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Sample records for cerebral perfusion pressure

  1. Efficacy evaluation of cerebral perfusion pressure in complex treatment of eclamptic coma

    OpenAIRE

    Podolsky Yu.S.; Hapy I.H.

    2010-01-01

    The aim of this research is to study influence of cerebral perfusion pressure on the effectiveness of treatment of maternity patient in eclamptic coma. Fluctuation of average arterial pressure defines dynamics of the cerebral perfusion pressure. Active hypotensive therapy leads to reduction of cerebral blood flow, breaking perfusion balance of brain. The principal objective of treatment in eclamptic coma is to restore volemic indices by using stabizol, decrease of average arterial pressure (1...

  2. Early Cerebral Perfusion Pressure Augmentation with Phenylephrine after Traumatic Brain Injury may be Neuroprotective in a Pediatric Swine Model

    OpenAIRE

    Friess, Stuart H.; Smith, Colin; Kilbaugh, Todd J.; Frangos, Suzanne G; Ralston, Jill; Helfaer, Mark A.; Margulies, Susan S.

    2012-01-01

    : Cerebral perfusion pressure 70, we hypothesize that targeting a cerebral perfusion pressure of 70 mm Hg with the use of phenylephrine early after injury in the immature brain will be neuroprotective.

  3. Preliminary experience of the estimation of cerebral perfusion pressure using transcranial Doppler ultrasonography

    OpenAIRE

    E. Schmidt; Czosnyka, M; Gooskens, I; Piechnik, S; Matta, B.; Whitfield, P; Pickard, J

    2001-01-01

    OBJECTIVE—The direct calculation of cerebral perfusion pressure (CPP) as the difference between mean arterial pressure and intracranial pressure (ICP) produces a number which does not always adequately describe conditions for brain perfusion. A non-invasive method of CPP measurement has previously been reported based on waveform analysis of blood flow velocity measured in the middle cerebral artery (MCA) by transcranial Doppler. This study describes the results of clinica...

  4. Continuous determination of optimal cerebral perfusion pressure in traumatic brain injury

    NARCIS (Netherlands)

    Aries, M.J.H.; Czosnyka, Marek; Budohoski, Karol P.; Steiner, Luzius A.; Lavinio, Andrea; Kolias, Angelos G.; Hutchinson, Peter J.; Brady, Ken M.; Menon, David K.; Pickard, John D.; Smielewski, Peter

    2012-01-01

    Objectives: We have sought to develop an automated methodology for the continuous updating of optimal cerebral perfusion pressure (CPPopt) for patients after severe traumatic head injury, using continuous monitoring of cerebrovascular pressure reactivity. We then validated the CPPopt algorithm by de

  5. Cerebral perfusion pressure management of severe diffuse head injury: Effect on brain compliance and intracranial pressure

    Directory of Open Access Journals (Sweden)

    Pillai S

    2004-01-01

    Full Text Available Background: Cerebral perfusion pressure management (CPPM is an accepted modality of treatment of severe diffuse head injury (SDHI. However, CPPM has the potential to cause transcapillary exudation in the presence of a disrupted blood brain barrier and can lead to further increase of intracranial pressure (ICP and worsening of compliance. Aims: This study attempts to evaluate the effect of both transient and prolonged changes in cerebral perfusion pressure (CPP on ICP and cerebral compliance as measured by the Pressure Volume Index (PVI, and to correlate changes in PVI with outcome at 12 months using the Glasgow Outcome Score. Settings and Design: Prospective study in a neurosurgical ICU. Material and Methods: Twenty-seven SDHI patients managed using standard protocol to maintain CPP above 70 mmHg. Mean arterial pressure (MAP, ICP and CPP were monitored every half-hour. Daily monitoring of the PVI and ICP was done before, and after the induced elevation of MAP using IV Dopamine infusion. The relationship between CPP, MAP, ICP, PVI and outcome was evaluated. Statistical analysis used: The paired and independent samples T-test, and the Pearson correlation coefficient. Results: CPPM rarely leads to progressive rise in ICP. Maintaining CPP above 70mmHg does not influence ICP or PVI. Transient elevations in CPP above 70mmHg may produce a small rise in ICP. Trend of change in PVI influenced outcome despite similar ICP and CPP. Conclusion: Elevating the CPP above 70mmHg does not either reduce the ICP or worsen the compliance. Monitoring changes in compliance should form an integral part of CPPM.

  6. Middle cerebral artery occlusion in presence of low perfusion pressure increases infarct size in rats

    DEFF Research Database (Denmark)

    Sillesen, H; Nedergaard, Majken; Schroeder, T;

    1988-01-01

    A model was set up in order to evaluate the importance of hemispheric perfusion pressure when the middle cerebral artery (MCA) is occluded in anaesthetized rats. In 6 animals the internal carotid artery (ICA) was occluded prior to ipsilateral MCA occlusion; in 17 animals the MCA only was occluded......; 6 animals underwent the same preparation, but the vessels were left unoccluded. Four days after surgery the infarct volume was measured with a computerized image analyser. The infarcted areas were significantly larger in the ICA + MCA occluded group compared with the MCA occluded group (p less than...... occurs, as compared to patients with no, or only minor, reduction in hemispheric perfusion pressure....

  7. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H;

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2 the......This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon...... contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...

  8. Mean transit time as an index of cerebral perfusion pressure in experimental systemic hypotension

    International Nuclear Information System (INIS)

    Early diagnosis of cerebrovascular disease requires the accurate identification of brain regions with compromised cerebral perfusion pressure (CPP). Current clinical measures of CPP are invasive and lack regional information. Dynamic contrast-enhanced imaging provides a means of looking at regional cerebral hemodynamics. The purpose of this study was to determine if any of the parameters associated with dynamic contrast-enhanced imaging could be used as an index for CPP under graded systemic hypotension in a rabbit model. Cerebral blood flow (CBF), cerebral blood volume, mean transit time (MTT), and cerebrovascular reserve (CVR) were measured using Computed Tomography Perfusion in three groups: normotensive (n = 14), mild hypotensive (n = 9), and moderate hypotensive (n = 6). MTT demonstrated the strongest correlation with CPP (ρ = −0.642, P < 0.05). CBF was the only other parameter to demonstrate a statistically significant correlation (ρ = 0.575, P < 0.05). CVR is gaining momentum for diagnosing cerebrovascular disease; however, the technique requires patients to be given a hemodynamic challenge, which could aggravate symptoms and even trigger stroke. The results of this study suggest that the use of MTT, not requiring hemodynamic manipulation, is more sensitive to subtle changes in CPP, as would occur in the early stages of cerebrovascular disease

  9. Postural influence on intracranial and cerebral perfusion pressure in ambulatory neurosurgical patients

    DEFF Research Database (Denmark)

    Petersen, Lonnie Grove; Petersen, Johan Casper Grove; Andresen, Morten;

    2016-01-01

    We evaluated postural effects on intracranial pressure (ICP) and cerebral perfusion pressure (CPP: mean arterial pressure (MAP) - ICP) in neurosurgical patients undergoing 24-hour ICP monitoring as part of their diagnostic workup. We identified 9 patients (5 women, age 44±20 yrs.; mean±SD) who were.......4±4.2 mmHg when standing up (P<0.05). Concordant changes in MAP maintained CPP at 77±7 mmHg regardless of body position (P=0.95). During head-down tilt, the increase in ICP corresponded to a hydrostatic pressure gradient with reference just below the heart, likely reflecting the venous hydrostatic...... veins may protect the brain from being exposed to a large negative pressure when upright. Despite positional changes in ICP, MAP keeps CPP tightly regulated....

  10. Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery

    DEFF Research Database (Denmark)

    Vedel, Anne G; Holmgaard, Frederik; Rasmussen, Lars Simon;

    2016-01-01

    coronary vessel and/or valve disease and who are undergoing cardiac surgery with the use of cardiopulmonary bypass. Patients are stratified by age and surgical procedure and are randomised 1:1 to either an increased mean arterial pressure (70-80 mmHg) or 'usual practice' (40-50 mmHg) during cardiopulmonary...... caused by emboli, but inadequate blood flow caused by other mechanisms may increase ischaemia in the penumbra or cause watershed infarcts. During cardiopulmonary bypass, blood pressure can be below the lower limit of cerebral autoregulation. Although much debated, the constant blood flow provided by the...... cardiopulmonary bypass system is still considered by many as appropriate to avoid cerebral ischaemia despite the low blood pressure. METHODS/DESIGN: The Perfusion Pressure Cerebral Infarct trial is a single-centre superiority trial with a blinded outcome assessment. The trial is randomising 210 patients with...

  11. Cerebral hemodynamics in aging : the interplay between blood pressure, cerebral perfusion, and dementia

    OpenAIRE

    Claassen, J.A.H.R.

    2008-01-01

    Advances in measurement techniques have made it possible to study dynamic changes in brain blood flow. Transcranial Doppler ultrasonography measures changes in cerebral blood flow-velocity in the larger cerebral arteries (e.g. the middle cerebral artery). Near infrared spectroscopy records changes in brain cortical tissue concentrations of hemoglobin. These techniques are non-invasive, and can be performed with the subject in supine, sitting or standing position. Together with photoplethysmog...

  12. Outcome, Pressure Reactivity and Optimal Cerebral Perfusion Pressure Calculation in Traumatic Brain Injury: A Comparison of Two Variants.

    Science.gov (United States)

    Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Santos, Edgar; Pickard, John; Czosnyka, Marek

    2016-01-01

    This study investigates the outcome prediction and calculation of optimal cerebral perfusion pressure (CPPopt) in 307 patients after severe traumatic brain injury (TBI) based on cerebrovascular reactivity calculation of a moving correlation correlation coefficient, named PRx, between mean arterial pressure (ABP) and intracranial pressure (ICP). The correlation coefficient was calculated from simultaneously recorded data using different frequencies. PRx was calculated from oscillations between 0.008 and 0.05Hz and the longPRx (L-PRx) was calculated from oscillations between 0.0008 and 0.016 Hz. PRx was a significant mortality predictor, whereas L-PRx was not. CPPopt for pooled data was higher for L-PRx than for PRx, with no statistical difference. Mortality was associated with mean CPP below CPPopt. Severe disability was associated with CPP above CPPopt (PRx). These relationships were not statistically significant for CPPopt (L-PRx). We conclude that PRx and L-PRx cannot be used interchangeably. PMID:27165910

  13. Perfusion MRI in cerebral infarction

    International Nuclear Information System (INIS)

    Purpose: To investigate the hemodynamic changes in patients with acute cerebral stroke by perfusion MRI. Materials and methods: In 12 patients with acute stroke in the territory of the middle cerebral artery, perfusion MRI was performed. Peak time, mean transit time, regional cerebral blood volume and regional cerebral blood flow were calculated in the infarction, the peri-infarction area and the contralateral hemisphere. Results: In the infarction the mean blood flow was 29 ml/100 g/min, compared to about 40 ml/100 g/min in the peri-infarction area and the contralateral hemisphere. In two patients increased cortical blood flow was found in the infarction due to luxury perfusion. The cerebral blood volume was reduced in the infarction, but significantly increased, to 7.3 ml/100 g, in the peri-infarction tissue. Conclusion: Perfusion MRI allows one to differentiate various patterns of perfusion disorders in patients with acute cerebral stroke. (orig./AJ)

  14. The Effect of Equal Ratio Ventilation on Oxygenation, Respiratory Mechanics, and Cerebral Perfusion Pressure During Laparoscopy in the Trendelenburg Position.

    Science.gov (United States)

    Jo, Youn Yi; Kim, Ji Young; Chang, Young Jin; Lee, Sehwan; Kwak, Hyun Jeong

    2016-06-01

    The aim of this study was to investigate the effects of equal ratio ventilation (ERV) on oxygenation, respiratory mechanics, and the cerebral perfusion pressure during pneumoperitoneum in the Trendelenburg position. Thirty patients undergoing laparoscopic low anterior resection (25 to 65 y) were enrolled. Mechanical ventilator was set to volume-controlled mode at an inspiratory to expiratory (I:E) ratio of 1:2 with a tidal volume of 8 mL/kg of ideal body weight with a 5 cm H2O positive end-expiratory pressure. Twenty minutes after pneumoperitoneum in the Trendelenburg position, the I:E ratio was changed to 1:1 for 20 minutes and then restored to 1:2. No significant changes in arterial oxygen tension and respiratory compliance after adopting ERV. Mean arterial pressure and cerebral perfusion pressure decreased significantly over time after adopting the Trendelenburg position during pneumoperitoneum (P=0.014 and 0.005, respectively). In conclusion, there was no improvement in oxygenation or respiratory mechanics with ERV. PMID:27258912

  15. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

  16. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, Kyung Han; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1996-03-15

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  17. Efeitos da fisioterapia respiratória na pressão intracraniana e pressão de perfusão cerebral no traumatismo cranioencefálico grave Effects of respiratory physiotherapy on intracranial pressure and cerebral perfusion pressure in severe traumatic brain injury patients

    Directory of Open Access Journals (Sweden)

    Cassia Toledo

    2008-12-01

    Full Text Available OBJETIVOS: Após um traumatismo cranioencefálico, a hipertensão intracraniana representa a maior causa de mortalidade, além da possibilidade de seqüelas funcionais, comportamentais e cognitivas. A escassez de estudos sobre os efeitos da fisioterapia respiratória nestes pacientes pode levar à condutas contraditórias. O objetivo deste estudo foi avaliar os efeitos de manobras usuais de fisioterapia respiratória sobre a pressão intracraniana e a pressão de perfusão cerebral em pacientes com traumatismo cranioencefálico grave. MÉTODOS: Ensaio clínico, prospectivo, em pacientes com traumatismo cranioencefálico, ventilados mecanicamente e com medida contínua da pressão intracraniana. Foram avaliados os efeitos das manobras de vibrocompressão manual e aspiração intratraqueal sem e com instilação de soro fisiológico, sobre as medidas de pressão intracraniana e de pressão de perfusão cerebral, entre o primeiro e o terceiro dia após a lesão cerebral. RESULTADOS: Foram obtidos os dados de 11 pacientes com idade de 41anos (mediana APACHE II de 19,5 ± 5. A manobra de vibrocompressão manual não determinou aumento da pressão intracraniana em nenhum dos dias avaliados. A pressão intracraniana aumentou significativamente após manobras de aspiração intratraqueal em relação à medida basal (dia 1, 9,5 ± 0,9 mm Hg vs 18,0 ± 3,2 mm Hg; dia 2, 10,6 ± 1,7 mm Hg vs 21,4 ± 3,8 mm Hg; dia 3, 14,4 ± 1,0 vs 24,9 ± 2,7 mm Hg; pOBJECTIVE: After brain injury intracranial hypertension is the major cause of mortality, in addition to the possibility of functional, behavioral and cognitive sequels. Scarcity of studies on the effects of respiratory physiotherapy on these patients may lead to contradictory performances. This study aimed to assess the effects of customary respiratory physiotherapy maneuvers on intracranial and cerebral perfusion pressures in patients with severe brain injury. METHODS: Clinical, prospective trial with

  18. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    International Nuclear Information System (INIS)

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  19. Transient influence of end-tidal carbon dioxide tension on the postural restraint in cerebral perfusion

    DEFF Research Database (Denmark)

    Immink, R.V.; Truijen, J.; Secher, Niels H.;

    2009-01-01

    In the upright position, cerebral blood flow is reduced, maybe because arterial carbon dioxide partial pressure (Pa(CO(2))) decreases. We evaluated the time-dependent influence of a reduction in Pa(CO(2)), as indicated by the end-tidal Pco(2) tension (Pet(CO(2))), on cerebral perfusion during head...

  20. Acute volume expansion attenuates hyperthermia-induced reductions in cerebral perfusion during simulated hemorrhage

    DEFF Research Database (Denmark)

    Schlader, Zachary J; Seifert, Thomas; Wilson, Thad E; Bundgaard-Nielsen, Morten; Secher, Niels H; Crandall, Craig G

    2013-01-01

    infusion while hyperthermic. Primary dependent variables were mean middle cerebral artery blood velocity (MCAvmean), serving as an index of cerebral perfusion; mean arterial pressure (MAP); and cardiac output (thermodilution). During baseline, hyperthermia reduced MCAvmean (P = 0.001) by 12 ± 9% relative...

  1. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Fisher, James P; Young, Colin N; Hartwich, Doreen; Ogoh, Shigehiko; Raven, Peter B; Fadel, Paul J; Secher, Niels H

    2010-01-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebral......) (P <0.01) and cardiac output by approximately 40% (P <0.05), but did not affect mean arterial pressure. The central cardiovascular responses to exercise with glycopyrrolate were similar to the control responses, except that cardiac output did not increase during static handgrip with glycopyrrolate...... abolished by glycopyrrolate (P <0.05). Thus, during both cycling and static handgrip, a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen....

  2. Cerebral perfusion imaging using contrast-enhanced MRI

    International Nuclear Information System (INIS)

    New developments in fast magnetic resonance imaging (MRI) have enabled imaging of cerebral haemodynamics. This article describes the theory behind perfusion imaging and provides an overview of the most commonly used MRI technique. Limitations of this technique are described, and the potential clinical applications are discussed, with particular attention to the role of perfusion imaging in the context of stroke and brain tumour

  3. Cerebral perfusion deficits in divers with neurological decompression illness

    International Nuclear Information System (INIS)

    Cerebral perfusion deficits detected by injection of 99Tcm-hexamethylpropyleneamine oxime (HMPAO) and single photon emission tomography is said to correlate well with clinical findings in divers with neurological decompression illness. We studied 12 divers. Six had residual cerebral signs (group 1) and six had no residual cerebral symptoms or signs (group 2). Perfusion deficits were as common in group 2 as in group 1. The site of the deficit did not correlate well with either the neurological findings at presentation or the residual clinical signs after treatment. The data suggest that claims that HMPAO scanning correlates with clinical findings and can be used for patient management were incorrect. (author)

  4. How to Perfuse: Concepts of Cerebral Protection during Arch Replacement

    Directory of Open Access Journals (Sweden)

    Andreas Habertheuer

    2015-01-01

    Full Text Available Arch surgery remains undoubtedly among the most technically and strategically challenging endeavors in cardiovascular surgery. Surgical interventions of thoracic aneurysms involving the aortic arch require complete circulatory arrest in deep hypothermia (DHCA or elaborate cerebral perfusion strategies with varying degrees of hypothermia to achieve satisfactory protection of the brain from ischemic insults, that is, unilateral/bilateral antegrade cerebral perfusion (ACP and retrograde cerebral perfusion (RCP. Despite sophisticated and increasingly individualized surgical approaches for complex aortic pathologies, there remains a lack of consensus regarding the optimal method of cerebral protection and circulatory management during the time of arch exclusion. Many recent studies argue in favor of ACP with various degrees of hypothermic arrest during arch reconstruction and its advantages have been widely demonstrated. In fact ACP with more moderate degrees of hypothermia represents a paradigm shift in the cardiac surgery community and is widely adopted as an emergent strategy; however, many centers continue to report good results using other perfusion strategies. Amidst this important discussion we review currently available surgical strategies of cerebral protection management and compare the results of recent European multicenter and single-center data.

  5. Diffusion and Perfusion MRI in Acute Cerebral Ischemia

    Institute of Scientific and Technical Information of China (English)

    Tchoyoson CC Lim; Chong-Tin Tan

    2001-01-01

    Reeent advances in magnetic resonance imaging (MRI), in particular diffusion weighted imaging (DWI) and perfusion weighted imaging (PWI), have allowed clinicians to have the ability to differentiate between irreversible cerebral infarction and the potentially reversible ischemic penumbra. This article examines the principles and practice of DWI and PWI. With continued advances in thrombolysis and other therapy for acute cerebral ischemia, neuroimaging is poised to play an increasingly important role in decisionmaking in aeute stroke.

  6. Cerebral perfusion, oxygenation and metabolism during exercise in young and elderly individuals

    DEFF Research Database (Denmark)

    Fisher, James P; Hartwich, Doreen; Seifert, Thomas;

    2013-01-01

    artery blood velocity (MCA V(mean)), mean arterial pressure (MAP), cardiac output (CO) and the partial pressure of arterial carbon dioxide (PaCO(2)) were measured. Blood samples were obtained from the right internal jugular vein and brachial artery to determine concentration differences for oxygen (O(2......We evaluated cerebral perfusion, oxygenation, and metabolism in eleven young (age 22 ± 1 years) and nine older (age 66 ± 2 years) individuals at rest and during cycling exercise at low (25% W(max)), moderate (50% W(max)), high (75% W(ma)) and exhaustive (100% W(max)) workloads. Mean middle cerebral...

  7. The usefulness of deconvolution perfusion CT in patients with acute cerebral infarction: comparison with diffusion MRI

    International Nuclear Information System (INIS)

    This study was performed to evaluate the usefulness of Deconvolution perfusion CT in patients with acute cerebral infarction. Nine patients with acute cerebral infarction underwent conventional CT and cerebral perfusion CT within 23 hours of the onset of symptoms. The perfusion CT scan for each patient was obtained at the levels of basal ganglia and 1 cm caudal to the basal ganglia. By special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were created. The infarcted lesions were evaluated on each perfusion maps by 3 radiolocical technician. MTT delay time was measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Lesion size were measured on each perfusion map and compared with the value obtained by diffusion weighted MR imaging (DWMRI). All perfusion CT maps showed the perfusion defect lesion in all patients. There were remarkable MTT delay in perfusion defect lesion. In comparison of lesion size between each perfusion map and DWMRI, the lesion on CBF map was the most closely correlated with the lesion on DWMRI (7/9). The size of perfusion defect lesion on MTT map was larger than that of lesion on DWMRI, suggesting that MTT map can evaluate the ischemic penumbra. Deconvolution Perfusion CT maps make it possible to evaluate not only ischemic core and ischemic penumbra but also hemodynamic status in perfusion defect area. These results demonstrate that perfusion CT can be useful to the diagnosis and treatment in the patients with acute cerebral ischemic infarction

  8. The usefulness of deconvolution perfusion CT in patients with acute cerebral infarction: comparison with diffusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Sung Jong [Chonnam National University Graduate School, Gwangju (Korea, Republic of); Kim, Young Keun [Kwangju Health College, Gwangju (Korea, Republic of)

    2003-06-15

    This study was performed to evaluate the usefulness of Deconvolution perfusion CT in patients with acute cerebral infarction. Nine patients with acute cerebral infarction underwent conventional CT and cerebral perfusion CT within 23 hours of the onset of symptoms. The perfusion CT scan for each patient was obtained at the levels of basal ganglia and 1 cm caudal to the basal ganglia. By special imaging software, perfusion images including cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps were created. The infarcted lesions were evaluated on each perfusion maps by 3 radiolocical technician. MTT delay time was measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Lesion size were measured on each perfusion map and compared with the value obtained by diffusion weighted MR imaging (DWMRI). All perfusion CT maps showed the perfusion defect lesion in all patients. There were remarkable MTT delay in perfusion defect lesion. In comparison of lesion size between each perfusion map and DWMRI, the lesion on CBF map was the most closely correlated with the lesion on DWMRI (7/9). The size of perfusion defect lesion on MTT map was larger than that of lesion on DWMRI, suggesting that MTT map can evaluate the ischemic penumbra. Deconvolution Perfusion CT maps make it possible to evaluate not only ischemic core and ischemic penumbra but also hemodynamic status in perfusion defect area. These results demonstrate that perfusion CT can be useful to the diagnosis and treatment in the patients with acute cerebral ischemic infarction.

  9. Glycopyrrolate abolishes the exercise-induced increase in cerebral perfusion in humans

    DEFF Research Database (Denmark)

    Seifert, Thomas; Fisher, James P; Young, Colin N;

    2010-01-01

    Brain blood vessels contain muscarinic receptors that are important for cerebral blood flow (CBF) regulation, but whether a cholinergic receptor mechanism is involved in the exercise-induced increase in cerebral perfusion or affects cerebral metabolism remains unknown. We evaluated CBF and cerebr...... abolished by glycopyrrolate (P <0.05). Thus, during both cycling and static handgrip, a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen....

  10. Personal computer aided cerebral perfusion imaging with dynamic CT

    Institute of Scientific and Technical Information of China (English)

    林燕; 高培毅

    2004-01-01

    @@Reports on the clinical implementation of dynamic computerised tomography (CT) perfusion imaging and quantitative measurement have increased dramatically of late.1-8 The advantages of dynamic CT perfusion imaging and quantitative measurement for the diagnosis of acute cerebral infarction have been acknowledged. However, most overseas CT vendors set perfusion imaging software package as an option for graphic workstation at a too high price for domestic practitioners. To foster the domestic implementation and development of this new technology, we have extended the earlier work.1,2 Applying the theory of central volume principle to DICOM 3.0 standard forms of prime CT images, we developed dynamic CT perfusion imaging and quantitative measure-ment programmes for PCs using Visual C+ + in Windows 98 system.

  11. Noninvasive cerebral perfusion imaging in high-risk neonates.

    Science.gov (United States)

    Goff, Donna A; Buckley, Erin M; Durduran, Turgut; Wang, Jiongjong; Licht, Daniel J

    2010-02-01

    Advances in medical and surgical care of the high-risk neonate have led to increased survival. A significant number of these neonates suffer from neurodevelopmental delays and failure in school. The focus of clinical research has shifted to understanding events contributing to neurological morbidity in these patients. Assessing changes in cerebral oxygenation and regulation of cerebral blood flow (CBF) is important in evaluating the status of the central nervous system. Traditional CBF imaging methods fail for both ethical and logistical reasons. Optical near infrared spectroscopy (NIRS) is increasingly being used for bedside monitoring of cerebral oxygenation and blood volume in both very low birth weight infants and neonates with congenital heart disease. Although trends in CBF may be inferred from changes in cerebral oxygenation and/or blood volume, NIRS does not allow a direct measure of CBF in these populations. Two relatively new modalities, arterial spin-labeled perfusion magnetic resonance imaging and optical diffuse correlation spectroscopy, provide direct, noninvasive measures of cerebral perfusion suitable for the high-risk neonates. Herein we discuss the instrumentation, applications, and limitations of these noninvasive imaging techniques for measuring and/or monitoring CBF. PMID:20109972

  12. Retrograde Cerebral Perfusion Results in Better Perfusion to the Striatum Than the Cerebral Cortex During Deep Hypothermic Circulatory Arrest: A Microdialysis Study.

    Science.gov (United States)

    Liang, Meng-Ya; Chen, Guang-Xian; Tang, Zhi-Xian; Rong, Jian; Yao, Jian-ping; Wu, Zhong-Kai

    2016-03-01

    It remains controversial whether contemporary cerebral perfusion techniques, utilized during deep hypothermic circulatory arrest (DHCA), establish adequate perfusion to deep structures in the brain. This study aimed to investigate whether selective antegrade cerebral perfusion (SACP) or retrograde cerebral perfusion (RCP) can provide perfusion equally to various anatomical positions in the brain using metabolic evidence obtained from microdialysis. Eighteen piglets were randomly assigned to 40 min of circulatory arrest (CA) at 18°C without cerebral perfusion (DHCA group, n = 6) or with SACP (SACP group, n = 6) or RCP (RCP group, n = 6). Microdialysis parameters (glucose, lactate, pyruvate, and glutamate) were measured every 30 min in cortex and striatum. After 3 h of reperfusion, brain tissue was harvested for Western blot measurement of α-spectrin. After 40 min of CA, the DHCA group showed marked elevations of lactate and glycerol and a reduction in glucose in the microdialysis perfusate (all P spectrin expression in brain tissue were similar between cortex and striatum in the SACP group (all P > 0.05). In the RCP group, the cortex exhibited lower glucose, higher lactate, and higher glycerol in the perfusate and higher α-spectrin expression in brain tissue compared with the striatum (all P 0.05). In summary, SACP provided uniform and continuous cerebral perfusion to most anatomical sites in the brain, whereas RCP resulted in less sufficient perfusion to the cortex but better perfusion to the striatum. PMID:26333187

  13. SPECT evaluation of cerebral perfusion reserve in patients with occlusive cerebrovascular disease. Evaluation with acetazolamide test and crossed cerebellar diaschisis

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Yoshifumi [Ehime Univ., Shigenobu (Japan). School of Medicine

    1995-03-01

    In 53 patients with chronic occlusive cerebrovascular diseases, we evaluated cerebral perfusion reserve. Cerebral perfusion reserve was evaluated by the change in cerebral blood flow (CBF) at rest and the CBF after acetazolamide (Diamox) as measured by the {sup 133}Xe gas inhalation SPECT method. Crossed cerebellar diaschisis (CCD) was evaluated semiquantitatively by the count ratio of the cerebellar cortex using {sup 99m}Tc-HMPAO SPECT. Thirty-two (49%) of the 65 affected lesions in 53 patients had shown a decreased response to Diamox. In the cases of decreased response to Diamox, the response improved significantly after surgery. However, CBF did not improve as much as the response. In the 40 nonaffected sides, 21 (53%) showed decreased CBF at rest but good response to Diamox. At rest, no difference of the CBF ratio (affected/contralateral nonaffected cerebral cortex) was observed between the patients with CCD (6 pts) and those without CCD (8 pts). After Diamox, however, the CBF ratio of the patients with CCD was significantly higher than that without CCD. The change of the CBF ratio before and after Diamox correlated significantly with the degree of CCD (r=-0.794, p<0.01). Diamox was useful for evaluating the cerebral perfusion reserve to indicate surgery in patients with chronic cerebrovascular diseases. Perhaps CCD could be a useful index in the differentiation of the decreased CBF caused by reduced perfusion pressure from that caused by reduced metabolic demand because CCD had a close relationship with the cerebral perfusion reserve. (author).

  14. Evaluation of ocular acupuncture on cerebral infarction with cerebral blood flow perfusion imaging

    International Nuclear Information System (INIS)

    To evaluate the immediate effect of ocular acupuncture on patients, an method of SPECT image of cerebral blood flow daily stress test was established. 10 patients diagnosed as cerebral infarction by CT or MRI were tested. They all received 99Tcm-ECD SPECT imaging at twice before and after ocular acupuncture. By means of image subtraction technique and semi-quantitative method of regional interesting area, the change of regional cerebral blood flow was observed between the two images. Under restful state perfusion of cerebral blood flow in 18 foci was low at the frontal lobe, the cerebellum, the basal ganglia and temporal lobe. After ocular acupuncture, the perfusions were obviously increased in 16 foci among them and the reactivity of the frontal lobe and the cerebellum to ocular acupuncture was higher, the average improvement rate of which was 55.15% and 53.06% respectively, lower in the basal ganglia and temporal lobe, the average improvement rate was 31.79% and 36.67% respectively. 99Tcm-ECD SPECT cerebral perfusion image has some significant clinic value for evaluating the effect of ocular acupuncture to treating cerebral infarction. (authors)

  15. The effects of propofol on cerebral perfusion MRI in children

    International Nuclear Information System (INIS)

    The effects of anesthesia are infrequently considered when interpreting pediatric perfusion magnetic resonance imaging (MRI). The objectives of this study were to test for measurable differences in MR measures of cerebral blood flow (CBF) and cerebral blood volume (CBV) between non-sedated and propofol-sedated children, and to identify influential factors. Supratentorial cortical CBF and CBV measured by dynamic susceptibility contrast perfusion MRI in 37 children (1.8-18 years) treated for infratentorial brain tumors receiving propofol (IV, n = 19) or no sedation (NS, n = 18) were compared between groups and correlated with age, hematocrit (Hct), end-tidal CO2 (ETCO2), dose, weight, and history of radiation therapy (RT). The model most predictive of CBF and CBV was identified by multiple linear regression. Anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory CBF were significantly lower, and MCA territory CBV greater (p = 0.03), in IV than NS patients (p = 0.01, 0.04). The usual trend of decreasing CBF with age was reversed with propofol in ACA and MCA territories (r = 0.53, r = 0.47; p 2, hematocrit, or RT. In propofol-sedated children, usual age-related decreases in CBF were reversed, and increases in CBF and CBV were weight-dependent, not previously described. Weight-dependent increases in propofol clearance may diminish suppression of CBF and CBV. Prospective study is required to establish anesthetic-specific models of CBF and CBV in children. (orig.)

  16. The effects of propofol on cerebral perfusion MRI in children

    Energy Technology Data Exchange (ETDEWEB)

    Harreld, Julie H.; Helton, Kathleen J.; Reddick, Wilburn E.; Glass, John O.; Sansgiri, Rakhee; Ji, Qing; Patay, Zoltan [St. Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); Kaddoum, Roland N.; Parish, Mary Edna [St. Jude Children' s Research Hospital, Department of Anesthesiology, Memphis, TN (United States); Li, Yimei; Feng, Tianshu [St. Jude Children' s Research Hospital, Department of Biostatistics, Memphis, TN (United States); Gajjar, Amar [St. Jude Children' s Research Hospital, Department of Oncology, Memphis, TN (United States)

    2013-08-15

    The effects of anesthesia are infrequently considered when interpreting pediatric perfusion magnetic resonance imaging (MRI). The objectives of this study were to test for measurable differences in MR measures of cerebral blood flow (CBF) and cerebral blood volume (CBV) between non-sedated and propofol-sedated children, and to identify influential factors. Supratentorial cortical CBF and CBV measured by dynamic susceptibility contrast perfusion MRI in 37 children (1.8-18 years) treated for infratentorial brain tumors receiving propofol (IV, n = 19) or no sedation (NS, n = 18) were compared between groups and correlated with age, hematocrit (Hct), end-tidal CO{sub 2} (ETCO{sub 2}), dose, weight, and history of radiation therapy (RT). The model most predictive of CBF and CBV was identified by multiple linear regression. Anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory CBF were significantly lower, and MCA territory CBV greater (p = 0.03), in IV than NS patients (p = 0.01, 0.04). The usual trend of decreasing CBF with age was reversed with propofol in ACA and MCA territories (r = 0.53, r = 0.47; p < 0.05). ACA and MCA CBF (r = 0.59, 0.49; p < 0.05) and CBV in ACA, MCA, and posterior cerebral artery territories (r = 0.73, 0.80, 0.52; p < 0.05) increased with weight in propofol-sedated children, with no significant additional influence from age, ETCO{sub 2}, hematocrit, or RT. In propofol-sedated children, usual age-related decreases in CBF were reversed, and increases in CBF and CBV were weight-dependent, not previously described. Weight-dependent increases in propofol clearance may diminish suppression of CBF and CBV. Prospective study is required to establish anesthetic-specific models of CBF and CBV in children. (orig.)

  17. Cerebral perfusion reserve indexes determined by fluoromethane positron emission scanning

    International Nuclear Information System (INIS)

    An index of cerebral perfusion reserve (RES%), defined as the percent change of regional cerebral blood flow over baseline per mm Hg of end-tidal CO2 tension, was determined for each middle cerebral artery (MCA) territory in patients with unilateral carotid distribution transient ischemic attacks or minor cerebrovascular accidents and was compared with that of age-matched, neurologically normal volunteers. Vasodilator responses to induced hypercapnia were tested during inhalation of 5% CO2 in 95% O2 while regional cerebral blood flow was measured by fluoromethane inhalation positron emission tomography. Mean RES% for 24 normal MCA territories was 5.2 +/- 0.8%. Mean RES% for 15 patient nonischemic MCA territories was 3.8 +/- 1.3% and for 15 ischemic MCA territories was 2.8 +/- 1.9% (both p less than 0.001). Individual RES% values and symmetry ratios between ischemic and nonischemic regions were also determined and compared with angiographic data. Areas of diminished, asymmetric, or paradoxical (two patients) CO2 reactivity appear to correspond to areas of compensatory vasodilation. We found this technique to be a safe and reproducible method for defining and recording localized areas of cerebral tissue at apparent risk for hemodynamically related damage

  18. Prognostic indices for cerebral venous thrombosis on CT perfusion: A prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rakesh Kumar, E-mail: rakrakgupta@gmail.com [Department of Radiodiagnosis and Imaging, MMIMSR, Mullana, Ambala (India); Bapuraj, J.R., E-mail: jrajiv@med.umich.edu [Department of Radiology, Division of Neuroradiology, University Hospital, University of Michigan, 1500 E Medical Center Drive, Ann Arbor, MI 48109 (United States); Khandelwal, N. [Department of Radiodiagnosis and Imaging, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh (India); Khurana, Dheeraj [Department of Neurology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh (India)

    2014-01-15

    Purpose: We determined the prognostic significance of CT perfusion characteristics of patients with cerebral venous sinus thrombosis (CVST) and assessed the change in perfusion parameters following anticoagulation therapy. Materials and methods: 20 patients with CVST diagnosed on non-contrast computed tomography (NCCT), magnetic resonance imaging (MRI), and magnetic resonance venography (MRV) were included in this study. The initial CT perfusion study was performed at the time of admission. The following perfusion parameters: relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) were calculated in the core and periphery of the affected area of the brain. Follow-up CT perfusion studies were performed at 1 month following anticoagulation therapy and the perfusion parameters thus obtained were compared with pre-treatment results. Receiver operating characteristic (ROC) curve analysis was performed to determine the prognostic significance of perfusion parameters. Results: All patients in this study showed areas of hypoperfusion on CT perfusion. To determine the favorable clinical outcome on basis of perfusion parameters, ROC curve analysis was performed which showed that the optimal threshold for rCBF > 60.5%, rCBV > 75.5%, and rMTT < 148.5% correlated with better clinical outcomes. Post treatment perfusion parameters showed significant correlation in core of the lesion (p < 0.05) than in the periphery. Conclusion: CT perfusion studies in CVST are a good prognostic tool and yield valuable information regarding clinical outcome.

  19. Prognostic indices for cerebral venous thrombosis on CT perfusion: A prospective study

    International Nuclear Information System (INIS)

    Purpose: We determined the prognostic significance of CT perfusion characteristics of patients with cerebral venous sinus thrombosis (CVST) and assessed the change in perfusion parameters following anticoagulation therapy. Materials and methods: 20 patients with CVST diagnosed on non-contrast computed tomography (NCCT), magnetic resonance imaging (MRI), and magnetic resonance venography (MRV) were included in this study. The initial CT perfusion study was performed at the time of admission. The following perfusion parameters: relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and relative mean transit time (rMTT) were calculated in the core and periphery of the affected area of the brain. Follow-up CT perfusion studies were performed at 1 month following anticoagulation therapy and the perfusion parameters thus obtained were compared with pre-treatment results. Receiver operating characteristic (ROC) curve analysis was performed to determine the prognostic significance of perfusion parameters. Results: All patients in this study showed areas of hypoperfusion on CT perfusion. To determine the favorable clinical outcome on basis of perfusion parameters, ROC curve analysis was performed which showed that the optimal threshold for rCBF > 60.5%, rCBV > 75.5%, and rMTT < 148.5% correlated with better clinical outcomes. Post treatment perfusion parameters showed significant correlation in core of the lesion (p < 0.05) than in the periphery. Conclusion: CT perfusion studies in CVST are a good prognostic tool and yield valuable information regarding clinical outcome

  20. Measurement of radiation dose in cerebral CT perfusion study

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate radiation dose in cerebral perfusion studies with a multi-detector row CT (MDCT) scanner on various voltage and current settings by using a human head phantom. Following the CT perfusion study protocol, continuous cine scans (1 sec/rotation x 60 sec) consisting of four 5-mm-thick contiguous slices were performed three times at variable tube voltages of 80 kV, 100 kV, 120 kV, and 140 kV with the same tube current setting of 200 mA and on variable current settings of 50 mA, 100 mA, 150 mA, and 200 mA with the same tube voltage of 80 kV. Radiation doses were measured using a total of 41 thermoluminescent dosimeters (TLDs) placed in the human head phantom. Thirty-six TLDs were inside and three were on the surface of the slice of the X-ray beam center, and two were placed on the surface 3 cm caudal assuming the lens position. Average radiation doses of surface, inside, and lens increased in proportion to the increases of tube voltage and tube current. The lowest inside dose was 87.6±15.3 mGy, and the lowest surface dose was 162.5±6.7 mGy at settings of 80 kV and 50 mA. The highest inside dose was 1,591.5±179.7 mGy, and the highest surface dose was 2,264.6±123.7 mGy at 140 kV-200 mA. At 80 kV-50 mA, the average radiation dose of lens was the lowest at 5.5±0.0 mGy. At 140 kV-200 mA the radiation dose of lens was the highest at 127.2±0.6 mGy. In cerebral CT perfusion study, radiation dose can vary considerably. Awareness of the patient's radiation dose is recommended. (author)

  1. Endotoxemia reduces cerebral perfusion but enhances dynamic cerebrovascular autoregulation at reduced arterial carbon dioxide tension*

    DEFF Research Database (Denmark)

    Brassard, Patrice; Kim, Yu-Sok; van Lieshout, Johannes;

    2012-01-01

    OBJECTIVE:: The administration of endotoxin to healthy humans reduces cerebral blood flow but its influence on dynamic cerebral autoregulation remains unknown. We considered that a reduction in arterial carbon dioxide tension would attenuate cerebral perfusion and improve dynamic cerebral...... in arterial carbon dioxide tension explains the improved dynamic cerebral autoregulation and the reduced cerebral perfusion encountered in healthy subjects during endotoxemia.......-104] mm Hg; p = .75), but increased cardiac output (8.3 [6.1-9.5] L·min vs. 6.0 [4.5-8.2] L·min; p = .02) through an elevation in heart rate (82 ± 9 beats·min vs. 63 ± 10 beats·min; p <.001), whereas arterial carbon dioxide tension (37 ± 5 mm Hg vs. 41 ± 2 mm Hg; p <.05) and middle cerebral artery mean...

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

    Directory of Open Access Journals (Sweden)

    Chien Hung Chang

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

  3. Imaging findings and cerebral perfusion in arterial ischemic stroke due to transient cerebral arteriopathy in children; Achados de imagem e perfusao arterial cerebral em acidente vascular cerebral isquemico devido a arteriopatia transitoria em crianca

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa Junior, Alcino Alves, E-mail: alcinojr@uol.com.br [Departamento de Diagnostico por Imagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Ellovitch, Saada Resende de Souza [Neuropediatria, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Pincerato, Rita de Cassia Maciel [Hospital Samaritano, Sao Paulo, SP (Brazil)

    2012-04-15

    We report the case of a 4-year-old female child who developed an arterial ischemic stroke in the left middle cerebral artery territory, due to a proximal stenosis of the supraclinoid internal carotid artery, most probably related to transient cerebral arteriopathy of childhood. Computed tomography scan, magnetic resonance imaging, perfusion magnetic resonance and magnetic resonance angiography are presented, as well as follow-up by magnetic resonance and magnetic resonance angiography exams. Changes in cerebral perfusion and diffusion-perfusion mismatch call attention. As far as we know, this is the first report of magnetic resonance perfusion findings in transient cerebral arteriopathy. (author)

  4. Perfusion-CT for early assessment of traumatic cerebral contusions

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    Soustiel, Jean F.; Mahamid, Eugenia; Goldsher, Dorith; Zaaroor, Menashe [Faculty of Medicine, Technion - Israel Institute of Technology, Department of Neurosurgery, Rambam Medical Center, P.O. Box 9602, Haifa (Israel)

    2008-02-15

    To investigate the value of perfusion-CT (PCT) for assessment of traumatic cerebral contusions (TCC) and to compare the abilities of early noncontrast CT and PCT modalities to evaluate tissue viability. PCT studies performed in 30 patients suffering from TCC during the acute phase of their illness were retrospectively reviewed. Cerebral blood flow (CBF), volume (CBV) and mean transit time (MTT) were measured in three different areas: the hemorrhagic core of the TCC, the surrounding hypodense area and the perilesional normal-appearing parenchyma. TCC area was measured on CBF-, CBV- and MTT-derived maps and compared with the areas measured using the same slice obtained with CT scans performed on admission, at the time of PCT (follow-up CT) and at 1 week. TCC were characterized by low CBF and CBV values (9.2{+-}6.6 ml/100 g per min and 0.9{+-}0.7 ml/100 g, respectively) and a significant prolongation of MTT (11.9{+-}10.7 s) in the hemorrhagic core whereas PCT parameters were more variable in the hypodense area. The TCC whole area showed a noticeable growth of the lesions during the first week of admission. In comparison with early noncontrast CT, CBV and CBF maps proved to be more congruent with the findings of noncontrast CT scans at 1 week. PCT confirmed the results of xenon-CT studies and was shown to allow better evaluation of tissue viability than noncontrast CT. These findings suggest that PCT could be implemented in the future for the early assessment of patients with traumatic brain injury. (orig.)

  5. Perfusion-CT for early assessment of traumatic cerebral contusions

    International Nuclear Information System (INIS)

    To investigate the value of perfusion-CT (PCT) for assessment of traumatic cerebral contusions (TCC) and to compare the abilities of early noncontrast CT and PCT modalities to evaluate tissue viability. PCT studies performed in 30 patients suffering from TCC during the acute phase of their illness were retrospectively reviewed. Cerebral blood flow (CBF), volume (CBV) and mean transit time (MTT) were measured in three different areas: the hemorrhagic core of the TCC, the surrounding hypodense area and the perilesional normal-appearing parenchyma. TCC area was measured on CBF-, CBV- and MTT-derived maps and compared with the areas measured using the same slice obtained with CT scans performed on admission, at the time of PCT (follow-up CT) and at 1 week. TCC were characterized by low CBF and CBV values (9.2±6.6 ml/100 g per min and 0.9±0.7 ml/100 g, respectively) and a significant prolongation of MTT (11.9±10.7 s) in the hemorrhagic core whereas PCT parameters were more variable in the hypodense area. The TCC whole area showed a noticeable growth of the lesions during the first week of admission. In comparison with early noncontrast CT, CBV and CBF maps proved to be more congruent with the findings of noncontrast CT scans at 1 week. PCT confirmed the results of xenon-CT studies and was shown to allow better evaluation of tissue viability than noncontrast CT. These findings suggest that PCT could be implemented in the future for the early assessment of patients with traumatic brain injury. (orig.)

  6. Diagnostic value of stress acetazolamide cerebral perfusion SPECT in vertebrobasilar insufficiency

    International Nuclear Information System (INIS)

    Full text: Introduction: Vertebrobasilar insufficiency (VBI) is difficult to diagnose because its symptoms are varied and nonspecific. Brain CT and MRI may be normal until parenchymal damage develops and treatment may be delayed. Clinical history An 82 year-old gentleman presented with several years' history of increasing exertional dizziness and imbalance, on occasion associated with syncope. Brain CT and MRI with angiography demonstrated moderate microvascular changes in the posterior circulation territory without significant vascular pathology in the brainstem. Method: Rest and stress cerebral perfusion imaging using Technetium 99m-labelled HMPAO was performed with SPEeT acquisition on a triple-head gamma-camera with fan-beam collimators. In the stress study, 1 gm of IV acetazolamide was administered 20 minutes before tracer injection. Analysis was performed by mapping the cerebral perfusion scan to a standard brain atlas and comparing this to an age-matched normal database, using the Neurostat program. Results: The resting HMPAO study demonstrated mild perfusion defects in the left temporo-occipital cortex which were more extensive and severe on the stress HMPAO study. In addition, there were stress-induced perfusion defects in the mid-brain. The findings were consistent with reduced cerebral perfusion reserve in the posterior cerebral circulation. Conclusion: The perfusion scan confirmed VBl as the cause of the patient's symptoms and allowed targeted treatment. The literature suggests that cerebral perfusion SPECT detects cerebral ischaemia earlier than anatomic imaging such as MRJ. However there is little data concerning its use in diagnosing VB. Our case report highlights the value of cerebral perfusion SPECT as a sensitive diagnostic modality for VB.

  7. Large cerebral perfusion defects observed in brain perfusion SPECT may herald psychiatric or neurodegenerative diseases of transient global amnesia patients

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    So, Young; Kim, Hahn Young; Roh, Hong Gee; Han, Seol Heui [Konkuk University School of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    Transient global amnesia (TGA) is a memory disorder characterized by an episode of antegrade amnesia and bewilderment which persists for several hours. We analyzed brain perfusion SPECT findings and clinical outcome of patients who suffered from TGA. From September 2005 to August 2007, 12 patients underwent Tc-99m ECD brain perfusion SPECT for neuroimaging of TGA. All patients also underwent MRI and MRA including DWI (MRI). Among them, 10 patients who could be chased more than 6 months were included in this study. Their average age was 60.74.0 yrs (M: F = 2: 8) and the average duration of amnesia was 4.42.2 hrs (1 hr {approx} 7 hrs). Duration from episode of amnesia to SPECT was 4.32.4 days (1{approx}9 days). Precipitating factors could be identified in 6 patients: emotional stress 3, hair dyeing 1, taking a nap 1 and angioplasty 1. SPECT and MRI was visually assessed, No cerebral perfusion defect was observed on SPECT in 3 patients and their clinical outcome was all good. Among 7 patients who had cerebral perfusion defects on SPECT, 3 patients had good clinical outcome, while others did not: one had hypercholesterolemia, another had depression, and 2 patients with cerebral perfusion defects at both temporoparetal cortex was later diagnosed as early Alzheimer's disease (AD) and mild cognitive impairment (MCI). MRI was negative in 6 patients and 3 of them had excellent clinical outcome while other 3 were diagnosed as hypercholesterolemia, early AD and MCI. Among 4 patients with positive MRI, 3 showed good clinical outcome and their MRI showed lesions at medial temporal cortex and/or vertebral artery. One patient with microcalcification at left putamen was diagnosed to have depression. Large cerebral perfusion defects on SPECT may herald psychiatric or neurodegenerative diseases of transient global amnesia patients which usually shows negative MRI.

  8. Large cerebral perfusion defects observed in brain perfusion SPECT may herald psychiatric or neurodegenerative diseases of transient global amnesia patients

    International Nuclear Information System (INIS)

    Transient global amnesia (TGA) is a memory disorder characterized by an episode of antegrade amnesia and bewilderment which persists for several hours. We analyzed brain perfusion SPECT findings and clinical outcome of patients who suffered from TGA. From September 2005 to August 2007, 12 patients underwent Tc-99m ECD brain perfusion SPECT for neuroimaging of TGA. All patients also underwent MRI and MRA including DWI (MRI). Among them, 10 patients who could be chased more than 6 months were included in this study. Their average age was 60.74.0 yrs (M: F = 2: 8) and the average duration of amnesia was 4.42.2 hrs (1 hr ∼ 7 hrs). Duration from episode of amnesia to SPECT was 4.32.4 days (1∼9 days). Precipitating factors could be identified in 6 patients: emotional stress 3, hair dyeing 1, taking a nap 1 and angioplasty 1. SPECT and MRI was visually assessed, No cerebral perfusion defect was observed on SPECT in 3 patients and their clinical outcome was all good. Among 7 patients who had cerebral perfusion defects on SPECT, 3 patients had good clinical outcome, while others did not: one had hypercholesterolemia, another had depression, and 2 patients with cerebral perfusion defects at both temporoparetal cortex was later diagnosed as early Alzheimer's disease (AD) and mild cognitive impairment (MCI). MRI was negative in 6 patients and 3 of them had excellent clinical outcome while other 3 were diagnosed as hypercholesterolemia, early AD and MCI. Among 4 patients with positive MRI, 3 showed good clinical outcome and their MRI showed lesions at medial temporal cortex and/or vertebral artery. One patient with microcalcification at left putamen was diagnosed to have depression. Large cerebral perfusion defects on SPECT may herald psychiatric or neurodegenerative diseases of transient global amnesia patients which usually shows negative MRI

  9. Cerebral perfusion changes in traumatic diffuse brain injury. IMP SPECT studies

    International Nuclear Information System (INIS)

    Diffuse brain injury (DBI) is characterized by axonal degeneration and neuronal damage which cause diffuse brain atrophy. We have investigated the time course of abnormalities in cerebral perfusion distribution in cases of DBI by using Iodine-123-IMP SPECT, and the relationship to the appearance of diffuse brain atrophy. SPECT scans were performed on eight patients with diffuse brain injury due to closed cranial trauma in acute and chronic stages. All patients showed abnormalities in cerebral perfusion with decreases in perfusion, even in non-depicted regions on MRI, and the affected areas varied throughout the period of observation. Diffuse brain atrophy appeared in all patients. In some patients, diffuse brain atrophy was observed at or just after the time when the maximum number of lesions on SPECT were seen. The abnormalities in cerebral perfusion in cases of DBI might therefore be related to axonal degeneration and neuronal damage which causes diffuse brain atrophy. (author)

  10. Cerebral perfusion in cardiac surgery : with special reference to circulatory arrest during profound hypothermia

    OpenAIRE

    Astudillo Ley, Rafael

    1998-01-01

    Thirty-nine pediatric and 82 adult patients were studied during cardiac surgery with cardio pulmonary bypass (CPB) performed with moderate hypothermia or with deep hypothermia and circulatory arrest (DHCA) with or-without retrograde cerebral perfusion (RCP). Cerebral blood flow (CBF) was estimated from Doppler measurements of the blood velocity in the middle cerebral artery (MCAv). Arterio-venous (jugular bulb) differences of blood lactate and oxygen were used to study cereb...

  11. Effects of Hyperglycemia and Effects of Ketosis on Cerebral Perfusion, Cerebral Water Distribution, and Cerebral Metabolism

    OpenAIRE

    Glaser, Nicole; Ngo, Catherine; Anderson, Steven; Yuen, Natalie; Trifu, Alexandra; O’Donnell, Martha

    2012-01-01

    Diabetic ketoacidosis (DKA) may cause brain injuries in children. The mechanisms responsible are difficult to elucidate because DKA involves multiple metabolic derangements. We aimed to determine the independent effects of hyperglycemia and ketosis on cerebral metabolism, blood flow, and water distribution. We used magnetic resonance spectroscopy to measure ratios of cerebral metabolites (ATP to inorganic phosphate [Pi], phosphocreatine [PCr] to Pi, N-acetyl aspartate [NAA] to creatine [Cr], ...

  12. Effects of cerebral perfusion pressure on acute cerebral ischemia after traumatic brain injury%脑灌注压对创伤性脑损伤后急性脑缺血的影响

    Institute of Scientific and Technical Information of China (English)

    刘胜; 王诚; 刘远新; 吴涛; 郝建忠; 郭强

    2010-01-01

    目的 观察不同脑灌注压(CPP)对创伤性脑损伤后急性脑缺血的影响.方法 实验家兔60只,随机分为正常对照组(无损伤组)、高CPP组(90~110)mm Hg、中CPP组(70~80)mm Hg、低CPP组(50~60)mm Hg、极低CPP组(35~45)mm Hg.采用Feeney's自由落体撞击法建立急性局灶性脑挫裂伤模型,伤后80 min静脉给予升压和降压药物调控血压使CPP达到设计要求,同步进行脑血流、CPP测定,并进行图像分析,且观察不同CPP下颅脑损伤后急性脑缺血动物脑含水量及神经组织超微结构改变.结果 对照组局部脑血流量(rCBF)为156.18±6.22;高CPP组实验组rCBF为140.03±17.32,中CPP组rCBF为100.46±21.37,低CPP组rCBF为86.46±10.30,极低CPP组rCBF为60.36±8.32.对照组脑含水量为(78.21±0.26)%;高CPP组实验组脑含水量为(80.15±0.52)%,中CPP组脑含水量为(80.27±0.36)%,低CPP组脑含水量为(81.18±0.62)%,极低CPP组脑含水量为(81.34±0.83)%.实验组脑组织含水量高于对照组(P0.05).低CPP组及极低CPP组脑含水量、超微结构较对照组差异有统计学意义(P0.05). The changes in water content in brain and ultra-microstructures in nervous tissue in the low CPP group and the lower group were more significant than the control group (P<0.01). Conclusion To improve cerebral circulation availably is the important link to prevent the acute cerebral ischemia making the irreversible damage of brain after traumatic brain injury.

  13. 体位变化对脑室引流术患者颅内压和平均动脉压及脑灌注压的影响%Relation of position change to patients' intracranial pressure, cerebral perfusion pressure and mean arterial pressure after ventricle puncture and drainage

    Institute of Scientific and Technical Information of China (English)

    周薇

    2011-01-01

    目的 探讨脑室引流患者的体位变化对平均动脉压、颅内压和脑灌注压的影响.方法 对60例接受过脑室穿刺术并留置脑室引流管患者,监测其抬高床头0°、15°、30°、45°时的颅内压(ICP)和平均动脉压(MAP),再计算出脑灌注压(CPP),比较不同体位状态下患者的MAP、ICP和CPP.结果 ICP随着床头的抬高而显著降低(均P<0.01);CPP在0°与30°、45°体位,以及15°与45°体位时比较,差异有统计学意义(均P<0.01).结论 脑室引流患者床头抬高30°既能有效降低ICP,也可有效保证CPP.%Objective To investigate the relation of position changes to patients'intracranial pressure(ICP), cerebral perfusion pressure(CPP)and mean arterial pressure(MAP). Methods Totally, 60 patients who were treated by ventricle puncture and drainage therapy were recruited into the research. We monitored their ICP and MAP when the head of bed was raised from 0°to 15°, 30°,and 45°, and then we calculated the CPP at different angles. Results ICP was significantly decreased as the head of bed was elevated (P<0.01 for all). CPP at 0° head of bed position had significant differences with CPP at 30°, or 45°head of bed positions; CPP at 15° head of bed position had significant difference with CPP at 45°(P<0.01 for all). Conclusions The 30° head of bed position for paients after ventrical puncture and drainage can decreased ICP significantly and maintain stable CPP.

  14. Methodological NMR imaging developments to measure cerebral perfusion

    International Nuclear Information System (INIS)

    This work focuses on acquisition techniques and physiological models that allow characterization of cerebral perfusion by MRI. The arterial input function (AIF), on which many models are based, is measured by a technique of optical imaging at the carotid artery in rats. The reproducibility and repeatability of the AIF are discussed and a model function is proposed. Then we compare two techniques for measuring the vessel size index (VSI) in rats bearing a glioma. The reference technique, using a USPIO contrast agent (CA), faces the dynamic approach that estimates this parameter during the passage of a bolus of Gd. This last technique has the advantage of being used clinically. The results obtained at 4.7 T by both approaches are similar and use of VSI in clinical protocols is strongly encouraged at high field. The mechanisms involved (R1 and R2* relaxivities) were then studied using a multi gradient -echoes approach. A multi-echoes spiral sequence is developed and a method that allows the refocusing between each echo is presented. This sequence is used to characterize the impact of R1 effects during the passage of two successive injections of Gd. Finally, we developed a tool for simulating the NMR signal on a 2D geometry taking into account the permeability of the BBB and the CA diffusion in the interstitial space. At short TE, the effect of diffusion on the signal is negligible. In contrast, the effects of diffusion and permeability may be separated at long echo time. Finally we show that during the extravasation of the CA, the local magnetic field homogenization due to the decrease of the magnetic susceptibility difference at vascular interfaces is quickly balanced by the perturbations induced by the increase of the magnetic susceptibility difference at the cellular interfaces in the extravascular compartment. (author)

  15. Quantitative determination of cerebral perfusion with the aid of digital subtraction angiography (DSA)

    International Nuclear Information System (INIS)

    In a search for a reliable and relatively non-invasive method for quantifying cerebral perfusion, we examined the possible role of DSA. By using special software, it is possible to demonstrate vascular morphology and obtain functional data concerning blood flow. Regions of interest are used for obtaining time-density curves and these are evaluated by a formula designed by Meier and Zierler. Perfusion through the arterial territory in both cerebral hemispheres was correlated with the clinical symptoms of the patients and with the morphological findings. Difficulties and problems are described and discussed. (orig.)

  16. The quantitation of N-isopropyl-p-I-123 amphetamine cerebral perfusion and function studies

    International Nuclear Information System (INIS)

    A method of quantitatively analyzing ECT sections obtained from cerebral perfusion/function studies with N-isopropyl-p-I-123 Amphetamine (IMP) is presented and illustrated by a concrete case. This analysis makes use of six pairs of regions delineating the perfusion territories of the major cerebral arteries, and produces six right-left ratios which provide objective criteria to assess pathology and, in our opinion, is an important adjunct to visual interpretation of IMP studies. Even though quantitation of rCBF with IMP is highly desirable, no satisfactory method short of arterial input sampling seems to have been used so far to obtain absolute blood flow values. (orig.)

  17. Longitudinal Cerebral Perfusion Change in Transient Global Amnesia Related to Left Posterior Medial Network Disruption

    OpenAIRE

    Jang, Jae-Won; Park, Young Ho; Park, So Young; Wang, Min Jeong; Lim, Jae-Sung; Kim, Sung-Hun; Chun, In Kook; Yang, YoungSoon; Kim, SangYun

    2015-01-01

    Background The pathophysiology of transient global amnesia (TGA) is not fully understood. Previous studies using single photon emission computed tomography (SPECT) have reported inconclusive results regarding cerebral perfusion. This study was conducted to identify the patterns of regional cerebral blood flow (rCBF) in TGA patients via longitudinal SPECT analysis. An association between the observed SPECT patterns and a pathophysiological mechanism was considered. Methods Based on the TGA reg...

  18. Effect of isovolemic, isothermic hemodialysis on cerebral perfusion and vascular stiffness using contrast computed tomography and pulse wave velocity.

    Directory of Open Access Journals (Sweden)

    Ansgar Reising

    Full Text Available BACKGROUND: Patients undergoing hemodialysis treatment have a six-fold increased risk for stroke relative to the general population. However, the effect of hemodialysis on cerebral blood flow is poorly studied and confounding factors like blood pressure and ultrafiltration as well as temperature changes have rarely been accounted for. The aim of our study was to use state-of-the-art technology to evaluate the effect of a single dialysis session on cerebral perfusion as well as on vascular stiffness. METHODS: Chronic hemodialysis patients (7 male/3 female, mean age 58 years were recruited. Cerebral blood flow and arterial pulse wave velocity were measured before and immediately after a hemodialysis session. To exclude effects of volume changes we kept ultrafiltration to a minimum, allowing no change in body weight. Isothermic conditions were maintained by using the GENIUS single-pass batch-dialysis system with a high-flux polysulfone dialyser. Cerebral blood flow was measured by contrast-enhanced computed tomography. Pulse wave velocity was measured using the SphygmoCor (AtCor Medical, USA device by a single operator. RESULTS: This study shows for the first time that isovolemic, isothermic hemodialysis neither affected blood pressure or heart rate, nor total or regional cerebral perfusion. There was also no change in pulse wave velocity. CONCLUSIONS: Mechanisms other than the dialysis procedure itself might be causative for the high incidence of ischemic strokes in this patient population. Moreover, the sole removal of uremic toxins does not lead to short-term effects on vascular stiffness, underlying the importance of volume control in this patient population.

  19. Correcting partial volume artifacts of the arterial input function in quantitative cerebral perfusion MRI

    NARCIS (Netherlands)

    van Osch, MJP; Vonken, EJPA; Bakker, CJG; Viergever, MA

    2001-01-01

    To quantify cerebral perfusion with dynamic susceptibility contrast MRI (DSC-MRI), one needs to measure the arterial input function (AIF). Conventionally, one derives the contrast concentration from the DSC sequence by monitoring changes in either the amplitude or the phase signal on the assumption

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-15

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

  2. Noninvasive Cerebral Perfusion Imaging in High-Risk Neonates

    OpenAIRE

    Goff, Donna A.; Buckley, Erin M.; Durduran, Turgut; Wang, Jiongjong; Licht, Daniel J.

    2010-01-01

    Advances in medical and surgical care of the high-risk neonate have led to increased survival. A significant number of these neonates suffer from neurodevelopmental delays and failure in school. The focus of clinical research has shifted to understanding events contributing to neurological morbidity in these patients. Assessing changes in cerebral oxygenation and regulation of cerebral blood flow (CBF) is important in evaluating the status of the central nervous system. Traditional CBF imagin...

  3. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    Science.gov (United States)

    Blowers, Stephen; Valluri, Prashant; Marshall, Ian; Andrews, Peter; Harris, Bridget; Thrippleton, Michael

    2015-11-01

    Brain temperature relies heavily on two aspects: i) blood perfusion and porous heat transport through tissue and ii) blood flow and heat transfer through embedded arterial and venous vasculature. Moreover brain temperature cannot be measured directly unless highly invasive surgical procedures are used. A 3D two-phase fluid-porous model for mapping flow and temperature in brain is presented with arterial and venous vessels extracted from MRI scans. Heat generation through metabolism is also included. The model is robust and reveals flow and temperature maps in unprecedented 3D detail. However, the Karmen-Kozeny parameters of the porous (tissue) phase need to be optimised for expected perfusion profiles. In order to optimise the K-K parameters a reduced order two-phase model is developed where 1D vessels are created with a tree generation algorithm embedded inside a 3D porous domain. Results reveal that blood perfusion is a strong function of the porosity distribution in the tissue. We present a qualitative comparison between the simulated perfusion maps and those obtained clinically. We also present results studying the effect of scalp cooling on core brain temperature and preliminary results agree with those observed clinically.

  4. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs: a systematic review.

    Science.gov (United States)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward; Poulsen, Helle Harding; Moltke, Finn Borgbjerg; Eriksen, Thomas

    2016-01-01

    The objective of this review is to evaluate the existing literature with regard to the influence of propofol and remifentanil total intravenous anaesthesia (TIVA) on cerebral perfusion and oxygenation in healthy pigs. Anaesthesia has influence on cerebral haemodynamics and it is important not only in human but also in veterinary anaesthesia to preserve optimal regulation of cerebral haemodynamics. Propofol and remifentanil are widely used in neuroanaesthesia and are increasingly used in experimental animal studies. In translational models, the pig has advantages compared to small laboratory animals because of brain anatomy, metabolism, neurophysiological maturation, and cerebral haemodynamics. However, reported effects of propofol and remifentanil on cerebral perfusion and oxygenation in pigs have not been reviewed. An electronic search identified 99 articles in English. Title and abstract screening selected 29 articles for full-text evaluation of which 19 were excluded with reasons. Of the 10 peer-reviewed articles included for review, only three had propofol or remifentanil anaesthesia as the primary study objective and only two directly investigated the effect of anaesthesia on cerebral perfusion and oxygenation (CPO). The evidence evaluated in this systematic review is limited, not focused on propofol and remifentanil and possibly influenced by factors of potential importance for CPO assessment. In one study of healthy pigs, CPO measures were within normal ranges following propofol-remifentanil anaesthesia, and addition of a single remifentanil bolus did not affect regional cerebral oxygen saturation (rSO2). Even though the pool of evidence suggests that propofol and remifentanil alone or in combination have limited effects on CPO in healthy pigs, confirmative evidence is lacking. PMID:27334375

  5. Relations of blood pressure and head injury to regional cerebral blood flow.

    Science.gov (United States)

    Kisser, Jason E; Allen, Allyssa J; Katzel, Leslie I; Wendell, Carrington R; Siegel, Eliot L; Lefkowitz, David; Waldstein, Shari R

    2016-06-15

    Hypertension confers increased risk for cognitive decline, dementia, and cerebrovascular disease. These associations have been attributed, in part, to cerebral hypoperfusion. Here we posit that relations of higher blood pressure to lower levels of cerebral perfusion may be potentiated by a prior head injury. Participants were 87 community-dwelling older adults - 69% men, 90% white, mean age=66.9years, 27.6% with a history of mild traumatic brain injury (mTBI) defined as a loss of consciousness ≤30min resulting from an injury to the head, and free of major medical (other than hypertension), neurological or psychiatric comorbidities. All engaged in clinical assessment of systolic and diastolic blood pressure (SBP, DBP) and single photon emission computed tomography (SPECT). Computerized coding of the SPECT images yielded relative ratios of blood flow in left and right cortical and select subcortical regions. Cerebellum served as the denominator. Sex-stratified multiple regression analyses, adjusted for age, education, race, alcohol consumption, smoking status, and depressive symptomatology, revealed significant interactions of blood pressure and head injury to cerebral blood flow in men only. Specifically, among men with a history of head injury, higher systolic blood pressure was associated with lower levels of perfusion in the left orbital (β=-3.21, p=0.024) and left dorsolateral (β=-2.61, p=0.042) prefrontal cortex, and left temporal cortex (β=-3.36, p=0.014); higher diastolic blood pressure was marginally associated with lower levels of perfusion in the left dorsolateral prefrontal cortex (β=-2.79, p=0.051). Results indicate that men with a history of head injury may be particularly vulnerable to the impact of higher blood pressure on cerebral perfusion in left anterior cortical regions, thus potentially enhancing risk for adverse brain and neurocognitive outcomes. PMID:27206865

  6. Ictal cerebral perfusion patterns in partial epilepsy: SPECT subtraction

    International Nuclear Information System (INIS)

    To investigate the various ictal perfusion patterns and find the relationships between clinical factors and different perfusion patterns. Interictal and ictal SPECT and SPECT subtraction were performed in 61 patients with partial epilepsy. Both positive images showing ictal hyperperfusion and negative images revealing ictal hypoperfusion were obtained by SPECT subtraction. The ictal perfusion patterns of subtracted SPECT were classified into focal hyperperfusion, hyperperfusion-plus, combined hyperperfusion-hypoperfusion, and focal hypoperfusion only. The concordance rates with epileptic focus were 91.8% in combined analysis of ictal hyperperfusion and hypoperfusion images of subtracted SPECT, 85.2% in hyperperfusion images only of subtracted SPECT, and 68.9% in conventional ictal SPECT analysis. Ictal hypoperfusion occurred less frequently in temporal lobe epilepsy (TLE) than extratemporal lobe epilepsy. Mesial temporal hyperperfusion alone was seen only in mesial TLE while lateral temporal hyperperfusion alone was observed only in neocortical TLE. Hippocampal sclerosis had much lower incidence of ictal hypoperfusion than any other pathology. Some patients showed ictal hypoperfusion at epileptic focus with ictal hyperperfusion in the neighboring brain regions where ictal discharges propagated. Hypoperfusion as well as hyperperfusion in ictal SPECT should be considered for localizing epileptic focus. Although the mechanism of ictal hypoperfusion could be an intra-ictal early exhaustion of seizure focus or a steal phenomenon by the propagation of ictal discharges to adjacent brain areas, further study is needed to elucidate it.=20

  7. Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

    Directory of Open Access Journals (Sweden)

    Tomoyasu Takahiro

    2008-10-01

    Full Text Available Abstract Objective We examined the hypothesis that higher cerebral oxygen saturation (rSO2 during RCP is correlated with urinary output. Methods Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75% and Group B (rSO2 Results Seven and 5 patients were assigned to Group A and Group B, respectively. Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14 and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09 compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03. Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03. Conclusion Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.

  8. Statistical parametric mapping of Tc-99m HMPAO SPECT cerebral perfusion in the normal elderly

    Energy Technology Data Exchange (ETDEWEB)

    Turlakow, A.; Scott, A.M.; Berlangieri, S.U.; Sonkila, C.; Wardill, T.D.; Crowley, K.; Abbott, D.; Egan, G.F.; McKay, W.J.; Hughes, A. [Austin and Repatriation Medical Centre, Heidelberg, VIC (Australia). Departments of Nuclear Medicine and Centre for PET Neurology and Clinical Neuropsychology

    1998-06-01

    Full text: The clinical value of Tc-99m HMPAO SPECT cerebral blood flow studies in cognitive and neuropsychiatric disorders has been well described. Currently, interpretation of these studies relies on qualitative or semi- quantitative techniques. The aim of our study is to generate statistical measures of regional cerebral perfusion in the normal elderly using statistical parametric mapping (Friston et al, Wellcome Department of Cognitive Neurology, London, UK) in order to facilitate the objective analysis of cerebral blood flow studies in patient groups. A cohort of 20 healthy, elderly volunteers, aged 68 to 81 years, was prospectively selected on the basis of normal physical examination and neuropsychological testing. Subjects with risk factors, or a history of cognitive impairment were excluded from our study group. All volunteers underwent SPECT cerebral blood flow imaging, 30 minutes following the administration of 370 MBq Tc-99m HMPAO, on a Trionix Triad XLT triple-headed scanner (Trionix Research Laboratory Twinsburg, OH) using high resolution, fan-beam collimators resulting in a system resolution of 10 mm full width at half-maximum (FWHM). The SPECT cerebral blood flow studies were analysed using statistical parametric mapping (SPM) software specifically developed for the routine statistical analysis of functional neuroimaging data. The SPECT images were coregistered with each individual`s T1-weighted MR volume brain scan and spatially normalized to standardised Talairach space. Using SPM, these data were analyzed for differences in interhemispheric regional cerebral blood flow. Significant asymmetry of cerebral perfusion was detected in the pre-central gyrus at the 95th percentile. In conclusion, the interpretation of cerebral blood flow studies in the elderly should take into account the statistically significant asymmetry in interhemispheric pre-central cortical blood flow. In the future, clinical studies will be compared to statistical data sets in age

  9. Statistical parametric mapping of Tc-99m HMPAO SPECT cerebral perfusion in the normal elderly

    International Nuclear Information System (INIS)

    Full text: The clinical value of Tc-99m HMPAO SPECT cerebral blood flow studies in cognitive and neuropsychiatric disorders has been well described. Currently, interpretation of these studies relies on qualitative or semi- quantitative techniques. The aim of our study is to generate statistical measures of regional cerebral perfusion in the normal elderly using statistical parametric mapping (Friston et al, Wellcome Department of Cognitive Neurology, London, UK) in order to facilitate the objective analysis of cerebral blood flow studies in patient groups. A cohort of 20 healthy, elderly volunteers, aged 68 to 81 years, was prospectively selected on the basis of normal physical examination and neuropsychological testing. Subjects with risk factors, or a history of cognitive impairment were excluded from our study group. All volunteers underwent SPECT cerebral blood flow imaging, 30 minutes following the administration of 370 MBq Tc-99m HMPAO, on a Trionix Triad XLT triple-headed scanner (Trionix Research Laboratory Twinsburg, OH) using high resolution, fan-beam collimators resulting in a system resolution of 10 mm full width at half-maximum (FWHM). The SPECT cerebral blood flow studies were analysed using statistical parametric mapping (SPM) software specifically developed for the routine statistical analysis of functional neuroimaging data. The SPECT images were coregistered with each individual's T1-weighted MR volume brain scan and spatially normalized to standardised Talairach space. Using SPM, these data were analyzed for differences in interhemispheric regional cerebral blood flow. Significant asymmetry of cerebral perfusion was detected in the pre-central gyrus at the 95th percentile. In conclusion, the interpretation of cerebral blood flow studies in the elderly should take into account the statistically significant asymmetry in interhemispheric pre-central cortical blood flow. In the future, clinical studies will be compared to statistical data sets in age

  10. Monitoring cerebral perfusion after subarachnoid hemorrhage using CT

    International Nuclear Information System (INIS)

    The aim of this prospective study was to assess the feasibility and diagnostic relevance of repetitive dynamic (contrast-enhanced) CT measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the first 3 weeks after aneurysmal subarachnoid hemorrhage (SAH). In 15 patients with SAH, 59 dynamic CT studies including 944 regions of interest (ROI) were analyzed. The results were correlated with the clinical course and time after the event and the occurrence of vasospasm. Values for the entire series were 33.8 ± 19.3 ml/100 g/min (CBF), 3.3 ± 1.3 ml/100 g (CBV), and 7.3 ± 3.9 s (MTT). Significant differences in CBF and CBV were found between ROI in grey and white matter, with time after the event, between patients with significant and absent or minor vasospasm, and between patients with and without a presumed vasospasm-related infarct. (orig.)

