System (INIS)

Furuhata, Shigeru; Kubo, Atsushi; Kawase, Takeshi; Ibata, Yukio; Toya, Shigeo

1988-01-01

A case of giant internal carotid ophthalmic aneurysm was presented. In order to clarify whether the patient could tolerate carotid occlusion, a ballon clamping test was performed before surgery. The cerebral blood flow was measured using early imaging by single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine ( 123 I-IMP). When the ballon clamping test was performed the tracer was injected, and scanning was performed 35 minutes after removing the catheter. This tracer enabled a 'memory of blood flow' during temporary ischemia to determine the character of quick diffusion and slow wash out, that could not be performed by other methods of cerebral blood flow measurement. SPECT with 123 I-IMP can simplify the measurement of cerebral blood flow during the balloon clamping test. (author)

Regional cerebral blood flow and oxygen consumption during normal human sleep

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Ken [Toho Univ., Tokyo (Japan). School of Medicine

1989-09-01

Regional cerebral blood flow (rCBF), regional oxygen extraction fraction (rCEF) and regional cerebral metabolic rate for oxygen (rCMRO{sub 2}) were measured using the continuous inhalation technique for {sup 15}O with positron emission tomography (PET) during both wakefulness and sleep. Ten paid volunteers, with a mean age of 21.6 yrs., were deprived of sleep for a period of approximately 20 hours, and the experiments were performed mostly in the morning. {sup 15}O activity of both whole blood and the plasma, pixel count of PET, total arterial blood oxygen content were used for analysis of rCBF, rOEF and rCMRO{sub 2}. PET scannings were carried out mostly during the very light non-rapid eye movement (NREM) sleep, i.e. stage 1 and/or 2, and wakefulness. About 10 minutes after the start of continuous inhalation of {sup 15}O gas, the {sup 15}O activity of the brain was found to be in a steady-state condition. During this steady-state condition, PET scannings were performed for about 10 minutes. Regions of interest, square in shape and having an area of 2.8 cm{sup 3}, were set in each cortex on PET images of a horizontal cross-section of the brain, set at 45 mm above the orbitomeatal line. The rCBF and rCMRO{sub 2} were analysed in 5 of 10 male subjects during both wakefulness and NREM sleep, and only 3 were done during three sleep stages, including REM sleep. Levels of rCBF and rCMRO{sub 2} were found to be decreased in NREM sleep, and the decreasing rates were calculated at 10.2% and 7.6% from the level of wakefulness, respectively. There was no significant difference in the mean value of rOEF between wakefulness and NREM sleep. There were no significant regional differences found in the rate of decrease among the frontal, temporal and occipital cortices. It was considered that the decrease of rCBF and rCMRO{sub 2} during NREM sleep suggested a decrease of the activity levels in the cerebral functions. (author).

Analysis of Regional Cerebral Blood Flow Using {sup 99m}Tc-HMPAO Brain SPECT in Senile Dementia of Alzheimer Type

Energy Technology Data Exchange (ETDEWEB)

Lee, Myung Hae; Lee, Myung Chul; Koh, Chang Soon; Roh, Jae Kyu; Woo, Chong In [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1988-03-15

{sup 99m}Tc-HMPAO brain SPECT studies were performed in 11 patients with Alzheimer's disease, 7 patients with psychological depression and 12 normal controls. Changes of regional cerebral blood flow was semiquantitatively analyzed and the results were as follows. 1) In 11 patients with Alzheimer's disease, significant reduction of regional cerebral blood flow was found In both temporoparietal areas. 2) Relative perfusion between cerebral hemispheres was rather symmetrical in patient with Alzheimer's disease. 3) All patients with depression showed normal SPECT findings. As for conclusion, {sup 99m}Tc-HMPAO brain SPECT seemed to be a valuable method for clinical assessment and management of patients with Alzheimer's disease.

Regional cerebral blood flow in the persistent vegetative state

Energy Technology Data Exchange (ETDEWEB)

Sato, Masaharu; Kuroda, Ryotaro; Ioku, Masahiko [Kinki Univ., Osakasayama, Osaka (Japan). Faculty of Medicine; and others

1989-05-01

Regional cerebral blood flow (CBF) in eight patients in a persistent vegetative state was measured and compared with that in five healthy volunteers. The patients were classified into three groups: Group 1 (locked-in syndrome) consisted of a single patient, Group 2 (typical vegetative state) of five patients, and Group 3 (prolonged coma) of two patients. CBF was measured early after onset by single photon emission computed tomography with {sup 123}I-N-isopropyl-p-iodo-amphetamine and/or {sup 99m}Tc-hexamethyl-propyleneamine oxime. The regions of interest (ROIs) were the bilateral frontal, temporal, parietal, occipital, and cerebellar areas and basal ganglia. The values obtained in these areas were averaged, and the ratio for each ROI ((the value in the ROI/the mean value) x 100) was calculated. 'Hyper-frontal distribution' of CBF was found to be rare in both the normal condition and the vegetative state. Higher CBF values were noted in the left than in the right frontal area in four of the five volunteers but in only four of the eight patients. CBF distribution in the frontal lobe was characteristic for each group: Group 1 showed high CBF bilaterally, although the elevation was statistically significant only on the right side, and Group 3 exhibited significantly low values. In Group 2, CBF was variable but, for the most part, within normal limits. Awareness was closely correlated with frontal lobe function and alteration of CBF in the frontal region. (author).

Measurement of Flow Properties of Mammalian Blood with Different Hematocrit Values Using Falling Needle Rheometer

Directory of Open Access Journals (Sweden)

Takamasa Suzuki

2014-08-01

Full Text Available The development of viscometry with high accuracy and quick operation, as well as the establishment of a data evaluation method by pathology are largely required. Especially, the flow properties of human blood are an important factor in the evaluation of blood disease on the medicine, but the method of viscometry and the data collection are not so easy. This study has been described on the viscosity measurement and their evaluations for mammalian blood (rabbit, pig and horse including human blood. A compact-sized falling needle rheometer (FNR and a flow analysis method using this device for blood have been developed, and the relationship between the apparent viscosity and physical properties (density, hematocrit value of blood have also been evaluated. Measured flow properties of blood are evaluated as a flow curve showing the relationship between the shear stress and shear rate. Observed flow curves of mammalian bloods show three typical fluid regions, these are, the Non-newtonian fluid region for a low shear rate range, the transition region and the Newtonian fluid region for a high shear rate range. Flow properties of blood in the Casson fluid region and the apparent viscosity (μ in the Newtonian fluid region are measured, and they are compared between mammals.

Cerebral blood flow, oxygen and glucose metabolism with PET in progressive supranuclear palsy

International Nuclear Information System (INIS)

Otsuka, Makoto; Ichiya, Yuici; Kuwabara, Yasuo

1989-01-01

Cerebral blood flow, cerebral oxygen metabolic rate and cerebral glucose metabolic rate were measured with positron emission tomography (PET) in four patients with progressive supranuclear palsy (PSP). Decreased blood flow and hypometabolism of oxygen and glucose were found in both subcortical and cortical regions, particularly in the striatum including the head of the caudate nucleus and the frontal cortex. The coupling between blood flow and metabolism was preserved even in the regions which showed decreased blood flow and hypometabolism. These findings indicated the hypofunction, as revealed by decreased blood flow and hypometablolism on PET, both in the striatum and the frontal cortex, and which may underlie the pathophysiological mechanism of motor and mental disturbance in PSP. (author)

Quantitation of regional cerebral blood flow corrected for partial volume effect using O-15 water and PET

DEFF Research Database (Denmark)

IIda, H.; Law, I.; Pakkenberg, B.

2000-01-01

Limited spatial resolution of positron emission tomography (PET) can cause significant underestimation in the observed regional radioactivity concentration (so-called partial volume effect or PVE) resulting in systematic errors in estimating quantitative physiologic parameters. The authors have...... formulated four mathematical models that describe the dynamic behavior of a freely diffusible tracer (H215O) in a region of interest (ROI) incorporating estimates of regional tissue flow that are independent of PVE. The current study was intended to evaluate the feasibility of these models and to establish...... a methodology to accurately quantify regional cerebral blood flow (CBF) corrected for PVE in cortical gray matter regions. Five monkeys were studied with PET after IV H2(15)O two times (n = 3) or three times (n = 2) in a row. Two ROIs were drawn on structural magnetic resonance imaging (MRI) scans and projected...

Spiral blood flow in aorta-renal bifurcation models.

Science.gov (United States)

Javadzadegan, Ashkan; Simmons, Anne; Barber, Tracie

2016-01-01

The presence of a spiral arterial blood flow pattern in humans has been widely accepted. It is believed that this spiral component of the blood flow alters arterial haemodynamics in both positive and negative ways. The purpose of this study was to determine the effect of spiral flow on haemodynamic changes in aorta-renal bifurcations. In this regard, a computational fluid dynamics analysis of pulsatile blood flow was performed in two idealised models of aorta-renal bifurcations with and without flow diverter. The results show that the spirality effect causes a substantial variation in blood velocity distribution, while causing only slight changes in fluid shear stress patterns. The dominant observed effect of spiral flow is on turbulent kinetic energy and flow recirculation zones. As spiral flow intensity increases, the rate of turbulent kinetic energy production decreases, reducing the region of potential damage to red blood cells and endothelial cells. Furthermore, the recirculation zones which form on the cranial sides of the aorta and renal artery shrink in size in the presence of spirality effect; this may lower the rate of atherosclerosis development and progression in the aorta-renal bifurcation. These results indicate that the spiral nature of blood flow has atheroprotective effects in renal arteries and should be taken into consideration in analyses of the aorta and renal arteries.

Regional glucose utilization and blood flow in experimental brain tumors studied by double tracer autoradiography

Energy Technology Data Exchange (ETDEWEB)

Kato, A.; Sako, K.; Diksic, M.; Yamamoto, Y.L.; Feindel, W.

1985-01-01

Coupling of regional glucose utilization (GLU) and blood flow (CBF) was examined in rats with implanted brain tumors (AA ascites tumor) by quantitative double tracer autoradiography using YF-2-fluorodeoxyglucose and 14C-iodoantipyrine. Four to 13 days after implantation, the animals were injected with the two tracers to obtain autoradiograms from the same brain section before and after the decay of YF. The autoradiograms were then analyzed by an image processor to obtain a metabolic coupling index (MCI = GLU/CBF). In the tumor, high GLU and low CBF were uncoupled to give a high MCI which implied anerobic glycolysis. In large tumors, the CBF was even lower. In the peri-tumoral region, GLU was reduced and reduction was lowest around the larger tumors. CBF in the peri-tumoral region was also reduced, but this reduction became less as the distance from the tumor margin increased. The GLU and CBF of white matter was little influenced by the presence of tumors except for some reduction in these values in relation to the larger tumors. The MCI in the tumor was higher than in the cortex of the same as well as the opposite hemisphere. These findings indicate that the metabolism and blood flow of the tumor and surrounding brain are variable and directly related to tumor size.

Effectiveness of treatment with donepezil hydrochloride and changes in regional cerebral blood flow in patients with Alzheimer's disease

International Nuclear Information System (INIS)

Yoshida, Tsunetaka; Ha-Kawa, S.; Yoshimura, Masafumi; Nobuhara, Kenji; Kinoshita, Toshihiko; Sawada, Satoshi

2007-01-01

The objective of this study was to elucidate the relationship between the effects of donepezil hydrochloride (donepezil) and cerebral blood flow, and to evaluate the usefulness of cerebral blood flow imaging in assessing and predicting treatment effectiveness. The subjects were 29 outpatients (12 men and 17 women; age 50-82 years; mean age 69.2 years), who had received a diagnosis of Alzheimer's disease (AD). Efficacy was evaluated before donepezil administration; after 1 month, 3 months, and 6 months of drug administration; and at 1 year after completion of administration using the Japanese version of the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog), as a measure of cognitive function. The ADAS-cog has been frequently used to evaluate cognitive function in AD patients. Patients whose ADAS-cog scores improved by 3 or more points during the observation period were classified as responders, and those with no improvement were classified as nonresponders. 123 I-iofetamine (IMP) was used for single photon emission computed tomography cerebral blood flow scintigraphy. On the basis of ADAS-cog score improvement, 22 of the 29 patients were responders (7 men and 15 women; age 50-82 years; mean age 69.0 years) and seven were nonresponders (5 men and 2 women; age 61-80 years; mean age 70.0 years). The results indicate that a difference in cerebral blood flow responsiveness after 1 month of treatment distinguishes responders from nonresponders. After 1 month, blood flow was significantly decreased in all regions of nonresponders, whereas significant increases in blood flow were seen in the anterior frontal lobe and parietal lobe of responders. At that time point, blood flow in the basal ganglion differed significantly between the two groups, indicating that this difference in responsiveness after 1 month of treatment may distinguish responders from nonresponders. In cognitive function testing, the group that exhibited a complete response showed

Cyclotron production of krypton-77 for regional cerebral blood flow measurement

International Nuclear Information System (INIS)

Houdayer, A.J.; Meyer, E.; Yamamoto, Y.L.

1977-01-01

Krypton-77 has favourable decay characteristics for use in studies of regional cerebral blood flow, and the gas may be administered by inhalation. A description is given of the preparation and separation of radioactive sources of 77 Kr gas of strength between 1 and 5 mCi. The sources were produced via the reaction 79 Br(p,3n) 77 Kr induced by 30 MeV protons in targets of NaBr powder enriched to 99.75% 79 Br. A simple and rapid separation of the other contaminants produced in the target was achieved by means of cold traps. The fresh product showed no gamma ray spectra other than those of 77 Kr and 79 Kr, and only traces of 79 Kr were present. (U.K.)

Renal cortical and medullary blood flow responses to altered NO availability in humans

DEFF Research Database (Denmark)

Damkjær, Mads; Vafaee, Manoucher; Møller, Michael L

2010-01-01

The objective of this study was to quantify regional renal blood flow in humans. In nine young volunteers on a controlled diet, the lower abdomen was CT-scanned, and regional renal blood flow was determined by positron emission tomography (PET) scanning using H(2)(15)O as tracer. Measurements were......-NMMA injection to 1.57 ± 0.17 ml·g tissue(-1)·min(-1) (P blood flow was 4.67 ± 0.31 ml·g tissue(-1)·min(-1) during control, unchanged by glyceryl nitrate, and decreased after L-NMMA [3.48 ± 0.23 ml·(g·min)(-1), P renal medullary region in which...... the measured blood flow is 1) low, 2) independent of reduction in the VOI, and 3) reactive to changes in systemic NO supply. The technique seems to provide indices of renal medullary blood flow in humans....

Myocardial blood flow during induced aortic hypertension in dogs

International Nuclear Information System (INIS)

Thai, B.N.; Levesque, M.J.; Nerem, R.M.

1986-01-01

Myocardial blood flow was measured in anesthetized dogs during control conditions and under conditions where the aortic pressure was increased due to aortic constriction or during infusion. Blood flow was measured using the radioactive microsphere technique. Radioactive microspheres (15 m Ce-141, Sr-85, and Sc-46) were injected under control, aortic constriction and arterenol infusion in four dogs and under control conditions in two others. All microsphere injections were performed under stabilized conditions. It was found that coronary blood flow rose by 80% during aortic constriction and by 158% during arterenol infusion (P < 0.05). This increase in blood flow was not uniform throughout the heart, and higher increases were observed in the middle and apex regions of the left ventricle. Furthermore, under hypertension the increase in blood flow in LAD (left anterior descending) perfused territories was slightly higher than that in CFX (left circumflex) perfused territories

In vivo evaluation of femoral blood flow measured with magnetic resonance

DEFF Research Database (Denmark)

Henriksen, O; Ståhlberg, F; Thomsen, C

1989-01-01

, corrected for the T2 decay of non-flowing blood was used to calculate the blood flow. As a reference, the blood flow in the femoral artery was measured simultaneously with an invasive indicator dilution technique. T2 of non-flowing blood was measured in vivo in popliteal veins during regional circulatory...... arrest. The mean T2 of non-flowing blood was found to be 105 +/- 31 ms. The femoral blood flow ranged between 0 and 643 ml/min measured with MRI and between 280 and 531 ml/min measured by the indicator dilution technique. There was thus poor agreement between the two methods. The results indicate......Quantitative measurements of blood flow based on magnetic resonance imaging (MRI) using conventional multiple spin echo sequences were evaluated in vivo in healthy young volunteers. Blood flow was measured using MRI in the femoral vein. The initial slope of the multiple spin echo decay curve...

Blood flow in healed and inflamed periodontal tissues of dogs

Energy Technology Data Exchange (ETDEWEB)

Hock, J.M.; Kim, S.

1987-01-01

The objectives of this study were to determine if increased blood flow associated with gingivitis would decrease following resolution of gingival inflammation in dogs with periodontitis; if increased blood flow in inflamed gingiva was associated with changes in the blood flow of alveolar bone, and if blood flow in gingiva and alveolar bone increased if periodontitis was reactivated by ligating teeth. Regional blood flow was measured in dogs with pre-existing periodontitis, using radioisotope-labelled, plastic microspheres. In the first experiment on 4 adult Beagle dogs, teeth in the left jaws were treated to resolve the periodontitis, while teeth in the right jaws were not treated. Gingival and bone blood flow were measured after 12 wk. Blood flow was significantly (p<0.05) lower in non-inflamed healed gingiva (32.1 +- 2.7 ml/min/100 g) than in inflamed gingiva (46.1 +- 5.3 ml/min/100 g). No differences in the blood flow of the alveolar bone underlying inflamed or non-inflamed gingiva were present. In the second experiment, the right mandibular teeth of 5 dogs were treated to resolve periodontitis while teeth in the other quadrants were ligated for 4, 10 or 12 wk. The duration of ligation did not alter blood flow. Gingival blood flow around ligated maxillary and mandibular teeth was comparable and approximately 54% higher than around non-ligated teeth (p<0.03). The difference in blood flow between gingiva with G.I.>1 and gingiva with G.I.<2 was significant (p<0.04). Blood flow in bone was not altered by changes in the inflammatory status of the overlying gingiva. The findings suggest that changes in blood flow associated with inflammation are reversible and that blood flow alveolar bone is regulated independently of gingival blood flow.

In vivo evaluation of femoral blood flow measured with magnetic resonance

International Nuclear Information System (INIS)

Henriksen, O.; Staahlberg, F.; Thomsen, C.; Moegelvang, J.; Persson, B.; Lund Univ.

1989-01-01

Quantitative measurements of blood flow based on magnetic resonance imaging (MRI) using conventional multiple spin echo sequences were evaluated in vivo in healthy young volunteers. Blood flow was measured using MRI in the femoral vein. The initial slope of the multiple spin echo decay curve, corrected for the T2 decay of non-flowing blood was used to calculate the blood flow. As a reference, the blood flow in the femoral artery was measured simultaneously with an invasive indicator dilution technique. T2 of non-flowing blood was measured in vivo in popliteal veins during regional circulatory arrest. The mean T2 of non-flowing blood was found to be 105±31 ms. The femoral blood flow ranged between 0 and 643 ml/min measured with MRI and between 280 and 531 ml/min measured by the indicator dilution technique. There was thus poor agreement between the two methods. The results indicate that in vivo blood flow measurements made with MRI based on wash-out effects, commonly used in multiple spin echo imaging, do not give reliable absolute values for blood flow in the femoral artery or vein. (orig.)

Regional cerebral blood flow changes associated with clitorally induced orgasm in healthy women.

Science.gov (United States)

Georgiadis, Janniko R; Kortekaas, Rudie; Kuipers, Rutger; Nieuwenburg, Arie; Pruim, Jan; Reinders, A A T Simone; Holstege, Gert

2006-12-01

There is a severe lack of knowledge regarding the brain regions involved in human sexual performance in general, and female orgasm in particular. We used [15O]-H2O positron emission tomography to measure regional cerebral blood flow (rCBF) in 12 healthy women during a nonsexual resting state, clitorally induced orgasm, sexual clitoral stimulation (sexual arousal control) and imitation of orgasm (motor output control). Extracerebral markers of sexual performance and orgasm were rectal pressure variability (RPstd) and perceived level of sexual arousal (PSA). Sexual stimulation of the clitoris (compared to rest) significantly increased rCBF in the left secondary and right dorsal primary somatosensory cortex, providing the first account of neocortical processing of sexual clitoral information. In contrast, orgasm was mainly associated with profound rCBF decreases in the neocortex when compared with the control conditions (clitoral stimulation and imitation of orgasm), particularly in the left lateral orbitofrontal cortex, inferior temporal gyrus and anterior temporal pole. Significant positive correlations were found between RPstd and rCBF in the left deep cerebellar nuclei, and between PSA and rCBF in the ventral midbrain and right caudate nucleus. We propose that decreased blood flow in the left lateral orbitofrontal cortex signifies behavioural disinhibition during orgasm in women, and that deactivation of the temporal lobe is directly related to high sexual arousal. In addition, the deep cerebellar nuclei may be involved in orgasm-specific muscle contractions while the involvement of the ventral midbrain and right caudate nucleus suggests a role for dopamine in female sexual arousal and orgasm.

Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

International Nuclear Information System (INIS)

Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F.

1989-01-01

Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

Regional cerebral blood flow in schizophrenics. Tests using the xenon Xe 133 inhalation method

International Nuclear Information System (INIS)

Ariel, R.N.; Golden, C.J.; Berg, R.A.; Quaife, M.A.; Dirksen, J.W.; Forsell, T.; Wilson, J.; Graber, B.

1983-01-01

Measurements of intrahemispheric and bilateral regional cerebral blood flow (CBF) for gray and white matter were compared in 29 schizophrenic patients and 22 normal controls, using the xenon Xe 133 inhalation method. Results showed significantly lower CBF values for all brain regions in the schizophrenic group, and post hoc comparisons showed relatively greater reduced gray-matter CBF values in the anterior areas of the brain. There was also a left-hemisphere frontal loss similar to that reported previously, although it was in the context of a generalized loss in anterior functioning. Interhemispheric comparison within both groups showed no differences between homologous regions for gray matter, and greater white-matter CBF values in the right hemisphere than in the left hemisphere. The findings support a hypothesis of a bilateral anterior deficit in schizophrenia

Regional cerebral blood flow changes in patients with internet addiction: Authors' reply.

Science.gov (United States)

Liu, Guobing; Shi, Hongcheng

2016-01-01

To the comments of Prof. Andreas Otte to our work we reply as follows: As was mentioned by Prof. Andreas Otte, our study was the first study of regional cerebral blood flow changes in patients with internet addiction. Therefore, there was not much previous, established experience to refer to. As an exploration study, it was inevitable that there were some insufficiencies. We feel great appreciation to Prof. Andreas Otte for his comments on our work, which will improve our studying quality in this field in the future. Prof. Andreas Otte inquired in his letter how the regional cerebral blood flow (rCBF) was calculated, and was scaled, relatively to the whole brain mean value or to the cerebellar mean value. All rCBF data were scaled relatively to the whole brain, in our study. As for the question in relation to the test level, the P-value of 0.05 was only used when comparing intergroup differences of baseline or clinical information of patients using SPSS, while the P-value of 0.01 was used for the statistical parametric mapping (SPM) t-test. We had tried using the test level of Pfalse-positive results. However, in order to control false-positive errors, we performed intragroup comparisons from rest to adenosine-stressed status firstly by paired t test to identify cerebral regions with obvious rCBF changes because of administration of adenosine. On the basis of these cerebral regions, we subsequently performed a two-sample t test to compare intergroup differences to identify cerebral regions with rCBF that could have attributed to internet addiction. We believed that this "twostep" statistical mode might reduce the probability of falsepositive results to some extent. As for the cluster question in relation to SPM analysis, it seems more problematic and more prone for clusterwise inference to produce false-positive results than voxelwise inference, as mentioned in the paper by Eklund et al (2016). We did not take the two-way ANOVA analysis, instead, we performed the

Regional cerebral blood flow in diagnosis of childhood onset partial epilepsy

International Nuclear Information System (INIS)

Mitsuyoshi, Izuru; Tamaki, Kyoko; Mutoh, Kozo; Iwasaki, Yasushi; Konishi, Junji; Mikawa, Haruki; Okuno, Takehiko.

1993-01-01

We compared regional cerebral blood flow assessed by [ 123 I]N-isopropyl-p-iodoamphetamine (IMP) single-photon emission tomography (SPECT) with magnetic resonance imaging (MRI), computed tomography (CT) and interictal surface electroencephalography (EEG) to evaluate its diagnostic potential in 24 patients with partial seizures with onset in childhood. Focal low uptake areas were observed in SPECT scans of 18 patients and were presumed to represent epileptogenic areas in 17. MRI revealed an abnormality in 12 and CT in 6 patients, and all organic lesions showed SPECT abnormalities, too. Six patients without focal structural abnormalities showed regional perfusion deficit on SPECT. Routine scalp EEG revealed an epileptic focus in 17 patients and three of them showed discordant results between SPECT and EEG, which suggested more serious brain disorders. In two patients without EEG localization only SPECT showed focal abnormalities in the probable epileptic area. [ 123 I]IMP-SPECT was useful in locating the epileptic focus, particularly during the early period after the onset of partial seizures when the EEG gave inconclusive results. (author)

Investigation of regional cerebral blood flow in alcoholic Korsakoff`s syndrome with {sup 123}I-IMP SPECT

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Makoto; Nomura, Soichiro [Tachikawa Hospital, Tokyo (Japan); Kato, Motoichiro; Nakazawa, Tsuneyuki

1995-05-01

Regional cerebral blood flow (rCBF) was determined quantitatively by single photon emission computed tomography (SPECT) using N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) in 6 patients with alcoholic Korsakoff`s syndrome (A group). The findings were compared with concurrently available findings from 6 alcoholic patients with no evidence of cerebral disordres such as Korsakoff`s syndrome and dementia (B group) and 4 healthy persons (C group). In both A and B groups, diffuse decrease in blood flow was significantly observed in the entire brain, as compared with the C group; no significant difference in the decreased blood flow existed between the A and B groups. According to the WAIS results, the patients in the A group were classified as `typical Korsakoff`s syndrome` (full IQ of 90 or more) and as `serious Korsakoff`s syndrome` (full IQ of 89 or less). rCBF in the thalamus was significantly lower in the A group of patients with typical Korsakoff`s syndrome than the B group. These findings may reflect the variety of alcoholic Korsakoff`s syndrome. This may also have an implication for the possible classification of several types in this syndrome. (N.K.).

Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

International Nuclear Information System (INIS)

Knopman, D.S.; Rubens, A.B.; Selnes, O.A.; Klassen, A.C.; Meyer, M.W.