  11. Cerebral perfusion changes in schizophrenia patients evaluated with Tc-99 HMPAO

    International Nuclear Information System (INIS)

    Tc-99m HMPAO has been used to image cerebral perfusion changes in 20 chronic schizophrenia patients (19 men and 1 woman), with an average age of 29 years (range, 22-48 years). All were receiving neuroleptic drugs. Twelve had received electroconvulsive therapy. All patients had abnormal studies (except one, which was normal) and poor response to treatment. Ventricular dilation and cerebral atrophy were seen in 11 patients. Seventy-seven focal lesions were detected. Forty-two lesions showed increased HMPAO retention: 26 in the basal ganglia in 14 patients (12, bilateral, two unilateral), 10 along the sylvian fissure in the parietotemporal region, three in the frontal region, and one in each of the temporal, parietal, and occipital regions. Thirty-five focal lesions showed decreased perfusion: 10 parietal, eight frontal, seven temporal, six cerebellar, and four occipital. This study demonstrates the potential value of Tc-99m HMPAO in the study of schizophrenia and other psychiatric disorders

  12. Demonstration of cerebral abnormalities in cocaine abusers with SPECT perfusion brain scans

    International Nuclear Information System (INIS)

    This paper reports I-123 isopropyl iodoamphetamine (IMP) single-photon emission CT (SPECT) brain scans performed on cocaine users to investigate the effects of cocaine on the cerebral perfusion in a manner similar to previous CT, angiographic and positron-emission tomographic (PET) studies. Ten asymptomatic or mildly symptomatic cocaine users, two users with major neurovascular complications, and five normal subjects were studied with IMP SPECT. Rotating-brain images of the cerebral IMP uptake were displayed by using a distance-weighted surface-projection technique and were visually analyzed for focal cortical perfusion deficits. Eleven cocaine users had multiple scattered cortical IMP defects. Frontal lobe defects were most prominent. One user had confluent defects resembling swiss cheese. Concurrent CT scans available in nine patients were negative in seven and showed infarcts in two. No similar focal findings were visible in normals

  13. Fatores associados a perfusão cerebral anormal em dependentes de cocaína

    OpenAIRE

    Silveira Dartiu X da; Fernandes Marcelo; Barbieri Antonio; Labigalini Eliseu; Silveira Evelyn D

    2001-01-01

    OBJETIVO: Avaliar a relação entre o padrão de uso da cocaína e a perfusão cerebral de dependentes da substância. MÉTODOS: Estudou-se uma amostra de 30 dependentes de cocaína por meio de tomografia computadorizada por emissão de fóton único (single photon emission computed tomography - SPECT) com hexametil-propileno-amina-oxima, marcada com tecnécio 99 m (99 m-Tc-HMPAO), e comparou-se o padrão de perfusão cerebral com o padrão de consumo da droga. RESULTADOS: Dos dependentes, 80% apresentaram ...

  14. Dynamic Changes of the CT Perfusion Parameters in the Embolic Model of Cerebral Ischemia

    Institute of Scientific and Technical Information of China (English)

    陈唯唯; 漆剑频; 张进华; 黄文华; 宋金梅

    2004-01-01

    To study the dynamic changes of CT perfusion parameters during the first 12 h in the embolic cerebral ischemia models. Local cerebral ischemia model were established in 7 New Zealand white rabbits. All CT scans were performed with a GE Lightspeed 16 multislice CT. Following the baseline scan, further CT perfusion scans were performed at the same locations 20 min, 1-6 h and8, 10 and 12 h after the embolus delivery. Maps of all parameters were obtained by CT perfusion software at each time point. The brains, taken 12 h after the scan, were sliced corresponding to the positions of the CT slices and stained by 2,3,5-triphenyltetrazolium chloride (TTC). On the basis of the TTC results, the ischemicsides were divided into 3 regions: core, penumbra and the relatively normal region. The changes of all parameters were then divided into 3 stages. In the first two hours (the first stage), the CBV dropped more remarkably in the core than in the penumbra but rose slightly in the relatively normal region while the CBF decreased and MTT, TTP extended in all regions to varying degrees. In the 2nd-5th h (the second stage), all the parameters fluctuated slightly around a certain level. In the 5th-12th h (the third stage), the CBV and CBF dropped,and MTT and TTP were prolonged or shortened slightly in the core and penumbra though much notably in the former while the CBV, CBF roseand MTT, TTP were shortened remarkably in the relatively normal region. We experimentally demonstrated that the location and extent of cerebral ischemia could be accurately assessed by CT perfusion imaging. The pathophysiology of the ischemia could be reflected by the CT perfusion to varying degrees.

  15. MR spectroscopy and MR perfusion character of cerebral sparganosis: a case report

    OpenAIRE

    Chiu, C-H; Chiou, T-L; Hsu, Y-H.; Yen, P-S

    2010-01-01

    The authors report the case of a 46-year-old woman with cerebral sparganosis resulting from infection with a larva of Spirometra. Computed tomography and magnetic resonance imaging revealed a mass lesion with prominent perifocal oedema in the left parietal lobe. Advanced imaging pulse sequences, including MR spectroscopy and MR perfusion, were performed. During surgery for the removal of a granuloma, the parasite was discovered and excised. Following treatment, the patient's neurological defi...

  16. Perfusion MR Imaging and Proton MR Spectroscopic Imaging in Differentiating Necrotizing Cerebritis from Glioblastoma Multiforme

    OpenAIRE

    Pivawer, Gabriel; Law, Meng; Zagzag, David

    2006-01-01

    We describe a lesion with the MR imaging characteristics of a glioblastoma mutiforme and demonstrate how perfusion MR imaging and proton MR spectroscopic imaging can be used to differentiate necrotizing cerebritis from what appeared to be a high-grade glioma. A 43 year old woman presented to her physician complaining of progressive visual disturbance and headache for several weeks. Conventional MR imaging demonstrated a parietal peripherally enhancing mass with central necrosis and moderate t...

  17. Cerebral abnormalities in cocaine abusers: Demonstration by SPECT perfusion brain scintigraphy. Work in progress

    International Nuclear Information System (INIS)

    Single photon emission computed tomography (SPECT) perfusion brain scans with iodine-123 isopropyl iodoamphetamine (IMP) were obtained in 12 subjects who acknowledged using cocaine on a sporadic to a daily basis. The route of cocaine administration varied from nasal to intravenous. Concurrent abuse of other drugs was also reported. None of the patients were positive for human immunodeficiency virus. Brain scans demonstrated focal defects in 11 subjects, including seven who were asymptomatic, and no abnormality in one. Among the findings were scattered focal cortical deficits, which were seen in several patients and which ranged in severity from small and few to multiple and large, with a special predilection for the frontal and temporal lobes. No perfusion deficits were seen on I-123 SPECT images in five healthy volunteers. Focal alterations in cerebral perfusion are seen commonly in asymptomatic drug users, and these focal deficits are readily depicted by I-123 IMP SPECT

  18. Association of frontal gray matter volume and cerebral perfusion in heroin addiction: A multimodal neuroimaging study

    Directory of Open Access Journals (Sweden)

    Niklaus eDenier

    2013-10-01

    Full Text Available Structure and function in the human healthy brain are closely related. In patients with chronic heroin exposure, brain imaging studies have identified long-lasting changes in gray matter (GM volume. More recently, we showed that acute application of heroin in dependent pa-tients results in hypoperfusion of fronto-temporal areas compared with the placebo condition. However, the relationship between structural and cerebral blood flow (CBF changes in heroin addiction has not yet been investigated. Moreover, it is not known whether there is any interaction between the chronic structural changes and the short and long term effects on per-fusion caused by heroin. Using a double-blind, within-subject design, heroin or placebo (saline was administrated to 15 heroin-dependent patients from a stable heroin-assisted treat-ment program, in order to observe acute short-term effects. Arterial spin labeling (ASL was used to calculate perfusion quantification maps in both treatment conditions, while Voxel Based Morphometry (VBM was conducted to calculate regional GM density. VBM and ASL data were used to calculate homologous correlation fields by Biological Parametric Mapping (BPM. We correlated each perfusion condition (heroin and placebo separately with a VBM sample that was identical for the two treatment conditions. It was assumed that heroin-associated perfusion is manifested in short term effects, while placebo-associated perfusion is more related to long term effects. Correlation analyses revealed a significant positive correlation in frontal and temporal areas between GM and both perfusion conditions (heroin and placebo. The heroin-associated perfusion was also negatively correlated with GM in the left thalamus and right cuneus. These findings indicate that, in heroin-dependent patients, low GM volume is positively associated with low perfusion within fronto-temporal regions.

  19. Perfusion and diffusion MR imaging of cerebral ischemia

    International Nuclear Information System (INIS)

    Currently, comparative studies applying magnetic resonance imaging for assessment of the clinical evolution of strokes are being performed at various centers, among them the center that has been supplying the images for this article. The studies aim at determining parameters that will permit more precise prognoses of lesion developments and particularly indicate the most appropriate treatment avoiding unwanted damage to the brain or even permitting recovery of brain fundtions. Truly reliable information for selection of treatment can yet not be derived from image interpretation. Available research results emphasize the value of MRI for diagnostic perfusion and diffusion imaging. As soon as the efficiency of aggressive treatment methods for acute strokes will have been proved and the logistic difficulties been resolved, allowing patients to be treated as in-patients as soon as possible after stroke attacks, MRI will certainly become the key modality for diagnostic evaluation and treatment planning. (orig./CB)

  20. A study of whole brain perfusion CT and CT angiography in hyperacute and acute cerebral infarction

    International Nuclear Information System (INIS)

    Objective: To evaluate the diagnostic value of whole-brain perfusion blood volume-weighted CT imaging (PWCT) and simultaneous CT angiography (CTA) on early stage of cerebral ischemic infarction. Methods: Non-contrast CT (NCCT), CT perfusion-weighted imaging (PWCT) and delayed CT (DCT) were conducted on 20 cases of early ischemic infarction of whose onset time ranged from 2 to 24 hours. All cases were reexamined with CT or MRI one week to one month later. CT values and perfusion blood volume (PBV) of central and peripheral low perfusion areas as well as those of collateral side were measured. CTA was reconstructed with PWCT as source images to evaluate occlusion or stenosis of blood vessel, and DCT was used to detect the collateral circulation. Results: Of the 20 cases, NCCT, PWCT and CTA were negative in 10 cases in which 6 were confirmed as Transient Ischemic Attack (TIA) on reexamined CT and clinical features, and the other 4 were confirmed as lacunar infarction. For the remaining 10 cases, a comparison was made with ANOVA between low perfusion area (central, peripheral inside and outside) and collateral side. The difference was significant (P<0.01). However, no significant difference was revealed in the central, peripheral inside and outside areas. PBV values were significant in low perfusion area and collateral side (P<0.05). The area of the final infarction was larger than that of the low perfusion area, and the percentage of enlargement exhibited medium negative correlation to the time of ischemia. CTA indicated that 2 cases suffered from left middle cerebral artery occlusion, meanwhile anterior and middle branches of MCA in the other 3 cases were not identified. The sensitivity of NCCT, PWCT and CTA were 28.5%, 71.4% and 35.7% respectively. DCT indicated that 5 cases had asymmetrical blood vessels. Conclusion: The whole-brain perfusion-weighted CT imaging and simultaneous CT angiography (CTA) is p roved to be a simple, timesaving and effective method for the

  1. RETROGRADE CEREBRAL PERFUSION AS METHOD OF BRAIN PROTECTION DURING OPERATIONS ON ASCENDING AND TRANSVERSE AORTA WITH HYPOTHERMIC CIRCULATORY ARREST

    Directory of Open Access Journals (Sweden)

    N. N. Tarabarko

    2011-01-01

    Full Text Available There is no optimal approach to cerebral protection during ascending and transverse aortic arch repairs in our days. This study was designed to analyze experience of using retrograde cerebral perfusion as method of brain protection during operations on ascending and transverse aorta with hypothermic circulatory arrest. 

  2. Intensive blood pressure control affects cerebral blood flow in type 2 diabetes mellitus patients

    DEFF Research Database (Denmark)

    Kim, Yu-Sok; Davis, Shyrin C A T; Truijen, Jasper;

    2011-01-01

    Type 2 diabetes mellitus is associated with microvascular complications, hypertension, and impaired dynamic cerebral autoregulation. Intensive blood pressure (BP) control in hypertensive type 2 diabetic patients reduces their risk of stroke but may affect cerebral perfusion. Systemic hemodynamic...... variables and transcranial Doppler-determined cerebral blood flow velocity (CBFV), cerebral CO2 responsiveness, and cognitive function were determined after 3 and 6 months of intensive BP control in 17 type 2 diabetic patients with microvascular complications (T2DM+), in 18 diabetic patients without (T2DM...... groups. However, in contrast to nondiabetic hypertensive patients, intensive BP control reduced CBFV in T2DM- (58±9 to 54±12 cm · s-1) and T2DM+ (57±13 to 52±11 cm · s-1) at 3 months, but CBFV returned to baseline at 6 months only in T2DM-, whereas the reduction in CBFV progressed in T2DM+ (to 48±8 cm...

  3. Single photon emission CT perfusion imaging of cerebral blood flow of early syphilis patients

    Institute of Scientific and Technical Information of China (English)

    施辛; 吴锦昌; 刘增礼; 唐军; 苏玉华

    2003-01-01

    Objective To injvestigate the cerebral blood flow of patients with early syphilis. Methods 99Tcm-ECD as brain perfusion imaging agent was used in single photon emission computed tomography (SPECT) for 32 patients with early syphilis and 15 controls. Visual analyses were made on every BSPECT image. Results The 32 patients with early syphilis had general, patchy hypoperfusion of cerebral blood flow. Fourteen of the 32 patients had 48 episodes of marked patchy hypoperfusion of rCBF. The responsible areas of hypoperfusion in a patchy distribution involved the left frontal lobe (6 episodes), right frontal lobe (3), left parietal lobe (7), right parietal lobe (6), left temporal lobe (11), right temporal lobe (5), left occipital lobe (3), left basal ganglia (3), cerebellum (1), and nerve nuceus (1). No abnormality was found in the control group.Conclusions Cerebral blood flow abnormalities exist in patients with early syphilis. General patchy hypoperfusion on SPECT imaging is common.

  4. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

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

    1994-01-01

    . Additional experiments were carried out using a higher spatial resolution. The largest signal increases were noted in areas corresponding to larger vessels, but significant changes were also conspicuous in deeper cortical and central grey matter. The changes appeared linearly related to the arterial CO2......The sensitivity of MR gradient echo imaging towards CO2 induced changes in cerebral blood flow was investigated in 10 normal subjects. The subjects were inhaling 5% and 7% CO2 and the experiments were carried out at 1.5 T (n = 6) and 2.0 T (n = 5), allowing a comparison of field strengths...... tension, within the range of PaCO2 studied. In white matter, the changes were not statistically significant....

  5. Correlative assessment of cerebral blood flow obtained with perfusion CT and positron emission tomography in symptomatic stenotic carotid disease

    International Nuclear Information System (INIS)

    Twelve patients with ICA stenosis underwent dynamic perfusion computed tomography (CT) and positron emission tomography (PET) studies at rest and after acetazolamide challenge. Cerebral blood flow (CBF) maps on perfusion CT resulted from a deconvolution of parenchymal time-concentration curves by an arterial input function (AIF) in the anterior cerebral artery as well as in both anterior choroidal arteries. CBF was measured by [15O]H2O PET using multilinear least-squares minimization procedure based on the one-compartment model. In corresponding transaxial PET scans, CBF values were extracted using standardized ROIs. The baseline perfusion CT-CBF values were lower in perfusion CT than in PET (P>0.05). CBF values obtained by perfusion CT were significantly correlated with those measured by PET before (P<0.05) and after (P<0.01) acetazolamide challenge. Nevertheless, the cerebrovascular reserve capacity was overestimated (P=0.05) using perfusion CT measurements. The AIF selection relative to the side of carotid stenosis did not significantly affect calculated perfusion CT-CBF values. In conclusion, the perfusion CT-CBF measurements correlate significantly with the PET-CBF measurements in chronic carotid stenotic disease and contribute useful information to the evaluation of the altered cerebral hemodynamics. (orig.)

  6. Vasopressin content in the cerebrospinal fluid and fluid perfusing cerebral ventricles in rats after the afferent vagus nerve fibres stimulation

    International Nuclear Information System (INIS)

    Experiments were carried out on male rats in urethane anaesthesia. Cerebroventricular system was perfused with McIlwain-Rodniht's solution from lateral ventricles to cerebellomedullary cistern. Both vagus nerves were cut and the central ends of the nerves were electrically stimulated during the collection of the third 30-min portion of perfusing fluid. Vasopressin (AVP) was determined by radioimmunoassay in samples of the cerebrospinal fluid (CSF) (the first portion) and in five successive samples of the perfusing fluid. AVP concentration in the CSF was several times greater than in the fluid perfusing cerebral ventricles. Alternate electrical stimulation of both vagus nerves did not change considerably the release of AVP into the fluid perfusing the cerebral ventricles in rat, although a certain upward tendency could be observed. It seems that only AVP raised in circulating blood and not in CSF, after vagus nerves stimulation may act on the central nervous structures. (author). 37 refs, 3 figs, 1 tab

  7. Vasopressin content in the cerebrospinal fluid and fluid perfusing cerebral ventricles in rats after the afferent vagus nerve fibres stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Orlowska-Majdak, M.; Traczyk, W.Z. [Akademia Medyczna, Lodz (Poland). Katedra Fizjologii

    1996-12-31

    Experiments were carried out on male rats in urethane anaesthesia. Cerebroventricular system was perfused with McIlwain-Rodniht`s solution from lateral ventricles to cerebellomedullary cistern. Both vagus nerves were cut and the central ends of the nerves were electrically stimulated during the collection of the third 30-min portion of perfusing fluid. Vasopressin (AVP) was determined by radioimmunoassay in samples of the cerebrospinal fluid (CSF) (the first portion) and in five successive samples of the perfusing fluid. AVP concentration in the CSF was several times greater than in the fluid perfusing cerebral ventricles. Alternate electrical stimulation of both vagus nerves did not change considerably the release of AVP into the fluid perfusing the cerebral ventricles in rat, although a certain upward tendency could be observed. It seems that only AVP raised in circulating blood and not in CSF, after vagus nerves stimulation may act on the central nervous structures. (author). 37 refs, 3 figs, 1 tab.

  8. Significance in diagnosis of acute cerebral ischemia by diffusion-weighted and perfusion-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Ikawa, Fusao; Kurisu, Kaoru; Arita, Kazunori; Migita, Keisuke; Akimitsu, Tomohide; Takeshita, Shinichiro; Chen, Shuda; Itoh, Katsuhide [Hiroshima Univ. (Japan). School of Medicine

    2000-07-01

    The purpose of this study was to diagnose acute stroke by diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) using echo planar imaging (EPI) with special reference to the corticospinal tract and hemodynamics. Six cases of acute stroke within 72 hours of onset were imaged with FLAIR, DWI and PWI. All studies were performed using a 1.5 T Signa Horizon MRI scanner (GE YMS). The imaging parameters of the DWI were employed in phase, frequency, and slice encode directions in four time frames; b=250, 500, 750, 1000 s/mm{sup 2}. DWI was imaged with single shot SE type EPI, TE=120 ms, matrix=100 x 100, 1 NEX, thickness 6 mm, FOV 40 cm. PWI was performed with single shot gradient echo type echo-planar technique during the injection of 0.2 mmol per kilogram of body weight of gadopentate dimeglumine, TE=42 ms, matrix=128 x 128, 1 NEX, thickness 6 mm, FOV 30 cm. Apparent diffusion coefficient (ADC) map, relative cerebral blood volume (rCBV) map, and relative mean transit time (rMTT) map were reconstructed by workstation. All six acute infarctions could be imaged by DWI. In phase directional DWI, the relationship between infarction and corticospinal tract was easily detected. A perfusion map could reveal a larger area with disturbance of hemodynamics around the acute infarction. In conclusion, diffusion-weighted imaging was useful for the diagnosis of acute stage cerebral infarction. Perfusion-weighted imaging was useful as a simple model of cerebral hemodynamics in cerebral infarction. (author)

  9. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  10. Arterial pressure and cerebral blood flow variability: friend or foe? A review

    Directory of Open Access Journals (Sweden)

    CarolineAliceRickards

    2014-04-01

    Full Text Available Variability in arterial pressure and cerebral blood flow has traditionally been interpreted as a marker of cardiovascular decompensation, and has been associated with negative clinical outcomes across varying time scales, from impending orthostatic syncope to an increased risk of stroke. Emerging evidence, however, suggests that increased hemodynamic variability may, in fact, be protective in the face of acute challenges to perfusion, including significant central hypovolemia and hypotension (including hemorrhage, and during cardiac bypass surgery. This review presents the dichotomous views on the role of hemodynamic variability on clinical outcome, including the physiological mechanisms underlying these patterns, and the potential impact of increased and decreased variability on cerebral perfusion and oxygenation. We suggest that reconciliation of these two apparently discrepant views may lie in the time scale of hemodynamic variability; short time scale variability appears to be cerebroprotective, while mid to longer term fluctuations are associated with primary and secondary end-organ dysfunction.

  11. Evaluation of cerebral perfusion imaging with N-isopropyl-p-[{sup 123}I]iodoamphetamine (IMP) in the cases of antiphospholipid syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Toru; Nanbu, Ichiro; Tohyama, Junko; Ohba, Satoru [Nagoya City Univ. (Japan). Faculty of Medicine

    1995-01-01

    Five cases of antiphospholipid syndrome with mild headache, but without any neurological deficits and abnormal findings by CT and MRI, were examined by cerebral blood perfusion SPECT using N-isopropyl-p-[{sup 123}I] iodoamphetamine (IMP). Although three cases were performed quantification of cerebral blood flow with a microsphere method simultaneously, their values were within normal limits. Two of them showed focal low perfusion areas. One case had relatively low perfusion areas in the bilateral occipital lobes and the right temporal lobe, which improved after treatment. One of two had low perfusion in the bilateral occipital lobes. Other three cases only showed ununiformity of radioisotope uptake on the cerebral blood perfusion SPECT. Low perfusion areas in antiphospholipid syndrome might be caused by microarterial thrombosis, microvenous thrombosis or spasms, although they could be reversible. As early irreversible progress of cerebral blood flow, cerebral blood flow SPECT should be performed in cases of antiphospholipid syndrome with neurological complainments. (author).

  12. Evaluation of cerebral perfusion imaging with N-isopropyl-p-[123I]iodoamphetamine (IMP) in the cases of antiphospholipid syndrome

    International Nuclear Information System (INIS)

    Five cases of antiphospholipid syndrome with mild headache, but without any neurological deficits and abnormal findings by CT and MRI, were examined by cerebral blood perfusion SPECT using N-isopropyl-p-[123I] iodoamphetamine (IMP). Although three cases were performed quantification of cerebral blood flow with a microsphere method simultaneously, their values were within normal limits. Two of them showed focal low perfusion areas. One case had relatively low perfusion areas in the bilateral occipital lobes and the right temporal lobe, which improved after treatment. One of two had low perfusion in the bilateral occipital lobes. Other three cases only showed ununiformity of radioisotope uptake on the cerebral blood perfusion SPECT. Low perfusion areas in antiphospholipid syndrome might be caused by microarterial thrombosis, microvenous thrombosis or spasms, although they could be reversible. As early irreversible progress of cerebral blood flow, cerebral blood flow SPECT should be performed in cases of antiphospholipid syndrome with neurological complainments. (author)

  13. Retinal vessel diameter changes induced by transient high perfusion pressure

    Institute of Scientific and Technical Information of China (English)

    Yin-Ying; Zhao; Ping-Jun; Chang; Fang; Yu; Yun-E; Zhao

    2014-01-01

    ·AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells.·METHODS: The animals were divided into four groups according to different infusion pressure and infusion time(60 mm Hg-3min, 60 mm Hg-5min, 100 mm Hg-3min, 100 mm Hg-5min). Each group consisted of six rabbits. The left eye was used as the experimental eye and the right as a control. Retinal vascular diameters were evaluated before, during infusion, immediately after infusion, 5min, 10 min and 30 min after infusion based on the fundus photographs. Blood pressure was monitored during infusion. The eyes were removed after 24 h.Damage to retinal ganglion cell(RGC) was analyzed by histology.·RESULTS: Retina became whiten and papilla optic was pale during perfusion. Measurements showed significant decrease in retinal artery and vein diameter during perfusion in all of the four groups at the proximal of the edge of the optic disc. The changes were significant in the 100 mm Hg-3min group and 100 mm Hg-5min group compared with 60 mm Hg-3min group(P 1=0.025, P 2=0.000).The diameters in all the groups recovered completely after 30 min of reperfusion. The number of RGC)showed no significant changes at the IOP in 100 mm Hg with5 min compared with contralateral untreated eye(P >0.05).·CONCLUSION: Transient fluctuations during infusion lead to temporal changes of retinal vessels, which could affect the retinal blood circulation. The RGCs were not affected by this transient fluctuation. Further studies are necessary to evaluate the effect of pressure during realtime phacoemusification on retinal blood circulation.

  14. Pathophysiology of cerebral circulatory disorders in idiopathic normal pressure hydrocephalus

    International Nuclear Information System (INIS)

    This study was conducted to elucidate the pathologic conditions of cerebral circulatory disorders in idiopathic normal pressure hydrocephalus (iNPH). Among 44 possible iNPH patients, 40 patients underwent shunt surgery based on diagnostic flow charts plotted by the Southern Tohoku method and were evaluated to be shunt-effective at the end of the first post-surgical month. The cerebral blood flow (CBF) was measured by N-isopropyl-(123I)-P-iodo-amphetamine single photon emission computed tomography (mean, mCBF; cortical region, cCBF; thalamus-basal ganglia region, tbCBF on autoradiography [ARG] method) and the perfusion patterns of the cerebral cortex were measured based on three-dimensional stereotactic surface projection (3D-SSP) Z-score images, before and 1 month after the surgery in all 40 subjects. The mCBF rose significantly from 32.1±2.74 ml/100 g/min before surgery to 39.8±3.02 ml/100 g/min after surgery (p<0.03). Investigation of the change of CBF revealed reductions in the cCBF (3 cases), tbCBF (9 cases), and cCBF+tbCBF (28 cases), with the reduced-cCBF group totaling 31 cases and the reduced-tbCBF group totaling 37 cases. Investigation of cerebral cortex hypoperfusion by 3D-SSP Z-score revealed 31 cases with hypoperfusion (frontal lobe type [19 cases], occipitotemporal lobe type [5 cases], mixed type [7 cases]) and nine cases with cortical normoperfusion (N). The pattern of reduction of the cortical blood flow on ARG method was favorably correlated with the pattern of hypoperfusion of the cerebral cortex on 3D-SSP Z-score images before surgery. A reduction of blood flow was found in the thalamus-basal ganglia region of all N type cases. The blood flow improved in 19 of 31 (61.3%) cases of the reduced-cCBF group and in 32 of 37 (86.5%) cases of the reduced-tbCBF group. All of the cases without detectable improvement exhibited increased blood flow in non-reduction areas. Investigation of the hypoperfusion patterns of the cerebral cortex on 3D-SSP Z

  15. Arterial spin labelling MRI for assessment of cerebral perfusion in children with moyamoya disease: comparison with dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Goetti, Robert [University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland); University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); O' Gorman, Ruth [University Children' s Hospital Zurich, Center for MR Research, Zurich (Switzerland); Khan, Nadia [University Children' s Hospital Zurich, Moyamoya Center, Division of Neurosurgery, Department of Surgery, Zurich (Switzerland); Kellenberger, Christian J.; Scheer, Ianina [University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland)

    2013-05-15

    This study seeks to evaluate the diagnostic accuracy of cerebral perfusion imaging with arterial spin labelling (ASL) MR imaging in children with moyamoya disease compared to dynamic susceptibility contrast (DSC) imaging. Ten children (7 females; age, 9.2 {+-} 5.4 years) with moyamoya disease underwent cerebral perfusion imaging with ASL and DSC on a 3-T MRI scanner in the same session. Cerebral perfusion images were acquired with ASL (pulsed continuous 3D ASL sequence, 32 axial slices, TR = 5.5 s, TE = 25 ms, FOV = 24 cm, matrix = 128 x 128) and DSC (gradient echo EPI sequence, 35 volumes of 28 axial slices, TR = 2,000 ms, TE = 36 ms, FOV = 24 cm, matrix = 96 x 96, 0.2 ml/kg Gd-DOTA). Cerebral blood flow maps were generated. ASL and DSC images were qualitatively assessed regarding perfusion of left and right ACA, MCA, and PCA territories by two independent readers using a 3-point-Likert scale and quantitative relative cerebral blood flow (rCBF) was calculated. Correlation between ASL and DSC for qualitative and quantitative assessment and the accuracy of ASL for the detection of reduced perfusion per territory with DSC serving as the standard of reference were calculated. With a good interreader agreement ({kappa} = 0.62) qualitative perfusion assessment with ASL and DSC showed a strong and significant correlation ({rho} = 0.77; p < 0.001), as did quantitative rCBF (r = 0.79; p < 0.001). ASL showed a sensitivity, specificity and accuracy of 94 %, 93 %, and 93 % for the detection of reduced perfusion per territory. In children with moyamoya disease, unenhanced ASL enables the detection of reduced perfusion per vascular territory with a good accuracy compared to contrast-enhanced DSC. (orig.)

  16. Arterial spin labelling MRI for assessment of cerebral perfusion in children with moyamoya disease: comparison with dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    This study seeks to evaluate the diagnostic accuracy of cerebral perfusion imaging with arterial spin labelling (ASL) MR imaging in children with moyamoya disease compared to dynamic susceptibility contrast (DSC) imaging. Ten children (7 females; age, 9.2 ± 5.4 years) with moyamoya disease underwent cerebral perfusion imaging with ASL and DSC on a 3-T MRI scanner in the same session. Cerebral perfusion images were acquired with ASL (pulsed continuous 3D ASL sequence, 32 axial slices, TR = 5.5 s, TE = 25 ms, FOV = 24 cm, matrix = 128 x 128) and DSC (gradient echo EPI sequence, 35 volumes of 28 axial slices, TR = 2,000 ms, TE = 36 ms, FOV = 24 cm, matrix = 96 x 96, 0.2 ml/kg Gd-DOTA). Cerebral blood flow maps were generated. ASL and DSC images were qualitatively assessed regarding perfusion of left and right ACA, MCA, and PCA territories by two independent readers using a 3-point-Likert scale and quantitative relative cerebral blood flow (rCBF) was calculated. Correlation between ASL and DSC for qualitative and quantitative assessment and the accuracy of ASL for the detection of reduced perfusion per territory with DSC serving as the standard of reference were calculated. With a good interreader agreement (κ = 0.62) qualitative perfusion assessment with ASL and DSC showed a strong and significant correlation (ρ = 0.77; p < 0.001), as did quantitative rCBF (r = 0.79; p < 0.001). ASL showed a sensitivity, specificity and accuracy of 94 %, 93 %, and 93 % for the detection of reduced perfusion per territory. In children with moyamoya disease, unenhanced ASL enables the detection of reduced perfusion per vascular territory with a good accuracy compared to contrast-enhanced DSC. (orig.)

  17. Contractile responses to ergotamine and dihydroergotamine in the perfused middle cerebral artery of rat

    DEFF Research Database (Denmark)

    Tfelt-Hansen, Peer; Nilsson, Elisabeth; Edvinsson, Lars

    2007-01-01

    The vasomotor effects of ergotamine and dihydroergotamine (DHE) on the middle cerebral artery (MCA) of rats were studied using the pressurised arteriography method and in vitro myographs. MCAs from Sprague-Dawley rats were mounted on two glass micropipettes using the arteriograph, pressurised to 85...... mmHg and luminally perfused. All vessels used attained spontaneous contractile tone (34.9+/-1.8% of resting tone) and responded to luminal adenosine triphosphate (ATP) with dilatation (24.1+/-4.0%), which showed functioning endothelium. Luminally added ergotamine or DHE induced maximal contractions...... of 16.8+8% and 22.4+/-0.9%, respectively, compared to the resting diameter, with a pEC(50) of 8.7+/-0.1 for ergotamine and 9.0+/-0.1 for DHE. Abluminal application of ergotamine and DHE also caused concentration-dependent contractions of the perfused MCA by 21.4+/-2.1% and 23.1+/-7.0%, respectively...

  18. 99mTc-ECD brain perfusion SPECT imaging for the assessment of brain perfusion in cerebral palsy (CP) patients with evaluation of the effect of hyperbaric oxygen therapy

    OpenAIRE

    Asl, Mina Taghizadeh; Yousefi, Farzaneh; Nemati, Reza; Assadi, Majid

    2015-01-01

    Objective: The present study was carried out to evaluate cerebral perfusion in different types of cerebral palsy (CP) patients. For those patients who underwent hyperbaric oxygen therapy, brain perfusion before and after the therapy was compared. Methods: A total of 11 CP patients were enrolled in this study, of which 4 patients underwent oxygen therapy. Before oxygen therapy and at the end of 40 sessions of oxygen treatment, 99mTc-ECD brain perfusion single photon emission computed tomograph...

  19. Vascular risk factors, atherosclerosis, cerebral white matter lesions and cerebral perfusion in a population-based study

    International Nuclear Information System (INIS)

    We studied risk factors for cerebral vascular disease (blood pressure and hypertension, factor VIIc, factor VIIIc, fibrinogen), indicators of atherosclerosis (intima-media thickness and plaques in the carotid artery) and cerebral white matter lesions in relation to regional cerebral blood flow (rCBF) in 60 persons (aged 65-85 years) recruited from a population-based study. rCBF was assessed with single-photon emission tomography using technetium-99m d,l-hexamethylpropylene amine oxime (99mTc-HMPAO). Statistical analysis was performed with multiple linear regression with adjustment for age, sex and ventricle-to-brain ratio. A significant positive association was found between systolic and diastolic blood pressure and temporo-parietal rCBF. In analysis with quartiles of the distribution, we found a threshold effect for the relation of low diastolic blood pressure (≤60 mmHg) and low temporo-parietal rCBF. Levels of plasma fibrinogen were inversely related to parietal rCBF, with a threshold effect of high fibrinogen levels (>3.2 g/l) and low rCBF. Increased atherosclerosis was related to low rCBF in all cortical regions, but these associations were not significant. No consistent relation was observed between severity of cerebral white matter lesions and rCBF. Our results may have implications for blood pressure control in the elderly population. (orig.)

  20. Contractile responses to ergotamine and dihydroergotamine in the perfused middle cerebral artery of rat

    OpenAIRE

    Tfelt-Hansen, Peer; Nilsson, Elisabeth; Edvinsson, Lars

    2007-01-01

    The vasomotor effects of ergotamine and dihydroergotamine (DHE) on the middle cerebral artery (MCA) of rats were studied using the pressurised arteriography method and in vitro myographs. MCAs from Sprague–Dawley rats were mounted on two glass micropipettes using the arteriograph, pressurised to 85 mmHg and luminally perfused. All vessels used attained spontaneous contractile tone (34.9±1.8% of resting tone) and responded to luminal adenosine triphosphate (ATP) with dilatation (24.1±4.0%), wh...

  1. Regional cerebral blood flow autoregulation in patients with fulminant hepatic failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Strauss, Gitte Irene; Møller, Kirsten;

    2000-01-01

    The absence of cerebral blood flow autoregulation in patients with fulminant hepatic failure (FHF) implies that changes in arterial pressure directly influence cerebral perfusion. It is assumed that dilatation of cerebral arterioles is responsible for the impaired autoregulation. Recently, fronta...

  2. Measurement of cerebral perfusion and haemodynamic reserve by SPECT: application to cerebrovascular disease

    International Nuclear Information System (INIS)

    The isolated measurement of cerebral blood flow can lead to gross errors in vascular disease, particularly ischaemic disease, because of disruption of the relations between blood flow and metabolism. In contrast, the measurement of cerebral blood flow combined with measurement of the haemodynamic reserve overcomes these difficulties, regardless of the method of evaluation: reactivity to CO2 or to acetazolamide; measurement of the flow volume ratio. The author demonstrates that these measurements are even more valuable in situations in which morphological examinations (MRI or computed tomography) are of little value: transient ischaemic attacks, asymptomatic carotid artery stenosis, etc. However, these measurements are useful in constituted infarctions or in vasospasm to assess the distant effects or to guide the therapeutic adjustment or even to provide prognostic elements. Combined measurement of perfusion and haemodynamic reserve, although it does not constitute a formal proof, is now largely accessible by means of non-specialized gamma cameras with determination of the flow/volume ratio

  3. SPECTCT cerebral perfusion scintigraphy; is the low-dose CT component of diagnostic value?

    International Nuclear Information System (INIS)

    Aim: To assess the potential diagnostic value of the low-dose computed tomography (CT) component of dual-examination single photon emission CT and CT (SPECTCT) cerebral perfusion studies. Method and materials: Two hundred and forty consecutive 99 mTc hexamethylpropylene amine oxime (HMPAO) SPECTCT studies were considered for inclusion. The images were acquired on a hybrid dual-head gamma camera/low-dose CT system. The CT component had a fixed tube current of 2.5 mA. The CT section thickness was 5 mm and total acquisition time approximately 7.5 min. Studies in which no CT images were acquired, or those excessively degraded by movement artefact were excluded. The CT images of each of the remaining studies were retrospectively reviewed and categorized as normal or abnormal. Details of the abnormalities were recorded. Results: Fifteen of the 240 studies were excluded as no CT images were obtained. A further 14 were excluded as they were considered excessively degraded by movement artefact. A single abnormality was demonstrated on 48 (23%), and two abnormalities on four (2%) of the remaining 211 studies. The most common abnormal findings were low attenuation in the deep cortical white matter (n = 22), infarcts (n = 12), cerebral atrophy (n = 7), dilated ventricles (n = 5), basal ganglia calcification (n = 4), and post-surgical change (n = 3). Other findings included a chronic subdural haematoma, a meningioma, and a posterior fossa cyst. Previous cerebral imaging was available for comparison in 31% of cases. There was 85% concordance between previous imaging and the low-dose CT images. Conclusion: Twenty-five percent of the low-dose CT images in this study demonstrated abnormalities. Therefore the CT component of cerebral perfusion SPECTCT investigations should be routinely reported in their own right

  4. Cerebral perfusion and neuropsychological follow up in mild traumatic brain injury: acute versus chronic disturbances?

    Science.gov (United States)

    Metting, Zwany; Spikman, Jacoba M; Rödiger, Lars A; van der Naalt, Joukje

    2014-04-01

    In a subgroup of patients with mild traumatic brain injury (TBI) residual symptoms, interfering with outcome and return to work, are found. With neuropsychological assessment cognitive deficits can be demonstrated although the pathological underpinnings of these cognitive deficits are not fully understood. As the admission computed tomography (CT) often is normal, perfusion CT imaging may be a useful indicator of brain dysfunction in the acute phase after injury in these patients. In the present study, directly after admission perfusion CT imaging was performed in mild TBI patients with follow-up neuropsychological assessment in those with complaints and a normal non-contrast CT. Neuropsychological tests comprised the 15 Words test Immediate Recall, Trailmaking test part B, Zoo Map test and the FEEST, which were dichotomized into normal and abnormal. Perfusion CT results of patients with normal neuropsychological test scores were compared to those with abnormal test scores. In total eighteen patients were included. Those with an abnormal score on the Zoo Map test had a significant lower CBV in the right frontal and the bilateral parieto-temporal white matter. Patients with an abnormal score on the FEEST had a significant higher MTT in the bilateral frontal white matter and a significant decreased CBF in the left parieto-temporal grey matter. No significant relation between the perfusion CT parameters and the 15 Words test and the Trailmaking test part B was present. In conclusion, impairments in executive functioning and emotion perception assessed with neuropsychological tests during follow up were related to differences in cerebral perfusion at admission in mild TBI. The pathophysiological concept of these findings is discussed. PMID:24556319

  5. The effect of ventricular assist devices on cerebral blood flow and blood pressure fractality

    International Nuclear Information System (INIS)

    Biological signals often exhibit self-similar or fractal scaling characteristics which may reflect intrinsic adaptability to their underlying physiological system. This study analysed fractal dynamics of cerebral blood flow in patients supported with ventricular assist devices (VAD) to ascertain if sustained modifications of blood pressure waveform affect cerebral blood flow fractality. Simultaneous recordings of arterial blood pressure and cerebral blood flow velocity using transcranial Doppler were obtained from five cardiogenic shock patients supported by VAD, five matched control patients and five healthy subjects. Computation of a fractal scaling exponent (α) at the low-frequency time scale by detrended fluctuation analysis showed that cerebral blood flow velocity exhibited 1/f fractal scaling in both patient groups (α = 0.95 ± 0.09 and 0.97 ± 0.12, respectively) as well as in the healthy subjects (α = 0.86 ± 0.07). In contrast, fluctuation in blood pressure was similar to non-fractal white noise in both patient groups (α = 0.53 ± 0.11 and 0.52 ± 0.09, respectively) but exhibited 1/f scaling in the healthy subjects (α = 0.87 ± 0.04, P < 0.05 compared with the patient groups). The preservation of fractality in cerebral blood flow of VAD patients suggests that normal cardiac pulsation and central perfusion pressure changes are not the integral sources of cerebral blood flow fractality and that intrinsic vascular properties such as cerebral autoregulation may be involved. However, there is a clear difference in the fractal scaling properties of arterial blood pressure between the cardiogenic shock patients and the healthy subjects

  6. Challenges in understanding the impact of blood pressure management on cerebral oxygenation in the preterm brain

    Directory of Open Access Journals (Sweden)

    Aminath eAzhan

    2012-12-01

    Full Text Available Systemic hypotension in preterm infants has been related to increased mortality, cerebrovascular lesions and neurodevelopmental morbidity. Treatment of hypotension with inotropic medications aims at preservation of end organ perfusion and oxygen delivery, especially the brain. The common inotropic medications in preterm infants include dopamine, dobutamine, adrenalin, with adjunctive use of corticosteroids in cases of refractory hypotension. Whether maintenance of mean arterial blood pressure (MAP by use of inotropic medication is neuroprotective or not remains unclear. This review explores the different inotropic agents and their effects on perfusion and oxygenation in the preterm brain, in clinical studies as well as in animal models. Dopamine and adrenalin, because of their -adrenergic vasoconstrictor actions, have raised concerns of reduction in cerebral blood flow (CBF. Several studies in hypotensive preterm infants have shown that dopamine elevates CBF together with increased MAP, in keeping with limited cerebro-autoregulation. Adrenaline is also effective in raising cerebral perfusion together with MAP in preterm infants. Experimental studies in immature animals show no cerebro-vasoconstrictive effects of dopamine or adrenaline, but demonstrate the consistent findings of increased cerebral perfusion and oxygenation with the use of dopamine, dobutamine and adrenaline, alongside with raised MAP. Both clinical and animal studies report the transitory effects of adrenaline in increasing plasma lactate, and blood glucose, which might render its use as a 2nd line therapy. To investigate the cerebral effects of inotropic agents in long-term outcome in hypotensive preterm infants, carefully designed prospective research possibly including preterm infants with permissive hypotension is required. Preterm animal models would be useful in investigating the relationship between the physiological effects of inotropes and histopathology outcomes in

  7. Early cerebral circulatory disturbance in patients suffering subarachnoid hemorrhage prior to the delayed cerebral vasospasm stage. Xenon computed tomography and perfusion computed tomography study

    International Nuclear Information System (INIS)

    Subarachnoid hemorrhage (SAH) causes dynamic changes in cerebral blood flow (CBF), and results in delayed ischemia due to vasospasm, and early perfusion deficits before delayed cerebral vasospasm (CVS). The present study examined the severity of cerebral circulatory disturbance during the early phase before delayed CVS and whether it can be used to predict patient outcome. A total of 94 patients with SAH underwent simultaneous xenon computed tomography (CT) and perfusion CT to evaluate cerebral circulation on Days 1-3. Cerebral blood flow (CBF) was measured using xenon CT and the mean transit time (MTT) using perfusion CT and calculated cerebral blood volume (CBV). Outcome was evaluated with the Glasgow Outcome Scale (good recovery [GR], moderate disability [MD], severe disability [SD], vegetative state [VS], or death [D]). Hunt and Hess (HH) grade II patients displayed significantly higher CBF and lower MTT than HH grade IV and V patients. HH grade III patients displayed significantly higher CBF and lower MTT than HH grade IV and V patients. Patients with favorable outcome (GR or MD) had significantly higher CBF and lower MTT than those with unfavorable outcome (SD, VS, or D). Discriminant analysis of these parameters could predict patient outcome with a probability of 74.5%. Higher HH grade on admission was associated with decreased CBF and CBV and prolonged MTT. CBF reduction and MTT prolongation before the onset of delayed CVS might influence the clinical outcome of SAH. These parameters are helpful for evaluating the severity of SAH and predicting the outcomes of SAH patients. (author)

  8. Preparation and animal studies of a novel potential cerebral perfusion imaging agent

    International Nuclear Information System (INIS)

    Objective: To investigate a novel potential SPECT cerebral blood flow perfusion imaging agent. Methods: N2S tridentate α-mercaptol-propyl-1, 2-benzenediamine (MPBDA) was obtained from chemical synthesis IR and was labelled with 99Tcm. Biodistribution analysis in 25 mice was performed after intravenous injection of 100 μL 555 - 740 kBq of 99Tcm-MPBDA. Dynamic acquisition was performed after rapid intravenous injection of 218.3 - 333 MBq 99Tc-MPBDA or 99Tcm-ECD, while whole body imaging and brain perfusion imaging were done after 70 min in 2 normal monkeys. Preclinical studies including toxicity and pyrogen tests in mice and rabbits were undertaken. Results: The radiochemical synthetic yield and radiochemical purity of MPBDA labelled with 99Tcm were more than 95% and 97%, respectively. Mice biodistribution test showed the 99Tcm-MPBDA can concentrate in brain with good retention, and blood clearance Ty2 99Tcm-ECD (2.9% ID). SPECT imaging of cerebral gray and white matter showed good contrast with a clear contour. No toxic side affect in mice and rabbits after 99Tcm-MPBDA injection was found. Conclusion: Investigated 99Tcm-MPBDA has almost the same property as 99Tcm-ECD. It is safe and reliable in vivo

  9. Cerebral perfusion disorders in patients after craniocerebral injury with clinical temporal conus syndrome

    International Nuclear Information System (INIS)

    Aim: to evaluate the changes of cerebral perfusion in patients after craniocerebral injury with clinical temporal conus syndrome. Material and methods: We present a group of 14 head injured patients admitted to neurosurgery with the syndrome of temporal herniation (Glasgow coma scale 3 - 5, homorateral dilated pupil and disturbed vital functions). There were 7 epidural, 6 subdural and one intracerebral hematomas. Mean age was 42, 7. All patients had urgent surgery and then continuous monitoring of vital functions. Results: Two postoperative CT and SPECT examinations were performed in each patient. Only 2 patients had visible ischemia on the first postoperative CT scan, both diet. 11 patients had ischemia in both the first post-operative and the follow up SPECT. 7 patients had improvement on the follow up SPECT compared to the first one, 6 of them were good results, one died. Conclusions: SPECT is very sensitive to impaired cerebral perfusion and may be helpful as a serial study. This is very mainly in the patients with reversible ischemia which may be influenced therapeutically with good results

  10. Use of /sup 81m/Kr for diagnosis of pulmonary embolism and for assessment of cerebral perfusion

    International Nuclear Information System (INIS)

    Continuous inhalation of krypton-81m provides functional images of pulmonary ventilation in multiple views. These can be obtained without cooperation on the part of the patient and in the same session on a technetium-99m perfusion scan. Multiple view ventilation-perfusion study is routinely used for the differential diagnosis of acute pulmonary disorders. In pulmonary embolism, multiple segmental defects on the perfusion scan are associated with a normal ventilation. Parenchymal lung disease and bronchitis share matching defects of both perfusion and ventilation. Continuous carotid infusion of /sup 81m/Kr affords an assessment of cerebral perfusion. The association of carotid infusion of /sup 81m/Kr in single-photon emission computerized tomography provides a tridimensional assessment of brain blood flow, which can be displayed in horizontal, sagittal, or frontal sections

  11. CT perfusion during delayed cerebral ischemia after subarachnoid hemorrhage: distinction between reversible ischemia and ischemia progressing to infarction

    International Nuclear Information System (INIS)

    Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) can be reversible or progress to cerebral infarction. In patients with a deterioration clinically diagnosed as DCI, we investigated whether CT perfusion (CTP) can distinguish between reversible ischemia and ischemia progressing to cerebral infarction. From a prospectively collected series of aSAH patients, we included those with DCI, CTP on the day of clinical deterioration, and follow-up imaging. In qualitative CTP analyses (visual assessment), we calculated positive and negative predictive value (PPV and NPV) with 95 % confidence intervals (95%CI) of a perfusion deficit for infarction on follow-up imaging. In quantitative analyses, we compared perfusion values of the least perfused brain tissue between patients with and without infarction by using receiver-operator characteristic curves and calculated a threshold value with PPV and NPV for the perfusion parameter with the highest area under the curve. In qualitative analyses of 33 included patients, 15 of 17 patients (88 %) with and 6 of 16 patients (38 %) without infarction on follow-up imaging had a perfusion deficit during clinical deterioration (p = 0.002). Presence of a perfusion deficit had a PPV of 71 % (95%CI: 48-89 %) and NPV of 83 % (95%CI: 52-98 %) for infarction on follow-up. Quantitative analyses showed that an absolute minimal cerebral blood flow (CBF) threshold of 17.7 mL/100 g/min had a PPV of 63 % (95%CI: 41-81 %) and a NPV of 78 % (95%CI: 40-97 %) for infarction. CTP may differ between patients with DCI who develop infarction and those who do not. For this purpose, qualitative evaluation may perform marginally better than quantitative evaluation. (orig.)

  12. CT perfusion during delayed cerebral ischemia after subarachnoid hemorrhage: distinction between reversible ischemia and ischemia progressing to infarction

    Energy Technology Data Exchange (ETDEWEB)

    Cremers, Charlotte H.P. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, PO Box 85500, Utrecht, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vos, Pieter C. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Schaaf, Irene C. van der; Velthuis, Birgitta K.; Dankbaar, Jan Willem [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vergouwen, Mervyn D.I.; Rinkel, Gabriel J.E. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, PO Box 85500, Utrecht, Utrecht (Netherlands)

    2015-09-15

    Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) can be reversible or progress to cerebral infarction. In patients with a deterioration clinically diagnosed as DCI, we investigated whether CT perfusion (CTP) can distinguish between reversible ischemia and ischemia progressing to cerebral infarction. From a prospectively collected series of aSAH patients, we included those with DCI, CTP on the day of clinical deterioration, and follow-up imaging. In qualitative CTP analyses (visual assessment), we calculated positive and negative predictive value (PPV and NPV) with 95 % confidence intervals (95%CI) of a perfusion deficit for infarction on follow-up imaging. In quantitative analyses, we compared perfusion values of the least perfused brain tissue between patients with and without infarction by using receiver-operator characteristic curves and calculated a threshold value with PPV and NPV for the perfusion parameter with the highest area under the curve. In qualitative analyses of 33 included patients, 15 of 17 patients (88 %) with and 6 of 16 patients (38 %) without infarction on follow-up imaging had a perfusion deficit during clinical deterioration (p = 0.002). Presence of a perfusion deficit had a PPV of 71 % (95%CI: 48-89 %) and NPV of 83 % (95%CI: 52-98 %) for infarction on follow-up. Quantitative analyses showed that an absolute minimal cerebral blood flow (CBF) threshold of 17.7 mL/100 g/min had a PPV of 63 % (95%CI: 41-81 %) and a NPV of 78 % (95%CI: 40-97 %) for infarction. CTP may differ between patients with DCI who develop infarction and those who do not. For this purpose, qualitative evaluation may perform marginally better than quantitative evaluation. (orig.)

  13. Cerebral perfusion studies using Au-195: Investigations into their clinical usefulness and comparisons with the xenon-133 inhalation method

    International Nuclear Information System (INIS)

    Au-195m cerebral perfusion studies in the diagnosis of blood supply disorders of the brain have only recently leaped into currency. Au-195m is not capable of diffusing. This particular property permits first-pass times of vascular transfer to be determined for cerebral tissues that correlate with the degree of cerebral circulation. In the study described here, attempts were made to shed more light on the clinical usefulness of the method. For this purpose, the record sheets of two cohorts of patients were analysed on a retrospective basis. 1. In 23 patients, where the cerebrovascular disorders were strictly confined to the cerebral hemispheres, the blood supply of the brain was examined on the basis of both Au-195m cerebral perfusion studies and the xenon-133 inhalation method. In the evaluation of the findings based on the Au-195m study the investigator was blinded to the neurological manifestations of the disease and the results from other studies. In 82% of the patients the perfusion mapping using Au-195m was consistent with the clinical symptoms. 2. In a second group of patients, the probable results of the Au-195m perfusion study were forecasted on the basis of the medical history, clinical symptoms and preliminary diagnosis and subsequently compared to those actually obtained. Expected and actual results were found to be in agreement for 88% of cases. The results provided evidence of the suitability of Au-195m cerebral perfusion studies to examine the blood suply of the brain. In view of the fact that the examinations and measurements are relatively uncomplicated, this newly developed method is most likely to be used on a broader basis in the future. (orig./MG)

  14. Fatores associados a perfusão cerebral anormal em dependentes de cocaína Factors related to abnormal brain perfusion in cocaine addicts

    OpenAIRE

    Dartiu X da Silveira; Marcelo Fernandes; Antonio Barbieri; Eliseu Labigalini; Evelyn D Silveira

    2001-01-01

    OBJETIVO: Avaliar a relação entre o padrão de uso da cocaína e a perfusão cerebral de dependentes da substância. MÉTODOS: Estudou-se uma amostra de 30 dependentes de cocaína por meio de tomografia computadorizada por emissão de fóton único (single photon emission computed tomography - SPECT) com hexametil-propileno-amina-oxima, marcada com tecnécio 99 m (99 m-Tc-HMPAO), e comparou-se o padrão de perfusão cerebral com o padrão de consumo da droga. RESULTADOS: Dos dependentes, 80% apresentaram ...

  15. Cerebral Critical Closing Pressure During Infusion Tests.

    Science.gov (United States)

    Varsos, Georgios V; Czosnyka, Marek; Smielewski, Peter; Garnett, Matthew R; Liu, Xiuyun; Adams, Hadie; Pickard, John D; Czosnyka, Zofia

    2016-01-01

    We studied possible correlations between cerebral hemodynamic indices based on critical closing pressure (CrCP) and cerebrospinal fluid (CSF) compensatory dynamics, as assessed during lumbar infusion tests. Our data consisted of 34 patients with normal-pressure hydrocephalus who undertook an infusion test, in conjunction with simultaneous transcranial Doppler ultrasonography (TCD) monitoring of blood flow velocity (FV). CrCP was calculated from the monitored signals of ICP, arterial blood pressure (ABP), and FV, whereas vascular wall tension (WT) was estimated as CrCP - ICP. The closing margin (CM) expresses the difference between ABP and CrCP. ICP increased during infusion from 6.67 ± 4.61 to 24.98 ± 10.49 mmHg (mean ± SD; p < 0.001), resulting in CrCP rising by 22.93 % (p < 0.001), with WT decreasing by 11.33 % (p = 0.005) owing to vasodilatation. CM showed a tendency to decrease, albeit not significantly (p = 0.070), because of rising ABP (9.12 %; p = 0.005), and was significantly different from zero for the whole duration of the tests (52.78 ± 22.82 mmHg; p < 0.001). CM at baseline correlated inversely with brain elasticity (R = -0.358; p = 0.038). Neither CrCP nor WT correlated with CSF compensatory parameters. Overall, CrCP increases and WT decreases during infusion tests, whereas CM at baseline pressure may act as a characterizing indicator of the cerebrospinal compensatory reserve. PMID:27165909

  16. Cerebral perfusion reserve in carotid stenosis: Prognostic role in surgical and rheological therapy

    Energy Technology Data Exchange (ETDEWEB)

    Ussov, W.; Shipulin, V.; Shvera, I. [and others

    1994-05-01

    The study was aimed to evaluate the usefulness of the quantitative cerebral perfusion reserve SPECT for the prognosis in patients with critical stenoses of the internal carotid arteries treated surgically or rheotherapeutically. 23 patients with angiographically verified mono (n=12) or bilateral (n=11) stenosis of the internal carotid artery for more than 75% and with recent (>30 days) minor stroke or TIA events in anamnesis were referred for the study. 6 age-matched healthy persons served as controls. In everybody the cerebral perfusion reserve was studied by using of the local cerebral blood volume to cerebral blood flow (rCBV/rCBF, sec) index using a double isotope technique which combined Tl-199 diethyidithiocarbamate (Tl-199-DDC) SPECT with Tc-99m red blood cells (Tc-99m-RBC) SPECT. 12 patients underwent carotid endartherectomy and 11 were treated rheotherapeutically by nonselective plasma substitution (5 times x 400 ml, >1800 nil in total). Patients were studied twicely: before and 10 days after the treatment, and then followed-up neurologically in the course of 1 year. Patients who had regional rCBV/rCBF index increased in the stenosed a.carotis int. - dependent region before treatment (normal value 5.2, sd 0.2 sec) have got it significantly decreased after intervention both in surgical group (from 7.1, sd 0.4 sec, down to 5.3, sd 0.3 sec, p<0.01 n=7) and in rheotherapeutical one (from 7.3, sd 0.5 sec, to 5.9, sd 0.4 sec, p<0.02 n=8). In everybody who expressed the rCBV/rCBF decreased below 5.6 sec after intervention there were no cerebrovascular ischemic events observed in the course of 12 months after carotid surgery and during 5 months in patients treated by plasmapheresis. We conclude that rCBV/rCBF SPECT index gives an independent prognostic information useful for both rheologic and surgical treatment of cerebrovascular disease; and that plasmapheresis suppress the short-term rise of cerebral ischemic events, which effect is predictable by SPECT.

  17. PERFUSION PRESSURE AND RENAL BLOOD FLOW: THEIR RELATIONSHIP AND DIFFERENCES

    Directory of Open Access Journals (Sweden)

    Carlos G. Musso, MD. PhD.1,2, Manuel Vilas, MD.

    2014-05-01

    Full Text Available The concepts of renal perfusion pressure (RPP and renal blood flow (RBF are usually confused, but although they are intimately related, they are not strictly the same. RPP originates from the minute cardiac volume and is, therefore, the cause of RBF, which generates glomerular filtration and as a consequence, also induces the urinary flow. On the other hand, whereas RPP can be subject to fluctuations, the same happens to RBF though at a much lower level due to the existence of physiological mechanisms, such as self-regulation of the flow and tubule-glomerular feed-back. We conclude that there is a dependence of the RBF in relation with RPP, with the former acting as the final responsible of the glomerular filtration.

  18. Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study

    International Nuclear Information System (INIS)

    Validation of the feasibility and efficacy of volume perfusion computed tomography (VPCT) in the preoperative assessment of cerebral gliomas by applying a 128-slice CT covering the entire tumour. Forty-six patients (25 men, 21 women; mean age 52.8 years) with cerebral gliomas were evaluated with VPCT. Two readers independently evaluated VPCT data, drawing volumes of interest (VOIs) around the tumour according to maximum intensity projection volumes, which were mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability (Ktrans) perfusion datasets. As control, a second VOI was placed in the contralateral healthy cortex. Correlation among perfusion parameters, tumour grade, hemisphere and VOIs was assessed. The diagnostic power of perfusion parameters was analysed by receiver operating characteristics curve analyses. VPCT was feasible in the assessment of the entire tumour extent. Mean values of Ktrans, CBV, CBF in high-grade gliomas were significantly higher compared with low-grade (p < 0.01). Ktrans demonstrated the highest diagnostic (97% sensitivity), positive (100%) and negative (94%) prognostic values. VPCT was feasible in all subjects. All areas of different perfusion characteristics are depicted and quantified in colour-coded 3D maps. The derived parameters correlate well with tumour histopathology, differentiating low- from high-grade gliomas. (orig.)

  19. Brain volume perfusion CT performed with 128-detector row CT system in patients with cerebral gliomas: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Xyda, Argyro [University Hospital of Goettingen, Department of Neuroradiology, Georg-August University, Goettingen (Germany); University Hospital of Heraklion, Department of Radiology, Crete (Greece); Haberland, Ulrike; Klotz, Ernst [Computed Tomography, Siemens AG Healthcare Sector, Forchheim (Germany); Bock, Hans Christoph [University Hospital of Goettingen, Department of Neurosurgery, Georg-August University, Goettingen (Germany); Jung, Klaus [University Hospital of Goettingen, Department of Medical Statistics, Georg-August University, Goettingen (Germany); Knauth, Michael; Schramm, Ramona; Psychogios, Marios Nikos; Schramm, Peter [University Hospital of Goettingen, Department of Neuroradiology, Georg-August University, Goettingen (Germany); Erb, Gunter [Bracco Imaging Deutschland GmbH, Konstanz (Germany)

    2011-09-15

    Validation of the feasibility and efficacy of volume perfusion computed tomography (VPCT) in the preoperative assessment of cerebral gliomas by applying a 128-slice CT covering the entire tumour. Forty-six patients (25 men, 21 women; mean age 52.8 years) with cerebral gliomas were evaluated with VPCT. Two readers independently evaluated VPCT data, drawing volumes of interest (VOIs) around the tumour according to maximum intensity projection volumes, which were mapped automatically onto the cerebral blood volume (CBV), flow (CBF) and permeability (Ktrans) perfusion datasets. As control, a second VOI was placed in the contralateral healthy cortex. Correlation among perfusion parameters, tumour grade, hemisphere and VOIs was assessed. The diagnostic power of perfusion parameters was analysed by receiver operating characteristics curve analyses. VPCT was feasible in the assessment of the entire tumour extent. Mean values of Ktrans, CBV, CBF in high-grade gliomas were significantly higher compared with low-grade (p < 0.01). Ktrans demonstrated the highest diagnostic (97% sensitivity), positive (100%) and negative (94%) prognostic values. VPCT was feasible in all subjects. All areas of different perfusion characteristics are depicted and quantified in colour-coded 3D maps. The derived parameters correlate well with tumour histopathology, differentiating low- from high-grade gliomas. (orig.)

  20. The preliminary study of CT cerebral perfusion imaging on the brain injury of the high + Gx in Rhesus

    International Nuclear Information System (INIS)

    Objective: To exp lore the diagnostic value of CT cerebral perfusion imaging on the brain injury of the high + Gx in Rhesus. Methods: Seven healthy male adult Rhesus were randomly divided into control group and + 15 Gx group. The + 15 Gx group underwent parabolic G curve in animal centrifuge. The animals were all examined by CT cerebral perfusion before + Gx exposure, 2 h, 24 h, and 1 week after + Gx exposure. The results were compared with pathologic examination. Results: 2 h and 24 h after + 15 Gx exposure, brain ischemia was showed on CT cerebral perfusion imaging. After 1 week, the brain ischemia was almost recovered to normal. Mild ischemic atrophy was observed in pyramidal neurons in cerebral cortex by light microscopy. Electron microscopic observation showed chromatin marginating and mitochondria cristae blurring in pyramidal cells after + Gx overload. Conclusion: High G from simulating spaceship emergency return can cause ischemic injuries of the brain in Rhesus, and CT brain perfusion imaging can provide valuable diagnostic information. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-15

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

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

    International Nuclear Information System (INIS)

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

  3. Increased intrathoracic pressure affects cerebral oxygenation following cardiac surgery

    DEFF Research Database (Denmark)

    Pedersen, Lars M; Nielsen, Jonas; Østergaard, Morten; Nygård, Eigil; Nielsen, Henning

    2012-01-01

    Cerebral oximetry reflects circulatory stability during surgery. We evaluated whether frontal lobe oxygenation is influenced by a transient increase in intrathoracic pressure as induced by a lung recruitment manoeuvre....

  4. Different CT perfusion algorithms in the detection of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Cremers, Charlotte H.P. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Room G03.232, Brain Center Rudolf Magnus Department of Neurology and Neurosurgery, PO Box 85500, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Dankbaar, Jan Willem; Bennink, Edwin; Velthuis, Birgitta K.; Schaaf, Irene C. van der [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Vergouwen, Mervyn D.I.; Rinkel, Gabriel J.E. [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Room G03.232, Brain Center Rudolf Magnus Department of Neurology and Neurosurgery, PO Box 85500, Utrecht (Netherlands); Vos, Pieter C. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

    2015-05-01

    Tracer delay-sensitive perfusion algorithms in CT perfusion (CTP) result in an overestimation of the extent of ischemia in thromboembolic stroke. In diagnosing delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH), delayed arrival of contrast due to vasospasm may also overestimate the extent of ischemia. We investigated the diagnostic accuracy of tracer delay-sensitive and tracer delay-insensitive algorithms for detecting DCI. From a prospectively collected series of aSAH patients admitted between 2007-2011, we included patients with any clinical deterioration other than rebleeding within 21 days after SAH who underwent NCCT/CTP/CTA imaging. Causes of clinical deterioration were categorized into DCI and no DCI. CTP maps were calculated with tracer delay-sensitive and tracer delay-insensitive algorithms and were visually assessed for the presence of perfusion deficits by two independent observers with different levels of experience. The diagnostic value of both algorithms was calculated for both observers. Seventy-one patients were included. For the experienced observer, the positive predictive values (PPVs) were 0.67 for the delay-sensitive and 0.66 for the delay-insensitive algorithm, and the negative predictive values (NPVs) were 0.73 and 0.74. For the less experienced observer, PPVs were 0.60 for both algorithms, and NPVs were 0.66 for the delay-sensitive and 0.63 for the delay-insensitive algorithm. Test characteristics are comparable for tracer delay-sensitive and tracer delay-insensitive algorithms for the visual assessment of CTP in diagnosing DCI. This indicates that both algorithms can be used for this purpose. (orig.)

  5. Different CT perfusion algorithms in the detection of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    Tracer delay-sensitive perfusion algorithms in CT perfusion (CTP) result in an overestimation of the extent of ischemia in thromboembolic stroke. In diagnosing delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH), delayed arrival of contrast due to vasospasm may also overestimate the extent of ischemia. We investigated the diagnostic accuracy of tracer delay-sensitive and tracer delay-insensitive algorithms for detecting DCI. From a prospectively collected series of aSAH patients admitted between 2007-2011, we included patients with any clinical deterioration other than rebleeding within 21 days after SAH who underwent NCCT/CTP/CTA imaging. Causes of clinical deterioration were categorized into DCI and no DCI. CTP maps were calculated with tracer delay-sensitive and tracer delay-insensitive algorithms and were visually assessed for the presence of perfusion deficits by two independent observers with different levels of experience. The diagnostic value of both algorithms was calculated for both observers. Seventy-one patients were included. For the experienced observer, the positive predictive values (PPVs) were 0.67 for the delay-sensitive and 0.66 for the delay-insensitive algorithm, and the negative predictive values (NPVs) were 0.73 and 0.74. For the less experienced observer, PPVs were 0.60 for both algorithms, and NPVs were 0.66 for the delay-sensitive and 0.63 for the delay-insensitive algorithm. Test characteristics are comparable for tracer delay-sensitive and tracer delay-insensitive algorithms for the visual assessment of CTP in diagnosing DCI. This indicates that both algorithms can be used for this purpose. (orig.)

  6. Assessment of Hyperperfusion by Brain Perfusion SPECT in Transient Neurological Deterioration after Superficial Temporal Artery-Middle Cerebral Artery Anastomosis Surgery

    International Nuclear Information System (INIS)

    Transient neurological deterioration (TND) is one of the complications after extracranial-intracranial bypass surgery, and it has been assumed to be caused by postoperative transient hyperperfusion. This study was performed to evaluate the relationship between TND and preoperative and postoperative cerebral perfusion status on brain perfusion SPECT following superficial temporal artery.middle cerebral artery (STA-MCA) anastomosis surgery. A total of 60 STA-MCA anastomosis surgeries of 56 patients (mean age: 50±16 yrs; M:F=29:27; atherosclerotic disease: 33, moyamoya disease: 27) which were done between September 2003 and July 2006 were enrolled. The resting cerebral perfusion and cerebral vascular reserve (CVR) after acetazolamide challenge were measured before and 10 days after surgery using 99mTc-ethylcysteinate dimer (ECD) SPECT. Moreover, the cerebral perfusion was measured on the third postoperative day. With the use of the statistical parametric mapping and probabilistic brain atlas, the counts for the middle cerebral artery (MCA) territory were calculated for each image, and statistical analyses were performed. In 6 of 60 cases (10%), TND occurred after surgery. In all patients, the preoperative cerebral perfusion of affected MCA territory was significantly lower than that of contralateral side (p=0.002). The cerebral perfusion on the third and tenth day after surgery was significantly higher than preoperative cerebral perfusion (p=0.001, p=0.02). In TND patients, basal cerebral perfusion and CVR on preoperative SPECT were significantly lower than those of non-TND patients (p=0.01, p=0.05). Further, the increases in cerebral perfusion on the third day after surgery were significant higher than those in other patients (p=0.008). In patients with TND, the cerebral perfusion ratio of affected side to contralateral side on third postoperative day was significantly higher than that of other patients (p=0.002). However, there was no significant difference of the

  7. Correspondence of CT perfusion imaging to pathological manifestations in rabbit models of hyperacute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Mingwu Lou; Yi Fan; Lizhong Jia; Weidong Hu; Yan Teng; Guangfu Yang

    2007-01-01

    BACKGROUND: Could the infarction be diagnosed quickly and accurately at the acute stage by CT perfusion imaging (CTPI) technology? Whether the images of CTPI will correspond with the pathological changes or not? All the questions need to be solved by experimental and clinical studies.OBJECTIVE: To reveal the rules of perfusion map changes and guide the early diagnosis of hyperacute cerebral infarction by analyzing the correlation of CTPI with pathological manifestations for hyperacute cerebral infarction.DESIGN: A randomized controlled animal experiment.SETTING: Experimental Center of Medical Radiology, Longgang Central Hospital of Shenzhen City.MATERIALS: Forty-two adult New Zealand rabbits of (2.6±0.5) kg, either male or female, were randomly divided into experimental group (n =36) and control group (n =6). Six rabbits in the experimental group were observed after ischemia for 0.5, 1, 2, 3, 4 and 6 hours respectively, and 1 rabbit in the control group was observed at each corresponding time point.METHODS: The experiments were carded out in the Experimental Center of Medical Radiology,Longgang Central Hospital of Shenzhen City from March 2003 to July 2004, Rabbit models of cerebral scanned at 0.5, 1, 2, 3, 4 and 6 hours after ischemia respectively. The dynamic CT scan slice was 13 mm from the anterior edge of the frontal cortex, and six fake color functional images were obtained, including cerebral blood flow map (CBF map), cerebral blood volume map (CBV map), peak to enhancement map (PE map),flow without vessels map, time to peak map (TP map), time to start map (TS map). The manifestations and (ROI) were drawn separately on the CBF map, CBV map, TP map and TS map. The blood flow parameters of focal and contralateral cerebral tissues could be obtained to calculate relative cerebral blood flow (rCBF,rCBF=focal CBF/contralateral CBF), relative cerebral blood volume (rCBV, rCBV= focal CBV/contralateral CBV), a relative time to peak (rTP, rTP= focal TP

  8. Perfusion MR imaging and proton MR spectroscopic imaging in differentiating necrotizing cerebritis from glioblastoma multiforme.

    Science.gov (United States)

    Pivawer, Gabriel; Law, Meng; Zagzag, David

    2007-02-01

    We describe a lesion with the magnetic resonance imaging (MRI) characteristics of a glioblastoma mutiforme and demonstrate how perfusion MRI and proton MR spectroscopic imaging can be used to differentiate necrotizing cerebritis from what appeared to be a high-grade glioma. A 43-year-old woman presented to her physician complaining of progressive visual disturbance and headache for several weeks. Conventional MRI demonstrated a parietal peripherally enhancing mass with central necrosis and moderate to severe surrounding T2 hyperintensity, suggesting an infiltrating high-grade glioma. However, advanced imaging, including dynamic susceptibility contrast MRI (DSC MRI) and magnetic resonance spectroscopic imaging (MRSI), suggested a nonneoplastic lesion. The DSC MRI data demonstrated no hyperperfusion within the lesion and surrounding T2 signal abnormality, and the MRSI data showed overall decrease in metabolites in this region, except for lactate. Because of the aggressive appearance to the lesion and the patients' worsening symptoms, a biopsy was performed. The pathologic diagnosis was necrotizing cerebritis. After the commencement of steroid therapy, imaging findings and patient symptoms improved. This report will review the utility of advanced imaging for differentiating inflammatory from neoplastic appearing lesions on conventional imaging. PMID:17275620

  9. Carotid artery disease and low cerebral perfusion pressure

    DEFF Research Database (Denmark)

    Schroeder, T; Utzon, N P; Aabech, J;

    1990-01-01

    with those of a control group of a further 49 patients selected from the remaining patients operated on over the same period. The two groups were compared for short- and long-term outcome of surgery. We were unable to delineate a symptomatic neurological profile that identified patients with low......-term results were equal in the two groups with an annual stroke risk of 3%....

  10. Comparison of Two Algorithms for Analysis of Perfusion Computed Tomography Data for Evaluation of Cerebral Microcirculation in Chronic Subdural Hematoma.

    Science.gov (United States)

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Yuriev, Michail; Agarkova, Darya; Trofimova, Svetlana; Bragin, Denis E

    2016-01-01

    The aim of this work was comparison of two algorithms of perfusion computed tomography (PCT) data analysis for evaluation of cerebral microcirculation in the perifocal zone of chronic subdural hematoma (CSDH). Twenty patients with CSDH after polytrauma were included in the study. The same PCT data were assessed quantitatively in cortical brain region beneath the CSDH (zone 1), and in the corresponding contralateral brain hemisphere (zone 2) without and with the use of perfusion calculation mode excluding vascular pixel 'Remote Vessels' (RV); 1st and 2nd analysis method, respectively. Comparison with normal values for perfusion indices in the zone 1 in the 1st analysis method showed a significant (p < 0.01) increase in CBV and CBF, and no significant increase in MTT and TTP. Use of the RV mode (2nd analysis method) showed no statistically reliable change of perfusion parameters in the microcirculatory blood flow of the 2nd zone. Maintenance of microcirculatory blood flow perfusion reflects the preservation of cerebral blood flow autoregulation in patients with CSDH. PMID:27526170

  11. Cerebral hemodynamics in human acute ischemic stroke: a study with diffusion- and perfusion-weighted magnetic resonance imaging and SPECT.

    Science.gov (United States)

    Liu, Y; Karonen, J O; Vanninen, R L; Ostergaard, L; Roivainen, R; Nuutinen, J; Perkiö, J; Könönen, M; Hämäläinen, A; Vanninen, E J; Soimakallio, S; Kuikka, J T; Aronen, H J

    2000-06-01

    Nineteen patients with acute ischemic stroke (<24 hours) underwent diffusion-weighted and perfusion-weighted (PWI) magnetic resonance imaging at the acute stage and 1 week later. Eleven patients also underwent technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (SPECT) at the acute stage. Relative (ischemic vs. contralateral control) cerebral blood flow (relCBF), relative cerebral blood volume, and relative mean transit time were measured in the ischemic core, in the area of infarct growth, and in the eventually viable ischemic tissue on PWI maps. The relCBF was also measured from SPECT. There was a curvilinear relationship between the relCBF measured from PWI and SPECT (r = 0.854; P < 0.001). The tissue proceeding to infarction during the follow-up had significantly lower initial CBF and cerebral blood volume values on PWI maps (P < 0.001) than the eventually viable ischemic tissue had. The best value for discriminating the area of infarct growth from the eventually viable ischemic tissue was 48% for PWI relCBF and 87% for PWI relative cerebral blood volume. Combined diffusion and perfusion-weighted imaging enables one to detect hemodynamically different subregions inside the initial perfusion abnormality. Tissue survival may be different in these subregions and may be predicted. PMID:10894174

  12. Prediction of cerebral hyperperfusion syndrome after carotid artery stenting by CT perfusion imaging with acetazolamide challenge

    Energy Technology Data Exchange (ETDEWEB)

    Yoshie, Tomohide; Ueda, Toshihiro; Takada, Tatsuro; Nogoshi, Shinji; Fukano, Takayuki [St. Marianna University Toyoko Hospital, Department of Strokology, Stroke Center, Kawasaki (Japan); Hasegawa, Yasuhiro [St. Marianna University School of Medicine, Department of Internal Medicine, Division of Neurology, Kawasaki (Japan)

    2016-03-15

    Cerebral hyperperfusion syndrome (HPS) is an uncommon but serious complication of carotid artery stenting (CAS). The purpose of this study was to investigate the efficacy of CT perfusion imaging (CTP) with acetazolamide challenge to identify patients at risk for HPS after CAS. We retrospectively analyzed 113 patients who underwent CTP with rest and acetazolamide challenge before CAS. CTP maps were assessed for absolute and relative cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and change of each parameter before and after acetazolamide challenge. Patients were divided into two groups according to the HPS after the CAS. Receiver-operating characteristic (ROC) curve analysis was performed to determine the most accurate CTP parameter for the prediction of HPS. Nine of 113 patients had HPS. There were significant differences for absolute and relative values of resting CBF (p = 0.001 and p = 0.026), resting MTT (p < 0.001 and p = 0.004), post-acetazolamide CBF (p < 0.001 and p = 0.001), post-acetazolamide MTT (p < 0.001 and p = 0.002), and %changes of CBF (p = 0.009) between the HPS and non-HPS groups. ROC curve analysis showed that the CTP parameters with the maximal area under the receiver-operating characteristic curve (AUC) for HPS was the absolute value of post-acetazolamide MTT (AUC 0.909) and the absolute value of resting MTT (AUC 0.896). Pretreatment CTP with acetazolamide challenge could identify patients at risk for HPS after CAS. Although the CTP parameter that most accurately identified patients at risk for HPS was the absolute value of post-acetazolamide MTT, resting MTT was sufficiently accurate. (orig.)

  13. Skin Perfusion Pressure Is a Prognostic Factor in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Shingo Hatakeyama

    2012-01-01

    Full Text Available Peripheral arterial disease (PAD is common in hemodialysis patients and predicts a poor prognosis. We conducted a prospective cohort study to identify risk factors for PAD including skin perfusion pressure (SPP in hemodialysis patients. The cohort included 373 hemodialysis patients among 548 patients who received hemodialysis at Oyokyo Kidney Research Institute, Hirosaki, Japan from August 2008 to December 2010. The endpoints were lower limb survival (peripheral angioplasty or amputation events and overall survival of 2 years. Our results showed that <70 mmHg SPP was a poor prognosis for the lower limb survival and overall survival. We also identified age, history of cardiovascular disease, presence of diabetes mellitus, smoking history, and SPP < 70 mmHg as independent risk factors for lower limb survival and overall survival. Then, we constructed risk criteria using the significantly independent risk factors. We can clearly stratify lower limb survival and overall survival of the hemodialysis patients into 3 groups. Although the observation period is short, we conclude that SPP value has the potential to be a risk factor that predicts both lower limb survival and the prognosis of hemodialysis patients.

  14. Acetazolamide tomoscintigraphic study of the effect on cerebral blood perfusion using 123I isopropyliodoamphetamine (IAMP 123I). Preliminary results

    International Nuclear Information System (INIS)

    The effect of Acetazolamide (Diamox) on cerebral blood perfusion has been studied in ten patients with cerebral ischemia. Previously, the dose and time effects was tested in two independent groups of male Wistar rats. The cerebral blood perfusion was estimated in man by the cerebral distribution of Isopropyliodoamphetamine 123I (IAMP 123I) visualised with conventional emission tomography. The study involved two identical examinations, the second one followed an injection of 1 g of Diamox. The biodistribution of IAMP 123I was studied in rats without or after different doses of Diamox by counting of target organs. In animals, the pulmonary activity curve versus the dose showed a maximum for 100 mg/kg as the cerebral activity curve increased proportional to the dose. The study of time effect indicated that the best conditions for cerebral imaging by IAMP123I seems to take place twenty minutes after the injection of Diamox. In man, the results obtained after Diamox confirmed the known effect of decreasing of vascular resistance, especially in brain. The total cerebral activity in IAMP123I was increased in all the patients. In six patients of the ten, the activity of the ischemic region was lower than expected because of the high uptake of the controlateral hemisphere. This phenomenon may increase the sensitivity of detecting lightly hypoperfused cerebral regions. In some other patients, a high activity of the ischemic zone seems to proove an early regulation of the regional blood flow and may be an element of good pronostic. Making an Acetazolamide injection before a tomoscintigraphic examination of the brain with IAMP123I seems to provide conventional imaging with sensitivity and pronostic value

  15. Absolute quantification of cerebral blood flow in neurologically normal volunteers: dynamic-susceptibility contrast MRI-perfusion compared with computed tomography (CT)-perfusion.

    Science.gov (United States)

    Ziegelitz, Doerthe; Starck, Göran; Mikkelsen, Irene K; Tullberg, Mats; Edsbagge, Mikael; Wikkelsö, Carsten; Forssell-Aronson, Eva; Holtås, Stig; Knutsson, Linda

    2009-07-01

    To improve the reproducibility of arterial input function (AIF) registration and absolute cerebral blood flow (CBF) quantification in dynamic-susceptibility MRI-perfusion (MRP) at 1.5T, we rescaled the AIF by use of a venous output function (VOF). We compared CBF estimates of 20 healthy, elderly volunteers, obtained by computed tomography (CT)-perfusion (CTP) and MRP on two consecutive days. MRP, calculated without the AIF correction, did not result in any significant correlation with CTP. The rescaled MRP showed fair to moderate correlation with CTP for the central gray matter (GM) and the whole brain. Our results indicate that the method used for correction of partial volume effects (PVEs) improves MRP experiments by reducing AIF-introduced variance at 1.5T. PMID:19253361

  16. Monitoring cerebral oxygen saturation during cardiopulmonary bypass using near-infrared spectroscopy: the relationships with body temperature and perfusion rate

    Science.gov (United States)

    Teng, Yichao; Ding, HaiShu; Gong, Qingcheng; Jia, Zaishen; Huang, Lan

    2006-03-01

    During cardiopulmonary bypass (CPB) because of weak arterial pulsation, near-IR spectroscopy (NIRS) is almost the only available method to monitor cerebral oxygenation noninvasively. Our group develops a NIRS oximeter to monitor regional cerebral oxygenation especially its oxygen saturation (rScO2). To achieve optimal coupling between the sensor and human brain, the distances between the light source and the detectors on it are properly chosen. The oximeter is calibrated by blood gas analysis, and the results indicate that its algorithm is little influenced by either background absorption or overlying tissue. We used it to measure the rScO2 of 15 patients during CPB. It is shown that rScO2 is negatively correlated with body temperature and positively with perfusion rate. There are two critical stages during CPB when rScO2 might be relatively low: one is the low-perfusion-rate stage, the other is the early rewarming stage. During cooling, the changes of total hemoglobin concentration (CtHb) compared with its original value is also monitored. It is shown that CtHb decreases to a small extent, which may mainly reflect cerebral vasoconstriction induced by cooling. All these results indicate that NIRS can be used to monitor cerebral oxygenation to protect cerebral tissue during CPB.

  17. Usefulness of CT perfusion in the selection of patients with hyperacute cerebral infarction for intravenous t-PA treatment

    International Nuclear Information System (INIS)

    We investigated the usefulness of CT perfusion (CT-P) for assessing whether or not intravenous t-PA treatment is indicated for hyperacute cerebral infarction within 3 hours after onset. Between April 2007 and March 2008, 40 cerebral infarction patients were brought to our hospital within 3 hours of occurrence (28 men, 12 women; average age, 71 years; average time from onset to hospital admission, 93 min). Among these 40 patients, 14 patients who underwent brain CT, brain MRI (diffusion weighted images (DWI)/MR angiography (MRA)), and CT-P were investigated. The clinical types included 7 cardioembolic infarction (CE) cases, 6 atherothrombotic infarction (AT) cases, and 1 lacunar infarction (LC) case. Among the 14 patients who underwent CT-P, no perfusion abnormalities were noted in 6 of 8 patients with an National Institute of Health Stroke Scale (NIHSS) score of 11 points or less at the time of hospital arrival. Of these 6 patients, 1 had LC, 3 had CE, and 2 had AT. In 2 patients (CE: M2 occlusion; AT: M1 stenosis), an area of abnormal perfusion was recognized, but no difference was observed in the high signal area on DWI. In all patients with an NIHSS score of 15 points or more, diffusion-CT perfusion mismatch (DPM) was seen. In addition, main artery lesions were found on MRA in 5 of 6 patients with DPM. t-PA was given to 10 of the 14 patients. In the hyperacute phase of cerebral infarction within 3 hours of occurrence, mild cases and those without main cerebral artery lesions have little need for CT-P. In moderate and severe cases, CT-P appears to be effective for evaluating DPM. (author)

  18. Improving Cerebral Blood Flow Quantification for Arterial Spin Labeled Perfusion MRI by Removing Residual Motion Artifacts and Global Signal Fluctuations

    OpenAIRE

    Wang, Ze

    2012-01-01

    Denoising is critical to improving the quality and stability of cerebral blood flow (CBF) quantification in arterial spin labeled (ASL) perfusion MRI due to the intrinsic low signal-to-noise-ratio (SNR) of ASL data. Previous studies have been focused on reducing the spatial or temporal noise using standard filtering techniques, and less attention has been paid to two global nuisance effects, the residual motion artifacts and the global signal fluctuations. Since both nuisances affect the whol...

  19. Volumetric Cerebral Perfusion Imaging in Healthy Adults: Regional Distribution, Laterality, and Repeatability of Pulsed Continuous Arterial Spin Labeling (PCASL)

    OpenAIRE

    Pfefferbaum, Adolf; Chanraud, Sandra; Pitel, Anne-Lise; Shankaranarayanan, Ajit; Alsop, David C.; Rohlfing, Torsten; Edith V. Sullivan

    2010-01-01

    The regional distribution, laterality, and reliability of volumetric pulsed continuous arterial spin labeling (PCASL) measurements of cerebral blood flow (CBF) in cortical, subcortical, and cerebellar regions were determined in 10 normal volunteers studied on two occasions separated by 3 to 7 days. Regional CBF, normalized for global perfusion, was highly reliable when measured on separate days. Several regions showed significant lateral asymmetry; notably, in frontal regions CBF was greater ...

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

    International Nuclear Information System (INIS)

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

  1. SPECT imaging of GABAA/benzodiazepine receptors and cerebral perfusion in mild cognitive impairment

    International Nuclear Information System (INIS)

    The involvement of neocortical and limbic GABAA/benzodiazepine (BZD) receptors in Alzheimer's disease (AD) is controversial and mainly reported in advanced stages. The status of these receptors in the very early stages of AD is unclear and has not been explored in vivo. Our aims were to investigate in vivo the integrity of cerebral cortical GABAA/BZD receptors in subjects with amnestic mild cognitive impairment (MCI) and to compare possible receptor changes to those in cerebral perfusion. [123I]Iomazenil and [99mTc]HMPAO SPECT images were acquired in 16 patients with amnestic MCI and in 14 normal elderly control subjects (only [123I]iomazenil imaging in 5, only [99mTc]HMPAO imaging in 4, and both [123I]iomazenil and [99mTc]HMPAO imaging in 5). Region of interest (ROI) analysis and voxel-based analysis were performed with cerebellar normalization. Neither ROI analysis nor voxel-based analysis showed significant [123I]iomazenil binding changes in MCI patients compared to control subjects, either as a whole group or when considering only those patients with MCI that converted to AD within 2 years of clinical follow-up. In contrast, the ROI analysis revealed significant hypoperfusion of the precuneus and posterior cingulate cortex in the whole group of MCI patients and in MCI converters as compared to control subjects. Voxel-based analysis showed similar results. These results indicate that in the very early stages of AD, neocortical and limbic neurons/synapses expressing GABAA/BZD receptors are essentially preserved. They suggest that in MCI patients functional changes precede neuronal/synaptic loss in neocortical posterior regions and that [99mTc]HMPAO rCBF imaging is more sensitive than [123I]iomazenil GABAA/BZD receptor imaging in detecting prodromal AD. (orig.)

  2. Clinical Neuroimaging of cerebral ischemia

    International Nuclear Information System (INIS)

    Notice points in clinical imaging of cerebral ischemia are reviewed. When cerebral blood flow is determined in acute stage of cerebral embolism (cerebral blood flow SPECT), it is important to find area of ischemic core and ischemic penumbra. When large cortex area is assigned to ischemic penumbra, thrombolytic therapy is positively adapted, but cautious correspondence is necessary when ischemic core is recognized. DWI is superior in the detection of area equivalent to ischemic core of early stage, but, in imaging of area equivalent to ischemic penumbra, perfusion image or distribution image of cerebral blood volume (CBV) by MRI need to be combined. Luxury perfusion detected by cerebral blood flow SPECT in the cases of acute cerebral embolism suggests vascular recanalization, but a comparison with CT/MRI and continuous assessment of cerebral circulation dynamics were necessary in order to predict brain tissue disease (metabolic abnormality). In hemodynamic cerebral ischemia, it is important to find stage 2 equivalent to misery perfusion by quantification of cerebral blood flow SPECT. Degree of diaschisis can indicate seriousness of brain dysfunction for lacuna infarct. Because cerebral circulation reserve ability (perfusion pressure) is normal in all areas of the low cerebral blood flow by diaschisis mechanism, their areas are easily distinguished from those of hemodynamic cerebral ischemia. (K.H.)

  3. Quantitative cerebral perfusion assessment using microscope-integrated analysis of intraoperative indocyanine green fluorescence angiography versus positron emission tomography in superficial temporal artery to middle cerebral artery anastomosis

    Directory of Open Access Journals (Sweden)

    Shinya Kobayashi

    2014-01-01

    Full Text Available Background: Intraoperative qualitative indocyanine green (ICG angiography has been used in cerebrovascular surgery. Hyperperfusion may lead to neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA anastomosis. The purpose of this study is to quantitatively evaluate intraoperative cerebral perfusion using microscope-integrated dynamic ICG fluorescence analysis, and to assess whether this value predicts hyperperfusion syndrome (HPS after STA-MCA anastomosis. Methods: Ten patients undergoing STA-MCA anastomosis due to unilateral major cerebral artery occlusive disease were included. Ten patients with normal cerebral perfusion served as controls. The ICG transit curve from six regions of interest (ROIs on the cortex, corresponding to ROIs on positron emission tomography (PET study, was recorded. Maximum intensity (I MAX , cerebral blood flow index (CBFi, rise time (RT, and time to peak (TTP were evaluated. Results: RT/TTP, but not I MAX or CBFi, could differentiate between control and study subjects. RT/TTP correlated (|r| = 0.534-0.807; P < 0.01 with mean transit time (MTT/MTT ratio in the ipsilateral to contralateral hemisphere by PET study. Bland-Altman analysis showed a wide limit of agreement between RT and MTT and between TTP and MTT. The ratio of RT before and after bypass procedures was significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.60 ± 0.032 and 0.80 ± 0.056, respectively; P = 0.017. The ratio of TTP was also significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.64 ± 0.081 and 0.85 ± 0.095, respectively; P = 0.017. Conclusions: Time-dependent intraoperative parameters from the ICG transit curve provide quantitative information regarding cerebral circulation time with quality and utility comparable to information obtained by PET. These parameters may help predict the occurrence of postoperative

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

    International Nuclear Information System (INIS)

    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)

  5. Perfusion functional MRI reveals cerebral blood flow pattern under psychological stress

    Science.gov (United States)

    Wang, Jiongjiong; Rao, Hengyi; Wetmore, Gabriel S.; Furlan, Patricia M.; Korczykowski, Marc; Dinges, David F.; Detre, John A.

    2005-12-01

    Despite the prevalence of stress in everyday life and its impact on happiness, health, and cognition, little is known about the neural substrate of the experience of everyday stress in humans. We use a quantitative and noninvasive neuroimaging technique, arterial spin-labeling perfusion MRI, to measure cerebral blood flow (CBF) changes associated with mild to moderate stress induced by a mental arithmetic task with performance monitoring. Elicitation of stress was verified by self-report of stress and emotional state and measures of heart rate and salivary-cortisol level. The change in CBF induced by the stress task was positively correlated with subjective stress rating in the ventral right prefrontal cortex (RPFC) and left insula/putamen area. The ventral RPFC along with right insula/putamen and anterior cingulate showed sustained activation after task completion in subjects reporting a high stress level during arithmetic tasks. Additionally, variations of baseline CBF in the ventral RPFC and right orbitofrontal cortex were found to correlate with changes in salivary-cortisol level and heart rate caused by undergoing stress tasks. We further demonstrated that the observed right prefrontal activation could not be attributed to increased cognitive demand accompanying stress tasks and extended beyond neural pathways associated with negative emotions. Our results provide neuroimaging evidence that psychological stress induces negative emotion and vigilance and that the ventral RPFC plays a key role in the central stress response. anterior cingulate cortex | arterial spin labeling | right prefrontal cortex

  6. Cerebral perfusion and automated individual analysis using SPECT among an obsessive-compulsive population

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    Euclides Timóteo da Rocha

    2011-01-01

    Full Text Available OBJECTIVE: To make individual assessments using automated quantification methodology in order to screen for perfusion abnormalities in cerebral SPECT examinations among a sample of subjects with OCD. METHODS: Statistical parametric mapping (SPM was used to compare 26 brain SPECT images from patients with OCD individually with an image bank of 32 normal subjects, using the statistical threshold of p < 0.05 (corrected for multiple comparisons at the level of individual voxels or clusters. The maps were analyzed, and regions presenting voxels that remained above this threshold were sought. RESULTS: Six patients from a sample of 26 OCD images showed abnormalities at cluster or voxel level, considering the criteria described above, which represented 23.07%. However, seven images from the normal group of 32 were also indicated as cases of perfusional abnormality, representing 21.8% of the sample. CONCLUSION: The automated quantification method was not considered to be a useful tool for clinical practice, for analyses complementary to visual inspection.

  7. Perfusion MR imaging in patients with acute cerebral infarction: comparison with T2-weighted and diffusion-weighted MR imaging

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    Jae, Hwan Jun; Chang, Kee Hyun; Song, In Chan; Park, Sun Won; Kim, Yoon Hee; Choi, Joon Il; Han, Moon Hee [College of Medicine, Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Kim, Hong Dae [Kang Nam Sacred Heart Hospital, Seoul (Korea, Republic of); Kim, Hyung Seok [Cheju Medical Center, Cheju (Korea, Republic of)

    2000-07-01

    To evaluate the clinical usefulness of perfusion MR imaging by comparing with T2-weighted and diffusion weighted MR imaging in patients with acute cerebral ischemic infarction. Conventional, diffusion weighted, and perfusion MR images were obtained within one week of clinical onset in 14 cases of acute ischemic infarction. For perfusion MRI, the gradient-echo EPI technique after IV bolus injection of 15 cc of contrast media was used. Four kinds of perfusion MR images (rCBV, rCBF, mean transit time (MTT), time to peak concentration (TTP)) were generated by home-made software from the raw data. T2-weighted, diffusion-weighted, and perfusion images of each patient were retrospectively analyzed, with attention to the number, signal intensity, and size of lesions. T2-weighted and diffusion-weighted images demonstrated 21 acute ischemic lesions in 14 patients. Six lesions had a long diameter of more than 3 cm, while the other 15 were smaller than 3 cm. On T2-weighted images, 17 lesions showed high signal intensity and four showed subtle high signal intensity. On diffusion-weighted images, all lesions showed bright high signal intensity. The six lesions larger than 3 cm were all delineated by all four kinds of perfusion MR imaging, but among the 15 smaller than 3 cm, only four (26.7%), five (33.3%) and six (40%) were delineated on rCBV and r CBF maps, the MTT map, and the TTP map, respectively. As compared with T2-weighted and diffusion-weighted imaging, the rCBV and rCBF maps showed that four lesions were smaller and six were the same size. On the MTT map, three lesions were seen to be larger, four were smaller, and the other four were the same size as they appeared on diffusion-weighted images, while on the TTP map, seven were larger and five were smaller than they appeared on these images. In all cases, diffusion-weighted images most clearly delineated acute ischemic lesions, regardless of lesion size. Many such lesions smaller than 3 cm were not apparent on perfusion

  8. Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

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    Gonzalez-Brito Manuel

    2008-02-01

    Full Text Available Abstract Background Assessment of cerebral blood flow (CBF by SPECT could be important in the management of patients with severe traumatic brain injury (TBI because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia, or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. Methods The focal effects of moderate traumatic brain injury (TBI on cerebral blood flow (CBF by SPECT cerebral blood perfusion (CBP imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM. Results A significant area of hypoperfusion (P Conclusion The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques.

  9. Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

    International Nuclear Information System (INIS)

    Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. The focal effects of moderate traumatic brain injury (TBI) on cerebral blood flow (CBF) by SPECT cerebral blood perfusion (CBP) imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM). A significant area of hypoperfusion (P < 0.01) was found as a response to the TBI. Statistical mapping of the reference microsphere CBF data confirms a focal decrease found with SPECT and SPM. The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques

  10. Interventional model establishment and computed tomography perfusion imaging for early diagnosis of acute cerebral infarction in dogs

    International Nuclear Information System (INIS)

    Objective: To establish interventionally a new canine model of focal cerebral infarction suitable to the study of imaging diagnosis and thrombolytic therapy, and to evaluate the application of computed tomography perfusion (CTP) in super acute ischemic cerebrovascular disease. Methods: Ten beagle adult dogs with self white thrombi of venous blood, injected into the left internal carotid arteries through 4F headhunter catheter selectively were created under fluoroscopic guidance. The cerebral angiography was performed before and after the embolization and the patency of the occluded cerebral arteries was observed with angiography at 1, 2 and 5 hours after the procedure. The CTP was performed at 2 hours after embolization. These dogs were sacrificed and their cerebra were taken out for pathologic study at 24th hour. Results: The occlusions of middle cerebral artery were shown angiographically in all 10 dogs with additional other cerebral arteries occlusion in 4. All occluded arteries were not recanalized at 2 hours after embolization, but the occluded arteries of 2 canines were partly recanalized at 5 hours. The regional cerebral blood flow (rCBF) was decreased to 48.3% ± 13.2% (33.7%-69.2%) in CTP of 9 canines showing no significant difference between digital subtraction angiography (DSA) and CTP (P>0.05). All dogs were survived at 24 hours without any severe complications. The cerebral infarction was found in deep part of cerebrum of all dogs. Conclusions: The establishment of acute cerebral infarction model in dogs with interventional technique is simple, micro invasive and reliable, for investigating CTP as a fast, accurate and no invasive method in evaluating the canine super acute ischemic cerebrovascular disease. (authors)

  11. TIPS bilateral noise reduction in 4D CT perfusion scans produces high-quality cerebral blood flow maps

    International Nuclear Information System (INIS)

    Cerebral computed tomography perfusion (CTP) scans are acquired to detect areas of abnormal perfusion in patients with cerebrovascular diseases. These 4D CTP scans consist of multiple sequential 3D CT scans over time. Therefore, to reduce radiation exposure to the patient, the amount of x-ray radiation that can be used per sequential scan is limited, which results in a high level of noise. To detect areas of abnormal perfusion, perfusion parameters are derived from the CTP data, such as the cerebral blood flow (CBF). Algorithms to determine perfusion parameters, especially singular value decomposition, are very sensitive to noise. Therefore, noise reduction is an important preprocessing step for CTP analysis. In this paper, we propose a time-intensity profile similarity (TIPS) bilateral filter to reduce noise in 4D CTP scans, while preserving the time-intensity profiles (fourth dimension) that are essential for determining the perfusion parameters. The proposed TIPS bilateral filter is compared to standard Gaussian filtering, and 4D and 3D (applied separately to each sequential scan) bilateral filtering on both phantom and patient data. Results on the phantom data show that the TIPS bilateral filter is best able to approach the ground truth (noise-free phantom), compared to the other filtering methods (lowest root mean square error). An observer study is performed using CBF maps derived from fifteen CTP scans of acute stroke patients filtered with standard Gaussian, 3D, 4D and TIPS bilateral filtering. These CBF maps were blindly presented to two observers that indicated which map they preferred for (1) gray/white matter differentiation, (2) detectability of infarcted area and (3) overall image quality. Based on these results, the TIPS bilateral filter ranked best and its CBF maps were scored to have the best overall image quality in 100% of the cases by both observers. Furthermore, quantitative CBF and cerebral blood volume values in both the phantom and the

  12. Detecting the subregion proceeding to infarction in hypoperfused cerebral tissue: a study with diffusion and perfusion weighted MRI.

    Science.gov (United States)

    Liu, Y; Karonen, J O; Vanninen, R L; Nuutinen, J; Perkiö, J; Vainio, P A; Soimakallio, S; Aronen, H J

    2003-06-01

    Diffusion and perfusion weighted MRI have been widely used in ischaemic stroke. We studied 17 patients in whom ischaemic areas showed an ischaemic core, an area of infarct growth and hypoperfused but ultimately surviving tissue. Apparent diffusion coefficients (ADC) were measured on days 1, 2, and 8 in the three subregions and in contralateral control areas. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were measured in these regions on day 1 perfusion maps. On day 1, the ischaemic core had very low ADC and CBF and increased MTT. The ADC in the ischaemic core gradually increased during the week. The area of infarct growth on day 1 had slightly but significantly decreased ADC (96% of control, P=0.028), moderately decreased CBF and increased MTT. On day 1 the hypoperfused but surviving tissue had slightly but significantly increased ADC (103% of control, P=0.001), mildly decreased CBF and increased CBV and MTT. The ADC of the area of infarct growth decreased to the same level as in the ischaemic core on days 2 and 8. That of surviving tissue was still above normal on day 2 (103% of control), but had returned to the normal level by day 8. Measurement of ADC combined with perfusion MRI may help distinguish different subregions in acutely hypoperfused brain. PMID:12750863

  13. Detecting the subregion proceeding to infarction in hypoperfused cerebral tissue: a study with diffusion and perfusion weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.; Vanninen, R.L.; Vainio, P.A.; Soimakallio, S. [Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, 70211, Kuopio (Finland); Karonen, J.O. [Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, 70211, Kuopio (Finland); Department of Radiology, Mikkeli Central Hospital, Mikkeli (Finland); Nuutinen, J. [Department of Neurology, Kuopio University Hospital, Kuopio (Finland); Perkioe, J. [Department of Radiology, Helsinki University Central Hospital (Finland); Department of Physical Sciences, University of Helsinki (Finland); Functional Brain Imaging Unit, Helsinki Brain Research Centre (Finland); Aronen, H.J. [Department of Clinical Radiology, Kuopio University Hospital, P.O. Box 1777, 70211, Kuopio (Finland); Department of Radiology, Helsinki University Central Hospital (Finland)

    2003-06-01

    Diffusion and perfusion weighted MRI have been widely used in ischaemic stroke. We studied 17 patients in whom ischaemic areas showed an ischaemic core, an area of infarct growth and hypoperfused but ultimately surviving tissue. Apparent diffusion coefficients (ADC) were measured on days 1, 2, and 8 in the three subregions and in contralateral control areas. Cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were measured in these regions on day 1 perfusion maps. On day 1, the ischaemic core had very low ADC and CBF and increased MTT. The ADC in the ischaemic core gradually increased during the week. The area of infarct growth on day 1 had slightly but significantly decreased ADC (96% of control, P=0.028), moderately decreased CBF and increased MTT. On day 1 the hypoperfused but surviving tissue had slightly but significantly increased ADC (103% of control, P=0.001), mildly decreased CBF and increased CBV and MTT. The ADC of the area of infarct growth decreased to the same level as in the ischaemic core on days 2 and 8. That of surviving tissue was still above normal on day 2 (103% of control), but had returned to the normal level by day 8. Measurement of ADC combined with perfusion MRI may help distinguish different subregions in acutely hypoperfused brain. (orig.)

  14. Effect of steroid on brain tumors and surround edemas : observation with regional cerebral blood volume (rCBV) maps of perfusion MRI

    International Nuclear Information System (INIS)

    To observe the hemodynamic change in brain tumors and peritumoral edemas after steroid treatment, and then investigate the clinical usefulness of perfusion MRI. We acquired conventional and perfusion MR images in 15 patients with various intracranial tumors (4 glioblastoma multiformes, 4 meningiomas, 3 metastatic tumors, 1 anaplastic ependymoma, 1 anaplastic astrocytoma, 1 hemangioblastoma, and 1 pilocytic astrocytoma). For perfusion MR imaging, a 1.5T unit employing the gradient-echo EPI technique was used, and further perfusion MR images were obtained 2-10 days after intravenous steroid therapy. After processing of the raw data, regional cerebral blood volume (rCBV) maps were reconstructed. The maps were visually evaluated by comparing relative perfusion in brain tumors and peritumoral edemas with that in contralateral white matter. Objective evaluations were performed by comparing the perfusion ratios of brain tumors and peritumoral edemas. Visual evaluations of rCBV maps, showed that in most brain tumors (67%, 10/15), perfusion was high before steroid treatment and showed in (80%, 12/15) decreased afterwards. Objective evaluation, showed that in all brain tumors, perfusion decreased. Visual evaluation of perfusion change in peritumoral edemas revealed change in only one case, but objective evaluation indicated that perfusion decreased significantly in all seven cases. rCBV maps acquired by perfusion MR imaging can provide hemodynamic information about brain tumors and peritumoral edemas. Such maps could prove helpful in the preoperative planning of brain tumor surgery and the monitoring of steroid effects during conservative treatment. (author)

  15. Effect of steroid on brain tumors and surround edemas : observation with regional cerebral blood volume (rCBV) maps of perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ju Youl; Sun, Joo Sung; Kim, Sun Yong; Kim, Ji Hyung; Suh, Jung Ho; Cho, Kyung Gi; Kim, Jang Sung [Ajou University, School of Medicine, Su won (Korea, Republic of)

    2000-01-01

    To observe the hemodynamic change in brain tumors and peritumoral edemas after steroid treatment, and then investigate the clinical usefulness of perfusion MRI. We acquired conventional and perfusion MR images in 15 patients with various intracranial tumors (4 glioblastoma multiformes, 4 meningiomas, 3 metastatic tumors, 1 anaplastic ependymoma, 1 anaplastic astrocytoma, 1 hemangioblastoma, and 1 pilocytic astrocytoma). For perfusion MR imaging, a 1.5T unit employing the gradient-echo EPI technique was used, and further perfusion MR images were obtained 2-10 days after intravenous steroid therapy. After processing of the raw data, regional cerebral blood volume (rCBV) maps were reconstructed. The maps were visually evaluated by comparing relative perfusion in brain tumors and peritumoral edemas with that in contralateral white matter. Objective evaluations were performed by comparing the perfusion ratios of brain tumors and peritumoral edemas. Visual evaluations of rCBV maps, showed that in most brain tumors (67%, 10/15), perfusion was high before steroid treatment and showed in (80%, 12/15) decreased afterwards. Objective evaluation, showed that in all brain tumors, perfusion decreased. Visual evaluation of perfusion change in peritumoral edemas revealed change in only one case, but objective evaluation indicated that perfusion decreased significantly in all seven cases. rCBV maps acquired by perfusion MR imaging can provide hemodynamic information about brain tumors and peritumoral edemas. Such maps could prove helpful in the preoperative planning of brain tumor surgery and the monitoring of steroid effects during conservative treatment. (author)

  16. [Changes in the cerebral hemodynamics during Rohypnol anesthesia in neurosurgical patients].

    Science.gov (United States)

    Gribkov, A V; Bakunin, L M; Rufova, N Iu

    1994-01-01

    Intracranial pressure, cerebral perfusion pressure, and intracerebral blood volume changes were observed in 43 patients with volumetric intracranial processes (intracranial hematomas, tumors) during general rohypnol anesthesia. Intracranial and cerebral perfusion pressures were found to correlate with intracerebral blood volume. Rohypnol anesthesia decreased intracranial pressure by 25% due to reduced arterial blood influx into the head, mechanisms responsible for autoregulation of cerebral circulation being intact. PMID:8209591

  17. Wound healing in above-knee amputations in relation to skin perfusion pressure

    DEFF Research Database (Denmark)

    Holstein, P; Dovey, H; Lassen, N A

    1979-01-01

    In 59 above-knee amputations healing of the stumps was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 1318-- or 125I--antipyrine mixed with histamine. Out of the 11 cases with an SPP below 30 mmHg no...

  18. Rapid identification of a major diffusion/perfusion mismatch in distal internal carotid artery or middle cerebral artery ischemic stroke

    Directory of Open Access Journals (Sweden)

    Hakimelahi Reza

    2012-11-01

    Full Text Available Abstract Background We tested the hypothesis that in patients with occlusion of the terminal internal carotid artery and/or the proximal middle cerebral artery, a diffusion abnormality of 70 ml or less is accompanied by a diffusion/perfusion mismatch of at least 100%. Methods Sixty-eight consecutive patients with terminal ICA and/or proximal MCA occlusions and who underwent diffusion/perfusion MRI within 24 hours of stroke onset were retrospectively identified. DWI and mean transit time (MTT volumes were measured. Prospectively, 48 consecutive patients were identified with the same inclusion criteria. DWI and time to peak (TTP lesion volumes were measured. A large mismatch volume was defined as an MTT or TTP abnormality at least twice the DWI lesion volume. Results In the retrospective study, 49 of 68 patients had a DWI lesion volume ≤ 70 ml (mean 20.2 ml; SEM 2.9 ml. A DWI/MTT mismatch of > 100% was observed in all 49 patients (P  100% was present in all 35 (P  Conclusions Acute stroke patients with major anterior circulation artery occlusion are exceedingly likely to have a major diffusion/perfusion mismatch if the diffusion lesion volume is 70 ml or less. This suggests that physiology-based patient assessments may be made using only vessel imaging and diffusion MRI as a simple alternative to perfusion imaging.

  19. A higher prevalence of abnormal regional cerebral blood flow in patients with syndrome X and abnormal myocardial perfusion

    International Nuclear Information System (INIS)

    To test the hypothesis that syndrome X is a systemic vascular disorder, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in 30 patients with syndrome X. These patients were separated into group 1, 20 patients with definite myocardial perfusion defects diagnosed by thallium-201 (Tl-201) myocardial perfusion SPECT; and group 2, 10 patients without any myocardial perfusion defects. Tc-99m ECD brain SPECT demonstrated hypoperfusion brain lesions in 95% (19/20) and 20% (2/10) of patients in groups 1 and 2, respectively. This difference in the cidence between the two groups was significant. In group 1 and 2 patients, parietal lobes were the most common hypoperfusion areas, while the cerebellum was the least common hypoperfusion area of the brain. Syndrome X is a systemic vascular disorder with a high incidence of hypoperfusion lesions of the brain based on the findings of Tc-99m ECD brain SPECT, and is usually coincident with myocardial defects based on the Tl-201 myocardial perfusion SPECT findings. (author)

  20. Cerebral perfusion MR imaging using FAIR-HASTE in chronic carotid occlusive disease: comparison with dynamic susceptibility contrast-perfusion MR imaging.

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    Ida,Kentaro

    2006-08-01

    Full Text Available To determine the efficacy of flow-sensitive alternating inversion recovery using half-Fourier single-shot turbo spin-echo (FAIR-HASTE in detecting cerebral hypoperfusion in chronic carotid occlusive disease, we subjected 12 patients with various degrees of cervical internal carotid artery stenoses and/or occlusion (Stenosis group and 24 volunteers (Normal group to FAIR-HASTE. In addition, 10 out of 12 patients in the Stenosis group underwent dynamic susceptibility contrast-perfusion magnetic resonance imaging (DSC-pMRI before and after revascularization in the dominantly affected side. The absolute asymmetry indexes (AIs of both cerebral hemispheres in the Normal and Stenosis groups were compared in FAIR-HASTE. In addition, the AIs were compared with those in the Stenosis group before and after revascularization in both FAIR-HASTE and regional cerebral blood flow (rCBF, calculated with DSC-pMRI. A statistically significant difference was recognized between the AIs in the Normal and Stenosis groups (AI = 2.25 +- 1.92, 8.09 +- 4.60, respectively ; p < 0.0001. Furthermore, in the Stenosis group the AIs on both FAIR-HASTE (8.88 +- 4.93, 2.22 +- 1.79, respectively ; p = 0.0003 and rCBF (7.13 +- 3.57, 1.25 +- 1.33, respectively ; p = 0.0003 significantly decreased after revascularization. In the Stenosis group, before revascularization, signal intensity on both FAIR-HASTE and rCBF had a tendency to be lower in the dominantly affected side. FAIR-HASTE imaging was useful in the detection and evaluation of cerebral hypoperfusion in chronic occlusive carotid disease.

  1. Noninvasive measurements of regional cerebral perfusion in preterm and term neonates by magnetic resonance arterial spin labeling

    DEFF Research Database (Denmark)

    Miranda Gimenez-Ricco, Maria Jo; Olofsson, K; Sidaros, Karam

    2006-01-01

    Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term...... higher (p < 0.0001) than in cortical gray matter (19 and 16 mL/100 g/min) and white matter (15 and 10 mL/100 g/min), both in preterm neonates at term-equivalent age and in term neonates. Perfusion was significantly higher (p = 0.01) in the preterm group than in the term infants, indicating that RCP may...... be influenced by developmental and postnatal ages. This study demonstrates, for the first time, that noninvasive ASL at 3T may be used to measure RCP in healthy unsedated preterm and term neonates. ASL is, therefore, a viable tool that will allow serial studies of RCP in high-risk neonates...

  2. Initial intramuscular perfusion pressure predicts early skeletal muscle function following isolated tibial fractures

    Directory of Open Access Journals (Sweden)

    Haas Norbert P

    2008-04-01

    Full Text Available Abstract Background The severity of associated soft tissue trauma in complex injuries of the extremities guides fracture treatment and decisively determines patient's prognosis. Trauma-induced microvascular dysfunction and increased tissue pressure is known to trigger secondary soft tissue damage and seems to adversely affect skeletal muscle function. Methods 20 patients with isolated tibial fractures were included. Blood pressure and compartment pressure (anterior and deep posterior compartment were measured continuously up to 24 hours. Corresponding perfusion pressure was calculated. After 4 and 12 weeks isokinetic muscle peak torque and mean power of the ankle joint in dorsal and plantar flexion were measured using a Biodex dynamometer. Results A significant inverse correlation between the anterior perfusion pressure at 24 hours and deficit in dorsiflexion at 4 weeks was found for both, the peak torque (R = -0.83; p Conclusion The functional relationship between the decrease in intramuscular perfusion pressures and muscle performance in the early rehabilitation period indicate a causative and prognostic role of early posttraumatic microcirculatory derangements and skeletal muscle function. Therapeutic concepts aimed at effective muscle recovery, early rehabilitation, and decreased secondary tissue damage, should consider the maintenance of an adequate intramuscular perfusion pressure.

  3. Perfusion of lung periphery: effects of local exposures to ozone and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Freed, A.N.; Scheffel, U.A.; Kelly, L.J.; Bromberger-Barnea, B.; Menkes, H.A.

    1986-08-01

    Following ozone (O/sub 3/) exposure, airways reactivity increases. We investigated the possibility that exposure to O/sub 3/ causes a decrease in pulmonary perfusion, and that this decrease is associated with the increase in reactivity. Perfusion was measured with radiolabeled microspheres. A wedged bronchoscope was used to isolate sublobar segments in the middle and lower lobes of anesthetized dogs. Isolated segments were exposed to either O/sub 3/ or an elevated alveolar pressure. Although increased alveolar pressure decreased microsphere density, exposure to 1 ppm O/sub 3/ did not. Collateral system resistance rose significantly following exposure to O/sub 3/ and to high pressure. These studies do not support the hypothesis that pulmonary perfusion is decreased following O/sub 3/ exposure and is associated with subsequent increases in reactivity.

  4. Altered cerebral blood flow one month after systemic chemotherapy for breast cancer: a prospective study using pulsed arterial spin labeling MRI perfusion.

    Directory of Open Access Journals (Sweden)

    Kelly N H Nudelman

    Full Text Available Cerebral structural and functional alterations have been reported after chemotherapy for non-CNS cancers, yet the causative mechanism behind these changes remains unclear. This study employed a novel, non-invasive, MRI-based neuroimaging measure to provide the first direct longitudinal measurement of resting cerebral perfusion in breast cancer patients, which was tested for association with changes in cognitive function and gray matter density. Perfusion was measured using pulsed arterial spin labeling MRI in women with breast cancer treated with (N = 27 or without (N = 26 chemotherapy and matched healthy controls (N = 26 after surgery before other treatments (baseline, and one month after chemotherapy completion or yoked intervals. Voxel-based analysis was employed to assess perfusion in gray matter; changes were examined in relation to overall neuropsychological test performance and frontal gray matter density changes measured by structural MRI. Baseline perfusion was not significantly different across groups. Unlike control groups, chemotherapy-treated patients demonstrated significantly increased perfusion post-treatment relative to baseline, which was statistically significant relative to controls in the right precentral gyrus. This perfusion increase was negatively correlated with baseline overall neuropsychological performance, but was not associated with frontal gray matter density reduction. However, decreased frontal gray matter density was associated with decreased perfusion in bilateral frontal and parietal lobes in the chemotherapy-treated group. These findings indicate that chemotherapy is associated with alterations in cerebral perfusion which are both related to and independent of gray matter changes. This pattern of results suggests the involvement of multiple mechanisms of chemotherapy-induced cognitive dysfunction. Additionally, lower baseline cognitive function may be a risk factor for treatment

  5. Glycopyrrolate does not influence the visual or motor-induced increase in regional cerebral perfusion

    DEFF Research Database (Denmark)

    Rokamp, Kim Z; Olesen, Niels D; Larsson, Henrik B W; Hansen, Adam E; Seifert, Thomas; Nielsen, Henning B; Secher, Niels H; Rostrup, Egill

    2014-01-01

    vasodilatation is important for the increase in rCBF during cerebral activation. The subjects were 11 young healthy males at an age of 24 ± 3 years (mean ± SD). We used arterial spin labeling and blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to evaluate rCBF with and without...... intravenous glycopyrrolate during a handgrip motor task and visual stimulation. Glycopyrrolate increased heart rate from 56 ± 9 to 114 ± 14 beats/min (mean ± SD; p < 0.001), mean arterial pressure from 86 ± 8 to 92 ± 12 mmHg, and cardiac output from 5.6 ± 1.4 to 8.0 ± 1.7 l/min. Glycopyrrolate had, however...

  6. Differential Features of Cerebral Perfusion in Dementia with Lewy Bodies Compared to Alzheimer's Dementia using SPM Analysis

    International Nuclear Information System (INIS)

    Alzheimer's dementia (AD) and dementia with Lewy bodies (DLB) are most common cause of dementia in elderly people. Clinical distinction in some cases of DLB from AD may be difficult as symptom profiles overlap. Some neuropathologic overlap is also seen as beta-amyloidosis and senile plaques can be found in both disease. Both disease also share severe acetylcholine depletion. We evaluated the differences of brain perfusion between DLB and AD using statistical parametric mapping analysis. Twelve DLB (mean age ; 68.8±8.3 years, K-MMSE ; 17.3±6.1) and 51 AD patients (mean age ; 71.4±7.2 years, K-MMSE ; 16.7±4.5), which were matched for age and severity of dementia, participated in this study. Tc-99m HMPAO SPECT was performed for measuring regional cerebral blood flow. Statistical parametric mapping (SPM99) software was used for automatic and objective approach to analyze SPECT image data. The SPECT data of the patients with DLB were compared to patients with AD. Comparison of the two dementia groups (uncorrected p<0.01) revealed significant hypoperfusion in both occipital (both middle occipital gyrus, Rt B no. 18 and Lt cuneus), both parietal (Lt parietal precuneus, Lt B no. 39, Lt inferior parietal lobule and Rt supramarginal gyrus) lobes in DLB compared with AD. Significant hyperperfusion was noted in Rt frontal (sup. frontal gyrus, B no.10, middle frontal gyrus, B no. 9, B no. 11, inf. frontal gyrus), Rt putamen, Lt ant. cingulate gyrus (B no. 24), both cerebellar post. lobe (Lt tuber, Lt declive, Lt tonsil, Rt declive) in DLB compared with AD. We found a significant differences in the cerebral perfusion pattern between DLB and AD. Differential feature of cerebral perfusion in DLB was both occipital hypoperfusion and preserved Rt frontal perfusion compared to AD. Therefore in difficult case of clinical an neuro pathologic diagnosis, brain perfusion SPECT with SPM analysis may be helpful to differentiate DLB from AD

  7. In-vitro investigation of cerebral-perfusion effects of a rotary blood pump installed in the descending aorta.

    Science.gov (United States)

    Rezaienia, Mohammad Amin; Paul, Gordon; Avital, Eldad; Rahideh, Akbar; Rothman, Martin Terry; Korakianitis, Theodosios

    2016-06-14

    This study describes use of a cardiovascular simulator to replicate the hemodynamic responses of the cerebrovascular system with a mechanical circulatory support device operating in the descending aorta. To do so, a cerebral autoregulation unit was developed which replicates the dilation and constriction of the native cerebrovascular resistance system and thereby regulates the cerebral flow rate within defined limits. The efficacy of the replicated autoregulation mechanism was investigated by introducing a number of step alterations in mean aortic pressure and monitoring the cerebral flow. The steady responses of the cerebral flow to changes in mean aortic pressure were in good agreement with clinical data. Next, a rotary pump, modeling a mechanical circulatory support device, was installed in the descending aorta and the hemodynamic responses of the cerebral system were investigated over a wide range of pump operating conditions. Insertion of a mechanical circulatory support device in the descending aorta presented an improved cardiac output as a result of afterload reduction. It was observed that the primary drop in cerebral flow, caused by the pump in the descending aorta, was compensated over the course of five seconds due to a gradual decrease in cerebrovascular resistance. The experimental results suggest that the implantation of a mechanical circulatory support device in the descending aorta, a less invasive procedure than typical mechanical circulatory support implantation, will not have an adverse effect on the cognitive function, provided that the cerebral autoregulation is largely unimpaired. PMID:27155746

  8. Potential of optical microangiography to monitor cerebral blood perfusion and vascular plasticity following traumatic brain injury in mice in vivo

    Science.gov (United States)

    Jia, Yali; Alkayed, Nabil; Wang, Ruikang K.

    2009-07-01

    Optical microanglography (OMAG) is a recently developed imaging modality capable of volumetric imaging of dynamic blood perfusion, down to capillary level resolution, with an imaging depth up to 2.00 mm beneath the tissue surface. We report the use of OMAG to monitor the cerebral blood flow (CBF) over the cortex of mouse brain upon traumatic brain injury (TBI), with the cranium left intact, for a period of two weeks on the same animal. We show the ability of OMAG to repeatedly image 3-D cerebral vasculatures during pre- and post-traumatic phases, and to visualize the changes of regulated CBF and the vascular plasticity after TBI. The results indicate the potential of OMAG to explore the mechanism involved in the rehabilitation of TBI.

  9. Biliary pressure: manometric and perfusion studies at percutaneous transhepatic cholangiography and percutaneous biliary drainage

    International Nuclear Information System (INIS)

    Manometric pressure recordings were attempted during percutaneous transhepatic cholangiography (PTC) and after percutaneous biliary drainage (PBD) in 203 cases. Successful readings were achieved at PTC in 85% (104/122) of patients. Pressure measurements were also obtained through 56 biliary drainage catheters, and controlled perfusion challenges were performed in 12 patients (on 18 occasions). Documentation of the occasionally poor correlation between the caliber of ducts and the degree of obstruction (i.e., pressure) was shown, and it was suggested that very high pressures may be predictive of a bile leak after PTC. Adequacy of percutaneous drainage and stricture dilatation were further assessed with these manometric techniques. Pressure and perfusion data aided in detecting and determining the significance of the nondilated obstructed duct, the dilated nonobstructed ductal system, and subtle distal ductal strictures. The knowledge obtained from percutaneous pressure recordings may help to determine appropriate therapy

  10. Effects of ovariohysterectomy on intra-abdominal pressure and abdominal perfusion pressure in cats.

    Science.gov (United States)

    Bosch, L; Rivera del Álamo, M M; Andaluz, A; Monreal, L; Torrente, C; García-Arnas, F; Fresno, L

    2012-12-15

    Intra-abdominal pressure (IAP) and abdominal perfusion pressure (APP) have shown clinical relevance in monitoring critically ill human beings submitted to abdominal surgery. Only a few studies have been performed in veterinary medicine. The aim of this study was to assess how pregnancy and abdominal surgery may affect IAP and APP in healthy cats. For this purpose, pregnant (n=10) and non-pregnant (n=11) queens undergoing elective spaying, and tomcats (n=20, used as controls) presented for neutering by scrotal orchidectomy were included in the study. IAP, mean arterial blood pressure (MAP), APP, heart rate and rectal temperature (RT) were determined before, immediately after, and four hours after surgery. IAP increased significantly immediately after abdominal surgery in both female groups when compared with baseline (P<0.05) and male (P<0.05) values, and returned to initial perioperative readings four hours after surgery. Tomcats and pregnant females (P<0.05) showed an increase in MAP and APP immediately after surgery decreasing back to initial perioperative values four hours later. A significant decrease in RT was appreciated immediately after laparotomy in both pregnant and non-pregnant queens. IAP was affected by abdominal surgery in this study, due likely to factors, such as postoperative pain and hypothermia. Pregnancy did not seem to affect IAP in this population of cats, possibly due to subjects being in early stages of pregnancy. PMID:23118052

  11. Color-coded perfused blood volume imaging using multidetector CT: initial results of whole-brain perfusion analysis in acute cerebral ischemia

    International Nuclear Information System (INIS)

    Computed tomography (CT) is still the primary imaging modality following acute stroke. To evaluate a prototype of software for the calculation of color-coded whole-brain perfused blood volume (PBV) images from CT angiography (CTA) and nonenhanced CT (NECT) scans, we studied 14 patients with suspected acute ischemia of the anterior cerebral circulation. PBV calculations were performed retrospectively. The detection rate of ischemic changes in the PBV images was compared with NECT. The volume of ischemic changes in PBV was correlated with the infarct volume on follow-up examination taking potential vessel recanalization into account. PBV demonstrated ischemic changes in 12/12 patients with proven infarction and was superior to NECT (8/12) in the detection of early ischemia. Moreover, PBV demonstrated the best correlation coefficient with the follow-up infarct volume (Pearson's R = 0.957; P = 0.003) for patients with proven recanalization of initially occluded cerebral arteries. In summary, PBV appears to be more accurate in the detection of early infarction compared to NECT and mainly visualizes the irreversibly damaged ischemic tissue. (orig.)

  12. Visual and SPM analysis of regional cerebral perfusion with Tc-99m ECD brain SPECT in patients with developmental language disorder

    International Nuclear Information System (INIS)

    Developmental language disorder (DLD) refers to inadequate language acquisition at the expected age in children with otherwise normal development. However, language delay can be observed in patients with other developmental disoder (ODD). We, therefore, evaluated regional cerebral perfusion pattern in patients with DLD and ODD by means of visual and SPM analysis. Twelve patients, who underwent Tc-99m ECD brain SPECT within 3 weeks of their first visit, were included in the study. Psychological and language tests classified the patients into 2 groups ; 6 with DLD (3-7 yr, 5 male and I female) and 6 with ODD (2-6 yr, 6 male). Visual analysis for regional cerebral perfusion was done in each patient. SPM with 7 controls (age=7) was performed to evaluate difference between 2 groups using t-test. P value of less than 0.005 was considered to be significant. All patients had significant language delay for their age (9 month 3.5 yr). Among 6 patients with ODD, 4 had pervasive developmental disorder, 1 mental retardation and 1 attachment disorder. Visual analysis revealed significant perfusion decrease in only 1 patient with DLD and 2 with ODD ; the regions were left parieto-temporal cortex, both frontal and cerebellar cortices, and right temporal cortex respectively. Nine of 12 patients showed normal perfusion. SPM demonstrated perfusion decrease in left inferior frontal cortex and left superior parietal cortex (Wernicke's area) in patients with DLD, while, in patients with ODD, perfusion decrease was mostly located in the right hemisphere (lateral frontoorbital gyrus, occipitotemporal gyrus, cuneus and cerebellum). Corpus callosum showed no significant perfusion abnormality in both groups. Regional cerebral perfusion of patients with DLD, which was mainly located in the speech area, is quite different from that of ODD-patients with language delay. While SPM successfully revealed this difference in perfusion pattern, visual analysis had limited value

  13. Visual and SPM analysis of regional cerebral perfusion with Tc-99m ECD brain SPECT in patients with developmental language disorder

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon Kee; Lee, Myung Hoon; Joh, Chul Woo; Yoon, Seok Nam; Oh, Eun Young [College of Medicine, Univ. of Ajou, Suwon (Korea, Republic of)

    2003-07-01

    Developmental language disorder (DLD) refers to inadequate language acquisition at the expected age in children with otherwise normal development. However, language delay can be observed in patients with other developmental disoder (ODD). We, therefore, evaluated regional cerebral perfusion pattern in patients with DLD and ODD by means of visual and SPM analysis. Twelve patients, who underwent Tc-99m ECD brain SPECT within 3 weeks of their first visit, were included in the study. Psychological and language tests classified the patients into 2 groups ; 6 with DLD (3-7 yr, 5 male and I female) and 6 with ODD (2-6 yr, 6 male). Visual analysis for regional cerebral perfusion was done in each patient. SPM with 7 controls (age=7) was performed to evaluate difference between 2 groups using t-test. P value of less than 0.005 was considered to be significant. All patients had significant language delay for their age (9 month 3.5 yr). Among 6 patients with ODD, 4 had pervasive developmental disorder, 1 mental retardation and 1 attachment disorder. Visual analysis revealed significant perfusion decrease in only 1 patient with DLD and 2 with ODD ; the regions were left parieto-temporal cortex, both frontal and cerebellar cortices, and right temporal cortex respectively. Nine of 12 patients showed normal perfusion. SPM demonstrated perfusion decrease in left inferior frontal cortex and left superior parietal cortex (Wernicke's area) in patients with DLD, while, in patients with ODD, perfusion decrease was mostly located in the right hemisphere (lateral frontoorbital gyrus, occipitotemporal gyrus, cuneus and cerebellum). Corpus callosum showed no significant perfusion abnormality in both groups. Regional cerebral perfusion of patients with DLD, which was mainly located in the speech area, is quite different from that of ODD-patients with language delay. While SPM successfully revealed this difference in perfusion pattern, visual analysis had limited value.

  14. Characteristic patterns of cerebral blood perfusion and cognitive impairment in patients with Parkinsons disease

    International Nuclear Information System (INIS)

    Parkinsons disease (PD) is a neurodegenerative disorder that represents cognitive impairment as well as motor symptoms. Even in the early stages of PD, cognitive alterations can be demonstrated by careful neuropsychological test. The purposes of this study are to investigate the pattern of cognitive impairment and the regional cerebral blood flow (rCBF) using Tc-99m HMPAO SPECT in patients with PD. One hundred and twenty two patients with PD and 35 control subjects participated in this study. Patients with PD who had dementia clinically or K-MMSE score below 25 points or with severe motor dysfunction to interfere with the tests were also excluded. They were all matched for age (61±10 vs 61±8), education periods (8.8±4.9 vs 8.8±4.5), and K-MMSE score (27±1.6 vs 27±1.5). All subjects were evaluated using the Seoul Neuropsychological Screening Battery (SNSB) and Tc-99m HMPAO SPECT with SPM software to measure rCBF. Patients with PD performed worse in digit span backward, Rey Complex Figure Test, visual memory, semantic fluency, stroop test, and alternating hand movement test(p<0.05) compared with control group. On SNSB test, 100 patients (82.0%) showed some abnormalities. Eighty-six patients (70.5%) showed frontal dysfunction, 47 (38.5%) memory impairment, 33 (27.0%) language dysfunction, 25 (20.5%) attention deficit and 22 (18.3%) visuospatial dysfunction in the order of frequency. Eight patients with PD showed single memory domain MCI and 28 single non-memory domain MCI (20 frontal dysfunction). Multiple domain MCI was found in 64 patients with PD. SPM analysis of the SPECT image revealed multiple perfusion deficit in the both frontal, temporal, both limbic lobes, Lt. parietal and Lt. Putamen. It is concluded that abnormalities of cognitive function be detected very commonly in patients with PD. MCI in PD patients is most frequently involved in the item of frontal lobe function. SPECT image might be helpful to explain cognitive impairment in some PD patients

  15. Cerebral Metabolic Profiling of Hypothermic Circulatory Arrest with and Without Antegrade Selective Cerebral Perfusion: Evidence from Nontargeted Tissue Metabolomics in a Rabbit Model

    Science.gov (United States)

    Zou, Li-Hua; Liu, Jin-Ping; Zhang, Hao; Wu, Shu-Bin; Ji, Bing-Yang

    2016-01-01

    Background: Antegrade selective cerebral perfusion (ASCP) is regarded to perform cerebral protection during the thoracic aorta surgery as an adjunctive technique to deep hypothermic circulatory arrest (DHCA). However, brain metabolism profile after ASCP has not been systematically investigated by metabolomics technology. Methods: To clarify the metabolomics profiling of ASCP, 12 New Zealand white rabbits were randomly assigned into 60 min DHCA with (DHCA+ASCP [DA] group, n = 6) and without (DHCA [D] group, n = 6) ASCP according to the random number table. ASCP was conducted by cannulation on the right subclavian artery and cross-clamping of the innominate artery. Rabbits were sacrificed 60 min after weaning off cardiopulmonary bypass. The metabolic features of the cerebral cortex were analyzed by a nontargeted metabolic profiling strategy based on gas chromatography-mass spectrometry. Variable importance projection values exceeding 1.0 were selected as potentially changed metabolites, and then Student's t-test was applied to test for statistical significance between the two groups. Results: Metabolic profiling of brain was distinctive significantly between the two groups (Q2Y = 0.88 for partial least squares-DA model). In comparing to group D, 62 definable metabolites were varied significantly after ASCP, which were mainly related to amino acid metabolism, carbohydrate metabolism, and lipid metabolism. Kyoto Encyclopedia of Genes and Genomes analysis revealed that metabolic pathways after DHCA with ASCP were mainly involved in the activated glycolytic pathway, subdued anaerobic metabolism, and oxidative stress. In addition, L-kynurenine (P = 0.0019), 5-methoxyindole-3-acetic acid (P = 0.0499), and 5-hydroxyindole-3-acetic acid (P = 0.0495) in tryptophan metabolism pathways were decreased, and citrulline (P = 0.0158) in urea cycle was increased in group DA comparing to group D. Conclusions: The present study applied metabolomics analysis to identify the cerebral

  16. Three-dimensional mapping of local cerebral perfusion in alcoholic encephalopathy with and without Wernicke-Korsakoff syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hata, T.; Meyer, J.S.; Tanahashi, N.; Ishikawa, Y.; Imai, A.; Shinohara, T.; Velez, M.; Fann, W.E.; Kandula, P.; Sakai, F.

    1987-02-01

    Seventeen severe chronic alcoholic patients with and without Wernicke-Korsakoff syndrome (WKS) were examined prospectively after being treated by withdrawal from alcohol. The WKS patients also received thiamine supplements. Three-dimensional measurements of local cerebral blood flow (LCBF) and local partition coefficients (L lambda) were made utilizing xenon contrast computed tomography (Xe CT-CBF). Results were displayed as color-coded brain maps before and after treatment and these were correlated with neurological and cognitive examinations. Before treatment chronic alcoholics without WKS (n = 10) showed diffuse reductions of LCBF values throughout all gray matter including hypothalamus, vicinity of nucleus basalis of Meynert, thalamus, and basal ganglia. Similar, but more severe, reductions were seen in patients with WKS (n = 7), however, white matter perfusion was also reduced. In WKS, most prominent reductions of LCBF were also seen in hypothalamus and basal forebrain nuclei but thalamus, basal ganglia, and limbic systems were severely reduced. After treatment, both groups with alcoholic encephalopathy showed marked clinical improvement and cerebral perfusion was restored toward normal. Chronic alcohol abuse, in the absence of thiamine deficiency, reduces CBF by direct neurotoxic effects. If thiamine deficiency is also present, more severe and localized hemodynamic reductions are superimposed.

  17. Three-dimensional mapping of local cerebral perfusion in alcoholic encephalopathy with and without Wernicke-Korsakoff syndrome

    International Nuclear Information System (INIS)

    Seventeen severe chronic alcoholic patients with and without Wernicke-Korsakoff syndrome (WKS) were examined prospectively after being treated by withdrawal from alcohol. The WKS patients also received thiamine supplements. Three-dimensional measurements of local cerebral blood flow (LCBF) and local partition coefficients (L lambda) were made utilizing xenon contrast computed tomography (Xe CT-CBF). Results were displayed as color-coded brain maps before and after treatment and these were correlated with neurological and cognitive examinations. Before treatment chronic alcoholics without WKS (n = 10) showed diffuse reductions of LCBF values throughout all gray matter including hypothalamus, vicinity of nucleus basalis of Meynert, thalamus, and basal ganglia. Similar, but more severe, reductions were seen in patients with WKS (n = 7), however, white matter perfusion was also reduced. In WKS, most prominent reductions of LCBF were also seen in hypothalamus and basal forebrain nuclei but thalamus, basal ganglia, and limbic systems were severely reduced. After treatment, both groups with alcoholic encephalopathy showed marked clinical improvement and cerebral perfusion was restored toward normal. Chronic alcohol abuse, in the absence of thiamine deficiency, reduces CBF by direct neurotoxic effects. If thiamine deficiency is also present, more severe and localized hemodynamic reductions are superimposed

  18. CT perfusion assessment of Moyamoya syndrome before and after direct revascularization (superficial temporal artery to middle cerebral artery bypass)

    International Nuclear Information System (INIS)

    To evaluate the utility of CT perfusion (CTP) for the assessment of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with Moyamoya syndrome (MMS). Twenty-four consecutive MMS patients, who underwent unilateral STA-MCA bypass surgery, received CTP before and after surgery. The relative perfusion parameter values of surgical hemispheres before treatment were compared with post-treatment values. All patients underwent CT angiography (CTA) before and after surgery in order to confirm the patency of bypass. The follow-up CTA after surgery clearly demonstrated 20 (20/24, 83.3 %) bypass arteries, whereas four (16.7 %) bypass arteries were occluded or very small. Postoperative rMTT and rTTP values (P < 0.05) of the surgical side were significantly lower than pre-operation. In patients (n = 20) with bypass patency, postoperative rCBF, rMTT and rTTP values (P < 0.05) of the surgical side were significantly improved. However, the differences of all parameters were not significant (P > 0.05) in the patients (n = 4) without bypass patency after revascularization. This study demonstrates that CTP can provide a crucial quantitative assessment of cerebral haemodynamic changes in MMS before and after STA-MCA anastomosis. (orig.)

  19. Initial study of 3D perfused blood volume imaging using 64-detector CT in hyperacute cerebral infarction

    International Nuclear Information System (INIS)

    Objective: To evaluate the value of three dimensional CT whole brain perfused blood volume (3D-PBV) based on CTA row data in hyperacute cerebral infarction. Methods: 38 patients with stroke within 12 hours performed plain CT and CTA scans. 3D software Neuro PBV was applied to process the CTA row data and 3D-PBV of brain was obtained. MR examinations were performed within 2 hours after CT scans. The numbers of ischemic lesions on plain CT, 3D-PBV and MRI-DWI were recorded. The volumes of ischemic lesions on 3D-PBV and MR -DWI were measured. Results: In 38 patients, the number of infarct lesion detected by MRI-DWI, PBV, and plain CT was 45, 41, and 16 respectively. Kappa test showed a substantial agreement (κ=0.78) between 3D-PBV and MRI-DWI in detecting ischemic lesions. The detectability of plain CT showed fair or slight agreements to 3D-PBV and MR-DWI (κ=0.24, 0.18, respectively). The lesion volumes did not differ on 3D-PBV and MR-DWI (t=7.249, P>0.05). Conclusion: 3D-PBV combined with CTA can detect ischemic lesion and evaluate perfusion. It had important value in diagnosing hyperacute cerebral infarction. (authors)

  20. CT perfusion assessment of Moyamoya syndrome before and after direct revascularization (superficial temporal artery to middle cerebral artery bypass)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yueqin [Hospital of Qingdao University, Department of Radiology, Qingdao (China); Hospital of Jining Medical College, CT Department, Jining (China); Xu, Wenjian [Hospital of Qingdao University, Department of Radiology, Qingdao (China); Guo, Xiang; Shi, Zhitao; Sun, Zhanguo; Wang, Jiehuan [Hospital of Jining Medical College, CT Department, Jining (China); Gao, Lingyun [Hospital of Jining Medical College, MR Department, Jining (China); Jin, Feng [Hospital of Jining Medical College, Department of Neurosurgery, Jining (China); Chen, Weijian; Yang, Yunjun [Hospital of Wenzhou Medical University, Department of Radiology, Wenzhou (China)

    2016-01-15

    To evaluate the utility of CT perfusion (CTP) for the assessment of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in patients with Moyamoya syndrome (MMS). Twenty-four consecutive MMS patients, who underwent unilateral STA-MCA bypass surgery, received CTP before and after surgery. The relative perfusion parameter values of surgical hemispheres before treatment were compared with post-treatment values. All patients underwent CT angiography (CTA) before and after surgery in order to confirm the patency of bypass. The follow-up CTA after surgery clearly demonstrated 20 (20/24, 83.3 %) bypass arteries, whereas four (16.7 %) bypass arteries were occluded or very small. Postoperative rMTT and rTTP values (P < 0.05) of the surgical side were significantly lower than pre-operation. In patients (n = 20) with bypass patency, postoperative rCBF, rMTT and rTTP values (P < 0.05) of the surgical side were significantly improved. However, the differences of all parameters were not significant (P > 0.05) in the patients (n = 4) without bypass patency after revascularization. This study demonstrates that CTP can provide a crucial quantitative assessment of cerebral haemodynamic changes in MMS before and after STA-MCA anastomosis. (orig.)

  1. Comparative evaluation of cerebral blood volume and cerebral blood flow in acute ischemic stroke by using perfusion-weighted MR imaging and SPECT

    International Nuclear Information System (INIS)

    Purpose: To investigate the relationship between relative cerebral blood volume (CBV) measured with perfusion-weighted (PW) MR imaging and relative cerebral blood flow (CBF) measured with SPECT in acute ischemic stroke. Material and Methods: Fifteen patients who had acute unilateral middle cerebral artery occlusion underwent both PW MR imaging and 99mTc-HMPAO SPECT with an interval less than 20 minutes between the two examinations within 6 hours after stroke onset. Lesion-to-contralateral relative CBV and CBF ratios measured in multiple regions of interest were compared to evaluate the relationship of the two parameters. Results: An overall linear relationship was found between relative CBV and relative CBF ratios (R2=0.54, p0.05). Regions with evolving infarction had more severe hypoperfusion (mean relative CBF ratio, 0.38±0.22) than regions without (mean relative CBF ratio, 0.70±0.13) (p<0.0001). Conclusion: A significant linear relationship existed between relative CBV and relative CBF in acute ischemic stroke, although relative CBV did not change linearly to relative CBF in mild hypoperfusion. Relative CBV can be used as an alternative to relative CBF within 6 hours after stroke onset, particularly in regions with severe hypoperfusion proceeding to infarction

  2. Intracranial pressure pulse morphological features improved detection of decreased cerebral blood flow

    International Nuclear Information System (INIS)

    We investigated whether intracranial pressure (ICP) pulse morphological metrics could be used to realize continuous detection of low cerebral blood flow. Sixty-three acutely brain injured patients with ICP monitoring, daily 133Xenon cerebral blood flow (CBF) and daily transcranial Doppler (TCD) assessments were studied. Their ICP recordings were time-aligned with the CBF and TCD measurements so that a 1 h ICP segment near the CBF and TCD measurements was obtained. Each of these recordings was processed by the Morphological Cluster and Analysis of Intracranial Pressure (MOCAIP) algorithm to extract pulse morphological metrics. Then the differential evolution algorithm was used to find the optimal combination of the metrics that provided, using the regularized linear discriminant analysis, the largest combined positive predictivity and sensitivity. At a CBF threshold of 20 ml/min/100 g, a sensitivity of 81.8 ± 0.9% and a specificity of 50.1 ± 0.2% were obtained using the optimal combination of conventional TCD and blood analysis metrics as input to a regularized linear classifier. However, using the optimal combination of the MOCAIP metrics alone we were able to achieve a sensitivity of 92.5 ± 0.7% and a specificity of 84.8 ± 0.8%. Searching the optimal combination of all available metrics, we achieved the best result that was marginally better than those from using MOCAIP alone. This study demonstrated that the potential role of ICP monitoring may be extended to provide an indicator of low global cerebral blood perfusion

  3. Using Flat-Panel Perfusion Imaging to Measure Cerebral Hemodynamics: A Pilot Feasibility Study in Patients With Carotid Stenosis.