1984-01-01

In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery

Findings of 99mTc-HMPAO Regional Cerebral Blood Flow SPECT in a Case of Herpes Simplex Encephalitis

International Nuclear Information System (INIS)

Ahn, Myeong Im; Lee, Sung Yong; Kim, Jong Woo; Bahk, Yong Whee

1989-01-01

Herpes simplex encephalitis (HSE) is one of the fulminant necrotizing, often fatal sporadic form of the encephalitis caused by herpes simplex type I virus. Characteristically, there is early and almost constant involvement of one or both temporal lobes, although there are common additional areas of involvement. Appropriate early treatment following correct diagnosis by clinical findings, CSF study, EEG and several radiological studies including angiography, radionuclide studies, CT or MRI can reduce its mortality and severity of the sequelae. We report a case of HSE diagnosed by adjuvant study of 99m Tc-HMPAO regional cerebral blood flow SPECT, which showed a marked increase in bitemporal cerebral blood flow in a 24-year-old man.

Trial on MR portal blood flow measurement with phase contrast technique

International Nuclear Information System (INIS)

Tsunoda, Masatoshi; Kimoto, Shin; Togami, Izumi

1991-01-01

Portal blood flow measurement is considered to be important for the analysis of hemodynamics in various liver diseases. The Doppler ultrasound method has been used extensively during the past several years for measuring portal blood flow, as a non-invasive method. However, the Doppler ultrasound technique do not allow the portal blood flow to be measured in cases of obesity, with much intestinal gas, and so on. In this study, we attempted to measure the blood flow in the main trunk of portal vein as an application of MR phase contrast technique to the abdominal region. In the flow phantom study, the flow volumes and the velocities measured by phase contrast technique showed a close correlation with those measured by electromagnetic flowmeter. In the clinical study with 10 healthy volunteers, various values of portal blood flow were obtained. Mean portal blood flow could be measured within the measuring time (about 8 minutes) under natural breathing conditions. Phase contrast technique is considered to be useful for the non-invasive measurement of portal blood flow. (author)

Renal cortical and medullary blood flow responses to altered NO-availability in humans

DEFF Research Database (Denmark)

Damkjaer, Mads; Vafaee, Manoucher; Møller, Michael Lehd

2010-01-01

The objective was to quantify regional renal blood flow in humans. In nine young volunteers on a controlled diet, the lower abdomen was CT-scanned and regional renal blood flow determined by positron emission tomography (PET) scanning using H(2)(15)O as tracer. Measurements were performed...... of one voxel were eliminated stepwise from the external surface of the VOI ('voxel peeling'), and the blood flow subsequently determined in each new, reduced VOI. Blood flow in the shrinking volumes of interest (VOIs) decreased as the number of cycles of voxel peeling increased. After 4-5 cycles, blood...... flow was not reduced further by additional voxel peeling. This volume-insensitive flow was measured to be 2.30 ±0.17 ml·(g·min)(-1) during the control period; it increased during infusion of glyceryl nitrate to 2.97 ±0.18 ml·(g·min)(-1) (p...

Assessment of regional myocardial blood flow with N-13 ammonia PET

International Nuclear Information System (INIS)

Himi, Toshiharu

1992-01-01

Regional myocardial blood flow (RMBF) has been assessed with O-15 water, O-15 CO 2 and N-13 ammonia in Japan, and O-15 water has been used most commonly for quantitative measurement of RMBF with Iida's method. Though myocardial image quality with N-13 ammonia is superior to that with O-15 water or that with O-15 CO 2 , RMBF was not assessed quantitatively with N-13 ammonia. We have attempted to assess RMBF non-invasively with N-13 ammonia and dynamic PET. Yoshida et. al applied the first-pass flow model to N-13 ammonia dynamic PET for measurement of RMBF. We could measure RMBF of the patients with hypertrophic cardiomyopathy (HCM) and could assess effects of vaso-dilating agents on RMBF non-invasively with this method. But this method dose not take account of cross-contamination of recorded counts between myocardium and surrounding tissues, and hence we have applied factor analysis to dynamic PET for correction of that. It was suggested that cross-contamination in normal cases could be corrected by the factor analysis and there were few cross-contamination in the patients with HCM. (author)

Regional cerebral blood flow abnormalities in patients with primary hyperparathyroidism

International Nuclear Information System (INIS)

Cermik, Tevfik F.; Kaya, Meryem; Bedel, Deniz; Berkarda, Sakir; Yigitbasi, Oemer N.; Ugur-Altun, Betuel

2007-01-01

We assessed the alterations in regional cerebral blood flow (rCBF) in patients with primary hyperparathyroidism (PHP) before parathyroidectomy by semiquantitative analysis of brain single photon emission computed tomography (SPECT) images. Included in this prospective study were 14 patients (mean age 47.6 ± 10.4 years; 3 male, 11 female) and 10 control subjects (mean age 36.0 ± 8.5 years, 6 male, 4 female) were SPECT imaging was performed using a dual-headed gamma camera 60-90 min after intravenous administration of 925 MBq Tc-99m HMPAO. The corticocerebellar rCBF ratios were calculated from 52 brain areas and reference lower values (RLVs) were calculated from the rCBF ratios of control subjects. The regional ratios that were below the corresponding RLV were considered abnormal (hypoperfused). Hypoperfusion was shown in 171 out of 728 regions (23%) and there was a significant correlation between serum calcium, PTH levels and the sum of hypoperfused regions in the patient group (R = 0.75 and P = 0.001, and R = 0.75, P = 0.001, respectively). Significantly reduced rCBF were found in the following cortical regions: bilateral cingulate cortex, superior and inferior frontal cortex, anterior temporal cortex, precentral gyrus, postcentral gyrus and parietal cortex, and right posterior temporal cortex. Our results indicate that alterations in rCBF in patients with PHP can be demonstrated with brain SPECT. The correlation between serum calcium, PTH levels and the sum of hypoperfused regions indicates that there may be a strong relationship between rCBF abnormalities and increased levels of serum calcium and PTH. In addition, the degree of rCBF abnormalities could be determined by brain SPECT in PHP patients with or without psychiatric symptoms. (orig.)

Regional cerebral blood flow abnormalities in patients with primary hyperparathyroidism

Energy Technology Data Exchange (ETDEWEB)

Cermik, Tevfik F. [Hospital of the University of Trakya, Department of Nuclear Medicine, Edirne (Turkey); Trakya Universitesi Hastanesi, Nukleer Tip Anabilim Dali, Gullapoglu Yerleskesi, Edirne (Turkey); Kaya, Meryem; Bedel, Deniz; Berkarda, Sakir; Yigitbasi, Oemer N. [Hospital of the University of Trakya, Department of Nuclear Medicine, Edirne (Turkey); Ugur-Altun, Betuel [Hospital of the University of Trakya, Department of Internal Medicine, Division of Endocrinology, Edirne (Turkey)

2007-04-15

We assessed the alterations in regional cerebral blood flow (rCBF) in patients with primary hyperparathyroidism (PHP) before parathyroidectomy by semiquantitative analysis of brain single photon emission computed tomography (SPECT) images. Included in this prospective study were 14 patients (mean age 47.6 {+-} 10.4 years; 3 male, 11 female) and 10 control subjects (mean age 36.0 {+-} 8.5 years, 6 male, 4 female) were SPECT imaging was performed using a dual-headed gamma camera 60-90 min after intravenous administration of 925 MBq Tc-99m HMPAO. The corticocerebellar rCBF ratios were calculated from 52 brain areas and reference lower values (RLVs) were calculated from the rCBF ratios of control subjects. The regional ratios that were below the corresponding RLV were considered abnormal (hypoperfused). Hypoperfusion was shown in 171 out of 728 regions (23%) and there was a significant correlation between serum calcium, PTH levels and the sum of hypoperfused regions in the patient group (R = 0.75 and P = 0.001, and R = 0.75, P = 0.001, respectively). Significantly reduced rCBF were found in the following cortical regions: bilateral cingulate cortex, superior and inferior frontal cortex, anterior temporal cortex, precentral gyrus, postcentral gyrus and parietal cortex, and right posterior temporal cortex. Our results indicate that alterations in rCBF in patients with PHP can be demonstrated with brain SPECT. The correlation between serum calcium, PTH levels and the sum of hypoperfused regions indicates that there may be a strong relationship between rCBF abnormalities and increased levels of serum calcium and PTH. In addition, the degree of rCBF abnormalities could be determined by brain SPECT in PHP patients with or without psychiatric symptoms. (orig.)

Corticosteroid Reduces Blood Flow to Femoral Heads in Rabbits.

Science.gov (United States)

Hou, S.M.; Liu, T.K.; Kao, M.C.

1994-12-01

Avascular necrosis of the femoral head is one of the common problems in orthopedic practice in Taiwan. The subchondral bone loses its blood supply which weakens its biomechanical support. Steroid overuse is one of many possible etiologies in reducing blood flow to the femoral head. Laser Doppler velocimeter is a precise monitor of regional blood flow of bone which is expressed in perfusion units (PU). In the control group the rabbits were injected with normal saline and there were no statistical differences between blood flow to the right hip (39.26 +/- 5.64 PU) and left hip (38.58 +/- 4.35 PU). In group B a weekly injection of methylprednisolone into rabbits for 6 weeks demonstrated the reduction of blood flow of femoral head (24.74 +/- 3.13 PU) by the laser Doppler velocimeter. The flow decreased further (15.93 +/- 2.33 PU) by 12 weeks of steroid treatment. In group C after a weekly injection of steroid for 6 weeks the flow became 31.63 +/- 4.79 PU. The steroid was then discontinued for 3 weeks and the flow was 34.6 +/- 1.34 PU. In group D the blood flow was 25.89 +/- 4.01 PU after 6 weeks of steroid treatment and we stopped the steroid for 6 weeks, the blood flow became 29.86 +/- 2.59 PU. The merit of our experiment established a model of study in avascular necrosis of the femoral head in rabbits. Copyright 1994 S. Karger AG, Basel

Regional cerebral blood flow in Parkinson's disease measured with N-isopropyl-p-[123I]iodoamphetamine (IMP) SPECT

International Nuclear Information System (INIS)

Odano, Ikuo; Nishihara, Mamiko; Hayashi, Hiroko; Higuchi, Shoichi; Sakai, Kunio; Ishikawa, Atsushi; Ibayashi, Katsuhiko.

1992-01-01

N-isopropyl-p-[ 123 I]iodoamphetamine (IMP) SPECT studies were performed on 21 patients (13 females; 45-73 yrs) with idiopathic Parkinson's disease (PD) and 10 age-matched normal controls (39-69 yrs). Regional cerebral blood flow (rCBF) was quantitatively measured by the arterial blood sampling method. When compared with normal controls, global CBF, and rCBF in the frontal cortex and in the basal ganglia were reduced 22.1% (p 123 I-IMP SPECT imaging is useful for evaluation and follow-up of patients with PD. (author)

Type of aphasia and regional cerebral blood flow. A study with /sup 133/Xe inhalation method

Energy Technology Data Exchange (ETDEWEB)

Tagawa, Koichi; Sugimoto, Keiko; Minematsu, Kazuo; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru (National Cardiovascular Center, Suita, Osaka (Japan))

1982-11-01

In 40 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured after 2 months of ictus with /sup 133/Xe inhalation method. There were 18 cases with motor aphasia and 22 with sensory aphasia. On the measurements of rCBF, 3 detectors were placed over frontal region (group F), 3 over temporal region (group T), and remaining 3 over parietal region (group P), of the dominant hemisphere. The flow values were compared with the rCBF values obtained from 21 control subjects who had no abnormality in CT scan and on neurological examinations. The control subjects revealed the hyperfrontal pattern of flow distribution; rCBF values in groups F, T and P, which were expressed as an initial slope index, were 50.0 +- 4.8, 48.0 +- 5.1 and 47.4 +- 4.5, respectively. The hyperfrontal pattern was absent in cases with motor aphasia. In this group, rCBF in groups F, T and P were 42.0 +- 8.3, 44.7 +- 8.4 and 41.0 +- 8.5, respectively, and rCBF in frontal region was significantly reduced compared with that in the control group. In sensory aphasia, rCBF values in groups F, T and P were all significantly reduced compared to the controls showing 44.0 +- 5.7, 42.8 +- 5.1 and 40.6 +- 5.4, respectively. In this group, the hyperfrontal pattern was maintained at a low flow level. When absolute rCBF values were compared between motor and sensory aphasia, there was no significant difference between these 2 groups. However, regional flow distribution in motor aphasia was significantly different from that of sensory aphasia, and the cases having the lowest value in group F were more frequently found in the former than in the latter.

Role of hypotension in decreasing cerebral blood flow in porcine endotoxemia

International Nuclear Information System (INIS)

Miller, C.F.; Breslow, M.J.; Shapiro, R.M.; Traystman, R.J.

1987-01-01

The role of reduced arterial blood pressure (MAP) in decreasing cerebral blood flow (CBF) during endotoxemia was studied in pentobarbital-anesthetized pigs. Microspheres were used to measure regional CBF changes during MAP manipulations in animals with and without endotoxin. Endotoxin decreased MAP to 50 mmHg and decreased blood flow to the cortex and cerebellum without affecting cerebral cortical oxygen consumption (CMRo 2 ). Elevating MAP from 50 to 70 mmHg during endotoxemia with norepinephrine did not change cortical blood flow or CMRo 2 but increased cerebellar blood flow. Brain stem blood flow was not affected by endotoxin or norepinephrine. When MAP was decreased to 50 mmHg by hemorrhage without endotoxin, no change in blood flow to cortex, cerebellum, or brain stem was observed from base-line levels. These results suggest that decreased MAP below a lower limit for cerebral autoregulation does not account for the decreased CBF observed after endotoxin

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

Energy Technology Data Exchange (ETDEWEB)

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).

Subcutaneous blood flow in man during sleep with continous epdural anaesthesia

DEFF Research Database (Denmark)

Sindrup, JH; Petersen, Lars Jelstrup; Kastrup, Jens

1996-01-01

BACKGROUND: Subcutaneous blood flow increases during sleep and we evaluated if this increase is affected by epidural anaesthesia. METHODS: Lower leg subcutaneous blood flow was determined by 133Xenon clearance in ten subjects during continous epidural anaesthesia at L2-L3 including eight hours...... of sleep, while the opper abdominal subcutaneous blood flow served as control. RESULTS: Epidural anaesthesia to the level of the umbilicus was followed by an increase in the lower leg subcutaneous blood flow fra 3.4 (1.8-6.3) to 7.8 (3.6-16.9) ml min-1 (median and range; P....4-7.6) ml min-1 100 g-1 after 88 (45-123) min. In contrast, until the period of sleep the upper abdominal region blood flow remained at 5.2 (3.2-6.4) ml min-1 100 g-1. During sleep, lower leg subcutaneous blood flow did not change significantly, but the upper abdominal flow increased to 6.2 (5.2-7.2) ml min...

Altered Regional Cerebral Blood Flow in Chronic Whiplash Associated Disorders.

Science.gov (United States)

Vállez García, David; Doorduin, Janine; Willemsen, Antoon T M; Dierckx, Rudi A J O; Otte, Andreas

2016-08-01

There is increasing evidence of central hyperexcitability in chronic whiplash-associated disorders (cWAD). However, little is known about how an apparently simple cervical spine injury can induce changes in cerebral processes. The present study was designed (1) to validate previous results showing alterations of regional cerebral blood flow (rCBF) in cWAD, (2) to test if central hyperexcitability reflects changes in rCBF upon non-painful stimulation of the neck, and (3) to verify our hypothesis that the missing link in understanding the underlying pathophysiology could be the close interaction between the neck and midbrain structures. For this purpose, alterations of rCBF were explored in a case-control study using H2(15)O positron emission tomography, where each group was exposed to four different conditions, including rest and different levels of non-painful electrical stimulation of the neck. rCBF was found to be elevated in patients with cWAD in the posterior cingulate and precuneus, and decreased in the superior temporal, parahippocampal, and inferior frontal gyri, the thalamus and the insular cortex when compared with rCBF in healthy controls. No differences in rCBF were observed between different levels of electrical stimulation. The alterations in regions directly involved with pain perception and interoceptive processing indicate that cWAD symptoms might be the consequence of a mismatch during the integration of information in brain regions involved in pain processing. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Altered Regional Cerebral Blood Flow in Chronic Whiplash Associated Disorders

Directory of Open Access Journals (Sweden)

David Vállez García

2016-08-01

Full Text Available There is increasing evidence of central hyperexcitability in chronic whiplash-associated disorders (cWAD. However, little is known about how an apparently simple cervical spine injury can induce changes in cerebral processes. The present study was designed (1 to validate previous results showing alterations of regional cerebral blood flow (rCBF in cWAD, (2 to test if central hyperexcitability reflects changes in rCBF upon non-painful stimulation of the neck, and (3 to verify our hypothesis that the missing link in understanding the underlying pathophysiology could be the close interaction between the neck and midbrain structures. For this purpose, alterations of rCBF were explored in a case-control study using H215O positron emission tomography, where each group was exposed to four different conditions, including rest and different levels of non-painful electrical stimulation of the neck. rCBF was found to be elevated in patients with cWAD in the posterior cingulate and precuneus, and decreased in the superior temporal, parahippocampal, and inferior frontal gyri, the thalamus and the insular cortex when compared with rCBF in healthy controls. No differences in rCBF were observed between different levels of electrical stimulation. The alterations in regions directly involved with pain perception and interoceptive processing indicate that cWAD symptoms might be the consequence of a mismatch during the integration of information in brain regions involved in pain processing.

Attacks of common migraine or hortons headache may not be accompanied by changes in regional cerebral blood flow

International Nuclear Information System (INIS)

Henriksen, L.; Aebelholt Krabbe, A.; Tfelt-Hansen, P.; Olesen, J.

1982-01-01

Vasospasm and cerebral ischemia, followed by cerebral and extracerebral vasodilation and hyperemia, are generally believed to form the common pathophysiology of the various subtypes of migraine. Mild forms of reactions are thought to result in common migraine (no neurological prodromes or accompaniments), and more severe reactions are thought to induce classical migraine. 8 induced common migraine attacks in 6 patients do not support this unitarian view, as no regional cerebral blood flow changes was found, but suggests a different pathophysiology in common migraine compaired to classical migraine. There are few features in Hortons headache to incriminate the cerebral vessels, and generally patients do not have symptoms attributable to cerebral involvement. In 6 out of 14 patients with known Hortons headache we succesfully induced an attack after alcohol alone or in combination with sublingual nitroglycerine. A slight hyperventilation occurred during the attack, correcting cerebral blood flow for these changes left mean CBF totally unchanged. No regional abnormalities occurred in any of the about 700 regions measured from during each investigation in neither the group with common migraine, nor in the patients with Hortons headache. (Author)

Critical appraisal of cerebral blood flow measured from brain stem and cerebellar regions after 133 Xe inhalation in humans

International Nuclear Information System (INIS)

Juge, O.; Meyer, J.S.; Sakai, F.; Yamaguchi, F.; Yamamoto, M.; Shaw, T.

1979-01-01

Validity of regional blood flow (rCBF) measurements recorded over the human posterior fossa after 133Xe inhalation was tested. Recording of counts from both brain stem and cerebellum (BSC) was reproducible and contamination by counts derived from surrounding anatomical structures was low and no greater than that found over hemispheres. BSC flow values showed significant correlation with the state of awareness as judged by clinical and EEG evaluation

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion

Energy Technology Data Exchange (ETDEWEB)

Caldwell, J.H.; Martin, G.V.; Link, J.M.; Krohn, K.A.; Bassingthwaighte, J.B. (Seattle VA Medical Center, WA (USA))

1990-01-01

Imaging {sup 123}I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, {sup 131}I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 {plus minus} 0.43) was similar to that for microspheres (0.94 {plus minus} 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion

International Nuclear Information System (INIS)

Caldwell, J.H.; Martin, G.V.; Link, J.M.; Krohn, K.A.; Bassingthwaighte, J.B.

1990-01-01

Imaging 123 I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131 I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 ± 0.43) was similar to that for microspheres (0.94 ± 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal

Iodophenylpentadecanoic acid-myocardial blood flow relationship during maximal exercise with coronary occlusion.

Science.gov (United States)

Caldwell, J H; Martin, G V; Link, J M; Krohn, K A; Bassingthwaighte, J B

1990-01-01

Imaging 123I-labeled iodophenylpentadecanoic acid (IPPA) uptake and clearance from the myocardium following exercise has been advocated as a means of detecting myocardial ischemia because fatty acid deposition is enhanced and clearance prolonged in regions of low flow. However, normal regional myocardial blood flows are markedly heterogeneous, and it is not known how this heterogeneity affects regional metabolism or substrate uptake and thus image interpretation. In five instrumented dogs running at near maximal workload on a treadmill, 131I-labeled IPPA and 15-micron 46Sc microspheres were injected into the left atrium after 30 sec of circumflex coronary artery occlusion. Microsphere and IPPA activity were determined in 250 mapped pieces of myocardium of approximately 400 mg. Myocardial blood flows (from microspheres) ranged from 0.05 to 7.6 ml/min/g. Deposition of IPPA was proportional to regional flows (r = 0.83) with an average retention of 25%. The mean endocardial-epicardial ratio for IPPA (0.90 +/- 0.43) was similar to that for microspheres (0.94 +/- 0.47; p = 0.08). Thus, initial IPPA deposition during treadmill exercise increases in proportion to regional myocardial blood flow over a range of flows from very low to five times normal.

Noninvasive regional cerebral blood flow measurements at pre- and post-acetazolamide test using 99mTc-ECD

International Nuclear Information System (INIS)

Matsuda, Hiroshi; Nakano, Seigo; Tanaka, Masaaki.

1996-01-01

A technique for serial noninvasive cerebral blood flow measurements at pre- and post-acetazolamide (Diamox) test was newly developed using 99m Tc-ECD without blood sampling. Baseline mean cerebral blood flow (mCBF) was measured from graphical analysis of time activity curves for brain and aortic arch obtained from radionuclide angiography by injection of 370-555 MBq 99m Tc-ECD. The first SPECT study was performed immediately after intravenous administration of 1 g of Diamox, then baseline regional cerebral blood flow (rCBF) was calculated using Lassen's correction algorithm. Immediately after the stop of the first SPECT study, additional 555-740 MBq of 99m Tc-ECD was administered, thereafter the second SPECT study was started. Post-Diamox SPECT images were obtained by subtraction of the first baseline images from the second images. Using Lassen's algorithm, post-Diamox mCBF was estimated from the baseline mCBF, the baseline mean SPECT counts, and post-Diamox mean SPECT counts corrected for administered dose and imaging time. Post-Diamox rCBF was obtained from the post-Diamox mCBF and the post-Diamox mean SPECT counts using Lassen's algorithm. Coefficient variation was shown 2.7% and 3.5%: mCBF and rCBF, respectively in test-retest results in six patients without Diamox administration. Nine demented patients without vascular disorders showed significant mCBF increase of 35.7% on the average by post-Diamox. In conclusion, this simplified method is practically useful for measuring CBF at pre- and post-Diamox test within short period of time without any blood sample. (author)

A neutral lipophilic technetium-99m complex for regional cerebral blood flow imaging

International Nuclear Information System (INIS)

Narra, R.K.; Nunn, A.D.; Kuczynski, B.L.; DiRocco, R.J.; Feld, T.; Silva, D.A.; Eckelman, W.C.

1990-01-01

Technetium-99m-DMG-2MP (Chloro[bis[2,3-butanedionedioxime(1-)-0][2,3- butanedionedioximato (2-)-N,N',N double-prime,N'double-prime,N double-prime double-prime,N'double-prime double-prime] (2-methylpropyl borato (2-))technetium]), also known as SQ 32097 is a member of a family of neutral lipophilic compounds generally known as boronic acid adducts of technetium dioxime complexes (BATOs). After i.v. administration, the concentration of [ 99m Tc]DMG-2MP in various regions of the brain appears to be proportional to blood flow. In rats, 1.1% ID was in the brain at 5 min postinjection when the blood contained less than 3% ID. Over 24 hr excretion was 59% in the feces and 23% in the urine. The activity in monkey brain at 5 min was 2.8% ID and it cleared with a t1/2 of 86 min. Autoradiographs of monkey brain sections showed excellent regional detail with a gray/white ratio of 3.6 at 10 min. The distribution of [ 99m Tc]DMG-2MP in the monkey brain corresponds to the known cytoarchitectural pattern of cerebral glucose metabolism. The properties of [ 99m Tc]DMG-2MP make it a potentially useful agent for cerebral perfusion imaging in man

Cerebral blood flow mapping in children with sickle cell disease

International Nuclear Information System (INIS)

Numaguchi, Y.; Humbert, J.R.; Robinson, A.E.; Lindstrom, W.W.; Gruenauer, L.M.

1988-01-01

A cerebral blood flow mapping system was applied to the evaluation of cerebral blood flow (CBF) in 21 patients with sickle cell cerebrovascular disease, by means of a Picker xenon computed tomographic (CT) scanner. Results indicate that (1) xenon CT is a safe and reliable procedure in children with cerebrovascular diseases; (2) CBF in the gray matter of children seems to be higher than in previously reported data obtained with use of isotopes; and (3) regional CBF can be altered significantly by changing the size of the region of interest (ROI). The term regional CBF probably has to be carefully defined in xenon CT flow mapping. Correlation with anatomy by means of CT or magnetic resonance imaging and comparison with the ROI of the contralateral side and/or adjacent sections is important

Anxiety and cerebral blood flow during behavioral challenge. Dissociation of central from peripheral and subjective measures

International Nuclear Information System (INIS)

Zohar, J.; Insel, T.R.; Berman, K.F.; Foa, E.B.; Hill, J.L.; Weinberger, D.R.

1989-01-01

To investigate the relationship between anxiety and regional cerebral blood flow, we administered behavioral challenges to 10 patients with obsessive-compulsive disorder while measuring regional cerebral blood flow with the xenon 133 inhalation technique. Each patient was studied under three conditions: relaxation, imaginal flooding, and in vivo (actual) exposure to the phobic stimulus. Subjective anxiety, obsessive-compulsive ratings, and autonomic measures (heart rate, blood pressure) increased significantly, but respiratory rate and PCO 2 did not change across the three conditions. Regional cerebral blood flow increased slightly (in the temporal region) during imaginal flooding, but decreased markedly in several cortical regions during in vivo exposure, when anxiety was highest by subjective and peripheral autonomic measures. These results demonstrate that intense anxiety can be associated with decreased rather than increased cortical perfusion and that ostensibly related states of anxiety (eg, anticipatory and obsessional anxiety) may be associated with opposite effects on regional cerebral blood flow

Renal cortical and medullary blood flow responses to altered NO availability in humans.