    Science.gov (United States)

    Lin, Chung-Jung; Guo, Wan-Yuo; Chang, Feng-Chi; Hung, Sheng-Che; Chen, Ko-Kung; Yu, Deuerling-Zheng; Wu, Chun-Hsien Frank; Liou, Jy-Kang Adrian

    2016-05-01

    Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing the penumbra in acute stroke equivalent to that of magnetic resonance perfusion (MRP). The aim of our study was to evaluate the feasibility of quantifying oligemia in the brain in patients with carotid stenosis.Ten patients with unilateral carotid stenosis of >70% were included. All MRPs and FD-CTPs were performed before stenting. Region-of-interests (ROIs) including middle cerebral artery territory at basal ganglia level on both stenotic and contralateral sides were used for quantitative analysis. Relative time to peak (rTTP) was defined as TTP of the stenotic side divided by TTP of the contralateral side, and so as relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative cerebral blood flow (rCBF). Absolute and relative TTP, CBV, MTT, CBF between two modalities were compared.For absolute quantitative analysis, the correlation of TTP was highest (r = 0.56), followed by CBV (r = 0.47), MTT (r = 0.47), and CBF (r = 0.43); for relative quantitative analysis, rCBF was the highest (r = 0.79), followed by rTTP (r = 0.75) and rCBV (r = 0.50).We confirmed that relative quantitative assessment of FD-CTP is feasible in chronic ischemic disease. Absolute quantitative measurements between MRP and FD-CTP only expressed moderate correlations. Optimization of acquisitions and algorithms is warranted to achieve better quantification. PMID:27196456

  4. Ischaemic wound complications in above-knee amputations in relation to the skin perfusion pressure

    DEFF Research Database (Denmark)

    Holstein, P

    1980-01-01

    Healing of the stumps in 59 above-knee amputations was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 131I-(-) or 125I-(-) antipyrine mixed with histamine. Out of the 11 cases with an SPP below 30 mm...... ischaemic wound complications in above-knee amputations as has previously been shown to be the case in below-knee amputations....

  5. Study of a new method for the evaluation of portal vein pressure by hepatic perfusion imaging

    International Nuclear Information System (INIS)

    To study a new method for predication of portal vein pressure (PVP) by hepatic perfusion imaging. 25 hepato-cirrhotic cases and 13 normal controls were performed the hepatic perfusion imaging. According to two compartmental model the values of portal vein indexes (PVI) was calculated using curve slope, area and hepatic heart perfusion ratio methods etc. The relationship of PVI with different method to PVP was also observed. All PVI by three methods in hepatocirrhosis were higher than those in normal controls (P<0.01), and also positively correlated with the PVP, their correlated coefficients was 0.79, 0.60, 0.68 respectively. Among them the slope method was most markedly significant than normal control and closely correlated with PVP. PVI can sensitively reflect the changes of portal vein blood flow. And it was an atraumatic, simple method for the evaluation of PVP

  6. Evaluation of cerebral perfusion in patients with neuropsychiatric systemic lupus erythematosus using 123I-IMP SPECT

    International Nuclear Information System (INIS)

    In the course of systemic lupus erythematosus (SLE), central nervous system (CNS) complications occur at a high frequency. An accurate diagnosis of CNS lupus, differentiated from secondary CNS involvement, is difficult. CNS lupus is indicative of advancing primary disease and is treated by steroid pulse therapy or increased dosage of steroids. In contrast, if symptoms are caused by secondary CNS complications, it is possible to observe or treat these complications using symptomatic therapy. We examined whether quantitative cerebral blood flow (CBF) measured using cerebral perfusion single photon emission computed tomography (SPECT) can be used to differentiate CNS lupus from secondary CNS involvement. We divided 18 SLE patients with CNS symptoms into a CNS lupus group and a non-CNS lupus group, and then compared the mean cerebral blood flow (mCBF) of each group of patients. SPECT was performed with N-isopropyl-p-[123I] iodoamphetamine (IMP), with quantitation carried out by table look-up and autoradiographic methods. The mCBF of both groups was decreased; however, the mCBF of patients with CNS lupus was significantly lower than that of non-CNS lupus patients. Quantitative CBF may provide a useful tool to distinguish CNS lupus from non-CNS lupus. (author)

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

    International Nuclear Information System (INIS)

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

  8. Behavior of vascular resistance undergoing various pressure insufflation and perfusion on decellularized lungs.

    Science.gov (United States)

    da Palma, Renata Kelly; Nonaka, Paula Naomi; Campillo, Noelia; Uriarte, Juan J; Urbano, Jessica Julioti; Navajas, Daniel; Farré, Ramon; Oliveira, Luis V F

    2016-05-01

    Bioengineering of functional lung tissue by using whole lung scaffolds has been proposed as a potential alternative for patients awaiting lung transplant. Previous studies have demonstrated that vascular resistance (Rv) could be altered to optimize the process of obtaining suitable lung scaffolds. Therefore, this work was aimed at determining how lung inflation (tracheal pressure) and perfusion (pulmonary arterial pressure) affect vascular resistance. This study was carried out using the lungs excised from 5 healthy male Sprague-Dawley rats. The trachea was cannulated and connected to a continuous positive airway pressure (CPAP) device to provide a tracheal pressure ranging from 0 to 15cmH2O. The pulmonary artery was cannulated and connected to a controlled perfusion system with continuous pressure (gravimetric level) ranging from 5 to 30cmH2O. Effective Rv was calculated by ratio of pulmonary artery pressure (PPA) by pulmonary artery flow (V'PA). Rv in the decellularized lungs scaffolds decreased at increasing V'PA, stabilizing at a pulmonary arterial pressure greater than 20cmH2O. On the other hand, CPAP had no influence on vascular resistance in the lung scaffolds after being subjected to pulmonary artery pressure of 5cmH2O. In conclusion, compared to positive airway pressure, arterial lung pressure markedly influences the mechanics of vascular resistance in decellularized lungs. PMID:26949099

  9. Perfusion measurements of the brain: using dynamic CT for the quantitative assessment of cerebral ischemia in acute stroke

    International Nuclear Information System (INIS)

    Objective: Perfusion CT has been successfully used as a functional imaging technique for the differential diagnosis of patients with hyperacute stroke. We investigated to what extent this technique can also be used for the quantitative assessment of cerebral ischemia. Methods and material: We studied linearity, spatial resolution and noise behaviour of cerebral blood flow (CBF) determination with computer simulations and phantom measurements. Statistical ROI based analysis of CBF images of a subset of 38 patients from a controlled clinical stroke study with currently more than 75 patients was done to check the power of relative cerebral blood flow (rCBF) values to predict definite infarction and ischemic penumbra. Classification was performed using follow-up CT and MR data. Results: Absolute CBF values were systematically underestimated, the degree depended on the cardiac output of the patients. Phantom measurements and simulations indicated very good linearity allowing reliable calculation of rCBF values. Infarct and penumbra areas in 19 patients receiving standard heparin therapy had mean rCBF values of 0.19 and 0.62, respectively. The corresponding values for 19 patients receiving local intraarterial fibrinolysis were 0.18 and 0.57. The difference between infarct and penumbra values was highly significant (P<0.0001) in both groups. No penumbra area was found with an rCBF value of less than 0.20. While in the heparin group only 25% of all areas with an rCBF between 0.20 and 0.35 survived, in the fibrinolytic group 61% of these areas could be saved (P<0.05). Conclusion: Perfusion CT is a fast and practical technique for routine clinical application. It provides substantial and important additional information for the selection of the optimal treatment strategy for patients with hyperacute stroke. Relative values of cerebral blood flow discriminate very well between areas of reversible and irreversible ischemia; an rCBF value of 0.20 appears to be a definite lower

  10. High frequency jet ventilation and intermittent positive pressure ventilation. Effect of cerebral blood flow in patients after open heart surgery

    International Nuclear Information System (INIS)

    Attenuation of ventilator-synchronous pressure fluctuations of intracranial pressure has been demonstrated during high frequency ventilation in animal and human studies, but the consequences of this effect on cerebral blood flow have not been investigated in man. We compared the effects of high frequency jet ventilation and intermittent positive pressure ventilation on CBF in 24 patients investigated three hours after completion of open-heart surgery. The patients were investigated during three consecutive periods with standard sedation (morphine, pancuronium): a. IPPV; b. HFJV; c. IPPV. Partial pressure of arterial CO2 (PaCO2: 4.5-5.5 kPa) and rectal temperature (35.5 to 37.5 degree C) were maintained constant during the study. The CBF was measured by intravenous 133Xe washout technique. The following variables were derived from the cerebral clearance of 133Xe: the rapid compartment flow, the initial slope index, ie, a combination of the rapid and the slow compartment flows, and the ratio of fast compartment flow over total CBF (FF). Compared to IPPV, HFJV applied to result in the same mean airway pressure did not produce any change in pulmonary gas exchange, mean systemic arterial pressure, and cardiac index. Similarly, CBF was not significantly altered by HFJV. However, important variations of CBF values were observed in three patients, although the classic main determinants of CBF (PaCO2, cerebral perfusion pressure, Paw, temperature) remained unchanged. Our results suggest that in patients with normal systemic hemodynamics, the effects of HFJV and IPPV on CBF are comparable at identical levels of mean airway pressure

  11. Parametric quantification of changes in cerebral perfusion caused by withdrawal and neurocognitive activation in cocaine-dependent

    International Nuclear Information System (INIS)

    Introduction: Cocaine-dependent subjects might have socially disruptive behavior. Several regional cerebral blood flow (rCBF) abnormalities have been described in these patients, mainly in the prefrontal cortex, area related to executive functions and impulse control. Wisconsin Card Sorting Test (WCST) was specifically designed to activate this cortical area. Aim: To quantify rCBF and to assess prefrontal activation pre and post detoxification on cocaine-dependant subjects. Methods: We studied 23 patients who met DSM-IV criteria for cocaine dependency ranging from 24 - 49 years old (19 males), all with positive urine cocaine test. Baseline 99mTc-ECD brain perfusion SPECT was performed at admission and after 4 weeks of controlled in-hospital abstinence; in 19 patients SPECT was acquired also after WCST activation. Statistical Parametric Mapping (SPM) was used to compare SPECT studies on these 4 conditions. Results: rCBF of bilateral parieto-occipital area, left prefrontal cortex and multiple small cortical region improved after 4 weeks of cocaine detoxification. The group analysis did not show significant prefrontal cortex activation induced by WCST on admission. After 4 weeks of strict cocaine abstinence, WCST was able to induce left dorsolateral prefrontal cortex activation. Conclusions: A month of strict cocaine abstinence improved brain perfusion in dependant patients. After recent consumption, there was no prefrontal activation when using WCST, but this was observed after abstinence, supporting neurocognitive improvement. These findings may have clinical implications as potential predictors of therapy response

  12. The Application of Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Therapy of Acute Cerebral Infarction

    Directory of Open Access Journals (Sweden)

    Jianping Dai

    2006-10-01

    Full Text Available Diffusion- and perfusion-weighted magnetic resonance imaging (DWI and PWI was applied for stroke diagnose in 120 acute (<48 h ischemic stroke patients. At hyperacute (<6 h stage, it is difficult to find out the infarction zone in conventional T1 or T2 image, but it is easy in DWI, apparent diffusion coefficient (ADC map; when at 3–6-hour stage it is also easy in PWI, cerebral blood flow (CBF map, cerebral blood volume (CBV map, and mean transit time (MTT map; at acute (6–48 h stage, DWI or PWI is more sensitive than conventional T1 or T2 image too. Combining DWI with ADC, acute and chronic infarction can be distinguished. Besides, penumbra which should be developed in meaning was used as an indication or to evaluate the therapeutic efficacy. There were two cases (<1.5 h that broke the model of penumbra because abnormity was found in DWI but not that in PWI, finally they recovered without any sequela.

  13. Optimal location for arterial input function measurements near the middle cerebral artery in first-pass perfusion MRI.

    Science.gov (United States)

    Bleeker, Egbert J W; van Buchem, Mark A; van Osch, Matthias J P

    2009-04-01

    One of the main difficulties in obtaining quantitative perfusion values from dynamic susceptibility contrast-magnetic resonance imaging is a correct arterial input function (AIF) measurement, as partial volume effects can lead to an erroneous shape and amplitude of the AIF. Cerebral blood flow and volume scale linearly with the area under the AIF, but shape changes of the AIF can lead to large, nonlinear errors. Current manual and automated AIF selection procedures do not guarantee the exclusion of partial volume effects from AIF measurements. This study uses a numerical model, validated by phantom experiments, for predicting the optimal location for AIF measurements in the vicinity of the middle cerebral artery (MCA). Three different sequences were investigated and evaluated on a voxel-by-voxel basis by comparison with the ground truth. Subsequently, the predictions were evaluated in an in vivo example. The findings are fourfold: AIF measurements should be performed in voxels completely outside the artery, here a linear relation should be assumed between DeltaR*2 and the concentration contrast agent, the exact optimal location differs per acquisition type, and voxels including a small MCA yield also correct AIF measurements for segmented echo planar imaging when a short echo time was used. PMID:19142193

  14. Improvements in the technique of vascular perfusion-fixation employing a fluorocarbon-containing perfusate and a peristaltic pump controlled by pressure feedback

    DEFF Research Database (Denmark)

    Rostgaard, J; Qvortrup, K; Poulsen, Steen Seier

    1993-01-01

    elements. By adding oxygenated fluorocarbon to glutaraldehyde perfusate-fixatives, enough oxygen is made accessible for cellular respiration as well as for the oxygen-consuming chemical reactions of glutaraldehyde with the tissue. Data on anaesthesia, operative manoeuvres, mechanical components of the......A new improved technique for whole-body perfusion-fixation of rats and other small animals is described. The driving force is a peristaltic pump which is feedback regulated by a pressure transducer that monitors the blood-perfusion pressure in the left ventricle of the heart. The primary perfusate-fixative...... is composed of a blood substitute--13.3% oxygenated fluorocarbon FC-75--in 0.05 M cacodylate buffer (pH 7.4) with a 2% glutaraldehyde. The secondary perfusate-fixative is composed of 2% glutaraldehyde in 0.05 M cacodylate buffer (pH 7.4) with 20 mM CaCl2. A double-barrelled, self-holding cannula is...

  15. DOES MEAN PERFUSION PRESSURE DURING CARDIOPULMONARY BYPASS AFFECT RENAL FUNCTION?

    Directory of Open Access Journals (Sweden)

    Ramesh

    2015-10-01

    Full Text Available BACKGROUND: After cardiac surgery acute kidney injury (AKI is a common and serious condition carrying significant costs and is independently associated with increased morbidity and mortality. During cardiopulmonary bypass (CPB surgery, modifiable factors may contri bute to post - operative AKI. Their prevention might be a potential target for nephroprotection and any other morbidity after cardiac surgery. METHODS AND MATERIAL : The objective of the present study was to identify and determine whether intraoperative hypot ension or any other cofactor are independent risk factors for postoperative AKI defined by the RIFLE (renal Risk, Injury, Failure, Loss of renal function and End - stage renal disease. On basis of this patients were divided into two groups according to rise in serum creatinine >0.3 mg/dl till 72 hrs postoperatively. Group B patients have developed AKI (n=34 and the remaining patients were in Group A. RESULT : In our study we have found that mean arterial pressure during CPB were less in group B patients compare to group A patients which was statistically significant (p<0.001. And in this group ICU stay and mortality rate were also high compare to group A pati ent who had not developed AKI. CONCLUSION: Lower MAP during CPB is associated with development of postoperative renal derangement, leads to increase ICU stay and mortality. Larger studies are required to further support the evidence

  16. Cerebral perfusion and cerebrovascular reactivity are reduced in white matter hyperintensities

    DEFF Research Database (Denmark)

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

    2002-01-01

    reported global reductions in cerebral blood flow (CBF) and cerebral vascular reactivity. In this study, we examined localized hemodynamic status to compare WMH to normal appearing white matter (NAWM). METHODS: A group of 21 normal 85-year-old subjects were studied using dynamic contrast-enhanced MRI...... NAWM (P=0.026, P<0.001). CONCLUSION: These results show that a change in the hemodynamic status is present within the WMH, making these areas more likely to be exposed to transient ischemia inducing myelin rarefaction. In the future, MRI may be used to examine the effect of therapeutic strategies...

  17. Reduction in cerebral perfusion after heroin administration: a resting state arterial spin labeling study.

    Directory of Open Access Journals (Sweden)

    Niklaus Denier

    Full Text Available Heroin dependence is a chronic relapsing brain disorder, characterized by the compulsion to seek and use heroin. Heroin itself has a strong potential to produce subjective experiences characterized by intense euphoria, relaxation and release from craving. The neurofunctional foundations of these perceived effects are not well known. In this study, we have used pharmacological magnetic resonance imaging (phMRI in 15 heroin-dependent patients from a stable heroin-assisted treatment program to observe the steady state effects of heroin (60 min after administration. Patients were scanned in a cross-over and placebo controlled design. They received an injection of their regular dose of heroin or saline (placebo before or after the scan. As phMRI method, we used a pulsed arterial spin labeling (ASL sequence based on a flow-sensitive alternating inversion recovery (FAIR spin labeling scheme combined with a single-shot 3D GRASE (gradient-spin echo readout on a 3 Tesla scanner. Analysis was performed with Statistical Parametric Mapping (SPM 8, using a general linear model for whole brain comparison between the heroin and placebo conditions. We found that compared to placebo, heroin was associated with reduced perfusion in the left anterior cingulate cortex (ACC, the left medial prefrontal cortex (mPFC and in the insula (both hemispheres. Analysis of extracted perfusion values indicate strong effect sizes and no gender related differences. Reduced perfusion in these brain areas may indicate self- and emotional regulation effects of heroin in maintenance treatment.

  18. Low pulmonary artery flush perfusion pressure combined with high positive end-expiratory pressure reduces oedema formation in isolated porcine lungs

    International Nuclear Information System (INIS)

    Flush perfusion of the pulmonary artery with organ protection solution is a standard procedure before lung explantation. However, rapid flush perfusion may cause pulmonary oedema which is deleterious in the lung transplantation setting. In this study we tested the hypotheses that high pulmonary perfusion pressure contributes to the development of pulmonary oedema and positive end-expiratory pressure (PEEP) counteracts oedema formation. We expected oedema formation to increase weight and decrease compliance of the lungs on the basis of a decrease in alveolar volume as fluid replaces alveolar air spaces. The pulmonary artery of 28 isolated porcine lungs was perfused with a low-potassium dextrane solution at low (mean 27 mmHg) or high (mean 40 mmHg) pulmonary artery pressure (PAP) during mechanical ventilation at low (4 cmH2O) or high (8 cmH2O) PEEP, respectively. Following perfusion and storage, relative increases in lung weight were smaller (p < 0.05) during perfusion at low PAP (62 ± 32% and 42 ± 26%, respectively) compared to perfusion at high PAP (133 ± 54% and 87 ± 30%, respectively). Compared to all other PAP–PEEP combinations, increases in lung weight were smallest (44 ± 9% and 27 ± 12%, respectively), nonlinear intratidal lung compliance was largest (46% and 17% respectively, both p < 0.05) and lung histology showed least infiltration of mononuclear cells in the alveolar septa, and least alveolar destruction during the combination of low perfusion pressure and high PEEP. The findings suggest that oedema formation during pulmonary artery flush perfusion in isolated and ventilated lungs can be reduced by choosing low perfusion pressure and high PEEP. PAP–PEEP titration to minimize pulmonary oedema should be based on lung mechanics and PAP monitoring

  19. Surfactant bolus instillation: effects of different doses on blood pressure and cerebral blood flow velocities

    OpenAIRE

    Rey, M.; Segerer, Hugo; Kiessling, C.; Obladen, Michael

    1994-01-01

    Fifteen preterm infants suffering from respiratory distress syndrome were randomly allocated to receive either high-dose (200 mg/kg) or low-dose (100 mg/kg) surfactant treatment. Retreatments were done with the low dose. Blood pressure, blood gases and cerebral blood flow velocities were determined before and after 24 bolus instillations. With the high dose mean blood pressure and mean cerebral blood flow velocity dropped significantly. With the low dose only mean cerebral blood flow velocity...

  20. Prediction of Cerebral Hyperperfusion Syndrome with Velocity Blood Pressure Index

    Directory of Open Access Journals (Sweden)

    Zhi-Chao Lai

    2015-01-01

    Full Text Available Background: Cerebral hyperperfusion syndrome is an important complication of carotid endarterectomy (CEA. An >100% increase in middle cerebral artery velocity (MCAV after CEA is used to predict the cerebral hyperperfusion syndrome (CHS development, but the accuracy is limited. The increase in blood pressure (BP after surgery is a risk factor of CHS, but no study uses it to predict CHS. This study was to create a more precise parameter for prediction of CHS by combined the increase of MCAV and BP after CEA. Methods: Systolic MCAV measured by transcranial Doppler and systematic BP were recorded preoperatively; 30 min postoperatively. The new parameter velocity BP index (VBI was calculated from the postoperative increase ratios of MCAV and BP. The prediction powers of VBI and the increase ratio of MCAV (velocity ratio [VR] were compared for predicting CHS occurrence. Results: Totally, 6/185 cases suffered CHS. The best-fit cut-off point of 2.0 for VBI was identified, which had 83.3% sensitivity, 98.3% specificity, 62.5% positive predictive value and 99.4% negative predictive value for CHS development. This result is significantly better than VR (33.3%, 97.2%, 28.6% and 97.8%. The area under the curve (AUC of receiver operating characteristic: AUC VBI = 0.981, 95% confidence interval [CI] 0.949-0.995; AUC VR = 0.935, 95% CI 0.890-0.966, P = 0.02. Conclusions: The new parameter VBI can more accurately predict patients at risk of CHS after CEA. This observation needs to be validated by larger studies.

  1. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    Directory of Open Access Journals (Sweden)

    Anne-SophieG.T.Bronzwaer

    2014-04-01

    Full Text Available Rationale:\tA critical reduction in central blood volume (CBV is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV. Stroke volume index (SVI serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI and regional brain perfusion during CBV depletion and repletion in spontaneously breathing volunteers. Methods: This study quantified in 14 healthy subjects (11 male the effects of CBV depletion (by 30 and 70 degrees passive head-up tilt (HUT and a fluid challenge (by tilt back on CBV (thoracic admittance, mean middle cerebral artery (MCA blood flow velocity (Vmean, SVI, cardiac index (CI , PPV and SPV. Results: PPV (103±89%, p< 0.05 and SPV (136±117%, p< 0.05 increased with progression of central hypovolemia manifested by a reduction in thoracic admittance (11±5%, p< 0.001, SVI (28±6%, p< 0.001, CI (6±8%, p< 0.001 and MCAVmean (17±7%, p< 0.05 but not in arterial pressure. The reduction in MCAVmean correlated to the fall in SVI (R2=0.52, p< 0.0001 and inversely to PPV and SPV (R2=0.46 (p< 0.0001 and R2=0.45 (p< 0.0001, respectively. PPV and SPV predicted a ≥15% reduction in MCAVmean and SVI with comparable sensitivity (67%/ 67% vs. 63%/ 68% respectively and specificity (89%/94% vs. 89%/94%, respectively. A rapid fluid challenge by tilt-back restored all parameters to baseline values within one minute. Conclusion: In spontaneously breathing subjects, a reduction in MCAVmean was related to an increase in PPV and SPV during graded CBV depletion and repletion. Specifically, PPV and SPV predicted changes in both SVI and MCAVmean with comparable sensitivity and specificity, however the predictive value is limited in spontaneously breathing subjects.

  2. Cerebral perfusion scintigraphy and the exploration of dementia syndromes: An illustration with five clinical cases

    International Nuclear Information System (INIS)

    The epidemiological evidence suggests that individuals with higher education level have a reduced risk of developing dementia. Because cognitive reserve and its compensation mechanisms may modulate the clinical expression in neuro-degenerative pathology, it is important to study subjects who present mild cognitive disturbance with functional imaging. The cerebral SPECT has been used to determine regional uptake of radiotracer into the brain of patients with cognitive impairment. These abnormalities of blood flow were correlated with cognitive impairment. The cerebral SPECT is also useful to investigate preclinical dementia and to predict the evolution of cognitive disturbance. This article, reports some technical and semeiological notions and illustrate with five clinical cases the scintigraphic aspect of some dementia syndrome. (authors)

  3. Association of frontal gray matter volume and cerebral perfusion in heroin addiction: A multimodal neuroimaging study

    OpenAIRE

    StefanBorgwardt; Ernst-WilhelmRadue

    2013-01-01

    Structure and function are closely related in the healthy human brain. In patients with chronic heroin exposure, brain imaging studies have identified long-lasting changes in gray matter (GM) volume. More recently, we showed that acute application of heroin in dependent patients results in hypoperfusion of fronto-temporal areas compared with the placebo condition. However, the relationship between structural and cerebral blood flow (CBF) changes in heroin addiction has not yet been investigat...

  4. Reduced cerebral perfusion on sudden immersion in ice water: a possible cause of drowning

    DEFF Research Database (Denmark)

    Mantoni, Teit; Belhage, Bo; Pedersen, Lars M;

    2007-01-01

    Near-drowning incidents and drowning deaths after accidental immersion in open waters have been linked to cold shock response. It consists of inspiratory gasps, hyperventilation, tachycardia, and hypertension in the first 2-3 min of cold-water immersion. This study explored the immediate changes in...... cerebral blood flow velocity (Vmean) during cold-water immersion since cold shock induced hyperventilation may diminish Vmean and lead to syncope and drowning....

  5. Cerebral Perfusion and Aortic Stiffness Are Independent Predictors of White Matter Brain Atrophy in Type 1 Diabetic Patients Assessed With Magnetic Resonance Imaging

    OpenAIRE

    van Elderen, Saskia G. C.; Brandts, Anne; van der Grond, Jeroen; Westenberg, Jos J. M.; Kroft, Lucia J.M.; van Buchem, Mark A.; Smit, Johannes W.A.; de Roos, Albert

    2011-01-01

    OBJECTIVE To identify vascular mechanisms of brain atrophy in type 1 diabetes mellitus (DM) patients by investigating the relationship between brain volumes and cerebral perfusion and aortic stiffness using magnetic resonance imaging (MRI). RESEARCH DESIGN AND METHODS Approval from the local institutional review board was obtained, and patients gave informed consent. Fifty-one type 1 DM patients (30 men; mean age 44 ± 11 years; mean DM duration 23 ± 12 years) and 34 age- and sex-matched healt...

  6. Characteristic pattern of cerebral perfusion in patients with the early stage of subcortical vascular dementia compared with Alzheimer's disease

    International Nuclear Information System (INIS)

    Brain perfusion SPECT has been commonly used to evaluate several different types of dementia. The aim of this study is to assess the specific patterns of regional cerebral blood flow (rCBF) in patients with the early stage of subcortical vascular dementia (SVD) and Alzheimer's disease (AD) using Tc-99m HMPAO SPECT, and to compare the differences between the two conditions. Sixteen SVD (mean age; 68.0±7.0 years, educational period; 6.3±5.6 years, CDR; 0.80±0.26). 46 AD (mean age; 69.9±7.4 years, educational period; 5.4±4.7 years, CDR; 0.86±0.23) and 12 normal control subjects (mean age; 67.1±7.7 years, educational period; 6.2±4.2 years) participated in this study. We included the patients with SVD and AD according to NINCDS-ADRDA criteria for probable AD and NINDS-AIREN criteria for probable or possible VD. They were all matched for age, education and clinical dementia scale scores. SPM analysis of the SPECT image showed significant perfusion deficits on the right temporal region and right thalamus, left insula and superior temporal gyrus, both cingulate gyri and frontal subgyral regions in patients with SVD and on the left supramarginal gyrus, superior temporal gyrus, postcentral gyrus and inferior parietal lobule, right fugiform gyrus and both cingulate gyri in patients with AD compared with control subjects (uncorrected p<0.01). SVD patients revealed significant hypoperfusion in the right parahippocampal gyrus, right cingulated gyrus, left insula, and both frontal subgyral regions compared with AD patients (uncorrected p<0.01). SVD patients revealed significant hyperperfusion in right superior frontal gyrus, left pre- and postcentral gyri, left paracentral lobule, left precuneus and both medial frontal gyri compared with AD patients (uncorrected p<0.01). Our study shows characteristic and different pattern of perfusion deficits in patients with SVD and AD, and these results may be helpful to discriminate the two conditions in the early stage of illness

  7. 3-Fluoro-Deoxyglucose for the assessment of cerebral perfusion and glucose transport - Indications for extracranial-intracranial arterial bypass and followup studies

    International Nuclear Information System (INIS)

    3-Fluor-Deoxyglucose (3FDG) is a glucose-analogue which is transported across the blood-brain-barrier by the same carrier as glucose but is only phoshorylated to a minor part. By a newly developed model, it became possible to estimate both cerebral perfusion and glucose transport in a single examination, determining the Michaelis-Menten-constant K/sub M/ and the maximal velocity v/sub m/. Normal values were determined as follows: gray matter perfusion 88+-8 ml/ 100g min; v/sub m/ was 2.46 μmol/g min; K/sub M/ was 6.42 μmol/g. This method was applied successfully in a series of 15 patients with cerebral ischemia to select suitable candidates for extacranial-intracranial (EC-IC) arterial bypass surgery and to follow them up to 15 months postop. In patients with minor strokes and transient ischemic attacks (TIA), areas which appeared normal in conventional CT presented with reduced perfusion values (down to 67 ml/ 100 g min) and either normal or reduced v/sub m/ (down to 0.8 μmol/g min). These patients were thought optimal candidates for EC-IC bypass in order to improve the misery perfusion rate

  8. Structural and Perfusion Abnormalities of Brain on MRI and Technetium-99m-ECD SPECT in Children With Cerebral Palsy: A Comparative Study.

    Science.gov (United States)

    Rana, Kamer Singh; Narwal, Varun; Chauhan, Lokesh; Singh, Giriraj; Sharma, Monica; Chauhan, Suneel

    2016-04-01

    Cerebral palsy has traditionally been associated with hypoxic ischemic brain damage. This study was undertaken to demonstrate structural and perfusion brain abnormalities. Fifty-six children diagnosed clinically as having cerebral palsy were studied between 1 to 14 years of age and were subjected to 3 Tesla magnetic resonance imaging (MRI). Brain and Technetium-99m-ECD brain single-photon emission computed tomography (SPECT) scan. Male to female ratio was 1.8:1 with a mean age of 4.16 ± 2.274 years. Spastic cerebral palsy was the most common type, observed in 91%. Birth asphyxia was the most common etiology (69.6%). White matter changes (73.2%) such as periventricular leukomalacia and corpus callosal thinning were the most common findings on MRI. On SPECT all cases except one revealed perfusion impairments in different regions of brain. MRI is more sensitive in detecting white matter changes, whereas SPECT is better in detecting cortical and subcortical gray matter abnormalities of perfusion. PMID:26353878

  9. Early Effects of Combretastatin-A4 Disodium Phosphate on Tumor Perfusion and Interstitial Fluid Pressure

    Directory of Open Access Journals (Sweden)

    Carsten D. Ley

    2007-02-01

    Full Text Available Combretastatin-A4 disodium phosphate (CA4DP is a vascular-disruptive agent that causes an abrupt decrease in tumor blood flow. The direct actions of CA4DP include increases in vascular permeability and destabilization of the endothelial cytoskeleton, which are thought to contribute to occlusion of the tumor vasculature. It has been proposed that increased permeability causes a transient increase in interstitial fluid pressure (IFP, which in turn could collapse intratumoral blood vessels. We examined the immediate effects of CA4DP on tumor IFP in C3H mammary carcinoma. Mice were treated with 100 mg/kg CA4DP by intraperitoneal injection. Tumor perfusion was recorded by laser Doppler flowmetry at separate time points, and IFP was recorded continuously by the wickin-needle method. In this study, we found that CA4DP treatment resulted in a rapid reduction in tumor perfusion, followed by a decrease in IFP; no increases in IFP were observed. This suggests that CA4DP-induced reductions in tumor perfusion are not dependent on increases in IFP.

  10. SPECT imaging of GABA{sub A}/benzodiazepine receptors and cerebral perfusion in mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Pappata, Sabina; Varrone, Andrea; Vicidomini, Caterina; Sansone, Valeria; Comerci, Marco; Panico, Maria Rosaria; Quarantelli, Mario [CNR, Institute of Biostructure and Bioimaging, Naples (Italy); Milan, Graziella; De Falco, Caterina; Lore, Elisa; Postiglione, Alfredo [University ' ' Federico II' ' , Department of Clinical and Experimental Medicine, Naples (Italy); Iavarone, Alessandro [Neurologic and Stroke Unit, CTO Hospital, Naples (Italy); Salvatore, Marco [CNR, Institute of Biostructure and Bioimaging, Naples (Italy); University ' ' Federico II' ' , Department of Biomorphological and Functional Sciences, Naples (Italy)

    2010-06-15

    The involvement of neocortical and limbic GABA{sub A}/benzodiazepine (BZD) receptors in Alzheimer's disease (AD) is controversial and mainly reported in advanced stages. The status of these receptors in the very early stages of AD is unclear and has not been explored in vivo. Our aims were to investigate in vivo the integrity of cerebral cortical GABA{sub A}/BZD receptors in subjects with amnestic mild cognitive impairment (MCI) and to compare possible receptor changes to those in cerebral perfusion. [{sup 123}I]Iomazenil and [{sup 99m}Tc]HMPAO SPECT images were acquired in 16 patients with amnestic MCI and in 14 normal elderly control subjects (only [{sup 123}I]iomazenil imaging in 5, only [{sup 99m}Tc]HMPAO imaging in 4, and both [{sup 123}I]iomazenil and [{sup 99m}Tc]HMPAO imaging in 5). Region of interest (ROI) analysis and voxel-based analysis were performed with cerebellar normalization. Neither ROI analysis nor voxel-based analysis showed significant [{sup 123}I]iomazenil binding changes in MCI patients compared to control subjects, either as a whole group or when considering only those patients with MCI that converted to AD within 2 years of clinical follow-up. In contrast, the ROI analysis revealed significant hypoperfusion of the precuneus and posterior cingulate cortex in the whole group of MCI patients and in MCI converters as compared to control subjects. Voxel-based analysis showed similar results. These results indicate that in the very early stages of AD, neocortical and limbic neurons/synapses expressing GABA{sub A}/BZD receptors are essentially preserved. They suggest that in MCI patients functional changes precede neuronal/synaptic loss in neocortical posterior regions and that [{sup 99m}Tc]HMPAO rCBF imaging is more sensitive than [{sup 123}I]iomazenil GABA{sub A}/BZD receptor imaging in detecting prodromal AD. (orig.)

  11. Near-infrared spectroscopy monitoring of cerebral oxygen during assisted ventilation

    OpenAIRE

    Booth, Erin A.; Dukatz, Christopher; Sood, Beena G.; Wider, Michael

    2011-01-01

    Background: Changes in the arterial partial pressure of CO2 (PaCO2) has a direct though transient effect on the cerebral vasculature and cerebral circulation. Decreased PaCO2 levels lead to vasoconstriction and can result in dangerously low levels of cerebral perfusion that resolve in 4–6 h. It is currently believed that perfusion abnormalities contribute to intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) in the neonate. PaCO2-induced vasoconstriction may contribute t...

  12. Cutaneous vasoconstriction affects near-infrared spectroscopy determined cerebral oxygen saturation during administration of norepinephrine

    DEFF Research Database (Denmark)

    Sørensen, Niels Henrik Breiner; Secher, Niels H; Siebenmann, Christoph;

    2012-01-01

    Perioperative optimization of spatially resolved near-infrared spectroscopy determined cerebral frontal lobe oxygenation (scO2) may reduce postoperative morbidity. Norepinephrine is routinely administered to maintain cerebral perfusion pressure and, thereby, cerebral blood flow, but norepinephrine...... reduces the scO2. We hypothesized that norepinephrine-induced reduction in scO2 is influenced by cutaneous vasoconstriction....

  13. Effects of renal pelvic high-pressure perfusion on nephrons in a porcine pyonephrosis model

    OpenAIRE

    Wang, Jian; ZHOU, DA-QING; He, Meng; Li, Wen-Gang; PANG, XIANG; YU, XIAO-XIANG; Jiang, Bo

    2013-01-01

    The aim of this study was to investigate the effects of various renal pelvic pressure gradients on nephrons with purulent infection. Five miniature test pigs were selected. One side of the kidney was used to prepare the pyonephrosis model and the other side was used as the healthy control. A piezometer and a water fill tube were inserted into the renal pelvis through the ureter. Prior to perfusion, punctures were made on the healthy and purulent sides of the kidneys to obtain tissues (as cont...

  14. Wavelet-based calculation of cerebral angiographic data from time-resolved CT perfusion acquisitions

    Energy Technology Data Exchange (ETDEWEB)

    Havla, Lukas; Dietrich, Olaf [Ludwig-Maximilians-University Hospital Munich, Josef-Lissner-Laboratory for Biomedical Imaging, Institute for Clinical Radiology, Munich (Germany); Thierfelder, Kolja M.; Beyer, Sebastian E.; Sommer, Wieland H. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany)

    2015-08-15

    To evaluate a new approach for reconstructing angiographic images by application of wavelet transforms on CT perfusion data. Fifteen consecutive patients with suspected stroke were examined with a multi-detector CT acquiring 32 dynamic phases (∇t = 1.5s) of 99 slices (total slab thickness 99mm) at 80kV/200mAs. Thirty-five mL of iomeprol-350 was injected (flow rate = 4.5mL/s). Angiographic datasets were calculated after initial rigid-body motion correction using (a) temporally filtered maximum intensity projections (tMIP) and (b) the wavelet transform (Paul wavelet, order 1) of each voxel time course. The maximum of the wavelet-power-spectrum was defined as the angiographic signal intensity. The contrast-to-noise ratio (CNR) of 18 different vessel segments was quantified and two blinded readers rated the images qualitatively using 5pt Likert scales. The CNR for the wavelet angiography (501.8 ± 433.0) was significantly higher than for the tMIP approach (55.7 ± 29.7, Wilcoxon test p < 0.00001). Image quality was rated to be significantly higher (p < 0.001) for the wavelet angiography with median scores of 4/4 (reader 1/reader 2) than the tMIP (scores of 3/3). The proposed calculation approach for angiography data using temporal wavelet transforms of intracranial CT perfusion datasets provides higher vascular contrast and intrinsic removal of non-enhancing structures such as bone. (orig.)

  15. Relationship between regional cerebral perfusion and cognitive disorders in type 2 diabetes mellitus

    International Nuclear Information System (INIS)

    Objective: To investigate the characteristic rCBF abnormalities and the relationship between rCBF and cognitive disorders in type 2 diabetes mellitus patients. Methods: The study subjects were 11 middle aged, glycemic controlled type 2 diabetes mellitus patients. Age range of type 2 diabetes mellitus patients was 46 - 59 years. Eleven age-, sex-, education- and occupation- matched normal controls (age range 41 - 58 years) were studied under identical conditions. Cognitive functions were evaluated by Wechsler Memory Scale (WMS), Trail Marking Test A and Wisconsin Card Sorting Test (WCST), respectively. 99Tcm-ECD (ethyl-cysteine ate dimer) SPECT imaging was performed on all patients and normal controls. Results: 1) Cognitive test scores of type 2 diabetes mellitus patients were lower than that of normal controls. Diabetic patients were scored lower in memory test than controls (accumulation adding, visual recognition, learning and total memory quotient of WMS, P < 0.05). Type 2 diabetes mellitus patients needed much more time to complete the trail marking test (74.2 s vs. 48.7 s). WCST scores were significantly different between two groups. 2) The rCBF values of frontal, temporal and parietal lobe were decreased significantly in type 2 diabetes mellitus patients. 3) For type 2 diabetes mellitus patients, there was a correlation between rCBF values of right frontal lobe and adding, understanding scores of WMS (positively correlated), preservative errors(%) of WCST (negatively correlated). The rCBF values of right temporal lobe were positively correlated with inverted counting. Conclusions: 1) Impairments of central nervous system are existed in glycemic controlled (lack of repeated hypoglycemia) type 2 diabetes mellitus patients. Abnormalities in CNS can express as cognitive dysfunction, such as decrement of memory, attention, thinking and conceptual reasoning abilities. 2) Hypo-perfusions of frontal, temporal and parietal cortex can be identified in patients of

  16. Wavelet-based calculation of cerebral angiographic data from time-resolved CT perfusion acquisitions

    International Nuclear Information System (INIS)

    To evaluate a new approach for reconstructing angiographic images by application of wavelet transforms on CT perfusion data. Fifteen consecutive patients with suspected stroke were examined with a multi-detector CT acquiring 32 dynamic phases (∇t = 1.5s) of 99 slices (total slab thickness 99mm) at 80kV/200mAs. Thirty-five mL of iomeprol-350 was injected (flow rate = 4.5mL/s). Angiographic datasets were calculated after initial rigid-body motion correction using (a) temporally filtered maximum intensity projections (tMIP) and (b) the wavelet transform (Paul wavelet, order 1) of each voxel time course. The maximum of the wavelet-power-spectrum was defined as the angiographic signal intensity. The contrast-to-noise ratio (CNR) of 18 different vessel segments was quantified and two blinded readers rated the images qualitatively using 5pt Likert scales. The CNR for the wavelet angiography (501.8 ± 433.0) was significantly higher than for the tMIP approach (55.7 ± 29.7, Wilcoxon test p < 0.00001). Image quality was rated to be significantly higher (p < 0.001) for the wavelet angiography with median scores of 4/4 (reader 1/reader 2) than the tMIP (scores of 3/3). The proposed calculation approach for angiography data using temporal wavelet transforms of intracranial CT perfusion datasets provides higher vascular contrast and intrinsic removal of non-enhancing structures such as bone. (orig.)

  17. Long-term effects of cerebral hypoperfusion on neural density and function using misery perfusion animal model

    Science.gov (United States)

    Nishino, Asuka; Tajima, Yosuke; Takuwa, Hiroyuki; Masamoto, Kazuto; Taniguchi, Junko; Wakizaka, Hidekatsu; Kokuryo, Daisuke; Urushihata, Takuya; Aoki, Ichio; Kanno, Iwao; Tomita, Yutaka; Suzuki, Norihiro; Ikoma, Yoko; Ito, Hiroshi

    2016-01-01

    We investigated the chronic effects of cerebral hypoperfusion on neuronal density and functional hyperemia using our misery perfusion mouse model under unilateral common carotid artery occlusion (UCCAO). Neuronal density evaluated 28 days after UCCAO using [11C]flumazenil-PET and histology indicated no neurologic deficit in the hippocampus and neocortex. CBF response to sensory stimulation was assessed using laser-Doppler flowmetry. Percentage changes in CBF response of the ipsilateral hemisphere to UCCAO were 18.4 ± 3.0%, 6.9 ± 2.8%, 6.8 ± 2.3% and 4.9 ± 2.4% before, and 7, 14 and 28 days after UCCAO, respectively. Statistical significance was found at 7, 14 and 28 days after UCCAO (P < 0.01). Contrary to our previous finding (Tajima et al. 2014) showing recovered CBF response to hypercapnia on 28 days after UCCAO using the same model, functional hyperemia was sustained and became worse 28 days after UCCAO. PMID:27116932

  18. Perfusion computed tomography of intracranial meningiomas: In vivo correlation of cerebral blood volume and vascular permeability

    Science.gov (United States)

    Granata, Francesca; Morabito, Rosa; Alafaci, Concetta; Barresi, Valeria; Tomasello, Francesco; Vinci, Sergio; Calamuneri, Alessandro; Grasso, Giovanni; Salpietro, Francesco Maria; Longo, Marcello

    2015-01-01

    Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour were obtained. Two correspondent regions of interest (ROIs) were drawn on CBV and PS maps. Central and peripheral CBV and PS mean values were calculated. PCT parameters were correlated to CD-34 and endoglin. Results There was a positive correlation between PS and CD-34. No correlation was found between PS values and endoglin, CBV values and CD-34 and endoglin values. Conclusion Our findings suggest that PCT may support conventional morphological imaging in predicting meningioma grading before surgery. PMID:26246100

  19. Improving cerebral blood flow quantification for arterial spin labeled perfusion MRI by removing residual motion artifacts and global signal fluctuations.

    Science.gov (United States)

    Wang, Ze

    2012-12-01

    Denoising is critical to improving the quality and stability of cerebral blood flow (CBF) quantification in arterial spin labeled (ASL) perfusion magnetic resonance imaging (MRI) due to the intrinsic low signal-to-noise-ratio (SNR) of ASL data. Previous studies have been focused on reducing the spatial or temporal noise using standard filtering techniques, and less attention has been paid to two global nuisance effects, the residual motion artifacts and the global signal fluctuations. Since both nuisances affect the whole brain, removing them in advance should enhance the CBF quantification quality for ASL MRI. The purpose of this paper was to assess this potential benefit. Three methods were proposed to suppress each or both of the two global nuisances. Their performances for CBF quantification were validated using ASL data acquired from 13 subjects. Evaluation results showed that covarying out both global nuisances significantly improved temporal SNR and test-retest stability of CBF measurement. Although the concept of removing both nuisances is not technically novel per se, this paper clearly showed the benefits for ASL CBF quantification. Dissemination of the proposed methods in a free ASL data processing toolbox should be of interest to a broad range of ASL users. PMID:22789842

  20. [Abnormal cerebral blood flow distributions during the post-ictal phase of febrile status epilepticus in three pediatric patients measured by arterial spin labeling perfusion MRI].

    Science.gov (United States)

    Hirano, Keiko; Fukuda, Tokiko

    2016-05-01

    The ability to visualize brain perfusion is important for identifying epileptic foci. We present three pediatric cases showing asymmetrical cerebral blood flow (CBF) distributions during the post-ictal phase of febrile status epilepticus measured by arterial spin labeling (ASL) perfusion MRI. During the acute phase, regional CBF measurements in the areas considered including epileptic foci were higher than in the corresponding area of the contralateral hemisphere, though the exact quantitative value varied between cases. We could not identify the correct epileptogenic foci, because those ASL images were taken after the prolonged and extraordinary activation of neurons in the affected area. During the recovery phase, the differences reduced and the average regional CBF measurement was 54.6 ± 6.1 ml/100 g per minute, which was a little less than the number of previous ASL studies. ASL perfusion MRI imaging provides a method for evaluating regional CBF by using magnetically labeled arterial blood water as an endogenous tracer. With this technique, we can repeatedly evaluate both the brain structure and the level of perfusion at the same time. ASL is noninvasive and easily accessible, and therefore it could become a routine tool for assessment of perfusion in daily practice of pediatric neurology. PMID:27349086

  1. Skin perfusion pressure on the legs measured as the external pressure required for skin reddening after blanching

    DEFF Research Database (Denmark)

    Holstein, P; Nielsen, P.E.; Lund, P; Gyntelberg, F; Poulsen, H L

    1980-01-01

    The skin perfusion on the calf was measured photo-electrically and by isotope washout technique using external counter pressure by a blood pressure cuff. By the photocell the skin blanching threshold external pressure (BTEP) was recorded on histamine flared red skin. By isotope washout technique...... the skin blood flow cessation external pressure (FCEP) was recorded using intra-dermal [131I-]-antipyrine mixed with histamine in estimating the skin blood flow. The external pressure was measured with an airfilled plastic cushion connected to a mercury manometer. Over a wide range of pressures as......Hg (range 18-187) compared to 80.8 mmHg (range 18-158) (P > 0.1). A normal material was obtained from twenty-four subjects measured on the thigh, calf and ankle; the average gradients between the auscultatory brachial mean blood pressure and the BTEP were: thigh 10.7 mmHg (SD 12.7); calf 4.0 mmHg (SD 12...

  2. Effects of renal pelvic high-pressure perfusion on nephrons in a porcine pyonephrosis model.

    Science.gov (United States)

    Wang, Jian; Zhou, DA-Qing; He, Meng; Li, Wen-Gang; Pang, Xiang; Yu, Xiao-Xiang; Jiang, Bo

    2013-05-01

    The aim of this study was to investigate the effects of various renal pelvic pressure gradients on nephrons with purulent infection. Five miniature test pigs were selected. One side of the kidney was used to prepare the pyonephrosis model and the other side was used as the healthy control. A piezometer and a water fill tube were inserted into the renal pelvis through the ureter. Prior to perfusion, punctures were made on the healthy and purulent sides of the kidneys to obtain tissues (as controls). Subsequently, a puncture biopsy was conducted on the kidneys at five pressure levels: 10, 20, 30, 40 and 50 mmHg. Once the renal pelvic pressure had increased, the healthy and injured kidneys presented pathological changes, including dilation of the renal tubule and capsule and compression of the renal glomerulus. When the renal pelvic pressure exceeded 20 mmHg, the injured kidney presented more damage. Electron microscopy revealed that the increase in pressure resulted in the following: the podocyte gap widened, the epithelial cells of the renal capsule separated from the basement membrane, the basement membrane thickness became uneven, the continuity of the basement membrane was interrupted at multiple positions and the renal tubule microvillus arrangement became disorganised. The manifestations in the pyonephrosis model were more distinct compared with those in the healthy kidney. As the renal pelvic pressure exceeds 20 mmHg under a renal purulent infection status, the nephrons become damaged. The extent of the damage is aggravated as the pressure is increased. PMID:23737886

  3. Assessment of cerebral perfusion in chronic tobacco users through spect (single photon emission computed tomography) using Tc-99m HMPAO(metastable technetium-99 labelled hexa-methyl propylene amine oxime)

    International Nuclear Information System (INIS)

    Objective: To determine an association between chronic tobacco use and changes in cerebral perfusion through semi-quantitative scintigraphic assessment employing metastable Technetium-99 labelled hexa-methyl propylene amine oxime single photon emission computed tomography (Tc-99m HMPAO SPECT). Design: Case-control study. Place and duration of study: The study was conducted at the Department of Medical Sciences, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Nilore, Islamabad, from Oct 2001 to May 2002. Patients and Methods: Regional cerebral perfusion in 48 chronic tobacco users was evaluated, utilising a normal database created by HMPAO brain scans of 20 non-tobacco users. Subjects were classified into chronic tobacco users and non-tobacco users through the use of the smoking index (SI). [Smoking Index = Number of years of tobacco use x Number of cigarettes smoked per day]. SI value of 100 was taken as the cut-off value. Regions of interest (ROIs) were declared hypo perfused or hyper perfused if their percentage perfusion values relative to the average perfusion per pixel of the whole slice under evaluation did not fall within + 2 standard deviation (SD) of the mean regional perfusion in the corresponding ROI, in the normal control group. Result: Chronic tobacco users showed 164 hypo perfused ROIs (6.57%) and 138 hyper perfused ROIs (5.53%) out of 2496 ROIs assessed, whereas the normal controls showed only 15 hypo perfused (1.44%) and 27 hyper perfused (2.60%) ROIs out of 1040 ROIs assessed (P < 0.001). Conclusion: Cerebral perfusion in chronic tobacco users was found to be significantly decreased compared to the non-tobacco users. (author)

  4. Assessment of regional cerebral perfusion by 99Tcm-HMPAO SPECT in chronic fatigue syndrome

    International Nuclear Information System (INIS)

    Chronic fatigue syndrome (CFS) is a severely disabling illness of uncertain aetiology. It is characterized by a chronic, sustained or fluctuating sense of debilitating fatigue without any other known underlying medical condition. It is also associated with both somatic and neuropsychological symptoms. Both physical and laboratory findings are usually unremarkable. Regional cerebral blood flow (rCBF) was assessed in 60 clinically defined CFS patients and 14 normal control (NC) subjects using 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) single photon emission computed tomography (SPECT). Compared with the NC group, the CFS group showed significantly lower cortical/cerebellar rCBF ratios, throughout multiple brain regions (P 99Tcm-HMPAO brain SPECT provided objective evidence for functional impairment of the brain in the majority of the CFS subjects. The findings may not be diagnostic of CFS but 99Tcm-HMPAO SPECT may play an important role in clarifying the pathoaetiology of CFS. (Author)

  5. Cerebral Perfusion Measurements in Elderly with Hypertension Using Arterial Spin Labeling

    DEFF Research Database (Denmark)

    Mutsaerts, H J M M; van Dalen, J W; Heijtel, D F R;

    2015-01-01

    PURPOSE: The current study assesses the feasibility and value of crushed cerebral blood flow (CBFcrushed) and arterial transit time (ATT) estimations for large clinical imaging studies in elderly with hypertension. MATERIAL AND METHODS: Two pseudo-continuous arterial spin labeling (ASL) scans with...... (CBFcrushed) and without flow crushers (CBFnon-crushed) were performed in 186 elderly with hypertension, from which CBF and ATT maps were calculated. Standard flow territory maps were subdivided into proximal, intermediate and distal flow territories, based on the measured ATT. The coefficient of variation...... group analyses in elderly with hypertension. The obtained flow territories provide knowledge on vascular anatomy of elderly with hypertension and can be used in future studies to investigate regional vascular effects....

  6. Cerebral perfusion differences in women currently with and recovered from anorexia nervosa.

    Science.gov (United States)

    Sheng, Min; Lu, Hanzhang; Liu, Peiying; Thomas, Binu P; McAdams, Carrie J

    2015-05-30

    Anorexia nervosa is a serious psychiatric disorder characterized by restricted eating, a pursuit of thinness, and altered perceptions of body shape and size. Neuroimaging in anorexia nervosa has revealed morphological and functional alterations in the brain. A better understanding of physiological changes in anorexia nervosa could provide a brain-specific health marker relevant to treatment and outcomes. In this study, we applied several advanced magnetic resonance imaging (MRI) techniques to quantify regional and global cerebral blood flow (CBF) in 25 healthy women (HC), 23 patients currently with anorexia (AN-C) and 19 patients in long-term weight recovery following anorexia (AN-WR). Specifically, CBF was measured with pseudo-continuous arterial spin labeling (pCASL) MRI and then verified by a different technique, phase contrast (PC) MRI. Venous T2 values were determined by T2 relaxation under spin tagging (TRUST) MRI, and were used to corroborate the CBF results. These novel techniques were implemented on a standard 3T MRI scanner without any exogenous tracers, and the total scan duration was less than 10min. Voxel-wise comparison revealed that the AN-WR group showed lower CBF in bilateral temporal and frontal lobes than the AN-C group. Compared with the HC group, the AN-C group also showed higher CBF in the right temporal lobe. Whole-brain-averaged CBF was significantly decreased in the AN-WR group compared with the AN-C group, consistent with the PC-MRI results. Venous T2 values were lower in the AN-WR group than in the AN-C group, consistent with the CBF results. A review of prior work examining CBF in anorexia nervosa is included in the discussion. This study identifies several differences in the cerebral physiological alterations in anorexia nervosa, and finds specific differences relevant to the current state of the disorder. PMID:25795596

  7. Effect of age on exercise-induced alterations in cognitive executive function: relationship to cerebral perfusion.

    Science.gov (United States)

    Lucas, Samuel J E; Ainslie, Philip N; Murrell, Carissa J; Thomas, Kate N; Franz, Elizabeth A; Cotter, James D

    2012-08-01

    Regular exercise improves the age-related decline in cerebral blood flow (CBF) and is associated with improved cognitive function; however, less is known about the direct relationship between CBF and cognitive function. We examined the influence of healthy aging on the capability of acute exercise to improve cognition, and whether exercise-induced improvements in cognition are related to CBF and cortical hemodynamics. Middle cerebral artery blood flow velocity (MCAv; Doppler) and cortical hemodynamics (NIRS) were measured in 13 young (24±5 y) and 9 older (62±3 y) participants at rest and during cycling at 30% and 70% of heart rate range (HRR). Cognitive performance was assessed using a computer-adapted Stroop task (i.e., test of executive function cognition) at rest and during exercise. Average response times on the Stroop task were slower for the older compared to younger group for both simple and difficult tasks (Pexercise (Pexercise (P=0.04 vs. 30% HRR). Higher MCAv was correlated with faster response times for simple and difficult tasks at rest (R(2)=0.47 and R(2)=0.47, respectively), but this relation uncoupled progressively during exercise. Exercise-induced increases in MCAv were similar and unaltered during cognitive tasks for both age groups. In contrast, prefrontal cortical hemodynamic NIRS measures [oxyhemoglobin (O(2)Hb) and total hemoglobin (tHb)] were differentially affected by exercise intensity, age and cognitive task; e.g., there were smaller increases in [O(2)Hb] and [tHb] in the older group between exercise intensities (Pexercising; 2) while MCAv is strongly related to cognition at rest, this relation becomes uncoupled during exercise, and 3) there is dissociation between global CBF and regional cortical oxygenation and NIRS blood volume markers during exercise and engagement of prefrontal cognition. PMID:22230488

  8. Evaluation of normal and pathologic ureteral dynamics: comparison of a radioisotopic method with ureteral pressure/flow perfusion study

    International Nuclear Information System (INIS)

    The ureteral pressure/flow perfusion study has lately been repopularized and its use demonstrated in many forms of suspected obstructive uropathy. The present study was undertaken to compare the ureteral pressure/flow perfusion study with a radioisotopic method of investigating ureteral obstruction. The 2 methods were evaluated with a mongrel canine laboratory model. Both diagnostic modalities were employed concomitantly on intact renoureteral units; first with the ureter unobstructed, then after submission to varying degrees of ureteral occlusion. Analysis of data from these studies shows that the curve pattern produced by the computer generated 99mTc-DTPA renogram is as accurate as ureteral pressure/flow perfusion study in determining the presence and degree of ureteral obstruction

  9. Evaluation of normal and pathologic ureteral dynamics: comparison of a radioisotopic method with ureteral pressure/flow perfusion study

    Energy Technology Data Exchange (ETDEWEB)

    Braren, V.; Bauriedel, J.K.; Jones, W.B.; Goddard, J.

    1982-05-01

    The ureteral pressure/flow perfusion study has lately been repopularized and its use demonstrated in many forms of suspected obstructive uropathy. The present study was undertaken to compare the ureteral pressure/flow perfusion study with a radioisotopic method of investigating ureteral obstruction. The 2 methods were evaluated with a mongrel canine laboratory model. Both diagnostic modalities were employed concomitantly on intact renoureteral units; first with the ureter unobstructed, then after submission to varying degrees of ureteral occlusion. Analysis of data from these studies shows that the curve pattern produced by the computer generated 99mTc-DTPA renogram is as accurate as ureteral pressure/flow perfusion study in determining the presence and degree of ureteral obstruction.

  10. Relationship between systemic hypertension, perfusion pressure and glaucoma: A comparative study in an adult Indian population

    Directory of Open Access Journals (Sweden)

    Amit K Deb

    2014-01-01

    Full Text Available Aims: To study the relationship between blood pressure (BP, intraocular pressure (IOP, mean ocular perfusion pressure (MOPP and primary open angle glaucoma (POAG in patients with hypertension and compare it to a control group of normotensives. Design: Cross-sectional observational study. Materials and Methods: A total of 108 subjects with primary hypertension and 100 age-matched controls without hypertension were enrolled for the study. IOP measurement using Noncontact Tonometer and dilated fundus evaluation using + 90 D lens were done for all cases. Single recording of BP was taken. Gonioscopy, Humphrey′s central visual fields, optical coherence tomography and pachymetry were done for all subjects with IOP > 21 mm Hg or C: D ratio ≥ 0.5 or asymmetry of > 0.2. Statistical Analysis: Univariate and multivariate multinomial regression models were used to determine the association between covariates and risk of glaucoma or glaucoma suspect. Results: There was no difference in the glaucoma status between subjects with and without hypertension. Subjects on antihypertensive medications were 1΍ times more likely to have suspicious glaucoma (odds ratio [OR] =1.56] and nearly twice as likely to have POAG (OR = 1.85. In addition, we found a 31% and 12% reduction in risk of having POAG (95% confidence interval [CI] =13-45%, P = 0.001 and glaucoma suspect (95% CI = 2-21%, P = 0.03 respectively with every 1 mm Hg increment in MOPP. Conclusion: Subjects on antihypertensive medications are more likely to have either glaucoma or glaucoma suspect, and higher ocular perfusion pressure offers relative protection from glaucomatous damage.

  11. In depth pharmacological characterization of endothelin B receptors in the rat middle cerebral artery

    DEFF Research Database (Denmark)

    Szok, D; Hansen-Schwartz, J; Edvinsson, L

    2001-01-01

    middle cerebral artery were cannulated with micropipettes, pressurized and luminally perfused. Vessel diameters were evaluated using a microscope equipped with an imaging system. Both intra- and extraluminal applications of endothelin-1 produced constriction. Intraluminal administration of a selective...

  12. Study of cerebral perfusion in focal epilepsy using SPECT with 99Tcm

    International Nuclear Information System (INIS)

    Locating the epileptogenic focus in patients with drug resistant temporal lobe epilepsy is essential for pre-surgical evaluation of such cases. This is not always possible with a surface electroencephalogram (EEG) and, for that reason, various diagnostic methods have been used employing morphological and functional images. Of these, the ones which can be best related to the EEG images are interictal positron emission tomography (PET) and ictal single photon emission computed tomography (SPECT). Various studies performed with 99Tcm-HMPAO (hexamethypropylene amine oxime) show that the sensitivity of the technique for the location of epileptogenic foci varies between 50 and 70% in the interictal period, but rises to 65-97% if the study is ictal. Recently, the use of 99Tcm-ECD (ethyl cysteinate dimer) in such patients has been described and a high level of agreement was found with both clinical and EEG results. The aim was to evaluate the interictal use of 99Tcm-ECD in ten patients with partial complex epilepsy where there was no evidence of a structural lesion and compare it with extended computerized video EEG in eight of these patients and with standard EEG in two. In one patient, the SPECT was normal, whereas there was a temporal focus in the EEG. In the nine remaining patients, all the epileptogenic foci showed up as hyporperfused zones in the SPECT. The latter also revealed two zones of hypoperfusion which were not apparent in the EEG. Ictal and interictal SPECT were performed on two patients. Here the epileptogenic foci showed up as hyperfused areas in the ictal SPECT and areas with diminished or normal perfusion in the interictal SPECT. It is concluded that SPECT with 99Tcm-ECD is useful for the pre-surgical evaluation of patients with temporal lobe epilepsy. (author). 17 refs, 2 tabs

  13. The evolution of the cerebral blood volume abnormality in patients with ischemic stroke: a CT perfusion study

    Energy Technology Data Exchange (ETDEWEB)

    D' Esterre, Christopher D.; Lee, Ting Yim (Lawson Health Research Inst., London (Canada); Robarts Research Inst., London (Canada)), email: tlee@robarts.ca; Aviv, Richard I. (Sunnybrook Health Sciences Centre, Toronto (Canada))

    2012-05-15

    Background: Accurate identification of the acute infarct core abnormality is important for guiding acute stroke treatment. Abnormality volumes from diffusion-weighted MRI (DWI) and CT perfusion (CTP)-cerebral blood volume (CBV) are highly correlated. DWI lesions have been shown to be reversible at 24 h. Purpose: To examine the temporal profile of the CT perfusion (CTP)-derived CBV abnormality out to 7 days post ischemic stroke. Material and Methods: Twenty-six patients were included. Group A (n = 13) underwent a noncontrast CT (NCCT), CTP/CT angiography (CTA) within 6 h of stroke onset, CTP/CTA at 24 h, and CTP/NCCT at 5-7 days post stroke. Group B (n = 13) underwent a NCCT, CTP/CTA within 6 h of stroke onset, and NCCT at 5-7 days. Recanalization status was established in all patients. For both groups, infarct volumes were traced on 5-7 day NCCT images and superimposed onto all CTP-CBV functional maps to determine CBV. Group B (n = 13) admission images were used to define CBV infarct thresholds for gray and white matter. CBV-lesion overestimation was determined for Group A using the thresholds from Group B. Results: CBV (ml x 100g- 1; mean +- stdev) for gray/white matter, within confirmed infarcted regions (CBVI) at admission, 24 h, and 5-7 days were 1.82 +- 0.56, 1.56 +- 0.42, 1.75 +- 0.31, and 1.38 +- 0.65, 1.13 +- 0.31, 1.32 +- 0.44, respectively, when averaged over all patients (P > 0.05). Four patients had tissue time-density curves from ischemic lesions (TDCi) with an incomplete contrast medium wash-out phase (truncation) at admission and/or 24 h. Compared to admission, gray matter CBVI was higher at 5-7 days for patients with TDCi truncation (P < 0.05). There were no significant CBVI increases for the eight patients without truncation (P > 0.05). Over-estimation of acute CBV lesion was present in 3/4 (75%) and 1/9 (11%) of patients with/without TDCi truncation, respectively. Conclusion: CTP-derived CBV lesion reversal is associated with TDCi truncation

  14. Quantitative cerebral H215O perfusion PET without arterial blood sampling, a method based on washout rate

    International Nuclear Information System (INIS)

    The quantitative determination of regional cerebral blood flow (rCBF) is important in certain clinical and research applications. The disadvantage of most quantitative methods using H215O positron emission tomography (PET) is the need for arterial blood sampling. In this study a new non-invasive method for rCBF quantification was evaluated. The method is based on the washout rate of H215O following intravenous injection. All results were obtained with Alpert's method, which yields maps of the washin parameter K1 (rCBFK1) and the washout parameter k2 (rCBFk2). Maps of rCBFK1 were computed with measured arterial input curves. Maps of rCBFk2* were calculated with a standard input curve which was the mean of eight individual input curves. The mean of grey matter rCBFk2* (CBFk2*) was then compared with the mean of rCBFK1 (CBFK1) in ten healthy volunteer smokers who underwent two PET sessions on day 1 and day 3. Each session consisted of three serial H215O scans. Reproducibility was analysed using the rCBF difference scan 3-scan 2 in each session. The perfusion reserve (PR = rCBFacetazolamide-rCBFbaseline) following acetazolamide challenge was calculated with rCBFk2* (PRk2*) and rCBFK1 (PRK1) in ten patients with cerebrovascular disease. The difference CBFk2*-CBFK1 was 5.90±8.12 ml/min/100 ml (mean±SD, n=55). The SD of the scan 3-scan 1 difference was 6.1% for rCBFk2* and rCBFK1, demonstrating a high reproducibility. Perfusion reserve values determined with rCBFK1 and rCBFk2* were in high agreement (difference PRk2*-PRK1=-6.5±10.4%, PR expressed in percentage increase from baseline). In conclusion, a new non-invasive method for the quantitative determination of rCBF is presented. The method is in good agreement with Alpert's original method and the reproducibility is high. It does not require arterial blood sampling, yields quantitative voxel-by-voxel maps of rCBF, and is computationally efficient and easy to implement. (orig.)

  15. Cerebral perfusion in the predementia stages of Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Binnewijzend, Maja A.A.; Wattjes, Mike P.; Berckel, Bart N.M. van; Barkhof, Frederik [VU University Medical Center, Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, Alzheimercenter Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Benedictus, Marije R.; Prins, Niels D.; Scheltens, Philip [VU University Medical Center, Department of Neurology, Neuroscience Campus Amsterdam, Alzheimer Center Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Center, Department of Physics and Medical Technology, Neuroscience Campus Amsterdam, Alzheimer Center Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der [VU University Medical Center, Department of Neurology, Neuroscience Campus Amsterdam, Alzheimer Center Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); VU University Medical Center, Department of Epidemiology and Biostatistics Neuroscience Campus Amsterdam, Alzheimer Center Amsterdam, P.O. Box 7057, Amsterdam (Netherlands); Teunissen, Charlotte E. [VU University Medical Center, Department of Clinical Chemistry, Neuroscience Campus Amsterdam, Alzheimer Center Amsterdam, P.O. Box 7057, Amsterdam (Netherlands)

    2016-02-15

    To investigate arterial spin-labelling (ASL) cerebral blood flow (CBF) changes in predementia stages of Alzheimer's disease (AD). Data were obtained from 177 patients with subjective complaints, mild cognitive impairment and AD from the Amsterdam Dementia Cohort. AD stages were based on diagnosis and cerebrospinal fluid biomarkers amyloid-β (Aβ) and total-tau (tau). General-linear-models were used to assess relationships between AD stages and total and regional CBF, correcting for age and sex. Decreasing CBF was related to more advanced AD stages in all supratentorial regions (p for trend < 0.05). Post-hoc testing revealed that CBF was lower in AD compared to controls and stage-1 predementia patients (i.e. abnormal Aβ and normal tau) in temporal and parietal regions, and compared to stage-2 predementia patients (i.e. abnormal Aβ and tau) in temporal regions. CBF values of stage-2 predementia patients were numerically in between those of stage-1 predementia patients and AD. The continuing decrease of CBF along the continuum of AD indicates the potential of ASL-CBF as a measure for disease progression. (orig.)

  16. Cerebral perfusion in the predementia stages of Alzheimer's disease

    International Nuclear Information System (INIS)

    To investigate arterial spin-labelling (ASL) cerebral blood flow (CBF) changes in predementia stages of Alzheimer's disease (AD). Data were obtained from 177 patients with subjective complaints, mild cognitive impairment and AD from the Amsterdam Dementia Cohort. AD stages were based on diagnosis and cerebrospinal fluid biomarkers amyloid-β (Aβ) and total-tau (tau). General-linear-models were used to assess relationships between AD stages and total and regional CBF, correcting for age and sex. Decreasing CBF was related to more advanced AD stages in all supratentorial regions (p for trend < 0.05). Post-hoc testing revealed that CBF was lower in AD compared to controls and stage-1 predementia patients (i.e. abnormal Aβ and normal tau) in temporal and parietal regions, and compared to stage-2 predementia patients (i.e. abnormal Aβ and tau) in temporal regions. CBF values of stage-2 predementia patients were numerically in between those of stage-1 predementia patients and AD. The continuing decrease of CBF along the continuum of AD indicates the potential of ASL-CBF as a measure for disease progression. (orig.)

  17. Cerebral perfusion (HMPAO-SPECT) in patients with depression with cognitive impairment versus those with mild cognitive impairment and dementia of Alzheimer's type: a semiquantitative and automated evaluation

    International Nuclear Information System (INIS)

    Comparative evaluation of regional brain perfusion measured by HMPAO-SPECT of patients with mild cognitive impairment (MCI), dementia of Alzheimer's type (DAT) and depression with cognitive impairment (DCI). A total of 736 patients were investigated because of suspected cognitive dysfunction. After exclusion of patients with other forms of dementia than DAT or relevant accompanying disorders, SPECT data from 149 MCI, 131 DAT and 127 DCI patients, and 123 controls without any cognitive impairment, were analysed. Relative cerebral blood flow of 34 anatomical regions was assessed with automated analysis software (BRASS). Calculation of global forebrain perfusion discriminated demented from nondemented patients. Compared to controls DCI patients showed hypoperfusion of the thalamus, lentiform nucleus and medial temporal cortex. MCI patients differed significantly from controls concerning perfusion in both hemispheric temporal and parietal areas, and in the (right hemispheric) posterior part of the cingulate gyrus. MCI and DCI patients differed in the parietal, temporal superior and right hemispheric cingulate gyrus posterior cortices. Global forebrain and regional perfusion was more extensively reduced in DAT patients and discriminated them from controls, and MCI and DCI patients. Frontal perfusion disturbance was only present in DAT patients. Automated analysis of HMPAO-SPECT data from MCI patients showed significant perfusion deficits in regions also involved in DAT patients, but ROC analysis demonstrated only moderate sensitivity and specificity for differentiating DAT patients from controls and DCI patients. Frontal hypoperfusion seems to correspond with conversion from MCI to DAT. Finally, the results in DCI patients again raise the question of depression as an early symptom of neurodegeneration. (orig.)

  18. Cardiopulmonary fitness correlates with regional cerebral grey matter perfusion and density in men with coronary artery disease.

    Directory of Open Access Journals (Sweden)

    Bradley J MacIntosh

    Full Text Available PURPOSE: Physical activity is associated with positive effects on the brain but there is a paucity of clinical neuroimaging data in patients with coronary artery disease (CAD, a cardiovascular condition associated with grey matter loss. The purpose of this study was to determine which brain regions are impacted by cardiopulmonary fitness and with the change in fitness after 6 months of exercise-based cardiac rehabilitation. METHODS: CAD patients underwent magnetic resonance imaging at baseline, and peak volume of oxygen uptake during exercise testing (VO2Peak was measured at baseline and after 6 months of training. T1-weighted structural images were used to perform grey matter (GM voxel-based morphometry (VBM. Pseudo-continuous arterial spin labeling (pcASL was used to produce cerebral blood flow (CBF images. VBM and CBF data were tested voxel-wise using VO2Peak and age as explanatory variables. RESULTS: In 30 men with CAD (mean age 65±7 years, VBM and CBF identified 7 and 5 respective regions positively associated with baseline VO2Peak. These included the pre- and post-central, paracingulate, caudate, hippocampal regions and converging findings in the putamen. VO2Peak increased by 20% at follow-up in 29 patients (t = 9.6, df = 28, p<0.0001. Baseline CBF in the left post-central gyrus and baseline GM density in the right putamen predicted greater change in VO2Peak. CONCLUSION: Perfusion and GM density were associated with fitness at baseline and with greater fitness gains with exercise. This study identifies new neurobiological correlates of fitness and demonstrates the utility of multi-modal MRI to evaluate the effects of exercise in CAD patients.

  19. Cerebral perfusion and glucose metabolism in Alzheimer's disease and frontotemporal dementia: two sides of the same coin?

    International Nuclear Information System (INIS)

    Alzheimer's disease (AD) and frontotemporal (FTD) dementia can be differentiated using [18F]-2-deoxy-2-fluoro-D-glucose (FDG)-PET. Since cerebral blood flow (CBF) is related to glucose metabolism, our aim was to investigate the extent of overlap of abnormalities between AD and FTD. Normalized FDG-PET and arterial spin labelling (ASL-MRI)-derived CBF was measured in 18 AD patients (age, 64 ± 8), 12 FTD patients (age, 61 ± 8), and 10 controls (age, 56 ± 10). Voxel-wise comparisons, region-of-interest (ROI), correlation, and ROC curve analyses were performed. Voxel-wise comparisons showed decreased CBF and FDG uptake in AD compared with controls and FTD in both precuneus and inferior parietal lobule (IPL). Compared with controls and AD, FTD patients showed both hypometabolism and hypoperfusion in medial prefrontal cortex (mPFC). ASL and FDG were related in precuneus (r = 0.62, p < 0.001), IPL (r = 0.61, p < 0.001), and mPFC across groups (r = 0.74, p < 001). ROC analyses indicated comparable performance of perfusion and metabolism in the precuneus (AUC, 0.72 and 0.74), IPL (0.85 and 0.94) for AD relative to FTD, and in the mPFC in FTD relative to AD (both 0.68). Similar patterns of hypoperfusion and hypometabolism were observed in regions typically associated with AD and FTD, suggesting that ASL-MRI provides information comparable to FDG-PET. (orig.)

  20. Cerebral perfusion and glucose metabolism in Alzheimer's disease and frontotemporal dementia: two sides of the same coin?

    Energy Technology Data Exchange (ETDEWEB)

    Verfaillie, Sander C.J.; Adriaanse, Sofie M.; Binnewijzend, Maja A.A.; Benedictus, Marije R.; Ossenkoppele, Rik [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); VU University Medical Centre, Alzheimer Centre and Department of Neurology, P.O. Box 7057, Amsterdam (Netherlands); Wattjes, Mike P.; Lammertsma, Adriaan A.; Boellaard, Ronald; Berckel, Bart N.M. van; Barkhof, Frederik [VU University Medical Centre, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Pijnenburg, Yolande A.L.; Scheltens, Philip [VU University Medical Centre, Alzheimer Centre and Department of Neurology, P.O. Box 7057, Amsterdam (Netherlands); Flier, Wiesje M. van der [VU University Medical Centre, Alzheimer Centre and Department of Neurology, P.O. Box 7057, Amsterdam (Netherlands); VU University Medical Centre, Department of Epidemiology and Biostatistics, Amsterdam (Netherlands); Kuijer, Joost P.A. [VU University Medical Centre, Department of Physics and Medical Technology, Amsterdam (Netherlands)

    2015-10-15

    Alzheimer's disease (AD) and frontotemporal (FTD) dementia can be differentiated using [{sup 18}F]-2-deoxy-2-fluoro-D-glucose (FDG)-PET. Since cerebral blood flow (CBF) is related to glucose metabolism, our aim was to investigate the extent of overlap of abnormalities between AD and FTD. Normalized FDG-PET and arterial spin labelling (ASL-MRI)-derived CBF was measured in 18 AD patients (age, 64 ± 8), 12 FTD patients (age, 61 ± 8), and 10 controls (age, 56 ± 10). Voxel-wise comparisons, region-of-interest (ROI), correlation, and ROC curve analyses were performed. Voxel-wise comparisons showed decreased CBF and FDG uptake in AD compared with controls and FTD in both precuneus and inferior parietal lobule (IPL). Compared with controls and AD, FTD patients showed both hypometabolism and hypoperfusion in medial prefrontal cortex (mPFC). ASL and FDG were related in precuneus (r = 0.62, p < 0.001), IPL (r = 0.61, p < 0.001), and mPFC across groups (r = 0.74, p < 001). ROC analyses indicated comparable performance of perfusion and metabolism in the precuneus (AUC, 0.72 and 0.74), IPL (0.85 and 0.94) for AD relative to FTD, and in the mPFC in FTD relative to AD (both 0.68). Similar patterns of hypoperfusion and hypometabolism were observed in regions typically associated with AD and FTD, suggesting that ASL-MRI provides information comparable to FDG-PET. (orig.)

  1. Development and application of an automated analysis method for individual cerebral perfusion single photon emission tomography images

    International Nuclear Information System (INIS)

    Neurological images may be analysed by performing voxel by voxel comparisons with a group of control subject images. An automated, 3D, voxel-based method has been developed for the analysis of individual single photon emission tomography (SPET) scans. Clusters of voxels are identified that represent regions of abnormal radiopharmaceutical uptake. Morphological operators are applied to reduce noise in the clusters, then quantitative estimates of the size and degree of the radiopharmaceutical uptake abnormalities are derived. Statistical inference has been performed using a Monte Carlo method that has not previously been applied to SPET scans, or for the analysis of individual images. This has been validated for group comparisons of SPET scans and for the analysis of an individual image using comparison with a group. Accurate statistical inference was obtained independent of experimental factors such as degrees of freedom, image smoothing and voxel significance level threshold. The analysis method has been evaluated for application to cerebral perfusion SPET imaging in ischaemic stroke. It has been shown that useful quantitative estimates, high sensitivity and high specificity may be obtained. Sensitivity and the accuracy of signal quantification were found to be dependent on the operator defined analysis parameters. Recommendations for the values of these parameters have been made. The analysis method developed has been compared with an established method and shown to result in higher specificity for the data and analysis parameter sets tested. In addition, application to a group of ischaemic stroke patient SPET scans has demonstrated its clinical utility. The influence of imaging conditions has been assessed using phantom data acquired with different gamma camera SPET acquisition parameters. A lower limit of five million counts and standardisation of all acquisition parameters has been recommended for the analysis of individual SPET scans. (author)

  2. Effects of regional cerebral blood flow perfusion on learning and memory function and its molecular mechanism in rats

    Institute of Scientific and Technical Information of China (English)

    Cunli Xu; Wenhua Wu; Lingbin Kong

    2016-01-01

    Objective:To study the effects of regional cerebral blood flow (rCBF) perfusion on learning and memory function in special brain areas and its molecular mechanism in rat. Methods: Sixty-four adult male healthy Sprague-Dawley (SD) rats were randomly divided into two groups: Afalse operation group and an operation group. The false operation group was randomly divided into four subgroups (A0, B0, C0, and D0) and the operation group was randomly divided into four subgroups (A, B, C, and D), with eight rats in each subgroup. The operation group underwent bilateral common carotid artery permanent ligation, while the other group only underwent a skin incision without the bilateral common carotid artery permanent ligation. Learning memory function of rats in each subgroup was measured using a Y-maze at 4 h, 8 h, 24 h, and 3 days after surgery. The rCBF in the right frontal lobe and hippocampus was detected using the Periflux PF model laser Doppler flowmetry and c-fos, c-jun, Bcl-2, and Bax protein expression in the right frontal lobe and hippocampus was measured using immunohistochemistry. Results: The rCBF in the right frontal lobule division and right hippocampus division was significantly lower in the operation group than in the false operation group (P Conclusions:rCBF decrease can impair learning and memory function in rats, which may be related to the increased expression of c-fos, c-jun, Bcl-2, and Bax proteins in the frontal cortex and hippocampus.

  3. Cerebral perfusion SPECT using Tc-99m-d,l-HMPAO. Comparative study with I-123 IMP and CBF measured by PET

    Energy Technology Data Exchange (ETDEWEB)

    Nishizawa, Sadahiko; Yonekura, Yoshiharu; Fujita, Tohru; Senda, Michio; Konishi, Junji; Ishikawa, Masatsune; Fukuyama, Hidenao

    1987-10-01

    To evaluate clinical usefulness of technetium-99m-d,l-hexamethylpropyleneamine oxime (HMPAO) as cerebral perfusion agent for SPECT, we compared the distribution of HMPAO with that of N-isopropyl-(I-123)p-iodoamphetamine (IMP) and regional cerebral blood flow (rCBF) measured by PET. In HMPAO study, we performed serial SPECT scans until 5 hr in 7 cases, and single SPECT scan at 5 min after the injection in the other 17 cases. Among 24 cases, IMP-SPECT was performed in 9 cases and PET was done in 17 cases. All SPECT scans were performed with multi-detecter SPECT scanner. The regional distribution of HMPAO in the brain did not show major changes visually except the lesions of meningioma and arteriovenous malformation, and the regional activity showed 1 % increase at 45 min and 4 % decrease at 5 hr compared with the activity at 5 min. In cases with cerebral infarction, major discrepancy was not observed among 3 studies. However, in cases having mild regional hypoperfusion of less than 30 % decrease in rCBF compared with the non-affected area, reduced perfusion was not clearly visualized in the HMPAO-SPECT while IMP-SPECT demonstrated the ischemic lesion with better contrast. Although HMPAO is useful to assess rCBF using SPECT with the advantage of its availability at any time, the present study raised a question about the limitation of the detectability in mild ischemia.

  4. Cerebral Metabolic Profiling of Hypothermic Circulatory Arrest with and Without Antegrade Selective Cerebral Perfusion: Evidence from Nontargeted Tissue Metabolomics in a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Li-Hua Zou

    2016-01-01

    Conclusions: The present study applied metabolomics analysis to identify the cerebral metabolic profiling in rabbits with ASCP, and the results may shed new lights that cerebral metabolism is better preserved by ASCP compared with DHCA alone.

  5. The effect of positive end-expiratory pressure on regional ventilation and perfusion in the normal and injured primate lung.

    Science.gov (United States)

    Hammon, J W; Wolfe, W G; Moran, J F; Jones, R H; Sabiston, D C

    1976-11-01

    Although positive end-expiratory pressure (PEEP) is being employed in the management of respiratory insufficiency, many of its physiological effects remain undetermined. The cardiopulmonary effects of PEEP as well as its effect on regional ventilation and perfusion were studied in 10 baboons before and after pulmonary injury with oleic acid. In the normal lung, there was significant improvement in oxygenation at a PEEP of 5 cm. of water secondary to improved ventilation and perfusion in all PEEP greater than 5 cm. of water produced increasing mismatch of ventilation and perfusion in all zones. After oleic acid was injected, hypoxemia was evident with a reversal of the normal ventilation-perfusion (V/Q) relationship between upper and lower lung zones. This mismatch of ventilation and perfusion was corrected at a PEEP of 15 cm. of water. It was reasonable to conclude that the use of PEEP in the injured lung exerts it beneficial effect by balancing regional ventilation and perfusion in addition to increasing functional residual capacity. PMID:824505

  6. NO mediates downregulation of RBF after a prolonged reduction of renal perfusion pressure in SHR

    DEFF Research Database (Denmark)

    Sørensen, Charlotte Mehlin; Leyssac, Paul Peter; Skott, Ole;

    2003-01-01

    The aim of the study was to investigate mechanisms underlying the downregulation of renal blood flow (RBF) after a prolonged reduction in renal perfusion pressure (RPP) in adult spontaneously hypertensive rats (SHR). We tested the effect on the RBF response of clamping plasma ANG II in sevoflurane......-anesthetized SHR. We also tested the effect of general cyclooxygenase (COX) inhibition and inhibition of the inducible COX-2. Furthermore, we assessed the effect of clamping the nitric oxide (NO) system. A prolonged period (15 min) of reduced RPP induced a downregulation of RBF. This was unchanged after clamping...... of plasma ANG II concentrations, general COX inhibition, and specific inhibition of COX-2. In contrast, clamping the NO system diminished the ability of SHR to downregulate RBF to a lower level. The downregulation of RBF was not associated with a resetting of the lower limit of autoregulation in the...

  7. Estudio sobre las alteraciones de la perfusión cerebral valorado mediante SPECT cerebral, en pacientes usuarios de drogas de abuso Study of brain perfusion anomalies assessed with cerebral SPECT in drug abuse patients

    Directory of Open Access Journals (Sweden)

    Eduardo Rodríguez Raimondo

    2010-06-01

    Full Text Available El abuso de sustancias psicotóxicas representa un gran problema de Salud Pública en los diferentes distritos estatales. Este trabajo pretende determinar cuáles son los efectos nocivos de estas sustancias sobre el parénquima cerebral de los pacientes en los que se ha demostrado un consumo activo de drogas prohibidas. Para ello se empleó la técnica de SPECT cerebral con ECD - 99mTc aplicada a aquellos pacientes adictos, a los cuales previamente se les realizó una encuesta para conocer el tipo de droga, el tiempo y la duración de su adicción. Como resultado se detectó que el mayor número de defectos de perfusión corticales, es decir, déficits funcionales, se localizaron en la corteza órbito-frontal y en los lóbulos temporales, lo cual explicaría los importantes trastornos de conducta y personalidad que manifiestan estos pacientes. Se demostró con este método que el SPECT cerebral es un excelente método para detectar las zonas afectadas por estas drogas psicoadictivas, su extensión y la evolución y posible respuesta al tratamiento.Psychoactive drug abuse is a major public health problem in many districts. This study seeks to determine the harmful effects of such drugs on the brain parenchyma of patients known to abuse illegal drugs. Brain scans were obtained using 99 M Tc- ECD SPECT from drug addicts that had been previously surveyed to ascertain the type of drug, the timing and duration of their addiction SPECT findings showed a larger number of cortical perfusion defects, that is to say functional defects located in the orbital-frontal cortex and in the temporal lobes that may explain the significant behavior and personality disorders these patients display. Cerebral SPECT showed to be an excellent method to detect areas affected by psychoactive drugs, their extent, likely evolution and response to treatment.

  8. Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

    Science.gov (United States)

    Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

    2013-07-01

    Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment. PMID:23623332

  9. Cirurgia do arco aórtico com perfusão cerebral bilateral pelo isolamento do tronco braquiocefálico e da artéria carótida esquerda Aortic arch surgery with bilateral cerebral perfusion by isolation of brachiocephalic trunk and left carotid artery

    Directory of Open Access Journals (Sweden)

    Valdo José Carreira

    2008-03-01

    Full Text Available OBJETIVO: Estudar os resultados da técnica descrita por Carreira et al. com utilização de perfusão cerebral seletiva bilateral (PCSAB pelo isolamento do tronco braquiocefálico e artéria carótida esquerda. MÉTODOS: Quinze pacientes foram operados consecutivamente entre de junho de 2005 e setembro de 2007. Os dados foram analisados por programa informatizado Epi Info e significância estatística com p0,05. CONCLUSÃO: A técnica de PCSAB é reprodutível e apresenta resultados semelhantes aos da literatura mundial. A excelente evolução neurológica e o fácil controle de sangramentos nas linhas de sutura podem ter contribuído com os resultados obtidos.OBJECTIVE: To evaluate the results of a technique described by Carreira et al. using bilateral antegrade selective cerebral perfusion by isolating the brachiocephalic trunk and the left carotid artery. METHODS: Fifteen patients were operated between June 2005 and September 2007. Data analysis were performed using Epi Info and statistical significance was set at p0.05. CONCLUSION: The technique of bilateral selective cerebral perfusion described by Carreira et al. can be performed by others and presents similar results to the international literature. The excellent neurological outcome and easy bleeding control on surgical sutures lines are the major advantages of this new procedure.

  10. The cerebral hemodynamics of normotensive hypovolemia during lower-body negative pressure

    Science.gov (United States)

    Giller, C. A.; Levine, B. D.; Meyer, Y.; Buckey, J. C.; Lane, L. D.; Borchers, D. J.

    1992-01-01

    Although severe hypovolemia can lead to hypotension and neurological decline, many patients with neurosurgical disorders experience a significant hypovolemia while autonomic compensatory mechanisms maintain a normal blood pressure. To assess the effects of normotensive hypovolemia upon cerebral hemodynamics, transcranial Doppler ultrasound monitoring of 13 healthy volunteers was performed during graded lower-body negative pressure of up to -50 mm Hg, an accepted laboratory model for reproducing the physiological effects of hypovolemia. Middle cerebral artery flow velocity declined by 16% +/- 4% (mean +/- standard error of the mean) and the ratio between transcranial Doppler ultrasound pulsatility and systemic pulsatility rose 22% +/- 8%, suggesting cerebral small-vessel vasoconstriction in response to the sympathetic activation unmasked by lower-body negative pressure. This vasoconstriction may interfere with the autoregulatory response to a sudden fall in blood pressure, and may explain the common observation of neurological deficit during hypovolemia even with a normal blood pressure.

  11. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    OpenAIRE

    Bronzwaer, Anne-Sophie G. T.; Stok, Wim J.; Westerhof, Berend E.; Johannes J. van Lieshout

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI a...

  12. Arterial pressure variations as parameters of brain perfusion in response to central blood volume depletion and repletion

    OpenAIRE

    Anne-SophieG.T.Bronzwaer; WimJ.Stok; BerendE.Westerhof; JohannesJ.Van Lieshout

    2014-01-01

    Rationale: A critical reduction in central blood volume (CBV) is often characterized by hemodynamic instability. Restoration of a volume deficit may be established by goal-directed fluid therapy guided by respiration-related variation in systolic- and pulse pressure (SPV and PPV). Stroke volume index (SVI) serves as a surrogate end-point of a fluid challenge but tissue perfusion itself has not been addressed. Objective: To delineate the relationship between arterial pressure variations, SVI ...

  13. Comparison of CT perfusion summary maps to early diffusion-weighted images in suspected acute middle cerebral artery stroke

    International Nuclear Information System (INIS)

    Objectives: To assess the accuracy and reliability of one vendor's (Vital Images, Toshiba Medical, Minnetonka, MN) automated CT perfusion (CTP) summary maps in identification and volume estimation of infarcted tissue in patients with acute middle cerebral artery (MCA) distribution infarcts. Subjects and methods: From 1085 CTP examinations over 5.5 years, 43 diffusion-weighted imaging (DWI)-positive patients were included who underwent both CTP and DWI <12 h after symptom onset, with another 43 age-matched patients as controls (DWI-negative). Automated delay-corrected postprocessing software (DC-SVD) generated both infarct “core only” and “core + penumbra” CTP summary maps. Three reviewers independently tabulated Alberta Stroke Program Early CT scores (ASPECTS) of both CTP summary maps and coregistered DWI. Results: Of 86 included patients, 36 had DWI infarct volumes ≤70 ml, 7 had volumes >70 ml, and 43 were negative; the automated CTP “core only” map correctly classified each as >70 ml or ≤70 ml, while the “core + penumbra” map misclassified 4 as >70 ml. There were strong correlations between DWI volume with both summary map-based volumes: “core only” (r = 0.93), and “core + penumbra” (r = 0.77) (both p < 0.0001). Agreement between ASPECTS scores of infarct core on DWI with summary maps was 0.65–0.74 for “core only” map, and 0.61–0.65 for “core + penumbra” (both p < 0.0001). Using DWI-based ASPECTS scores as the standard, the accuracy of the CTP-based maps were 79.1–86.0% for the “core only” map, and 83.7–88.4% for “core + penumbra.” Conclusion: Automated CTP summary maps appear to be relatively accurate in both the detection of acute MCA distribution infarcts, and the discrimination of volumes using a 70 ml threshold

  14. Surfactant nebulisation prevents the adverse effects of surfactant therapy on blood pressure and cerebral blood flow in rabbits with severe respiratory failure

    NARCIS (Netherlands)

    Dijk, PH; Heikamp, A; Oetomo, SB

    1997-01-01

    Objective: Surfactant replacement therapy for the neonatal respiratory distress syndrome has shown beneficial effects on lung function and survival. Recently, rapid fluctuations of haemodynamics and cerebral perfusion following surfactant instillation have beer, described and an association with the

  15. Combined SPECT imaging of regional cerebral blood flow (99mTc-hexamethyl-propyleneamine oxime, HMPAO) and blood volume (99mTc-RBC) to assess regional cerebral perfusion reserve in patients with cerebrovascular disease

    International Nuclear Information System (INIS)

    In 53 patients with cerebrovascular disease (CDV), regional cerebral blood flow (CBF) and blood volume (CBV) were imaged by SPECT within one session. Slice division (CBF:CBV) yielded distribution of regional cerebral perfusion reserve (CPR). Semiquantitative evaluation was obtained from manually set ROIs by interhemispherical ratios (for CBF, CBV and CPR), using 2 SD from a normal group (n=10) as a threshold. Sensitivity was 59% for CBF, 94% for CBV and 83% for CPR. Combined sensitivity was 98%. Establishing three constellations for CBF, CBV and CPR, regionally normal CBFs but quantitatively increased CBVs (+69%) and decreased CPRs (-31%) were found in relatively early stages of CVD. Very advanced cases showed decreased CBFs (-65%), CBVs (-40%), CPRs (-49%) and a surrounding penumbra. In 87% (46/53 patients), such rheologically postulated constellations could be demonstrated. We conclude that combined CBF and CBV SPECT, assisted by CPR images, is a promising tool to detect CVD and to assess its individual regional severity. (orig.)

  16. Wound healing in below-knee amputations in relation to skin perfusion pressure

    DEFF Research Database (Denmark)

    Holstein, P; Sager, P; Lassen, N A

    1979-01-01

    In 60 below-knee amputations the healing of the stumps was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 131I- or 125I--antipyrine mixed with histamine. Of the eight cases with an SPP below 20 mmHg, no...... less than six (75 per cent) failed to heal and required reamputation at the above-knee level. Of the 12 cases with an SPP between 20 and 30 mmHg four cases (33 per cent) failed to heal but of the 40 cases with an SPP above 30 mmHg, there were only four cases (10 per cent) which did not heal. The...... difference in failure rate is highly significant (P less than 0.01). Four out of 30 diabetic patients required reamputation as against 10 out of 30 non-diabetics (0.05 less than P less than 0.10). The average SPP was higher in the diabetic group: 57 mmHg (range 18-93 mmHg) compared with 34 mmHg (range 8...

  17. Wound healing in above-knee amputations in relation to skin perfusion pressure

    International Nuclear Information System (INIS)

    In 59 above-knee amputations healing of the stumps was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 132I--or 125I--antipyrine mixed with histamine. Out of the 11 cases with an SPP below 30 mmHg no less than nine (82 per cent) suffered severe wound complications. Out of the 48 cases with an SPP above 30 mmHg severe wound complications occurred in only four cases (8 per cent). The difference in wound complication rate is highly significant (P<0.01). The postoperative SPP measured on the stumps was on average only slightly and insignificantly higher than the preoperative values, explaining why the preoperative values related so closely to the postoperative clinical course. We conclude that the SPP can be used to predict ischaemic wound complications in above-knee amputations as has previously been shown to be the case in below-knee amputations. (author)

  18. Volume perfusion CT (VPCT) for the differential diagnosis of patients with suspected cerebral vasospasm: Qualitative and quantitative analysis of 3D parameter maps

    Energy Technology Data Exchange (ETDEWEB)

    Dolatowski, K., E-mail: karoline.dolatowski@gmail.com [Department of Neuroradiology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen (Germany); Malinova, V., E-mail: vesna.malinova@gmail.com [Department of Neurosurgery, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen (Germany); Frölich, A.M.J., E-mail: a.froelich@gmail.com [Department of Neuroradiology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen (Germany); Schramm, R., E-mail: ramona.schramm@med.uni-goettingen.de [Department of Neuroradiology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen (Germany); Haberland, U., E-mail: ulrike.haberland@siemens.com [Siemens AG, Healthcare Sector, Computed Tomography, H IM CR R and D PA SC, Siemensstr. 1, 91301 Forchheim (Germany); Klotz, E., E-mail: ernst.klotz@siemens.com [Siemens AG, Healthcare Sector, Computed Tomography, H IM CR R and D PA SC, Siemensstr. 1, 91301 Forchheim (Germany); Mielke, D., E-mail: dorothee.wachter@med.uni-goettingen.de [Department of Neurosurgery, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen (Germany); Knauth, M., E-mail: michael.knauth@med.uni-goettingen.de [Department of Neuroradiology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075 Göttingen (Germany); Schramm, P., E-mail: Peter.Schramm@uksh.de [Department of Neuroradiology, UKSH University hospital Schleswig-Holstein Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck (Germany)

    2014-10-15

    Object: Cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH) implies high risk for secondary ischemia. It requires early diagnosis to start treatment on time. We aimed to assess the utility of “whole brain” VPCT for detecting localization and characteristics of arterial vasospasm. Methods: 23 patients received a non-enhanced CT, VPCT and CTA of the brain. The distribution of ischemic lesions was analyzed on 3D-perfusion-parameter-maps of CBF, CBV, MTT, TTS, TTP, and TTD. CT-angiographic axial and coronal maximum-intensity-projections were reconstructed to determine arterial vasospasm. CT-data was compared to DSA, if performed additionally. Volume-of-interest placement was used to obtain quantitative mean VPCT values. Results: 82% patients (n = 19) had focal cerebral hypoperfusion. 100% sensitivity and 100% specificity was found for TTS (median 1.9 s), MTT (median 5.9 s) and TTD (median 7.6 s). CBV showed no significant differences. In 78% (n = 18) focal vessel aberrations could be detected either on CTA or DSA or on both. Conclusion: VPCT is a non-invasive method with the ability to detect focal perfusion deficits almost in the whole brain. While DSA remains to be the gold standard for detection of CV, VPCT has the potential to improve noninvasive diagnosis and treatment decisions.

  19. Volume perfusion CT (VPCT) for the differential diagnosis of patients with suspected cerebral vasospasm: Qualitative and quantitative analysis of 3D parameter maps

    International Nuclear Information System (INIS)

    Object: Cerebral vasospasm (CV) following subarachnoid hemorrhage (SAH) implies high risk for secondary ischemia. It requires early diagnosis to start treatment on time. We aimed to assess the utility of “whole brain” VPCT for detecting localization and characteristics of arterial vasospasm. Methods: 23 patients received a non-enhanced CT, VPCT and CTA of the brain. The distribution of ischemic lesions was analyzed on 3D-perfusion-parameter-maps of CBF, CBV, MTT, TTS, TTP, and TTD. CT-angiographic axial and coronal maximum-intensity-projections were reconstructed to determine arterial vasospasm. CT-data was compared to DSA, if performed additionally. Volume-of-interest placement was used to obtain quantitative mean VPCT values. Results: 82% patients (n = 19) had focal cerebral hypoperfusion. 100% sensitivity and 100% specificity was found for TTS (median 1.9 s), MTT (median 5.9 s) and TTD (median 7.6 s). CBV showed no significant differences. In 78% (n = 18) focal vessel aberrations could be detected either on CTA or DSA or on both. Conclusion: VPCT is a non-invasive method with the ability to detect focal perfusion deficits almost in the whole brain. While DSA remains to be the gold standard for detection of CV, VPCT has the potential to improve noninvasive diagnosis and treatment decisions

  20. Epileptic patterns of local cerebral metabolism and perfusion in man determined by emission computed tomography of 18FDG and 13NH3

    International Nuclear Information System (INIS)

    Seventeen patients with partial epilepsy had EEG monitoring concurrent with cerebral emission computed tomography (ECT) after 18F-fluorodeoxyglucose (18FDG) and 13N-ammonia were given intravenously as indicators of local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. In 12 of 15 patients who had unilateral or focal electrical abnormalities, interictal 18FDG scan patterns clearly showed localized regions of decreased (20% to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization. These hypometabolic zones appeared normal on x-ray computed tomography in all but three patients and were unchanged on scans repeated on different days. In 5 of 6 patients who underwent temporal lobectomy, the interictal 18FDG scan correctly detected the pathologically confirmed lesion as a hypometabolic zone, and removal of the lesion site resulted in marked clinical improvement. In contrast, the ictal 18FDG scan patterns clearly showed foci of increased (82% to 130%) LCMR/sub glc/, which correlated temporally and anatomically with ictal EEG spike foci and were within the zones of interictal hypometabolism (3 studies in 2 patients). 13NH3 distributions paralleled 18FDG increases and decreases in abnormal zones, but 13NH3 differences were of lesser magnitude. When the relationship of 13NH3 uptake to local blood flow found in dog brain was applied as a correction to the patients' 13NH3 scan data, local alterations in perfusion and glucose utilization were usually matched, both in the interictal and ictal states

  1. Multiple-input nonlinear modelling of cerebral haemodynamics using spontaneous arterial blood pressure, end-tidal CO2 and heart rate measurements.

    Science.gov (United States)

    Marmarelis, V Z; Mitsis, G D; Shin, D C; Zhang, R

    2016-05-13

    In order to examine the effect of changes in heart rate (HR) upon cerebral perfusion and autoregulation, we include the HR signal recorded from 18 control subjects as a third input in a two-input model of cerebral haemodynamics that has been used previously to quantify the dynamic effects of changes in arterial blood pressure and end-tidal CO2upon cerebral blood flow velocity (CBFV) measured at the middle cerebral arteries via transcranial Doppler ultrasound. It is shown that the inclusion of HR as a third input reduces the output prediction error in a statistically significant manner, which implies that there is a functional connection between HR changes and CBFV. The inclusion of nonlinearities in the model causes further statistically significant reduction of the output prediction error. To achieve this task, we employ the concept of principal dynamic modes (PDMs) that yields dynamic nonlinear models of multi-input systems using relatively short data records. The obtained PDMs suggest model-driven quantitative hypotheses for the role of sympathetic and parasympathetic activity (corresponding to distinct PDMs) in the underlying physiological mechanisms by virtue of their relative contributions to the model output. These relative PDM contributions are subject-specific and, therefore, may be used to assess personalized characteristics for diagnostic purposes. PMID:27044989

  2. Effect of noradrenaline on tail arteries of SHR and WKY under perfusion at constant flow and constant pressure

    DEFF Research Database (Denmark)

    Matchkov, Vladimir; Tarasova, Olga S; Timin, Eugeny N;

    1997-01-01

    pressure. Two series of experiments were performed. In the first series, vessels were perfused/superfused with Krebs-Henseleit solution. In the second one a modified salt solution was used, in which NaCl was totally replaced by an equimolar amount of KCI. Under constant flow conditions noradrenaline evoked......, vasoconstriction at constant pressure in SHR became more pronounced than that in WKY. We suggest that there is greater wall thickness:lumen diameter ratio in SHR vessels and thus different contribution of distension-activated myogenic response is of primary importance for the data obtained....... a more prominent resistance increase in SHR compared with WKY independently of the composition of solution (normal or high-K+) used. At constant pressure perfusion with normal solution, the vasoconstrictor response to noradrenaline was more prominent in WKY. Under application of high-K+ solution...

  3. Angiography and cerebral perfusion scintigraphy in balloon test occlusion of carotid artery in head and neck tumors

    Energy Technology Data Exchange (ETDEWEB)

    Hertel, A. [Klinikum Fulda (Germany). Nuclear Medicine; Goerling, S. [Klinikum Schwerin (Germany). Radiology; Schwager, K. [Klinikum Fulda (Germany). Head and Neck; Hofmann, E. [Klinikum Fulda (Germany). Neuroradiology

    2012-03-15

    Surgery of head and neck tumors and other tumors involving the carotid artery may demand complete sacrifice of the carotid as part of the necessary tumor therapy. Sacrifice of the carotid may result in permanent brain perfusion damage. This uncorrectable procedure has to be tested beforehand in order to exclude this possibility. In order to predict this possible unstable hemodynamic brain perfusion damage, we evaluated 12 patients with head neck tumors prior to possible sacrifice of the carotid. The following tests were applied: angiography of the neck vessels, balloon test occlusion (BTO) of the carotid lasting 10 minutes combined with perfusion reserve testing using 1000 mg acetazolamide i.v. All patients received brain perfusion scintigraphy SPECT with Tc-99m HMPAO injected during BTO. All patient data were evaluated for clinical neurological defects under BTO. Perfusion of the great vessels was evaluated semiquantitatively for angiography (filling delay of the ophthalmic artery) and perfusion SPECT. None of the patients suffered from neurological defects. 9/12 patients showed mild to severe perfusion defects. 9/12 patients showed filling delays of more than 1 second. Both tests showed a very good correlation (p = 0.005). Only 2/12 cases were discrepant in one degree. All severe defects were congruent in both tests. None of the patients with severe defects underwent sacrifice of the carotid. Both tests resulted in increased security regarding the prediction of possible brain perfusion damage. The combination of angiography and brain scintigraphy is logistically easy and has a high value of prediction. (orig.)

  4. Acute retinal ischemia caused by controlled low ocular perfusion pressure in a porcine model. Electrophysiological and histological characterisation

    DEFF Research Database (Denmark)

    Kyhn, Maria Voss; Warfvinge, Karin; Scherfig, Erik;

    2009-01-01

    The purpose of this study was to establish, and characterize a porcine model of acute, controlled retinal ischemia. The controlled retinal ischemia was produced by clamping the ocular perfusion pressure (OPP) in the left eye to 5 mm Hg for 2 h. The OPP was defined as mean arterial blood pressure...... (MAP) minus the intraocular pressure (IOP). It was clamped to 0-30 mm Hg by continuous monitoring of MAP and adjustment of the IOP, which was controlled by cannulation of the anterior chamber. Inner retinal function was assessed by induced multifocal electroretinography (mfERG) with comparisons of the...

  5. Comparing CT perfusion with oxygen partial pressure in a rabbit VX2 soft-tissue tumor model

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the oxygen partial pressure of the rabbit model of the VX2 tumor using a 64-slice perfusion CT and to compare the results with that obtained using the oxygen microelectrode method. Perfusion CT was performed for 45 successfully constructed rabbit models of a VX2 brain tumor. The perfusion values of the brain tumor region of interest, the blood volume (BV), the time to peak (TTP) and the peak enhancement intensity (PEI) were measured. The results were compared with the partial pressure of oxygen (PO2) of that region of interest obtained using the oxygen microelectrode method. The perfusion values of the brain tumor region of interest in 45 successfully constructed rabbit models of a VX2 brain tumor ranged from 1.3–127.0 (average, 21.1 ± 26.7 ml/min/ml); BV ranged from 1.2–53.5 ml/100g (average, 22.2 ± 13.7 ml/100g); PEI ranged from 8.7–124.6 HU (average, 43.5 ± 28.7 HU); and TTP ranged from 8.2–62.3 s (average, 38.8 ± 14.8 s). The PO2 in the corresponding region ranged from 0.14–47 mmHg (average, 16 ± 14.8 mmHg). The perfusion CT positively correlated with the tumor PO2, which can be used for evaluating the tumor hypoxia in clinical practice. (author)

  6. Wound healing in below-knee amputations in relation to skin perfusion pressure

    International Nuclear Information System (INIS)

    In 60 below-knee amputations the healing of the stumps was correlated with the local skin perfusion pressure (SPP) measured preoperatively as the external pressure required to stop isotope washout using 131I- or 125I--antipyrine mixed with histamine. Of the eight cases with an SPP below 20 mmHg, no less than six (75 per cent) failed to heal and required reamputation at the above-knee level. Of the 12 cases with an SPP between 20 and 30 mmHg four cases (33 per cent) failed to heal but of the 40 cases with an SPP above 30 mmHg, there were only four cases (10 per cent) which did not heal. The difference in failure rate is highly significant (P<0.01). Four out of 30 diabetic patients required reamputation as against 10 out of 30 non-diabetics (0.05< P<0.10) The average SPP was higher in the diabetic group: 57 mmHg (range 18-93 mmHg) compared with 34 mmHg (range 8-68 mmHg) in the non-diabetic group (P<0.001). The postoperative SPP measured on the stumps was on average 8 mmHg higher than the preoperative SPP (P<0.001). The increase took place mainly in stumps with an SPP above 20 mmHg explaining why the preoperative SPP values related so closely to the postoperative clinical course. We conclude that a low SPP can be used to predict ischaemic wound complications, leading to reamputation at a higher level. (author)

  7. Effects of arterial and venous volume infusion on coronary perfusion pressures during canine CPR.

    Science.gov (United States)

    Gentile, N T; Martin, G B; Appleton, T J; Moeggenberg, J; Paradis, N A; Nowak, R M

    1991-08-01

    Intraarterial (IA) volume infusion has been reported to be more effective than intravenous (IV) infusion in treating cardiac arrest due to exsanguination. A rapid IA infusion was felt to raise intraaortic pressure and improve coronary perfusion pressure (CPP). The purpose of this study was to determine if IA or IV volume infusion could augment the effect of epinephrine on CPP during CPR in the canine model. Nineteen mongrel dogs with a mean weight of 26.3 +/- 4.2 kg were anesthetized and mechanically ventilated. Thoracic aortic (Ao), right atrial (RA) and pulmonary artery catheters were placed for hemodynamic monitoring. Additional Ao and central venous catheters were placed for volume infusion. Ventricular fibrillation was induced and Thumper CPR was begun after 5 min (t = 5). At t = 10, all dogs received 45 micrograms/kg IV epinephrine. Six animals received epinephrine alone (EPI). Five dogs received EPI plus a 500 cc bolus of normal saline over 3 min intravenously (EPI/IV). Another group (n = 8) received EPI plus the same fluid bolus through the aortic catheter (EPI/IA). Resuscitation was attempted at t = 18 using a standard protocol. There was a significant increase in CPP over baseline in all groups. The changes in CPP from baseline induced by EPI, EPI/IV and EPI/IA were 20.6 +/- 3.7, 22.8 +/- 4.2 and 22.2 +/- 2.4 mmHg, respectively. Volume loading did not augment the effect of therapeutic EPI dosing. By increasing both preload and afterload, volume administration may in fact be detrimental during CPR. PMID:1658894

  8. The effects of posture, airway pressure and anesthesia on regulation of the regional ventilation and perfusion distribution in healthy humans

    OpenAIRE

    Nyrén, Sven

    2010-01-01

    Gas exchange has been observed to vary with posture in adult respiratory distress syndrome (ARDS) patients. In this thesis, the effect of posture on theregional distribution of ventilation (V) and perfusion (Q) in the lungs under normal breathing with and without continuous positive airway pressure (CPAP) and during general anesthesia with mechanical ventilation was studied. Additionally, endogenously produced nitric oxide (NO) may influence the effect of posture on the Q di...

  9. A study on the application of CT perfusion and CT angiography with 64-slice spiral CT in the evaluation of internal carotid artery and middle cerebral artery stenosis and occlusion

    International Nuclear Information System (INIS)

    Objective: To evaluate clinical application of combined cerebral CT perfusion (CTP) with head and neck CT angiography (CTA) using 64-slice spiral CT on the cerebral ischemia caused by the stenosis or occlusion of internal carotid artery (ICA) and middle cerebral artery (MCA). Methods: The sixty nine patients with unilateral or bilateral ICA and MCA stenosis or occlusion confirmed by digital subtraction angiography underwent head plain CT scan, cerebral CTP, and head and neck CTA using 64-slice spiral CT. Ten normal adults served as control. To discriminate the ischemic foci, the parameter maps of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTF) and time to peak (TTP) were obtained. Results: Among the patients with unilateral ICA stenosis or occlusion diagnosed by CTA, abnormal perfusion was found only in the watershed zone in 5 cases, both the MCA territory and the watershed zone were involved in 10 cases. Of 12 patients with severe unilateral ICA stenosis and occlusion, CBF values of the watershed zone in nonsymptmatic and symptomatic sides were(41±9) and (38±8) ml· 100 g-1·min-1 respectively (t=2.08, P>0.05), the MTT values were (5.2±1.1) and (10.9±2.6) s, respectively (t=7.24, P<0.01). Thirteen patients with severe bilateral ICA stenosis or occlusion diagnosed by CTA had perfusion abnormalities in the both the MCA territory and the watershed zone. Of 25 patients with unilateral MCA stenosis, 4 patients were normal in CT perfusion, 17 patients had perfusion abnormalities in MCA territory, and 4 patients had perfusion abnormalities in both MCA territory and the watershed zone. Twelve patients with severe bilateral MCA stenosis diagnosed by CTA had perfusion abnormalities in both the MCA territory and the watershed zone. Compared to normal control, the MTF and TTP were increased, the CBF was decreased, and the CBV in MCA territory and the watershed zone at the symptomatic side was increased. Conclusion: The combined examination

  10. Optical clearing agent perfusion enhancement via combination of microneedle poration, heating and pneumatic pressure

    OpenAIRE

    Damestani, Y; Melakeberhan, B; Rao, MP; Aguilar, G

    2014-01-01

    Background and Objective Optical clearing agents (OCAs) have shown promise for increasing the penetration depth of biomedical lasers by temporarily decreasing optical scattering within the skin. However, their translation to the clinic has been constrained by lack of practical means for effectively perfusing OCA within target tissues in vivo. The objective of this study was to address this limitation through combination of a variety of techniques to enhance OCA perfusion, including heating of...

  11. Association of brain amyloid-β with cerebral perfusion and structure in Alzheimer's disease and mild cognitive impairment.

    Science.gov (United States)

    Mattsson, Niklas; Tosun, Duygu; Insel, Philip S; Simonson, Alix; Jack, Clifford R; Beckett, Laurel A; Donohue, Michael; Jagust, William; Schuff, Norbert; Weiner, Michael W

    2014-05-01

    Patients with Alzheimer's disease have reduced cerebral blood flow measured by arterial spin labelling magnetic resonance imaging, but it is unclear how this is related to amyloid-β pathology. Using 182 subjects from the Alzheimer's Disease Neuroimaging Initiative we tested associations of amyloid-β with regional cerebral blood flow in healthy controls (n = 51), early (n = 66) and late (n = 41) mild cognitive impairment, and Alzheimer's disease with dementia (n = 24). Based on the theory that Alzheimer's disease starts with amyloid-β accumulation and progresses with symptoms and secondary pathologies in different trajectories, we tested if cerebral blood flow differed between amyloid-β-negative controls and -positive subjects in different diagnostic groups, and if amyloid-β had different associations with cerebral blood flow and grey matter volume. Global amyloid-β load was measured by florbetapir positron emission tomography, and regional blood flow and volume were measured in eight a priori defined regions of interest. Cerebral blood flow was reduced in patients with dementia in most brain regions. Higher amyloid-β load was related to lower cerebral blood flow in several regions, independent of diagnostic group. When comparing amyloid-β-positive subjects with -negative controls, we found reductions of cerebral blood flow in several diagnostic groups, including in precuneus, entorhinal cortex and hippocampus (dementia), inferior parietal cortex (late mild cognitive impairment and dementia), and inferior temporal cortex (early and late mild cognitive impairment and dementia). The associations of amyloid-β with cerebral blood flow and volume differed across the disease spectrum, with high amyloid-β being associated with greater cerebral blood flow reduction in controls and greater volume reduction in late mild cognitive impairment and dementia. In addition to disease stage, amyloid-β pathology affects cerebral blood flow across the span from controls to

  12. Influence of Exercise Modality on Cerebral-Ocular Hemodynamics and Pressures

    Science.gov (United States)

    Crowell, Brent; Martin, David; Goetchius, Elizabeth; Gonzales, Rebecca; Matz, Timothy; Ploutz-Snyder, Robert; Stenger, Michael; Ploutz-Snyder, Lori; Scott, Jessica

    2016-01-01

    Introduction: (a) Exercise training is beneficial for cardiac, muscle, and bone health, however, its effects on the development of visual impairment due to intracranial pressure (VIIP) remain controversial, (b) Resistive exercise without a Valsalva has been shown to increase intracranial pressure (ICP) by 3 mmHg, while with a Valsalva the increase is 18 mmHg, (c) Similar increases in intraocular pressure (IOP) have been observed during weight lifting, (d) Aerobic exercise also induces hemodynamic changes that impact ICP and IOP. During moderate-intensity exercise increases in cerebral blood flow and velocity occur, suggesting that moderate-intensity exercise could further increase intracranial blood volume and therefore ICP; and (e) Importantly, however, it is unknown how regional differences in cerebrovascular hemodynamics impact ocular pressure and global cerebral inflow and outflow during exercise with a cephalad fluid shift.

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  14. Closed-loop control of renal perfusion pressure in physiological experiments.

    Science.gov (United States)

    Campos-Delgado, D U; Bonilla, I; Rodríguez-Martínez, M; Sánchez-Briones, M E; Ruiz-Hernández, E

    2013-07-01

    This paper presents the design, experimental modeling, and control of a pump-driven renal perfusion pressure (RPP)-regulatory system to implement precise and relatively fast RPP regulation in rats. The mechatronic system is a simple, low-cost, and reliable device to automate the RPP regulation process based on flow-mediated occlusion. Hence, the regulated signal is the RPP measured in the left femoral artery of the rat, and the manipulated variable is the voltage applied to a dc motor that controls the occlusion of the aorta. The control system is implemented in a PC through the LabView software, and a data acquisition board NI USB-6210. A simple first-order linear system is proposed to approximate the dynamics in the experiment. The parameters of the model are chosen to minimize the error between the predicted and experimental output averaged from eight input/output datasets at different RPP operating conditions. A closed-loop servocontrol system based on a pole-placement PD controller plus dead-zone compensation was proposed for this purpose. First, the feedback structure was validated in simulation by considering parameter uncertainty, and constant and time-varying references. Several experimental tests were also conducted to validate in real time the closed-loop performance for stepwise and fast switching references, and the results show the effectiveness of the proposed automatic system to regulate the RPP in the rat, in a precise, accurate (mean error less than 2 mmHg) and relatively fast mode (10-15 s of response time). PMID:23358945

  15. Epileptic patterns of local cerebral metabolism and perfusion in man determined by emission computed tomography of /sup 18/FDG and /sup 13/NH/sub 3/

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, D.E.; Engel, J. Jr.; Phelps, M.E.; Selin, C.

    1979-01-01

    Seventeen patients with partial epilepsy had EEG monitoring concurrent with cerebral emission computed tomography (ECT) after /sup 18/F-fluorodeoxyglucose (/sup 18/FDG) and /sup 13/N-ammonia were given intravenously as indicators of local cerebral glucose utilization (LCMR/sub glc/) and relative perfusion, respectively. In 12 of 15 patients who had unilateral or focal electrical abnormalities, interictal /sup 18/FDG scan patterns clearly showed localized regions of decreased (20% to 50%) LCMR/sub glc/, which correlated anatomically with the eventual EEG localization. These hypometabolic zones appeared normal on x-ray computed tomography in all but three patients and were unchanged on scans repeated on different days. In 5 of 6 patients who underwent temporal lobectomy, the interictal /sup 18/FDG scan correctly detected the pathologically confirmed lesion as a hypometabolic zone, and removal of the lesion site resulted in marked clinical improvement. In contrast, the ictal /sup 18/FDG scan patterns clearly showed foci of increased (82% to 130%) LCMR/sub glc/, which correlated temporally and anatomically with ictal EEG spike foci and were within the zones of interictal hypometabolism (3 studies in 2 patients). /sup 13/NH/sub 3/ distributions paralleled /sup 18/FDG increases and decreases in abnormal zones, but /sup 13/NH/sub 3/ differences were of lesser magnitude. When the relationship of /sup 13/NH/sub 3/ uptake to local blood flow found in dog brain was applied as a correction to the patients' /sup 13/NH/sub 3/ scan data, local alterations in perfusion and glucose utilization were usually matched, both in the interictal and ictal states.

  16. Role of 99mTc-ECD brain SPECT in the detection of cerebral perfusion abnormality in cases of Attention Deficit Hyperactivity Disorder

    International Nuclear Information System (INIS)

    Aim: A randomized placebo controlled drug trial with Mentat, a herbal pharmacological agent, was initiated in January 2000 in the department of pediatrics at AIIMS, New Delhi, to compare the efficacy of Mentat with a placebo in school children with Attention Deficit Hyperactivity Disorder (ADHD). Materials and Methods: Contact was established with 12 Public schools in Delhi, to identify poor performers in classes I-V (age 6-12 yrs.). About 195 children with poor school performance were recruited in the study. They were screened for causes of poor performance, which included attention problems, hyperactivity, behavior problems, emotional problems, mental sub-normality and learning disability. ADHD suspected children were identified using the Malin's WISC, Connor's rating scale, Problem Behavior checklist, Bender Gestalt test and some sub tests of the Kaufman's Assessment Battery for Children (K-ABC). Sixty children diagnosed as ADHD (using DSM-IV criteria), with an IQ between 90-110, were enrolled into the study. Of the 60 children randomized in the study, 30 received Mentat and 30 received an identical looking placebo. The drug/Placebo was given for a six-month period. 99mTC-ECD brain SPECT was performed in a subset of 34 children with ADHD. Results: Abnormal cerebral perfusion was seen in 23/34; thalamic hypoperfusion in 11, basal ganglia hypoperfusion in 9, thalamus and basal ganglia hypoperfusion in 2 and basifrontal hypoperfusion in 1. So far, in ten children with abnormal pretreatment scans, post treatment scans have also been done. In mentat group, 2/5 children showed normalization of perfusion abnormality after treatment whereas in placebo group, 1/5. Conclusion: This study suggests that there is selective focal cerebral hypoperfusion in cases of ADHD and 99mTc-ECD brain SPECT can be used for evaluation and further monitoring of therapeutic outcome in such cases

  17. Prediction of clinical outcome with baseline and 24-hour perfusion CT in acute middle cerebral artery territory ischemic stroke treated with intravenous recanalization therapy

    International Nuclear Information System (INIS)

    We sought to determine whether Alberta Stroke Program Early CT Scores (ASPECTS) derived from baseline noncontrast CT (NCCT) and perfusion CT (CTP) imaging maps can predict clinical outcome after recanalization therapy in acute ischemic stroke of the middle cerebral artery (MCA) territory and whether changes in the ASPECTS from baseline to 24 h after recanalization therapy can help predict clinical outcome. We retrospectively studied consecutive patients with acute ischemic stroke of the MCA territory treated with intravenous tissue plasminogen activator (t-PA) or abciximab within 6 h of symptom onset. We performed NCCT and CTP before and 24 h after intravenous t-PA or abciximab treatment and determined the ASPECTS and the changes in the ASPECTS from baseline to 24 h. A favorable outcome was defined as a modified Rankin scale score of 0 or 1 at 3 months. During the 18-month study period 44 patients were studied. In multivariate logistic regression analysis, the cerebral blood volume (CBV) ASPECTS (OR 1.80, 95% CI 1.10 to 2.93) at baseline and the increase in cerebral blood flow (CBF) ASPECTS (OR 1.68, 95% CI 1.13 to 2.50) from baseline to 24 h were associated with a favorable outcome. The cutoff values for a favorable outcome using receiver operating characteristic curves were 8 and 1, respectively. When the CBV ASPECTS at baseline was 8 or more, its positive predictive value was only 58.1%. When the CBV ASPECTS at baseline was 8 or more and the increase in CBF ASPECTS from baseline to 24 h was 1 or more, the positive predictive value was 100% and the negative predictive value was 74.2%. The CBV ASPECTS derived from baseline CTP maps was found to be predictive of a favorable outcome, but its positive predictive value was suboptimal. The change in the CBF ASPECTS from baseline to 24 h after treatment was helpful in predicting outcome. (orig.)

  18. Individual susceptibility to hypoperfusion and reductions in exercise performance when perfusion pressure is reduced: evidence for vasodilator phenotypes

    OpenAIRE

    Bentley, Robert F; Kellawan, J. Mikhail; Moynes, Jackie S.; Poitras, Veronica J; Walsh, Jeremy J.; Tschakovsky, Michael E

    2014-01-01

    The primary objective of this study was to determine whether cardiovascular compensatory response phenotypes exist in the face of a reduced perfusion pressure challenge to exercising muscle oxygen delivery (O2D), and whether these responses might be exercise intensity (EI) dependent. Ten healthy men (19.5 ± 0.4 yr) completed two trials of progressive forearm isometric handgrip exercise to exhaustion (24.5 N increments every 3.5 min) in each of forearm above and below heart level [forearm arte...

  19. Heat-washout measurements compared to distal blood pressure and perfusion in orthopaedic patients with foot ulcers

    DEFF Research Database (Denmark)

    Midttun, Mette; Azad, B.B.S.; Broholm, R;

    2015-01-01

    Distal blood pressure and local skin perfusion pressure were compared to measurement of blood flow rate (BFR) measured by the heat-washout method in orthopaedic patients with and without diabetes, all with a foot ulcer in one foot, compared to healthy controls. The correlation was good between heat......-washout and distal blood pressure in patients with diabetes with and without an ulcer (P = 0·024 and 0·059, respectively). The correlation was weak in patients without diabetes with and without an ulcer, most probably due to power problems (P = 0·118 and 0·116, respectively). The correlation in the healthy...... oxygen from the surrounding tissue, and therefore, measurements are easier made in these subjects. BFR in the first toe increased significantly in all patients when the foot was moved from heart level to 50 cm below heart level (P = between 0·03 and 0·05) as previously seen in patients with claudication...

  20. Testing impact of perinatal inflammation on cerebral autoregulation in preterm neonates

    DEFF Research Database (Denmark)

    Hahn, Gitte Holst

    2013-01-01

    between inflammation and brain injury. We used an apparently well established non-invasive method based on frequency analysis between spontaneous changes in arterial blood pressure and cerebral oxygenation as measured with near-infrared spectroscopy. It turned out that the methodology was weak. This led...... us to evaluate the precision and validity of this method. We monitored 22 preterm neonates and demonstrated that reliable detection of impaired cerebral autoregulation requires several hours of monitoring. However, weighting measurements with large variations in blood pressure in favour of those with...... preterm infants and experimental studies in newborn piglets. Maintaining adequate cerebral perfusion is critical to avoid brain injury. In healthy neonates, cerebral autoregulation ensures an almost unchanged cerebral perfusion within a narrow range of arterial blood pressures. When autoregulation is...

  1. Cerebral perfusion and metabolism in relation to the evolution of unilateral spatial neglect due to cerebral infarction. Contribution of bilateral hemispheres in appearance and recovery

    International Nuclear Information System (INIS)

    To investigate the mechanisms underlying the evolution of unilateral spatial neglect (USN) due to cerebral infarction, the cerebral oxygen metabolism was measured quantitatively by positron emission tomography (PET). Out of 189 consecutive patients with right hemisphere lesions who underwent PET, we recruited 13 patients (group A) who exhibited USN at the time of PET examination, 11 patients (group B) who had already recovered from USN, and 27 patients (group C) with right hemisphere infarction who failed to present with USN throughout. Eight normal volunteers (group NV) served as controls. Statistical comparisons were performed on the local values of the cerebral metabolic rate of oxygen (CMRO2) from the region of interest (ROI) in the right dorsolateral frontal lobe, superior temporal gyrus, inferior parietal lobule, cingulate gyrus, basal ganglia and thalamus which are associated with USN. We also obtained CMRO2 values for the contralateral areas. As compared with group C or NV, there were significant decreases in CMRO2 in the right frontal, right temporal and right parietal lobes, right basal ganglia, right thalamus and bilateral cingulate gyri in groups A and B. Except for the left inferior parietal lobule, no significant differences in regional CMRO2 were noted between groups A and B. These findings indicate that extensive right hemisphere lesions may produce USN, but no specific brain region is associated with its recovery. Different from aphasics, no definite relationship is evident between recovery from USN and the role of the contralateral left hemisphere. This could be explained partly by the complexity of the pathogenetic mechanisms underlying USN. (author)

  2. Hypertension, blood pressure, cognition and cerebral blood flow in the cohort of "Men born 1914"

    OpenAIRE

    Reinprecht, Faina

    2006-01-01

    "Men born 1914" is a population based cohort study of the epidemiology of cardiovascular disease. Five hundred men, born 1914, were examined at the age of 68 and 185 of them were re-examined at 81 years of age. Examination included a medical and a psychological investigation, ultrasonographic measurement of carotid arteries, 24-hour ambulatory blood pressure monitoring, regional cerebral blood flow, and cardiovascular risk factors. It is well known that hypertension plays a major et...

  3. Cerebral perfusion inhomogeneities in schizophrenia demonstrated with single photon emission computed tomography and Tc99m-hexamethylpropyleneamineoxim

    International Nuclear Information System (INIS)

    Cerebral blood flow was measured in relative terms with Tc99m-hexamethylpropyleneamineoxim (HMPAO) and single photon emission computed tomography (SPECT) in 28 female schizophrenic patients (20 acute and 8 chronic) classified according to DSM-III. Eleven normals served as controls. The acute patients were classified according to positive and negative symptoms. Patients with predominantly positive symptoms showed by and large normal and homogeneous cerebral isotope uptake. Those with negative symptoms, and the chronic patients, showed inhomogeneous tracer uptake with multiple regions of hypoperfusion in slices 4-6 cm above the orbitomeatal line. The findings support in principle the notion that schizophrenia with negative or chronic symptoms does not affect the whole brain homogeneously. Brain imaging with Tc99m-HMPAO and SPECT might be used to distinguish various types of schizophrenia. (author)

  4. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping;

    2009-01-01

    In the present study, we hypothesized that changes in perfusion pressure result in altered expression of mRNA and protein encoding for the ETA-, ETB-, AT1- and AT2-receptors in rat mesenteric vessels. Segments of the rat mesenteric artery were cannulated with glass micropipettes, pressurized and...... luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor m......RNA content, or immersed in a fixative solution, dehydrated, frozen, cut in a cryostat and immunohistology stained for ET- and AT-receptor protein. The mRNA expressions of ETB and of AT2 were significantly enhanced in vessels exposed to high perfusion pressure, compared with normal and no perfusion pressure...

  5. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping;

    2009-01-01

    In the present study, we hypothesized that changes in perfusion pressure result in altered expression of mRNA and protein encoding for the ETA-, ETB-, AT1- and AT2-receptors in rat mesenteric vessels. Segments of the rat mesenteric artery were cannulated with glass micropipettes, pressurized and...

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

    International Nuclear Information System (INIS)

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

  7. Cerebral metabolism and perfusion in MR-negative individuals with refractory focal epilepsy assessed by simultaneous acquisition of (18)F-FDG PET and arterial spin labeling.

    Science.gov (United States)

    Boscolo Galazzo, Ilaria; Mattoli, Maria Vittoria; Pizzini, Francesca Benedetta; De Vita, Enrico; Barnes, Anna; Duncan, John S; Jäger, Hans Rolf; Golay, Xavier; Bomanji, Jamshed B; Koepp, Matthias; Groves, Ashley M; Fraioli, Francesco

    2016-01-01

    The major challenge in pre-surgical epileptic patient evaluation is the correct identification of the seizure onset area, especially in MR-negative patients. In this study, we aimed to: (1) assess the concordance between perfusion, from ASL, and metabolism, from (18)F-FDG, acquired simultaneously on PET/MR; (2) verify the utility of a statistical approach as supportive diagnostic tool for clinical readers. Secondarily, we compared (18)F-FDG PET data from the hybrid PET/MR system with those acquired with PET/CT, with the purpose of validate the reliability of (18)F-FDG PET/MR data. Twenty patients with refractory focal epilepsy, negative MR and a defined electro-clinical diagnosis underwent PET/MR, immediately followed by PET/CT. Standardized uptake value ratio (SUVr) and cerebral blood flow (CBF) maps were calculated for PET/CT-PET/MR and ASL, respectively. For all techniques, z-score of the asymmetry index (zAI) was applied for depicting significant Right/Left differences. SUVr and CBF images were firstly visually assessed by two neuroimaging readers, who then re-assessed them considering zAI for reaching a final diagnosis. High agreement between (18)F-FDG PET/MR and ASL was found, showing hypometabolism and hypoperfusion in the same hemisphere in 18/20 patients, while the remaining were normal. They were completely concordant in 14/18, concordant in at least one lobe in the remaining. zAI maps improved readers' confidence in 12/20 and 15/20 patients for (18)F-FDG PET/MR and ASL, respectively. (18)F-FDG PET/CT-PET/MR showed high agreement, especially when zAI was considered. The simultaneous metabolism-perfusion acquisition provides excellent concordance on focus lateralisation and good concordance on localisation, determining useful complementary information. PMID:27222796

  8. Assessment of cerebral perfusion and cerebrovascular reserve in insulin-dependent diabetic patients without central neurological symptoms by means of 99mTc-HMPAO SPET with acetazolamide

    International Nuclear Information System (INIS)

    The detection of subclinical abnormalities in cerebral blood flow could be of great value in identifying diabetic patients at risk of stroke. The aim of this study was to assess the contribution of semiquantified post-acetazolamide technetium-99m hexamethylpropylene amine oxime single-photon emission tomography (99mTc-HMPAO SPET) in 15 diabetic patients with no clinical history of central neurological disease. After baseline 99mTc-HMPAO SPET, a second SPET scan was acquired after activation of the cerebrovascular reserve (CVR) with an injection of 1 g of acetazolamide (post-ACZ SPET). Semiquantitative analysis was made in 16 regions of interest (ROIs) drawn for each of the three supratentorial slices selected, and in two ROIs in the infratentorial slice. The CVR was calculated in each ROI by subtracting the decay-corrected baseline images from those obtained in the post-ACZ SPET and expressed as the percent increase in the average counts between the two scans. Baseline perfusion and CVR values in the study group were compared with the corresponding values in a control group. Of 750 cortical ROIs studied, 332 showed a decreased CVR (44.3%). The baseline perfusion SPET study showed hypoperfusion in 65 ROIs (8.6%) and hyperperfusion in 56 (7.4%). Of the 65 hypoperfused regions, 66.2% had a normal CVR and 33.8% had a decreased CVR, whereas of the 56 hyperperfused regions, 51.8% had a CVR within normal limits and 48.2% showed a decreased CVR. In conclusion, in comparison with baseline 99mTc-HMPAO SPET, the ACZ activation test provided additional information in the study of cerebrovascular impairment, and allowed characterisation of the subclinical abnormalities in the population studied. The technique may therefore prove useful in evaluating future preventive strategies for stroke in diabetic patients. (orig.)

  9. Estimation of cerebral vascular tone during exercise; evaluation by critical closing pressure in humans

    DEFF Research Database (Denmark)

    Ogoh, Shigehiko; Brothers, R Matthew; Jeschke, Monica;

    2010-01-01

    . In addition, the increases in CCP were related to the increases in plasma noradrenaline concentrations (right, P = 0.001; left, P = 0.025) and decreases in the partial pressure of arterial carbon dioxide (right, P = 0.008; left, P = 0.086), but not to changes in mean arterial pressure (right, P = 0.......282; left, P = 0.564) or adrenaline concentrations (right, P = 0.138; left, P = 0.108). We consider that an exercise-induced increase in cerebral vascular tone serves to protect the blood-brain barrier from the exercise-induced hypertension....

  10. Cerebral gliomas: prospective comparison of multivoxel 2D chemical-shift imaging proton MR spectroscopy, echoplanar perfusion and diffusion-weighted MRI

    International Nuclear Information System (INIS)

    Developments in MRI have made it possible to use diffusion-weighted MRI, perfusion MRI and proton MR spectroscopy (MRS) to study lesions in the brain. We evaluated whether these techniques provide useful, complementary information for grading gliomas, in comparison with conventional MRI. We studied 17 patients with histologically verified gliomas, adding multivoxel proton MRS, echoplanar diffusion and perfusion MRI the a routine MRI examination. The maximum relative cerebral blood volume (CBV), minimum apparent diffusion coefficient (ADC) and metabolic peak area ratios in proton MRS were calculated in solid parts of tumours on the same slice from each imaging data set. The mean minimum ADC of the 13 high-grade gliomas (0.92±0.27 x 10-3 mm2/s) was lower than that of the four low-grade gliomas (1.28±0.15 x 10-3 mm2/s) (P<0.05). Means of maximum choline (Cho)/N-acetylaspartate (NAA), Cho/creatine (Cr), Cho/Cr in normal brain (Cr-n) and minimum NAA/Cr ratios were 5.90±2.62, 4.73±2.22, 2.66±0.68 and 0.40±0.06, respectively, in the high-grade gliomas, and 1.65±1.37, 1.84±1.20, 1.61±1.29 and 1.65±1.61, respectively, in the low-grade gliomas. Significant differences were found on spectroscopy between the high- and low-grade gliomas (P<0.05). Mean maximum relative CBV in the high-grade gliomas (6.10±3.98) was higher than in the low-grade gliomas (1.74±0.57) (P<0.05). Echoplanar diffusion, perfusion MRI and multivoxel proton MRS can offer diagnostic information, not available with conventional MRI, in the assessment of glioma grade. (orig.)

  11. Correlation between special brain area and blood perfusion in patients with cerebral infarction at convalescent period Feasibility for quantitative determination and estimation of learning and memory function

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Presently, clinic memory scale is used to evaluate learning memory ability in most studies,and the influence of difference in measurement condition of individuals exists.OBJECTIVE: To study the correlation between regional cerebral blood flow (rCBF) perfusion and learning memory function in special brain regions of patients with cerebral infarction at convalescent period,and to try to find out a method which can quantitatively evaluate learning ability.DESIGN: Case observation, and correlation analysis.SETTINGS: Shandong Institute for Behavioral Medicine; the Affiliated Hospital of Jining Medical College.PARTICIPANTS: Totally 70 patients with cerebral infarction admitted to Departtment of Neurology, Jining Medical College between January 2004 and December 2005 were involved. The involved patients, 58 male and 12 female, were averaged (52±3) years, and they were all right handed. They all met the diagnosis criteria instituted by the Fourth National Conference on Cerebrovascular Disease, and were confirmed as cerebral infarction by skull CT or MRI. Informed consents of detected items were obtained from all the patients and relatives.METHODS: When the patients were at convalescent period, their learning and memory ability were measured with" clinic memory scale (set A)". The 18 patients whose total mark over 100 were regarded as good learning memory function group; The 23 cases whose total mark less than 70 were regarded as poor learning memory function group. RCBF of hippocampus, nucleus amygdalae, temporal cortex and prefrontal lobe of patients between two groups were measured and compared by single photon emission computed tomography (SPECT). The total scores of the 18 good learning memory patients and 23 poor learning memory patients were taken as dependent variable Y, and their rCBFs of hippocampus, nucleus amygdale,temporal cortex and prefrontal lobe respectively as independent variable X for linear correlation analysis.MAIN OUTCOME MEASURES

  12. Multimodal Pressure-Flow Analysis: Application of Hilbert Huang Transform in Cerebral Blood Flow Regulation

    Directory of Open Access Journals (Sweden)

    Vera Novak

    2008-06-01

    Full Text Available Quantification of nonlinear interactions between two nonstationary signals presents a computational challenge in different research fields, especially for assessments of physiological systems. Traditional approaches that are based on theories of stationary signals cannot resolve nonstationarity-related issues and, thus, cannot reliably assess nonlinear interactions in physiological systems. In this review we discuss a new technique called multimodal pressure flow (MMPF method that utilizes Hilbert-Huang transformation to quantify interaction between nonstationary cerebral blood flow velocity (BFV and blood pressure (BP for the assessment of dynamic cerebral autoregulation (CA. CA is an important mechanism responsible for controlling cerebral blood flow in responses to fluctuations in systemic BP within a few heart-beats. The MMPF analysis decomposes BP and BFV signals into multiple empirical modes adaptively so that the fluctuations caused by a specific physiologic process can be represented in a corresponding empirical mode. Using this technique, we showed that dynamic CA can be characterized by specific phase delays between the decomposed BP and BFV oscillations, and that the phase shifts are significantly reduced in hypertensive, diabetics and stroke subjects with impaired CA. Additionally, the new technique can reliably assess CA using both induced BP/BFV oscillations during clinical tests and spontaneous BP/BFV fluctuations during resting conditions.

  13. Evaluation on the Therapeutic Effects of Digital Acupoint Pressure for Obstetric Spastic Cerebral Palsy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To probe the evaluation methods for effects of TCM treatment of cerebral palsy through clinical observation on the digital acupoint pressure in treating obstetric spastic cerebral palsy. From 1998-2003,40 cases of spastic cerebral palsy were treated with digital acupoint pressure therapy. Ten indexes including intelligence, language, salivation, hand-grasping, thumb-adduction, turnover, sitting, standing,walking, and scissors-gait were divided into the 4 grades of normal, mild abnormal, moderate abnormal,and severe abnormal (dysfunction), respectively marked as 6, 4, 2, and 0 point, with 2 points increased for improving each grade of each item after the treatment. Meanwhile, the ranges were recorded and evaluated before and after the treatment on shoulder-abduction, elbow-extension, wrist-extension,forearm-backward-rotation, hip-abduction, straight-leg-lifting, knee-extension, and ankle-dorsiflexion.Those with the improvement of 10° , 15° , 20° , 25° , and 30° in the range of movement of their contractured joints would obtain respectively 1, 2, 3, 4, and 5 points. There were significant differences before and after the treatment in the 18 items under observation except for intelligence, with obvious improvement shown after the treatment (P<0.01), the effective rate being 92.5%. The therapeutic criteria set in this research are well established in reflecting the functional improvements of the patient.

  14. Secondary decline of cerebral autoregulation is associated with worse outcome after intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Reinhard, Matthias; Neunhoeffer, Florian; Gerds, Thomas A;

    2010-01-01

    and 5 after ictus. Autoregulation was noninvasively measured from spontaneous fluctuations of blood pressure and middle cerebral artery flow velocity (assessed by transcranial Doppler) using the correlation coefficient index Mx. From the same signals, non-invasive cerebral perfusion pressure was......PURPOSE: Blood pressure management in acute intracerebral hemorrhage (ICH) relies on functioning cerebral autoregulation. The time course of autoregulation in acute ICH and its relation with clinical outcome are not known. METHODS: Twenty-six patients with spontaneous ICH were studied on days 1, 3...... related with lower Glasgow coma score, ventricular hemorrhage (both sides) and lower noninvasive cerebral perfusion pressure (ipsilateral). Increasing ipsilateral Mx between days 3 and 5 was related with lower Glasgow coma score and ventricular hemorrhage. In a multivariate analysis controlling for other...

  15. Value of perfusion-weighted MR imaging in the assessment of early cerebral alterations in neurologically asymptomatic HIV-1-positive and HCV-positive patients.

    Directory of Open Access Journals (Sweden)

    Joanna Bladowska

    Full Text Available BACKGROUND AND PURPOSE: Asymptomatic central nervous system (CNS involvement occurs in the early stage of the human immunodeficiency virus (HIV infection. It has been documented that the hepatitis C virus (HCV can replicate in the CNS. The aim of the study was to evaluate early disturbances in cerebral microcirculation using magnetic resonance (MR perfusion-weighted imaging (PWI in asymptomatic HIV-1-positive and HCV-positive patients, as well as to assess the correlation between PWI measurements and the clinical data. MATERIALS AND METHODS: Fifty-six patients: 17 HIV-1-positive non-treated, 18 HIV-1-positive treated with combination antiretroviral therapy (cART, 7 HIV-1/HCV-positive non-treated, 14 HCV-positive before antiviral therapy and 18 control subjects were enrolled in the study. PWI was performed with a 1.5T MR unit using dynamic susceptibility contrast (DSC method. Cerebral blood volume (CBV measurements relative to cerebellum (rCBV were evaluated in the posterior cingulated region (PCG, basal ganglia (BG, temporoparietal (TPC and frontal cortices (FC, as well as in white matter of frontoparietal areas. Correlations of rCBV values with immunologic data and liver histology activity index (HAI were analyzed. RESULTS: Significantly lower rCBV values were found in the right TPC and left FC as well as in PCG in HIV-1-positive naïve (p = 0.009; p = 0.020; p = 0.012, HIV-1 cART treated (p = 0.007; p = 0.009; p = 0.033, HIV-1/HCV-positive (p = 0.007; p = 0.027; p = 0.045 and HCV-positive patients (p = 0.010; p = 0.005; p = 0.045 compared to controls. HIV-1-positive cART treated and HIV-1/HCV-positive patients demonstrated lower rCBV values in the right FC (p = 0.009; p = 0.032, respectively and the left TPC (p = 0.036; p = 0.005, respectively, while HCV-positive subjects revealed lower rCBV values in the left TPC region (p = 0.003. We found significantly elevated rCBV values in BG in HCV-positive patients (p = 0.0002; p<0.0001 compared to

  16. Cerebral blood volume calculated by dynamic susceptibility contrast-enhanced perfusion MR imaging: preliminary correlation study with glioblastoma genetic profiles.

    Directory of Open Access Journals (Sweden)

    Inseon Ryoo

    Full Text Available PURPOSE: To evaluate the usefulness of dynamic susceptibility contrast (DSC enhanced perfusion MR imaging in predicting major genetic alterations in glioblastomas. MATERIALS AND METHODS: Twenty-five patients (M:F = 13∶12, mean age: 52.1±15.2 years with pathologically proven glioblastoma who underwent DSC MR imaging before surgery were included. On DSC MR imaging, the normalized relative tumor blood volume (nTBV of the enhancing solid portion of each tumor was calculated by using dedicated software (Nordic TumorEX, NordicNeuroLab, Bergen, Norway that enabled semi-automatic segmentation for each tumor. Five major glioblastoma genetic alterations (epidermal growth factor receptor (EGFR, phosphatase and tensin homologue (PTEN, Ki-67, O6-methylguanine-DNA methyltransferase (MGMT and p53 were confirmed by immunohistochemistry and analyzed for correlation with the nTBV of each tumor. Statistical analysis was performed using the unpaired Student t test, ROC (receiver operating characteristic curve analysis and Pearson correlation analysis. RESULTS: The nTBVs of the MGMT methylation-negative group (mean 9.5±7.5 were significantly higher than those of the MGMT methylation-positive group (mean 5.4±1.8 (p = .046. In the analysis of EGFR expression-positive group, the nTBVs of the subgroup with loss of PTEN gene expression (mean: 10.3±8.1 were also significantly higher than those of the subgroup without loss of PTEN gene expression (mean: 5.6±2.3 (p = .046. Ki-67 labeling index indicated significant positive correlation with the nTBV of the tumor (p = .01. CONCLUSION: We found that glioblastomas with aggressive genetic alterations tended to have a high nTBV in the present study. Thus, we believe that DSC-enhanced perfusion MR imaging could be helpful in predicting genetic alterations that are crucial in predicting the prognosis of and selecting tailored treatment for glioblastoma patients.