Science.gov (United States)

Damkjær, Mads; Vafaee, Manoucher; Møller, Michael L; Braad, Poul Erik; Petersen, Henrik; Høilund-Carlsen, Poul Flemming; Bie, Peter

2010-12-01

The objective of this study was to quantify regional renal blood flow in humans. In nine young volunteers on a controlled diet, the lower abdomen was CT-scanned, and regional renal blood flow was determined by positron emission tomography (PET) scanning using H(2)(15)O as tracer. Measurements were performed at baseline, during constant intravenous infusion of nitric oxide (NO) donor glyceryl nitrate and after intravenous injection of NO synthase inhibitor N(ω)-monomethyl-L-arginine (L-NMMA). Using the CT image, the kidney pole areas were delineated as volumes of interest (VOI). In the data analysis, tissue layers with a thickness of one voxel were eliminated stepwise from the external surface of the VOI (voxel peeling), and the blood flow subsequently was determined in each new, reduced VOI. Blood flow in the shrinking VOIs decreased as the number of cycles of voxel peeling increased. After 4-5 cycles, blood flow was not reduced further by additional voxel peeling. This volume-insensitive flow was measured to be 2.30 ± 0.17 ml·g tissue(-1)·min(-1) during the control period; it increased during infusion of glyceryl nitrate to 2.97 ± 0.18 ml·g tissue(-1)·min(-1) (P blood flow was 4.67 ± 0.31 ml·g tissue(-1)·min(-1) during control, unchanged by glyceryl nitrate, and decreased after L-NMMA [3.48 ± 0.23 ml·(g·min)(-1), P renal medullary region in which the measured blood flow is 1) low, 2) independent of reduction in the VOI, and 3) reactive to changes in systemic NO supply. The technique seems to provide indices of renal medullary blood flow in humans.

Regional cerebral blood flow in vascular depression assessed by 123I-IMP SPECT

International Nuclear Information System (INIS)

Kimura, Mahito; Shimoda, Kengo; Mizumura, Sunao; Tateno, Amane; Fujito, Tatsuma; Mori, Takao; Endo, Shunkichi

2003-01-01

As the prevalence of white matter hyperintensities detected on T2 weighted MRI scans in patients with late-onset depression is higher than that in nondepressed patients, the concept of ''vascular depression'' (VDep) was introduced in 1997. However, the pathology of vascular depression has not been clarified. This study examined the differences in functional imaging between vascular and non-vascular depression (non-VDep). We utilized 123 I-IMP single photon emission computed tomography (SPECT) to compare regional cerebral blood flows (rCBF) between 9 patients with VDep (Krishnan criteria) and 11 age- and sex-matched patients with non-VDep in both depressed and remitted states. In both VDep and non-VDep patients, mean rCBF increased significantly as depression improved, partially aided by changes in left anterior temporal blood flow. In addition, compared to non-VDep patients, the left anterior frontal rCBF for VDep patients was significantly lower in both depressed and remitted states. Left anterior temporal rCBF therefore appears to represent a state marker that increases as symptoms associated with late-onset depression improve, regardless of vascular changes. Furthermore, in VDep patients, left anterior frontal rCBF was low in both states compared to non-VDep patients, and might not only represent a trait marker, but also correlated with the duration of disease and likelihood of recurrence and relapse. (author)

Brachial blood flow under relative levels of blood flow restriction is decreased in a nonlinear fashion.

Science.gov (United States)

Mouser, J Grant; Ade, Carl J; Black, Christopher D; Bemben, Debra A; Bemben, Michael G

2018-05-01

Blood flow restriction (BFR), the application of external pressure to occlude venous return and restrict arterial inflow, has been shown to increase muscular size and strength when combined with low-load resistance exercise. BFR in the research setting uses a wide range of pressures, applying a pressure based upon an individual's systolic pressure or a percentage of occlusion pressure; not a directly determined reduction in blood flow. The relationship between relative pressure and blood flow has not been established. To measure blood flow in the arm under relative levels of BFR. Forty-five people (18-40 years old) participated. Arterial occlusion pressure in the right arm was measured using a 5-cm pneumatic cuff. Blood flow in the brachial artery was measured at rest and at pressures between 10% and 90% of occlusion using ultrasound. Blood flow decreased in a nonlinear, stepped fashion. Blood flow decreased at 10% of occlusion and remained constant until decreasing again at 40%, where it remained until 90% of occlusion. The decrease in brachial blood flow is not proportional to the applied relative pressure. The prescription of blood flow restriction should take into account the stimulus provided at each relative level of blood flow. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

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

Evaluation of regional cerebral blood flow changes in normal aging using 99mTc-ECD SPECT and Patlak method

International Nuclear Information System (INIS)

Mizuno, Shinji; Nandate, Yuka; Enya, Mayumi; Manabe, Tomoko; Goto, Hiroo; Hoshi, Hiroaki; Takahashi, Yukitoshi; Kato, Zenichiro; Kondo, Naomi

1998-01-01

Changes in regional cerebral blood flow (rCBF) were studied using 99m Tc-ECD SPECT and Patlak method in 47 subjects, aged 1 to 79 years (mean 28.5 years). No abnormal finding was found on MR imaging in the subjects. We obtained mean cerebral blood flow (mCBF) by means of Patlak method. rCBF was measured by positioning regions of interest (ROIs) in frontal lobe, parietal lobe, temporal lobe, occipital lobe, cerebellum and thalamus. The correlation coefficient between ages and mCBF was r=-0.897 (p<0.0001). mCBF of children was significantly higher (p<0.05), compared with adults. By dispersion analysis according to the groups of ages, significantly higher rCBF values were available in the frontal, parietal, temporal and occipital lobes during childhood than adulthood (p<0.05), but there were almost no significant differences of rCBF during childhood than adulthood in cerebellum and thalamus. (author)

In-vivo measurements of regional acetylcholine esterase activity in degenerative dementia: comparison with blood flow and glucose metabolism.

Science.gov (United States)

Herholz, K; Bauer, B; Wienhard, K; Kracht, L; Mielke, R; Lenz, M O; Strotmann, T; Heiss, W D

2000-01-01

Memory and attention are cognitive functions that depend heavily on the cholinergic system. Local activity of acetylcholine esterase (AChE) is an indicator of its integrity. Using a recently developed tracer for positron emission tomography (PET), C-11-labeled N-methyl-4-piperidyl-acetate (C11-MP4A), we measured regional AChE activity in 4 non-demented subjects, 4 patients with dementia of Alzheimer type (DAT) and 1 patient with senile dementia of Lewy body type (SDLT), and compared the findings with measurements of blood flow (CBF) and glucose metabolism (CMRGlc). Initial tracer extraction was closely related to CBF. AChE activity was reduced significantly in all brain regions in demented subjects, whereas reduction of CMRGlc and CBF was more limited to temporo-parietal association areas. AChE activity in SDLT was in the lower range of values in DAT. Our results indicate that, compared to non-demented controls, there is a global reduction of cortical AChE activity in dementia. Dementia, cholinergic system, acetylcholine esterase, positron emission tomography, cerebral blood flow, cerebral glucose metabolism.

Local viscosity distribution in bifurcating microfluidic blood flows

Science.gov (United States)

Kaliviotis, E.; Sherwood, J. M.; Balabani, S.

2018-03-01

The red blood cell (RBC) aggregation phenomenon is majorly responsible for the non-Newtonian nature of blood, influencing the blood flow characteristics in the microvasculature. Of considerable interest is the behaviour of the fluid at the bifurcating regions. In vitro experiments, using microchannels, have shown that RBC aggregation, at certain flow conditions, affects the bluntness and skewness of the velocity profile, the local RBC concentration, and the cell-depleted layer at the channel walls. In addition, the developed RBC aggregates appear unevenly distributed in the outlets of these channels depending on their spatial distribution in the feeding branch, and on the flow conditions in the outlet branches. In the present work, constitutive equations of blood viscosity, from earlier work of the authors, are applied to flows in a T-type bifurcating microchannel to examine the local viscosity characteristics. Viscosity maps are derived for various flow distributions in the outlet branches of the channel, and the location of maximum viscosity magnitude is obtained. The viscosity does not appear significantly elevated in the branches of lower flow rate as would be expected on the basis of the low shear therein, and the maximum magnitude appears in the vicinity of the junction, and towards the side of the outlet branch with the higher flow rate. The study demonstrates that in the branches of lower flow rate, the local viscosity is also low, helping us to explain why the effects of physiological red blood cell aggregation have no adverse effects in terms of in vivo vascular resistance.

Cluster headache: transcranial Doppler ultrasound and regional cerebral blood flow studies

International Nuclear Information System (INIS)

Dahl, A.; Russell, D.; Nyberg-Hansen, R.; Rootwelt, K.

1990-01-01

Transcranial Doppler and rCBF examinations were carried out in 25 cluster headache patients. Spontaneous glyceryl trinitrate (nitroglycerin) provoked attacks were accompanied by a bilateral decrease in middle cerebral artery blood flow velocities. This decrease was more pronounced on the symptomatic side, but the difference did not reach statistical significance. Mean hemispheric blood flow and rCBF were within normal limits during provoked attacks and similar to those found when patients were attack-free. During cluster periods middle cerebral artery velocities were significantly higher on the symptomatic side. Glyceryl trinitrate caused a bilateral middle cerebral artery velocity decrease which was significantly greater on the symptomatic side. Attacks provoked by glyceryl trinitrate appeared to begin when the vasodilatory effect of this substance was received. 17 refs., 2 figs., 5 tabs

Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

Energy Technology Data Exchange (ETDEWEB)

Clanet, M

1987-06-18

Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO/sub 2/), oxygen extraction (EO/sub 2/) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO/sub 2/ and often a decrease in CMRO/sub 2/, whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO/sub 2/, EO/sub 2/ and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis.

Value of cerebral blood flow rate and regional oxygen consumption studies in cerebral ischaemia

International Nuclear Information System (INIS)

Clanet, M.

1987-01-01

Studies of experimentally-induced ischaemia have shown that the intensity of neuronal suffering is related to the fall in perfusion rate. Below a certain level, called functional threshold, cerebral function is reversibly altered, whereas at a lower level (tissue necrosis threshold) the damage inflicted on neurons is irreversible. Between these two thresholds lies a ''penumbra zone''. This concept of thresholds must be mitigated by 2 parameters: duration of ischaemia and selective vulnerability of the various structures affected. Variations in blood flow rate only indirectly affect the state of tissues. Techniques developed from positron emission tomography make it possible to evaluate the metabolic activity of brain tissue in vivo: oxygen consumption (CMRO 2 ), oxygen extraction (EO 2 ) and glucose consumption (CMRG) which are thus correlated to cerebral blood flow and cerebral blood volume, sometimes also to tissue pH. Normal relations between blood flow rate and metabolism may be altered. Misery perfusion reflects a fall in cerebral blood flow with an increase in EO 2 and often a decrease in CMRO 2 , whereas luxury perfusion reflects an increase in cerebral blood flow rate with reduction of CMRO 2 , EO 2 and CMRG. The type of alteration encountered in human ischaemia varies according to the nature of the accident: studies of transient accidents emphasize the different haemodynamic aspects of occlusion of the wider arteries. The metabolic and haemodynamic profiles of established ischaemic accidents vary according to their type and to the time of the study, reflecting the complexity of the physiopathological mechanisms involved; they are frequently associated with metabolic repercussions at a distance from the ischaemic focus, which supports the concept of diaschisis [fr

Evaluation and investigation of regional cerebral blood flow by 1 point arterial blood collection method using 99mTc-ECD. Intravenous injection for 4 minutes with constant speed

International Nuclear Information System (INIS)

Itoh, Takeo; Shibata, Kazuhiro; Sudoh, Hideaki; Tanaka, Masato; Itoh, Kenjiro; Ueno, Yasushi

1998-01-01

Regional cerebral blood flow (rCBF) was measured using a 99m Tc-ECD through the 4-min constant intravenous infusion/one point arterial blood sampling method, proposed by Nakagawara et al. of Nakamura Memorial Hospital, and 133Xenon ( 133 Xe)-SPECT was performed on the same subjects to investigate the reproducibility of this method. We also determined whether cerebral blood flow (CBF) could be measured on the day of blood sampling through dilution of the obtained blood because it was difficult to measure the radioactivity in the blood on the day of blood sampling by this method. More, we investigated fixation of an octanol extraction rate and the substitution of venous blood for arterial blood in this method. The results revealed that CBF measured by this method with a 99m Tc-ECD were closely correlated to those measured by 133 Xe-SPECT, indicating the reliability as a method of measuring CBF. rCBF could be measured on the day of blood sampling through appropriate dilution of the obtained arterial blood. Octanol extraction rates were almost constant, indicating possible omission of cumbersome extraction procedure by fixation. However, the substitution of venous blood for arterial blood showed no correlation under the study system examined. (author)

Physiological activation of the human cerebral cortex during auditory perception and speech revealed by regional increases in cerebral blood flow

DEFF Research Database (Denmark)

Lassen, N A; Friberg, L

1988-01-01

by measuring regional cerebral blood flow CBF after intracarotid Xenon-133 injection are reviewed with emphasis on tests involving auditory perception and speech, and approach allowing to visualize Wernicke and Broca's areas and their contralateral homologues in vivo. The completely atraumatic tomographic CBF...

Role of blood flow and blood flow modifiers in clinical hyperthermia therapy

International Nuclear Information System (INIS)

Olch, A.J.

1986-01-01

A quantitative assessment of the effect of localized magnetic-loop hyperthermia on blood flow was performed on 12 patients (19 tumor studies) using the Xenon-133 clearance method. After it was discovered that blood flow in most of the tumors increased in response to needle injection, a physiologically based, one compartment model was developed that included both a hyperemic (transient) and a steady state component. In the tumors of six patients, increases in blood flow induced by heat were also observed. The same model was used to describe the measured clearance data for both types of hyperemic response. The ability of tumor vessels to respond dynamically to stress and the degree of response may be predictive of tumor heating efficiency and subsequent therapeutic response. Many tumors treated by hyperthermia, therefore, do not reach therapeutic temperatures (42 0 C). One explanation for this may be that some tumors react to thermal stress in a manner similar to normal tissues; i.e., they increase blood flow during hyperthermia in order to dissipate heat. Higher temperatures might be achieved in these heat-resistant tumors by administering vasoconstrictive agents in an effort to reduce blood flow. In the second part of this research study, the extent to which pharmacologic inhibition of local blood flow might allow higher temperatures to develop in normal muscles exposed to localized radiofrequency hyperthermia was determined. It was found that the local muscle temperature rise could be increased by at least 90% in dogs and rabbits with the use of a local vasoconstrictive drug

Effect of Body Temperature on the Radionuclide Evaluation of Cerebral Blood Flow

International Nuclear Information System (INIS)

Mustafa, S. . E- mail: seham@hsc.edu.kw; Elgazzar, A.H.; Gopinath, S.; Mathew, M.; Khalil, M.

2006-01-01

Changes in regional cerebral blood flow (rCBF) may reflect physiological correlates of the disease state. In neuro-imaging studies, some diseases have frequently been reported to be associated with reduced or increased rCBF. In a previous study we had shown evidence of heat induced vasoconstriction of the carotid artery, which is the main vessel supplying blood to the brain. This vasoconstriction may lead to a decrease in cerebral blood flow in hyperthermic patients. Most radionuclide studies used to assess cerebral blood flow are routinely performed without taking into consideration patients' body temperature. In this regard it may be noted that results of radionuclide cerebral perfusion studies may be affected by hyperthermia, which could lead to false positive studies or misinterpretation of results when they are performed on patients suffering from various cerebrovascular diseases. The objective of the present study was to investigate the importance of body temperature and its effect on the results of radionuclide cerebral perfusion studies. Cerebral blood flow was assessed using Tc-99m hexamethylpropyleneamineoxime (Tc-99m HMPAO) imaging. Baseline scintigraphic images of the brain were obtained in 10 rabbits using a gamma camera equipped with a low energy parallel hole and high resolution collimator interfaced with a computer. Repeat brain studies were performed on the same rabbits at 3 and 6 days after raising the body temperature by 2 deg. C and 4 deg. C respectively using the same imaging protocol. The counts per pixel were determined on control and hyperthermia images. The uptake of Tc-99m HMPAO in the brain was found to be significantly reduced following hyperthermia implying reduction in blood flow. This decrease in cerebral perfusion appears to be variable from region to region, being more in the cerebral hemispheres, frontal areas (olfactory lobes) than in the cerebellum. Based on the results, the authors conclude that a rise in body temperature might

Regional cerebral blood flow measurement using N-isopropyl-p-[123I] iodoamphetamine and rotating gamma camera emission computed tomography

International Nuclear Information System (INIS)

Matsuda, Hiroshi; Seki, Hiroyasu; Ishida, Hiroko

1985-01-01

Thirty-one regional cerebral blood flow (rCBF) measurements were performed on 26 patients with cerebrovascular accidents using N-Isopropyl-p-[ 123 I] Iodoamphetamine ( 123 I-IMP) and rotating gamma camera emission computed tomography (ECT). The equation for determining rCBF is as follows: F=100.R.Cb/(N.A), where F is rCBF in ml/100 g/min., R is the constant withdrawal rate of arterial blood in ml/min., Cb is the brain activity concentration in μCi/g, A is the total activity (5 min.) in the withdrawal arterial whole blood in μCi and N is the fraction of A that is true tracer activity (0.75). In determining Cb at 5 min. after injection, reconstructed counts from 35 min. to 59 min. were corrected to represent those from 4 min. to 5 min. with the use of time activity curve for the entire brain immediately after injection to 30 min. Reconstructed counts of central region in tomographic image were corrected 118% of the obtained values from the result of the countingrate ratio between peripheral and central regions of interests obtained from phantom study. Brain mean blood flow values were distributed from 11 to 39 ml/100 g/min. In 119 cortical regions obtained from 11 measurements in 9 patients, there was a significant correlation (r=0.41, p 123 I-IMP and rotating gamma camera ECT and those from 133 Xe inhalation method. rCBF measurement using 123 I-IMP and rotating gamma camera ECT is not only relatively noninvasive measurement for the entire brain but also three-dimensional evaluation. Besides, it is superior in spatial resolution and accuracy to conventional 133 Xe clearance method. (author)

Regional cerebral blood flow using sup 133 Xenon intra-venous technique, 2; Evaluation of regional cerebral blood flow in patients with cerebrovascular ischemic disease

Energy Technology Data Exchange (ETDEWEB)

Yonekura, Masahiro; Teramoto, Shigeyoshi; Moriyama, Tadayoshi (Nagasaki Chuo National Hospital (Japan))

1990-12-01

Using the {sup 133}Xenon venous method, we have studied the regional cerebral blood flow (rCBF) in 947 patients with cerebrovascular ischemic disease. In 116 stroke or TIA patients with internal carotid artery occlusion or severe stenosis, their rCBF revealed 48.9 ml/100 g/min on average in the group of one side occlusion, 46.7 ml/100 g/min in the group of both sides occlusion. These values reduced approximately 12%, 16% and 15% of the rCBF in healthy volunteers of same age, respectively. In 28 patients with moya moya disease, their rCBF tended to be higher in younger cases and lower with advanced age. In the majority of the cases, their rCBF was age-dependent with 20{similar to}25 ml/100 g/min below the curve of age-matched rCBF of healthy volunteers. The reduction of rCBF was observed in 69 (48.3%) of 143 cases clinically diagnosed as small vessel disease, in 58 (41.4%) of 140 cases with vertebro-basilar insufficiency and in 23 (44.2%) of 52 cases with syncopal attack compared with the rCBF of healthy volunteers. (author).

Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs

DEFF Research Database (Denmark)

Sandgaard, N C F; Andersen, J L; Holstein-Rathlou, N-H

2002-01-01

We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven...... arterial blood pressure by 49% and decreased TRBF by 12%, providing an increase in renal vascular resistance of 69%. Dynamic analysis showed autoregulation of renal blood flow in the frequency range ... of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta....

The Physics of Coronary Blood Flow

CERN Document Server

Zamir, M

2005-01-01

Coronary blood flow is blood flow to the heart for its own metabolic needs. In the most common form of heart disease there is a disruption in this flow because of obstructive disease in the vessels that carry the flow. The subject of coronary blood flow is therefore associated mostly with the pathophysiology of this disease, rarely with dynamics or physics. Yet, the system responsible for coronary blood flow, namely the "coronary circulation," is a highly sophisticated dynamical system in which the dynamics and physics of the flow are as important as the integrity of the conducting vessels. While an obstruction in the conducting vessels is a fairly obvious and clearly visible cause of disruption in coronary blood flow, any discord in the complex dynamics of the system can cause an equally grave, though less conspicuous, disruption in the flow. This book is devoted specifically to the dynamics and physics of coronary blood flow. While relevance to the clinical and pathophysiological issues is clearly maintaine...

Simple technique for measuring relative renal blood flow

International Nuclear Information System (INIS)

Shames, D.M.; Korobkin, M.

1976-01-01

To determine whether externally monitored early renal uptake of 131 I-hippurate is proportional to renal blood flow, the renal uptake of 131 -hippurate at 1 to 2 min after injection was compared with the renal accumulation of radioactive carbonized microspheres in dogs. A renal artery catheter equipped with a balloon was used to decrease renal blood flow unilaterally. One minute after the intravenous injection of 100 μCi of 131 I-hippurate, about 1 μCi of either 85 Sr- or 95 Nb-labeled carbon microspheres was injected into the left ventricle. Radioactivity was measured over both kidneys. The total radioactivity within each kidney region of interest was corrected for background and integrated over the 1 to 2 min interval after injection. Thirteen measurements of relative renal blood flow were made for seven dogs. The dogs were then killed and both kidneys were excised and counted for the radioactivity of the microspheres. The 1 to 2-min relative renal uptake of 131 I-hippurate correlated well with relative microsphere uptake, suggesting that relative renal blood flow can be simply determined from the external measurements of renal uptake of 131 I-hippurate

Correlations between regional cerebral blood flow and age-related brain atrophy: a quantitative study with computed tomography and the xenon-133 inhalation method

International Nuclear Information System (INIS)

Yamaguchi, T.; Hatazawa, J.; Kubota, K.; Abe, Y.; Fujiwara, T.; Matsuzawa, T.

1983-01-01

One hundred and two subjects (40 men and 62 women) neither having a history of neurologic deficits nor showing organic lesions on computed tomographic examination of the brain were studied. Ages of the subjects ranged from 26 to 81 years. Regional cerebral blood flow was measured by the xenon-133 inhalation method, and the volume percentage of brain with respect to the cranial cavity (craniocerebral index) was calculated by means of computer programs. Regional cerebral blood flow was computed as the fast component of two-compartmental analysis and as the initial slope index value. The percentage of each subject's craniocerebral index in relation to the standard for subjects with non-atrophied brains (brain volume index) was calculated as the indicator of brain atrophy. Both the mean brain fast component values and the mean brain initial slope index values correlated closely with the brain volume index in the elderly. Low cerebral blood flow values coincided with loss of brain substance in the final stage of age-related brain atrophy, but not in the intermediate stage

Validation of transit-time flowmetry for chronic measurements of regional blood flow in resting and exercising rats

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S.L. Amaral

1997-07-01

Full Text Available The objective of the present study was to validate the transit-time technique for long-term measurements of iliac and renal blood flow in rats. Flow measured with ultrasonic probes was confirmed ex vivo using excised arteries perfused at varying flow rates. An implanted 1-mm probe reproduced with accuracy different patterns of flow relative to pressure in freely moving rats and accurately quantitated the resting iliac flow value (on average 10.43 ± 0.99 ml/min or 2.78 ± 0.3 ml min-1 100 g body weight-1. The measurements were stable over an experimental period of one week but were affected by probe size (resting flows were underestimated by 57% with a 2-mm probe when compared with a 1-mm probe and by anesthesia (in the same rats, iliac flow was reduced by 50-60% when compared to the conscious state. Instantaneous changes of iliac and renal flow during exercise and recovery were accurately measured by the transit-time technique. Iliac flow increased instantaneously at the beginning of mild exercise (from 12.03 ± 1.06 to 25.55 ± 3.89 ml/min at 15 s and showed a smaller increase when exercise intensity increased further, reaching a plateau of 38.43 ± 1.92 ml/min at the 4th min of moderate exercise intensity. In contrast, exercise-induced reduction of renal flow was smaller and slower, with 18% and 25% decreases at mild and moderate exercise intensities. Our data indicate that transit-time flowmetry is a reliable method for long-term and continuous measurements of regional blood flow at rest and can be used to quantitate the dynamic flow changes that characterize exercise and recovery

Regional cerebral blood flow using 133Xenon intra-venous technique, 1

International Nuclear Information System (INIS)

Yonekura, Masahiro; Teramoto, Shigeyoshi; Moriyama, Tadayoshi

1990-01-01

We used the noninvasive 133 Xenon venous technique to measure 3622 regional cerebral blood flows (rCBFs) in 1955 cases for last about six years. The majority of patients was in their fifties or sixties, and their diagnosis was ischemic cerebrovascular disease. Sixty-four healthy, non-hospitalized volunteers (10∼76 years) were studied as control value. The age-related curve of rCBF showed a rapid decrease in young age groups and a gradual decrease in older age groups. The curve was well fitted to the hyperbola (X-13.0621)(Y-42.6038)=556.493. The correlation coefficient was 0.93. This finding showed that the declined rCBF related with age was attributed to more than two factors. When cerebrovascular CO 2 reactivity was tested in the healthy control group, the rCBF on average increased to 90.5 ml/100 g/min from 70.2 ml/100 g/min (28.9%) being accompanied with the elevation of Pco 2 of 11.4 mmHg in arterial blood gas on average. The CO 2 reactivity index was 2.75 ± 1.65 on average. On the other hand, following an intravenous injection of Diamox (1 g) the rCBF increased to 80.0 ml/100 g/min from 59.6 ml/100 g/min (34.2%) on average in the control group. (author)

Regional cerebral blood flow during rest and skilled hand movements by xenon-133 inhalation and emission computerized tomography

DEFF Research Database (Denmark)

Lauritzen, M; Henriksen, L; Lassen, N A

1981-01-01

Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating ("dynamic"), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1...... motor area on both sides by 34 +/- 15% (p less than 0.025)....