  17. CT Perfusion: applications in neuroimaging

    International Nuclear Information System (INIS)

    Full text: CT perfusion is a relatively new imaging technique that tracks the passage of a bolus dose of iodinated contrast medium through the intracranial vasculature and tissues. It allows both qualitative and quantitative analysis of cerebral perfusion parameters. The most common and significant neurological diseases (eg stroke and subarachnoid haemorrhage) can have a potentially significant impact on cerebral perfusion. Accurate analysis of cerebral perfusion affords a greater understanding of these diseases and provides further information regarding the timing and effects of intervention.We present a synopsis of our work to date on the clinical applications of CT perfusion in a variety of neurological disorders. A GE High Speed Cti system (GE Medical Systems, Milwaukee, US) with Perfusion 2 software (GE Medical System, Milwaukee, US) was used to obtain cerebral perfusion parameter maps and quantitative values of perfusion in specific regions of interest using an Advantage Windows 4.0 workstation (GE Medical Systems, Milwaukee, US). Depending on the clinical scenario, between one and three levels of the brain were examined to survey the appropriate level of interest. For example, patients with subarachnoid haemorrhage had imaging through the basal ganglia and the watershed areas. Other areas where we have applied this technique are tumour imaging, brain death and chronic cerebral ischaemia. CT perfusion is a widely applicable technique that is both quantitative and reproducible in a wide variety of clinical settings. It can be performed as part of the routine imaging of patients, and may be used in patients who are moderately un-cooperative, as the study takes little time to perform. CT perfusion shows significant promise in improving our understanding of many neurovascular conditions and in monitoring the effects of clinical interventions. Copyright (2002) Blackwell Science Pty Ltd

  18. Microdialysis Assessment of Cerebral Perfusion during Cardiac Arrest, Extracorporeal Life Support and Cardiopulmonary Resuscitation in Rats – A Pilot Trial

    Science.gov (United States)

    Schober, Andreas; Warenits, Alexandra M.; Testori, Christoph; Weihs, Wolfgang; Hosmann, Arthur; Högler, Sandra; Sterz, Fritz; Janata, Andreas; Scherer, Thomas; Magnet, Ingrid A. M.; Ettl, Florian; Laggner, Anton N.; Herkner, Harald; Zeitlinger, Markus

    2016-01-01

    Cerebral metabolic alterations during cardiac arrest, cardiopulmonary resuscitation (CPR) and extracorporeal cardiopulmonary life support (ECLS) are poorly explored. Markers are needed for a more personalized resuscitation and post—resuscitation care. Aim of this study was to investigate early metabolic changes in the hippocampal CA1 region during ventricular fibrillation cardiac arrest (VF-CA) and ECLS versus conventional CPR. Male Sprague-Dawley rats (350g) underwent 8min untreated VF-CA followed by ECLS (n = 8; bloodflow 100ml/kg), mechanical CPR (n = 18; 200/min) until return of spontaneous circulation (ROSC). Shams (n = 2) were included. Glucose, glutamate and lactate/pyruvate ratio were compared between treatment groups and animals with and without ROSC. Ten animals (39%) achieved ROSC (ECLS 5/8 vs. CPR 5/18; OR 4,3;CI:0.7–25;p = 0.189). During VF-CA central nervous glucose decreased (0.32±0.1mmol/l to 0.04±0.01mmol/l; p<0.001) and showed a significant rise (0.53±0.1;p<0.001) after resuscitation. Lactate/pyruvate (L/P) ratio showed a 5fold increase (31 to 164; p<0.001; maximum 8min post ROSC). Glutamate showed a 3.5-fold increase to (2.06±1.5 to 7.12±5.1μmol/L; p<0.001) after CA. All parameters normalized after ROSC with no significant differences between ECLS and CPR. Metabolic changes during ischemia and resuscitation can be displayed by cerebral microdialysis in our VF-CA CPR and ECLS rat model. We found similar microdialysate concentrations and patterns of normalization in both resuscitation methods used. Institutional Protocol Number: GZ0064.11/3b/2011 PMID:27175905

  19. Pre and post operative evaluation of the perfusion reserve by acetazolamide [sup 99m]Tc-HMPAO SPECT in patients with chronic occlusive cerebral arteries. A comparative study with PET

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo; Ichiya, Yuichi; Sasaki, Masayuki; Akashi, Yuko; Yoshida, Tsuyoshi; Fukumura, Toshimitsu; Masuda, Kouji; Fujii, Kiyotaka; Fukui, Masashi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1994-09-01

    We studied the pre and post-operative perfusion reserve using Diamox [sup 99m]Tc-HMPAO SPECT in 7 patients with chronic occlusive cerebral arteries and then compared the results with PET. STAMCA anastomosis was performed on 5 patients, while a carotid endarterectomy was done on 2 patients. The cerebral blood flow, the vascular response to CO[sub 2] or Diamox, the oxygen extraction fraction and transit time (CBV/CBF) were measured by PET. In the pre-operative state, the visual evaluations for hypoperfusion area at rest agreed in 5 out of 7 patients in HMPAO SPECT and PET studies. In the remaining 2 patients, hypoperfusion areas were only detected in the PET study. The pre-operative evaluation of perfusion reserve agreed in 2 patients. In the remaining 5 patients, 3 patients showed definite positive (++) in PET and positive (+) in HMPAO SPECT, and one patient showed positive (+) in PET and negative (-) in HMPAO SPECT. The post-operative change of hypoperfusion areas well agreed in HMPAO SPECT and PET studies. However, the change of perfusion reserve was underestimated in HMPAO SPECT compared with PET. In the semiquantitative and quantitative analyses, the count rate ratios (affected/unaffected side) in HMPAO SPECT were apparently higher than those of CBF in PET. The postoperative change of the count rate ratios in HMPAO SPECT were smaller than those of CBF in PET. There was no significant correlation between the change in the ratio of the HMPAO SPECT after the administration of Diamox and the oxygen extraction fraction, and it was thus thought to be impossible to predict the areas with an increased oxygen extraction fraction. Thus, Diamox HMPAO SPECT may underestimate the areas of hypoperfusion or decrease in perfusion reserve when compared with PET. We should consider these limitations in the evaluation of pre and post operative cerebral hemodynamics. (author).

  20. Comparison Between Cerebral Tissue Oxygen Tension and Energy Metabolism in Experimental Subdural Hematoma

    DEFF Research Database (Denmark)

    Nielsen, Troels Halfeld; Engell, Susanne I; Johnsen, Rikke Aagaard;

    2011-01-01

    . Intracranial pressure (ICP) was monitored in the "good-side." RESULTS: ICP, cerebral perfusion pressure (CPP), PbtO(2), glucose, lactate, pyruvate, lactate-pyruvate ratio (LP ratio), glutamate, and glycerol were recorded at baseline (60 min) and post trauma (360 min). After the creation of the ASDH, PbtO(2...

  1. The influence of tobacco smoking on the relationship between pressure and flow in the middle cerebral artery in humans.

    Directory of Open Access Journals (Sweden)

    Karen C Peebles

    Full Text Available BACKGROUND: Cigarette smoking is associated with an increased risk of stroke but the mechanism is unclear. The study examined whether acute and chronic cigarette smoking alters the dynamic relationship between blood pressure and cerebral blood flow. We hypothesised that acute and chronic smoking would result in a cerebral circulation that was less capable of buffering against dynamic fluctuations in blood pressure. Further, these changes would be accompanied by a reduction in baroreflex sensitivity, which is reduced after smoking (acute smoking. METHODS: We recruited 17 non-smokers and 15 habitual smokers (13 ± 5 pack years. Continuous measurements of mean cerebral blood flow velocity (transcranial Doppler ultrasound, blood pressure (finger photoplethysmography and heart rate enabled transfer function analysis of the dynamic relationship between pressure and flow (gain, normalised gain, phase and coherence and baroreflex sensitivity during supine rest before and after smoking a single cigarette (acute smoking. RESULTS: There were no between-group differences in gain, phase or coherence before acute smoking. However, both groups showed a reduction in gain and coherence, associated with a reduction in baroreflex sensitivity, and increase in phase after acute smoking. CONCLUSIONS: Contrary to our hypothesis, these findings suggest that in the face of a reduction in baroreflex sensitivity acute smoking may potentially improve the ability of the cerebral circulation to buffer against changes in blood pressure. However, chronic smoking did not alter the dynamic relationship between blood pressure and cerebral blood flow velocity. These results have implications on understanding mechanisms for attenuating stroke risk.

  2. Relationship of Early Spontaneous Type V Blood Pressure Fluctuation after Thrombolysis in Acute Cerebral Infarction Patients and the Prognosis

    OpenAIRE

    Lian Zuo; Ting Wan; Xiahong Xu; Feifeng Liu; Changsong Li; Ying Li; Yue Zhang; Jing Zhang; Huan Bao; Gang Li

    2016-01-01

    We examined the relationship between an early spontaneous type V blood pressure fluctuation and the post-thrombolysis prognosis of patients with acute cerebral infarction. Patients were admitted consecutively. All patients were categorized into the type V blood pressure fluctuation group or non-type V blood pressure group. Their blood pressure was monitored before thrombolysis and until 6 h after thrombolysis. Baseline data and clinical outcomes were compared. Of 170 patients, 43 (25.2%) had ...

  3. Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery

    OpenAIRE

    Jiang, Yuanliang; Peng, Wenjia; Teng, Zhongzhao; Gillard, Jonathan H.; Hong, Bo; Liu, Qi; Lu, Jianping

    2016-01-01

    The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to...

  4. MRI evidence for preserved regulation of intracranial pressure in patients with cerebral arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Meinel, Felix G.; Fischer, Judith; Pomschar, Andreas; Wöhrle, Natalie; Koerte, Inga K.; Steffinger, Denise [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377 Munich (Germany); Laubender, Rüdiger P. [Institute of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Muacevic, Alexander [European Cyberknife Center Munich, 81377 Munich (Germany); Reiser, Maximilian F. [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377 Munich (Germany); Alperin, Noam [Department of Radiology, Miller School of Medicine, University of Miami, Miami, FL 33136 (United States); Ertl-Wagner, Birgit, E-mail: birgit.ertl-wagner@med.uni-muenchen.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377 Munich (Germany)

    2014-08-15

    Purpose: The purpose of this study was to investigate intracranial pressure and associated hemo- and hydrodynamic parameters in patients with cerebral arteriovenous malformations AVMs. Methods: Thirty consecutive patients with arteriovenous malformations (median age 38.7 years, 27/30 previously treated with radiosurgery) and 30 age- and gender-matched healthy controls were investigated on a 3.0 T MR scanner. Nidus volume was quantified on dynamic MR angiography. Total arterial cerebral blood flow (tCBF), venous outflow as well as aqueductal and craniospinal stroke volumes were obtained using velocity-encoded cine-phase contrast MRI. Intracranial volume change during the cardiac cycle was calculated and intracranial pressure (ICP) was derived from systolic intracranial volume change (ICVC) and pulse pressure gradient. Results: TCBF was significantly higher in AVM patients as compared to healthy controls (median 799 vs. 692 mL/min, p = 0.007). There was a trend for venous flow to be increased in both the ipsilateral internal jugular vein (IJV, 282 vs. 225 mL/min, p = 0.16), and in the contralateral IJV (322 vs. 285 mL/min, p = 0.09), but not in secondary veins. There was no significant difference in median ICP between AVM patients and control subjects (6.9 vs. 8.6 mmHg, p = 0.30) and ICP did not correlate with nidus volume in AVM patients (ρ = −0.06, p = 0.74). There was a significant positive correlation between tCBF and craniospinal CSF stroke volume (ρ = 0.69, p = 0.02). Conclusions: The elevated cerebral blood flow in patients with AVMs is drained through an increased flow in IJVs but not secondary veins. ICP is maintained within ranges of normal and does not correlate with nidus volume.

  5. The influence of calculation method on estimates of cerebral critical closing pressure

    International Nuclear Information System (INIS)

    The critical closing pressure (CrCP) of cerebral circulation is normally estimated by extrapolation of instantaneous velocity–pressure curves. Different methods of estimation were analysed to assess their robustness and reproducibility in both static and dynamic applications. In ten healthy subjects (mean ± SD age 37.5 ± 9.2 years) continuous recordings of arterial blood pressure (BP, Finapres) and bilateral cerebral blood flow velocity (transcranial Doppler ultrasound, middle cerebral arteries) were obtained at rest. Each session consisted of three separate 5 min recordings. A total of four recording sessions for each subject took place over a 2 week period. A total of 117 recordings contained 34 014 cardiac cycles. For each cardiac cycle, CrCP and resistance-area product (RAP) were estimated using linear regression (LR), principal component analysis (PCA), first harmonic fitting (H1), 2-point systolic/diastolic values (2Ps) and 2-point mean/diastolic values (2Pm). LR and PCA were also applied using only the diastolic phase (LRd, PCAd). The mean values of CrCP and RAP for the entire 5 min recording ('static' condition) were not significantly different for LRd, PCAd, H1 and 2Pm, as opposed to the other methods. The same four methods provided the best results regarding the absence of negative values of CrCP and the coefficient of variation (CV) of the intra-subject standard error of the mean (SEM). On the other hand, 'dynamic' applications, such as the transfer function between mean BP and RAP (coherence and RAP step response) led to a different ranking of methods, but without significant differences in CV SEM coherence. For the CV of the RAP step response though, LRd and PCAd performed badly. These results suggest that H1 or 2Pm perform better than LR analysis and should be used for the estimation of CrCP and RAP for both static and dynamic applications

  6. Reduction in Cerebral Oxygenation After Prolonged Exercise in Hypoxia is Related to Changes in Blood Pressure.

    Science.gov (United States)

    Horiuchi, Masahiro; Dobashi, Shohei; Kiuchi, Masataka; Endo, Junko; Koyama, Katsuhiro; Subudhi, Andrew W

    2016-01-01

    We investigated the relation between blood pressure and cerebral oxygenation (COX) immediately after exercise in ten healthy males. Subjects completed an exercise and recovery protocol while breathing either 21% (normoxia) or 14.1% (hypoxia) O2 in a randomized order. Each exercise session included four sets of cycling (30 min/set, 15 min rest) at 50% of altitude-adjusted peak oxygen uptake, followed by 60 min of recovery. After exercise, mean arterial pressure (MAP; 87±1 vs. 84±1 mmHg, average values across the recovery period) and COX (68±1% vs. 58±1%) were lower in hypoxia compared to normoxia (Pblood pressure following exercise in hypoxia are (1) more pronounced than in normoxia, and (2) associated with reductions in COX. Together, these results suggest an impairment in cerebral autoregulation as COX followed changes in MAP more passively in hypoxia than in normoxia. These findings could help explain the increased risk for postexercise syncope at high altitude. PMID:26782200

  7. Impaired cerebral cortex development and blood pressure regulation in FGF-2-deficient mice.

    Science.gov (United States)

    Dono, R; Texido, G; Dussel, R; Ehmke, H; Zeller, R

    1998-08-01

    Fibroblast growth factor-2 (FGF-2) has been implicated in various signaling processes which control embryonic growth and differentiation, adult physiology and pathology. To analyze the in vivo functions of this signaling molecule, the FGF-2 gene was inactivated by homologous recombination in mouse embryonic stem cells. FGF-2-deficient mice are viable, but display cerebral cortex defects at birth. Bromodeoxyuridine pulse labeling of embryos showed that proliferation of neuronal progenitors is normal, whereas a fraction of them fail to colonize their target layers in the cerebral cortex. A corresponding reduction in parvalbumin-positive neurons is observed in adult cortical layers. Neuronal defects are not limited to the cerebral cortex, as ectopic parvalbumin-positive neurons are present in the hippocampal commissure and neuronal deficiencies are observed in the cervical spinal cord. Physiological studies showed that FGF-2-deficient adult mice are hypotensive. They respond normally to angiotensin II-induced hypertension, whereas neural regulation of blood pressure by the baroreceptor reflex is impaired. The present genetic study establishes that FGF-2 participates in controlling fates, migration and differentiation of neuronal cells, whereas it is not essential for their proliferation. The observed autonomic dysfunction in FGF-2-deficient adult mice uncovers more general roles in neural development and function. PMID:9687490

  8. Pressure passive cerebral blood flow and breakdown of the blood-brain barrier in experimental fetal asphyxia

    DEFF Research Database (Denmark)

    Lou, H C; Lassen, N A; Tweed, W A;

    1979-01-01

    mean arterial blood pressure in the fetuses by blood withdrawal or infusion in this state, CBF was measured at different perfusion pressures (mean arterial blood pressure (MABP) minus central venous pressure (CVP)). A passive flow/pressure relationship--loss of autoregulation--was found, with hyperemia...... reaching CBF values up to 6 times normal at normal MABP of about 60 to 70 mmHg, and severe ischemia reaching CBF values close to zero in large cortical areas at MABP of 30 mmHg. CVP remained essentially unchanged at 10--15 mmHg. The severe and prolonged asphyxia rendered the blood-brain barrier leaky to...

  9. CT perfusion in acute stroke

    International Nuclear Information System (INIS)

    Stroke is a heterogeneous syndrome caused by multiple mechanisms, all of which result in disruption of normal cerebral blood flow and thereby cause cerebral dysfunction. Its early diagnosis is important as its treatment is dependent on the time elapsed since ictus. Delay in diagnosis and treatment translates into increase neuronal loss and thereby increased morbidity. CT scan, and in particular perfusion CT, has helped greatly in the early diagnosis of stroke. This article is an endeavor to explain the pathophysiology of cerebral ischemia and the role of CT perfusion in detecting it

  10. Effects of Ginkgo biloba on cerebral blood flow assessed by quantitative MR perfusion imaging: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Mashayekh, Ameneh; Pham, Dzung L.; Yousem, David M.; Dizon, Mercedes; Barker, Peter B.; Lin, Doris D.M. [Johns Hopkins University School of Medicine, Department of Radiology, Division of Neuroradiology, Baltimore, MD (United States)

    2011-03-15

    Extract of Ginkgo biloba (EGb), a dietary supplement used for a number of conditions including dementia, has been suggested to increase cerebral blood flow (CBF). The purpose of this study was to determine if changes in CBF could be detected by dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) in elderly human subjects taking EGb. DSC-MRI was performed in nine healthy men (mean age 61 {+-} 10 years) before and after 4 weeks of 60 mg EGb taken twice daily. One subject underwent six consecutive scans to evaluate intrasubject reproducibility. CBF values were computed before and after EGb, and analyzed at three different levels of spatial resolution, using voxel-based statistical parametric mapping (SPM), and regions of interest in different lobes, and all regions combined. Normalized intrasubject CBF (nCBF) measurements had a standard deviation of 7% and 4% in gray and white matter (WM) regions, respectively. SPM using an uncorrected, voxel-level threshold of P {<=} 0.001 showed a small CBF increase in the left parietal-occipital region. CBF in individual lobar regions did not show any significant change post-EGb, but all regions combined showed a significant increase of non-normalized CBF after EGb (15% in white and 13% in gray matter, respectively, P {<=} 0.0001). nCBF measured by DSC-MRI has good intrasubject reproducibility. In this small cohort of normal elderly individuals, a mild increase in CBF is found in the left parietal-occipital WM after EGb, as well as a small but statistically significant increase in global CBF. (orig.)

  11. Effects of Ginkgo biloba on cerebral blood flow assessed by quantitative MR perfusion imaging: a pilot study

    International Nuclear Information System (INIS)

    Extract of Ginkgo biloba (EGb), a dietary supplement used for a number of conditions including dementia, has been suggested to increase cerebral blood flow (CBF). The purpose of this study was to determine if changes in CBF could be detected by dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) in elderly human subjects taking EGb. DSC-MRI was performed in nine healthy men (mean age 61 ± 10 years) before and after 4 weeks of 60 mg EGb taken twice daily. One subject underwent six consecutive scans to evaluate intrasubject reproducibility. CBF values were computed before and after EGb, and analyzed at three different levels of spatial resolution, using voxel-based statistical parametric mapping (SPM), and regions of interest in different lobes, and all regions combined. Normalized intrasubject CBF (nCBF) measurements had a standard deviation of 7% and 4% in gray and white matter (WM) regions, respectively. SPM using an uncorrected, voxel-level threshold of P ≤ 0.001 showed a small CBF increase in the left parietal-occipital region. CBF in individual lobar regions did not show any significant change post-EGb, but all regions combined showed a significant increase of non-normalized CBF after EGb (15% in white and 13% in gray matter, respectively, P ≤ 0.0001). nCBF measured by DSC-MRI has good intrasubject reproducibility. In this small cohort of normal elderly individuals, a mild increase in CBF is found in the left parietal-occipital WM after EGb, as well as a small but statistically significant increase in global CBF. (orig.)

  12. Assessment of Cerebral Hemodynamic Changes in Pediatric Patients with Moyamoya Disease Using Probabilistic Maps on Analysis of Basal/Acetazolamide Stress Brain Perfusion SPECT

    International Nuclear Information System (INIS)

    To evaluate the hemodynamic changes and the predictive factors of the clinical outcome in pediatric patients with moyamoya disease, we analyzed pre/post basal/acetazolamide stress brain perfusion SPECT with automated volume of interest (VOIs) method. Total fifty six (M:F=33:24, age 6.7±3.2 years) pediatric patients with moyamoya disease, who underwent basal/acetazolamide stress brain perfusion SPECT within 6 before and after revascularization surgery (encephalo-duro-arterio-synangiosis (EDAS) with frontal encephalo-galeo-synangiosis (EGS) and EDAS only followed on contralateral hemisphere), and followed-up more than 6 months after post-operative SPECT, were included. A mean follow-up period after post-operative SPECT was 33±21 months. Each patient's SPECT image was spatially normalized to Korean template with the SPM2. For the regional count normalization, the count of pons was used as a reference region. The basal/acetazolamide-stressed cerebral blood flow (CBF), the cerebral vascular reserve index (CVRI), and the extent of area with significantly decreased basal/acetazolamide- stressed rCBF than age-matched normal control were evaluated on both medial frontal, frontal, parietal, occipital lobes, and whole brain in each patient's images. The post-operative clinical outcome was assigned as good, poor according to the presence of transient ischemic attacks and/or fixed neurological deficits by pediatric neurosurgeon. In a paired t-test, basal/acetazolamide-stressed rCBF and the CVRI were significantly improved after revascularization (p<0.05). The significant difference in the pre-operative basal/acetazolamide-stressed rCBF and the CVRI between the hemispheres where EDAS with frontal EGS was performed and their contralateral counterparts where EDAS only was done disappeared after operation (p<0.05). In an independent student t-test, the pre-operative basal rCBF in the medial frontal gyrus, the post-operative CVRI in the frontal lobe and the parietal lobe of the

  13. Cerebral perfusion (HMPAO-SPECT) in patients with depression with cognitive impairment versus those with mild cognitive impairment and dementia of Alzheimer's type: a semiquantitative and automated evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Staffen, W.; Bergmann, J.; Schoenauer, U.; Kronbichler, M.; Golaszewski, S.; Ladurner, G. [Paracelsus Medical University, Christian-Doppler-Clinic, Department of Neurology, and Center of Cognitive Research Salzburg, Salzburg (Austria); Zauner, H. [Rehabilitation Center of the Pensionsversicherungsanstalt, Grossgmain (Austria)

    2009-05-15

    Comparative evaluation of regional brain perfusion measured by HMPAO-SPECT of patients with mild cognitive impairment (MCI), dementia of Alzheimer's type (DAT) and depression with cognitive impairment (DCI). A total of 736 patients were investigated because of suspected cognitive dysfunction. After exclusion of patients with other forms of dementia than DAT or relevant accompanying disorders, SPECT data from 149 MCI, 131 DAT and 127 DCI patients, and 123 controls without any cognitive impairment, were analysed. Relative cerebral blood flow of 34 anatomical regions was assessed with automated analysis software (BRASS). Calculation of global forebrain perfusion discriminated demented from nondemented patients. Compared to controls DCI patients showed hypoperfusion of the thalamus, lentiform nucleus and medial temporal cortex. MCI patients differed significantly from controls concerning perfusion in both hemispheric temporal and parietal areas, and in the (right hemispheric) posterior part of the cingulate gyrus. MCI and DCI patients differed in the parietal, temporal superior and right hemispheric cingulate gyrus posterior cortices. Global forebrain and regional perfusion was more extensively reduced in DAT patients and discriminated them from controls, and MCI and DCI patients. Frontal perfusion disturbance was only present in DAT patients. Automated analysis of HMPAO-SPECT data from MCI patients showed significant perfusion deficits in regions also involved in DAT patients, but ROC analysis demonstrated only moderate sensitivity and specificity for differentiating DAT patients from controls and DCI patients. Frontal hypoperfusion seems to correspond with conversion from MCI to DAT. Finally, the results in DCI patients again raise the question of depression as an early symptom of neurodegeneration. (orig.)

  14. Comparison of EMG Biofeedback and Johnstone Pressure Splints in Children with Hemiplegic Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Ali Kitiş

    2010-10-01

    Full Text Available Objective: This study was carried out to compare Johnstone pressure splints and electromyographic (EMG biofeedback in addition to neurodevelopmental therapy on activities of daily living, sensory perception and motor integration functions, functional hand activities, and muscle tone in children with hemiplegic cerebral palsy (CP. Materials and Methods: Thirty-eight children with spastic hemiplegic cerebral palsy, whose motor development levels were similar, were included in this study and were divided into two groups. In addition to Bobath’s neurodevelopmental therapy, Group I was treated with pressure splints for the upper extremity and Group II-with EMG biofeedback training, also applied to the upper extremity, three times a week for three months. In the biofeedback group the session length was 20 minutes and in the Johnstone group, it was 50 minutes in total, with and without splinting. Patients were evaluated for muscle tone, activities of daily living, sensory perception and motor integration functions, and functional hand activities before and after therapy, and on the third and sixth months following therapy. Results: At the third and sixth months after treatment, significant improvement was found in muscle tone, activities of daily living, sensory perception and motor integration functions, and functional hand activities (p<0.05. Moreover, the findings in Group I were more significant than those in Group II (p<0.001. Conclusion: These results show that both treatment methods are helpful to Bobath approach in cerebral palsy rehabilitation. However, EMG biofeedback treatment is more effective due to the fact that it encourages the child’s active participation. Turk J Phys Med Rehab 2010;56:116-23.

  15. Redox signaling via oxidative inactivation of PTEN modulates pressure-dependent myogenic tone in rat middle cerebral arteries.

    Directory of Open Access Journals (Sweden)

    Debebe Gebremedhin

    Full Text Available The present study examined the level of generation of reactive oxygen species (ROS and roles of inactivation of the phosphatase PTEN and the PI3K/Akt signaling pathway in response to an increase in intramural pressure-induced myogenic cerebral arterial constriction. Step increases in intraluminal pressure of cannulated cerebral arteries induced myogenic constriction and concomitant formation of superoxide (O2 (.- and its dismutation product hydrogen peroxide (H2O2 as determined by fluorescent HPLC analysis, microscopic analysis of intensity of dihydroethidium fluorescence and attenuation of pressure-induced myogenic constriction by pretreatment with the ROS scavenger 4,hydroxyl-2,2,6,6-tetramethylpiperidine1-oxyl (tempol or Mito-tempol or MitoQ in the presence or absence of PEG-catalase. An increase in intraluminal pressure induced oxidation of PTEN and activation of Akt. Pharmacological inhibition of endogenous PTEN activity potentiated pressure-dependent myogenic constriction and caused a reduction in NPo of a 238 pS arterial KCa channel current and an increase in [Ca(2+]i level in freshly isolated cerebral arterial muscle cells (CAMCs, responses that were attenuated by Inhibition of the PI3K/Akt pathway. These findings demonstrate an increase in intraluminal pressure induced increase in ROS production triggered redox-sensitive signaling mechanism emanating from the cross-talk between oxidative inactivation of PTEN and activation of the PI3K/Akt signaling pathway that involves in the regulation of pressure-dependent myogenic cerebral arterial constriction.

  16. Random perturbations of arterial blood pressure for the assessment of dynamic cerebral autoregulation

    International Nuclear Information System (INIS)

    The assessment of cerebral autoregulation (CA) relies mostly on methods that modulate arterial blood pressure (ABP). Despite advances, the gold standard of assessment remains elusive and clinical practicality is limited. We investigate a novel approach of assessing CA, consisting of the intermittent application of thigh cuffs using square wave sequences. Our aim was to increase ABP variability whilst minimizing volunteer discomfort, thus improving assessment acceptability. Two random square wave sequences and two maximum pressure settings (80 and 150 mmHg) were used, corresponding to four manoeuvres that were conducted in random order after a baseline recording. The intermittent application of thigh cuffs resulted in an amplitude dependent increase in ABP (p = 0.001) and cerebral blood flow velocity (CBFV) variability (p = 0.026) compared to baseline. No statistically significant differences in mean heart rate or heart rate variability were observed (p = 0.108 and p = 0.350, respectively), suggesting that no significant sympathetic response was elicited. No significant differences in the CBFV step response were observed, suggesting no distortion of autoregulatory parameters resulted from the use of thigh cuffs. We conclude that pseudorandom binary sequences are an effective and safe alternative for increasing ABP variability. This new approach shows great promise as a tool for the robust assessment of CA. (paper)

  17. Comparison of the effects of bimatoprost and a fixed combination of latanoprost and timolol on 24-hour blood and ocular perfusion pressures: the results of a randomized trial

    OpenAIRE

    Rossetti, Luca; Sacchi, Matteo; Karabatsas, Costas H; Topouzis, Fotis; Vetrugno, Michele; Centofanti, Marco; Boehm, Andreas; Vorwerk, Christian; Goldblum, David; Fogagnolo, Paolo

    2015-01-01

    Background To compare the effect of bimatoprost and the fixed combination latanoprost-timolol (LTFC) on 24-hour systolic (SBP) and diastolic (DBP) blood pressure and on 24-hour ocular perfusion pressure (OPP). Methods 200 patients with glaucoma or ocular hypertension, controlled on the unfixed combination of latanoprost and timolol or eligible for dual therapy being not being fully controlled on monotherapy were enrolled in a randomized, double-masked, placebo-controlled, multicentre clinical...

  18. Influence of Exercise Modality on Cerebral-Ocular Hemodynamics and Pressures

    Science.gov (United States)

    Scott, J.; Martin, D.; Crowell, B.; Goetchius, E.; Seponski, C.; Gonzales, R.; Matz, T.; Ploutz-Snyder, R.; Stenger, M.; Ploutz-Snyder, L.

    2016-01-01

    Background: Moderate and high intensity aerobic or resistance exercise has clearly identified benefits for cardiac, muscle, and bone health. However, the impact of such exercise - either as a mitigating or an exacerbating factor - on the development of the visual impairment and intracranial pressure syndrome (VIIP) is unknown. Accordingly, our aim was to characterize the effect of an acute bout of resistance (RE), moderate-intensity continuous (CE), and high-intensity interval exercise (IE) during a cephalad fluid shift on cerebral-ocular hemodynamics and pressures. Methods: 10 male subjects (36 plus or minus 9 years) completed 4 testing days in a 15 degree head-down tilt (HDT): (1) assessment of maximum volume of O (sub 2), (2) RE session (4 sets of 12 repetition maximum leg press exercise), (3) CE session (30 minutes of cycling at 60 percent maximum volume of O (sub 2)), and (4) IE session (4 by 4-minute intervals of exercise at 85 percent maximum volume of O (sub 2) with 3-minute active rest periods). During each session, blood flow (Vivid-e, GE Healthcare) in extracranial arteries (common carotid artery, CCA; internal carotid artery, ICA; external carotid artery, ECA and vertebral artery, VA), and mean blood flow velocity in middle cerebral artery (MCA), internal jugular pressure (IJP; VeinPress), and intraocular pressure (IOP; Icare PRO) were measured at rest, at the end of each resistance or interval set, and every 5 minutes during continuous exercise. Translaminar pressure gradient (TLPG) was estimated by subtracting IJP from IOP. Results: There were no differences across days in pre-exercise resting blood flows or pressures. IOP decreased slightly from HDT rest (20.2 plus or minus 2.3 millimeters of mercury) to exercise (RE: 19.2 plus or minus 2.8 millimeters of mercury; CE: 18.9 plus or minus 3.2 millimeters of mercury; IE: 20.1 plus or minus 2.8 millimeters of mercury), while IJP decreased during CE (31.6 plus or minus 9.5 millimeters of mercury) and RE

  19. Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging.

    Science.gov (United States)

    Smirl, Jonathan D; Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N

    2016-03-01

    The cerebral pressure-flow relationship can be quantified as a high-pass filter, where slow oscillations are buffered (TFA) findings (altered phase or intact gain). This study aimed to determine whether these previous findings accurately represent this relationship. Both younger (20-30 yr; n = 10) and older (62-72 yr; n = 9) adults were examined. To enhance the signal-to-noise ratio, large oscillations in blood pressure (via oscillatory lower body negative pressure; OLBNP) were induced during steady-state moderate intensity supine exercise (∼45-50% of heart rate reserve). Beat-to-beat blood pressure, cerebral blood velocity, and end-tidal Pco2 were monitored. Very low frequency (0.02-0.07 Hz) and low frequency (0.07-0.20 Hz) range spontaneous data were quantified. Driven OLBNP point estimates were sampled at 0.05 and 0.10 Hz. The OLBNP maneuvers augmented coherence to >0.97 at 0.05 Hz and >0.98 at 0.10 Hz in both age groups. The OLBNP protocol conclusively revealed the cerebrovascular system functions as a high-pass filter during exercise throughout aging. It was also discovered that the older adults had elevations (+71%) in normalized gain (+0.46 ± 0.36%/%: 0.05 Hz) and reductions (-34%) in phase (-0.24 ± 0.22 radian: 0.10 Hz). There were also age-related phase differences between resting and exercise conditions. It is speculated that these age-related changes in the TFA metrics are mediated by alterations in vasoactive factors, sympathetic tone, or the mechanical buffering of the compliance vessels. PMID:26586907

  20. High-Pressure Transvenous Perfusion of the Upper Extremity in Human Muscular Dystrophy: A Safety Study with 0.9% Saline.

    Science.gov (United States)

    Fan, Zheng; Kocis, Keith; Valley, Robert; Howard, James F; Chopra, Manisha; Chen, Yasheng; An, Hongyu; Lin, Weili; Muenzer, Joseph; Powers, William

    2015-09-01

    We evaluated safety and feasibility of high-pressure transvenous limb perfusion in an upper extremity of adult patients with muscular dystrophy, after completing a similar study in a lower extremity. A dose escalation study of single-limb perfusion with 0.9% saline was carried out in nine adults with muscular dystrophies under intravenous analgesia. Our study demonstrates that it is feasible and definitely safe to perform high-pressure transvenous perfusion with 0.9% saline up to 35% of limb volume in the upper extremities of young adults with muscular dystrophy. Perfusion at 40% limb volume is associated with short-lived physiological changes in peripheral nerves without clinical correlates in one subject. This study provides the basis for a phase 1/2 clinical trial using pressurized transvenous delivery into upper limbs of nonambulatory patients with Duchenne muscular dystrophy. Furthermore, our results are applicable to other conditions such as limb girdle muscular dystrophy as a method for delivering regional macromolecular therapeutics in high dose to skeletal muscles of the upper extremity. PMID:25953425

  1. Exploring the Influence of Simulated Microgravity Environment on Human Cerebral Perfusion Based on ASL Technology%基于ASL技术探讨模拟微重力环境对人脑灌注的影响

    Institute of Scientific and Technical Information of China (English)

    顾正章; 邢伟; 金真; 李科

    2014-01-01

    目的:基于动脉自旋标记(arterial spin labeling, ASL)方法,探讨模拟微重力环境对人脑灌注的影响。材料与方法对14名男性志愿者进行30天的-6°头低位卧床来模拟微重力环境。使用3.0T磁共振仪器采集模拟微重力实验前后脑灌注及高分辨率解剖成像图像数据,用SPM8软件分析比较模拟微重力前后志愿者的脑灌注变化。结果在经历30天模拟微重力实验后,14名志愿者的组分析结果显示为两侧大脑半球为非对称性灌注增加和减少,灌注增加的脑区为左侧后扣带回、右侧颞中回及右侧岛叶,差异具有统计学显著性(p<0.001),左侧后扣带回为灌注增加最显著脑区,其次是右侧颞中回和右侧岛叶。同时左侧颞上回脑灌注显著减少,差异具有统计学显著性(p<0.001)。结论运用ASL技术能够探明模拟微重力环境下常规影像学检查无法发现的灌注变化脑区,为临床和科研工作提供更多信息。%Objective To investigate the effect of simulated microgravity on human cerebral perfusion by using ASL. MaterialandMethods Fourteen healthy male volunteers underwent -6°head-down bed rest(HDBR) for 30d to simulate microgravity. High-resolution brain anatomical imaging data and cerebral perfusion images were collected by using 3.0T MR before and after HDBR. Using analysis software package SPM8, the pre-and post HDBR image data were calculated, analyzed and compared. Results After HDBR, group analysis of fourteen volunteers showed asymmetric perfusion increase and reduce of the hemispheres.The cerebral perfusion was significantly increased in the left posterior cingulate cortex, right middle temporal gyrus and right insula(p<0.001). Among them, left posterior cingulate cortex showed the most remarkable increase of cerebral perfusion. While the cerebral perfusion was decreased in left superior temporal gyrus(p<0.001). Conclusion Brain areas of perfusion changes in

  2. Outflow facility efficacy of five drugs in enucleated porcine eyes by a method of constant-pressure perfusion.

    Science.gov (United States)

    Li, Ning; Shi, Hui-Min; Cong, Lin; Lu, Zhao-Zeng; Ye, Wen; Zhang, Yu-Yan

    2015-01-01

    This study aimed to characterize a technique that assesses the outflow facility (C) efficacy of five kinds of IOP-lowering drugs commonly used clinically in enucleated porcine Eyes. Eyes were perfused at 15 mmHg with GPBS first to establish the baseline outflow facility (C0). Then the anterior chamber contents were exchanged for GPBS with corresponding concentration eye drops (4.9×10(3) nM Brimonidine, 41.1 nM Latanoprost, 3.4×10(3) nM Levobunolol, 3.0×10(3) nM Brinzolamide, 8.3×10(3) nM Pilocarpine) in five groups (n = 6 each), while 6 eyes received GPBS alone as control. The mean stable facility obtained after drug administration (C1) was continuously recorded. The changes between C0 and C1 (ΔC = C1-C0) were analyzed. Finally, for drugs among the five experiment groups with statistical significance, the concentration was reduced 3 times, otherwise the drugs' concentration was increased to 10 times to confirm its effectiveness further using the same methods (n = 6 each). We found that the average baseline outflow facility was 0.24±0.01 μl·min(-1)·mmHg(-1). C increased significantly in Brimonidine and Latanoprost groups, even the concentration of Brimonidine and Latanoprost was decreased 3 times (P Brinzolamide, Pilocarpine and control group (P > 0.05), but when drugs' concentration was increased to 10 times, the C value of Pilocarpine decreased significantly (P = 0.04). No significant washout effects in porcine eyes were observed. To conclude, outflow facility efficacy of five drugs in enucleated porcine eyes may provide a reference for clinical medicine. A constant-pressure perfusion technique should be useful to evaluate effect of pharmacologic agents or surgical manipulations on aqueous humor dynamics. PMID:26221257

  3. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    AnthonyRichardBain

    2014-03-01

    Full Text Available Hyperthermia is associated with marked reductions in cerebral blood flow (CBF. Increased distribution of cardiac output to the periphery, increases in alveolar ventilation and resultant hypocapnia each contribute to the fall in CBF during passive hyperthermia; however, their relative contribution remains a point of contention, and probably depends on the experimental condition (e.g. posture and degree of hyperthermia. The hyperthermia-induced hyperventilatory response reduces arterial CO2 pressure (PaCO2 causing cerebral vasoconstriction and subsequent reductions in flow. During supine passive hyperthermia, the majority of recent data indicate that reductions in PaCO2 may be the primary, if not sole, culprit for reduced CBF. On the other hand, during more dynamic conditions (e.g. hemorrhage or orthostatic challenges, an inability to appropriately decrease peripheral vascular conductance presents a condition whereby adequate cerebral perfusion pressure may be compromised secondary to reductions in systemic blood pressure. Although studies have reported maintenance of pre-frontal cortex oxygenation (assessed by near-infrared spectroscopy during exercise and severe heat stress, the influence of cutaneous blood flow is known to contaminate this measure. This review discusses the governing mechanisms associated with changes in CBF and oxygenation during moderate to severe (i.e. 1.0°C to 2.0°C increase in body core temperature levels of hyperthermia. Future research directions are provided.

  4. Multimodal pressure-flow method to assess dynamics of cerebral autoregulation in stroke and hypertension

    Directory of Open Access Journals (Sweden)

    Lipsitz Lewis A

    2004-10-01

    Full Text Available Abstract Background This study evaluated the effects of stroke on regulation of cerebral blood flow in response to fluctuations in systemic blood pressure (BP. The autoregulatory dynamics are difficult to assess because of the nonstationarity and nonlinearity of the component signals. Methods We studied 15 normotensive, 20 hypertensive and 15 minor stroke subjects (48.0 ± 1.3 years. BP and blood flow velocities (BFV from middle cerebral arteries (MCA were measured during the Valsalva maneuver (VM using transcranial Doppler ultrasound. Results A new technique, multimodal pressure-flow analysis (MMPF, was implemented to analyze these short, nonstationary signals. MMPF analysis decomposes complex BP and BFV signals into multiple empirical modes, representing their instantaneous frequency-amplitude modulation. The empirical mode corresponding to the VM BP profile was used to construct the continuous phase diagram and to identify the minimum and maximum values from the residual BP (BPR and BFV (BFVR signals. The BP-BFV phase shift was calculated as the difference between the phase corresponding to the BPR and BFVR minimum (maximum values. BP-BFV phase shifts were significantly different between groups. In the normotensive group, the BFVR minimum and maximum preceded the BPR minimum and maximum, respectively, leading to large positive values of BP-BFV shifts. Conclusion In the stroke and hypertensive groups, the resulting BP-BFV phase shift was significantly smaller compared to the normotensive group. A standard autoregulation index did not differentiate the groups. The MMPF method enables evaluation of autoregulatory dynamics based on instantaneous BP-BFV phase analysis. Regulation of BP-BFV dynamics is altered with hypertension and after stroke, rendering blood flow dependent on blood pressure.

  5. Discussion on the treatment of cerebral ischemia-reperfusion injuries following intra-arterial thrombolysis

    International Nuclear Information System (INIS)

    Objective: To investigate the therapeutic method of cerebral ischemia-reperfusion injuries occurred after arterial thrombolytic therapy for acute cerebral infarction. Methods: Thirty-five patients, encountered in authors' Department since Oct. 2005, with cerebral ischemia-reperfusion injuries, which occurred after thrombolytic therapy by using arterial perfusion of urokinase for acute cerebral infarction, were enrolled in this study. The clinical data were retrospectively analyzed. Results: After the thrombolytic therapy, completer or partial recanalization of the occluded cerebral arteries was obtained in 33 cases, while secondary cerebral hemorrhage occurred in 13 cases, of whom cerebral parenchyma bleeding was seen in 2 and hemorrhagic infarction in 11. Different degrees of cerebral edema were found in all 33 cases. Among them significant shift of the midline structures was detected in 18 (54.5%), which was manifested clinically as the worsening of disturbance of consciousness. Strict control of blood pressure, prompt adjustment of dehydration medication, strengthening the cerebral protection measures, cerebral decompression by fenestration, etc. were carried out. All the patients took a turn for the better and were out of danger with remarkable improvement of neurological functions except one patient who died from massive intracerebral hemorrhage. Conclusion: Usually, different degrees of reperfusion injuries will develop after thrombolytic therapy for cerebral arterial infarction. Strictly controlling blood pressure, promptly adjusting dehydration medication and strengthening cerebral protection are the keys to reduce the severity of cerebral reperfusion injuries. (authors)

  6. 脑梗死前期磁共振脑灌注成像20例分析%Correlation analysis of magnetic resonance perfusion imaging and its stages of regional cerebral hypoperfusion in pre-infarction period

    Institute of Scientific and Technical Information of China (English)

    曾裕镜

    2008-01-01

    目的 探讨脑梗死前期MR脑灌注成像的表现和分期临床应用价值.方法 采用MR脑灌注成像对20例脑血管病患者的197层脑灌注图像和对照组20例非脑血管病患者的197层脑灌注成像进行分析,计算每层图像的患/健侧比值,并与对照组的正常比值及其范围比较.以非参数统计方法、多元方差分析和两两比较分析病例组和对照组脑灌注血流动力学参数及其分期.结果 病例组和对照组的4个血流动力学参数差异均有统计学意义(P<0.01).TTP(time to peak)和MTT(mean transit time)与发病的相关系数较高,分别为0.482和0.471,rCBV(regional cerebral blood volume)和rCBF(regional cerebral blood flow)较低,且为负值.脑梗死前期分期特征为:Ⅰ期一型TTP稍有延长,Ⅰ期二型MTT显著延长,Ⅱ期一型rCBF明显下降,Ⅱ期二型rCBV下降.结论 MR脑灌注成像可提供脑梗死前期的血流动力学参数变化的信息,并可以对其参数变化进行分期.%Objective To explore clinical value of application to magnetic resonance(MR) perfusion imaging and stages of regional cerebral hypoperfusion in preinfarction period and improve the diagnosis level for pre-infarction period,and prevent or decrease the incidence of cerebral infarction. Methods 20 cases of cerebral ischemia in case group and 20 cases of non-cerebral ischemia in control group were performed with dynamic perfusion. 197 MR images of case group were compared with 197 images of control group,calculating the ratios of illness side to normal for every image at hypoperfusion areas in the regional cerebral isehemia and referring and comparing their range provided by control group with methods of nonparametrie statistics and multivariate analysis of variance and multiple comparison. Results Four parameters of blood flow dynamics between two groups showed a significant difference (P<0.01). Correlation coefficients between time to peak(TTP) and time to peak(MTT) and incidence

  7. Early effects of combretastatin-A4 disodium phosphate on tumor perfusion and interstitial fluid pressure

    DEFF Research Database (Denmark)

    Ley, C.D.; Horsman, Michael Robert; Kristjansen, P.E.G.

    2007-01-01

    the tumor vasculature. It has been proposed that increased permeability causes a transient increase in interstitial fluid pressure (IFP), which in turn could collapse intratumoral blood vessels. We examined the immediate effects of CA4DP on tumor IFP in C3H mammary carcinoma. Mice were treated with...

  8. Comparison of Intraocular Pressure, Blood Pressure, Ocular Perfusion Pressure and Blood Flow Fluctuations During Dorzolamide Versus Timolol Add-On Therapy in Prostaglandin Analogue Treated Glaucoma Subjects

    Directory of Open Access Journals (Sweden)

    Ruta Barsauskaite

    2012-03-01

    Full Text Available Objective: To compare the effects of dorzolamide and timolol add-on therapy in open-angle glaucoma (OAG patients previously treated with prostaglandin analogue (Pg, by evaluating fluctuations in the intraocular (IOP, blood (BP, ocular perfusion pressures (OPP and retrobulbar blood flow (RBF parameters. Methods: 35 OAG patients (35 eyes, 31 women (88.6% age 63.3 (8.9 years were evaluated in a 3 month randomized, cross-over, single-masked study. During the experiments BP, heart rate, IOP and OPP were assessed 4 times per day (8–12–16–20 h. RBF was measured twice per day (8–20 h using Color Doppler imaging in the ophthalmic (OA, central retinal (CRA, nasal (nSPCA and temporal (tSPCA posterior ciliary arteries. In each vessel, peak systolic velocity (PSV and end-diastolic velocity (EDV were assessed and vascular resistance (RI calculated. Results: Both add-on therapies lowered IOP in a statistically significant manner from 15.7 ± 2.4 mmHg at latanoprost baseline to 14.9 ± 2.2 mmHg using dorzolamide (p < 0.001 and 14.2 ± 1.9 mmHg using timolol (p < 0.001. The IOP lowering effect was statistically significant at 20 h, favoring timolol as compared to dorzolamide (1.4 ± 2.4 vs. 0.2 ± 2.1 mmHg, (p < 0.05. Dorzolamide add-on therapy showed smaller IOP (2.0 ± 1.4, SPP (13.3 ± 7.9, systolic BP (13.5 ± 8.7 and diastolic BP (8.4 ± 5.4 fluctuations as compared to both latanoprost baseline or timolol add-on therapies. Higher difference between morning and evening BP was correlated to decreased evening CRA EDV in the timolol group (c = −0.41; p = 0.01. With increased MAP in the morning or evening hours, we found increased evening OA RI in timolol add-on group (c = 0.400, p = 0.02; c = 0.513, p = 0.002 accordingly. Higher MAP fluctuations were related to impaired RBF parameters during evening hours-decreased CRA EDV (c = −0.408; p = 0.01, increased CRA RI (c = 0.576; p < 0.001 and tSPCA RI (c = 0.356; p = 0.04 in the dorzolamide group and

  9. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result of artefacts in methods of measurement, such as the use of non-invasive measurements of BP in the finger. In 27 subjects (61 ± 11 years old) undergoing coronary artery angioplasty, BP was continuously recorded at rest with the Finapres device and in the ascending aorta (Millar catheter, BPAO), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO2. Dynamic CA was expressed by the autoregulation index (ARI), ranging from 0 (absence of CA) to 9 (best CA). Time-varying, continuous estimates of ARI (ARI(t)) were obtained with an autoregressive moving-average (ARMA) model applied to a 60 s sliding data window. No significant differences were observed in the accuracy and precision of ARI(t) between estimates derived from the Finapres and BPAO. Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BPAO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BPAO (right MCA r = 0.70 ± 0.22; left MCA r = 0.74 ± 0.22). Surrogate data showed that ARI(t) was highly sensitive to the presence of noise in the CBFV signal, with both the bias and dispersion of estimates increasing for lower values of ARI(t). This effect could explain the sudden drops of ARI(t) to zero as reported previously. Simulated sudden changes in ARI(t) can be detected by the Finapres, but the bias and variability of estimates also increase for lower values of ARI. In summary, the Finapres does not distort time-varying estimates of dynamic CA obtained with a sliding window combined with an ARMA model, but

  10. Dependency of cerebral blood flow upon mean arterial pressure in patients with acute bacterial meningitis

    DEFF Research Database (Denmark)

    Møller, Kirsten; Larsen, Fin Stolze; Qvist, Jesper;

    2000-01-01

    Diseases, Copenhagen University Hospital, Denmark. PATIENTS: Sixteen adult patients with acute bacterial meningitis. INTERVENTION: Infusion of norepinephrine to increase MAP. MEASUREMENTS: During a rise in MAP induced by norepinephrine infusion, we measured relative changes in CBF by transcranial Doppler......OBJECTIVE: Patients with acute bacterial meningitis are often treated with sympathomimetics to maintain an adequate mean arterial pressure (MAP). We studied the influence of such therapy on cerebral blood flow (CBF). DESIGN: Prospective physiologic trial. SETTING: The Department of Infectious....... Autoregulation was classified as impaired if Vmean increased by >10% per 30 mm Hg increase in MAP and if no lower limit of autoregulation was identified by the computer program; otherwise, autoregulation was classified as preserved. MAIN RESULTS: Initially, Vmean increased from a median value of 46 cm/sec (range...

  11. A simple model of cerebral blood flow dependence on arterial blood pressure

    CERN Document Server

    Gersten, Alexander

    2011-01-01

    It is shown that the dependence of the cerebral blood flow (CBF) on mean arterial blood pressure (MABP) can be described with a simple model having the following assumptions. Below certain MABP (denoted as MABP1) there are no autoregulatory or feedback mechanisms influencing CBF. Between MABP1 and MABP2 (MABP at which breakthrough accurs) there is a linear (on MABP) dependent feedback with a sloap depending very much on the individual considered. The classical autoregulation model with a plateau in between MABP1 and MABP2 is a particular case of this model. The model describes well the experiments performed on dogs (Harper 1966), for which the individual feedback sloap parameter varied to great extent, indicating the importance of mesurments on individuals against averaged mesurments (or measurments on diffent individuals) which superficially support the classical autoregulation. New effect of decreased CBF, while increasing MABP, was observed.

  12. Phase Synchronization of Pressure-Flow Fluctuations: A measure of cerebral autoregulation dynamics

    CERN Document Server

    Chen, Z; Ivanov, P C; Novák, V; Stanley, H E

    2006-01-01

    We employ a synchronization method to investigate the relationship between the blood flow velocities (BFV) in the middle cerebral arteries (MCA) and beat-to-beat blood pressure (BP) recorded from a finger in healthy and post-stroke subjects during four different physiologic conditions: supine, head-up tilt, hyperventilation and CO$_2$ rebreathing in upright position. To evaluate whether instantaneous BP changes are synchronized with changes in the BFV, we compare dynamical patterns in the instantaneous phases of these signals, obtained from the Hilbert transform, as a function of time. We find that in post-stroke subjects the instantaneous phase increments of BP and BFV exhibit well pronounced patterns that remain stable in time for all four physiologic conditions, while in healthy subjects these patterns are different, less pronounced and more variable. Further, we show that the instantaneous phase increments of BP and BFV are cross-correlated even within a single heartbeat cycle. The maximum correlation str...

  13. Effects of special brain area regional cerebral blood flow abnormal perfusion on learning and memory function and its molecular mechanism in rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    s To study the effect of special brain area regional cerebral blood flow (rCBF) abnormal perfusion on learning and memory function and its molecular mechanism,64 adult male healthy Spragne-Dawley (SD) rats were randomly divided into two groups,the false operation group (control group) and the operation group (model group).After surgical operation,the operation group undertook bilateral common carotid artery permanent ligation,while the other group did not.Learning and memory function were measured by Y-maze at 4 h,8 h,24 h and 3 d after surgical operation,respectively.The rCBF of the right frontal lobe and hippocampus was also detected by the PerifluxPF model laser Doppler flowmetry,and the expressions of c-fos or c-jun or Bcl-2 and Bax were also measured by immune histochemistry S-P method accordingly.Results showed that the rCBF of the right frontal lobe and hippocampus in the operation group was significantly lower than that in the false operation group (P < 0.05).The learning indexes,error number (EN),day of reach standard and total reaction time (TRT) in the operation group,were significantly higher than that in the false operation group (P< 0.05).However,the initiative evasion rate in the operation group was significantly lower than that in the false operation group.The study also found that the rCBF was relatively more,the indexes (EN,the day of reach standard and TRT) relatively fewer,but the initiative evasion rate and the memory keeping rate were relatively more.The positive expression and the average absorbency of Fos and Jun in the operation group were significantly higher than that in the false operation group (P< 0.05).Furthermore,Bax and Bcl-2 positive cells were all increased over time in the operation group,and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group (P<0.01).In conclusion,rCBF decrease can impair the learning and memory function in rats,which may be related to

  14. Plasma-mediated vascular dysfunction in the reduced uterine perfusion pressure model of preeclampsia: a microvascular characterization.

    LENUS (Irish Health Repository)

    Walsh, Sarah K

    2012-01-31

    Preeclampsia is associated with widespread maternal vascular dysfunction, which is thought to be mediated by circulating factor(s). The aim of the study was to characterize vascular function in the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia and to investigate the role of plasma factors in mediating any observed changes in vascular reactivity. Mean arterial blood pressure and vascular function were measured in RUPP and control rats. Mesenteric vessels from both virgin and pregnant rats were exposed for 1 hour or overnight to plasma from both RUPP and control rats and their vascular function assessed. RUPP rats were characterized by severe hypertension, restricted fetal growth, and reduced placental weight (P<0.001). Vasorelaxation was impaired in resistance vessels from RUPP compared with control rats (acetylcholine: R(max) 70+\\/-3 versus 92+\\/-1 [NP] and 93+\\/-3% [sham], P<0.01; bradykinin: 40+\\/-2 versus 62+\\/-2 [NP] and 59+\\/-4% [sham], P<0.001). Incubation of vessels from pregnant (but not virgin) animals with RUPP plasma overnight resulted in an attenuation of vasorelaxant responses (acetylcholine: 63+\\/-7 versus 86+\\/-2%, P<0.05; bradykinin: 35+\\/-5 versus 55+\\/-6%, P<0.001). The residual relaxant response in RUPP plasma-treated vessels was not further attenuated after treatment with N(omega)-nitro-l-arginine methyl ester (acetylcholine: 57+\\/-7 versus 63+\\/-7%, ns; bradykinin: 37+\\/-5 versus 35+\\/-5%, ns). The RUPP rat model is characterized by an impaired response to vasodilators which may be attributable to one or more circulating factors. This plasma-mediated endothelial dysfunction appears to be a pregnancy-dependent effect. Furthermore, nitric oxide-mediated vasorelaxation appears to be absent in RUPP plasma-treated vessels.

  15. Evaluation of craniosynostosis surgery. Technetium-99m-HMPAO SPECT cerebral blood flow study in children with craniosynostosis

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, Tetsuji; Noda, Kojiro; Hayashi, Takashi [St. Mary`s Hospital, Kurume, Fukuoka (Japan); Sato, Kaneshige

    1998-09-01

    Premature fusion of multiple cranial sutures has been associated with increased intracranial pressure and the potential for mental impairment. Isolated craniosynostosis, however, is considered a benign condition primarily reconstructed for aesthetic purposes. A comparative analysis, to assess the differences between pre- and post operatory cerebral perfusion of patients who underwent surgery for simple cranisynostosis, was performed using single positron emission computed tomography ``SPECT`` Images. Cerebral blood flow studies were performed using {sup 99m}Tc-HMPAO SPECT in children with simple cranisynotoses. The subjects were 8 children with craniosynostosis (age, 2 months-9 years). Preoperative revealed regional hypovascularity in the cerebral hemisphere in 5 cases (62%). In 6 patients the cerebral blood flow normalized or increased after craniofacial reconstruction. We demonstrated the presence of regional hypovascularity in the cerebral hemisphere of simple craniosynostotic cases which suggests that early surgery and release is essential to achieve optimal perfusion and brain development. (author)

  16. Evaluation of craniosynostosis surgery. Technetium-99m-HMPAO SPECT cerebral blood flow study in children with craniosynostosis

    International Nuclear Information System (INIS)

    Premature fusion of multiple cranial sutures has been associated with increased intracranial pressure and the potential for mental impairment. Isolated craniosynostosis, however, is considered a benign condition primarily reconstructed for aesthetic purposes. A comparative analysis, to assess the differences between pre- and post operatory cerebral perfusion of patients who underwent surgery for simple cranisynostosis, was performed using single positron emission computed tomography ''SPECT'' Images. Cerebral blood flow studies were performed using 99mTc-HMPAO SPECT in children with simple cranisynotoses. The subjects were 8 children with craniosynostosis (age, 2 months-9 years). Preoperative revealed regional hypovascularity in the cerebral hemisphere in 5 cases (62%). In 6 patients the cerebral blood flow normalized or increased after craniofacial reconstruction. We demonstrated the presence of regional hypovascularity in the cerebral hemisphere of simple craniosynostotic cases which suggests that early surgery and release is essential to achieve optimal perfusion and brain development. (author)

  17. Partial pharmacologic blockade shows sympathetic connection between blood pressure and cerebral blood flow velocity fluctuations.

    Science.gov (United States)

    Hilz, Max J; Wang, Ruihao; Marthol, Harald; Liu, Mao; Tillmann, Alexandra; Riss, Stephan; Hauck, Paulina; Hösl, Katharina M; Wasmeier, Gerald; Stemper, Brigitte; Köhrmann, Martin

    2016-06-15

    Cerebral autoregulation (CA) dampens transfer of blood pressure (BP)-fluctuations onto cerebral blood flow velocity (CBFV). Thus, CBFV-oscillations precede BP-oscillations. The phase angle (PA) between sympathetically mediated low-frequency (LF: 0.03-0.15Hz) BP- and CBFV-oscillations is a measure of CA quality. To evaluate whether PA depends on sympathetic modulation, we assessed PA-changes upon sympathetic stimulation with and without pharmacologic sympathetic blockade. In 10 healthy, young men, we monitored mean BP and CBFV before and during 120-second cold pressor stimulation (CPS) of one foot (0°C ice-water). We calculated mean values, standard deviations and sympathetic LF-powers of all signals, and PAs between LF-BP- and LF-CBFV-oscillations. We repeated measurements after ingestion of the adrenoceptor-blocker carvedilol (25mg). We compared parameters before and during CPS, without and after carvedilol (analysis of variance, post-hoc t-tests, significance: p<0.05). Without carvedilol, CPS increased BP, CBFV, BP-LF- and CBFV-LF-powers, and shortened PA. Carvedilol decreased resting BP, CBFV, BP-LF- and CBFV-LF-powers, while PAs remained unchanged. During CPS, BPs, CBFVs, BP-LF- and CBFV-LF-powers were lower, while PAs were longer with than without carvedilol. With carvedilol, CPS no longer shortened resting PA. Sympathetic activation shortens PA. Partial adrenoceptor blockade abolishes this PA-shortening. Thus, PA-measurements provide a subtle marker of sympathetic influences on CA and might refine CA evaluation. PMID:27206903

  18. Measurements of diagnostic examination performance and correlation analysis using microvascular leakage, cerebral blood volume, and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

    International Nuclear Information System (INIS)

    To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades. A prospective study of 79 patients with cerebral glial tumors underwent DSC-MR imaging. Normalized relative CBV (rCBV) and relative CBF (rCBF) from tumoral (rCBVt and rCBFt), peri-enhancing region (rCBVe and rCBFe), and the value in the tumor divided by the value in the peri-enhancing region (rCBVt/e and rCBFt/e), as well as MVL, expressed as the leakage coefficient K2 were calculated. Hemodynamic variables and tumor grades were analyzed statistically and with Pearson correlations. Receiver operating characteristic (ROC) curve analyses were also performed for each of the variables. The differences in rCBVt and the maximum MVL (MVLmax) values were statistically significant among all tumor grades. Correlation analysis using Pearson was as follows: rCBVt and tumor grade, r = 0.774; rCBFt and tumor grade, r = 0.417; MVLmax and tumor grade, r = 0.559; MVLmax and rCBVt, r = 0.440; MVLmax and rCBFt, r = 0.192; and rCBVt and rCBFt, r = 0.605. According to ROC analyses for distinguishing tumor grade, rCBVt showed the largest areas under ROC curve (AUC), except for grade III from IV. Both rCBVt and MVLmax showed good discriminative power in distinguishing all tumor grades. rCBVt correlated strongly with tumor grade; the correlation between MVLmax and tumor grade was moderate. (orig.)

  19. Evaluation of regional cerebral perfusion after subarachnoid hemorrhage by multi spiral CT perfusion%多层螺旋CT灌注成像评价蛛网膜下腔出血后区域脑灌注不足的实验研究

    Institute of Scientific and Technical Information of China (English)

    王宏清; 杨运俊; 陈伟建; 梁盼; 吴楠; 林伯法

    2012-01-01

    目的 探讨蛛网膜下腔出血(SAH)后多层螺旋CT灌注成像(MS-CTP)评价区域脑灌注减低的应用价值.方法 将32只清洁级雄性日本大耳白兔随机分成两组,其中A组(正常组)8只,B组(SAH组)24只.采用枕大池二次注血法构建兔SAH模型,在造模后第7天行MS-CTP扫描.原始数据通过灌注分析软件获得两侧额顶及基底节的平均脑血流量(CBF)灌注参数图.并于MS-CTP扫描结束后立即处死、取脑,观察SAH情况.结果 两组实验动物额部(t=1.740,P=0.092)、顶部(t=1.868,P=0.072)平均CBF值差异无统计学意义,基底节区差异有统计学意义(t=2.481,P=0.O19).B组实验动物兔基底池可见血凝块分布,而额、顶部未见血凝块存在.结论MS-CTP能够监测SAH后兔脑微循环灌注的变化,并得出区域脑灌注减低与血凝块的分布有关,从而指导SAH后脑灌注减低的早期诊断,有利于临床进行早期的干预治疗.%Objective To explore the chiaical value of cerebral perfusion reduction after subarachnoid hemorrhage(SAH)by multi spiral CT perfusion in rabbits.Methods 32 male Japanese big-ear rabbits of clean level were randomly divided into 2 groups:Group A(n =8),the normal group,were to obtain normal MS-CTP values of rabbit cerebrums;Group B(n =24),the SAH group was made into two-hemorrhage animal models,checked on seven day by multi spiral CT perfusion.The source data was transmitted to the post-processing workstation ADW 4.2.Perfusion parameters maps(CBF)of both sides of frontal,parietal and basal ganglia were got by computing.Each rabbit was killed immediately after scanning,and the spider blood was observed.Results The average CBF value of the two groups:The difference was not statistically significant at the frontal(t =1.740,P =0.092)and parietal(t =1.868,P =0.072); The average values of CBF were significantly decreased at the basal ganglia(t =2.481,P =0.019).Group B showed the distribution of blood clot in the basal cistern,but there was

  20. Preserved regulation of renal perfusion pressure by small and intermediate conductance K-Ca channels in hypertensive mice with or without renal failure

    DEFF Research Database (Denmark)

    Waeckel, L.; Bertin, F.; Clavreul, N.;

    2015-01-01

    The purpose of this study was to assess, in the murine kidney, the mechanisms underlying the endothelium-dependent control of vascular tone and whether or not, in a severe model of hypertension and renal failure, K-Ca channels contribute to its regulation. Wild-type (BL) and double...... hypertensive without kidney disease while ARSL developed severe hypertension and renal failure. In the four groups, methacholine induced biphasic endothelium-dependent responses, a transient decrease in RPP followed by a cyclooxygenase-dependent increase in RPP. In the presence or not of indomethacin, the......-transgenic female mice expressing human angiotensinogen and renin (AR) genes received either control or a high-salt diet associated to a nitric oxide (NO) synthase inhibitor treatment (BLSL and ARSL). Changes in renal perfusion pressure (RPP) were measured in isolated perfused kidneys. BLSL and AR were moderately...

  1. Relationship of Early Spontaneous Type V Blood Pressure Fluctuation after Thrombolysis in Acute Cerebral Infarction Patients and the Prognosis.

    Science.gov (United States)

    Zuo, Lian; Wan, Ting; Xu, Xiahong; Liu, Feifeng; Li, Changsong; Li, Ying; Zhang, Yue; Zhang, Jing; Bao, Huan; Li, Gang

    2016-01-01

    We examined the relationship between an early spontaneous type V blood pressure fluctuation and the post-thrombolysis prognosis of patients with acute cerebral infarction. Patients were admitted consecutively. All patients were categorized into the type V blood pressure fluctuation group or non-type V blood pressure group. Their blood pressure was monitored before thrombolysis and until 6 h after thrombolysis. Baseline data and clinical outcomes were compared. Of 170 patients, 43 (25.2%) had an early type V blood pressure fluctuation. The National Institute of Health Stroke Scale (NIHSS) score before thrombolysis and 24 h after thrombolysis, and the modified Rankin scale score at 90 days differed significantly between the two groups (P V blood pressure fluctuation is common in patients with acute cerebral infarction who received venous thrombolysis, especially if they have a higher NIHSS score before thrombolysis. The type V blood pressure fluctuation may not influence patients' prognosis; however, this needs to be confirmed in future trials. PMID:27278121

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

    International Nuclear Information System (INIS)

    Relative regional cerebral blood flow (rrCBF) was measured by SPET using 99mTc-HMPAO as flow tracer, in 23 patients with normal pressure hydrocephalus (NPH). 1000 MBq 99mTc-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)

  3. Cerebral effects of commonly used vasopressor-inotropes: a study in newborn piglets.

    Directory of Open Access Journals (Sweden)

    Gitte H Hahn

    Full Text Available BACKGROUND: Despite widespread use in sick infants, it is still debated whether vasopressor-inotropes have direct cerebral effects that might affect neurological outcome. We aimed to test direct cerebrovascular effects of three commonly used vasopressor-inotropes (adrenaline, dopamine and noradrenaline by comparing the responses to those of nonpharmacologically induced increases in blood pressure. We also searched for reasons for a mismatch between the response in perfusion and oxygenation. METHODS: Twenty-four piglets had long and short infusions of the three vasopressor-inotropes titrated to raise mean arterial blood pressure (MAP 10 mmHg in random order. Nonpharmacological increases in MAP were induced by inflation of a balloon in the descending aorta. We measured cerebral oxygenation (near-infrared spectroscopy, perfusion (laser-Doppler, oxygen consumption (co-oximetry of arterial and superior sagittal sinus blood, and microvascular heterogeneity (side stream dark field video microscopy. RESULTS: Vasopressor-inotropes increased cerebral oxygenation significantly less (p≤0.01 compared to non-pharmacological MAP increases, whereas perfusion was similar. Furthermore, cerebral total hemoglobin concentration increased significantly less during vasopressor-inotrope infusions (p = 0.001. These physiologic responses were identical between the three vasopressor-inotropes (p>0.05. Furthermore, they induced a mild, although insignificant increase in cerebral metabolism and microvascular heterogeneity (p>0.05. Removal of the scalp tissue did not influence the mismatch (p>0.05. CONCLUSION: We demonstrated a moderate vasopressor-inotrope induced mismatch between cerebral perfusion and oxygenation. Scalp removal did not affect this mismatch, why vasopressor-inotropes appear to have direct cerebral actions. The statistically nonsignificant increases in cerebral metabolism and/or microvascular heterogeneity may explain the mismatch. Alternatively, it

  4. CT Perfusion ASPECTS in the Evaluation of Acute Ischemic Stroke: Thrombolytic Therapy Perspective

    OpenAIRE

    Sillanpaa, Niko; Saarinen, Jukka T.; Rusanen, Harri; Hakomaki, Jari; Lahteela, Arto; Numminen, Heikki; Elovaara, Irina; Dastidar, Prasun; Soimakallio, Seppo

    2011-01-01

    Background and Purpose Advances in the management of acute ischemic stroke and medical imaging are creating pressure to replace the rigid one-third middle cerebral artery (MCA) and non-contrast-enhanced CT (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) thresholds used for the selection of patients eligible for intravenous thrombolytic therapy. The identification of potentially salvageable ischemic brain tissue lies at the core of this issue. In this study, the role of CT perfusion ASP...

  5. Voxel-based analysis of Tc-99 m ECD brain perfusion SPECT in patients with normal pressure hydrocephalus

    International Nuclear Information System (INIS)

    Idiopathic normal pressure hydrocephalus (iNPH) is a reversible dementia characterized by gait disturbance, incontinence and dementia. This study investigates the neuropsychological characteristics and changes of regional cerebral blood flow (rCBF) in patients with iNPH. Ten patients who met the criteria of probable iNPH and 13 normal control subjects were evaluated. The general cognitive function and detailed neuropsychological functions were measured by K-MMSE and comprehensive neuropsychological battery. Tc-99m-ethyl cysteinate dimmer (Tc-99m-ECD) single photon emission computed tomography (SPECT) was performed to measure the rCBF and statistical parametric mapping (SPM) and statistical probabilistic brain anatomic map (SPAM) was applied to the objective analysis of SPECT data. On the neuropsychological examination, all the patients showed abnormality in memory, psychomotor speed and frontal executive function. SPM analysis of SPECT images revealed that rCBF in bilateral thalami, right prefrontal area, bilateral anterior and posterior cingulate gyri, right caudate nucleus, and left parahippocampal gyrus was significantly decreased in patients with iNPH compared to normal controls (uncorrected P<0.005). In SPAM analysis, rCBF reduction was observed in bilateral prefrontal area, anterior, posterior cingulate gyri and caudate nuclei. We have found that rCBF changes occurred predominantly in prefrontal and subcortical areas, the changes were associated with frontal subcortical circuit, and the affected frontal subcortical circuit may contribute to the cognitive decline seen in the iNPH patients. The reduction of rCBF and clinical cognitive impairment are closely connected in patients with iNPH.

  6. Effects of dexamethasone and cox inhibitors on intracranial pressure and cerebral perfusion in the lipopolysaccharide treated rats with hyperammonemia

    DEFF Research Database (Denmark)

    Rohde, Johan; Pedersen, Hans; Bjerring, Peter N;

    2015-01-01

    lipopolysaccharide (LPS) on the brain can be prevented by dexamethasone and cyclooxygenase (COX) inhibitors. METHOD: Fifty-four male Wistar rats, 6 in each group, were divided into the following groups: Saline+ saline; LPS (2 mg/kg)+saline; LPS+indomethacin (10 mg/kg); LPS+diclofenac (10mg/kg); LPS+dexamethasone (2......mg/kg) in experiment A. Experiment-B included the following groups: LPS+NH3 (140 μmol/kg/min)+saline; LPS+NH3+indomethacin; LPS+NH3+diclofenac and LPS+NH3+dexamethasone. ICP was monitored via a catheter placed in cisterna magna and changes in CBF were recorded by laser Doppler flowmetry. RESULTS: LPS...... was associated with a decrease in 6-keto-PGF1α. Dexamethasone only reduced the LPS induced increase in ICP but not CBF, and partly the 6-keto-PGF1α plasma concentration in the combined setup. CONCLUSION: These data indicate that activation of cycloooxygenases is of central importance for development...

  7. Prediction of effectiveness of shunting in patients with normal pressure hydrocephalus by cerebral blood flow measurement and computed tomography cisternography

    International Nuclear Information System (INIS)

    Measurement of cerebral blood flow (CBF) and computed tomography (CT) cisternography were performed in 37 patients with a tentative diagnosis of normal pressure hydrocephalus (NPH) to predict their surgical outcome. The mean CBF of the whole brain was measured quantitatively by single photon emission computed tomography with technetium-99m-hexamethylpropylene amine oxime before surgery. The results of CT cisternography were classified into four patients: type I, no ventricular stasis at 24 hours; type II, no ventricular stasis with delayed clearance of cerebral blush; type III, persistent ventricular stasis with prominent cerebral blush; type IV, persistent ventricular stasis with diminished cerebral blush and/or asymmetrical filling of the sylvian fissures. The mean CBF was significantly lower than that of age-matched controls (p<0.005). Patients with a favorable outcome had a significantly higher mean CBF than patients with an unfavorable outcome (p<0.005). Patients with the type I pattern did not respond to shunting. Some patients with type II and III patterns responded to shunting but improvement was unsatisfactory. Patients with type IV pattern responded well to shunting, and those with a mean CBF of 35 ml/100 g/min or over achieved a favorable outcome. The combination of CBF measurement and CT cisternography can improve the prediction of surgical outcome in patients with suspected NPH. (author)

  8. Effects of the New Aldose Reductase Inhibitor Benzofuroxane Derivative BF-5m on High Glucose Induced Prolongation of Cardiac QT Interval and Increase of Coronary Perfusion Pressure

    Directory of Open Access Journals (Sweden)

    C. Di Filippo

    2016-01-01

    Full Text Available This study investigated the effects of the new aldose reductase inhibitor benzofuroxane derivative 5(6-(benzo[d]thiazol-2-ylmethoxybenzofuroxane (BF-5m on the prolongation of cardiac QT interval and increase of coronary perfusion pressure (CPP in isolated, high glucose (33.3 mM D-glucose perfused rat hearts. BF-5m was dissolved in the Krebs solution at a final concentration of 0.01 μM, 0.05 μM, and 0.1 μM. 33.3 mM D-glucose caused a prolongation of the QT interval and increase of CPP up to values of 190 ± 12 ms and 110 ± 8 mmHg with respect to the values of hearts perfused with standard Krebs solution (11.1 mM D-glucose. The QT prolongation was reduced by 10%, 32%, and 41%, respectively, for the concentration of BF-5m 0.01 μM, 0.05 μM, and 0.1 μM. Similarly, the CPP was reduced by 20% for BF-5m 0.05 μM and by 32% for BF-5m 0.1 μM. BF-5m also increased the expression levels of sirtuin 1, MnSOD, eNOS, and FOXO-1, into the heart. The beneficial actions of BF-5m were partly abolished by the pretreatment of the rats with the inhibitor of the sirtuin 1 activity EX527 (10 mg/kg/day/7 days i.p. prior to perfusion of the hearts with high glucose + BF-5m (0.1 μM. Therefore, BF-5m supplies cardioprotection from the high glucose induced QT prolongation and increase of CPP.

  9. Characteristics of Brain Perfusion in Patients of Parkinson's Disease

    International Nuclear Information System (INIS)

    It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9±6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4±9.2 y/o) as normal controls who had no past illness history were performed 99mTc-HMPAO brain perfusion SPECT and neuropsychological test. At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood

  10. Human cerebral venous outflow pathway depends on posture and central venous pressure

    DEFF Research Database (Denmark)

    Gisolf, J; van Lieshout, J J; van Heusden, K; Pott, F; Stok, W J; Karemaker, J M

    Internal jugular veins are the major cerebral venous outflow pathway in supine humans. In upright humans the positioning of these veins above heart level causes them to collapse. An alternative cerebral outflow pathway is the vertebral venous plexus. We set out to determine the effect of posture...... subjects, before and during a Valsalva manoeuvre in both body positions, correlate highly with model simulation of the jugular cross-sectional area (R(2) = 0.97). The results suggest that the cerebral venous flow distribution depends on posture and CVP: in supine humans the internal jugular veins are the...

  11. Cerebral perfusion scintigraphy and the exploration of dementia syndromes: An illustration with five clinical cases; Scintigraphie cerebrale de perfusion et exploration des syndromes dementiels: illustration a l'aide de cinq cas cliniques

    Energy Technology Data Exchange (ETDEWEB)

    Farid, K.; Perdrisot, R. [Centre Hospitalier Universitaire de Poitiers, Service de Medecine Nucleaire, 86 - Poitiers (France); Habert, M.O. [Centre Hospitalier Universitaire de Pitie-Salpetriere, Service de Medecine Nucleaire, 75 - Paris (France)

    2007-02-15

    The epidemiological evidence suggests that individuals with higher education level have a reduced risk of developing dementia. Because cognitive reserve and its compensation mechanisms may modulate the clinical expression in neuro-degenerative pathology, it is important to study subjects who present mild cognitive disturbance with functional imaging. The cerebral SPECT has been used to determine regional uptake of radiotracer into the brain of patients with cognitive impairment. These abnormalities of blood flow were correlated with cognitive impairment. The cerebral SPECT is also useful to investigate preclinical dementia and to predict the evolution of cognitive disturbance. This article, reports some technical and semeiological notions and illustrate with five clinical cases the scintigraphic aspect of some dementia syndrome. (authors)

  12. Ellagic acid improves electrocardiogram waves and blood pressure against global cerebral ischemia rat experimental models

    OpenAIRE

    Nejad, Khojasteh Hoseiny; Dianat, Mahin; Sarkaki, Alireza; Naseri, Mohammad Kazem Gharib; Badavi, Mohammad; Farbood, Yaghoub

    2015-01-01

    Background: Global cerebral ischemia (GCIR) arises in patients that are shown a variety of clinical difficulty including cardiac arrest, asphyxia, and shock. In spite of advances in understanding of the brain, ischemia and protective effects to improve ischemic injury still remain unknown. The aim of our study was to investigate the effect of ellagic acid (EA) pretreatment in the rat models of global cerebral ischemia reperfusion. Methods: This experimental study was conducted in 2014 at the ...

  13. Comparative study of cerebral blood perfusion SPECT imaging and CT scan in evaluation of the curative effect of hyperbaric oxygen in patients with post-traumatic brain syndrome

    International Nuclear Information System (INIS)

    Objective: To comparatively study the results of cerebral SPECT and cerebral CT before and after hyperbaric oxygen (HBO) treatment in post-traumatic brain syndrome. Methods: HBO was used to treat 288 patients with post-traumatic brain syndrome for two courses, and made therapeutic surveillance and comparative analysis with 99Tcm-ECD SPECT, CT before and after treatment. Results: Before treatment, the positive rate of cerebral SPECT was 80.6%, but the positive rate of CT was only 10.2%; after treatment, 90% of SPECT became negative, and the clinical symptoms of the patients disappeared as SPECT became negative. The results showed that HBO treatment could evidently improve rCBF, and showed that SPECT was superior to CT in surveillance of HBO treatment. Conclusions: 99Tcm-ECD SPECT could play an important role in the diagnosis of post-traumatic brain syndrome and the therapeutic surveillance of HBO

  14. 磁共振灌注加权成像在颅脑胶质瘤分级中的价值研究%Value of MR perfusion weighted imaging in differentiating the tumor grade of cerebral gliomas

    Institute of Scientific and Technical Information of China (English)

    李伟; 龙晚生; 罗学毛; 何义改; 兰勇; 蔡小琴

    2011-01-01

    目的 探讨相对脑血容积(rCBV)、相对脑血流量(rCBF)和相对平均通过时间(rMTT)在鉴别颅脑胶质瘤病理分级中的价值.方法 对病理证实为颅脑胶质瘤的患者(Ⅱ级胶质瘤9例,Ⅲ级胶质瘤11例,Ⅳ级胶质瘤14例)行MR灌注加权成像及常规MRI检查.由灌注加权成像数据获取脑血容积(CBV)图、脑血流量(CBF)图和平均通过时间(MTT)图,计算出rCBV、rCBF和rMTT值.结果 Ⅱ级胶质瘤的rCBV、rCBF和rMTT值分别为2.68±1.37、2.52±1.29和1.02±0.30,Ⅲ级胶质瘤的rCBV、rCBF和rMTT值分别为4.99±2.34、4.77±1.97和1.07±0.15,Ⅳ级胶质瘤的rCBV、rCBF和rMTT值分别为6.69±1.88、6.97±1.73和1.08±0.22,各组间rCBV和rCBF值比较差异有统计学意义(P0.05).结论 MR灌注加权成像能有效地在术前评价颅脑胶质瘤的病理级别,rCBV值结合rCBF值可以更好地对颅脑胶质瘤进行病理分级.%Objective To explore the value of relative cerebral blood volume(rCBV), relative cerebral blood flow(rCBF) and relative mean through time(rMTT) in differentiating the tumor grade of cerebral gliomas. Methods This study involved 34 patients (9 cases of grade Ⅱ,11 cases of grade Ⅲ,14 cases of grade Ⅳ) which were identified as gliomas proved by histopathologic. MR perfusion weighted imaging and conventional MR imaging were underwent on them preoperatively. The perfusion weighted imaging datas were deconvoluted to get a color map of CBV, CBF and MTT. The value of rCBV, rCBF and rMTT of each lesion were calculated and correlated with histopathologic grading of gliomas. Results The value of rCBV, rCBF and rMTT of grade Ⅱ,grade Ⅲ,grade Ⅳ gliomas was (2.68±1.37, 4.99±2.34,6.69±1.88), (2.52±1.29,4.77±1.97,6.97±1.73) and (1.02±0.30,1.07±0.15,1.08±0.22), respectively. The value of rCBV and rCBF had statistically difference in each groups (P0.05).Conclusions MR perfusion weighted imaging is useful in the preoperative assessment of the histopathologic grade

  15. Brain hypoxanthine concentration correlates to lactate/pyruvate ratio but not intracranial pressure in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, Peter Nissen; Hauerberg, John; Jørgensen, Linda;

    2010-01-01

    hypoxanthine, inosine, and lactate/pyruvate (LP) ratio are increased and correlated in patients with acute liver failure. Furthermore, we expect the purines and L/P ratio to correlate with intracranial pressure (ICP) (positively), and cerebral perfusion pressure (CPP) (negatively)....

  16. Perfusion scanning using 99mTc-HMPAO detects early cerebrovascular changes in the diabetic rat

    OpenAIRE

    Fatma J Al-Saeedi

    2008-01-01

    Background 99mTc-HMPAO is a well-established isotope useful in the detection of regional cerebral blood flow. Diabetes gives rise to arterial atherosclerotic changes that can lead to significant end organ dysfunction, prominently affecting perfusion to the heart, kidneys, eyes and brain. In the current study, we investigated the role of 99mTc-HMPAO cerebral perfusion scans in detecting early vascular changes in the diabetic brain. Methods Cerebral perfusion studies were performed on both cont...

  17. Contralateral thalamic hypoperfusion on brain perfusion SPECT

    International Nuclear Information System (INIS)

    Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

  18. Determination of Vascular Reactivity of Middle Cerebral Arteries from Stroke and Spinal Cord Injury Animal Models Using Pressure Myography.

    Science.gov (United States)

    Anwar, Mohammad A; Eid, Ali H

    2016-01-01

    Stroke and other neurovascular derangements are main causes of global death. They, along with spinal cord injuries, are responsible for being the principal cause of disability due to neurological and cognitive problems. These problems then lead to a burden on scarce financial resources and societal care facilities as well as have a profound effect on patients' families. The mechanism of action in these debilitating diseases is complex and unclear. An important component of these problems arises from derangement of blood vessels, such as blockage due to clotting/embolism, endothelial dysfunction, and overreactivity to contractile agents, as well as alteration in endothelial permeability. Moreover, the cerebro-vasculature (large vessels and arterioles) is involved in regulating blood flow by facilitating auto-regulatory processes. Moreover, the anterior (middle cerebral artery and the surrounding region) and posterior (basilar artery and its immediate locality) regions of the brain play a significant role in triggering the pathological progression of ischemic stroke particularly due to inflammatory activity and oxidative stress. Interestingly, modifiable and non-modifiable cardiovascular risk factors are responsible for driving ischemic and hemorrhagic stroke and spinal cord injury. There are different stroke animal models to examine the pathophysiology of middle cerebral and basilar arteries. In this context, arterial myography offers an opportunity to determine the etiology of vascular dysfunction in these diseases. Herein, we describe the technique of pressure myography to examine the reactivity of cerebral vessels to contractile and vasodilator agents and a prelude to stroke and spinal cord injury. PMID:27604741

  19. Local blood pressure associates with the degree of luminal stenosis in patients with atherosclerotic disease in the middle cerebral artery.

    Science.gov (United States)

    Jiang, Yuanliang; Peng, Wenjia; Teng, Zhongzhao; Gillard, Jonathan H; Hong, Bo; Liu, Qi; Lu, Jianping

    2016-01-01

    The mechanism underlying atherosclerotic ischemic events within the middle cerebral artery (MCA) is unclear. High structural stress induced by blood pressure might be a potential aetiology as plaque rupture occurs when such mechanical loading exceeds its material strength. To perform reliable analyses quantifying the mechanical loading within a plaque, the local blood pressure is needed. However, data on MCA blood pressure is currently lacking. In this study, the arterial pressure proximal to the stenotic site in the MCA was measured in 15 patients scheduled for intervention. The relationships between these local measurements and pre-intervention and intra-intervention non-invasive arm measurements were assessed. The impact of luminal stenosis on the local blood pressure was quantified. Compared with the pre-intervention arm measurement, the intra-intervention arm pressure decreased significantly by 23.9 ± 11.8 and 9.3 ± 14.7 % at diastole and systole, respectively. The pressure proximal to the stenosis was much lower than the pre-intervention arm measurement (diastole: 65.3 ± 15.7 vs 82.0 ± 9.7, p pressure in the MCA in patients with stenosis pressure (22.8 ± 6.4 vs 11.1 ± 8.3, p = 0.01; unit: mmHg). However, diastolic pressure remained unaffected (69.2 ± 9.3 vs 62.8 ± 19.0, p = 0.58; unit: mmHg). In conclusion, the obtained results are helpful in understanding the local hemodynamic environment modulated by the presence of atherosclerosis. The local pressure measurements can be used for computational analysis to quantify the critical mechanical condition within an MCA lesion. PMID:27349223

  20. Pharmacological and molecular comparison of K(ATP) channels in rat basilar and middle cerebral arteries

    DEFF Research Database (Denmark)

    Ploug, Kenneth Beri; Edvinsson, Lars; Olesen, Jes;

    2006-01-01

    ATP-sensitive potassium (K(ATP)) channels play an important role in the regulation of cerebral vascular tone. In vitro studies using synthetic K(ATP) channel openers suggest that the pharmacological profiles differ between rat basilar arteries and rat middle cerebral arteries. To address this issue......, we studied the possible involvement of endothelial K(ATP) channels by pressurized arteriography after luminal administration of synthetic K(ATP) channel openers to rat basilar and middle cerebral arteries. Furthermore, we examined the mRNA and protein expression profile of K(ATP) channels to rat...... basilar and middle cerebral arteries using quantitative real-time PCR (Polymerase Chain Reaction) and Western blotting, respectively. In the perfusion system, we found no significant responses after luminal application of three K(ATP) channel openers to rat basilar and middle cerebral arteries. In...

  1. Cerebral metabolism and perfusion in MR-negative individuals with refractory focal epilepsy assessed by simultaneous acquisition of 18F-FDG PET and arterial spin labeling

    OpenAIRE

    Galazzo, I. B.; Mattoli, M. V.; Pizzini, F. B.; Vita, E.; Barnes, A.; Duncan, J.S.; Jager, R.; Golay, X.; Bomanji, J. B.; Koepp, M.; Groves, A M; Fraioli, F.

    2016-01-01

    The major challenge in pre-surgical epileptic patient evaluation is the correct identification of the seizure onset area, especially in MR-negative patients. In this study, we aimed to: (1) assess the concordance between perfusion, from ASL, and metabolism, from 18F-FDG, acquired simultaneously on PET/MR; (2) verify the utility of a statistical approach as supportive diagnostic tool for clinical readers. Secondarily, we compared 18F-FDG PET data from the hybrid PET/MR system with those acquir...

  2. Comparative study of the uniform and non uniform attenuation correction in cerebral perfusion scintigraphy with E.C.D.-99mTc

    International Nuclear Information System (INIS)

    Brain perfusion scintigraphy is a functional imaging currently used for the evaluation of patients with cognitive impairment. Although widely available, this technique is known as less sensitive than 18FDG-PET. The optimization of technical parameters for images acquiring and processing using a non uniform attenuation correction (A.C.) and a correction of distributed (C.D.) could improve its performance. The objective of this study is to compare the non uniform correction obtained by attenuation map of computed tomography (CT) combined with CT-C.D. and C.D. + CT uniform C.A. using the Chang method considering the distributed alone (coefficient = 0.09 cm-1)

  3. Outflow facility efficacy of five drugs in enucleated porcine eyes by a method of constant-pressure perfusion

    OpenAIRE

    Li, Ning; Shi, Hui-Min; Cong, Lin; Lu, Zhao-Zeng; Ye, Wen; Zhang, Yu-yan

    2015-01-01

    This study aimed to characterize a technique that assesses the outflow facility (C) efficacy of five kinds of IOP-lowering drugs commonly used clinically in enucleated porcine Eyes. Eyes were perfused at 15 mmHg with GPBS first to establish the baseline outflow facility (C0). Then the anterior chamber contents were exchanged for GPBS with corresponding concentration eye drops (4.9×103 nM Brimonidine, 41.1 nM Latanoprost, 3.4×103 nM Levobunolol, 3.0×103 nM Brinzolamide, 8.3×103 nM Pilocarpine)...

  4. Middle cerebral artery flow velocity and blood flow during exercise and muscle ischemia in humans

    DEFF Research Database (Denmark)

    Jørgensen, L G; Perko, M; Hanel, B; Schroeder, T V; Secher, N H

    1992-01-01

    Changes in middle cerebral artery flow velocity (Vmean), measured by transcranial Doppler ultrasound, were used to determine whether increases in mean arterial pressure (MAP) or brain activation enhance cerebral perfusion during exercise. We also evaluated the role of "central command......," mechanoreceptors, and/or muscle "metaboreceptors" on cerebral perfusion. Ten healthy subjects performed two levels of dynamic exercise corresponding to a heart rate of 110 (range 89-134) and 148 (129-170) beats/min, respectively, and exhaustive one-legged static knee extension. Measurements were continued during 2......-2.5 min of muscle ischemia. MAP increased similarly during static [114 (102-133) mmHg] and heavy dynamic exercise [121 (104-136) mmHg] and increased during muscle ischemia after dynamic exercise. During heavy dynamic exercise, Vmean increased 24% (10-47%; P less than 0.01) over approximately 3 min despite...

  5. Vessel encoded arterial spin labeling with cerebral perfusion: preliminary study%血管编码动脉自旋标记MR脑灌注成像初步研究

    Institute of Scientific and Technical Information of China (English)

    吴冰; 蒋学祥; 方竞; 王晶; 郭佳; 章蓓茹; 肖江喜; 谢晟; Eric C.Wong; 张珏; 王霄英

    2008-01-01

    目的 初步应用血管编码动脉自旋标记MR脑灌注成像技术选择件标记双侧颈内动脉及后循环的血流分布区.方法 使用伪连续动脉自旋标记成像方法 对7名健康志愿者和6例脑血管病患者的左、右颈内动脉及椎基底动脉编码进行头部横断而成像和图像后处理,得到来源于上述不同血管的脑血流量(CBF)的灌注分布图,计算7名志愿者的双侧大脑厌、白质及半脑的CBF.比较脑血管病患者的血流分布结果 与DSA图像的一致性及低灌注区域与液体衰减反转恢复(FLAIR)T2WI的高信号区域大小.结果 定量测量正常志愿者的半CBF为(32.6±4.3)ml·min-1·100 g-1,脑白质血流最(10.8±0.9)ml·min-1·100 g-1,脑灰质血流量(55.6±2.9)ml·min-1·100 g-1.脑血管病患者的脑血流分布异常、侧支循环血流分布与DSA对应良好;所有患者低灌注区域比FLAIR T2WI显示的高信号区域范围更大.结论 血管编码动脉自旋标记MR脑灌注成像可以无创地定性并定量不同血管来源的脑血供.%Objective To evaluate a noninvasive vessel encoded imaging for selective mapping of the flow territories of the left and right internal carotid arteries and vertebral-basilar arteries. Methods Seven volunteers [(33.5±4.1) years ; 3 men, 4 women] and 6 patients [(55.2 ± 3.2) years; 2 men,4women] were given written informed consent approved by the institutional review board before participating in the study. A pseudo-continuous tagging pulse train is modified to encode all vessels of interest. The selectivity of this method was demonstrated. Regional perfusion imaging was developed on the same arterial spin labeling sequence. Perfusion-weighted images of the selectively labeled cerebral arteries were obtained by subtraction of the labeled from control images. The CBF values of hemisphere, white matter, and gray matter of volunteers were calculated. The vessel territories on patients were compared with DSA. The low

  6. Assessment of cerebral perfusion and cerebrovascular reserve in insulin-dependent diabetic patients without central neurological symptoms by means of {sup 99m}Tc-HMPAO SPET with acetazolamide

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Bonilla, J.F.; Quirce, R.; Hernandez, A.; Vallina, N.K.; Guede, C.; Banzo, I.; Amado, J.A.; Carril, J.M. [Nuclear Medicine Service, University Hospital Marques de Valdecilla, Santander (Spain)

    2001-11-01

    The detection of subclinical abnormalities in cerebral blood flow could be of great value in identifying diabetic patients at risk of stroke. The aim of this study was to assess the contribution of semiquantified post-acetazolamide technetium-99m hexamethylpropylene amine oxime single-photon emission tomography ({sup 99m}Tc-HMPAO SPET) in 15 diabetic patients with no clinical history of central neurological disease. After baseline {sup 99m}Tc-HMPAO SPET, a second SPET scan was acquired after activation of the cerebrovascular reserve (CVR) with an injection of 1 g of acetazolamide (post-ACZ SPET). Semiquantitative analysis was made in 16 regions of interest (ROIs) drawn for each of the three supratentorial slices selected, and in two ROIs in the infratentorial slice. The CVR was calculated in each ROI by subtracting the decay-corrected baseline images from those obtained in the post-ACZ SPET and expressed as the percent increase in the average counts between the two scans. Baseline perfusion and CVR values in the study group were compared with the corresponding values in a control group. Of 750 cortical ROIs studied, 332 showed a decreased CVR (44.3%). The baseline perfusion SPET study showed hypoperfusion in 65 ROIs (8.6%) and hyperperfusion in 56 (7.4%). Of the 65 hypoperfused regions, 66.2% had a normal CVR and 33.8% had a decreased CVR, whereas of the 56 hyperperfused regions, 51.8% had a CVR within normal limits and 48.2% showed a decreased CVR. In conclusion, in comparison with baseline {sup 99m}Tc-HMPAO SPET, the ACZ activation test provided additional information in the study of cerebrovascular impairment, and allowed characterisation of the subclinical abnormalities in the population studied. The technique may therefore prove useful in evaluating future preventive strategies for stroke in diabetic patients. (orig.)

  7. Non-invasive and quantitative evaluation of peripheral vascular resistances in rats by combined NMR measurements of perfusion and blood pressure using ASL and dynamic angiography.

    Science.gov (United States)

    Ménard, Jacques C; Giacomini, Eric; Baligand, Céline; Fromes, Yves; Carlier, Pierre G

    2010-02-01

    The in vivo determination of peripheral vascular resistances (VR) is crucial for the assessment of arteriolar function. It requires simultaneous determination of organ perfusion (F) and arterial blood pressure (BP). A fully non-invasive method was developed to measure systolic and diastolic BP in the caudal artery of rats based on dynamic NMR angiography. A good agreement was found between the NMR approach and the gold standard techniques (linear regression slope = 0.98, R(2) = 0.96). This method and the ASL-MRI measurement of skeletal muscle perfusion were combined into one single NMR experiment to quantitatively evaluate the local vascular resistances in the calf muscle of anaesthetized rats, in vivo and non-invasively 1) at rest: VR = 7.0 +/- 1.0 mmHg x min 100 g x ml(-1), F = 13 +/- 3 ml min(-1) x 100 g(-1) and mean BP (MBP) = 88 +/- 10 mmHg; 2) under vasodilator challenge (milrinone): VR = 3.7 +/- 1.1 mmHg min x 100 g ml(-1), F = 21 +/- 4 ml min(-1) x 100 g(-1) and MBP = 75 +/- 14 mmHg; 3) under vasopressor challenge (norepinephrine): VR = 9.8 +/- 1.2 mmHg min 100 g ml(-1), F = 14 +/- 3 ml min(-1) x 100 g(-1) and MBP = 137 +/- 2 mmHg. PMID:19795372

  8. Cerebral infarction showed hyperperfusion pattern on radionuclide cerebral angiography

    International Nuclear Information System (INIS)

    Four patients of middle cerebral infarctin showed hyperperfusion on radionuclide cerebral angiography and fan-shape accumulation at the area of middle cerebral artery on early and delayed brain scan. In these patients, bone scanning agents such as sup(99m)Tc-EHDP or sup(99m)Tc-MDP also prominently accumulated at the area of infarction. These findings were observed on the study when it was performed within seventeen days after attack, but reexamination tended to show normal or decreased perfusion on radionuclide cerebral angiography and improve abnormal accumulation on brain scans. The clinical diagnosis of these three patients were cerebral embolism with heart disease, but one patient was internal carotid artery occlusion. The prognosis of all patients were very good. The hyperperfusion on radionuclide cerebral angiography of these patients represents the luxury perfusion in the lesion and these infarction has been called hot stroke by Yarnell et al. (author)

  9. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO2

    International Nuclear Information System (INIS)

    Measurement of 133Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO2 at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO2 of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption

  10. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Murkin, J.M.; Farrar, J.K.; Tweed, W.A.; McKenzie, F.N.; Guiraudon, G.

    1987-09-01

    Measurement of /sup 133/Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO/sub 2/ at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO/sub 2/ of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption.

  11. Skin perfusion pressure measured with a photo sensor in an air-filled plastic balloon: validity and reproducibility on the lower leg in normal subjects and patients suspected of obliterative arterial disease

    International Nuclear Information System (INIS)

    An inflatable small plastic bag including a photo sensor was constructed for measurement of skin perfusion pressure avoiding the rim of the photo sensor over bony and tendineous surfaces of the tibia below the knee, at the ankle, and on the dorsal forefoot. Compression was obtained using a conical blood pressure cuff with continuous decrease from suprasystolic arm pressure. The validity of skin perfusion pressure with the new device was compared to that of isotope washout below the knee in normal subjects and in patients with an ischemic forefoot with acceptable agreement. The method had a high reproducibility within and between days in normal subjects. Compared to systolic arterial pressure measured using a strain gauge with a cuff on the ankle in normal subjects and patients with intermittent claudication the new device showed blood pressure in the skin closer to the diastolic pressure. The new pressure device thus had acceptable validity and reproducibility for estimation of the skin perfusion pressure and can be used on bony and tendineous sites on the lower limb in regions where critical wound healing is frequent, e.g. ankle and forefoot

  12. Effects of nimodipine on cerebral blood flow and cerebrospinal fluid pressure after cardiac arrest: correlation with neurologic outcome.

    Science.gov (United States)

    Forsman, M; Aarseth, H P; Nordby, H K; Skulberg, A; Steen, P A

    1989-04-01

    Fifty-one patients were included in a blind randomized study to evaluate whether the Ca-blocker nimodipine could influence cerebral blood flow (CBF) or cerebrospinal fluid pressure (CSFP) during the cerebral hypoperfusion period that follows resuscitation from cardiac arrest and to determine whether changes in CBF correlate with neurologic outcome. CBF measured 1 to 4 hours after arrest with the use of 133Xe intravenous was significantly greater with nimodipine than with placebo (27 +/- 3 versus 13 +/- 1 ml.100 g-1.min-1 at 3 hours), but with no significant difference at 24 hours. There was no clinical evidence of seriously increased CSFP in any patient in either group the first 48 hours. Mean arterial pressure was significantly lower (86 +/- 4 versus 101 +/- 4 mm Hg at 3 hours), and antiarrhythmic drugs were used significantly less frequently in the nimodipine group than in the placebo group. Twelve patients in each group eventually regained consciousness. There was no significant difference in neurologic status between the two groups at any point, and no positive correlation between CBF in the hypoperfusion period and neurologic outcome. PMID:2929976

  13. Evaluation of the Extension of the Cerebral Blood Flow and its Main Parameters

    CERN Document Server

    Gersten, A

    1999-01-01

    Among the major factors controlling the cerebral blood flow (CBF) - cerebral perfusion pressure, arterial partial pressure of oxygen (PaO2), cerebral metabolism, arterial partial pressure of carbon dioxide (PaCO2), and cardiac output, the effect of PaCO2 is peculiar in being independent of autoregulatory CBF mechanisms and it allows to explore the full range of the CBF. We have developed a simple physical model, and have derived a simple four parameter formula, relating the CBF to PaCO2. The parameters can be extracted in an easy way, directly from the experimental data. With this model five experimental data sets of human, rats, baboons and dogs were well fitted. The same type of parametrization was also used successfully for fitting experimental data of PaO2 of dogs. We have also looked on the dependence of the parameters on other factors and were able to evaluate their dependence on the mean arterial blood pressure.

  14. Brain perfusion spect imaging with 99mTc-HM-PAO in Parkinson's disease

    International Nuclear Information System (INIS)

    Forty patients with Parkinson's disease were studied using 99mTc-HM-PAO brain perfusion SPECT. 62.5% (25 cases) showed abnormal blood perfusion. Among them 55% showed local decreased blood perfusion of cerebral cortex, 22% showed asymmetric decreased blood perfusion in basal gaglia, 10% showed decreased uptake of tracer in cerebellum. The pathophysiologic basis of the abnormality of brain blood perfusion were briefly discussed

  15. A venous outflow method for measurement of rapid changes of the cerebral blood flow and oxygen consumption in the rat.

    Science.gov (United States)

    Nilsson, B; Siesjö, B K

    1983-01-01

    A technique for continuous measurement of cerebral venous outflow in the rat is described. The method involves cannulation of one retroglenoid vein close to its exit from the skull, and diversion of cerebral venous blood through a closed extracorporal circuit with a drop recording device, the blood being returned to the central venous circulation via a catheter in the external jugular vein. Occlusion of the contralateral retroglenoid vein increases measured flow and minimizes extracerebral contamination of the diverted cerebral venous blood. The venous outflow system is not further isolated from cerebral or potential extracerebral collaterals. Thus, the mass of tissue drained cannot be exactly defined anatomically. However, the experiments involving changes of PP, arterial CO2 tension, and induction of epileptic seizure activity, and simultaneous indirect measurements with radioactive tracer technique, indicate that significant extracerebral contamination does not occur and that in short term measurements the venous outflow represents cerebral blood flow (CBF) in a constant mass of (dorsal and central, mainly forebrain) cerebral tissue. Measurement of arterial blood pressure and pressure in the cisterna magna allows calculation of cerebral perfusion pressure (PP). By simultaneous measurement of arterial and cerebral venous oxygen content changes in cerebral oxygen consumption (CMRO2) can be calculated. The method has been applied to document several situations of transient CBF and CMRO2 changes. PMID:6658967

  16. A voxel-based analysis of cerebral perfusion with 99mTc-ECD brain SPECT in obsessive-compulsive disorder

    International Nuclear Information System (INIS)

    Many neuroimaging studies, especially metabolic imaging with PET, showed a specific frontal-subcortical brain circuit connecting the orbitofrontal cortex (OFC), anterior cingulate gyrus, elements of basal ganglia and thalamus is involved in obsessive-compulsive disorder (OCD). Despite consistent metabolic alteration on PET, blood flow studies with SPECT were inconsistent and various cortical and subcortical structures showed abnormal perfusion patterns. In this study, brain SPECT images of seven patients with OCD were evaluated with a sophisticated method of statistical parametric mapping (SPM). Seven patients with severe, primary OCD (6 males and 1 female) with mean age of 25.4 4.7 yrs (20-32 yrs) were studied. The SPECT data of the patients were compared with those of healthy subjects and patients with drug nave schizophrenia using SPM. The SPM parameters were p value of 0.001 with Z value of 3.09 (higher threshold ) or p value of 0.005 with Z value 2.58 (lower threshold). On a higher threshold (p<0.01),five of the seven patients showed hyperperfusion within the anterior cingulate cortex, however, hyperperfusion within OFC or caudate nucleus was seen in only one patient. On a lower threshold (p<0.005), hyperperfusion within the anterior cingulate cortex was seen in all patients, and followed by thalamus (n=5), lentiform nucleus (n=4), caudate nucleus (n=3), and OFC (n=3). Perfusion within the anterior cingulate cortex was also increased in OCD compared with drug nave schizophrenia. Anterior cingulate cortex appears to be an important anatomical structure in the pathogenesis of OCD symptoms. Brain SPECT using a sophisticated analysis method of SPM is useful for the diagnosis of OCD and differentiation from schizophrenia

  17. A voxel-based analysis of cerebral perfusion with {sup 99m}Tc-ECD brain SPECT in obsessive-compulsive disorder

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Tae Joo; Lee, Jong Doo; Kim, Hee Joung; Chang, Jin Woo; Kim, Chan Hyung; Lee, Hong Shick; Min, Sung Kil; Chung, Sang Sup [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    2000-07-01

    Many neuroimaging studies, especially metabolic imaging with PET, showed a specific frontal-subcortical brain circuit connecting the orbitofrontal cortex (OFC), anterior cingulate gyrus, elements of basal ganglia and thalamus is involved in obsessive-compulsive disorder (OCD). Despite consistent metabolic alteration on PET, blood flow studies with SPECT were inconsistent and various cortical and subcortical structures showed abnormal perfusion patterns. In this study, brain SPECT images of seven patients with OCD were evaluated with a sophisticated method of statistical parametric mapping (SPM). Seven patients with severe, primary OCD (6 males and 1 female) with mean age of 25.4 4.7 yrs (20-32 yrs) were studied. The SPECT data of the patients were compared with those of healthy subjects and patients with drug nave schizophrenia using SPM. The SPM parameters were p value of 0.001 with Z value of 3.09 (higher threshold ) or p value of 0.005 with Z value 2.58 (lower threshold). On a higher threshold (p<0.01),five of the seven patients showed hyperperfusion within the anterior cingulate cortex, however, hyperperfusion within OFC or caudate nucleus was seen in only one patient. On a lower threshold (p<0.005), hyperperfusion within the anterior cingulate cortex was seen in all patients, and followed by thalamus (n=5), lentiform nucleus (n=4), caudate nucleus (n=3), and OFC (n=3). Perfusion within the anterior cingulate cortex was also increased in OCD compared with drug nave schizophrenia. Anterior cingulate cortex appears to be an important anatomical structure in the pathogenesis of OCD symptoms. Brain SPECT using a sophisticated analysis method of SPM is useful for the diagnosis of OCD and differentiation from schizophrenia.

  18. Middle cerebral artery blood velocity during rowing

    DEFF Research Database (Denmark)

    Secher, Niels Henry; Pott, F; Knudsen, L.;

    1997-01-01

    original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler......original,arterial blood pressure,central venous pressure,cerebral blood flow, exercise, transcranial Doppler...

  19. Skin perfusion pressure measured with a photo sensor in an air-filled plastic balloon: validity and reproducibility on the lower leg in normal subjects and patients suspected of obliterative arterial disease

    DEFF Research Database (Denmark)

    Nielsen, Steen Levin; Nielsen, Anne Lerberg; Vind, Susanne Haase;

    2011-01-01

    An inflatable small plastic bag including a photo sensor was constructed for measurement of skin perfusion pressure avoiding the rim of the photo sensor over bony and tendineous surfaces of the tibia below the knee, at the ankle, and on the dorsal forefoot. Compression was obtained using a conical...

  20. Human cerebral circulation. Positron emission tomography studies

    International Nuclear Information System (INIS)

    We reviewed the literature on human cerebral circulation and oxygen metabolism, as measured by positron emission tomography (PET), with respect to normal values and of regulation of cerebral circulation. A multicenter study in Japan showed that between-center variations in cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) values were not considerably larger than the corresponding within-center variations. Overall mean±SD values in cerebral cortical regions of normal human subjects were as follows: CBF=44.4±6.5 ml/100 ml/min; CBV=3.8±0.7 ml/100 ml; OEF=0.44±0.06; CMRO2=3.3±0.5 ml/100 ml/min (11 PET centers, 70 subjects). Intrinsic regulation of cerebral circulation involves several factors. Autoregulation maintains CBF in response to changes in cerebral perfusion pressure; chemical factors such as PaCO2 affect cerebral vascular tone and alter CBF; changes in neural activity cause changes in cerebral energy metabolism and CBF; neurogenic control of CBF occurs by sympathetic innervation. Regional differences in vascular response to changes in PaCO2 have been reported, indicating regional differences in cerebral vascular tone. Relations between CBF and CBV during changes in PaCO2 and during changes in neural activity were in good agreement with Poiseuille's law. The mechanisms of vascular response to neural activation and deactivation were independent on those of responses to PaCO2 changes. CBV in a brain region is the sum of three components: arterial, capillary and venous blood volumes. It has been reported that the arterial blood volume fraction is approximately 30% in humans and that changes in human CBV during changes in PaCO2 are caused by changes in arterial blood volume without changes in venous blood volume. These findings should be considered in future studies of the pathophysiology of cerebrovascular diseases. (author) 136 refs

  1. Adverse effects of intravenous acetazolamide administration for evaluation of cerebrovascular reactivity using brain perfusion single-photon emission computed tomography in patients with major cerebral artery steno-occlusive diseases

    International Nuclear Information System (INIS)

    Adverse effects of intravenous acetazolamide administration for evaluation of cerebrovascular reactivity using brain perfusion single-photon emission computed tomography (SPECT) were prospectively investigated in 100 patients with major cerebral artery, atherosclerotic, and steno-occlusive diseases. All patients underwent two SPECT studies (with and without acetazolamide challenge) at an interval of 2 or 3 days, received a questionnaire immediately after each SPECT study, and returned the answered questionnaire within 7 days after the study. None of the 100 patients studied experienced any symptoms during the SPECT study without acetazolamide challenge. Sixty-three patients (63%) developed symptoms during the SPECT study with acetazolamide challenge, such as headache, nausea, dizziness, tinnitus, numbness of the extremities, motor weakness of the extremities, and general malaise 1-3 hours (mean 1.6 hours) after administration of acetazolamide, and these symptoms lasted for 0.5-72 hours (mean 7.9 hours). Multivariate statistical analysis revealed that younger age (95% confidence interval [CI] 0.896-0.980, p=0.0047) and female sex (95% CI 1.178-16.129, p=0.0274) were significantly associated with development of symptoms with acetazolamide challenge. The incidences of the development of symptoms with acetazolamide challenge were 91% (21/23) and 41% (12/29) in subgroups of women <70 years and men ≥70 years, respectively. Patients should be informed of such adverse effects of intravenous acetazolamide administration prior to the acetazolamide challenge test for evaluation of cerebrovascular reactivity. (author)

  2. 基于动脉自旋标记技术的内侧颞叶癫痫病人脑血流灌注成像研究%A Cerebral Blood Flow Perfusion Analysis in Patients with Temporal Lobe Epilepsy by Use of Arterial Spin Labeled Perfusion MR Imaging

    Institute of Scientific and Technical Information of China (English)

    郭超; 郑罡; 陈春晓; 沈连芳; 张志强; 王利; 卢光明

    2011-01-01

    Using arterial spin labeling (ASL), the authors have studied and analyzed the present of perfusion abnormalities in patients with mesial temporal lobe epilepsy (mTLE). 30 interictal patients with mTLE and hippocampal sclerosis (HS) including 16 patients with left mTLE (LTLE) and 14 patients with right mTLE (RTLE), and 22 healthy volunteers underwent pulsed ASL (PASL) in resting state. Relative cerebral blood flow (rCBF) was calculated and compared using group analysis of statistic parameters mapping and perfusion asymmetric index of region of interest. The results demonstrated that compared to controls, the rCBF of epileptics decreased in bilateral parahippocampal, fusiform, frontal lobe, temporal lobe and ipsilateral insula, and hippocampus in patients with LTLE, bilateral hippocampus, parahippocampal, fusiform, frontal lobe and temporal lobe, and ipsilateral amygdale and insula in patients with RTLE, but decreasing degree and area in ipsilateral side was much more than contralateral side. This study provided evidences that the HS may cause functional abnormalities in seizure zones and influence the whole brain through seizures in patients with mTLE.%基于动脉自旋标记(arterial spin labeling,ASL)技术,分析内侧颞叶癫痫(mesialtemporal lobe epilepsy,mTLE)患者大脑血流灌注(perfusion)的改变情况.在静息态下,采集了30例内侧颞叶癫痫伴单侧海马硬化发作间期患者(其中左侧16例,右侧14例)及22例健康志愿者的ASL数据,并通过计算获取其相对脑血流量(relative CBF,rCBF)及灌注不对称率(asymmetric index,AI).癫痫病人与正常人的比较结果表明:左侧mTLE患者在两侧海马旁回、梭状回、额叶、颞叶和患侧海马回及岛叶,右侧mTLE患者在两侧海马回、海马旁回、额叶、颞叶和患侧杏仁核及岛叶,rCBF均有所下降,且患侧的下降程度和范围均大于对侧.说明mTLE患者的海马硬化可能导致了痫灶区功能异常,并通过癫痫的发作影响到全脑.

  3. High-altitude cerebral oedema mimicking stroke.

    Science.gov (United States)

    Yanamandra, Uday; Gupta, Amul; Patyal, Sagarika; Varma, Prem Prakash

    2014-01-01

    High-altitude cerebral oedema (HACO) is the most fatal high-altitude illness seen by rural physicians practising in high-altitude areas. HACO presents clinically with cerebellar ataxia, features of raised intracranial pressure (ICP) and coma. Early identification is important as delay in diagnosis can be fatal. We present two cases of HACO presenting with focal deficits mimicking stroke. The first patient presented with left-sided hemiplegia associated with the rapid deterioration in the sensorium. Neuroimaging revealed features suggestive of vasogenic oedema. The second patient presented with monoplegia of the lower limb. Neuroimaging revealed perfusion deficit in anterior cerebral artery territory. Both patients were managed with dexamethasone and they improved dramatically. Clinical picture and neuroimaging closely resembled acute ischaemic stroke in both cases. Thrombolysis in these patients would have been disastrous. Recent travel to high altitude, young age, absence of atherosclerotic risk factors and features of raised ICP concomitantly directed the diagnosis to HACO. PMID:24671373

  4. Computed tomography perfusion imaging in acute stroke

    International Nuclear Information System (INIS)

    The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel-by-pixel analysis allowed generation of perfusion maps. In two cases, CT-perfusion imaging usefully excluded acute stroke, including one patient in whom a low-density area on conventional CT was subsequently proven to be tumour Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis. Copyright (2002) Blackwell Science Pty Ltd

  5. Effects of Topical Bimatoprost 0.01% and Timolol 0.5% on Circadian IOP, Blood Pressure and Perfusion Pressure in Patients with Glaucoma or Ocular Hypertension: A Randomized, Double Masked, Placebo-Controlled Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Francesco Oddone

    Full Text Available To compare the 24-hour (24h effects on intraocular pressure (IOP and cardiovascular parameters of timolol 0.5% and bimatoprost 0.01% in open angle glaucoma and ocular hypertensive subjects.In this prospective, randomized, double masked, crossover, clinical trial, after washout from previous medications enrolled subjects underwent 24h IOP, blood pressure (BP and heart rate (HR measurements and were randomized to either topical bimatoprost 0.01% at night plus placebo in the morning or to timolol 0.5% bid. After 8 weeks of treatment a second 24h assessment of IOP, BP and HR was performed and then subjects switched to the opposite treatment for additional 8 weeks when a third 24h assessment was performed. The primary endpoint was the comparison of the mean 24h IOP after each treatment. Secondary endpoints included the comparisons of IOP at each timepoint of the 24h curve and the comparison of BP, HR, ocular perfusion pressure and tolerability.Mean untreated 24h IOP was 20.3 mmHg (95%CI 19.0 to 21.6. Mean 24h IOP was significantly lower after 8 weeks of treatment with bimatoprost 0.01% than after 8 weeks of treatment with timolol 0.5% bid (15.7 vs 16.8 mmHg, p = 0.0003. Mean IOP during the day hours was significantly reduced from baseline by both drugs while mean IOP during the night hours was reduced by -2.3 mmHg (p = 0.0002 by bimatoprost 0.01% plus placebo and by -1.1 mmHg by timolol 0.5% bid (p = 0.06. Timolol 0.5% significantly reduced the mean 24h systolic BP from baseline, the diastolic BP during the day hours, the HR during the night hours, and the mean 24h systolic ocular perfusion pressure.Both Bimatoprost 0.01% and Timolol 0.5% are effective in reducing the mean 24h IOP from an untreated baseline but Bimatoprost 0.01% is more effective than timolol 0.5% throughout the 24h. Timolol 0.5% effect on IOP is reduced during the night hours and is associated with reduced BP, HR and ocular perfusion pressure.EU Clinical Trial Register and Eudra

  6. The cerebral effects of ascent to high altitudes.

    Science.gov (United States)

    Wilson, Mark H; Newman, Stanton; Imray, Chris H

    2009-02-01

    Cellular hypoxia is the common final pathway of brain injury that occurs not just after asphyxia, but also when cerebral perfusion is impaired directly (eg, embolic stroke) or indirectly (eg, raised intracranial pressure after head injury). We Review recent advances in the understanding of neurological clinical syndromes that occur on exposure to high altitudes, including high altitude headache (HAH), acute mountain sickness (AMS), and high altitude cerebral oedema (HACE), and the genetics, molecular mechanisms, and physiology that underpin them. We also present the vasogenic and cytotoxic bases for HACE and explore venous hypertension as a possible contributory factor. Although the factors that control susceptibility to HACE are poorly understood, the effects of exposure to altitude (and thus hypobaric hypoxia) might provide a reproducible model for the study of cerebral cellular hypoxia in healthy individuals. The effects of hypobaric hypoxia might also provide new insights into the understanding of hypoxia in the clinical setting. PMID:19161909

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

    DEFF Research Database (Denmark)

    Højlund Rasmussen, J; Mantoni, T; Belhage, B; Pott, F C

    2007-01-01

    Continuous positive airway pressure (CPAP) is a treatment modality for pulmonary oxygenation difficulties. CPAP impairs venous return to the heart and, in turn, affects cerebral blood flow (CBF) and augments cerebral blood volume (CBV). We considered that during CPAP, elevation of the upper body...... in 11 healthy subjects during CPAP at different body positions (15 degrees head-down tilt, supine, 15 degrees, 30 degrees and 45 degrees upper body elevation). In the supine position, 10 cmH(2)O of CPAP reduced MCA V(mean) by 9 +/- 3% and increased cHbT by 4 +/- 2 micromol/L (mean +/- SEM); (P <0.......05). In the head-down position, CPAP increased cHbT to 13 +/- 2 micromol/L but left MCA V(mean) unchanged. Upper body elevation by 15 degrees attenuated the CPAP associated reduction in MCA V(mean) (-7 +/- 2%), while cHbT returned to baseline (1 +/- 2 micromol/L). With larger elevation of the upper body...

  8. Cerebral blood flow and metabolism analysis in parkinsonian disorders; Pathologie extrapyramidale. Apport de l'imagerie de perfusion et du metabolisme (TEP, TEM)

    Energy Technology Data Exchange (ETDEWEB)

    Defebvre, L. [Hopital Roger Salengro, Service de Neurologie, 59 - Lille (France)

    1999-12-01

    Main metabolic and hemodynamic abnormalities detected by single photon emission computerized tomography and positron emission tomography in extra-pyramidal disorders are reported. In the first stage of Parkinson's disease, cortical metabolism and perfusion can be in normal range or moderately and uniformly reduced. A significant decrease may appear with the disease evolution. Marked abnormalities are observed in parkinsonian patients with dementia (subcortical dementia), involving especially the frontal cortex. A marked diffuse cortical hypo-metabolism (temporal, parietal, occipital and frontal cortex) may suggest the diagnosis of dementia with Lewy bodies, especially in case of fluctuating cognitive decline with recurrent visual hallucinations. In progressive supra-nuclear palsy, a frontal cortex hypo-metabolism is reported precociously, preceding sometimes the cognitive impairment. Metabolic pattern find in multiple system atrophy reflects dysfunction of both nigrostriatal pathways and striatum, with a decrease glucose uptake in putamen and caudate nucleus which also involves cerebellum for the patients with cerebellar syndrome. In cortico-basal degeneration, asymmetric fronto-parietal and striatal hypo-metabolism observed in the controlateral hemisphere to the clinically most affected side, constitute the main characteristic well correlated with apraxia. (author)

  9. The new factors defining variability of circadian’s rhythms of intraocular and perfusion pressure of glaucoma patients

    OpenAIRE

    Baranova, N. A.; A. V. Kuroyedov; Yu. V. Ovchinnikov

    2016-01-01

    Currently, the most scientifically based local risk and progressive factors are elevated levels of intraocular pressure and its instability during the day, caused by local hydromechanical disturbances. However, the other factors affecting the circadian changes of intraocular pressure levels are still evaluated. It was found that light is one of the most important factors affecting the intensity of the cyclical fluctuations of various biological processes, including, and fluctuations of intrao...

  10. Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage. Laboratory investigation

    DEFF Research Database (Denmark)

    Ansar, Saema; Edvinsson, Lars

    2009-01-01

    OBJECT: Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the...

  11. CT angiography and perfusion imaging in patients with subarachnoid hemorrhage: correlation of vasospasm to perfusion abnormality

    International Nuclear Information System (INIS)

    We retrospectively evaluated computed tomography angiography (CTA) and perfusion imaging (CTP) of patients with aneurysmal subarachnoid hemorrhage (SAH) for any correlation between degree of vasospasm and perfusion deficit. Sequentially performed CTP and CTA of 41 patients at least at the third day of postbleeding were reviewed for vasospasm and perfusion deficit throughout the anterior and middle cerebral arteries and corresponding territories. Vasospasm was noted comparing the contralateral normal ones or extradural components of the vessel itself and graded to negative, mild, moderate, and severe as luminal narrowing none, <25%, between 25% and 50%, and ≥50%, respectively. CTP abnormality was noted using cerebral blood flow and volume and mean transit time maps. Of 41 patients, 20 had no vasospasm; 15 had mild to moderate and six had severe vasospasm. Three of 20 patients with no vasospasm (15%), four of 15 patients with mild to moderate vasospasm (26%), and five of six patients with severe vasospasm (83%) had perfusion abnormality. Perfusion abnormalities noted were ischemia, infarction, and hyperperfusion. Perfusion abnormality without vasospasm was observed in the watershed areas and adjacent to sulcal clots. In SAH patients, if there is a macrovascular vasospasm with luminal narrowing ≥50%, there is a high likelihood (83%) of perfusion abnormality in the territory of the vasospastic vessel. There may also be perfusion abnormality without macrovascular vasospasm in the watershed areas or in the vicinity of sulcal clots. (orig.)

  12. Cerebral hemodynamics in patients with obstructive sleep apnea syndrome monitored with near-infrared spectroscopy (NIRS) during positive airways pressure (CPAP) therapy: a pilot study

    Science.gov (United States)

    Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Fritschi, Ursula; Lehner, Isabella; Qi, Ming; Khatami, Ramin

    2014-03-01

    In obstructive sleep apnea syndrome (OSA) the periodic reduction or cessation of breathing due to narrowing or occlusion of the upper airway during sleep leads to daytime symptoms and increased cardiovascular risk, including stroke. The higher risk of stroke is related to the impairment in cerebral vascular autoregulation. Continuous positive airways pressure (CPAP) therapy at night is the most effective treatment for OSA. However, there is no suitable bedside monitoring method evaluating the treatment efficacy of CPAP therapy, especially to monitor the recovery of cerebral hemodynamics. NIRS is ideally suited for non-invasive monitoring the cerebral hemodynamics during sleep. In this study, we will for first time assess dynamic changes of cerebral hemodynamics during nocturnal CPAP therapy in 3 patients with OSA using NIRS. We found periodic oscillations in HbO2, HHb, tissue oxygenation index (TOI) and blood volume associated with periodic apnea events without CPAP in all OSA patients. These oscillations were gradually attenuated and finally eliminated with the stepwise increments of CPAP pressures. The oscillations were totally eliminated in blood volume earlier than in other hemodynamic parameters. These results suggested that 1) the cerebral hemodynamic oscillations induced by OSA events can effectively be attenuated by CPAP therapy, and 2) blood flow and blood volume recovered first during CPAP therapy, followed by the recovery of oxygen consumption. Our study suggested that NIRS is a useful tool to evaluate the efficacy of CPAP therapy in patients with OSA bedside and in real time.

  13. The effect of S. pneumoniae bacteremia on cerebral blood flow autoregulation in rats

    DEFF Research Database (Denmark)

    Pedersen, Michael; Brandt, Christian T.; Knudsen, Gitte Moos;

    2008-01-01

    during incremental reductions in cerebral perfusion pressure (CPP) by controlled hemorrhage. Autoregulation was preserved in all rats without meningitis (groups A and E) and was lost in 24 of 25 meningitis rats (groups B, C, and D) (P<0.01). In group A, the lower limit was higher than that of group E (P......<0.05). The slope of the CBF/CPP regression line differed between the meningitis groups (P<0.001), being steeper for group B than groups C and D, with no difference between these two groups. The results suggest that pneumococcal bacteremia in rats triggers cerebral vasodilation, which right shifts...

  14. Semi-automatic quantification of regional cerebral perfusion in primary degenerative dementia using 99mTc-HMPAO and single photon emission tomography

    International Nuclear Information System (INIS)

    A new semi-automatic method for quantifying regional cerebral uptake of 99mTc-HMPAO was used to assess single photon emission tomograms from 5 normal subjects, 14 patients with Alzheimer's disease, 14 patients with dementia of frontal lobe type and 4 patients with dementia with motor neurone disease. Uptake in both posterior cortical regions, although not in other regions, was significantly lower (P<0.05) in Alzheimer's disease than in normal controls. Conversely in both dementia of frontal lobe type and dementia with motor neurone disease, uptake was significantly reduced (P<0.05) compared with controls in all anterior cortical regions but not in posterior regions. Numerical findings in each disease mirrored the pattern of reduced tracer uptake previously reported by visual assessment. Nine patients were re-examined after an interval of at least 1 year. Comparison of follow-up scans with original images showed significant decreases in mid-anterior, left anterior and left posterior cortical uptake (P<0.01) in patients with Alzheimer's disease and in left middle, left posterior and right posterior cortical uptake (P<0.01) in patients with dementia of frontal lobe type. The method of quantification may be a useful adjunct to the visual assessment of single photon emission tomograms. (orig.)

  15. Differences in respiratory pressure and pulmonary function among children with spastic diplegic and hemiplegic cerebral palsy in comparison with normal controls

    OpenAIRE

    Kwon, Yong Hyun; Lee, Hye Young

    2015-01-01

    [Purpose] The purpose of this study was to determine differences in respiratory pressure and pulmonary function among children with spastic diplegic and hemiplegic cerebral palsy (CP) in comparison with children with normal development. [Subjects and Methods] Fourteen children with spastic diplegic CP, 11 children with hemiplegic CP, and 14 children with normal development were recruited. Respiratory pressure was measured and the pulmonary function test (PFT) was performed to evaluate the str...

  16. Acute cerebral vascular accident associated with hyperperfusion

    International Nuclear Information System (INIS)

    Cerebral radionuclide angiography can demonstrate decreased or normal radioactivity in the affected region during the arterial phase in patients who have sustained a cerebral vascular accident and thus enhances the diagnostic specificity of the static brain image. In an occasional patient, however, a seemingly paradoxical pattern of regional hyperperfusion with a return to normal or subnormal perfusion following the acute phase has been observed. This phenomenon, called luxury perfusion, has been defined using intra-arterial 133Xe for semiquantitative cerebral blood flow measurements and should be kept in mind as a potentially misleading cerebral imaging pattern

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-06-01

    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/sub 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.

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

    International Nuclear Information System (INIS)

    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 PCO2 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

  19. Assessment of cerebral perfusion with single-photon emission tomography in normal subjects and in patients with Alzheimer's disease: effects of region of interest selection

    International Nuclear Information System (INIS)

    We compared three different ROIs in a SPET study with 60 controls and in 48 patients with probable Alzheimer's disease diagnosed according to the NINCDS-ADRDA criteria. Regional cerebral blood flow (rCBF) was assessed with SPET using technetium-99m d,l-hexamethylpropylene amine oxime (99mTc-HMPAO), normalized to the mean activity in a cerebellar reference slice. The three different ROIs were: a multi-slice and a single-slice ROI with reference to the normal brain anatomy (using an anatomical atlas), and a rectangular (2x4 pixels) ROI in the frontal, temporal, temporoparietal and occipital cortices. No differences were observed for the means of rCBF values between the single-slice and multi-slice ROI's with reference to the normal anatomy, but some variability was present for individual comparisons. In contrast, significantly higher mean rCBF values were obtained with the single-slice rectangular ROIs in all four regions for both patients and controls and considerable variability was shown for individual subjects. After analysis with multivariate logistic regression and receiver operator characteristic curves, the ability of SPET to discriminate between controls and Alzheimer patients was similar in the three methods for mild and moderate Alzheimer patients (Global Deterioration Scale = GDS of 3 and 4). However, with increasing dementia severity (GDS>4) the rectangular ROIs showed lower ability to discriminate between groups compared to the single-slice and multi-slice anatomically defined ROIs. This study suggests that results of rCBF assessment with SPET using 99mTc-HMPAO in patients with severe Alzheimer's disease are influenced by the shape and size of the ROI. (orig.)

  20. Measurement of temporal regional cerebral perfusion with single-photon emission tomography predicts rate of decline in language function and survival in early Alzheimer's disease

    International Nuclear Information System (INIS)

    We determined the relationship between regional cerebral blood flow (rCBF) measured with single-photon emission tomography (SPET) and decline in cognitive function and survival in Alzheimer's disease. In a prospective follow-up study, 69 consecutively referred patients with early probable Alzheimer's disease (NINCDS/ADRDA criteria) underwent SPET performed at the time of initial diagnosis using technetium-99m-labelled hexamethylpropylene amine oxime. Neuropsychological function was assessed at baseline and after 6 months and survival data were available on all patients, extending to 5.5 years of follow-up. Lower left temporal (P<0.01) and lower left parietal (P<0.01) rCBF were statistically significantly related to decline in language function after 6 months. The association between left temporal rCBF and survival was also statistically significant (P<0.05) using Cox proportional hazards regression analysis. Performing analysis with quartiles of the distribution, we found a threshold effect for low left temporal rCBF (rCBF<73.7%, P<0.01) and high risk of mortality. In this lowest quartile, median survival time was 2.7 years (follow-up to 5.2 years), compared with 4.4 years in the other quartiles (follow-up to 5.5 years). Kaplan-Meier survival curves showed statistically significant (P<0.05, log rank test) survival curves for the lowest versus other quartiles of left temporal rCBF. All results were unaffected by adjustment for age, sex, dementia severity, duration of symptoms, education and ratings of local cortical atrophy. We conclude that left temporal rCBF predicts decline in language function and survival in patients with early probable Alzheimer's disease, with a threshold effect of low rCBF and high risk of mortality. (orig.)

  1. Measurement of temporal regional cerebral perfusion with single-photon emission tomography predicts rate of decline in language function and survival in early Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Claus, J.J.; Walstra, G.J.M.; Hijdra, A.; Gool, W.A. van [Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Royen, E.A. van [Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam (Netherlands); Verbeeten, B. Jr. [Department of Radiology, Academic Medical Center, University of Amsterdam (Netherlands)

    1999-03-01

    We determined the relationship between regional cerebral blood flow (rCBF) measured with single-photon emission tomography (SPET) and decline in cognitive function and survival in Alzheimer`s disease. In a prospective follow-up study, 69 consecutively referred patients with early probable Alzheimer`s disease (NINCDS/ADRDA criteria) underwent SPET performed at the time of initial diagnosis using technetium-99m-labelled hexamethylpropylene amine oxime. Neuropsychological function was assessed at baseline and after 6 months and survival data were available on all patients, extending to 5.5 years of follow-up. Lower left temporal (P<0.01) and lower left parietal (P<0.01) rCBF were statistically significantly related to decline in language function after 6 months. The association between left temporal rCBF and survival was also statistically significant (P<0.05) using Cox proportional hazards regression analysis. Performing analysis with quartiles of the distribution, we found a threshold effect for low left temporal rCBF (rCBF<73.7%, P<0.01) and high risk of mortality. In this lowest quartile, median survival time was 2.7 years (follow-up to 5.2 years), compared with 4.4 years in the other quartiles (follow-up to 5.5 years). Kaplan-Meier survival curves showed statistically significant (P<0.05, log rank test) survival curves for the lowest versus other quartiles of left temporal rCBF. All results were unaffected by adjustment for age, sex, dementia severity, duration of symptoms, education and ratings of local cortical atrophy. We conclude that left temporal rCBF predicts decline in language function and survival in patients with early probable Alzheimer`s disease, with a threshold effect of low rCBF and high risk of mortality. (orig.) With 3 figs., 3 tabs., 44 refs.

  2. The new factors defining variability of circadian’s rhythms of intraocular and perfusion pressure of glaucoma patients

    Directory of Open Access Journals (Sweden)

    N. A. Baranova

    2016-01-01

    Full Text Available Currently, the most scientifically based local risk and progressive factors are elevated levels of intraocular pressure and its instability during the day, caused by local hydromechanical disturbances. However, the other factors affecting the circadian changes of intraocular pressure levels are still evaluated. It was found that light is one of the most important factors affecting the intensity of the cyclical fluctuations of various biological processes, including, and fluctuations of intraocular pressure. At the same time, glaucoma can lead to a variety of sleep disorders, due to a mismatch between cycles «sleep-wake». One if this reason is the death of retinal ganglion cells and their axons. Such damage indirectly lead to a decrease in production of the pigment melanopsin, which is located in the retina. It is not involved in the visual process, but ensures the implementation of circadian rhythms «sleep-wake» and mediated suppression of epiphyseal melatonin. Most likely, melatonin plays a protective role in the occurrence and progression of glaucoma, protecting retinal cells against free radicals and has a direct impact on the intraocular pressure level. Several studies have shown that the circadian change in intraocular pressure levels, and in particular, its substantial reduction, is influenced by melatonin. In this regard, glaucoma is a disease in which the death of retinal cells, including producing melanopsin, a unique opportunity to study violations of cyclic rhythms. Melatonin acts on such established risk factors and progression of glaucoma as hypertension and diabetes. There are published results of the use of melatonin agonists in the experiment and clinical practice. So, in addition to local and systemic hypotensive action, normalizes sleep patients. Data about the melatonin’s effects on the direct and indirect reduction of intraocular pressure, neuroprotective effects and reducing symptoms of depression can

  3. TLR4/NF-κB通路在深低温停循环逆行脑灌注技术脑保护机制中作用的研究%The role of TLR4/NF-κB pathway in cerebral protective effect of retrograde cerebral perfusion during deep ;hypothermic circulatory arrest

    Institute of Scientific and Technical Information of China (English)

    梁孟亚; 唐志贤; 陈光献; 荣健; 戴刚; 吴钟凯

    2013-01-01

    目的:研究TLR4/NF-κB通路是否参与深低温停循环逆行脑灌注的脑保护机制。方法五指山小型猪共10头,随机分成单纯深低温停循环组(DHCA组,n=5)与深低温停循环逆行脑灌注组(RCP组,n=5)。建立体外循环后,DHCA组降温至18℃后停循环40 min,RCP组停循环后经上腔静脉以10 ml/kg流量逆行脑灌注40 min。定期抽血检测血清IL-6水平。复灌180 min后处死动物取脑皮质组织行HE染色, Western blotting检测脑皮质TLR4,NF-κB/p65蛋白表达。结果脑皮质HE染色显示DHCA组较RCP组有更多炎症细胞浸润。在复灌60 min,复灌120 min及复灌180 min三个时点RCP的IL-6水平均显著低于DHCA组(t=7.314,P<0.01;t=5.172,P<0.01;t=4.676,P<0.01)。复灌180 min后RCP组脑皮质中TLR4水平明显低于DHCA组(t=10.212,P<0.001)。复灌180 min后RCP组脑皮质中NF-κB/p65水平明显低于DHCA组(t=3.344,P=0.011)。结论 RCP通过抑制TLR4/NF-κB信号通路而发挥抗炎作用,这可能是RCP脑保护作用的机制之一。%Objective To investigate whether TLR4/NF-κB Pathway is involved in cerebral protective effect of retrograde cerebral perfusion(RCP) during deep hypothermic circulatory arrest (DHCA). Methods Ten piglets of either sex (weigh 7.5-17.4 kg) were randomly assigned to 40 min of circulatory arrest (CA) at 18 ℃without cerebral perfusion (DHCA group, n=5) or RCP (RCP group, n=5). Blood samples were collected for assessment of serum IL-6 levels. After 3 h of reperfusion, cortical tissue was harvested for HE staining, western blotting of TLR4 and NF-κB/p65 expression. Results More severe inflammatory response was observed in brain tissue of DHCA group than RCP group. Serum IL-6 levels were significantly higher in the DHCA group than in RCP groups at 60 min, 120 min and 180 min after reperfusion (t=7.314, P<0.01; t=5.172,P<0.01; t=4.676, P<0.01 respectively). After 40 min of CA

  4. INTRACRANIAL PRESSURE MONITORING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Ida Bagus Adi Kayana

    2013-03-01

    Full Text Available Head injury is the most significant cause of increased morbidity and mortality. An estimated 1.4 million head injuries occur each year, with and more than 1.1 million come to the Emergency Unit. On each patient head injury, an increase in intracranial pressure (ICP related to poor outcomes and aggressive therapy to increased ICP can improve the outcomes. ICP monitoring is the most widely used because of the prevention and control of ICP as well as maintain the pressure increase perfusion of cerebral (Cerebral Perfusion Pressure/CPP is the basic purpose of handling head injury. There are two methods of monitoring ICP that is an invasive methods (directly and non-invasive techniques (indirectly. The method commonly used, namely intraventricular and intraparenkimal (microtransducer sensor because it is more accurate but keep attention to the existence of the risk of bleeding and infection resulting from installation. Monitoring of ICT can determine the actions that avoid further brain injury, which can be lethal and irreversibel.

  5. 脑灌注异常与冠状动脉旁路移植术后认知功能障碍的关系%Impaired cerebral perfusion as an independent risk factor for cognitive dysfunction after coronary artery bypass grafting

    Institute of Scientific and Technical Information of China (English)

    李俊玉; 毕齐

    2013-01-01

    目的:研究非体外循环下冠状动脉旁路移植术(off-pump coronary artery bypass grafting,OPCABG)术前脑灌注异常与术后认知功能障碍(postoperative cognitive dysfunction,POCD)的关系.方法:选择择期行OPCABG的患者364例,术前用320排动态容积CT评估患者是否存在脑灌注异常,将患者分为脑灌注正常组与脑灌注异常组.术前及术后7d采用简明精神状态量表(mini mental state examination,MMSE)及蒙特利尔认知评估量表(montreal cognitive assessment,MoCA)评估患者认知功能,判断患者术后是否发生了POCD,比较脑灌注正常组与脑灌注异常组POCD的发生率有无差别.结果:术前有76例(20.8%)的患者存在脑灌注异常,脑灌注异常组POCD发生率明显高于无脑灌注异常组(26.3%vs.9.7%,P<O.001).各脑灌注参数中,术前颞叶最大峰值时间(time-to-peak,TTP)对POCD的预测作用最强,曲线下面积为(0.664,95% CI:0.577 ~0.752,P<0.001).结论:术前脑灌注异常是OPCABG后POCD发生的危险因素.各脑灌注参数中,TTP对POCD的预测作用最强.%Objective:To analyze the relationship between impaired cerebral perfusion and the incidence of postoperative cognitive dysfunction (POCD) after off-pump coronary artery bypass gratting (OPCABG).Methods:This study included 364 cases undergoing OPCABG.Before surgery,the 320 row dynamic volume CT was used to determine if the cerebral perfusion is impaired.Each patient was evaluated with Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) 24 hours before and 7 days after surgery.The incidence of POCD was compared between the patients with impaired cerebral perfusion and those without impaired cerebral perfusion.Results:76 patients (20.8%) were found to have impaired cerebral perfusion and they had a higher rate of POCD when compared with the counterparts (26.3% vs.9.7%,P <0.001).The temporal lobe time-to-peak (TTP) was a better predictor of the occurrence of

  6. Functional Cluster Analysis of CT Perfusion Maps: A New Tool for Diagnosis of Acute Stroke?

    OpenAIRE

    Baumgartner, Christian; Gautsch, Kurt; Böhm, Christian; Felber, Stephan

    2005-01-01

    CT perfusion imaging constitutes an important contribution to the early diagnosis of acute stroke. Cerebral blood flow (CBF), cerebral blood volume (CBV) and time-to-peak (TTP) maps are used to estimate the severity of cerebral damage after acute ischemia. We introduce functional cluster analysis as a new tool to evaluate CT perfusion in order to identify normal brain, ischemic tissue and large vessels. CBF, CBV and TTP maps represent the basis for cluster analysis applying a partitioning (k-...

  7. Impaired autoregulation of cerebral blood flow in long-term type I (insulin-dependent) diabetic patients with nephropathy and retinopathy

    DEFF Research Database (Denmark)

    Kastrup, J; Rørsgaard, S; Parving, H H;

    1986-01-01

    Autoregulation of cerebral blood flow, i.e., the maintenance of cerebral blood flow within narrow limits during changes in arterial perfusion pressure, was studied in nine healthy control subjects and in 12 long-term Type I (insulin-dependent) diabetic patients with clinical microangiopathy....... Cerebral blood flow was measured by the intravenous 133Xenon method. Mean arterial blood pressure was elevated approximately 30 mmHg by intravenous infusion of angiotensin amide II and lowered about 10 mmHg by intravenous infusion of trimethaphan camsylate. In the control subjects the flow/pressure curve...... was horizontal indicating perfect autoregulation. In the diabetic patients the flow/pressure curve showed a significant slope with a 1.9% change in CBF per 10 mmHg change in mean arterial blood pressure as compared to a slope value of -0.4% in the control subjects (P less than 0.05). Our results...