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

Assessment of changes in regional cerebral blood flow in patients with major depression using the 99mTc-HMPAO single photon emission tomography method

International Nuclear Information System (INIS)

Yazici, K.; Kapucu, Oe.; Erbas, B.; Varoglu, E.; Guelec, C.; Bekdik, C.F.; Hacettepe Univ., Ankara

1992-01-01

Regional cerebral blood flow was investigated in 14 patients with major depression diagnosed according to the DSM-III-R criteria (six patients with single and eight patients with recurrent episodes) and in ten healthy volunteers. The mean ages of the patients and the controls were 33.5±2.7 and 31.6±2.6 years, respectively. The severity of the depression was assessed using the 17-item Hamiltonian Depression Scale (mean: 23.2±1.5). None of the patients was under medication. After administration of 500 MBq technetium-99m hexamethylpropylene amine oxime, a single photon emission tomography study was performed and then transaxial, sagittal and coronal slices were obtained. For the semiquantitative analysis of the data, the ratios of the mean counts/pixel to the whole slice were calculated for 24 regions on three consecutive transaxial slices in the orbitomeatal plane. Additionally, left/right and frontal/occipital ratios were calculated. Both sides of the temporal region had a significantly decreased cerebral blood flow (CBF) when compared to the controls. The left/right ratio of the prefrontal region was also significantly lower in the patients than in the controls. The Hamilton score had a negative correlation with blood flow in the anterofrontal and left prefrontal regions. According to our results, regional CBF seems to be decreased in the left prefrontal and in both temporal regions in major depression. The severity of depression is correlated with the reduction in CBF in the regions of the anterofrontal and left prefrontal cortex. (orig.)

Radionuclide study on hepatic blood flow in Schistosomiasis Japonica

Energy Technology Data Exchange (ETDEWEB)

Okada, Junichi; Uchiyama, Guio; Hayakawa, Kazushige; Hayashi, Sanshin; Araki, Tsutomu; Arai, Takao; Iuchi, Masahiko

1986-11-01

Schistosomiasis Japonica is a regional disease found in elderly people who were living in once-endemic areas in Japan. Yamanashi was one of these areas until 1970, since when no newly infected patients were reported. The disease is characteristic of developing irreversible interstitial fibrosis of the liver, where parasites migrate and lay eggs. Portal hypertension, esophageal varices and hepatocellular carcinomas are the common features of the results. In order to estimate patient's hepatic blood flow, radionuclide angiography of the liver with the use of 10 - 15 millicuries of Tc-99m phytate were performed prior to the conventional multiview imaging. Twenty-two patients with schistosomiasis and twelve adults without evidence of liver disease were studied. A time-activity curve of the right lobe of the liver was generated by a computer, and the ratio of arterial blood flow to portal blood flow was calculated. As a result, a good correlation was found between the arterial to portal blood flow ratio and the grade of hepatic fibrosis verified by laparoscopic biopsy. The development of esophageal varices were likely to correlate well with the blood flow ratio rather than scores on the conventional static liver and spleen scintigram. The study was useful for evaluating patient's clinical stages and prognosis.

Radionuclide study on hepatic blood flow in Schistosomiasis Japonica

International Nuclear Information System (INIS)

Okada, Junichi; Uchiyama, Guio; Hayakawa, Kazushige; Hayashi, Sanshin; Araki, Tsutomu; Arai, Takao; Iuchi, Masahiko.

1986-01-01

Schistosomiasis Japonica is a regional disease found in elderly people who were living in once-endemic areas in Japan. Yamanashi was one of these areas until 1970, since when no newly infected patients were reported. The disease is characteristic of developing irreversible interstitial fibrosis of the liver, where parasites migrate and lay eggs. Portal hypertension, esophageal varices and hepatocellular carcinomas are the common features of the results. In order to estimate patient's hepatic blood flow, radionuclide angiography of the liver with the use of 10 - 15 millicuries of Tc-99m phytate were performed prior to the conventional multiview imaging. Twenty-two patients with schistosomiasis and twelve adults without evidence of liver disease were studied. A time-activity curve of the right lobe of the liver was generated by a computer, and the ratio of arterial blood flow to portal blood flow was calculated. As a result, a good correlation was found between the arterial to portal blood flow ratio and the grade of hepatic fibrosis verified by laparoscopic biopsy. The development of esophageal varices were likely to correlate well with the blood flow ratio rather than scores on the conventional static liver and spleen scintigram. The study was useful for evaluating patient's clinical stages and prognosis. (author)

Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)

International Nuclear Information System (INIS)

Ichiseki, Hajime; Terashi, Akiro; Hamamoto, Makoto; Miyazaki, Tokuzo.

1995-01-01

We have performed single photon emission computed tomography (SPECT) with 99m Tc-hexamethylpropylene amineoxime (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in status epileptics (SE) caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in radio isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular diseases, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEC but also SPECT scans when making a diagnosis of SE. (author)

Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)

Energy Technology Data Exchange (ETDEWEB)

Ichiseki, Hajime; Terashi, Akiro [Nippon Medical School, Tokyo (Japan); Hamamoto, Makoto; Miyazaki, Tokuzo

1995-12-01

We have performed single photon emission computed tomography (SPECT) with {sup 99m}Tc-hexamethylpropylene amineoxime (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in status epileptics (SE) caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in radio isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular diseases, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEC but also SPECT scans when making a diagnosis of SE. (author).

Repeatability of regional myocardial blood flow calculation in 82Rb PET imaging

International Nuclear Information System (INIS)

Knešaurek, Karin; Machac, Josef; Zhang, Zhuangyu

2009-01-01

We evaluated the repeatability of the calculation of myocardial blood flow (MBF) at rest and pharmacological stress, and calculated the coronary flow reserve (CFR) utilizing 82 Rb PET imaging. The aim of the research was to prove high repeatability for global MBF and CFR values and good repeatability for regional MBF and CFR values. The results will have significant impact on cardiac PET imaging in terms of making it more affordable and increasing its use. 12 normal volunteers were imaged at rest and during pharmacological stress, with 2220 MBq of 82 Rb each. A GE Advance PET system was used to acquire dynamic 50-frame studies. MBF was calculated with a 2-compartmental model using a modified PMOD program (PMOD; University Hospital Zurich, Zurich, Switzerland). Two differential equations, describing a 2-compartmental model, were solved by numerical integration and using Levenberg-Marquardt's method for fitting data. The PMOD program defines 16 standard segments and calculates myocardial flow for each segment, as well as average septal, anterior, lateral, inferior and global flow. Repeatability was evaluated according to the method of Bland and Altman. Global rest and stress MBF, as well as global CFR, showed very good repeatability. No significant differences were found between the paired resting global MBF (0.63 ± 0.13 vs. 0.64 ± 0.13 mL/min/g; mean difference, -1.0% ± 2.6%) and the stress global MBF (1.37 ± 0.23 vs. 1.37 ± 0.24; mean difference, 0.1% ± 2.3%). Global CFR was highly reproducible (2.25 ± 0.56 vs. 2.22 ± 0.54, P = not statistically significant; mean difference, 1.3% ± 14.3%). Repeatability coefficients for global rest MBF were 0.033 (5.2%) and stress MBF 0.062 (4.5%) mL/min/g. Regional rest and stress MBF and CFR have shown good reproducibility. The average per sector repeatability coefficients for rest MBF were 0.056 (8.5%) and stress MBF 0.089 (6.3%) mL/min/g, and average repeatability coefficient for CFR was 0.25 (10.6%). The results

Determinants of pulmonary blood flow distribution.

Science.gov (United States)

Glenny, Robb W; Robertson, H Thomas

2011-01-01

The primary function of the pulmonary circulation is to deliver blood to the alveolar capillaries to exchange gases. Distributing blood over a vast surface area facilitates gas exchange, yet the pulmonary vascular tree must be constrained to fit within the thoracic cavity. In addition, pressures must remain low within the circulatory system to protect the thin alveolar capillary membranes that allow efficient gas exchange. The pulmonary circulation is engineered for these unique requirements and in turn these special attributes affect the spatial distribution of blood flow. As the largest organ in the body, the physical characteristics of the lung vary regionally, influencing the spatial distribution on large-, moderate-, and small-scale levels. © 2011 American Physiological Society.

Emesis, radiation exposure, and local cerebral blood flow in the ferret

International Nuclear Information System (INIS)

Tuor, U.I.; Kondysar, M.H.; Harding, R.K.

1988-01-01

We examined the sensitivity of the ferret to emetic stimuli and the effect of radiation exposure near the time of emesis on local cerebral blood flow. Ferrets vomited following the administration of either apomorphine (approx 45% of the ferrets tested) or peptide YY (approx 36% of those tested). Exposure to radiation was a very potent emetic stimulus, but vomiting could be prevented by restraint of the hindquarters of the ferret. Local cerebral blood flow was measured using a quantitative autoradiographic technique and with the exception of several regions in the telencephalon and cerebellum, local cerebral blood flow in the ferret was similar to that in the rat. In animals with whole-body exposure to moderate levels of radiation (4 Gy of 137 Cs), mean arterial blood pressure was similar to that in the control group. However, 15-25 min following irradiation there was a general reduction of local cerebral blood flow ranging from 7 to 33% of that in control animals. These cerebral blood flow changes likely correspond to a reduced activation of the central nervous system

Cerebral blood flow measurement in cerebrovascular occlusive diseases

International Nuclear Information System (INIS)

Yanagihara, T.; Wahner, H.W.

1984-01-01

In order to evaluate cerebral blood flow (CBF) patterns among individual patients with increased statistical confidence, CBF measurements were carried out using the 133Xe-inhalation method and external head detectors. F1 values representing gray matter flow from 3 to 6 head detectors were averaged to form 16 different regions for each cerebral hemisphere. Normative values were obtained from 46 healthy volunteers, and data from individual regions were analyzed for absolute blood flow rates (ml/100g/min), for concordance between right and left hemispheres and as percent of mean hemispheric flow. CBF measurements were then carried out among 37 patients with cerebrovascular occlusive diseases, and results were compared with normative values. A high incidence of abnormal flows were detected among symptomatic patients with intracranial arterial stenosis or occlusion and those with extracranial internal carotid artery occlusion. By using the above method for data analysis, it was possible to delineate hypoperfused areas among these patients. Even though the 133Xe-inhalation method has inherent limitations, this is a practical and safe method for measurement of CBF which can provide reliable information useful for management of patients with cerebrovascular occlusive diseases, particularly when the results are presented with statistical confidence

Sex-dependent alterations in resting-state cerebral blood flow, amplitude of low-frequency fluctuations and their coupling relationship in schizophrenia.

Science.gov (United States)

Ma, Xiaomei; Wang, Di; Zhou, Yujing; Zhuo, Chuanjun; Qin, Wen; Zhu, Jiajia; Yu, Chunshui

2016-04-01

We aimed to investigate sex-dependent alterations in resting-state relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling in patients with schizophrenia. Resting-state functional magnetic resonance imaging and three-dimensional pseudo-continuous arterial spin labeling imaging were performed to obtain resting-state amplitude of low-frequency fluctuations and relative cerebral blood flow in 95 schizophrenia patients and 99 healthy controls. Sex differences in relative cerebral blood flow and amplitude of low-frequency fluctuations were compared in both groups. Diagnostic group differences in relative cerebral blood flow, amplitude of low-frequency fluctuations and relative cerebral blood flow-amplitude of low-frequency fluctuations coupling were compared in male and female subjects, respectively. In both healthy controls and schizophrenia patients, the males had higher relative cerebral blood flow in anterior brain regions and lower relative cerebral blood flow in posterior brain regions than did the females. Compared with multiple regions exhibiting sex differences in relative cerebral blood flow, only the left middle frontal gyrus had a significant sex difference in amplitude of low-frequency fluctuations. In the females, schizophrenia patients exhibited increased relative cerebral blood flow and amplitude of low-frequency fluctuations in the basal ganglia, thalamus and hippocampus and reduced relative cerebral blood flow and amplitude of low-frequency fluctuations in the frontal, parietal and occipital regions compared with those of healthy controls. However, there were fewer brain regions with diagnostic group differences in the males than in the females. Brain regions with diagnostic group differences in relative cerebral blood flow and amplitude of low-frequency fluctuations only partially overlapped. Only the female patients exhibited increased relative cerebral

Pulmonary and systemic blood flow contributions to upper airways in canine lung

International Nuclear Information System (INIS)

Barman, S.A.; Ardell, J.L.; Parker, J.C.; Perry, M.L.; Taylor, A.E.

1988-01-01

The blood flow contributions and drainage patterns of the pulmonary and systemic circulations in the upper airways (trachea and main bronchi) were assessed in anesthetized dogs by injecting 15-μm radiolabeled microspheres into the right and left heart, respectively. After the animals were killed, the tracheal cartilage, tracheal muscle-mucosa, and main bronchi were excised. The tracheal cartilage and tracheal muscle-mucosa were divided into lower, middle, and upper segments for blood flow determinations. The pulmonary contribution to tracheal blood flow was very small, being higher in the lower segments. The systemic contribution to these same tracheal regions was significantly higher, and higher in the upper segments. The pulmonary and systemic circulations each contributed ∼50% to the main bronchi blood flow. The pulmonary blood flow contribution alone to the trachea and main bronchi was also determined in subsequent experiments that utilized the isolated lung, and these blood flows were not significantly different from the pulmonary contribution measured in the intact lungs. The present results indicate that the systemic (bronchial) circulation is the primary source of tracheal blood flow and that both the pulmonary and systemic circulations may contribute ∼50% of the blood flow to the main bronchi in dog lungs

Regional cerebral blood flow in various pediatric neurological patients using 123I-IMP SPECT

International Nuclear Information System (INIS)

Konishi, Tohru; Naganuma, Yoshihiro; Hongou, Kazuhisa; Murakami, Miyako; Yamatani, Miwa; Okada, Toshio

1988-01-01

The recent development of a new radiopharmaceutical 123 I-isopropyl-iodoamphetamine (IMP), which is taken up by the brain from the blood flow, has offered a possibility of constructing scintigraphy maps of regional cerebral blood flow (rCBF) using single photon emission CT. We used this mehtod in various pediatric neurological diseases. Six patients with cerebro-vascular disorders (moya-moya disease 2, infarction 3 and HHE syndrome 1), 6 patients with infectious diseases of CNS (acute encephalitis 4, septic meningitis 1 and SSPE 1) and a miscellaneous group of six patients were studied. The rCBF abnormalities in cerebro-vascular diseases were more extensive and frequent than x-ray CT abnormalities. Repeated studies of IMP-SPECT revealed usefulness for the understanding of changeable hemodynamic pathophysiology and for the judgment of theraptic effectiveness and prognosis. The rCBF decrease in infectious diseases tended to be more diffuse and slight than that in cerebro-vascular diseases. In almost all patients, the area of rCBF decrease coincided with the area of EEG slowing evaluated by EEG topographic analysis. Brain imaging using 123 I-IMP SPECT may reveal functional abnormalities as well as organic lesions. 123 I-IMP SPECT has introduced a new era for the useful application of nuclear medicine to the investigation of pediatric neurological diseases. (author)

Regional cerebral blood flow analysis of vascular dementia by the single photon emission computed tomography

International Nuclear Information System (INIS)

Miyakawa, Kouichi; Watanabe, Sho; Suzuki, Michiyo; Kamijima, Gonbei

1989-01-01

In order to evaluate the relationship between the regional cerebral blood flow (CBF) and cerebrovascular dementia, eleven patients with vascular dementia and eight patients with non-demented infarction were studied and regional CBF were measured quantitatively with single photon emission computed tomography (SPECT) by using N-isopropyl-p-(I-123) iodoamphetamine. All cases were basal infarction and vascular dementia were diagnosed by less than 21.5 of the Hasegawa's dementia score and more than 7 of Hachinsk's ischemic score. The results of the present study were as follows: (1) Cerebrovascular dementia showed lower mean CBF value compared with non-demented group. (2) Regional CBF of bilateral frontal areas and affected basal ganglia were significantly reduced than occipital area in the dementia group. (3) A comparison of regional CBF and the Hasegawa's dementia score revealed a statistically significant correlation at the bilateral frontal areas in the dementia group. It is possible that measuring the regional CBF quantitatively by IMP-SPECT is useful for clinical analysis of vascular dementia. (author)

Regional cerebral blood flow for singers and nonsingers while speaking, singing, and humming a rote passage

International Nuclear Information System (INIS)

Formby, C.; Thomas, R.G.; Halsey, J.H. Jr.

1989-01-01

Two groups of singers (n = 12,13) and a group of nonsingers (n = 12) each produced the national anthem by (1) speaking and (2) singing the words and by (3) humming the melody. Regional cerebral blood flow (rCBF) was measured at rest and during each phonation task from seven areas in each hemisphere by the 133 Xe-inhalation method. Intrahemisphere, interhemisphere, and global rCBF were generally similar across phonation tasks and did not yield appreciable differences among the nonsingers and the singers

Assessment of pancreatic blood flow with positron emission tomography and oxygen-15 water

International Nuclear Information System (INIS)

Kubo, Soichi; Yamamoto, Kazutaka; Magata, Yasutaka; Iwasaki, Yasushi; Tamaki, Nagara; Yonekura, Yoshiharu; Konishi, Junji

1991-01-01

Dynamic positron emission tomography (PET) was performed following an intravenous bolus injection of 15 O-water for the assessment of regional pancreatic blood flow in 4 normal volunteers and 11 patients with pancreatic cancer. The regional pancreatic blood flow index (PFI) was calculated by the autoradiographic method assuming the time-activity curves of the aorta as an input function. The mean PFI value was 0.514±0.098 in the normal pancreas but it was decrease in the pancreatic cancer (0.247±0.076) (p 15 O-water permits quantitative assessment of pancreatic blood flow which decreased in both pancreatic cancer and concomitant obstructive pancreatitis distal to the tumor. (author)

Semiquantifying regional cerebral blood flow by dynamic CT scanning

International Nuclear Information System (INIS)

Takeuchi, Totaro; Kasahara, Eishi; Takahashi, Eriko; Kojima, Seiichi; Ogawa, Haruhiko; Suzuki, Keiko; Miyamae, Tatsuya; Yamazaki, Setsuo.

1990-01-01

The study was undertaken to evaluate the semi-quantitative significance of the absolute value obtained by calculating the regional cerebral blood flow index (rCBFI) from dynamic CT in comparison with SPECT. rCBFI was calculated from mean transit time (MTT) and blood capacity index (BCI) obtained by rapidly infusing 50 ml of Omnipurk into the elbow vein by the use of Hitachi's W-600. [rCBFI=BCI/MTT unit/sec (U/S)] measurment of the rCBF by SPECT was made according to the semi-quantitative method by Matsuda et al. by the use of SHIMADZU's improved type HEADTOME SET-050 with rapid infusion of 123 I-IMP in 3.5 m Ci from the elbow vein. Patients in whom no abnormality was observed in the cardiopulmonary function were enrolled as subjects. The rCBFI in each intracranial site was calculated from dynamic CT in 10 normal adults (aged 35-60, averaging 46.7) as subjects and compared with the rCBF obtained from SPECT in the same cases and same site. Comparative investigation was made similarly between rCBFI and rCBF regarding 10 patients with tracranial diseases (age 29-65, averaging 51.2). The mean rCBFIs in the normal adults obtained from dynamic CT were 1.15±0.18 U/S in the frontal lobar cortex, 1.28±0.19 U/S in the temporal lobar cortex, 1.43±0.1 U/S in the occipital lobar cortex, 1.27±0.2 U/S in the basal ganglia region and 0.43±0.1 U/S in the white matter. On the other hand, the mean rCBFs by SPECT were 47.36±3.93 ml/100 g/min, 55.19±2.22 ml/100 g/min, 61.92±5.42 ml/100 g/min, 54.38±3.51 ml/100 g/min and 38.68±6.18 ml/100 g/min, respectively. Positive correlation was observed between rCBFIs and rCBFs of 10 normal adults and 10 patients with intracranial disease, totalling 20 cases (r=0.79, P<0.005). The rCBFI by dynamic CT has a correlation with the rCBF by SPECT, suggesting the possibility of its evaluation as an absolute value, though semi-quantitatively. (author)

Non-invasive pulmonary blood flow analysis and blood pressure mapping derived from 4D flow MRI

Science.gov (United States)

Delles, Michael; Rengier, Fabian; Azad, Yoo-Jin; Bodenstedt, Sebastian; von Tengg-Kobligk, Hendrik; Ley, Sebastian; Unterhinninghofen, Roland; Kauczor, Hans-Ulrich; Dillmann, Rüdiger

2015-03-01

In diagnostics and therapy control of cardiovascular diseases, detailed knowledge about the patient-specific behavior of blood flow and pressure can be essential. The only method capable of measuring complete time-resolved three-dimensional vector fields of the blood flow velocities is velocity-encoded magnetic resonance imaging (MRI), often denoted as 4D flow MRI. Furthermore, relative pressure maps can be computed from this data source, as presented by different groups in recent years. Hence, analysis of blood flow and pressure using 4D flow MRI can be a valuable technique in management of cardiovascular diseases. In order to perform these tasks, all necessary steps in the corresponding process chain can be carried out in our in-house developed software framework MEDIFRAME. In this article, we apply MEDIFRAME for a study of hemodynamics in the pulmonary arteries of five healthy volunteers. The study included measuring vector fields of blood flow velocities by phase-contrast MRI and subsequently computing relative blood pressure maps. We visualized blood flow by streamline depictions and computed characteristic values for the left and the right pulmonary artery (LPA and RPA). In all volunteers, we observed a lower amount of blood flow in the LPA compared to the RPA. Furthermore, we visualized blood pressure maps using volume rendering and generated graphs of pressure differences between the LPA, the RPA and the main pulmonary artery. In most volunteers, blood pressure was increased near to the bifurcation and in the proximal LPA, leading to higher average pressure values in the LPA compared to the RPA.

Calf blood flow at rest evaluated by thermal measurement with tissue temperature and heat flow and 133Xe clearance

International Nuclear Information System (INIS)

Tamura, Toshiyo; Togawa, Tatsuo; Fukuoka, Masakazu; Kawakami, Kenji.

1982-01-01

The regional blood flow in the calf was determined simultaneously by thermal measurement and by 133 Xe clearance technique. Calf blood flow (Ft) by thermal measurement was accounted for by the equation of the form Ft=(CdT*d+Ho-Mb)/rho sub(b)c su b(D) (Ta-Td), where Cd is thermal capacitance of the calf compartment, T*d is the change of calf tissue temperature, Ta is arterila blood temperature, Td is calf tissue temperature, Ho is the heat dissipation from the compartment to the environment, Mb is estimated metabolism of the calf tissue and rho sub(b)c sub(b) is the product of density and specific heat of blood. The healthy men were chosen for the experiments. Total calf blood flow was 2.53+-1.31ml/(min-100ml calf), and muscle blood flow was 2.63+-1.69ml/(min- 100ml muscle) and skin blood flow 7.19+-3.83ml/(min-100ml skin) measured by 133 Xe clearance. On the basis of the results, an estimate has been made of the proportions of the calf volume which can be ascribed to skin and muscle respectively. Estimated muscle and skin blood flow were correlated with total calf blood flow(r=0.98). (author)

Regional cerebral blood flow measurement using N-isopropyl-p-(/sup 123/I) iodoamphetamine and rotating gamma camera emission computed tomography

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroshi; Seki, Hiroyasu; Ishida, Hiroko (Kanazawa Univ. (Japan). School of Medicine)

1985-01-01

Thirty-one regional cerebral blood flow (rCBF) measurements were performed on 26 patients with cerebrovascular accidents using N-Isopropyl-p-(/sup 123/I) Iodoamphetamine (/sup 123/I-IMP) and rotating gamma camera emission computed tomography (ECT). The equation for determining rCBF is as follows: F=100.R.Cb/(N.A), where F is rCBF in ml/100 g/min., R is the constant withdrawal rate of arterial blood in ml/min., Cb is the brain activity concentration in ..mu..Ci/g, A is the total activity (5 min.) in the withdrawal arterial whole blood in ..mu..Ci and N is the fraction of A that is true tracer activity (0.75). In determining Cb at 5 min. after injection, reconstructed counts from 35 min. to 59 min. were corrected to represent those from 4 min. to 5 min. with the use of time activity curve for the entire brain immediately after injection to 30 min. Reconstructed counts of central region in tomographic image were corrected 118% of the obtained values from the result of the counting rate ratio between peripheral and central regions of interest obtained from phantom study. Brain mean blood flow values were distributed from 11 to 39 ml/100 g/min. In 119 cortical regions obtained from 11 measurements in 9 patients, there was a significant correlation (r=0.41, p < 0.001) between rCBF values obtained from /sup 123/I-IMP and rotating gamma camera ECT and those from /sup 133/Xe inhalation method. rCBF measurement using /sup 123/I-IMP and rotating gamma camera ECT is not only relatively noninvasive measurement for the entire brain but also three-dimensional evaluation. Besides, it is superior in spatial resolution and accuracy to conventional /sup 133/Xe clearance method.

Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

Energy Technology Data Exchange (ETDEWEB)

Odano, Ikuo [Niigata Univ. (Japan). School of Medicine

1994-04-01

Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) and [sup 99m]Tc-hexamethylpropylene-amine-oxime (HMPAO). The charachteristics, clinical usage and imitation of these two radiolabeled agents are discussed. The advantage of [sup 123]I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of [sup 123]I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of [sup 123]I-IMP. Comparing the rCBF measured by [sup 123]I-IMP with that by [sup 133]Xe inhalation SPECT method, we have to consider PaCO[sub 2] when both SPECT studies are performed, because PaCO[sub 2] is one of the big factors which make effects on the alteration of rCBF. [sup 123]I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume an important datum obtained by the SPECT study with [sup 123]I-IMP, which represent the degree of retention, i.e. binding potential of [sup 123]I-IMP in the brain tissue. I introduced the usage of the distribution volume of [sup 123]I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of [sup 99m] Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence [sup 99m]Tc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author).

Cerebral blood flow in migraine and cortical spreading depression

Energy Technology Data Exchange (ETDEWEB)

Lauritzen, M.

1987-01-01

In a series of migraine patients, carotid arteriography was carried out as part of the clinical evalution. Nine patients developed a migrainous attack with focal neurological symptoms and headache after the angiography and during the subsequent, ongoing regional cerebral blood flow rCBF study. rCBF was measured by bolus injection of Xenon/sup 133/ into the internal carotid artery and a gamma camera with 254 collimated scintillation detectors covering the lateral aspect of the hemisphere. This technique depicts rCBF mainly at the level of the superficial cortex, with no depth resolution. The resolution is 1 cm/sup 2/ providing detailed spatial information of the cortical blood flow. Other methods for measuring local blood flow in animal and man employ a radioactive, freely diffusible tracer, in combination with an autoradiographic technique for the assessment of the tissue concentration, the so-called autoradiographic methods. In the series of patients with spontaneous migraine, rCBF was estimated using an in-vivo application of the autoradiographic principle. Xenon/sup 133/ was administered by inhalation and the time course of the arterial concentration curve was assessed by a scintillation detector over the upper right lung, since the arterial curve has been found to follow the shape of the lung curve. The rCBF was studied accompanying cortical spreading depression in rat experiments to evaluate wheter this phenomenon could explain the blood flow changes in migraine. (/sup 14/C) iodoantipyrine was given as an intravenous bolus injection and the brain content of indicator was determined by tissue sample or autoradiography after 10 or 20 seconds of isotope circulation. The conditions of the autoradiographic methods are that the flow remains constant within the period of measuring, and that the region under study is homogenous with regard to flow and lambda. (EG).

Hemodynamic and regional blood flow distribution responses to dextran, hydralazine, isoproterenol and amrinone during experimental cardiac tamponade

International Nuclear Information System (INIS)

Millard, R.W.; Fowler, N.O.; Gabel, M.

1983-01-01

Four different interventions were examined in dogs with cardiac tamponade. Infusion of 216 to 288 ml saline solution into the pericardium reduced cardiac output from 3.5 +/- 0.3 to 1.7 +/- 0.2 liters/min as systemic vascular resistance increased from 4,110 +/- 281 to 6,370 +/- 424 dynes . s . cm-5. Left ventricular epicardial and endocardial blood flows were 178 +/- 13 and 220 +/- 12 ml/min per 100 g, respectively, and decreased to 72 +/- 14 and 78 +/- 11 ml/min per 100 g with tamponade. Reductions of 25 to 65% occurred in visceral and brain blood flows and in a composite brain sample. Cardiac output during tamponade was significantly increased by isoproterenol, 0.5 microgram/kg per min intravenously; hydralazine, 40 mg intravenously; dextran infusion or combined hydralazine and dextran, but not by amrinone. Total systemic vascular resistance was reduced by all interventions. Left ventricular epicardial flow was increased by isoproterenol, hydralazine and the hydralazine-dextran combination. Endocardial flow was increased by amrinone and the combination of hydralazine and dextran. Right ventricular myocardial blood flow increased with all interventions except dextran. Kidney cortical and composite brain blood flows were increased by both dextran alone and by the hydralazine-dextran combinations. Blood flow to small intestine was increased by all interventions as was that to large intestine by all except amrinone and hydralazine. Liver blood flow response was variable. The most pronounced hemodynamic and tissue perfusion improvements during cardiac tamponade were effected by combined vasodilation-blood volume expansion with a hydralazine-dextran combination. Isoproterenol had as dramatic an effect but it was short-lived. Amrinone was the least effective intervention

Effect of age on cerebral blood flow during hypothermic cardiopulmonary bypass

International Nuclear Information System (INIS)

Brusino, F.G.; Reves, J.G.; Smith, L.R.; Prough, D.S.; Stump, D.A.; McIntyre, R.W.

1989-01-01

Cerebral blood flow was measured in 20 patients by xenon 133 clearance methodology during nonpulsatile hypothermic cardiopulmonary bypass to determine the effect of age on regional cerebral blood flow during these conditions. Measurements of cerebral blood flow at varying perfusion pressures were made in patients arbitrarily divided into two age groups at nearly identical nasopharyngeal temperature, hematocrit value, and carbon dioxide tension and with equal cardiopulmonary bypass flows of 1.6 L/min/m2. The range of mean arterial pressure was 30 to 110 mm Hg for group I (less than or equal to 50 years of age) and 20 to 90 mm Hg for group II (greater than or equal to 65 years of age). There was no significant difference (p = 0.32) between the mean arterial pressure in group I (54 +/- 28 mm Hg) and that in group II (43 +/- 21 mm Hg). The range of cerebral blood flow was 14.8 to 29.2 ml/100 gm/min for group I and 13.8 to 37.5 ml/100 gm/min for group II. There was no significant difference (p = 0.37) between the mean cerebral blood flow in group I (21.5 +/- 4.6 ml/100 gm/min) and group II (24.3 +/- 8.1 ml/100 gm/min). There was a poor correlation between mean arterial pressure and cerebral blood flow in both groups: group I, r = 0.16 (p = 0.67); group II, r = 0.5 (p = 0.12). In 12 patients, a second cerebral blood flow measurements was taken to determine the effect of mean arterial pressure on cerebral blood flow in the individual patient. Changes in mean arterial pressure did not correlate with changes in cerebral blood flow (p less than 0.90). We conclude that age does not alter cerebral blood flow and that cerebral blood flow autoregulation is preserved in elderly patients during nonpulsatile hypothermic cardiopulmonary bypass

Evaluation of arterial digital blood flow using Doppler ultrasonography in healthy dairy cows.

Science.gov (United States)

Müller, H; Heinrich, M; Mielenz, N; Reese, S; Steiner, A; Starke, A

2017-06-06

Local circulatory disturbances have been implicated in the development of foot disorders in cattle. The goals of this study were to evaluate the suitability of the interdigital artery in the pastern region in both hind limbs using pulsed-wave (PW) Doppler ultrasonography and to investigate quantitative arterial blood flow variables at that site in dairy cows. An Esaote MyLabOne ultrasound machine with a 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the pastern region in both hind limbs of 22 healthy German Holstein cows. The cows originated from three commercial farms and were restrained in a standing hoof trimming chute without sedation. A PW Doppler signal suitable for analysis was obtained in 17 of 22 cows. The blood flow profiles were categorised into four curve types, and the following quantitative variables were measured in three uniform cardiac cycles: vessel diameter, pulse rate, maximum systolic velocity, maximum diastolic velocity, end-diastolic velocity, reverse velocity, maximum time-averaged mean velocity, blood flow rate, resistance index and persistence index. The measurements did not differ among cows from the three farms. Maximum systolic velocity, vessel diameter and pulse rate did not differ but other variables differed significantly among blood flow profiles. Differences in weight-bearing are thought to be responsible for the normal variability of blood flow profiles in healthy cows. The scanning technique used in this report for evaluation of blood flow in the interdigital artery appears suitable for further investigations in healthy and in lame cows.

Linear relationship between in distribution of thallium-201 and blood flow in ischemic and nonischemic myocardium during exercise

International Nuclear Information System (INIS)

Nielsen, A.P.; Morris, K.G.; Murdock, R.; Bruno, F.P.; Cobb, F.R.

1980-01-01

The purpose of this study was to compare the myocardial distribution of thallium-201 and regional myocrdial blood flow during ischemia and the physiologic stress of exercise. Studies were carried out in six dogs with chronically implanted catheters in the atrium and aorta and a snare on the circumflex coronary artery distal to the first marginal branch. Regional myocardial blood flow was measured during quiet, resting conditions using 7 to 10 ] of radioisotope-labeled microspheres. Each dog was then exercised on a treadmill at speeds of 5 to 9 mph at a 5/sup o/ incline. (After 1 minute of exercise the cirumflex coronary artery was occluded and thallium-201 and a second label of microspheres were injected. Exercise was continued for 5 minutes. The dogs were then sacrificed and the left ventricle was sectioned into approximately 80 1-2-g samples to compare thallium-201 activity and regional myocardial blood flow. The maximum increase in blood flow ranged from 3.3 to 7.2 times resting control values. Each dog had myocardial samples in which blood flow was markedly reduced, to less than 0.10 ml/min/g. In each dog there was a close linear relationship between thallium-201 distribution and direct measurements of regional myocardial blood flow. Linear regression analyses demonstrated a correlation coefficient of 0.98 or greater in each dog. These data indicate that during the physiologic stress of exercise, the myocardial distribution of thallium activity is linearly related to regional myocardial blood flow in both the ischemic and nonischemic regions

A study on measurement of the regional cerebral blood flow using autoradiographic method in moyamoya disease

International Nuclear Information System (INIS)

Sasaki, Tomohiro; Kiya, Katsuzo; Yuki, Kiyoshi; Kawamoto, Hitoshi; Mizoue, Tatsuya; Kiura, Yoshihiro; Uozumi, Tohru; Ikawa, Fusao

1997-01-01

Development of Autoradiographic method (ARG) has provided measurement of cerebral blood flow in moyamoya disease. We evaluate a cerebral vasodilatory capacity (CVC) for moyamoya disease using ARG method. We used 5 patients with moyamoya disease as a candidate for measurement of the cerebral blood flow (CBF) who admitted to Hiroshima Prefectural Hospital during the past one year. There were 3 patients in an adult age and 2 patients in a young age. We tried to measure the regional CBF (rCBF) using ARG method which was a easy way to estimate the rCBF on SPECT. The CVC was calculated from the difference of the rCBF between resting SPECT and Diamox-loading SPECT. Results were as follows; Reactivity of cerebral vessels to CO 2 loading and CVC weakened in moyamoya disease. The rCBF and CVC in the territories of anterior and middle cerebral arteries reduced in comparison with those in the area supplied by the posterior cerebral artery. The CVC at the treated side with surgical reconstruction recovered somewhat in an adult type. From these results, measurement of CBF using ARG method seems to be useful for evaluation of the CVC in moyamoya disease. (author)

Distribution of the pulmonary blood flow measured by ECT

Energy Technology Data Exchange (ETDEWEB)

Maeda, H.; Itoh, H.; Todo, Y.; Ishii, Y.; Mukai, T. (Kyoto Univ. (Japan). Hospital)

1981-05-01

Distributions of pulmonary blood flow per unit lung volume were observed by using the combination of Tc-99m-MAA and radionuclide CT. Administration of Tc-99m-MAA to the patients were performed in sitting position. Ten patients were studied with this method. In nine patients, the blood flow distribution was greater in the direction of the gravity, namely, more blood flow in the lower than the upper lung region. In six patients were demonstrated the relation between blood flow and the vertical distance described by West et al. Thus, it was possible to evaluate the arterial and venous pressures of the lung with the estimated pressure of 4.15 +- 1.93 cmH/sub 2/O and -5.55 +- 2.48 cmH/sub 2/O in relation to the angle of Louis. The agreement was reasonably well with that reported by Butler and Paley. Three patients had pulmonary hypertension with the distribution of monotonous increase, of which slope was similar to that of zone III in other six patients. The last patient with COPD had quite different distribution from other nine patients.

Regulation of peripheral blood flow in Complex Regional Pain Syndrome: clinical implication for symptomatic relief and pain management

Directory of Open Access Journals (Sweden)

Coderre Terence J

2009-09-01

Full Text Available Abstract Background During the chronic stage of Complex Regional Pain Syndrome (CRPS, impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS. Discussion The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin. Summary The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients.

Partitioning of red blood cell aggregates in bifurcating microscale flows

Science.gov (United States)

Kaliviotis, E.; Sherwood, J. M.; Balabani, S.

2017-03-01

Microvascular flows are often considered to be free of red blood cell aggregates, however, recent studies have demonstrated that aggregates are present throughout the microvasculature, affecting cell distribution and blood perfusion. This work reports on the spatial distribution of red blood cell aggregates in a T-shaped bifurcation on the scale of a large microvessel. Non-aggregating and aggregating human red blood cell suspensions were studied for a range of flow splits in the daughter branches of the bifurcation. Aggregate sizes were determined using image processing. The mean aggregate size was marginally increased in the daughter branches for a range of flow rates, mainly due to the lower shear conditions and the close cell and aggregate proximity therein. A counterintuitive decrease in the mean aggregate size was apparent in the lower flow rate branches. This was attributed to the existence of regions depleted by aggregates of certain sizes in the parent branch, and to the change in the exact flow split location in the T-junction with flow ratio. The findings of the present investigation may have significant implications for microvascular flows and may help explain why the effects of physiological RBC aggregation are not deleterious in terms of in vivo vascular resistance.

Absolute quantification of regional renal blood flow in swine by dynamic contrast-enhanced magnetic resonance imaging using a blood pool contrast agent.

Science.gov (United States)

Lüdemann, Lutz; Nafz, Benno; Elsner, Franz; Grosse-Siestrup, Christian; Meissler, Michael; Kaufels, Nicola; Rehbein, Hagen; Persson, Pontus B; Michaely, Henrik J; Lengsfeld, Philipp; Voth, Matthias; Gutberlet, Matthias

2009-03-01

To evaluate for the first time in an animal model the possibility of absolute regional quantification of renal medullary and cortical perfusion by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a blood pool contrast agent. A total of 18 adult female pigs (age, 16-22 weeks; body weight, 45-65 kg; no dietary restrictions) were investigated by DCE-MRI. Absolute renal blood flow (RBF) measured by an ultrasound transit time flow probe around the renal vein was used as the standard of reference. An inflatable stainless cuff placed around the renal artery near its origin from the abdominal aorta was used to reduce RBF to 60%, 40%, and 20% of the baseline flow. The last measurement was performed with the cuff fully reopened. Absolute RBF values during these 4 perfusion states were compared with the results of DCE-MRI performed on a 1.5-T scanner with an 8-channel phased-array surface coil. All scans were acquired in breath-hold technique in the coronal plane using a field of view of 460 mm.Each dynamic scan commenced with a set of five 3D T1-weighted gradient echo sequences with different flip angles (alpha = 2 degrees, 5 degrees, 10 degrees, 20 degrees, 30 degrees): TE, 0.88 milliseconds; TR, 2.65 milliseconds; slice thickness, 8.8 mm for 4 slices; acquisition matrix, 128 x 128; and acquisitions, 4. These data served to calculate 3D intrinsic longitudinal relaxation rate maps (R10) and magnetization (M0). Immediately after these images, the dynamic 3D T1-weighted gradient echo images were acquired with the same parameters and a constant alpha = 30 degrees, half Fourier, 1 acquisition, 64 frames, a time interval of 1.65 seconds between each frame, and a total duration of 105.6. Three milliliters of an albumin-binding blood pool contrast agent (0.25 mmol/mL gadofosveset trisodium, Vasovist, Bayer Schering Pharma AG, Berlin, Germany) was injected at a rate of 3 mL/s. Perfusion was calculated using the arterial input function from the aorta, which was

Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

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Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan [Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States)

2009-11-15

Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

International Nuclear Information System (INIS)

Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan

2009-01-01

Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 μm 2 ). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0±5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO DSA =CO Fick . Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

Automated segmentation of blood-flow regions in large thoracic arteries using 3D-cine PC-MRI measurements.

Science.gov (United States)

van Pelt, Roy; Nguyen, Huy; ter Haar Romeny, Bart; Vilanova, Anna

2012-03-01

Quantitative analysis of vascular blood flow, acquired by phase-contrast MRI, requires accurate segmentation of the vessel lumen. In clinical practice, 2D-cine velocity-encoded slices are inspected, and the lumen is segmented manually. However, segmentation of time-resolved volumetric blood-flow measurements is a tedious and time-consuming task requiring automation. Automated segmentation of large thoracic arteries, based solely on the 3D-cine phase-contrast MRI (PC-MRI) blood-flow data, was done. An active surface model, which is fast and topologically stable, was used. The active surface model requires an initial surface, approximating the desired segmentation. A method to generate this surface was developed based on a voxel-wise temporal maximum of blood-flow velocities. The active surface model balances forces, based on the surface structure and image features derived from the blood-flow data. The segmentation results were validated using volunteer studies, including time-resolved 3D and 2D blood-flow data. The segmented surface was intersected with a velocity-encoded PC-MRI slice, resulting in a cross-sectional contour of the lumen. These cross-sections were compared to reference contours that were manually delineated on high-resolution 2D-cine slices. The automated approach closely approximates the manual blood-flow segmentations, with error distances on the order of the voxel size. The initial surface provides a close approximation of the desired luminal geometry. This improves the convergence time of the active surface and facilitates parametrization. An active surface approach for vessel lumen segmentation was developed, suitable for quantitative analysis of 3D-cine PC-MRI blood-flow data. As opposed to prior thresholding and level-set approaches, the active surface model is topologically stable. A method to generate an initial approximate surface was developed, and various features that influence the segmentation model were evaluated. The active surface

The effects of hypoxemia on myocardial blood flow during exercise.

Science.gov (United States)

Paridon, S M; Bricker, J T; Dreyer, W J; Reardon, M; Smith, E O; Porter, C B; Michael, L; Fisher, D J

1989-03-01

We evaluated the adequacy of regional and transmural blood flow during exercise and rapid pacing after 1 wk of hypoxemia. Seven mature mongrel dogs were made hypoxemic (mean O2 saturation = 72.4%) by anastomosis of left pulmonary artery to left atrial appendage. Catheters were placed in the left atrium, right atrium, pulmonary artery, and aorta. Atrial and ventricular pacing wires were placed. An aortic flow probe was placed to measure cardiac output. Ten nonshunted dogs, similarly instrumented, served as controls. Recovery time was approximately 1 wk. Cardiac output, mean aortic pressure, and oxygen saturation were measured at rest, with ventricular pacing, atrial pacing, and with treadmill exercise. Ventricular and atrial pace and exercise were at a heart rate of 200. Right ventricular free wall, left ventricular free wall, and septal blood flow were measured with radionuclide-labeled microspheres. Cardiac output, left atrial blood pressure, and aortic blood pressure were similar between the two groups of dogs in all testing states. Myocardial blood flow was significantly higher in the right and left ventricular free wall in the hypoxemic animals during resting and exercise testing states. Myocardial oxygen delivery was similar between the two groups of animals. Pacing resulted in an increase in myocardial blood flow in the control animals but not the hypoxemic animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of organ blood flow using tritiated water. II. Uterine blood flow in conscious pregnant ewes

International Nuclear Information System (INIS)

Brown, B.W.; Oddy, V.H.; Jones, A.W.

1982-01-01

Total uterine blood flow was measured with a tritiated water (TOH) diffusion method and with radioactive microspheres in six, conscious, pregnant ewes. With continuous infusion of TOH, equilibrium between the TOH concentration in utero-ovarian venous blood and arterial blood was attained within 50 min of the start of the infusion. The concentration of TOH in uterine and foetal tissue and in foetal blood water was the same as that in uterine venous water by 40 min; at this time, the concentration of TOH in the water of amniotic and allantoic fluids was 96% of that in uterine venous blood water. Estimates of total uterine blood flow obtained using TOH were highly correlated with those obtained with microspheres and the corresponding mean flow values obtained with the two techniques did not significantly differ. The percentage of the total uterine blood flow passing through arteriovenous anastomoses ranged from 1.4 to 3.3%

Continuous determination of regional myocardial blood flow with intracoronary krypton-81m in coronary artery disease

International Nuclear Information System (INIS)

Remme, W.J.; Krauss, X.H.; van Hoogenhuyze, D.C.; Cox, P.H.; Storm, C.J.; Kruyssen, D.A.

1985-01-01

Pacing-induced changes in regional coronary flow were studied continuously with krypton-81m by intracoronary infusion in 25 patients: 21 with 50% or greater diameter narrowing of 1 or more left coronary arteries (group I) and 4 with less than 50% diameter reduction of a left coronary artery (group II). No changes occurred in group II. In group I, krypton-81m perfusion decreased progressively in all areas with more than 70% diameter narrowing, with a simultaneous increase in normal regions. At the end of pacing during angina, krypton-81m perfusion was reduced to 81 +/- 4% of control in areas with 71 to 90% diameter reduction (n = 8) and to 69 +/- 6% in areas with more than 90% diameter narrowing (n = 15). In contrast, in regions with 50 to 70% diameter reduction changes were variable (decrease in 4 regions, increase in 2 and an unchanged distribution in 1 region). Krypton-81m perfusion decreased early, before general signs of ischemia in areas with more than 90% diameter reduction, whereas this decrease occurred later in regions with 71 to 90% diameter narrowing, concurrently with ST-segment changes but before anginal pain. Although all signs of ischemia had disappeared between 2 and 5 minutes after pacing, changes in krypton-81m distribution persisted in most areas for 5 to 15 minutes after pacing. It is concluded that the functional significance of coronary arterial narrowing can be assessed with a continuous intracoronary infusion of krypton-81m. Changes in regional distribution persisted after cessation of pacing-induced ischemia, indicating an ongoing decrease in regional myocardial blood flow

Regional cerebral blood flow during mechanical hyperventilation in patients with fulminant hepatic failure

DEFF Research Database (Denmark)

Strauss, Gitte Irene; Høgh, Peter; Møller, Kirsten

1999-01-01

Hyperventilation is frequently used to prevent or postpone the development of cerebral edema and intracranial hypertension in patients with fulminant hepatic failure (FHF). The influence of such therapy on regional cerebral blood flow (rCBF) remains, however, unknown. In this study the CBF......-distribution pattern was determined within the first 12 hours after development of hepatic encephalopathy (HE) stage 4 before and during hyperventilation. Ten consecutive patients (median age 48 [range 33-57] years) with FHF and 9 healthy controls (median age 54 [24-58] years) had rCBF determined by single photon...... emission computed tomography (SPECT) using intravenous injection of 133Xenon. For determination of high resolution CBF pattern, the patients were also studied with 99mTc-hexa-methylpropyleneamine oxime (HMPAO) in the hyperventilation condition. There was no significant difference in the rCBF distribution...

Effects of hypothyroidism on the skeletal muscle blood flow response to contractions.

Science.gov (United States)

Bausch, L; McAllister, R M

2003-04-01

Hypothyroidism is associated with impaired blood flow to skeletal muscle under whole body exercise conditions. It is unclear whether poor cardiac and/or vascular function account for blunted muscle blood flow. Our experiment isolated a small group of hindlimb muscles and simulated exercise via tetanic contractions. We hypothesized that muscle blood flow would be attenuated in hypothyroid rats (HYPO) compared with euthyroid rats (EUT). Rats were made hypothyroid by mixing propylthiouracil in their drinking water (2.35 x 10-3 mol/l). Treatment efficacy was evidenced by lower serum T3 concentrations and resting heart rates in HYPO (both Pmuscles at a rate of 30 tetani/min were induced via sciatic nerve stimulation. Regional blood flows were determined by the radiolabelled microsphere method at three time points: rest, 2 min of contractions and 10 min of contractions. Muscle blood flow generally increased from rest ( approximately 5-10 ml/min per 100 g) through contractions for both groups. Further, blood flow during contractions did not differ between groups for any muscle (eg. red section of gastrocnemius muscle; EUT, 59.9 +/- 14.1; HYPO, 61.1 +/- 15.0; NS between groups). These findings indicate that hypothyroidism does not significantly impair skeletal muscle blood flow when only a small muscle mass is contracting. Our findings suggest that impaired blood flow under whole body exercise is accounted for by inadequate cardiac function rather than abnormal vascular function.

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

Principles of the tracer method in assessing regional blood flow

International Nuclear Information System (INIS)

Potchen, E.J.; Siegel, B.; Meidinger, R.

1972-01-01

The standard brain scan is abnormal when there is relative increase in blood volume or when there is an abnormal permeability to substances which normally cannot enter the brain tissue. The usual mechanism of abnormal permeability is based upon neovascularity in tissues which do not maintain the tight junctions one sees in the normal brain endothelium. These tight junctions prohibit the leakage of materials from the intra- to extravascular space, and when they are not available many materials can readily transit into the abnormal tissue substance and can therefore be discerned on a standard brain scan. In many instances, however, there is no gross breakdown in this blood-brain barrier, but more subtle derangement may be detected by determining changes in regional brain blood volume or the relative volume of distribution of various labeled materials. We have studied whether or not we can discern differences in brain spaces of two isotopes in experimental situations where the brain scan would be normal. For these models, we have used water-induced brain edema and triethyl-tin-induced brain edema in the experimental animal. In water intoxication, there is no difference in the microvascular anatomy or change in the 99 /sup m/Tc pertechnetate space, but it is apparent from our studies that the brain swells at the expense of brain blood volume and by measuring brain blood volume against brain mass, i.e., transit of 131 I antipyrine versus 51 Cr labeled red cells, one can detect brain edema in a situation where the brain scan would be normal. It is these approaches with cameras and computers using dual energies that may afford a more simplified estimation of altered regional brain function than is now available with the internal carotid injection technique. (U.S.)

Pulsatile spiral blood flow through arterial stenosis.

Science.gov (United States)

Linge, Fabian; Hye, Md Abdul; Paul, Manosh C

2014-11-01

Pulsatile spiral blood flow in a modelled three-dimensional arterial stenosis, with a 75% cross-sectional area reduction, is investigated by using numerical fluid dynamics. Two-equation k-ω model is used for the simulation of the transitional flow with Reynolds numbers 500 and 1000. It is found that the spiral component increases the static pressure in the vessel during the deceleration phase of the flow pulse. In addition, the spiral component reduces the turbulence intensity and wall shear stress found in the post-stenosis region of the vessel in the early stages of the flow pulse. Hence, the findings agree with the results of Stonebridge et al. (2004). In addition, the results of the effects of a spiral component on time-varying flow are presented and discussed along with the relevant pathological issues.

Regional cerebral blood flow in various pediatric neurological patients using /sup 123/I-IMP SPECT

Energy Technology Data Exchange (ETDEWEB)

Konishi, Tohru; Naganuma, Yoshihiro; Hongou, Kazuhisa; Murakami, Miyako; Yamatani, Miwa; Okada, Toshio

1988-03-01

The recent development of a new radiopharmaceutical /sup 123/I-isopropyl-iodoamphetamine (IMP), which is taken up by the brain from the blood flow, has offered a possibility of constructing scintigraphy maps of regional cerebral blood flow (rCBF) using single photon emission CT. We used this mehtod in various pediatric neurological diseases. Six patients with cerebro-vascular disorders (moya-moya disease 2, infarction 3 and HHE syndrome 1), 6 patients with infectious diseases of CNS (acute encephalitis 4, septic meningitis 1 and SSPE 1) and a miscellaneous group of six patients were studied. The rCBF abnormalities in cerebro-vascular diseases were more extensive and frequent than x-ray CT abnormalities. Repeated studies of IMP-SPECT revealed usefulness for the understanding of changeable hemodynamic pathophysiology and for the judgment of theraptic effectiveness and prognosis. The rCBF decrease in infectious diseases tended to be more diffuse and slight than that in cerebro-vascular diseases. In almost all patients, the area of rCBF decrease coincided with the area of EEG slowing evaluated by EEG topographic analysis. Brain imaging using /sup 123/I-IMP SPECT may reveal functional abnormalities as well as organic lesions. /sup 123/I-IMP SPECT has introduced a new era for the useful application of nuclear medicine to the investigation of pediatric neurological diseases.

An analysis of regional cerebral blood flow in impulsive murderers using single photon emission computed tomography.

Science.gov (United States)

Amen, Daniel G; Hanks, Chris; Prunella, Jill R; Green, Aisa

2007-01-01

The authors explored differences in regional cerebral blood flow in 11 impulsive murderers and 11 healthy comparison subjects using single photon emission computed tomography. The authors assessed subjects at rest and during a computerized go/no-go concentration task. Using statistical parametric mapping software, the authors performed voxel-by-voxel t tests to assess significant differences, making family-wide error corrections for multiple comparisons. Murderers were found to have significantly lower relative rCBF during concentration, particularly in areas associated with concentration and impulse control. These results indicate that nonemotionally laden stimuli may result in frontotemporal dysregulation in people predisposed to impulsive violence.

Characteristic regional cerebral blood flow patterns in anorexia nervosa patients with binge/purge behavior.

Science.gov (United States)

Naruo, T; Nakabeppu, Y; Sagiyama, K; Munemoto, T; Homan, N; Deguchi, D; Nakajo, M; Nozoe, S

2000-09-01

The authors' goal was to investigate the effect of imagining food on the regional cerebral blood flow (rCBF) of anorexia nervosa patients with and without habitual binge/purge behavior. The subjects included seven female patients with purely restrictive anorexia, seven female patients with anorexia and habitual binge/purge behavior, and seven healthy women. Single photon emission computed tomography examination was performed before and after the subjects were asked to imagine food. Changes in rCBF count ratios (percent change) were then calculated and compared. The subjects were also asked to assess their degree of fear regarding their control of food intake. The anorexia nervosa patients with habitual binge/purge behavior had a significantly higher percent change in the inferior, superior, prefrontal, and parietal regions of the right brain than the patients with purely restrictive anorexia and the healthy volunteers. The patients with habitual binge/purge behavior also had the highest level of apprehension in regard to food intake. Specific activation in cortical regions suggests an association between habitual binge/purge behavior and the food recognition process linked to anxiety in patients with anorexia nervosa.

Radioisotopic flow scanning for portal blood flow and portal hypertension

International Nuclear Information System (INIS)

Hesdorffer, C.S.; Bezwoda, W.R.; Danilewitz, M.D.; Esser, J.D.; Tobias, M.

1987-01-01

The use of a simple, noninvasive, isotope scanning technique for the determination of relative portal blood flow and detection of portal hypertension is described. Using this technique the presence of portal hypertension was demonstrated in seven of nine patients known to have elevated portal venous pressure. By contrast, esophageal varices were demonstrated in only five of these patients, illustrating the potential value of the method. Furthermore, this technique has been adapted to the study of portal blood flow in patients with myeloproliferative disorders with splenomegaly but without disturbances in hepatic architecture. Results demonstrate that the high relative splenic flow resulting from the presence of splenomegaly may in turn be associated with elevated relative portal blood flow and portal hypertension. The theoretic reasons for the development of flow-related portal hypertension and its relationship to splenic blood flow are discussed

SPECT determination of regional cerebral blood flow in hypertensive patients before and after clonidine

International Nuclear Information System (INIS)

Devous, M.D.; Reed, W.G.; Chehabi, H.H.; Bonte, F.J.

1985-01-01

Regional cerebral blood flow (rCBF) was determined by SPECT of 133-Xe inert gas washout in 18 hypertensive patients (PTS) upon admission and after treatment with oral clonidine (CL, 0.2 mg, then 0.1 mg/hr until diastolic pressure reached 105 mm Hg or fell by 30 mm Hg). CL reduced mean arterial pressure (MAP) from 160 (200/140) to 133 (150/100) mm Hg over 4-6 hr. RCBF was quantitated in 14 gray matter regions from cross-sectional images and analyzed for differences from normal controls and changes with CL. Initial rCBF was lower in HI PTS than in either normal controls of LO PTS in all brain regions. CL lowered MAP in HI PTS by 52 +- 15 mm Hg and caused reduction in all gray matter regions except right frontal and right temporal (mean reduction 5 +- 2 ml/min/100 g, rho<.05). RCBF images were also evaluated by two trained observers for initial regional defects and for changes with CL. LO PTS were more likely to have defects in rCBF images at rest which would resolve with CL. HI PTS frequently had normal images at rest and developed defects with CL. In summary, the study suggests that SPECT may be useful in detecting rCBF abnormalities in hypertensive PTS at rest and following reductions in MAP

In-vitro study on haemodiluted blood flow in a sinusoidal microstenosis.

Science.gov (United States)

Kang, M J; Ji, H-S; Lee, S J

2010-01-01

In-vitro experiments were carried out to investigate the haemodynamic and haemorheological behaviours of haemodiluted blood flow through a microstenosis using a micro-particle image velocimetry (PIV) technique. The micro-PIV system employed in this study consisted of a two-head neodymium:yttrium-aluminium-garnet (Nd:YAG) laser, a cooled charge-coupled device camera, and a delay generator. To simulate blood flow in a stenosed vascular vessel, a polydimethylsiloxane (PDMS) microchannel with a sinusoidal throat of 80 per cent severity was employed. The width and depth of the microchannel were 100 microm and 50 microm, respectively. To compare the flow characteristics in the microstenosis, the same experiments were repeated in a straight microchannel under the same flow conditions. Using a syringe pump, human blood with 5 per cent haematocrit was supplied into the microstenosis channel. The flow characteristics and transport of blood cells through the microstenosis were investigated with various flowrates. The mean velocity fields were nearly symmetric with respect to the channel centreline. In the contraction section, the oncoming blood flow was accelerated rapidly, and the maximum velocity at the throat was almost 4.99 times faster than that of the straight microchannel without stenosis. In the diffusion section, the blood cells show rolling, deformation, twisting, and tumbling motion due to the flow-choking characteristics at the stenotic region. The results from this study will provide useful basic data for comparison with those obtained by clinical researchers.

Local cerebral blood flow and glucose metabolism during seizure in spontaneously epileptic El mice

International Nuclear Information System (INIS)

Hosokawa, Chisa; Ochi, Hironobu; Yamagami, Sakae; Kawabe, Joji; Kobashi, Toshiko; Okamura, Terue; Yamada, Ryusaku

1995-01-01

Local cerebral blood flow and glucose metabolism were examined in spontaneously epileptic El mice using autoradiography with 125 I-IMP and 14 C-DG in the interictal phase and during seizure. El (+) mice that developed generalized tonic-clonic convulsions and El (-) mice that received no stimulation and had no history of epileptic seizures were examined. The seizure non-susceptible, maternal strain ddY mice were used as control. Uptake ratios for IMP and DG in mouse brain were calculated using the autoradiographic density. In the interictal phase, the pattern of local cerebral blood flow of El (+) mice was similar to that of ddY and El (-) mice, and glucose metabolism in the hippocampus was higher in El (+) mice than in El (-) and ddY mice, but flow and metabolism were nearly matched. During seizure, no significant changed blood flow and increased glucose metabolism in the hippocampus, the epileptic focus, and no markedly changed blood flow and depressed glucose metabolism in other brain regions were observed and considered to be flow-metabolism uncoupling. These observations have never been reported in clinical or experimental studies of epilepsy. Seizures did not cause large regional differences in cerebral blood flow. Therefore, only glucose metabolism is useful for detection of the focus of secondary generalized seizures in El mice, and appeared possibly to be related to the pathophysiology of secondary generalized epilepsy in El mice. (author)

Altered Cerebral Blood Flow Covariance Network in Schizophrenia.

Science.gov (United States)

Liu, Feng; Zhuo, Chuanjun; Yu, Chunshui

2016-01-01

Many studies have shown abnormal cerebral blood flow (CBF) in schizophrenia; however, it remains unclear how topological properties of CBF network are altered in this disorder. Here, arterial spin labeling (ASL) MRI was employed to measure resting-state CBF in 96 schizophrenia patients and 91 healthy controls. CBF covariance network of each group was constructed by calculating across-subject CBF covariance between 90 brain regions. Graph theory was used to compare intergroup differences in global and nodal topological measures of the network. Both schizophrenia patients and healthy controls had small-world topology in CBF covariance networks, implying an optimal balance between functional segregation and integration. Compared with healthy controls, schizophrenia patients showed reduced small-worldness, normalized clustering coefficient and local efficiency of the network, suggesting a shift toward randomized network topology in schizophrenia. Furthermore, schizophrenia patients exhibited altered nodal centrality in the perceptual-, affective-, language-, and spatial-related regions, indicating functional disturbance of these systems in schizophrenia. This study demonstrated for the first time that schizophrenia patients have disrupted topological properties in CBF covariance network, which provides a new perspective (efficiency of blood flow distribution between brain regions) for understanding neural mechanisms of schizophrenia.

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

Artificial blood-flow controlling effects of inhomogeneity of twisted magnetic fields

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Nakagawa, Hidenori; Ohuchi, Mikio

2017-06-01

We developed a blood-flow controlling system using magnetic therapy for some types of nervous diseases. In our research, we utilized overlapped extremely low frequency (ELF) fields for the most effective blood-flow for the system. Results showed the possibility that the inhomogeneous region obtained by overlapping the fields at 50 Hz, namely, a desirably twisted field revealed a significant difference in induced electromotive forces at the insertion points of electrodes. In addition, ELF exposures with a high inhomogeneity of the twisted field at 50 Hz out of phase were more effective in generating an induced electromotive difference by approximately 31%, as contrasted with the difference generated by the exposure in phase. We expect that the increase of the inhomogeneity of the twisted field around a blood vessel can produce the most effective electromotive difference in the blood, and also moderately affect the excitable cells relating to the autonomic nervous system for an outstanding blood-flow control in vivo.

Effects of captopril on cerebral blood flow in normotensive and hypertensive rats

International Nuclear Information System (INIS)

Barry, D.I.; Paulson, O.B.; Jarden, J.O.; Juhler, M.; Graham, D.I.; Strandgaard, S.

1984-01-01

Cerebrovascular effects of the angiotensin converting enzyme inhibitor captopril were examined in normotensive and hypertensive rats. Cerebral blood flow was measured with the intracarotid 133 xenon injection method in halothane-anesthetized animals. The blood-brain barrier permeability of captopril (determined with an integral-uptake method) was negligible, the permeability-surface area product in most brain regions being 1 X 10(-5) cm3/g per second, that is, three to four times lower than that of sodium ion. When administered into the cerebral ventricles to bypass the blood-brain barrier, captopril had no effect on cerebral blood flow: furthermore, cerebral blood flow autoregulation (studied by raising and lowering blood pressure) was identical to that in controls. In contrast, when given intravenously, captopril had a marked effect on cerebral blood flow autoregulation--both the lower and upper limits of autoregulation being shifted to a lower pressure (by about 20 to 30 and 50 to 60 mm Hg, respectively), and the autoregulatory range was shortened by about 40 mm Hg. This effect may be ascribed to inhibition of converting enzyme in the cerebral blood vessels rather than within the brain

Nutrient and nonnutrient renal blood flow

International Nuclear Information System (INIS)

Young, J.S.; Passmore, J.C.; Hartupee, D.A.; Baker, C.H.

1990-01-01

The role of prostaglandins in the distribution of total renal blood flow (TRBF) between nutrient and nonnutrient compartments was investigated in anesthetized mongrel dogs. Renal blood flow distribution was assessed by the xenon 133 freeze-dissection technique and by rubidium 86 extraction after ibuprofen treatment. Ibuprofen (13 mg/kg) significantly decreased TRBF by 16.3% +/- 1.2% (mean +/- SEM electromagnetic flow probe; p less than 0.005), but did not alter blood flows to the outer cortex (3.7 vs 4.3 ml/min per gram), the inner cortex (2.6 vs 2.7 ml/min per gram), and the other medulla (1.5 vs 1.5 ml/min per gram), which suggests a decrease in nonnutrient flow. In a separate group of animals the effect of reduced blood flow on the nutrient and nonnutrient components was determined by mechanically reducing renal arterial blood flow by 48%. Unlike the ibuprofen group, nutrient blood flows were proportionally reduced with the mechanical decrease in TRBF in the outer cortex (1.9 ml/min per gram, p less than 0.05), the inner cortex (1.4 ml/min per gram, p less than 0.05), and the outer medulla (0.8 ml/min per gram, p less than 0.01). These results indicate no shift between nutrient and nonnutrient compartments. Nutrient and nonnutrient renal blood flows of the left kidney were also determined by 86Rb extraction. After ibuprofen treatment, nonextracted 86Rb decreased to 12.1% from the control value of 15.6% (p less than 0.05). Mechanical reduction of TRBF did not significantly decrease the proportion of unextracted 86Rb (18.7%)

Microsphere estimates of blood flow: Methodological considerations

International Nuclear Information System (INIS)

von Ritter, C.; Hinder, R.A.; Womack, W.; Bauerfeind, P.; Fimmel, C.J.; Kvietys, P.R.; Granger, D.N.; Blum, A.L.

1988-01-01

The microsphere technique is a standard method for measuring blood flow in experimental animals. Sporadic reports have appeared outlining the limitations of this method. In this study the authors have systematically assessed the effect of blood withdrawals for reference sampling, microsphere numbers, and anesthesia on blood flow estimates using radioactive microspheres in dogs. Experiments were performed on 18 conscious and 12 anesthetized dogs. Four blood flow estimates were performed over 120 min using 1 x 10 6 microspheres each time. The effects of excessive numbers of microspheres pentobarbital sodium anesthesia, and replacement of volume loss for reference samples with dextran 70 were assessed. In both conscious and anesthetized dogs a progressive decrease in gastric mucosal blood flow and cardiac output was observed over 120 min. This was also observed in the pancreas in conscious dogs. The major factor responsible for these changes was the volume loss due to the reference sample withdrawals. Replacement of the withdrawn blood with dextran 70 led to stable blood flows to all organs. The injection of excessive numbers of microspheres did not modify hemodynamics to a greater extent than did the injection of 4 million microspheres. Anesthesia exerted no influence on blood flow other than raising coronary flow. The authors conclude that although blood flow to the gastric mucosa and the pancreas is sensitive to the minor hemodynamic changes associated with the microsphere technique, replacement of volume loss for reference samples ensures stable blood flow to all organs over a 120-min period

Subcutaneous blood flow in early male pattern baldness

International Nuclear Information System (INIS)

Klemp, P.; Peters, K.; Hansted, B.

1989-01-01

The subcutaneous blood flow (SBF) was measured by the 133 Xe washout method in the scalp of 14 patients with early male pattern baldness. Control experiments were performed in 14 normal haired men matched for age. The SBF in the scalp of the normal individuals was about 10 times higher than previously reported SBF values in other anatomical regions. In patients with early male pattern baldness, SBF was 2.6 times lower than the values found in the normal individuals (13.7 +/- 9.6 vs 35.7 +/- 10.5 ml/100 g/min-1). This difference was statistically significant (p much less than 0.001). A reduced nutritive blood flow to the hair follicles might be a significant event in the pathogenesis of early male pattern baldness

Sex differences of human cortical blood flow and energy metabolism.

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Aanerud, Joel; Borghammer, Per; Rodell, Anders; Jónsdottir, Kristjana Y; Gjedde, Albert

2017-07-01

Brain energy metabolism is held to reflect energy demanding processes in neuropil related to the density and activity of synapses. There is recent evidence that men have higher density of synapses in temporal cortex than women. One consequence of these differences would be different rates of cortical energy turnover and blood flow in men and women. To test the hypotheses that rates of oxygen consumption (CMRO 2 ) and cerebral blood flow are higher in men than in women in regions of cerebral cortex, and that the differences persist with aging, we used positron emission tomography to determine cerebral blood flow and cerebral metabolic rate of oxygen as functions of age in healthy volunteers of both sexes. Cerebral metabolic rate of oxygen did not change with age for either sex and there were no differences of mean values of cerebral metabolic rate of oxygen between men and women in cerebral cortex. Women had significant decreases of cerebral blood flow as function of age in frontal and parietal lobes. Young women had significantly higher cerebral blood flow than men in frontal and temporal lobes, but these differences had disappeared at age 65. The absent sex difference of cerebral energy turnover suggests that the known differences of synaptic density between the sexes are counteracted by opposite differences of individual synaptic activity.

Facial skin blood flow responses during exposures to emotionally charged movies.

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Matsukawa, Kanji; Endo, Kana; Ishii, Kei; Ito, Momoka; Liang, Nan

2018-03-01

The changes in regional facial skin blood flow and vascular conductance have been assessed for the first time with noninvasive two-dimensional laser speckle flowmetry during audiovisually elicited emotional challenges for 2 min (comedy, landscape, and horror movie) in 12 subjects. Limb skin blood flow and vascular conductance and systemic cardiovascular variables were simultaneously measured. The extents of pleasantness and consciousness for each emotional stimulus were estimated by the subjective rating from -5 (the most unpleasant; the most unconscious) to +5 (the most pleasant; the most conscious). Facial skin blood flow and vascular conductance, especially in the lips, decreased during viewing of comedy and horror movies, whereas they did not change during viewing of a landscape movie. The decreases in facial skin blood flow and vascular conductance were the greatest with the comedy movie. The changes in lip, cheek, and chin skin blood flow negatively correlated (P < 0.05) with the subjective ratings of pleasantness and consciousness. The changes in lip skin vascular conductance negatively correlated (P < 0.05) with the subjective rating of pleasantness, while the changes in infraorbital, subnasal, and chin skin vascular conductance negatively correlated (P < 0.05) with the subjective rating of consciousness. However, none of the changes in limb skin blood flow and vascular conductance and systemic hemodynamics correlated with the subjective ratings. The mental arithmetic task did not alter facial and limb skin blood flows, although the task influenced systemic cardiovascular variables. These findings suggest that the more emotional status becomes pleasant or conscious, the more neurally mediated vasoconstriction may occur in facial skin blood vessels.

Advances in regional cerebral blood flow measurement and patho-physiological analysis by SPECT

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Odano, Ikuo (Niigata Univ. (Japan). School of Medicine)

1994-04-01

Recently, two kinds of radiopharmaceuticals have been developed to represent the biodistribution of regional blood flow, which are N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) and [sup 99m]Tc-hexamethylpropylene-amine-oxime (HMPAO). The charachteristics, clinical usage and imitation of these two radiolabeled agents are discussed. The advantage of [sup 123]I-IMP is that it has high first-pass extraction and long retention in brain tissue, hence it can be used to measure the absolute values of regional cerebral blood flow (rCBF). When the kinetics of [sup 123]I-IMP is assumed to be freely diffusible in the brain, its behavior is considered by 2-compartment model, especially which is assumed by the microsphere model in the early period after the i.v. injection of [sup 123]I-IMP. Comparing the rCBF measured by [sup 123]I-IMP with that by [sup 133]Xe inhalation SPECT method, we have to consider PaCO[sub 2] when both SPECT studies are performed, because PaCO[sub 2] is one of the big factors which make effects on the alteration of rCBF. [sup 123]I-IMP has an interesting character of the redistribution phenomenon which represrent the degree of ischemia in the cerebrovascular diseases. Distribution volume an important datum obtained by the SPECT study with [sup 123]I-IMP, which represent the degree of retention, i.e. binding potential of [sup 123]I-IMP in the brain tissue. I introduced the usage of the distribution volume of [sup 123]I-IMP, which was constructed in the rate constant square method, in the differential diagnosis of Parkinson's disease and progressive supranuclear palsy (PSP). The clinical usage of [sup 99m] Tc-HMPAT was mentioned, the advantage of which is the rapid fixation in the brain tissue and the distribution does not change for long time after the i.v. injection. Hence [sup 99m]Tc-HMPAO is used for the diagnosis of epileptic foci and certain loading tests such as balloon occlusion test, postural test and acetazolamide loading test. (author).

Blood flow distribution in dog gastrocnemius muscle at rest and during stimulation

International Nuclear Information System (INIS)

Piiper, J.; Pendergast, D.R.; Marconi, C.; Meyer, M.; Heisler, N.; Cerretelli, P.

1985-01-01

The distribution of blood flow within the isolated perfused dog gastrocnemius muscle (weight 100-240 g) was studied by intra-arterial injection of radioactively labeled microspheres (diameter 15 micron) at rest and during supramaximal stimulation to rhythmic isotonic tetanic contractions of varied frequency against varied loads. After the experiment the muscle was cut into 180-250 pieces of approximately 0.75 g each, and the blood flow to each muscle piece was determined from its radioactivity. The inhomogeneity of blood flow was represented as the frequency distribution of the ratios of regional specific blood flow, i.e., blood flow per unit tissue weight of the piece, QR, to the overall specific blood flow of the muscle, Q. The QR/Q values for the individual pieces of a muscle were found to vary widely both at rest and during stimulation. With rising work load the frequency distribution had a tendency to broaden and flatten, indicating increasing perfusion inhomogeneity. On the average of the experiments, there was no significant difference in specific blood flow between the three anatomic components of the gastrocnemius (lateral and medial heads of gastrocnemius and flexor digitorum superficialis) nor between the superficial and deep portions within these anatomic components, only the distal third of the muscle was relatively less perfused compared with the proximal two-thirds. The considerable inhomogeneity of blood flow as revealed by microsphere embolization and by other methods is expected to exert important limiting effects on local O 2 supply, particularly during exercise

Relationships among arteriolar, regional, and whole organ blood flow in cremaster muscle

International Nuclear Information System (INIS)

Proctor, K.G.; Busija, D.W.

1985-01-01

The relationship between microvessel and tissue blood flow (BF) was determined with two different techniques during changes in local vasomotor tone in the rat cremaster muscle. Whole organ and regional BF were measured with the radioactive microsphere technique (BFms) and compared with values calculated in individual arterioles (BFc) using the dual-slit cross-correlation technique. In the muscle prepared for microcirculatory observation (i.e., dissected, surgically divided into a flattened sheet, and covered with clear plastic), resting BFms was 43 +/- 3 ml X min-1 X 100 g-1, which was significantly higher than paired BFms in the contralateral undisturbed muscle (24 +/- 7 ml X min-1 X 100 g-1). Over a range in vasomotor tone, regional BFms to the edge of the tissue, which was exposed to the trauma of the surgery, was 56 +/- 7 ml X min-1 X 100 g-1 compared with 38 +/- 5 in the less traumatized center region, a significant difference of 79 +/- 31%. There was no linear relationship between arteriolar BFc and BFms. The correlation was not improved if the factors of vessel size, vasomotor tone, animal size, or muscle size were considered. Changes in arteriolar BFc (y) overestimated changes in total tissue BFms (x) by a factor of 2 (y = 2.01x - 0.6; r = 0.86), but changes in arteriolar BFc were proportional to changes in BFms if only the center region (x) of the tissue was considered (y = 1.08x - 0.1; r = 0.84). The general implication from these results is that factors that influence perfusion heterogeneity, such as surgical trauma, should be carefully considered when correlating macro- and microcirculatory measurements of BF

Modified Beer-Lambert law for blood flow.

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Baker, Wesley B; Parthasarathy, Ashwin B; Busch, David R; Mesquita, Rickson C; Greenberg, Joel H; Yodh, A G

2014-11-01

We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.

The clinical study of cerebral blood flow imaging in patients with early syphilis

International Nuclear Information System (INIS)

Liu Zengli; Shi Xin; Wu Jinchang; Tang Jun; Zhong Jijun

2003-01-01

Objective: To study the clinical value of cerebral blood flow imaging for evaluation of patients with early syphilis. Methods: Fifty-three patients with early syphilis underwent cerebral blood flow imaging using 99 Tc m -ethylenecysteinate dimer(ECD). Regional cerebral blood flow (rCBF) changes were analyzed. Results: The acquired images of 53 patients were graded as 5 types. The rCBF was significantly depressed in 48 of 53 patients mainly in the areas dominated by anterior cerebral artery and middle cerebral artery. Conclusion: Treponema pallidum (TP) could start invading central nervous system at the early stage of infection

Regional cerebral blood flow in aged diabetic patients without a history of cerebrovascular accident, determined by N-isopropyl-123I-p-iodoamphetamine with single photon emission CT

International Nuclear Information System (INIS)

Wakisaka, Masanori; Nagamachi, Shigeki; Inoue, Kenjiro; Morotomi, Yasuyuki; Nunoi, Kiyohide; Fujishima, Masatoshi.

1989-01-01

N-isopropyl- 123 I-p-iodoamphetamine (IMP) was used to determine the regional cerebral blood flow in 9 diabetic patients (average age: 71.8 years) and 9 non-diabetic subjects (average age: 71.7 years), none of whom had a history of cerebrovascular accident. There were no significant differences in the physiological or laboratory data between the diabetic and non-diabetic groups except in fasting plasma glucose and HbA 1 c levels. Areas of hypoperfusion of the cerebral hemispheres were observed in 7 diabetic patients, 5 of whom showed multiple lesions. On the other hand, areas of hypoperfusion were observed only in 4 of the non-diabetic subjects and only 1 of these demonstrated multiple lesions. We evaluated the cerebral blood flow semiquantitatively as follows: the area where the radioactive count was 65% or more of the maximum count of the slice was defined as a region of normal cerebral blood flow (ROI-A); the area where the count was 45% or more as region of brain tissue except for ventricles (RUI-B). The numbers of pixels of ROI-A and ROI-B were counted in each slice and the ROI-A/B ratios of 16 slices were averaged individually. The average percent ROI-A/B ratio was significantly lower in the diabetic group than that in the control group (49.4±1.9 (Mean±SEM) vs 56.6±1.9%, p<0.05). These observations suggest that the area of normal regional cerebral blood flow is reduced in aged diabetics, even in the absence of a history of cerebrovascular accident. (author)

Effect of furosemide on pulmonary blood flow distribution in resting and exercising horses

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Erickson, H. H.; Bernard, S. L.; Glenny, R. W.; Fedde, M. R.; Polissar, N. L.; Basaraba, R. J.; Walther, S. M.; Gaughan, E. M.; McMurphy, R.; Hlastala, M. P.

1999-01-01

We determined the spatial distribution of pulmonary blood flow (PBF) with 15-micron fluorescent-labeled microspheres during rest and exercise in five Thoroughbred horses before and 4 h after furosemide administration (0.5 mg/kg iv). The primary finding of this study was that PBF redistribution occurred from rest to exercise, both with and without furosemide. However, there was less blood flow to the dorsal portion of the lung during exercise postfurosemide compared with prefurosemide. Furosemide did alter the resting perfusion distribution by increasing the flow to the ventral regions of the lung; however, that increase in flow was abated with exercise. Other findings included 1) unchanged gas exchange and cardiac output during rest and exercise after vs. before furosemide, 2) a decrease in pulmonary arterial pressure after furosemide, 3) an increase in the slope of the relationship of PBF vs. vertical height up the lung during exercise, both with and without furosemide, and 4) a decrease in blood flow to the dorsal region of the lung at rest after furosemide. Pulmonary perfusion variability within the lung may be a function of the anatomy of the pulmonary vessels that results in a predominantly fixed spatial pattern of flow distribution.

Analysis of blood flow dynamics in the abdominal aorta based on MR images

International Nuclear Information System (INIS)

Shimamura, Koumei; Tsubota, Kenichi; Ryu, Hiroshi; Sugimoto, Koichi; Haneishi, Hideaki

2010-01-01

Images of the abdominal aorta including peri-renal artery by PCMRA (phase contrast magnetic resonance angiography) were analyzed to calculate WSS (wall shear stress) and its OSI (oscillatory shear index) in order to visually elucidate the cause of aneurysm formation. PCMRA was conducted for acquisitions of vascular morphology in one cardiac cycle of a healthy male 30s with cardiac gating, and of blood flow rates from 3 directions. Images were median-filtered to reduce noises and regions of interest of rectangular parallelepiped were defined to involve the aorta. WSS, the parameter representing the intensity of friction stress to the vessel wall of blood flow, and OSI, the degree of oscillatory WSS change, were calculated firstly by the reported Snake model for the vessel morphology and then by applying its local information to blood flow rate information from 3 directions. Color-displayed images revealed that both WSS and OS were high at the highest incidental region of aortic aneurysm formation around the peri-renal artery. The finding was in good agreement with the result of computed bio-dynamic simulation that the strong WSS by elevated swirling of blood flow is generated at the region. Thus WSS and OS can be significant factors of aneurismal formation, which should be further confirmed from aspects of increased case number and precision. (T.T.)

Effects of dipyridamole and aminophylline on hemodynamics, regional myocardial blood flow and thallium-201 washout in the setting of a critical coronary stenosis

International Nuclear Information System (INIS)

Granato, J.E.; Watson, D.D.; Belardinelli, L.; Cannon, J.M.; Beller, G.A.

1990-01-01

Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg after intravenous administration of dipyridamole. In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal

Blood flow velocity measurements in chicken embryo vascular network via PIV approach

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Kurochkin, Maxim A.; Stiukhina, Elena S.; Fedosov, Ivan V.; Tuchin, Valery V.

2018-04-01

A method for measuring of blood velocity in the native vasculature of a chick embryo by the method of micro anemometry from particle images (μPIV) is improved. A method for interrogation regions sorting by the mask of the vasculature is proposed. A method for sorting of the velocity field of capillary blood flow is implemented. The in vitro method was evaluated for accuracy in a glass phantom of a blood vessel with a diameter of 50 μm and in vivo on the bloodstream of a chicken embryo, by comparing the transverse profile of the blood velocity obtained by the PIV method with the theoretical Poiseuille laminar flow profile.

Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia.

Science.gov (United States)

Wiegers, Evita C; Becker, Kirsten M; Rooijackers, Hanne M; von Samson-Himmelstjerna, Federico C; Tack, Cees J; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

2017-06-01

It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls ( n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic-hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia.

Hepatobiliary system functional analysis by blood flow and clearance delay model

International Nuclear Information System (INIS)

Aboltins, A.; Reinholds, E.

2002-01-01

A mathematical model for describing liver uptake-excretion is developed and approved. Model is based on different timing delays in hepatobiliary and blood flow system elements. Series of scintigraphic images with 99m Tc-mebrofenins or 99m Tc-HIDA taken with standard nuclear medicine gamma camera are used as the real data for calculations. The time-activity curves are obtained from many regions of human body - heart, liver, gallbladder, spleen, aorta, vein, etc. Both first pass and dynamic acquisition data are used. Results are calculated using real system parameters and compared to real scintigraphy data. Mathematical simulations are made to show difference of hepatobiliary system function at three main points: normal function, good blood flow with bad hepatic function and bad blood flow with good hepatic function. (authors)

Directly measuring spinal cord blood flow and spinal cord perfusion pressure via the collateral network: correlations with changes in systemic blood pressure.

Science.gov (United States)

Kise, Yuya; Kuniyoshi, Yukio; Inafuku, Hitoshi; Nagano, Takaaki; Hirayasu, Tsuneo; Yamashiro, Satoshi

2015-01-01

During thoracoabdominal surgery in which segmental arteries are sacrificed over a large area, blood supply routes from collateral networks have received attention as a means of avoiding spinal cord injury. The aim of this study was to investigate spinal cord blood supply through a collateral network by directly measuring spinal cord blood flow and spinal cord perfusion pressure experimentally. In beagle dogs (n = 8), the thoracoabdominal aorta and segmental arteries L1-L7 were exposed, and a temporary bypass was created for distal perfusion. Next, a laser blood flow meter was placed on the spinal dura mater in the L5 region to measure the spinal cord blood flow. The following were measured simultaneously when the direct blood supply from segmental arteries L2-L7 to the spinal cord was stopped: mean systemic blood pressure, spinal cord perfusion pressure (blood pressure within the aortic clamp site), and spinal cord blood flow supplied via the collateral network. These variables were then investigated for evidence of correlations. Positive correlations were observed between mean systemic blood pressure and spinal cord blood flow during interruption of segmental artery flow both with (r = 0.844, P flow with and without distal perfusion (r = 0.803, P network from outside the interrupted segmental arteries, and high systemic blood pressure (∼1.33-fold higher) was needed to obtain the preclamping spinal cord blood flow, whereas 1.68-fold higher systemic blood pressure was needed when distal perfusion was halted. Spinal cord blood flow is positively correlated with mean systemic blood pressure and spinal cord perfusion pressure under spinal cord ischemia caused by clamping a wide range of segmental arteries. In open and endovascular thoracic and thoracoabdominal surgery, elevating mean systemic blood pressure is a simple and effective means of increasing spinal cord blood flow, and measuring spinal cord perfusion pressure seems to be useful for monitoring

Evaluation of regional pulmonary blood flow in mitral valvular heart disease using single-pass radionuclide angiocardiography

International Nuclear Information System (INIS)

Chang-Soon Koh; Byung Tae Kim; Myung Chul Lee; Bo Yeon Cho

1982-01-01

Pulmonary hypertension in mitral valvular cardiac disease has been evaluated in 122 patients by a modified upper lung/lower count ratio using single-pass radionuclide angiocardiography. The mean upper lung/lower lung radio correlates well with pulmonary artery mean (r=0.483) and wedge pressure (r=0.804). After correction surgery of the cardiac valve, the ratio decreases and returns to normal range in patients judged clinically to have good surgical benifit. This modified method using single-pass technique provides additional simple, reproducible and nontraumatic results of regional pulmonary blood flow and appears to be correlated with the degree of pulmonary hypertension in mitral heart disease

Blood cell interactions and segregation in flow.

Science.gov (United States)

Munn, Lance L; Dupin, Michael M

2008-04-01

For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allowing blood to perform a variety of critical functions. Our current understanding of these unusual flow properties of blood have been made possible by the ingenuity and diligence of a number of researchers, including Harry Goldsmith, who developed novel technologies to visualize and quantify the flow of blood at the level of individual cells. Here we summarize efforts in our lab to continue this tradition and to further our understanding of how blood cells interact with each other and with the blood vessel wall.

The evaluation of cerebral hemodynamics in patients with intracranial tumors by stable xenon CT; The effect of glycerol administration on regional cerebral blood flow

Energy Technology Data Exchange (ETDEWEB)

Shimoda, Masami; Kawamata, Fumio; Yamamoto, Masahiro; Ohsuga, Hitoshi; Hidaka, Mitsuru; Oda, Shinri; Shibuya, Naoki; Yamamoto, Isao; Sato, Osamu (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)

1989-04-01

In evaluating cerebral regional blood flow (rCBF), stable xenon-enhanced tomography (XeCT) study associated with simultaneous blood sampling was applied in 15 cases of intracranial neoplasms. The effect of intravenous glycerol infusion on rCBF was also investigated. The results indicated that intratumoral rCBF values were not only variable and unrelated to their histological types and grades, but also were not correlated with the vascularity of the lesion as demonstrated by angiography. When a tumor mass was enhanced after the injection of iodinated contrast media, it proved to be useful in distinguishing tumor mass and its associated edema that the rCBF of the peritumoral edematous region was predominantly low (10{plus minus}5 ml/100 g/min). The regional cerebral blood flow in remote areas, both ipsilateral and contralateral to the lesion, was low in value, and there was no statistical significance between affected and sound sides. Following glycerol administration, rCBF was increased in the whole intracranial region, but not inside of the neoplasm, particularly when the intracranial pressure (ICP) was increased. It was assumed that the elevated rCBF after glycerol administration was due to the increase in the cerebral perfusion pressure resulting from the ICP reduction, the hemodilution effect, cerebral vessel dilatation after metabolic acidosis, and/or mechanically rectified microcirculation after edema reduction. (author).

Peak-counts blood flow model-errors and limitations

International Nuclear Information System (INIS)

Mullani, N.A.; Marani, S.K.; Ekas, R.D.; Gould, K.L.

1984-01-01

The peak-counts model has several advantages, but its use may be limited due to the condition that the venous egress may not be negligible at the time of peak-counts. Consequently, blood flow measurements by the peak-counts model will depend on the bolus size, bolus duration, and the minimum transit time of the bolus through the region of interest. The effect of bolus size on the measurement of extraction fraction and blood flow was evaluated by injecting 1 to 30ml of rubidium chloride in the femoral vein of a dog and measuring the myocardial activity with a beta probe over the heart. Regional blood flow measurements were not found to vary with bolus sizes up to 30ml. The effect of bolus duration was studied by injecting a 10cc bolus of tracer at different speeds in the femoral vein of a dog. All intravenous injections undergo a broadening of the bolus duration due to the transit time of the tracer through the lungs and the heart. This transit time was found to range from 4-6 second FWHM and dominates the duration of the bolus to the myocardium for up to 3 second injections. A computer simulation has been carried out in which the different parameters of delay time, extraction fraction, and bolus duration can be changed to assess the errors in the peak-counts model. The results of the simulations show that the error will be greatest for short transit time delays and for low extraction fractions

Aerobic fitness is associated with greater hippocampal cerebral blood flow in children

Directory of Open Access Journals (Sweden)

Laura Chaddock-Heyman

2016-08-01

Full Text Available The present study is the first to investigate whether cerebral blood flow in the hippocampus relates to aerobic fitness in children. In particular, we used arterial spin labeling (ASL perfusion MRI to provide a quantitative measure of blood flow in the hippocampus in 73 7- to 9-year-old preadolescent children. Indeed, aerobic fitness was found to relate to greater perfusion in the hippocampus, independent of age, sex, and hippocampal volume. Such results suggest improved microcirculation and cerebral vasculature in preadolescent children with higher levels of aerobic fitness. Further, aerobic fitness may influence how the brain regulates its metabolic demands via blood flow in a region of the brain important for learning and memory. To add specificity to the relationship of fitness to the hippocampus, we demonstrate no significant association between aerobic fitness and cerebral blood flow in the brainstem. Our results reinforce the importance of aerobic fitness during a critical period of child development.

Cerebral blood flow autoregulation is impaired in schizophrenia: A pilot study.

Science.gov (United States)

Ku, Hsiao-Lun; Wang, Jiunn-Kae; Lee, Hsin-Chien; Lane, Timothy Joseph; Liu, I-Chao; Chen, Yung-Chan; Lee, Yao-Tung; Lin, I-Cheng; Lin, Chia-Pei; Hu, Chaur-Jong; Chi, Nai-Fang

2017-10-01

Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of the participants had a history of cardiovascular diseases, hypertension, or diabetes. All participants underwent 10-min blood pressure and cerebral blood flow recording through finger plethysmography and Doppler ultrasonography, respectively. Cerebral autoregulation was assessed by analyzing two autoregulation indices: the mean blood pressure and cerebral blood flow correlation coefficient (Mx), and the phase shift between the waveforms of blood pressure and cerebral blood flow determined using transfer function analysis. Compared with the controls, the patients had a significantly higher Mx (0.257 vs. 0.399, p=0.036) and lower phase shift (44.3° vs. 38.7° in the 0.07-0.20Hz frequency band, p=0.019), which indicated impaired maintenance of constant cerebral blood flow and a delayed cerebrovascular autoregulatory response. Impaired cerebral autoregulation may be caused by schizophrenia and may not be an artifact of coexisting medical conditions. The mechanism underlying impaired cerebral autoregulation in schizophrenia and its probable role in the development of cerebrovascular diseases require further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

FDG metabolism and uptake versus blood flow in women with untreated primary breast cancers

International Nuclear Information System (INIS)

Zasadny, Kenneth R.; Tatsumi, Mitsuaki; Wahl, Richard L.

2003-01-01

The aim of this study was to determine the relationship between tumor blood flow and glucose utilization in women with untreated primary breast carcinomas. Noninvasive determinations of blood flow and glucose utilization with positron emission tomography (PET) were performed in 101 regions of tumor from nine women with untreated primary breast carcinoma. [ 15 O]H 2 O PET scans of tumor blood flow were compared with fluorine-18 fluoro-2-deoxy-D-glucose (FDG) PET scans of tumor glucose metabolism. Modeling of multiple parameters was undertaken and flow and glucose utilization compared. Mean whole-tumor blood flow was 14.9 ml dl -1 min -1 , but ranged from 7.6 to 29.2 ml dl -1 min -1 . Mean whole-tumor standardized uptake value corrected for lean body mass, SUV-lean (50-60 min), was 2.32±0.19 while mean K i was 1.2 ml dl -1 min -1 for FDG. SUV-lean and blood flow were strongly correlated (r=0.82, P=0.007) as were K 1 for FDG and flow (r=0.84, P=0.004). In these women with untreated breast cancers, FDG uptake (SUV-lean) and tumor blood flow are strongly correlated. The slope of FDG uptake versus blood flow appears higher at low flow rates, suggesting the possible presence of areas of tumor hypoxia. (orig.)

SPECT myocardial blood flow quantitation toward clinical use: a comparative study with {sup 13}N-Ammonia PET myocardial blood flow quantitation

Energy Technology Data Exchange (ETDEWEB)

Hsu, Bailing [University of Missouri-Columbia, Nuclear Science and Engineering Institute, Columbia, Missouri (United States); Hu, Lien-Hsin; Yang, Bang-Hung; Ting, Chien-Hsin; Huang, Wen-Sheng [Taipei Veterans General Hospital, Department of Nuclear Medicine, Taipei (China); Chen, Lung-Ching [Shin Kong Wu-Ho Su Memorial Hospital, Division of Cardiology, Taipei (China); Chen, Yen-Kung [Shin Kong Wu-Ho Su Memorial Hospital, Department of Nuclear Medicine, Taipei (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); Wu, Tao-Cheng [National Yang-Ming University, Cardiovascular Research Center, Taipei (China)

2017-01-15

The aim of this study was to evaluate the accuracy of myocardial blood flow (MBF) quantitation of {sup 99m}Tc-Sestamibi (MIBI) single photon emission computed tomography (SPECT) compared with {sup 13}N-Ammonia (NH3) position emission tomography (PET) on the same cohorts. Recent advances of SPECT technologies have been applied to develop MBF quantitation as a promising tool to diagnose coronary artery disease (CAD) for areas where PET MBF quantitation is not available. However, whether the SPECT approach can achieve the same level of accuracy as the PET approach for clinical use still needs further investigations. Twelve healthy volunteers (HVT) and 16 clinical patients with CAD received both MIBI SPECT and NH3 PET flow scans. Dynamic SPECT images acquired with high temporary resolution were fully corrected for physical factors and processed to quantify K1 using the standard compartmental modeling. Human MIBI tracer extraction fraction (EF) was determined by comparing MIBI K1 and NH3 flow on the HVT group and then used to convert flow values from K1 for all subjects. MIBI and NH3 flow values were systematically compared to validate the SPECT approach. The human MIBI EF was determined as [1.0-0.816*exp(-0.267/MBF)]. Global and regional MBF and myocardial flow reserve (MFR) of MIBI SPECT and NH3 PET were highly correlated for all subjects (global R{sup 2}: MBF = 0.92, MFR = 0.78; regional R{sup 2}: MBF ≥ 0.88, MFR ≥ 0.71). No significant differences for rest flow, stress flow, and MFR between these two approaches were observed (All p ≥ 0.088). Bland-Altman plots overall revealed small bias between MIBI SPECT and NH3 PET (global: ΔMBF = -0.03Lml/min/g, ΔMFR = 0.07; regional: ΔMBF = -0.07 - 0.06, ΔMFR = -0.02 - 0.22). Quantitation with SPECT technologies can be accurate to measure myocardial blood flow as PET quantitation while comprehensive imaging factors of SPECT to derive the variability between these two approaches were fully addressed and corrected

SPECT myocardial blood flow quantitation toward clinical use: a comparative study with "1"3N-Ammonia PET myocardial blood flow quantitation

International Nuclear Information System (INIS)

Hsu, Bailing; Hu, Lien-Hsin; Yang, Bang-Hung; Ting, Chien-Hsin; Huang, Wen-Sheng; Chen, Lung-Ching; Chen, Yen-Kung; Hung, Guang-Uei; Wu, Tao-Cheng

2017-01-01

The aim of this study was to evaluate the accuracy of myocardial blood flow (MBF) quantitation of "9"9"mTc-Sestamibi (MIBI) single photon emission computed tomography (SPECT) compared with "1"3N-Ammonia (NH3) position emission tomography (PET) on the same cohorts. Recent advances of SPECT technologies have been applied to develop MBF quantitation as a promising tool to diagnose coronary artery disease (CAD) for areas where PET MBF quantitation is not available. However, whether the SPECT approach can achieve the same level of accuracy as the PET approach for clinical use still needs further investigations. Twelve healthy volunteers (HVT) and 16 clinical patients with CAD received both MIBI SPECT and NH3 PET flow scans. Dynamic SPECT images acquired with high temporary resolution were fully corrected for physical factors and processed to quantify K1 using the standard compartmental modeling. Human MIBI tracer extraction fraction (EF) was determined by comparing MIBI K1 and NH3 flow on the HVT group and then used to convert flow values from K1 for all subjects. MIBI and NH3 flow values were systematically compared to validate the SPECT approach. The human MIBI EF was determined as [1.0-0.816*exp(-0.267/MBF)]. Global and regional MBF and myocardial flow reserve (MFR) of MIBI SPECT and NH3 PET were highly correlated for all subjects (global R"2: MBF = 0.92, MFR = 0.78; regional R"2: MBF ≥ 0.88, MFR ≥ 0.71). No significant differences for rest flow, stress flow, and MFR between these two approaches were observed (All p ≥ 0.088). Bland-Altman plots overall revealed small bias between MIBI SPECT and NH3 PET (global: ΔMBF = -0.03Lml/min/g, ΔMFR = 0.07; regional: ΔMBF = -0.07 - 0.06, ΔMFR = -0.02 - 0.22). Quantitation with SPECT technologies can be accurate to measure myocardial blood flow as PET quantitation while comprehensive imaging factors of SPECT to derive the variability between these two approaches were fully addressed and corrected. (orig.)

Regional cerebral blood flow and cognitive function in patients with obsessive-compulsive disorder

Directory of Open Access Journals (Sweden)

Huirong Guo

2014-01-01

Full Text Available Objective: To explore the relationship between regional cerebral blood flow (CBF and cognitive function in obsessive-compulsive disorder (OCD. Method: Single-photon emission computed tomography (SPECT was performed for 139 OCD patients and 139 controls, and the radioactivity rate (RAR was calculated. Cognitive function was assessed by the Wisconsin Card Sorting Test (WCST. Results: The RARs of the prefrontal, anterior temporal, and right occipital lobes were higher in patients than controls. For the WCST, correct and classification numbers were significantly lower, and errors and persistent errors were significantly higher in OCD patients. Right prefrontal lobe RAR was negatively correlated with correct numbers, right anterior temporal lobe RAR was positively correlated with errors, and the RARs of the right prefrontal lobe and left thalamus were positively correlated with persistent errors. Conclusion: OCD patients showed higher CBF in the prefrontal and anterior temporal lobes, suggesting that these areas may be related with cognitive impairment.

Stimulus rate dependence of regional cerebral blood flow in human striate cortex, demonstrated by positron emission tomography

International Nuclear Information System (INIS)

Fox, P.T.; Raichle, M.E.

1984-01-01

The purpose of this investigation was to determine the relationship between the repetition rate of a simple sensory stimulus and regional cerebral blood flow (rCBF) in the human brain. Positron emission tomography (PET), using intravenously administered H 2 ( 15 )O as the diffusible blood-flow tracer, was employed for all CBF measurements. The use of H 2 ( 15 )O with PET allowed eight CBF measurements to be made in rapid sequence under multiple stimulation conditions without removing the subject from the tomograph. Nine normal volunteers each underwent a series of eight H2( 15 )O PET measurements of CBF. Initial and final scans were made during visual deprivation. The six intervening scans were made during visual activation with patterned-flash stimuli given in random order at 1.0-, 3.9-, 7.8-, 15.5-, 33.1-, and 61-Hz repetition rates. The region of greatest rCBF increase was determined. Within this region the rCBF was determined for every test condition and then expressed as the percentage change from the value of the initial unstimulated scan (rCBF% delta). In every subject, striate cortex rCBF% delta varied systematically with stimulus rate. Between 0 and 7.8 Hz, rCBF% delta was a linear function of stimulus repetition rate. The rCBF response peaked at 7.8 Hz and then declined. The rCBF% delta during visual stimulation was significantly greater than that during visual deprivation for every stimulus rate except 1.0 Hz. The anatomical localization of the region of peak rCBF response was determined for every subject to be the mesial occipital lobes along the calcarine fissure, primary visual cortex. Stimulus rate is a significant determinant of rCBF response in the visual cortex. Investigators of brain responses to selective activation procedures should be aware of the potential effects of stimulus rate on rCBF and other measurements of cerebral metabolism

Glial and neuronal control of brain blood flow

DEFF Research Database (Denmark)

Attwell, David; Buchan, Alastair M; Charpak, Serge

2010-01-01

Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now...... recognized that neurotransmitter-mediated signalling has a key role in regulating cerebral blood flow, that much of this control is mediated by astrocytes, that oxygen modulates blood flow regulation, and that blood flow may be controlled by capillaries as well as by arterioles. These conceptual shifts...

Collateral blood flow in different cerebrovascular hierarchy provides endogenous protection in cerebral ischemia.

Science.gov (United States)

Luo, Chuanming; Liang, Fengyin; Ren, Huixia; Yao, Xiaoli; Liu, Qiang; Li, Mingyue; Qin, Dajiang; Yuan, Ti-Fei; Pei, Zhong; Su, Huanxing

2017-11-01

Collateral blood flow as vascular adaptions to focal cerebral ischemia is well recognized. However, few studies directly investigate the dynamics of collateral vessel recruitment in vivo and little is known about the effect of collateral blood flow in different cerebrovascular hierarchy on the neuropathology after focal ischemic stroke. Here, we report that collateral blood flow is critically involved in blood vessel compensations following regional ischemia. We occluded a pial arteriole using femtosecond laser ablating under the intact thinned skull and documented the changes of collateral flow around the surface communication network and between the surface communication network and subsurface microcirculation network using in vivo two photon microscopy imaging. Occlusion of the pial arteriole apparently increased the diameter and collateral blood flow of its leptomeningeal anastomoses, which significantly reduced the cortical infarction size. This result suggests that the collateral flow via surface communicating network connected with leptomeningeal anastomoses could greatly impact on the extent of infarction. We then further occluded the target pial arteriole and all of its leptomeningeal anastomoses. Notably, this type of occlusion led to reversals of blood flow in the penetrating arterioles mainly proximal to the occluded pial arteriole in a direction from the subsurface microcirculation network to surface arterioles. Interesting, the cell death in the area of ischemic penumbra was accelerated when we performed occlusion to cease the reversed blood flow in those penetrating arterioles, suggesting that the collateral blood flow from subsurface microcirculation network exerts protective roles in delaying cell death in the ischemic penumbra. In conclusion, we provide the first experimental evidence that collateral blood vessels at different cerebrovascular hierarchy are endogenously compensatory mechanisms in brain ischemia. © 2016 International Society of

Regional cerebral blood flow during light sleep--a H(2)(15)O-PET study

DEFF Research Database (Denmark)

Kjaer, Troels W; Law, Ian; Wiltschiøtz, Gordon

2002-01-01

to other forms of altered awareness, for example, relaxation meditation than to deeper sleep stages. We are of the opinion that stage-1 sleep represents the dreaming state of wakefulness, while rapid eye movement (REM) sleep reflects the dreaming state of the unaware, sleeping brain.......This is the first report on the distribution of regional cerebral blood flow (rCBF) changes during stage-1 sleep or somnolence. Two hypotheses were tested: (A) that rCBF differed between the awake relaxed state and stage-1 sleep, (B) that hypnagogic hallucinations frequently experienced at sleep...... onset would be accompanied by measurable changes in rCBF using positron emission tomography (PET). Eight subjects were PET-scanned with (15)O-labeled water injection in three conditions: awake, stage-1 sleep with reportable experiences and stage-1 sleep without reportable experiences...

Evaluation of hepatic blood flow using 99mTc-GSA in rats with hepatic blood flow manipulation

International Nuclear Information System (INIS)

Hiraguchi, Etsuo

1995-01-01

Blood clearance and hepatic uptake parameters of 99m Tc-DTPA-galactosyl human serum albumin ( 99m Tc-GSA) were evaluated in two groups of rats, normal liver group and CCl 4 induced chronic liver injury group. In each group, four subgroups were classified as follows: simple laparotomy (LAP), hepatic artery ligation (HAL), portal vein ligation (PVL) and both hepatic artery and portal vein ligation (HAL+PVL). 99m Tc-GSA was intravenously injected (50 μg/100 g B.W.) to rats. Heart and liver were targetted as region of interest and time activity curves (TACs) were obtained. The blood clearance parameters (HH4 and Kd) and the hepatic uptake parameters (LHL4 and Ku) were calculated from these TACs. In normal liver group, the mean HH4 of LAP was significantly different from those of PVL and HAL+PVL. Similarly, the other three parameters (LHL4, Kd and Ku) of LAP were significantly different from those of PVL and HAL+PVL. CCl 4 induced chronic liver injury group showed significant difference on all four parameters in four subgroups. Hepatic tissue blood flow rates (HTBFR) calculated by Laser Doppler flowmeter correlated well with 99m Tc-GSA parameters in both groups. These results suggest that 99m Tc-GSA is useful to estimate hepatic blood flow not only in rats with normal liver, but also in rats with CCl 4 induced chronic liver injury. (author)

Regional cerebral blood flow in Parkinson's disease measured with N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) SPECT

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Odano, Ikuo; Nishihara, Mamiko; Hayashi, Hiroko; Higuchi, Shoichi; Sakai, Kunio [Niigata Univ. (Japan). School of Medicine; Ishikawa, Atsushi; Ibayashi, Katsuhiko

1992-09-01

N-isopropyl-p-[[sup 123]I]iodoamphetamine (IMP) SPECT studies were performed on 21 patients (13 females; 45-73 yrs) with idiopathic Parkinson's disease (PD) and 10 age-matched normal controls (39-69 yrs). Regional cerebral blood flow (rCBF) was quantitatively measured by the arterial blood sampling method. When compared with normal controls, global CBF, and rCBF in the frontal cortex and in the basal ganglia were reduced 22.1% (p<0.01), 25.0% (p<0.05) and 25.6% (p<0.01), respectively. The reduction of rCBF in the basal ganglia was significantly correlated (p<0.05) with symptoms such as gait disturbance, frozen gait and motor disability score. However, no significant correlation was observed between the severity of dementia and any regional reduction of CBF, including the frontal or parietal cortices. These data show that the severity of dementia in PD may be related to other factors but not with CBF. Quantification of rCBF with [sup 123]I-IMP SPECT imaging is useful for evaluation and follow-up of patients with PD. (author).

The effect of partial portal decompression on portal blood flow and effective hepatic blood flow in man: a prospective study.

Science.gov (United States)

Rosemurgy, A S; McAllister, E W; Godellas, C V; Goode, S E; Albrink, M H; Fabri, P J

1995-12-01

With the advent of transjugular intrahepatic porta-systemic stent shunt and the wider application of the surgically placed small diameter prosthetic H-graft portacaval shunt (HGPCS), partial portal decompression in the treatment of portal hypertension has received increased attention. The clinical results supporting the use of partial portal decompression are its low incidence of variceal rehemorrhage due to decreased portal pressures and its low rate of hepatic failure, possibly due to maintenance of blood flow to the liver. Surprisingly, nothing is known about changes in portal hemodynamics and effective hepatic blood flow following partial portal decompression. To prospectively evaluate changes in portal hemodynamics and effective hepatic blood flow brought about by partial portal decompression, the following were determined in seven patients undergoing HGPCS: intraoperative pre- and postshunt portal vein pressures and portal vein-inferior vena cava pressure gradients, intraoperative pre- and postshunt portal vein flow, and pre- and postoperative effective hepatic blood flow. With HGPCS, portal vein pressures and portal vein-inferior vena cava pressure gradients decreased significantly, although portal pressures remained above normal. In contrast to the significant decreases in portal pressures, portal vein blood flow and effective hepatic blood flow do not decrease significantly. Changes in portal vein pressures and portal vein-inferior vena cava pressure gradients are great when compared to changes in portal vein flow and effective hepatic blood flow. Reduction of portal hypertension with concomitant maintenance of hepatic blood flow may explain why hepatic dysfunction is avoided following partial portal decompression.

SPECT with [99mTc]-d,l-hexamethyl-propylene amine oxime (HM-PAO) compared with regional cerebral blood flow measured by PET

DEFF Research Database (Denmark)

Yonekura, Y; Nishizawa, S; Mukai, Thomas Søgaard

1988-01-01

In order to validate the use of technetium-99m-d,l-hexamethylpropyleneamine oxime (HM-PAO) as a flow tracer, a total of 21 cases were studied with single photon emission computerized tomography (SPECT), and compared to regional cerebral blood flow (rCBF) measured by position emission tomography...... (PET) using the oxygen-15 CO2 inhalation technique. Although HM-PAO SPECT and rCBF PET images showed a similar distribution pattern the HM-PAO SPECT image showed less contrast between high and low activity flow regions than the rCBF image and a nonlinear relationship between HM-PAO activity and r......CBF was shown. Based on the assumption of flow-dependent backdiffusion of HM-PAO from the brain, we applied a "linearization algorithm" to correct the HM-PAO SPECT images. The corrected HM-PAO SPECT images revealed a good linear correlation with rCBF (r = 0.901, p less than 0.001). The results indicated HM-PAO...

A study of the acute effect of smoking on cerebral blood flow using 99mTc-ECD SPET

International Nuclear Information System (INIS)

Yamamoto, Yuka; Nishiyama, Yoshihiro; Monden, Toshihide; Satoh, Katashi; Ohkawa, Motoomi

2003-01-01

Cigarette smoking is known to be associated with atherosclerosis, is an important risk factor for stroke and has other serious effects. The aim of this study was to evaluate the acute effect of cigarette smoking on cerebral blood flow using statistical parametric mapping (SPM). Ten healthy volunteers with a smoking habit were studied using technetium-99m-labelled ethylcysteinate dimer single-photon emission tomography (SPET). We evaluated the regional cerebral blood flow under the smoking and resting states. The regional cerebral blood flow on smoking-activated SPET was significantly decreased in the whole brain as compared with that on resting SPET. Our findings therefore suggest that one of the acute effects of cigarette smoking is to induce a diffuse decrease in cerebral blood flow. (orig.)

Blood flow autoregulation in pedicled flaps

DEFF Research Database (Denmark)

Bonde, Christian T; Holstein-Rathlou, Niels-Henrik; Elberg, Jens J

2009-01-01

was to evaluate if, and to what extent, a tissue flap could compensate a reduction in blood flow due to an acute constriction of the feed artery. Further, we wanted to examine the possible role of smooth muscle L-type calcium channels in the autoregulatory mechanism by pharmacological intervention with the L......, the flow in the pedicle was reduced and the flow was recorded. RESULTS: The flaps showed a strong autoregulatory response with complete compensation for flow reductions of up to 70-80%. Infusion of nimodipine caused a 28+/-10% increase in blood flow and removed the autoregulation. Papaverine caused...... a further increase in blood flow by 61+/-19%. The time control experiments proved that the experimental procedure was reproducible and stable over time. CONCLUSIONS: A tissue flap can nearly completely compensate for repeated flow reductions of up to 70-80%. This is due to a decrease in the peripheral...

Blood flow patterns underlie developmental heart defects.

Science.gov (United States)

Midgett, Madeline; Thornburg, Kent; Rugonyi, Sandra

2017-03-01

Although cardiac malformations at birth are typically associated with genetic anomalies, blood flow dynamics also play a crucial role in heart formation. However, the relationship between blood flow patterns in the early embryo and later cardiovascular malformation has not been determined. We used the chicken embryo model to quantify the extent to which anomalous blood flow patterns predict cardiac defects that resemble those in humans and found that restricting either the inflow to the heart or the outflow led to reproducible abnormalities with a dose-response type relationship between blood flow stimuli and the expression of cardiac phenotypes. Constricting the outflow tract by 10-35% led predominantly to ventricular septal defects, whereas constricting by 35-60% most often led to double outlet right ventricle. Ligation of the vitelline vein caused mostly pharyngeal arch artery malformations. We show that both cardiac inflow reduction and graded outflow constriction strongly influence the development of specific and persistent abnormal cardiac structure and function. Moreover, the hemodynamic-associated cardiac defects recapitulate those caused by genetic disorders. Thus our data demonstrate the importance of investigating embryonic blood flow conditions to understand the root causes of congenital heart disease as a prerequisite to future prevention and treatment. NEW & NOTEWORTHY Congenital heart defects result from genetic anomalies, teratogen exposure, and altered blood flow during embryonic development. We show here a novel "dose-response" type relationship between the level of blood flow alteration and manifestation of specific cardiac phenotypes. We speculate that abnormal blood flow may frequently underlie congenital heart defects. Copyright © 2017 the American Physiological Society.

Neuromodulation therapy does not influence blood flow distribution or left-ventricular dynamics during acute myocardial ischemia.

Science.gov (United States)

Kingma, J G; Linderoth, B; Ardell, J L; Armour, J A; DeJongste, M J; Foreman, R D

2001-08-13

Electrical stimulation of the dorsal aspect of the upper thoracic spinal cord is used increasingly to treat patients with angina pectoris refractory to conventional therapeutic strategies. The purpose of this study was to determine whether spinal cord stimulation (SCS) in dogs affects regional myocardial blood flow and left-ventricular (LV) function before and during transient obstruction of the left anterior descending coronary artery (LAD). In anesthetized dogs, regional myocardial blood flow distribution was determined using radiolabeled microspheres and left-ventricular function was measured by impedance-derived pressure-volume loops. SCS was accomplished by stimulating the dorsal T1-T2 segments of the spinal cord using epidural bipolar electrodes at 90% of motor threshold (MT) (50 Hz, 0.2-ms duration). Effects of 5-min SCS were assessed under basal conditions and during 4-min occlusion of the LAD. SCS alone evoked no change in regional myocardial blood flow or cardiovascular indices. Transient LAD occlusion significantly diminished blood flow within ischemic, but not in non-ischemic myocardial tissue. Left ventricular pressure-volume loops were shifted rightward during LAD occlusion. Cardiac indices were altered similarly during LAD occlusion and concurrent SCS. SCS does not influence the distribution of blood flow within the non-ischemic or ischemic myocardium. Nor does it modify LV pressure-volume dynamics in the anesthetized experimental preparation.

Caffeine and human cerebral blood flow: A positron emission tomography study

International Nuclear Information System (INIS)

Cameron, O.G.; Modell, J.G.; Hariharan, M.

1990-01-01

Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p a CO 2 and increased systolic blood pressure significantly; the change in p a CO 2 did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed

Caffeine and human cerebral blood flow: A positron emission tomography study

Energy Technology Data Exchange (ETDEWEB)

Cameron, O.G.; Modell, J.G.; Hariharan, M. (Univ. of Michigan Medical Center, Ann Arbor (USA))

1990-01-01

Positron emission tomography (PET) was used to quantify the effect of caffeine on whole brain and regional cerebral blood flow (CBF) in humans. A mean dose of 250 mg of caffeine produced approximately a 30% decrease in whole brain CBF; regional differences in caffeine effect were not observed. Pre-caffeine CBF strongly influenced the magnitude of the caffeine-induced decrease. Caffeine decreased p{sub a}CO{sub 2} and increased systolic blood pressure significantly; the change in p{sub a}CO{sub 2} did not account for the change in CBF. Smaller increases in diastolic blood pressure, heart rate, plasma epinephrine and norepinephrine, and subjectively reported anxiety were also observed.

Three-dimensional visualization of myocardial motion and blood flow with cine-MR images

International Nuclear Information System (INIS)

Oshiro, Osamu; Matani, Ayumu; Chihara, Kunihiro; Mikami, Taisei; Kitabatake, Akira.

1997-01-01

This paper describes a three-dimensional (3D) reconstruction and presentation method to visualize myocardial motion and blood flow in a heart using cine-MR (magnetic resonance) images. Firstly, the region of myocardium and blood were segmented with certain threshold gray values. Secondly, some slices were interpolated linearly to reconstruct a 3D static image. Finally, a 3D dynamic image was presented with displaying the 3D static images sequentially. The experimental results indicate that this method enables to visualize not only normal but also abnormal blood flow in cine-mode. (author)

Comparative study of Newtonian physiological blood flow through normal and stenosed carotid artery

Science.gov (United States)

Rahman, Mohammad Matiur; Hossain, Md. Anwar; Mamun, Khairuzzaman; Akhter, Most. Nasrin

2017-06-01

A numerical simulation is performed to investigate Newtonian physiological flows behavior on three dimensional idealized carotid artery (CA) and single stenosed (75% by area) carotid artery(SCA). The wall vessel is set as rigid during simulation. Bifurcated blood vessel are simulated by using three-dimensional flow analysis. Physiological and parabolic velocity profiles are set out to fix the conditions of inlet boundaries of artery. In other hand, physiological waveform is an important part of compilation and it is successfully done by utilization of Fourier series having sixteen harmonics. The investigation has a Reynolds number range of 94 to 1120. Low Reynolds number k — ω model has been used as governing equation. The investigation has been carried out to characterize the flow behavior of blood in two geometry, namely, (i) Normal carotid artery (CA) and (ii) Stenosed carotid artery (SCA). The Newtonian model has been used to study the physics of fluid. The findings of the two models are thoroughly compared in order to observe there behavioral sequence of flows. The numerical results were presented in terms of velocity, pressure, wall shear stress distributions and cross sectional velocities as well as the streamlines contour. Stenosis disturbs the normal pattern of blood flow through the artery as reduced area. At stenosis region velocity and peak Reynolds number rapidly increase and Reynolds number reach transitional and turbulent region. These flow fluctuation and turbulence have bad effect to the blood vessel which makes to accelerate the progress of stenosis.

Three-dimensional imaging of absolute blood flow velocity and blood vessel position under low blood flow velocity based on Doppler signal information included in scattered light from red blood cells

Science.gov (United States)

Kyoden, Tomoaki; Akiguchi, Shunsuke; Tajiri, Tomoki; Andoh, Tsugunobu; Hachiga, Tadashi

2017-11-01

The development of a system for in vivo visualization of occluded distal blood vessels for diabetic patients is the main target of our research. We herein describe two-beam multipoint laser Doppler velocimetry (MLDV), which measures the instantaneous multipoint flow velocity and can be used to observe the blood flow velocity in peripheral blood vessels. By including a motorized stage to shift the measurement points horizontally and in the depth direction while measuring the velocity, the path of the blood vessel in the skin could be observed using blood flow velocity in three-dimensional space. The relationship of the signal power density between the blood vessel and the surrounding tissues was shown and helped us identify the position of the blood vessel. Two-beam MLDV can be used to simultaneously determine the absolute blood flow velocity distribution and identify the blood vessel position in skin.

Regional cerebral blood flow changes in patients with internet addiction.

Science.gov (United States)

Otte, Andreas

2016-01-01

Dear Editor, Internet addiction (IA) has become a severe challenge of our modern world today, though little is known about its pathology. In this context, the interesting study by Liu et al. in the May-August 2016 issue of HJNM using 99m Tc-labelled ethylene biyldicysteinate dimer single photon emission tomography (SPET) at rest and after pharmaceutical (adenosine) stress is more than welcomed. As this seems to be the first perfusion SPET study in this indication, the obtained data may be discussed carefully. There are mainly the following questions: a) Regional cerebral blood flow (rCBF): There is no description on how the rCBF was calculated: Was it scaled relatively to the whole brain mean value or to the cerebellar mean value? b) P value threshold and clusters: There is no indication of whether the authors are performing any kind of correction for multiple comparisons in the statistical parametric mapping (SPM) t-test. This, combined with the use of a really "liberal" voxel P value of only 0.01 could be subject to providing many false positive results. Generally a P value threshold of 0.001 should be used. In addition, there is no information related to the clusters. For the question of the validity of parametric statistical methods used for the analysis of functional neuroimaging data, we would like to mention the important recent paper by Eklund et al. 2016. c) Data analysis: The authors state (p. 97): "As some abnormal rCBF in adenosine-stressed state might relate with normal responses to adenosine compared to resting state, we excluded those regions that showed abnormal rCBF in stressed state in healthy controls (Table 4) from those in IA group (Table 5). The rest abnormal regions were compared between the IA group and the control group". For this, with SPM a flexible factorial design with all the data rather than only t-tests would have been interesting to find out whether the difference between the groups at stress is the same difference observed between

Regional cerebral blood flow and brain atrophy in senile dementia of Alzheimer type (SDAT). Comparing with multi-infarct dementia (MID), and aged control

Energy Technology Data Exchange (ETDEWEB)

Okada, K; Kobayashi, S; Yamaguchi, S; Kitani, M; Tsunematsu, T

1987-05-01

To investigate the relationship between the reduction of cerebal blood flow and brain atrophy in SDAT, these were measured in 13 cases of senile dementia of Alzheimer type, and compared to 15 cases of multi-infarct Dementia, 39 cases of lacunar infarction without dementia (non-demented CVD group) and 69 cases of aged normal control. Brain atrophy was evaluated by two-dimensional method on CT film by digitizer and regional cerebral blood flow (rCBF) was measured by /sup 133/Xe inhalation method. The degree of brain atrophy in SDAT was almost similar of that of MID. But it was more severe than that of non-demented group. MID showed the lowest rCBF among these groups. SDAT showed significantly lower rCBF than that of aged control, but rCBF in SDAT was equal to that of lacunar stroke without dementia. Focal reduction of cerebral blood flow in bilateral fronto-parietal and left occipital regions were observed in SDAT. Verbal intelligence score (Hasegawa's score) correlated with rCBF and brain atrophy index in MID, and a tendency of correlation between rCBF and brain atrophy in MID was also observed. However, there was no correlation among those indices in SDAT. These findings suggest that the loss of brain substance dose not correspond to the reduction of rCBF in SDAT and simultaneous measurement of rCBF and brain atrophy was useful to differ SDAT from MID.

Changes in regional cerebral blood flow during auditory cognitive tasks

International Nuclear Information System (INIS)

Ohyama, Masashi; Kitamura, Shin; Terashi, Akiro; Senda, Michio.

1993-01-01

In order to investigate the relation between auditory cognitive function and regional brain activation, we measured the changes in the regional cerebral blood flow (CBF) using positron emission tomography (PET) during the 'odd-ball' paradigm in ten normal healthy volunteers. The subjects underwent 3 tasks, twice for each, while the evoked potential was recorded. In these tasks, the auditory stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB from the earphones. Task A: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to only hear. Task B: the stimulus was a series of tones with 1000 Hz only, and the subject was instructed to push the button on detecting a tone. Task C: the stimulus was a series of pure tones delivered every 1.5 sec binaurally at 75 dB with a frequency of 1000 Hz (non-target) in 80% and 2000 Hz (target) in 20% at random, and the subject was instructed to push the button on detecting a target tone. The event related potential (P300) was observed in task C (Pz: 334.3±19.6 msec). At each task, the CBF was measured using PET with i.v. injection of 1.5 GBq of O-15 water. The changes in CBF associated with auditory cognition was evaluated by the difference between the CBF images in task C and B. Localized increase was observed in the anterior cingulate cortex (in all subjects), the bilateral associate auditory cortex, the prefrontal cortex and the parietal cortex. The latter three areas had a large individual variation in the location of foci. These results suggested the role of those cortical areas in auditory cognition. The anterior cingulate was most activated (15.0±2.24% of global CBF). This region was not activated in the condition of task B minus task A. The anterior cingulate is a part of Papez's circuit that is related to memory and other higher cortical function. These results suggested that this area may play an important role in cognition as well as in attention. (author)

Effect of basal forebrain stimulation on extracellular acetylcholine release and blood flow in the olfactory bulb.

Science.gov (United States)

Uchida, Sae; Kagitani, Fusako

2017-05-12

The olfactory bulb receives cholinergic basal forebrain input, as does the neocortex; however, the in vivo physiological functions regarding the release of extracellular acetylcholine and regulation of regional blood flow in the olfactory bulb are unclear. We used in vivo microdialysis to measure the extracellular acetylcholine levels in the olfactory bulb of urethane-anesthetized rats. Focal chemical stimulation by microinjection of L-glutamate into the horizontal limb of the diagonal band of Broca (HDB) in the basal forebrain, which is the main source of cholinergic input to the olfactory bulb, increased extracellular acetylcholine release in the ipsilateral olfactory bulb. When the regional cerebral blood flow was measured using laser speckle contrast imaging, the focal chemical stimulation of the HDB did not significantly alter the blood flow in the olfactory bulb, while increases were observed in the neocortex. Our results suggest a functional difference between the olfactory bulb and neocortex regarding cerebral blood flow regulation through the release of acetylcholine by cholinergic basal forebrain input.

Regional cerebral blood flow measurements by a noninvasive microsphere method using 123I-IMP. Comparison with the modified fractional uptake method and the continuous arterial blood sampling method

International Nuclear Information System (INIS)

Nakano, Seigo; Matsuda, Hiroshi; Tanizaki, Hiroshi; Ogawa, Masafumi; Miyazaki, Yoshiharu; Yonekura, Yoshiharu

1998-01-01

A noninvasive microsphere method using N-isopropyl-p-( 123 I)iodoamphetamine ( 123 I-IMP), developed by Yonekura et al., was performed in 10 patients with neurological diseases to quantify regional cerebral blood flow (rCBF). Regional CBF values by this method were compared with rCBF values simultaneously estimated from both the modified fractional uptake (FU) method using cardiac output developed by Miyazaki et al. and the conventional method with continuous arterial blood sampling. In comparison, we designated the factor which converted raw SPECT voxel counts to rCBF values as a CBF factor. A highly significant correlation (r=0.962, p<0.001) was obtained in the CBF factors between the present method and the continuous arterial blood sampling method. The CBF factors by the present method were only 2.7% higher on the average than those by the continuous arterial blood sampling method. There were significant correlation (r=0.811 and r=O.798, p<0.001) in the CBF factor between modified FU method (threshold for estimating total brain SPECT counts; 10% and 30% respectively) and the continuous arterial blood sampling method. However, the CBF factors of the modified FU method showed 31.4% and 62.3% higher on the average (threshold; 10% and 30% respectively) than those by the continuous arterial blood sampling method. In conclusion, this newly developed method for rCBF measurements was considered to be useful for routine clinical studies without any blood sampling. (author)

Regional cerebral blood flow of the patients with schizophrenia. A study using 99mTc-ECD SPECT at rest and activation

International Nuclear Information System (INIS)

Hu Ping; Wu Kening; Zeng Shiquan; Lin Zengtao; Yu Jinlong

1996-01-01

Regional cerebral blood flow (rCBF) changes of the patients with schizophrenia were observed. 99m Tc-ECD SPECT was performed on 22 patients with schizophrenia and 10 healthy volunteers at rest and activation with a cognitive task: a modified Wisconsin Card Sorting Test. At rest state, only 4 patients have abnormal rCBF pattern: left hemisphere over-perfusion relative to the right. A significant relative activation deficit in the left inferior prefrontal region was revealed in the patients during activation. The patients with schizophrenia may have frontal lobe dysfunction

Blood flow determinations utilizing digital densitometry

International Nuclear Information System (INIS)

Lois, F.; Mankovich, N.J.; Gomes, A.S.

1987-01-01

A method of obtaining relative and absolute blood flow measurements from digital densitometry was evaluated with a simulated vessel phantom and a hydrodynamic model. A digital vascular imaging system capable of acquisition in 512 2 and 1024 2 mode was used. Relative and absolute blood flow were measured using parameters derived from the densitometric curve. Since application of densitometric data to absolute flow measurements requires the vessel diameter, an algorithm for vessel size determination was created. Gray scale changes were demonstrated to be linearly related to contrast concentration. The variance of vessel size determination was significantly different in all combinations of 1024 2 and 512 2 imaging with 15 cm or 35 cm field size. The error in vessel size determination was significantly less using the larger 1024 2 matrix and the smaller 15 cm image intensifier field size, as shown by the smaller variance. In relative flow determinations, there was good correlation between the flow and four parameters of the densitometric curve with no significant differences between 512 2 and 1024 2 imaging. Absolute flow determinations had slightly lower correlation to actual flow but were not significantly different from relative flow determinations. Relative and absolute blood flow determinations can be performed adequately with either 512 2 or 1024 2 imaging. The increased accuracy in vessel size determination with 1024 2 imaging makes this high resolution system potentially perferable to determine absolute blood flow. (orig.)

Measurement of regional cerebral blood flow using one-point venous blood sampling and causality model. Evaluation by comparing with conventional continuous arterial blood sampling method

International Nuclear Information System (INIS)

Mimura, Hiroaki; Sone, Teruki; Takahashi, Yoshitake

2008-01-01

Optimal setting of the input function is essential for the measurement of regional cerebral blood flow (rCBF) based on the microsphere model using N-isopropyl-4-[ 123 I]iodoamphetamine ( 123 I-IMP), and usually the arterial 123 I-IMP concentration (integral value) in the initial 5 min is used for this purpose. We have developed a new convenient method in which 123 I-IMP concentration in arterial blood sample is estimated from that in venous blood sample. Brain perfusion single photon emission computed tomography (SPECT) with 123 I-IMP was performed in 110 cases of central nervous system disorders. The causality was analyzed between the various parameters of SPECT data and the ratio of octanol-extracted arterial radioactivity concentration during the first 5 min (Caoct) to octanol-extracted venous radioactivity concentration at 27 min after intravenous injection of 123 I-IMP (Cvoct). A high correlation was observed between the measured and estimated values of Caoct/Cvoct (r=0.856) when the following five parameters were included in the regression formula: radioactivity concentration in venous blood sampled at 27 min (Cv), Cvoct, Cvoct/Cv, and total brain radioactivity counts that were measured by a four-head gamma camera 5 min and 28 min after 123 I-IMP injection. Furthermore, the rCBF values obtained using the input parameters estimated by this method were also highly correlated with the rCBF values measured using the continuous arterial blood sampling method (r=0.912). These results suggest that this method would serve as the new, convenient and less invasive method of rCBF measurement in clinical setting. (author)

Bone blood flow and metabolism in humans

DEFF Research Database (Denmark)

Heinonen, Ilkka; Kemppainen, Jukka; Kaskinoro, Kimmo

2012-01-01

Human bone blood flow and metabolism during physical exercise remains poorly characterised. In the present study we measured femoral bone blood flow and glucose uptake in young healthy subjects by positron emission tomography in three separate protocols. In six women, blood flow was measured...... in femoral bone at rest and during one leg intermittent isometric exercise with increasing exercise intensities. In nine men, blood flow in femur was determined at rest and during dynamic one leg exercise, and two other physiological perturbations: moderate systemic hypoxia (14 O(2) ) at rest and during...... exercise, and during intra-femoral infusion of high-dose adenosine. Bone glucose uptake was measured at rest and during dynamic one leg exercise in five men. The results indicate that isometric exercise increased femoral bone blood flow from rest (1.8 ± 0.6 ml/100g/min) to low intensity exercise (4.1 ± 1...

Nasal mucosal blood flow after intranasal allergen challenge

International Nuclear Information System (INIS)

Holmberg, K.; Bake, B.; Pipkorn, U.

1988-01-01

The nasal mucosal blood flow in patients with allergic rhinitis was determined at nasal allergen challenges with the 133 Xenon washout method. Determinations were made in 12 subjects before and 15 minutes after challenge with diluent and increasing doses of allergen. The time course was followed in eight subjects by means of repeated measurements during 1 hour after a single allergen dose. Finally, the blood flow was measured after unilateral allergen challenge in the contralateral nasal cavity. A dose-dependent decrease in blood flow was found after nasal challenge with increasing doses of allergens, whereas challenge with diluent alone did not induce any changes. The highest allergen dose, which also induced pronounced nasal symptoms, resulted in a decrease in blood flow of 25% (p less than 0.001). The time-course study demonstrated a maximum decrease in blood flow 10 to 20 minutes after challenge and then a gradual return to baseline. Unilateral allergen challenge resulted in a decrease in blood flow in the contralateral, unchallenged nasal cavity, suggesting that part of the allergen-induced changes in blood flow were reflex mediated