  8. Comparison of the Effects of Dorzolamide/Timolol Fixed Combination versus Latanoprost on Intraocular Pressure and Ocular Perfusion Pressure in Patients with Normal-Tension Glaucoma: A Randomized, Crossover Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Na Young Lee

    Full Text Available To assess the noninferiority of a dorzolamide-timolol fixed combination (DTFC versus latanoprost in terms of intraocular pressure (IOP and to compare blood pressure (BP, ocular perfusion pressure (OPP and diastolic ocular perfusion pressure (DOPP between the latanoprost and DTFC groups in patients with normal-tension glaucoma (NTG.Prospective, interventional, randomized, single-blinded, crossover design study. Patients with newly diagnosed NTG that had not been treated with a glaucoma medication in the most recent 2 months were recruited. In total, 44 patients with NTG were randomly allocated to one of two groups. Patients in group A were treated with DTFC, lubricant, and latanoprost for 4 weeks each, whereas patients in group B were treated with latanoprost, lubricant, and DTFC for 4 weeks each. Patients were examined on day 1 (without medication, week 4 (under medication, week 8 (without medication, and week 12 (under medication. At weeks 4 and 12, diurnal IOP, systolic and diastolic BP, and OPP were measured at 8:00 AM, 10:00 AM, 12:00 PM, 4:00 PM, and 8:00 PM.Baseline demographic characteristics showed no difference in terms of age, sex, central corneal thickness, spherical equivalent, or stage of glaucoma between the groups. The between-group difference was -0.19 ± 0.18 mmHg (mean ± SE, upper bound of one-sided 95% CI, 0.12. Diurnal IOP showed no difference between the groups with an average IOP reduction of 13.1% using latanoprost and 12.3% using DTFC. Diurnal systolic and diastolic BP were lower in the DTFC group than the latanoprost group; however, the difference between the groups was not statistically significant. Diurnal OPP and DOPP also showed no statistically significant difference between the groups.IOP lowering efficacy of DTFC was noninferior to that of latanoprost in newly diagnosed NTG patients. There was no difference in BP, OPP, or DOPP between the latanoprost and DTFC groups. This prospective, randomized, single

  9. Brain perfusion CT in acute stroke: current status

    International Nuclear Information System (INIS)

    Dynamic perfusion CT has become a widely accepted imaging modality for the diagnostic workup of acute stroke patients. Although compared with standard spiral CT the use of multislice CT has broadened the range from which perfusion data may be derived in a single scan run. The advent of multidetector row technology has not really overcome the limited 3D capability of this technique. Multidetector CT angiography (CTA) of the cerebral arteries may in part compensate for this by providing additional information about the cerebrovascular status. This article describes the basics of cerebral contrast bolus scanning with a special focus on optimization of contrast/noise in order to ensure high quality perfusion maps. Dedicated scan protocols including low tube voltage (80 kV) as well as the use of highly concentrated contrast media are amongst the requirements to achieve optimum contrast signal from the short bolus passage through the brain. Advanced pre and postprocessing algorithms may help reduce the noise level, which may become critical in unconscious stroke victims. Two theoretical concepts have been described for the calculation of tissue perfusion from contrast bolus studies, both of which can be equally employed for brain perfusion imaging. For each perfusion model there are some profound limitations regarding the validity of perfusion values derived from ischemic brain areas. This makes the use of absolute quantitative cerebral blood flow (CBF) values for the discrimination of the infarct core from periinfarct ischemia questionable. Multiparameter imaging using maps of CBF, cerebral blood volume (CBV), and a time parameter of the local bolus transit enables analyzing of the cerebral perfusion status in detail. Perfusion CT exceeds plain CT in depicting cerebral hypoperfusion at its earliest stage yielding a sensitivity of about 90% for the detection of embolic and hemodynamic lesions within cerebral hemispheres. Qualitative assessment of brain perfusion can be

  10. The clinical utility acetazolamide enhanced cerebral SPECT in dementia

    International Nuclear Information System (INIS)

    Full text: This case report examines a combined stress-rest cerebral perfusion scan to differentiate vascular from other non-vascular dementias. Cerebrovascular reserve can be assessed following the vasodilatory response to CO2, or acetazolamide (Diamox) when conventional resting tests fail to identify perfusion abnormalities. The patient was a 70-year-women with a 10-year history of dementing disease. A recent MRI examination raised the possibility of Binswanger's Disease (DBT). Previously normal pressure hydrocephalus has been diagnosed but the patient did not respond to a subsequent ventricular shunting procedure. A resting HMPAO Ceretec SPECT scan was performed on a Siemens Diacam after injection of 1 GBq of HMPAO. For the stress scan (separate day study), Diamox (1g) was injected, 20 minutes prior to tracer injection. Resting HMPAO images were abnormal with a severe reduction in perfusion to the temporo-parietal lobes bilaterally. The 'stress' Diamox SPECT images showed no significant change from the baseline study. The severe reduction in perfusion to both temporoparietal regions remained constant. DBT is a rare variant of multi-infarct dementia with a gradual progression of ischemic injury to the deep white matter of the cerebral cortex than either Alzheimer's of multi-infarct dementia, and this can be assessed indirectly utilising rCBF with Diamox which test cerebrovascular haemodynamic reserve. Ischaemic areas have already vasodilated in response to Ischemia, they have decreased perfusion reserve and therefore can not respond to pharmacologic stress. In this care the unaltered rCBF before and after the administration of Diamox made a neurometabolic dysfunction the likely cause for the patient's symptoms and Alzheimer's Disease was diagnosed due to the constant decreased rCBF to the temporo-parietal regions. This case demonstrates the utility of Diamox rCBF in the differentiation between vascular and non-vascular dementia, as an adjunct to the clinical

  11. Electroacupuncture acutely improves cerebral blood flow and attenuates moderate ischemic injury via an endothelial mechanism in mice.

    Directory of Open Access Journals (Sweden)

    Ji Hyun Kim

    Full Text Available Electroacupuncture (EA is a novel therapy based on traditional acupuncture combined with modern eletrotherapy that is currently being investigated as a treatment for acute ischemic stroke. Here, we studied whether acute EA stimulation improves tissue and functional outcome following experimentally induced cerebral ischemia in mice. We hypothesized that endothelial nitric oxide synthase (eNOS-mediated perfusion augmentation was related to the beneficial effects of EA by interventions in acute ischemic injury. EA stimulation at Baihui (GV20 and Dazhui (GV14 increased cerebral perfusion in the cerebral cortex, which was suppressed in eNOS KO, but there was no mean arterial blood pressure (MABP response. The increased perfusion elicited by EA were completely abolished by a muscarinic acetylcholine receptor (mAChR blocker (atropine, but not a β-adrenergic receptor blocker (propranolol, an α-adrenergic receptor blocker (phentolamine, or a nicotinic acetylcholine receptor (nAChR blocker (mecamylamine. In addition, EA increased acetylcholine (ACh release and mAChR M3 expression in the cerebral cortex. Acute EA stimulation after occlusion significantly reduced infarct volume by 34.5% when compared to a control group of mice at 24 h after 60 min-middle cerebral artery occlusion (MCAO (moderate ischemic injury, but not 90-min MCAO (severe ischemic injury. Furthermore, the impact of EA on moderate ischemic injury was totally abolished in eNOS KO. Consistent with a smaller infarct size, acute EA stimulation led to prominent improvement of neurological function and vestibule-motor function. Our results suggest that acute EA stimulation after moderate focal cerebral ischemia, but not severe ischemia improves tissue and functional recovery and ACh/eNOS-mediated perfusion augmentation might be related to these beneficial effects of EA by interventions in acute ischemic injury.

  12. Correlation between hepatic CT perfusion imaging and portal vein pressure in normal Beagles%肝脏CT灌注成像与门静脉压力相关性的动物实验研究

    Institute of Scientific and Technical Information of China (English)

    林元为; 陈伟建; 张启瑜; 梁盼; 杨博洋

    2011-01-01

    目的:探讨正常比格犬门静脉压力与肝脏CT血流灌注参数的相关性.方法:采用螺旋CT对24只犬行肝脏灌注成像扫描,去卷积法计算肝脏血流灌注参数,包括血流量(blood flow,BF)、血容量(blood volume,BV)、平均通过时间(mean transit time,MTT)、肝动脉分数(hepatic arterial fraction,HAF)、肝动脉灌注量(hepatic arterial perfusion,HAP)、门静脉灌注量(portal venous perfusion,PVP).扫描后3 d内开腹,采用玻璃水柱法测定门静脉压力.利用直线回归与相关分析门静脉压力与肝脏CT血流灌注参数的相关性.结果:(1)正常比格犬实测门静脉压力值为(13.57±1.15)cmH2O.(2)正常比格犬门静脉压力与BF、PVP呈负相关,与HAF呈正相关,其中以PVP相关性最显著(r=-0.764,P<0.05),两者关系的直线回归方程为Y=16.507-0.037X.结论:肝脏CT灌注成像为无创、有效监测门静脉压力提供了一种新途径.%Objective To evaluate the correlation between the parameters of spiral CT perfusion imaging and portal vein pressure in normal Beagles. Methods Twenty-four normal beagles were selected to receive hepatic spiral CT perfusion imaging. The parameters of hepatic perfusion , including blood flow (BF) , blood volume (BV) ,mean transit time ( MTT) , hepatic arterial fraction ( HAF) , hepatic arterial perfusion ( HAP) , and portal venous perfusion (PVP) , were calculated hy the method of deconvolution. The portal vein pressure was measured by glass column method in laparotomy surgery three days after CT imaging. Results Portal vein pressure of the beagles were ( 13.57 ± 1.15) cmH2O. Portal vein pressure was negatively correlated with the BF and PVP , but was positively correlated with HAF. PVP was the most significant parameter that correlated with portal vein pressure (r = -0.764,P<0.05) , and their linear regression equation was Y = 16.507-0.037X. Conclusion CT perfusion imaging is a new non-invasive and eff'ective method for assessing portal vein

  13. Monitoring of cerebral haemodynamics in newborn infants

    DEFF Research Database (Denmark)

    Liem, K Djien; Greisen, Gorm

    2010-01-01

    The most important cerebrovascular injuries in newborn infants, particularly in preterm infants, are cerebral haemorrhage and ischemic injury. The typical cerebral vascular anatomy and the disturbance of cerebral haemodynamics play important roles in the pathophysiology. The term 'cerebral...... haemodynamics' includes cerebral blood flow (CBF), cerebral blood flow velocity, and cerebral blood volume (CBV). Therapy aimed at changing vascular anatomy is not available. Therefore, prevention of disturbances in CBF and CBV is pivotal. However, continuous monitoring of CBF and CBV is still unavailable for....... Using it even without knowing the exact level of CBF and CBV, it is possible to aim to keep CBF and CBV stable. Futureresearch should focus on development of monitoring tools, gaining more insight in neonatal cerebral autoregulation, and demonstrating clinical benefits of a 'cerebral perfusion...

  14. Ipsilateral Cerebral and Contralateral Cerebellar Hyperperfusion in Patients with Unilateral Cerebral Infarction; SPM Analysis

    International Nuclear Information System (INIS)

    Cortical reorganization has an important role in the recovery of stroke. We analyzed the compensatory cerebral and cerebellar perfusion change in patients with unilateral cerebral infarction using statistical parametric mapping (SPM). Fifty seven 99mTc-Ethylene Cystein Diethylester (ECD) cerebral perfusion SPECT images of 57 patients (male/female=38/19, mean age=56±17 years) with unilateral cerebral infarction were evaluated retrospectively. Patients were divided into subgroups according to the location (left, right) and the onset (acute, chronic) of infarction. Each subgroup was compared with normal controls (male/female=11/1, mean age =36±10 years) in a voxel-by-voxel manner (two sample t-test, p99mTc-ECD SPECT, we observed ipsilateral cerebral and contralateral cerebeller hyperperfusion in patients with cerebral infarction. However, whether these findings are related to the recovery of cerebral functions should be further evaluated

  15. Cerebral vascular effects of loading dose of dexmedetomidine: A Transcranial Color Doppler study

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    Appavoo Arulvelan

    2016-01-01

    Full Text Available Background: Dexmedetomidine has been widely used in critical care settings because of its property of maintaining stable hemodynamics and inducing conscious sedation. The use of dexmedetomidine is in increasing trend particularly in patients with neurological disorders. Very few studies have focused on the cerebral hemodynamic effects of dexmedetomidine. This study is aimed to address this issue. Methods: Thirty patients without any intracranial pathology were included in this study. Middle cerebral artery flow velocity obtained from transcranial color Doppler was used to assess the cerebral hemodynamic indices. Mean flow velocity (mFV, pulsatility index (PI, cerebral vascular resistant index (CVRi, estimated cerebral perfusion pressure (eCPP, and zero flow pressure (ZFP were calculated bilaterally at baseline and after infusion of injection Dexmedetomidine 1 mcg/Kg over 10 min. Results: Twenty-six patients completed the study protocol. After administration of loading dose of dexmedetomidine, mFV and eCPP values were significantly decreased in both hemispheres (P < 0.05; PI, CVRi, and ZFP values showed significant increase (P < 0.05 after dexmedetomidine infusion. Conclusion: Increase in PI, CVRi, and ZFP suggests that there is a possibility of an increase in distal cerebral vascular resistance (CVR with loading dose of dexmedetomidine. Decrease in mFV and eCPP along with an increase in CVR may lead to a decrease in cerebral perfusion. This effect can be exaggerated in patients with preexisting neurological illness. Further studies are needed to evaluate the effect of dexmedetomidine on various other pathological conditions involving brain like traumatic brain injury and vascular malformations.

  16. A Case of Apoplexy Attack-Like Neuropathy due to Hereditary Neuropathy with Liability to Pressure Palsies in a Patient Diagnosed with Chronic Cerebral Infarction.

    Science.gov (United States)

    Hachisuka, Akiko; Matsushima, Yasuyuki; Hachisuka, Kenji; Saeki, Satoru

    2016-06-01

    Hereditary neuropathy with liability to pressure palsies is an inherited disease associated with the loss of a copy of the PMP22 gene. The condition leads to mononeuropathy due to compression and easy strangulation during daily life activities, resulting in sudden muscle weakness and sensory disturbance, and displaying symptoms similar to cerebrovascular diseases. We report the case of an 80-year-old man with left paralysis due to chronic cerebral infarction. His medical history indicated remarkable recovery from about 4 months after the onset of left hemiplegia with predominant involvement of the fingers. Despite subsequent recurrent monoplegia of the upper or lower limbs, brain magnetic resonance imaging consistently revealed only previous cerebral infarction in the right corona radiata without new lesions. Medical examination showed reduced deep tendon reflexes in his extremities on both the healthy and hemiplegic sides. Nerve conduction studies showed delayed conduction at the bilateral carpal and cubital tunnels and near the right caput fibulae. Genetic analysis revealed loss of a copy of the PMP22 gene. Thus, he was diagnosed with a cerebral infarction complicated by hereditary neuropathy with liability to pressure palsies. Stroke patients develop sudden muscle weakness and sensory disturbance. However, if such patients have no hyperactive deep tendon reflexes and show atypical recovery of paralysis that does not correspond to findings of imaging modalities, nerve conduction studies and genetic analysis may be necessary, considering the complication of hereditary neuropathy with liability to pressure palsies. PMID:27080157

  17. 停循环和局部脑灌在主动脉弓中断手术中的应用%The usefulness of deep hypothermic circulatory arrest and regional cerebral perfusion in interrupted aortic arch

    Institute of Scientific and Technical Information of China (English)

    郭铮; 王伟; 张蔚; 沈佳; 唐嘉忠; 朱德明

    2013-01-01

    Objective To evaluate the effects of deep hypothermic circulatory arrest (DHCA) and regional cerebral perfusion (RCP) in interrupted aortic arch (IAA) corrective surgery.Methods Thirty-one infants younger than 3-month-old with IAA were undergone corrective surgery with DHCA or RCP.The bypass time,aortic clamp time,DHCA or RCP time,hematocrit,ventilation time,ICU stay time and post-operative complications were recorded and compared between two groups.Results The bypass time,aortic clamp time were longer in RCP group,and the RCP time was longer than DHCA time.One postoperative death and two neurological complications took place in DHCA group,while no mortality and neurological complications in RCP group.There were no significant differences in mortality and morbidity between two groups.Conclusion Because complicated surgery is undergone in IAA corrective procedure,RCP technique is safer to protect the brain function.%目的 比较深低温停循环(DHCA)与局部低流量脑灌(RCP)在小儿主动脉弓中断(IAA)纠治手术中的应用效果.方法 总结31例3个月以下的IAA合并室间隔缺损、房间隔缺损的婴儿手术病例,分为DHCA和RCP两组不同的体外循环方式,对术中转流时间,阻断时间,红细胞比容,停循环或脑灌时间,呼吸机插管时间,ICU滞留时间,术后低心排出量,肾功能衰竭,肺部炎症,出凝血障碍,多器官功能障碍,神经系统并发症,院内死亡率等情况进行分析.结果 RCP组手术的体外循环时间,阻断时间及脑灌时间显著长于DHCA组.DHCA组患儿死亡1例,神经系统并发症2例,RCP组无死亡和神经系统并发症,但两组无统计学差异.结论 IAA手术需要较长时间在主动脉上进行操作,采用RCP技术可以更好的保护神经系统功能,减少并发症.

  18. The natural history of misery perfusion in positron emission tomography

    International Nuclear Information System (INIS)

    This report reviews the natural courses of misery perfusion in 5 patients with atherosclerotic cerebrovascular occlusion diseases. Cases 1 showed partial improvement and Case 2 showed deterioration of misery perfusion on positron emission tomography (PET). These 2 patients did not show any clinical changes during the follow-up periods. Case 3 showed remarkable improvement of misery perfusion during the 2-year follow-ups, but his neurological condition worsened. The EC-IC bypass improved both in PET and clinical symptoms. Case 4 had a stroke at the region of misery perfusion in PET. Case 5 had a lacunar infarction 2 years after the EC-IC bypass on the opposite side. PET taken one month before the stroke did not show any signs of hypoperfusion in the area of the lacunar infarction. Misery perfusion seems not to be a static but a dynamic condition that can develop into cerebral infarction by some hemodynamic stresses. Cerebral cortical or lobar infarction may occur in the region of severe misery perfusion. EC-IC bypass may prevent impending infarction of the cerebral cortex by improving the regional cerebral blood flow. However, EC-CI bypass will not prevent the lacunar infarction of the basal ganglia or internal capsule. (author)

  19. Perfusion CT in acute stroke; Stellenwert der CT-Perfusion fuer die Therapie des Schlaganfalls

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Bernd [Asklepios Klinik Altona (Germany). Radiologie und Neuroradiologie; Roether, Joachim [Asklepios Klinik Altona (Germany). Neurologische Abt.; Fiehler, Jens [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neuroradiologische Diagnostik und Intervention; Thomalla, Goetz [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neurologie, Kopf- und Neurozentrum

    2015-06-15

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  20. Caffeine induced changes in cerebral circulation

    International Nuclear Information System (INIS)

    While the caffeine induced cerebral vasoconstriction is well documented, the effects of oral ingestion of the drug in a dose range comparable to the quantities in which it is usually consumed and the intensity and duration of the associated reduction in cerebral circulation are unknown. Cerebral blood flow was measured via the 133Xenon inhalation technique before and thirty and ninety minutes after the oral administration of 250 mg of caffeine or a placebo, under double-blind conditions. Caffeine ingestion was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later. The placebo group showed no differences between the three sets of cerebral blood flow values

  1. The protocol of dose reduction in liver perfusion computed tomography

    International Nuclear Information System (INIS)

    Cerebral perfusion computed tomography (CT) has been widespread, but abdominal perfusion CT has not been very popular because there has been a problem with regard to the limit of irradiation range and respiratory effects. Recently, it became easy to perform perfusion of abdominal organs because the use of multi detector row CT (MDCT) has been extensive. Along with it, the number of hospitals that perform liver perfusion CT has increased. However, patient dose of the liver perfusion CT is very high, making it very important to reduce patient dose. We created the virtual data that reduced the number of irradiation by partly reducing the data obtained on the liver perfusion CT. We compared the analysis results of all data with that of the partly reduced. It is possible to reduce the patient dose by reducing the number of irradiation because there was no significant difference in the analysis results. (author)

  2. Associations of sedentary behaviour, physical activity, blood pressure and anthropometric measures with cardiorespiratory fitness in children with cerebral palsy.

    Directory of Open Access Journals (Sweden)

    Jennifer M Ryan

    Full Text Available Children with cerebral palsy (CP have poor cardiorespiratory fitness in comparison to their peers with typical development, which may be due to low levels of physical activity. Poor cardiorespiratory fitness may contribute to increased cardiometabolic risk.The aim of this study was to determine the association between sedentary behaviour, physical activity and cardiorespiratory fitness in children with CP. An objective was to determine the association between cardiorespiratory fitness, anthropometric measures and blood pressure in children with CP.This study included 55 ambulatory children with CP [mean (SD age 11.3 (0.2 yr, range 6-17 yr; Gross Motor Function Classification System (GMFCS levels I and II]. Anthropometric measures (BMI, waist circumference and waist-height ratio and blood pressure were taken. Cardiorespiratory fitness was measured using a 10 m shuttle run test. Children were classified as low, middle and high fitness according to level achieved on the test using reference curves. Physical activity was measured by accelerometry over 7 days. In addition to total activity, time in sedentary behaviour and light, moderate, vigorous, and sustained moderate-to-vigorous activity (≥10 min bouts were calculated.Multiple regression analyses revealed that vigorous activity (β = 0.339, p<0.01, sustained moderate-to-vigorous activity (β = 0.250, p<0.05 and total activity (β = 0.238, p<0.05 were associated with level achieved on the shuttle run test after adjustment for age, sex and GMFCS level. Children with high fitness spent more time in vigorous activity than children with middle fitness (p<0.05. Shuttle run test level was negatively associated with BMI (r2 = -0.451, p<0.01, waist circumference (r2 = -0.560, p<0.001, waist-height ratio (r2 = -0.560, p<0.001 and systolic blood pressure (r2 = -0.306, p<0.05 after adjustment for age, sex and GMFCS level.Participation in physical activity, particularly at a vigorous intensity, is

  3. Acute stroke: the role of CT perfusion imaging

    International Nuclear Information System (INIS)

    Full text: The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the evaluation of acute stroke. This report illustrates the value of perfusion CT in the assessment of suspected acute stroke. Five cases are presented. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel by pixel analysis allowed generation of perfusion maps. Infarction is associated with reduced CBF and CBV whereas preserved CBV in the presence of reduced CBF implies intact autoregulation and hence potentially salvageable tissue (ie penumbra). The size of the perfusion defect indicates prognosis. In two cases, CT perfusion imaging usefully excluded acute stroke, including one patient in whom a low density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with nonhaemorrhage stroke in the presence of a normal conventional CT, to select those patients for whom thrombolysis is appropriate, and to provide an indication as to prognosis. Copyright (2002) Blackwell Science Pty Ltd

  4. Evaluation of cerebral hemodynamics by 123I-IMP in cerebral AVMs before and after operation by using SPECT

    International Nuclear Information System (INIS)

    To evaluate cerebral hemodynamics by N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) preoperative and postoperative (after 1 day, and after 7-10 days) regional cerebral blood flow scan, 6 arteriovenous malformations (AVMs) which performed total removal operations were studied by using a ring type SPECT 'HEADTOME'. We performed the dynamic scan just after the intravenous injection of 222 MBq (6 mCi) of 123I-IMP, then the static scan 20 minutes after the intravenous injection. In preoperative dynamic scans of all cases, only the first frame image showed the increased activity on the nidus probably because of the blood pool. Preoperative static scans of all cases showed the remarkable decreased activity on the nidus, and decreased activity surrounding the nidus probably because of the peripheral steal phenomenon. In postoperative scan of the next day, 4 out of 6 cases showed the transient decreased peripheral steal, particularly 2 out of those 4 cases showed the transient hyperperfusion probably because of the normal perfusion pressure break-through (NPPB). And, 2 out of 6 cases showed transient peripheral low perfusion on much larger area than those of the preoperative scans probably because of the focal brain damages and edemas. We conclude that 123I-IMP SPECT on AVM is very useful to decide the indication of the removal operation, and to estimate the postoperative risk, and to evaluate the preoperative and postoperative cerebral hemodynamic changes in the peripheral area of AVM. (author)

  5. Hemodynamic and metabolic effects of cerebral revascularization.

    Science.gov (United States)

    Leblanc, R; Tyler, J L; Mohr, G; Meyer, E; Diksic, M; Yamamoto, L; Taylor, L; Gauthier, S; Hakim, A

    1987-04-01

    Pre- and postoperative positron emission tomography (PET) was performed in six patients undergoing extracranial to intracranial bypass procedures for the treatment of symptomatic extracranial carotid occlusion. The six patients were all men, aged 52 to 68 years. Their symptoms included transient ischemic attacks (five cases), amaurosis fugax (two cases), and completed stroke with good recovery (one case). Positron emission tomography was performed within 4 weeks prior to surgery and between 3 to 6 months postoperatively, using oxygen-15-labeled CO, O2, and CO2 and fluorine-18-labeled fluorodeoxyglucose. Cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rates for oxygen and glucose (CMRO2 and CMRGlu), and the oxygen extraction fraction (OEF) were measured in both hemispheres. Preoperatively, compared to five elderly control subjects, patients had increased CBV, a decreased CBF/CBV ratio, and decreased CMRO2, indicating reduced cerebral perfusion pressure and depressed oxygen metabolism. The CBF was decreased in only one patient who had bilateral carotid occlusions; the OEF, CMRGlu, and CMRO2/CMRGlu and CMRGlu/CBF ratios were not significantly different from control measurements. All bypasses were patent and all patients were asymptomatic following surgery. Postoperative PET revealed decreased CBV and an increased CBF/CBV ratio, indicating improved hemodynamic function and oxygen hypometabolism. This was associated with increased CMRO2 in two patients in whom the postoperative OEF was also increased. The CMRGlu and CMRGlu/CBF ratio were increased in five patients. Changes in CBF and the CMRO2/CMRGlu ratio were variable. One patient with preoperative progressive mental deterioration, documented by serial neuropsychological testing and decreasing CBF and CMRO2, had improved postoperative CBF and CMRO2 concomitant with improved neuropsychological functioning. It is concluded that symptomatic carotid occlusion is associated with altered

  6. Impaired Cerebral Autoregulation during Head Up Tilt in Patients with Severe Brain Injury

    Science.gov (United States)

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira; Juhl, Carsten Bogh; Mehlsen, Jesper; Petersen, Tue Hvass

    2016-01-01

    Early mobilization is of importance for improving long-term outcome for patients after severe acquired brain injury. A limiting factor for early mobilization by head-up tilt is orthostatic intolerance. The purpose of the present study was to examine cerebral autoregulation in patients with severe acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography, middle cerebral artery velocity was evaluated by transcranial Doppler, and near-infrared spectroscopy determined frontal lobe oxygenation in the supine position and during head-up tilt. Cerebral autoregulation was evaluated as the mean flow index calculated as the ratio between middle cerebral artery mean velocity and estimated cerebral perfusion pressure. Patients with acquired brain injury presented an increase in mean flow index during head-up tilt indicating impaired autoregulation (P < 0.001). Spectral analysis of heart rate variability in the frequency domain revealed lower magnitudes of ~0.1 Hz spectral power in patients compared to healthy controls suggesting baroreflex dysfunction. In conclusion, patients with severe acquired brain injury and orthostatic intolerance during head-up tilt have impaired cerebral autoregulation more than one month after brain injury. PMID:27168188

  7. Simultaneous cerebral and spinal fluid pressure recordings in surgical indications of the Chiari malformation without myelodysplasia.

    Science.gov (United States)

    Häckel, M; Benes, V; Mohapl, M

    2001-09-01

    Patients with Chiari's malformation without myelodysplasia often suffer from another associated spinal cord lesion--syringomyelia. A condition entirely overriding the clinical picture, affecting adversely the results of surgery as well as the prognosis of this congenital developmental defect. Proceeding from the results of their surgical treatment of 40 patients with hindbrain malformation, the authors recommend, in accordance with the literature, a different approach to and classification of patients depending on the presence of syringomyelia (A/B classification; A: syringomyelia on MR--present, B: absent). The pathological development of the syrinx is caused by obstruction to the natural CSF circulation in the subarachnoid spaces of the craniocervical junction (Williams' dissociation theory). The authors are convinced that routine (static) imaging methods (CT, MR) cannot prove the presence or behaviour of a CSF block, and that they cannot help choose reliably the optimum type of treatment. In contrast, direct measurement (and monitoring) of CSF pressure in different compartments of the CSF pathways (intracranial/intraspinal compartment, i.e., in front of and beyond the suspected block) are a method which can help ascertain with precision the presence and behaviour of a CSF circulatory block, and which also provides dynamic information on such a block during the diurnal rhythm for a period of several days. The authors present the results of a prospective study of 25 patients with hindbrain malformation and describe a technique of parallel monitoring of the two CSF compartments using an adaptation of the Williams method, as well as two different types of dissociation tests designed to prove the presence of a CSF block. CSF flow obstruction was found in 11 patients, in 14 patients it could not be proved. In 8 out of 9 patients with a fully developed syrinx (group A) the block was found as expected. It was, however, diagnosed also in 3 patients until then without any

  8. Dynamic CT scan in cerebral infarction

    International Nuclear Information System (INIS)

    Forty-two dynamic CT studies were performed on 27 patients with cerebral infarction (11 to 75 years of age), and perfusion patterns of low density areas on plain CT were evaluated. The initial studies were performed 1.5 hours to 60 days after acute onset. The following results were obtained. 1) The perfusion pattern in the low density area on plain CT varies among patients at any periods after onset, ranging from absent perfusion pattern to hyperfusion pattern. No consisitent perfusion pattern was obtained at any given time after onset. 2) Repeat dynamic CT revealed that the perfusion pattern in the low density area changed with time variously. 3) The perfusion pattern or change of perfusion pattern did not correlate with outcome of the patient. 4) At an acute stage, when no abnormal findings were obtained on plain CT, dynamic CT revealed abnormal perfusion pattern, enabling early diagnosis of cerebral infarction and estimation of blood perfusion in the infarcted area. In determining the treatment for the cerebral infarction at an acute stage, it is important to know the condition of the blood perfusion in the infarcted area. For the patients in whom recanalization has already taken place, mannitol or steroid might be effective, providing protection against severe brain edema and hemorrhagic infarction. On the other hand, if recanalization has not taken place, revascularization therapy might be worth trying within 6 hours since the onset. It has been said that ischemic brain damage may not be reversed by the revascularization after 6 hours. Dynamic CT is safe, less invasive, convenient and very useful for early diagnosis of the cerebral infarction and determination of the treatment at the acute stage. (J.P.N.)

  9. The effect of an acute increase in central blood volume on the response of cerebral blood flow to acute hypotension.

    Science.gov (United States)

    Ogoh, Shigehiko; Hirasawa, Ai; Sugawara, Jun; Nakahara, Hidehiro; Ueda, Shinya; Shoemaker, J Kevin; Miyamoto, Tadayoshi

    2015-09-01

    The purpose of the present study was to examine whether the response of cerebral blood flow to an acute change in perfusion pressure is modified by an acute increase in central blood volume. Nine young, healthy subjects voluntarily participated in this study. To measure dynamic cerebral autoregulation during normocapnic and hypercapnic (5%) conditions, the change in middle cerebral artery mean blood flow velocity was analyzed during acute hypotension caused by two methods: 1) thigh-cuff occlusion release (without change in central blood volume); and 2) during the recovery phase immediately following release of lower body negative pressure (LBNP; -50 mmHg) that initiated an acute increase in central blood volume. In the thigh-cuff occlusion release protocol, as expected, hypercapnia decreased the rate of regulation, as an index of dynamic cerebral autoregulation (0.236 ± 0.018 and 0.167 ± 0.025 s(-1), P = 0.024). Compared with the cuff-occlusion release, the acute increase in central blood volume (relative to the LBNP condition) with LBNP release attenuated dynamic cerebral autoregulation (P = 0.009). Therefore, the hypercapnia-induced attenuation of dynamic cerebral autoregulation was not observed in the LBNP release protocol (P = 0.574). These findings suggest that an acute change in systemic blood distribution modifies dynamic cerebral autoregulation during acute hypotension. PMID:26159757

  10. The effect of CO sub 2 on pulmonary artery pressure (P sub pa ) over time in the isolated perfused rabbit lung

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, P.; Shayevitz, J. (Univ. of Michigan, Ann Arbor (United States))

    1991-03-11

    The isolated perfused rabbit lung model is used in studies of pulmonary hemodynamics, structure, and function under conditions closely resembling those which occur in living animals. The purpose of this study is to observe changes in P{sub pa} in response to differing concentrations of CO{sub 2} over time. After rapid exsanguination a tracheostomy was performed. Cannulas were secured in the main pulmonary artery and the left atrium. The lungs were perfused with Krebs-Henseleit buffer mixed with blood at a rate of 120 ml/min with recirculation. The temperature of the perfusate was maintained between 35 and 38C. The lungs were then ventilated with 5% CO{sub 2} in air with a tidal volume of 10 ml/kg at 20 breaths/min. CO{sub 2} was altered randomly by ventilating the lungs 2, 5 or 10% CO{sub 2} in air. Metabolic acidosis was corrected with NaHCO{sub 3}. In the first two hour period after lung perfusion was begun, the model was allowed to stabilize at each CO{sub 2} concentration, and pH, pCO{sub 2}, pO{sub 2}, and base excess were determined at each P{sub pa}. All measurements were repeated in the second period beginning two hours after lung perfusion was started. P{sub pa} was plotted against pH for each animal in both early and late phases, and simple regression analysis was performed. The slopes and the y intercepts for the data sets in both groups were compared using one factor ANOVA, and were found to be significantly different, implying a statistical difference between regression lines. In the early phase this model behaves like the in vivo lung, i.e. hypercarbia appears to increase, while hypocarbia decreases, P{sub pa}. During the late phase of lung perfusion the opposite occurs.

  11. Chest physiotherapy on intracranial pressure of critically ill patients admitted to the intensive care unit: a systematic review

    OpenAIRE

    Ferreira, Lucas Lima; Valenti, Vitor Engrácia; Vanderlei, Luiz Carlos Marques

    2013-01-01

    Objective To analyze the outcomes of increased or decreased intracranial pressure and/or the decrease in cerebral perfusion pressure resulting from respiratory physiotherapy on critically ill patients admitted to the intensive care unit. Methods Through a systematic review of the literature, clinical trials published between 2002 and 2012 were selected. The search involved the LILACS, SciELO, MedLine and PEDro databases using the keywords "physical therapy", "physiotherapy", "respiratory ther...

  12. Cerebral Aneurysms Fact Sheet

    Science.gov (United States)

    ... cerebral aneurysm from forming. People with a diagnosed brain aneurysm should carefully control high blood pressure, stop smoking, and avoid cocaine use or other stimulant drugs. They should also ...

  13. Magnetic resonance spectroscopy and imaging in cerebral ischemia

    International Nuclear Information System (INIS)

    In-vivo proton and phosphorus magnetic resonance spectroscopy was used to detect changes in cerebral metabolism during ischemia and other types of metabolic stress. Magnetic resonance imaging was performed in an animal model to observe morphological alterations during focal cerebral ischemia. Spectroscopy was performed in animal models with global ischemia, in volunteers during hyperventilation and pharmaco-logically altered cerebral perfusion, and in patients with acute and prolonged focal cerebral ischemia. (author). 396 refs.; 44 figs.; 14 tabs

  14. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  15. Obstructive hydrocephalus resulting from cerebral venous thrombosis

    OpenAIRE

    2011-01-01

    Cerebral venous thrombosis is a rare form of stroke in childhood. Increased intracranial pressure is a well-defined complication of cerebral venous thrombosis but obstructive hydrocephalus as a presentation finding of cerebral venous thrombosis is rarely described. A child case of cerebral sinus thrombosis presenting with obstructive hydrocephalus and management of clinical condition is presented with discussion of reported cases and treatment recommendations.

  16. 脉冲式及伪连续式动脉自旋标记技术静息态脑灌注对比研究%Comparative Study of Cerebral Perfusion by Using Pulsed and Pseudo Continuous Arterial Spin Labeling Techniques in Resting State

    Institute of Scientific and Technical Information of China (English)

    陈春晓; 郭超; 郑罡; 王利; 赵铁柱; 卢光明

    2013-01-01

    比较研究了脉冲式动脉自旋标记(pulsed arterial spin labeling,PASL)和伪连续式动脉自旋标记(pseudo continuous arterial spin labeling,pCASL)两种磁共振成像技术在静息态脑灌注中的应用.在静息态下,采用两种动脉自旋标记技术采集了10例健康志愿者的脑灌注数据,并计算脑血流量.两种技术的测量结果均显示,人脑默认网络中的楔前叶、角回、岛叶和后扣带回的相对脑血流量高于全脑平均灌注,而pCASL更敏感.在白质、额叶、顶叶、小脑和小脑蚓区域,pCASL和PASL测量得到的灌注值有显著性差异,除枕叶、小脑和小脑蚓外,PASL测量得到的灌注量小于pCASL.在全脑范围内,pCASL的信噪比明显高于PASL,且负灌注量很少.实验表明,pCASL可以提供比PASL更准确的测量结果.%The comparative study between pulsed arterial spin labeling (PASL) and pseudo continuous arterial spin labeling (pCASL) in resting cerebral perfusion were investigated. The PASL and pCASL data of 10 healthy subjects were acquired by a 3.0 T MR scanner during resting state, and the relative cerebral blood flows (rCBF) were then respectively quantified and analyzed. The results revealed that both techniques were able to detect the rCBF. CBFs in the precuneus, angular gyrus, insula, posterior cingulate cortex in default network were higher than the mean CBF in the whole brain, and pCASL was much more sensitive. Comparison with PASL sequence, CBFs obtained by the pCASL were significantly higher in white matter, frontal and parietal lobe, cerebellum and cerebellar vermis than that of PASL. Moreover, in the whole brain, higher SNR and less negative perfusion voxels were found in pCASL. The experimental results show that pCASL provides more accurate measurements than PASL in cerebral blood flow perfusion.

  17. Perfusion-weighted MR imaging in persistent hemiplegic migraine

    Energy Technology Data Exchange (ETDEWEB)

    Mourand, Isabelle; Menjot de Champfleur, Nicolas; Carra-Dalliere, Clarisse; Le Bars, Emmanuelle; Bonafe, Alain; Thouvenot, Eric [Hopital Gui de Chauliac, Service de Neuroradiologie, Montpellier (France); Roubertie, Agathe [Hopital Gui de Chauliac, Service de Neuropediatrie, Montpellier (France)

    2012-03-15

    Hemiplegic migraine is a rare type of migraine that has an aura characterized by the presence of motor weakness, which may occasionally last up to several days, and then resolve without sequela. Pathogenesis of migraine remains unclear and, recently, perfusion-weighted imaging (PWI) has provided a non-invasive method to study hemodynamic changes during acute attacks. Two female patients were admitted in our hospital suffering from prolonged hemiparesis. In both cases, they underwent MRI examination using a 1.5 T magnet including axial diffusion-weighted and perfusion sequences. From each perfusion MRI acquisition two regions of interest were delineated on each hemisphere and, the index of flow, cerebral blood volume, mean transit time, and time to peak were recorded and asymmetry indices from each perfusion parameter were calculated. Perfusion alterations were detected during the attacks. In one case, we observed, after 3 h of left hemiparesia, hypoperfusion of the right hemisphere. In the other case, who presented a familial hemiplegic migraine attack, on the third day of a persistent aura consisting of right hemiplegia and aphasia, PWI revealed hyperperfusion of the left hemisphere. Asymmetry indices for temporal parameters (mean transit time and time to peak) were the most sensitive. These findings resolved spontaneously after the attacks without any permanent sequel or signs of cerebral ischemia on follow-up MRI. PWI should be indicated for patients with migraine attacks accompanied by auras to assess the sequential changes in cerebral perfusion and to better understand its pathogenesis. (orig.)

  18. Perfusion-weighted MR imaging in persistent hemiplegic migraine

    International Nuclear Information System (INIS)

    Hemiplegic migraine is a rare type of migraine that has an aura characterized by the presence of motor weakness, which may occasionally last up to several days, and then resolve without sequela. Pathogenesis of migraine remains unclear and, recently, perfusion-weighted imaging (PWI) has provided a non-invasive method to study hemodynamic changes during acute attacks. Two female patients were admitted in our hospital suffering from prolonged hemiparesis. In both cases, they underwent MRI examination using a 1.5 T magnet including axial diffusion-weighted and perfusion sequences. From each perfusion MRI acquisition two regions of interest were delineated on each hemisphere and, the index of flow, cerebral blood volume, mean transit time, and time to peak were recorded and asymmetry indices from each perfusion parameter were calculated. Perfusion alterations were detected during the attacks. In one case, we observed, after 3 h of left hemiparesia, hypoperfusion of the right hemisphere. In the other case, who presented a familial hemiplegic migraine attack, on the third day of a persistent aura consisting of right hemiplegia and aphasia, PWI revealed hyperperfusion of the left hemisphere. Asymmetry indices for temporal parameters (mean transit time and time to peak) were the most sensitive. These findings resolved spontaneously after the attacks without any permanent sequel or signs of cerebral ischemia on follow-up MRI. PWI should be indicated for patients with migraine attacks accompanied by auras to assess the sequential changes in cerebral perfusion and to better understand its pathogenesis. (orig.)

  19. Propofol effect on cerebral oxygenation in children with congenital heart disease.

    Science.gov (United States)

    Fleck, Thilo; Schubert, Stephan; Ewert, Peter; Stiller, Brigitte; Nagdyman, Nicole; Berger, Felix

    2015-03-01

    Propofol is a short-acting, intravenously administered hypnotic agent which is used in procedural sedation in children. Propofol is known to decrease systemic vascular resistance, arterial blood pressure and can lead to desaturations and decreased systemic perfusion in children with cardiac shunting. This may result in a reduction in cerebral blood flow and oxygenation. Near-infrared spectroscopy (NIRS) can monitor cerebral tissue oxygenation in the frontal neocortex. The objective of our study was to measure the changes in cerebral oxygen and blood supply after Propofol infusion in children with congenital heart disease. Propofol infusion may reduce cerebral oxygenation in children with congenital heart disease. The study group consisted of 32 children (f:m = 18:14), with median age of 49 (5-112) months and median weight of 15 (5-34) kg. We performed NIRS derived continuous measurement of cerebral oxygenation and cardiac output using Electrical velocimetry for 5 min before and after sedation with Propofol (1-2 mg/kg i.v.) for cardiac catheterization. Simultaneously, non-invasive arterial blood pressure and transcutaneous oxygen saturation were measured. Propofol sedation led to a significant decrease in mean arterial pressure (79 ± 16 vs. 67 ± 12 mmHg) (p = 0.01) and cardiac index (3.2 ± 0.8 vs. 2.9 ± 0.6 ml/min/m(2)) (p = 0.03). In contrast, cerebral tissue oxygenation index, increased significantly from 57 ± 11 to 59 ± 10 % (p blood pressure. This may be caused by a decreased oxygen consumption of the sedated brain with intact cerebral auto-regulation. PMID:25311762

  20. Diagnosis of epidural hematoma by brain scan and perfusion study: case report

    International Nuclear Information System (INIS)

    By using the arterial and venous phases of an anterior cerebral perfusion study, which showed downward displacement of the sagittal sinus, and the finding of a rim on the delayed scans, the specific diagnosis of epidural hematoma was established

  1. Effects of the Oxygen-Carrying Solution OxyVita C on the Cerebral Microcirculation and Systemic Blood Pressures in Healthy Rats

    Directory of Open Access Journals (Sweden)

    Rania Abutarboush

    2014-11-01

    Full Text Available The use of hemoglobin-based oxygen carriers (HBOC as oxygen delivering therapies during hypoxic states has been hindered by vasoconstrictive side effects caused by depletion of nitric oxide (NO. OxyVita C is a promising oxygen-carrying solution that consists of a zero-linked hemoglobin polymer with a high molecular weight (~17 MDa. The large molecular weight is believed to prevent extravasation and limit NO scavenging and vasoconstriction. The aim of this study was to assess vasoactive effects of OxyVita C on systemic blood pressures and cerebral pial arteriole diameters. Anesthetized healthy rats received four intravenous (IV infusions of an increasing dose of OxyVita C (2, 25, 50, 100 mg/kg and hemodynamic parameters and pial arteriolar diameters were measured pre- and post-infusion. Normal saline was used as a volume-matched control. Systemic blood pressures increased (P ≤ 0.05 with increasing doses of OxyVita C, but not with saline. There was no vasoconstriction in small (<50 µm and medium-sized (50–100 µm pial arterioles in the OxyVita C group. In contrast, small and medium-sized pial arterioles vasoconstricted in the control group. Compared to saline, OxyVita C showed no cerebral vasoconstriction after any of the four doses evaluated in this rat model despite increases in blood pressure.

  2. Isolation and Cannulation of Cerebral Parenchymal Arterioles.

    Science.gov (United States)

    Pires, Paulo W; Dabertrand, Fabrice; Earley, Scott

    2016-01-01

    Intracerebral parenchymal arterioles (PAs), which include parenchymal arterioles, penetrating arterioles and pre-capillary arterioles, are high resistance blood vessels branching out from pial arteries and arterioles and diving into the brain parenchyma. Individual PA perfuse a discrete cylindrical territory of the parenchyma and the neurons contained within. These arterioles are a central player in the regulation of cerebral blood flow both globally (cerebrovascular autoregulation) and locally (functional hyperemia). PAs are part of the neurovascular unit, a structure that matches regional blood flow to metabolic activity within the brain and also includes neurons, interneurons, and astrocytes. Perfusion through PAs is directly linked to the activity of neurons in that particular territory and increases in neuronal metabolism lead to an augmentation in local perfusion caused by dilation of the feed PA. Regulation of PAs differs from that of better-characterized pial arteries. Pressure-induced vasoconstriction is greater in PAs and vasodilatory mechanisms vary. In addition, PAs do not receive extrinsic innervation from perivascular nerves - innervation is intrinsic and indirect in nature through contact with astrocytic endfeet. Thus, data regarding contractile regulation accumulated by studies using pial arteries does not directly translate to understanding PA function. Further, it remains undetermined how pathological states, such as hypertension and diabetes, affect PA structure and reactivity. This knowledge gap is in part a consequence of the technical difficulties pertaining to PA isolation and cannulation. In this manuscript we present a protocol for isolation and cannulation of rodent PAs. Further, we show examples of experiments that can be performed with these arterioles, including agonist-induced constriction and myogenic reactivity. Although the focus of this manuscript is on PA cannulation and pressure myography, isolated PAs can also be used for

  3. Modification of the cerebral perfusion during a chemotherapy by arabinoside cytosine (A.R.A.C.) among patients suffering of an acute myelo-blastic leukemia (A.M.L.)

    International Nuclear Information System (INIS)

    Cytosine arabinoside in high doses is a major treatment in acute myelo-blastic leukemia (A.M.L.). This treatment leads to neurological complications in 3-16% of cases, but the EEG, CT or MRI are normal.This prospective study examines brain perfusion in single photon emission tomography (SPECT) for patients receiving high dose arabinoside cytosine (H.D. A.R.A.C.). The SPECT of perfusion with hexamethyl propylene amine oxime (H.M.P.A.O.) for patients suffering of A.M.L. allowed to show a reduction of perfusion at the cerebellum level, of the occipito-parietal cortex and thalami, after conventional doses of A.R.A.C., while the patients had not any neurological accidents. (N.C.)

  4. Cerebral Hypoxia

    Science.gov (United States)

    ... Enhancing Diversity Find People About NINDS NINDS Cerebral Hypoxia Information Page Synonym(s): Hypoxia, Anoxia Table of Contents ( ... Trials Organizations Publicaciones en Español What is Cerebral Hypoxia? Cerebral hypoxia refers to a condition in which ...

  5. Diagnostic value of perfusion MRI in classifying stroke

    International Nuclear Information System (INIS)

    Our study was designed to determine whether supplementary information obtained with perfusion MRI can enhance accuracy. We used delayed perfusion, as represented by time to peak map on perfusion MRI, to classify strokes in 39 patients. Strokes were classified as hemodynamic if delayed perfusion extended to a whole territory of the occluded arterial trunk; as embolic if delayed perfusion was absent or restricted to infarcts; as arteriosclerotic if infarcts were small, multiple, and located mainly in the basal ganglias; or as unclassified if the pathophysiology was unclear. We compared these findings with vascular lesions on cerebral angiography, neurological signs, infarction on MRI, ischemia on xenon-enhanced CT (Xe/CT) and collateral pathway development. Delayed perfusion clearly indicated the area of arterial occlusion. Strokes were classified as hemodynamic in 13 patients, embolic in 14 patients, arteriosclerotic in 6 patients and unclassified in 6 patients. Hemodynamic infarcts were seen only in deep white-matter areas such as the centrum semiovale or corona radiata, whereas embolic infarcts were in the cortex, cortex and subjacent white matter, and lenticulo-striatum. Embolic and arteriosclerotic infarcts occurred even in hemo-dynamically compromized hemispheres. Our findings indicate that perfusion MRI, in association with adetailed analysis of T2-weighted MRI of cerebral infarcts in the axial and coronal planes, can accurately classify stroke as hemodynamic, embolic or arteriosclerotic. (author)

  6. Multi-delay arterial spin labeling perfusion MRI in moyamoya disease-comparison with CT perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui [Chinese Academy of Sciences, State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Beijing (China); University of Chinese Academy of Sciences, Graduate School, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Los Angeles, CA (United States); Yu, Songlin [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); University of California Los Angeles, Department of Neurology, Los Angeles (United States); Alger, Jeffry R.; Wang, Danny J.J. [University of California Los Angeles, Department of Neurology, Los Angeles (United States); UCLA-Beijing Joint Center for Advanced Brain Imaging, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Los Angeles, CA (United States); Zuo, Zhentao; Wang, Bo [Chinese Academy of Sciences, State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Beijing (China); Chen, Juan [Beijing Hospital, Department of Radiology, Beijing (China); Wang, Rong; Zhao, Jizong [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); An, Jing [Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen (China); Xue, Rong [Chinese Academy of Sciences, State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Los Angeles, CA (United States)

    2014-05-15

    To present a multi-delay pseudo-continuous ASL (pCASL) protocol that offers simultaneous measurements of cerebral blood flow (CBF) and arterial transit time (ATT), and to study correlations between multi-delay pCASL and CT perfusion in moyamoya disease. A 4 post-labeling delay (PLD) pCASL protocol was applied on 17 patients with moyamoya disease who also underwent CT perfusion imaging. ATT was estimated using the multi-delay protocol and included in the calculation of CBF. ASL and CT perfusion images were rated for lesion severity/conspicuity. Pearson correlation coefficients were calculated across voxels between the two modalities in grey and white matter of each subject respectively and between normalized mean values of ASL and CT perfusion measures in major vascular territories. Significant associations between ASL and CT perfusion were detected using subjective ratings, voxel-wise analysis in grey and white matter and region of interest (ROI)-based analysis of normalized mean perfusion. The correlation between ASL CBF and CT perfusion was improved using the multi-delay pCASL protocol compared to CBF acquired at a single PLD of 2 s (P < 0.05). There is a correlation between perfusion data from ASL and CT perfusion imaging in patients with moyamoya disease. Multi-delay ASL can improve CBF quantification, which could be a prognostic imaging biomarker in patients with moyamoya disease. (orig.)

  7. Multi-delay arterial spin labeling perfusion MRI in moyamoya disease-comparison with CT perfusion imaging

    International Nuclear Information System (INIS)

    To present a multi-delay pseudo-continuous ASL (pCASL) protocol that offers simultaneous measurements of cerebral blood flow (CBF) and arterial transit time (ATT), and to study correlations between multi-delay pCASL and CT perfusion in moyamoya disease. A 4 post-labeling delay (PLD) pCASL protocol was applied on 17 patients with moyamoya disease who also underwent CT perfusion imaging. ATT was estimated using the multi-delay protocol and included in the calculation of CBF. ASL and CT perfusion images were rated for lesion severity/conspicuity. Pearson correlation coefficients were calculated across voxels between the two modalities in grey and white matter of each subject respectively and between normalized mean values of ASL and CT perfusion measures in major vascular territories. Significant associations between ASL and CT perfusion were detected using subjective ratings, voxel-wise analysis in grey and white matter and region of interest (ROI)-based analysis of normalized mean perfusion. The correlation between ASL CBF and CT perfusion was improved using the multi-delay pCASL protocol compared to CBF acquired at a single PLD of 2 s (P < 0.05). There is a correlation between perfusion data from ASL and CT perfusion imaging in patients with moyamoya disease. Multi-delay ASL can improve CBF quantification, which could be a prognostic imaging biomarker in patients with moyamoya disease. (orig.)

  8. Ventilation-perfusion scintigraphy

    International Nuclear Information System (INIS)

    A historical review of different investigation methods measuring lung function (perfusion and gas exchange) is given. The principles and handling of some ventilation methods using radioxenon, radiokrypton or radiolabelled aerosols, and the injection method of xenon are explained. The clinical applicability of these studies is evaluated considering ventilation and perfusion lung defects and congestive heart failure. The combination of the three principal techniques (perfusion scintigraphy using MAA, ventilation scintigraphy using radioxenon or radiokrypton, perfusion and ventilation scientigraphy after injection of radioxenon) lead to typical patterns of differential diagnosis of perfusion defects. (TRV)

  9. The relation of consciousness level and cerebral blood flow in glioma and meningioma

    International Nuclear Information System (INIS)

    The relation between the consciousness level and cerebral blood flow (CBF) was analyzed in 17 cases of glioma and 6 cases of meningioma. CBF was in normal range in the alert groups of patients with glioma and meningioma. By contrast, CBF decreased generally not only in the affected side, but also in the non-affected side in the drowsy patient group with glioma. Widespread infiltration of glioma was seen in 4 cases of 6 drowsy cases. CBF increased after the partial resection of the tumor in 2 cases of glioma. Thus the disturbance of consciousness level was attributable to diffuse hypofunction accompanying the diffuse infiltration of glioma and the decrease of cerebral perfusion pressure caused by the increased intracranial pressure. (author)

  10. Impaired Cerebral Autoregulation during Head Up Tilt in Patients with Severe Brain Injury

    DEFF Research Database (Denmark)

    Riberholt, Christian Gunge; Olesen, Niels Damkjær; Thing, Mira;

    2016-01-01

    Early mobilization is of importance for improving long-term outcome for patients after severe acquired brain injury. A limiting factor for early mobilization by head-up tilt is orthostatic intolerance. The purpose of the present study was to examine cerebral autoregulation in patients with severe...... acquired brain injury and a low level of consciousness. Fourteen patients with severe acquired brain injury and orthostatic intolerance and fifteen healthy volunteers were enrolled. Blood pressure was evaluated by pulse contour analysis, heart rate and RR-intervals were determined by electrocardiography...... mean velocity and estimated cerebral perfusion pressure. Patients with acquired brain injury presented an increase in mean flow index during head-up tilt indicating impaired autoregulation (P < 0.001). Spectral analysis of heart rate variability in the frequency domain revealed lower magnitudes of ~0...

  11. Diffusion-weighted imaging in the diagnostic evaluation of the hydrocephalus in patients with acute or chronic increase in cerebral pressure

    International Nuclear Information System (INIS)

    Purpose: to investigate whether diffusion-weighted imaging (DWI) in magnetic resonance imaging (MRI) provides additional information about the periventricular white matter for the assessment of hydrocephalus. Materials and methods: sixteen MRI examinations (11 with acutely increased cerebral pressure, 5 without symptoms) on 15 patients with hydrocephalus (4 patients with communicating hydrocephalus and 11 patients with obstructive hydrocephalus) were analyzed. One symptomatic patient subsequently became asymptomatic. We investigated the ''apparent diffusion coefficient'' (ADC) in the subcortical and periventricular white matter. The ADCs of the study patients were compared with those of a healthy control group. Results: symptomatic patients with hydrocephalus, 6/11 showed periventricular edema and a significantly higher ADC values in the periventricular region than in the subcortical white matter. 5/11 symptomatic patients showed significantly higher ADC values even in the absence of periventricular interstitial edema (both groups contained patients with communicating and obstructive hydrocephalus). All 5 asymptomatic patients with hydrocephalus did not have a significantly higher ADC values in the periventricular region. Conclusion: in patients with hydrocephalus and acutely increased cerebral pressure, DWI showed a significantly higher ADC values in the periventricular region even without visible interstitial edema on conventional MRI sequences. (orig.)

  12. Modification of the cerebral perfusion during a chemotherapy by arabinoside cytosine (A.R.A.C.) among patients suffering of an acute myelo-blastic leukemia (A.M.L.); Modification de la perfusion cerebrale au cours d'une chimiotherapie par cytosine arabinoside (ARAC) chez les patients atteints d'une leucemie aigue myeloblastique (LAM)

    Energy Technology Data Exchange (ETDEWEB)

    Modzelewski, R.; Vera, P. [Universite de Medecine de Rouen, QUANT.I.F-LITIS EA4108, departement de medecine nucleaire, 76 (France); Lepretre, S.; Tilly, H. [Centre Henri-Becquerel, departement d' hematologie, 76 - Rouen (France); Martinaud, O.; Hannequin, D. [CHU de Rouen, departement de neurologie, 76 (France); Habert, M.O. [CHU de la Pitie-Salpetriere, departement de medecine nucleaire, 75 - Paris (France)

    2010-07-01

    Cytosine arabinoside in high doses is a major treatment in acute myelo-blastic leukemia (A.M.L.). This treatment leads to neurological complications in 3-16% of cases, but the EEG, CT or MRI are normal.This prospective study examines brain perfusion in single photon emission tomography (SPECT) for patients receiving high dose arabinoside cytosine (H.D. A.R.A.C.). The SPECT of perfusion with hexamethyl propylene amine oxime (H.M.P.A.O.) for patients suffering of A.M.L. allowed to show a reduction of perfusion at the cerebellum level, of the occipito-parietal cortex and thalami, after conventional doses of A.R.A.C., while the patients had not any neurological accidents. (N.C.)

  13. Diagnosis of hemodynamic compromise in patients with chronic cerebral ischemia

    International Nuclear Information System (INIS)

    Tests using 133Xe inhalation method and single photon emission computed tomography (SPECT) with acetazolamide (Diamox) were performed in 23 patients with chronic cerebral ischemia, before and after extracranial-intracranial bypass surgery or carotid-endarterectomy. All patients complained of TIA, RIND, or minor completed stroke. Cerebral angiography demonstrated severe stenosis or occlusion in the ipsilateral internal carotid artery or middle cerebral artery. Cerebral blood flow (CBF) was measured with 133Xe SPECT, and was measured 15 minutes after intravenous administration of 10-12 mg/kg Diamox, which is known as a cerebral vasodilatory agent (Diamox test). Our results revealed that all patients could be divided into four types according to their resting rCBF and Diamox reactivity. The patients who had normal resting rCBF and normal Diamox reactivity (type 1) were considered to have well-developed collateral circulation and normal cerebral perfusion pressure (CPP) in spite of severe occlusive lesions in the carotid system. Moderate vasodilation due to reduced CPP was considered to occur in patients who had normal resting rCBF and decreased Diamox reactivity (type 2). The resting rCBF remained unchanged, but Diamox reactivity improved to normal after surgery in the patients of type 2, which indicated the improvement of CPP and the resolution of the autoregulatory vasodilation. Maximum vasodilation or dysautoregulation was considered to occur due to the inadequate collateral flow and the severely reduced CPP in patients whose findings revealed decrease in the resting rCBF and impaired Diamox reactivity (type 3). Remarkable improvement was seen in both resting rCBF and Diamox reactivity after surgery in the patients of type 3. In the patients who had decreased resting rCBF and normal Diamox reactivity (type 4), the decreased resting rCBF was considered to result from the reduction in metabolic demand because of irreversible ischemic neuronal damage. (J.P.N.)

  14. Comparison of Tc-99m ECD brain SPECT between patients with delayed development and cerebral palsy

    International Nuclear Information System (INIS)

    Purpose: In previous study, thalamic or cerebellar hypoperfusion were reported in patients with cerebral palsy. This study was performed to evaluate cerebral perfusion abnormalities using Tc-99m ECD brain SPECT in patients with delayed motor development. Methods: Nineteen patients (9 boys, 10 girls, mean age 25.5 months) with delayed development underwent brain SPECT after injection of 185∼370 MBq of Tc-99m ECD. The imaging was obtained between 30 minutes and 1hr after injection. The patients were divided clinically as follows, patients with delayed development (n=5) and patients with cerebral palsy (n=14) who has delayed development and abnormal movement. The clinical subtypes of cerebral palsy were spastic quadriplegia (n=5), spastic diplegia (n=6) and spastic hemiplegia (n=3). In each group, decrease of cerebral perfusion was evaluated visually as mild, moderate and severe and quantitation of cerebral perfusion after Lassen's correction was also obtained. Results: SPECT findings showed normal or mildly decreased thalamic perfusion in patients with delayed development and severe decrease of thalamic or cerebellar perfusion in patients with spastic quadriplegia. In patients with spastic diplegia, mild decrease of perfusion was observed in thalamus. In quantified data, thalamic perfusion was lowest in patients with spastic quadriplegia and highest in patients with delayed development, but there were no statistically significant differences. Conclusion: Brain SPECT with Tc-99m ECD has a role in the detection of perfusion abnormalities in patients with delayed development and cerebral palsy

  15. A Lumped Parameter Method to Calculate the Effect of Internal Carotid Artery Occlusion on Anterior Cerebral Artery Pressure Waveform

    OpenAIRE

    Abdi, M.; Navidbakhsh, M.; Razmkon, A.

    2016-01-01

    Background and Objective Numerical modeling of biological structures would be very helpful tool to analyze hundreds of human body phenomena and also diseases diagnosis. One physiologic phenomenon is blood circulatory system and heart hemodynamic performance that can be simulated by utilizing lumped method. In this study, we can predict hemodynamic behavior of one artery of circulatory system (anterior cerebral artery) when disease such as internal carotid artery occlusion is occurred. Method ...

  16. Tuberculoma cerebral Cerebral tuberculoma

    OpenAIRE

    ELIZABETH CLARA BARROSO; TÂNIA REGINA BRÍGIDO DE OLIVEIRA; ANA MARIA DANTAS DO AMARAL; VALÉRIA GÓES FERREIRA PINHEIRO; ANA LÚCIA DE OLIVEIRA SOUSA

    2002-01-01

    Relata-se o caso de paciente com crises convulsivas de início recente. A tomografia computadorizada cerebral evidenciou imagem sugestiva de lesão expansiva metastática frontoparietal direita. A investigação de tumor primário ou outra doença foi negativa e o exame histopatológico do tecido cerebral diagnosticou tuberculoma. As convulsões foram controladas com a associação de hidantoína 300mg/dia ao esquema específico, utilizado por 18 meses. A tuberculose do sistema nervoso central representa ...

  17. Perfusion CT in childhood stroke—Initial observations and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Zebedin, D., E-mail: doris.zebedin@medunigraz.at [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria); Sorantin, E.; Riccabona, M. [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria)

    2013-07-15

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction.

  18. Perfusion CT in childhood stroke—Initial observations and review of the literature

    International Nuclear Information System (INIS)

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction

  19. Utility of the cerebral SPECT in schizophrenia

    International Nuclear Information System (INIS)

    Objective: To compare cortical and subcortical cerebral perfusion in schizophrenics patients with normal controls, and analyze the relation to clinical patterns and neuroleptic treatment. Method: 18 patients meeting DSM-IV criteria for schizophrenia under neuroleptic treatment (except 3 cases), evaluated with clinical scales (BPRS and PANSS). The control group included 5 subjects in good health. All subjects were studied with single photon emission computed tomography (SPECT) using technetium-99 etilencisteinato (99mTc-ECD) as a tracer. Region of interest (ROI) were defined in cerebral cortex and thalamus-basal ganglia areas. The cortical cerebral blood flow was measured with a quantitative analysis, expressed as a ratio of regional tracer uptake to occipital cortex uptake. In basal ganglia and thalamus, regional blood flow was evaluated with a semiquantitative methodology, defining categories. Results: Schizophrenics patients showed a significant reduction of perfusion on a left anterior frontal cortex ('hipofrontality') and global decrease of perfusion on left hemisphere. The interhemispheric (left/right) ratio of perfusion was incremented respect control group. In thalamic-basal ganglia complex, a significant hypoperfusion was found in neuroleptic-free patients and control group. On the other hand, neuroleptic-treated patients revealed normal or increased regional blood flow in thalamus and basal ganglia. Only the clinical item 'thought disorder' had significant high correlation with perfusion on left structures (left anterior frontal, left lateral frontal, left temporo-parietal); the other items correlated with right structures. Conclusions: The findings suggest a pattern o left cerebral hypoperfusion in patients with an incremented interhemispheric ratio of cerebral blood flow. The pivotal role of thalamic and basal ganglia areas in the pathophysiology of schizophrenia and neuroleptic action was reaffirmed; apparently, perfusion in thalamic-basal ganglia

  20. Cerebral angiography in leptomeningitis and cerebritis

    International Nuclear Information System (INIS)

    This is a report of the cerebral angiographic findings in cases of meningitis and cerebritis. Fifty-nine patients, 38 of whom were under 1 year of age, underwent cerebral angiography by means of femoral catheterization. All the patients had signs of increased intracranial pressure, seizures, focal cerebral signs, positive transillumination of the head, and or abnormal brain scan findings. A few patients who did not respond to systemic antibiotics as was expected were also evaluated by means of cerebral angiography. The following characteristic angiographic findings were observed in 18 cases of active meningitis: (1) A hasy appearance around the arteries (halo formation) between the late arterial and capillary phases. (2) Narrowing of the arteries in the basal cistern. This sometimes extended to the peripheral arteries. (3) Irregular caliber following the narrowing of arteries (in few cases). (4) Circulation time so slow that veins could be seen in the late arterial phase. (5) Halo formation around the anterior chroidal artery and the clear appearance of the choroid plexus in the venous phase (when the infectious process reached the choroid plexus). Cerebritis could be identified on the angiograms by two signs: (1) local swelling of the brain (mainly the temporal lobe) and (2) staining around the veins without any abnormal signs in the arterial phase (laminar staining). In conclusion, angiography is a meaningful test by which to determine the phase of meningitis and cerebritis. These two conditions should be treated based on valid information obtained by means of CSF examinations and neuroradiological tests, especially CT scan and cerebral angiography. (author)

  1. Cochlear perfusion with a viscous fluid.

    Science.gov (United States)

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

    The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and

  2. Resting brain perfusion and selected vascular risk factors in healthy elderly subjects

    DEFF Research Database (Denmark)

    Mølby Henriksen, Otto; Jensen, Lars T; Krabbe, Katja;

    2014-01-01

    with circulating homocysteine, but not with asymmetric dimethylarginine, dyslipidemia or the carotid intima-media thickness. The relative regional brain perfusion was associated with circulating homocysteine, with a relative parietal hypoperfusion and a frontal hyperperfusion. No effect on regional brain perfusion...... was observed for any of the other risk factors. A multiple regression model including homocysteine, caffeine, hematocrit and end-tidal PCO2, explained nearly half of the observed variability. CONCLUSION: Both intrinsic and extrinsic factors influenced global cerebral perfusion variation between subjects....... Further, the results suggest that the inverse relation between homocysteine and brain perfusion is owing to other mechanisms, than reflected by asymmetric dimethylarginine, and that homocysteine may be a marker of cerebral perfusion in aging brains....

  3. Myogenic and metabolic feedback in cerebral autoregulation: Putative involvement of arachidonic acid-dependent pathways.

    Science.gov (United States)

    Berg, Ronan M G

    2016-07-01

    The present paper presents a mechanistic model of cerebral autoregulation, in which the dual effects of the arachidonic acid metabolites 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) on vascular smooth muscle mediate the cerebrovascular adjustments to a change in cerebral perfusion pressure (CPP). 20-HETE signalling in vascular smooth muscle mediates myogenic feedback to changes in vessel wall stretch, which may be modulated by metabolic feedback through EETs released from astrocytes and endothelial cells in response to changes in brain tissue oxygen tension. The metabolic feedback pathway is much faster than 20-HETE-dependent myogenic feedback, and the former thus initiates the cerebral autoregulatory response, while myogenic feedback comprises a relatively slower mechanism that functions to set the basal cerebrovascular tone. Therefore, assessments of dynamic cerebral autoregulation, which may provide information on the response time of the cerebrovasculature, may specifically be used to yield information on metabolic feedback mechanisms, while data based on assessments of static cerebral autoregulation represent the integrated functionality of myogenic and metabolic feedback. PMID:27241246

  4. Displaying perfusion MRI images as color intensity projections

    CERN Document Server

    Hoefnagels, Friso; Sanchez, Ester; Lagerwaard, Frank J

    2007-01-01

    Dynamic susceptibility-weighted contrast-enhanced (DSC) MRI or perfusion-MRI plays an important role in the non-invasive assessment of tumor vascularity. However, the large number of images provided by the method makes display and interpretation of the results challenging. Current practice is to display the perfusion information as relative cerebral blood volume maps (rCBV). Color intensity projections (CIPs) provides a simple, intuitive display of the perfusion-MRI data so that regional perfusion characteristics are intrinsically integrated into the anatomy structure the T2 images. The ease of use and quick calculation time of CIPs should allow it to be easily integrated into current analysis and interpretation pipelines.

  5. Ipsilateral Cerebral and Contralateral Cerebellar Hyperperfusion in Patients with Unilateral Cerebral Infarction; SPM Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sun Pyo; Yoon, Joon Kee; Choi, Bong Hoi; Joo, In Soo; Yoon, Seok Nam [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2008-10-15

    Cortical reorganization has an important role in the recovery of stroke. We analyzed the compensatory cerebral and cerebellar perfusion change in patients with unilateral cerebral infarction using statistical parametric mapping (SPM). Fifty seven {sup 99m}Tc-Ethylene Cystein Diethylester (ECD) cerebral perfusion SPECT images of 57 patients (male/female=38/19, mean age=56{+-}17 years) with unilateral cerebral infarction were evaluated retrospectively. Patients were divided into subgroups according to the location (left, right) and the onset (acute, chronic) of infarction. Each subgroup was compared with normal controls (male/female=11/1, mean age =36{+-}10 years) in a voxel-by-voxel manner (two sample t-test, p<0.001) using SPM. All 4 subgroups showed hyperperfusion in the ipsilateral cerebral cortex, but not in the contralateral cerebral cortex. Chronic left and right infarction groups revealed hyperperfusion in the ipsilateral primary sensorimotor cortex, meanwhile, acute subgroups did not. Contralateral cerebellar hyperperfusion was also demonstrated in the chronic left infarction group. Using {sup 99m}Tc-ECD SPECT, we observed ipsilateral cerebral and contralateral cerebeller hyperperfusion in patients with cerebral infarction. However, whether these findings are related to the recovery of cerebral functions should be further evaluated.

  6. Diagnosis of epidural hematoma by brain scan and perfusion study: case report. [/sup 99m/Tc tracer techniques

    Energy Technology Data Exchange (ETDEWEB)

    Buozas, D.J.; Barrett, I.R.; Mishkin, F.S.

    1976-11-01

    By using the arterial and venous phases of an anterior cerebral perfusion study, which showed downward displacement of the sagittal sinus, and the finding of a rim on the delayed scans, the specific diagnosis of epidural hematoma was established.

  7. Acute ischemic stroke with tandem/terminal ICA occlusion - CT perfusion based case selection for mechanical recanalization

    Directory of Open Access Journals (Sweden)

    Rajsrinivas Parthasarathy

    2015-01-01

    Conclusion: The cerebral blood volume (CBV core estimation reliably predicted the final infarct volume. The key reasons for the significantly better outcomes seen in our cohort were the stringent perfusion imaging-based patient selection and the rapid reperfusion.

  8. Cerebrovascular hemodynamics in patients with cerebral arteriosclerosis

    Institute of Scientific and Technical Information of China (English)

    Jianbo Yang; Changcong Cui; Chengbin Wu

    2011-01-01

    The present study observed hemodynamic changes in 26 patients with cerebral arteriosclerosis using a cerebral circulation dynamics detector and transcranial Doppler.In patients with cerebral arteriosclerosis the blood supply and flow rate in the bilateral carotid arteries and the blood flow rate in the anterior cerebral and middle cerebral arteries were similar to normal controls, but the cerebral vascular resistance, critical pressure and pulsatility index were increased, and cerebral arterial elasticity and cerebral blood flow autoregulation were decreased.Compared with the lesioned hemisphere of patients with cerebral infarction, the total blood supply and blood flow rate of patients with cerebral arteriosclerosis were higher.Compared with normal subjects, patients with cerebral arteriosclerosis exhibited cognitive disturbances, mainly in short-term memory, attention, abstract capability, and spatial and executive dysfunction.Results showed that cerebral arteriosclerosis does not directly affect the blood supply of a cerebral hemisphere, but affects cognitive function.The increased cerebral vascular resistance and reduced autoregulation of cerebral blood vessels may be important hemodynamic mechanisms of arteriosclerosis-induced cerebral infarction.

  9. Cerebral Palsy

    Science.gov (United States)

    Cerebral palsy is a group of disorders that affect a person's ability to move and to maintain balance ... do not get worse over time. People with cerebral palsy may have difficulty walking. They may also have ...

  10. Simultaneous monitoring of static and dynamic intracranial pressure parameters from two separate sensors in patients with cerebral bleeds: comparison of findings

    Directory of Open Access Journals (Sweden)

    Eide Per

    2012-09-01

    Full Text Available Abstract Background We recently reported that in an experimental setting the zero pressure level of solid intracranial pressure (ICP sensors can be altered by electrostatics discharges. Changes in the zero pressure level would alter the ICP level (mean ICP; whether spontaneous changes in mean ICP happen in clinical settings is not known. This can be addressed by comparing the ICP parameters level and waveform of simultaneous ICP signals. To this end, we retrieved our recordings in patients with cerebral bleeds wherein the ICP had been recorded simultaneously from two different sensors. Materials and Methods: During a time period of 10 years, 17 patients with cerebral bleeds were monitored with two ICP sensors simultaneously; sensor 1 was always a solid sensor while Sensor 2 was a solid -, a fluid - or an air-pouch sensor. The simultaneous signals were analyzed with automatic identification of the cardiac induced ICP waves. The output was determined in consecutive 6-s time windows, both with regard to the static parameter mean ICP and the dynamic parameters (mean wave amplitude, MWA, and mean wave rise time, MWRT. Differences in mean ICP, MWA and MWRT between the two sensors were determined. Transfer functions between the sensors were determined to evaluate how sensors reproduce the ICP waveform. Results Comparing findings in two solid sensors disclosed major differences in mean ICP in 2 of 5 patients (40%, despite marginal differences in MWA, MWRT, and linear phase magnitude and phase. Qualitative assessment of trend plots of mean ICP and MWA revealed shifts and drifts of mean ICP in the clinical setting. The transfer function analysis comparing the solid sensor with either the fluid or air-pouch sensors revealed more variable transfer function magnitude and greater differences in the ICP waveform derived indices. Conclusions Simultaneous monitoring of ICP using two solid sensors may show marked differences in static ICP but close to identity

  11. Laser doppler perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 {mu}m. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs.

  12. Laser doppler perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Waardell, K.

    1992-11-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 {mu}m. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs.