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Sample records for cerebral perfusion pressure

  1. Enhanced Visualization of Optimal Cerebral Perfusion Pressure Over Time to Support Clinical Decision Making

    NARCIS (Netherlands)

    Aries, Marcel J H; Wesselink, Robin; Elting, Jan Willem J; Donnelly, Joseph; Czosnyka, Marek; Ercole, Ari; Maurits, Natasha M; Smielewski, Peter

    2016-01-01

    OBJECTIVE: Cerebrovascular reactivity can provide a continuously updated individualized target for management of cerebral perfusion pressure, termed optimal cerebral perfusion pressure. The objective of this project was to find a way of improving the optimal cerebral perfusion pressure methodology b

  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. Clinical and Physiological Events That Contribute to the Success Rate of Finding "Optimal" Cerebral Perfusion Pressure in Severe Brain Trauma Patients

    NARCIS (Netherlands)

    Weersink, Corien S. A.; Aries, Marcel J. H.; Dias, Celeste; Liu, Mary X.; Kolias, Angelos G.; Donnelly, Joseph; Czosnyka, Marek; van Dijk, J. Marc C.; Regtien, Joost; Menon, David K.; Hutchinson, Peter J.; Smielewski, Peter

    2015-01-01

    Objective: Recently, a concept of an individually targeted level of cerebral perfusion pressure that aims to restore impaired cerebral vasoreactivity has been advocated after traumatic brain injury. The relationship between cerebral perfusion pressure and pressure reactivity index normally is suppos

  5. Carbon dioxide induced changes in cerebral blood flow and flow velocity: Role of cerebrovascular resistance and effective cerebral perfusion pressure

    NARCIS (Netherlands)

    F. Grüne (Frank); S. Kazmaier (Stephan); R.J. Stolker (Robert J.); G.H. Visser (Gerhard Henk); A. Weyland (Andreas)

    2015-01-01

    textabstractIn addition to cerebrovascular resistance (CVR) zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe) and the resistance area product (RAP) are supplemental determinants of cerebral blood flow (CBF). Until now, the interrelationship of PaCO2 -induced changes in CBF, CVR,

  6. 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

  7. Carbon dioxide induced changes in cerebral blood flow and flow velocity: role of cerebrovascular resistance and effective cerebral perfusion pressure.

    Science.gov (United States)

    Grüne, Frank; Kazmaier, Stephan; Stolker, Robert J; Visser, Gerhard H; Weyland, Andreas

    2015-09-01

    In addition to cerebrovascular resistance (CVR) zero flow pressure (ZFP), effective cerebral perfusion pressure (CPPe) and the resistance area product (RAP) are supplemental determinants of cerebral blood flow (CBF). Until now, the interrelationship of PaCO2-induced changes in CBF, CVR, CPPe, ZFP, and RAP is not fully understood. In a controlled crossover trial, we investigated 10 anesthetized patients aiming at PaCO2 levels of 30, 37, 43, and 50 mm Hg. Cerebral blood flow was measured with a modified Kety-Schmidt-technique. Zero flow pressure and RAP was estimated by linear regression analysis of pressure-flow velocity relationships of the middle cerebral artery. Effective cerebral perfusion pressure was calculated as the difference between mean arterial pressure and ZFP, CVR as the ratio CPPe/CBF. Statistical analysis was performed by one-way RM-ANOVA. When comparing hypocapnia with hypercapnia, CBF showed a significant exponential reduction by 55% and mean VMCA by 41%. Effective cerebral perfusion pressure linearly decreased by 17% while ZFP increased from 14 to 29 mm Hg. Cerebrovascular resistance increased by 96% and RAP by 39%; despite these concordant changes in mean CVR and Doppler-derived RAP correlation between these variables was weak (r=0.43). In conclusion, under general anesthesia hypocapnia-induced reduction in CBF is caused by both an increase in CVR and a decrease in CPPe, as a consequence of an increase in ZFP.

  8. The effects of propofol or sevoflurane on the estimated cerebral perfusion pressure and zero flow pressure.

    Science.gov (United States)

    Marval, Paul D; Perrin, Mandy E; Hancock, Sally M; Mahajan, Ravi P

    2005-03-01

    The zero flow pressure (ZFP) is the pressure at which blood flow ceases through a vascular bed. Using transcranial Doppler ultrasonography, we investigated the effects of propofol or sevoflurane on the estimated cerebral perfusion pressure (eCPP) and ZFP in the cerebral circulation. Twenty-three healthy patients undergoing nonneurosurgical procedures under general anesthesia were studied. After induction of anesthesia using propofol, the anesthesia was maintained with either propofol infusion (n = 13) or sevoflurane (n = 10). Middle cerebral artery flow velocity, noninvasive arterial blood pressure, and end-tidal carbon dioxide partial pressure were recorded awake as a baseline, and during steady-state anesthesia at normocapnia (baseline end-tidal carbon dioxide partial pressure) and hypocapnia (1 kPa below baseline). The eCPP and ZFP were calculated using an established formula. The mean arterial blood pressure decreased in both groups. The eCPP decreased significantly in the propofol group (median, from 58 to 41 mm Hg) but not in the sevoflurane group (from 60 to 62 mm Hg). Correspondingly, ZFP increased significantly in the propofol group (from 25 to 33 mm Hg) and it decreased significantly in the sevoflurane group (from 27 to 7 mm Hg). Hypocapnia did not change eCPP or ZFP in the propofol group, but it significantly decreased eCPP and increased ZFP in the sevoflurane group. PMID:15728076

  9. 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....

  10. Intracranial pressure and cerebral perfusion pressure monitoring in non-TBI patients: special considerations.

    Science.gov (United States)

    Helbok, Raimund; Olson, DaiWai M; Le Roux, Peter D; Vespa, Paul

    2014-12-01

    The effect of intracranial pressure (ICP) and the role of ICP monitoring are best studied in traumatic brain injury (TBI). However, a variety of acute neurologic illnesses e.g., subarachnoid hemorrhage, intracerebral hemorrhage, ischemic stroke, meningitis/encephalitis, and select metabolic disorders, e.g., liver failure and malignant, brain tumors can affect ICP. The purpose of this paper is to review the literature about ICP monitoring in conditions other than TBI and to provide recommendations how the technique may be used in patient management. A PubMed search between 1980 and September 2013 identified 989 articles; 225 of which were reviewed in detail. The technique used to monitor ICP in non-TBI conditions is similar to that used in TBI; however, indications for ICP monitoring often are intertwined with the presence of obstructive hydrocephalus and hence the use of ventricular catheters is more frequent. Increased ICP can adversely affect outcome, particularly when it fails to respond to treatment. However, patients with elevated ICP can still have favorable outcomes. Although the influence of ICP-based care on outcome in non-TBI conditions appears less robust than in TBI, monitoring ICP and cerebral perfusion pressure can play a role in guiding therapy in select patients.

  11. 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

  12. Intrathoracic Pressure Regulation Improves Cerebral Perfusion and Cerebral Blood Flow in a Porcine Model of Brain Injury.

    Science.gov (United States)

    Metzger, Anja; Rees, Jennifer; Kwon, Young; Matsuura, Timothy; McKnite, Scott; Lurie, Keith G

    2015-08-01

    Brain injury is a leading cause of death and disability in children and adults in their most productive years. Use of intrathoracic pressure regulation (IPR) to generate negative intrathoracic pressure during the expiratory phase of positive pressure ventilation improves mean arterial pressure and 24-h survival in porcine models of hemorrhagic shock and cardiac arrest and has been demonstrated to decrease intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in these models. Application of IPR for 240 min in a porcine model of intracranial hypertension (ICH) will increase CPP when compared with controls. Twenty-three female pigs were subjected to focal brain injury by insertion of an epidural Foley catheter inflated with 3 mL of saline. Animals were randomized to treatment for 240 min with IPR set to a negative expiratory phase pressure of -12 cmH2O or no IPR therapy. Intracranial pressure, mean arterial pressure, CPP, and cerebral blood flow (CBF) were evaluated. Intrathoracic pressure regulation significantly improved mean CPP and CBF. Specifically, mean CPP after 90, 120, 180, and 240 min of IPR use was 43.7 ± 2.8 mmHg, 44.0 ± 2.7 mmHg, 44.5 ± 2.8 mmHg, and 43.1 ± 1.9 mmHg, respectively; a significant increase from ICH study baseline (39.5 ± 1.7 mmHg) compared with control animals in which mean CPP was 36.7 ± 1.4 mmHg (ICH study baseline) and then 35.9 ± 2.1 mmHg, 33.7 ± 2.8 mmHg, 33.9 ± 3.0 mmHg, and 36.0 ± 2.7 mmHg at 90, 120, 180, and 240 min, respectively (P blood flow, as measured by an invasive CBF probe, increased in the IPR group (34 ± 4 mL/100 g-min to 49 ± 7 mL/100 g-min at 90 min) but not in controls (27 ± 1 mL/100 g-min to 25 ± 5 mL/100 g-min at 90 min) (P = 0.01). Arterial pH remained unchanged during the entire period of IPR compared with baseline values and control values. In this anesthetized pig model of ICH, treatment with IPR significantly improved CPP and CBF. This therapy may be of clinical value by noninvasively

  13. 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....

  14. Sumatriptan and cerebral perfusion in healthy volunteers.

    Science.gov (United States)

    Scott, A K; Grimes, S; Ng, K; Critchley, M; Breckenridge, A M; Thomson, C; Pilgrim, A J

    1992-04-01

    1. The effect of sumatriptan on regional cerebral perfusion was studied in healthy volunteers. 2. Intravenous sumatriptan (2 mg) had no detectable effect on regional cerebral perfusion as measured using a SPECT system with 99technetiumm labelled hexemethylpropyleneamineoxime. 3. Sumatriptan had no effect on pulse, blood pressure or ECG indices. 4. All six volunteers experienced minor adverse effects during the intravenous infusion.

  15. Bernoulli's Principle Applied to Brain Fluids: Intracranial Pressure Does Not Drive Cerebral Perfusion or CSF Flow.

    Science.gov (United States)

    Schmidt, Eric; Ros, Maxime; Moyse, Emmanuel; Lorthois, Sylvie; Swider, Pascal

    2016-01-01

    In line with the first law of thermodynamics, Bernoulli's principle states that the total energy in a fluid is the same at all points. We applied Bernoulli's principle to understand the relationship between intracranial pressure (ICP) and intracranial fluids. We analyzed simple fluid physics along a tube to describe the interplay between pressure and velocity. Bernoulli's equation demonstrates that a fluid does not flow along a gradient of pressure or velocity; a fluid flows along a gradient of energy from a high-energy region to a low-energy region. A fluid can even flow against a pressure gradient or a velocity gradient. Pressure and velocity represent part of the total energy. Cerebral blood perfusion is not driven by pressure but by energy: the blood flows from high-energy to lower-energy regions. Hydrocephalus is related to increased cerebrospinal fluid (CSF) resistance (i.e., energy transfer) at various points. Identification of the energy transfer within the CSF circuit is important in understanding and treating CSF-related disorders. Bernoulli's principle is not an abstract concept far from clinical practice. We should be aware that pressure is easy to measure, but it does not induce resumption of fluid flow. Even at the bedside, energy is the key to understanding ICP and fluid dynamics. PMID:27165887

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

    NARCIS (Netherlands)

    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 i

  17. 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...

  18. Effect of propofol and thiopentone on intracranial pressure and cerebral perfusion pressure in patients undergoing elective craniotomy - a comparative study

    Directory of Open Access Journals (Sweden)

    Sankari Santra

    2007-01-01

    Full Text Available Advantages and disadvantages of newer agent like propofol need to be evaluated with time tested inducing drug - thiopentone in neuroanaesthesia. The aim of the study was to compare effects of propofol with thiopentone on intracranial pressure, cerebral perfusion pressure and haemodynamics during induction in neurosurgical pa-tients. Fifty adult patients of ASA grade I& II scheduled for elective craniotomy were randomly assigned to receive induction of anaesthesia with either propofol 1.5-2.5 mg.kg -1 i.v. (Group A, n=25 or thiopentone 4-5 mg.kg -1 , i.v. (Group B, n=25. Vecuronium bromide 0.1 mg.kg -1 i.v. was used as intubating muscle relaxant. Both groups received fentanyl 2 pg.kg -1 i.v., lidocaine(preservative free 1.5 mg.kg -1 i.v. and supplementary dose of same inducing agent before intubation. Changes in mean arterial pressure (MAP, cerebrospinal fluid pressure (CSFP, cerebral perfusion pressure (CPP and heart rate (HR were noted during induction and endotracheal intubation. On statistical analysis it was found that CSFP decreased significantly (P< 0.001 in both groups after induction but endotracheal intubation did not provoke any significant rise in CSFP. Maximum decrease of CSFP was 35.26% in Group A and 35.20% in Group B. Fall in MAP was more significant in Group A (P< 0.001, as a result CPP was significantly less in Group A than in Group B. The lowest mean CPP (71.12±5.86 mm Hg was observed 2 minutes after induction dose in Group A when maximum drop in MAP occurred. Heart rate did not change significantly in Group A but in Group B fluctuation of heart rate was more.

  19. Cerebral perfusion pressure and risk of brain hypoxia in severe head injury: a prospective observational study

    Science.gov (United States)

    Marín-Caballos, Antonio J; Murillo-Cabezas, Francisco; Cayuela-Domínguez, Aurelio; Domínguez-Roldán, Jose M; Rincón-Ferrari, M Dolores; Valencia-Anguita, Julio; Flores-Cordero, Juan M; Muñoz-Sánchez, M Angeles

    2005-01-01

    Introduction Higher and lower cerebral perfusion pressure (CPP) thresholds have been proposed to improve brain tissue oxygen pressure (PtiO2) and outcome. We study the distribution of hypoxic PtiO2 samples at different CPP thresholds, using prospective multimodality monitoring in patients with severe traumatic brain injury. Methods This is a prospective observational study of 22 severely head injured patients admitted to a neurosurgical critical care unit from whom multimodality data was collected during standard management directed at improving intracranial pressure, CPP and PtiO2. Local PtiO2 was continuously measured in uninjured areas and snapshot samples were collected hourly and analyzed in relation to simultaneous CPP. Other variables that influence tissue oxygen availability, mainly arterial oxygen saturation, end tidal carbon dioxide, body temperature and effective hemoglobin, were also monitored to keep them stable in order to avoid non-ischemic hypoxia. Results Our main results indicate that half of PtiO2 samples were at risk of hypoxia (defined by a PtiO2 equal to or less than 15 mmHg) when CPP was below 60 mmHg, and that this percentage decreased to 25% and 10% when CPP was between 60 and 70 mmHg and above 70 mmHg, respectively (p < 0.01). Conclusion Our study indicates that the risk of brain tissue hypoxia in severely head injured patients could be really high when CPP is below the normally recommended threshold of 60 mmHg, is still elevated when CPP is slightly over it, but decreases at CPP values above it. PMID:16356218

  20. 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

  1. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

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

    2014-01-01

    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 di...

  2. Perfusion Pressure Cerebral Infarct (PPCI) trial - the importance of mean arterial pressure during cardiopulmonary bypass to prevent cerebral complications after cardiac surgery: study protocol for a randomised controlled trial

    DEFF Research Database (Denmark)

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

    2016-01-01

    to be 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 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...

  3. Effects of Blood Pressure Fluctuations on Cerebral Perfusion after Ischemic Stroke%血压波动对脑梗死后脑灌注的影响

    Institute of Scientific and Technical Information of China (English)

    聂志余; 靳令经

    2011-01-01

    Cerebral infarction affects both cerebral autoregulation and cerebral perfusion. This review article summarizes the published evidence of cerebral autoregulation impairment and cerebral blood flow alteration after cerebral infarction, including cerebrovascular small vessel disease leading to an impairment of vasoreactivity, blood flow velocities and cerebral blood flow associated positively with systemic blood pressure, perfusion declined on the infarcted side and lower blood pressure resulting in hypoperfusion in distal area of the narrowing main cerebral artery. The question should be thought by physicians about what is the 'best blood pressure range' in patients with cerebral infarction and it will be benefit for optimal recovery.%本文主要从脑血管的自动调节与自动调节受损、脑小血管病变可导致脑血管反应性受损、脑梗死患者脑血流速度、脑血流量与血压的相关性,脑梗死侧大脑半球脑灌注降低、低血压对脑主要动脉狭窄者可导致狭窄远端脑组织局部低灌注等几个方面来讨论脑梗死后血压的变化对脑血流速度、脑血流量的影响.给临床医生提出一个思考问题,在脑梗死的急性期把血压控制在多少才是最合适的水平,对患者的功能恢复最有益.

  4. Cerebral perfusion SPECT in transient ischemic attack

    Energy Technology Data Exchange (ETDEWEB)

    You, D.-L. E-mail: dlyou@mail.kfcc.org.tw; Shieh, F.-Y.; Tzen, K.-Y.; Tsai, M.-F.; Kao, P.-F

    2000-04-01

    Purpose: The purpose of our study is to evaluate the efficacy of cerebral perfusion single photon emission computerized tomography (SPECT) in patients with transient ischemic attack (TIA). Methods: Thirty-seven patients with TIA were collected for study. All patients had transient focal neurological symptoms or signs with complete recovery within 24 h after onset. The patients underwent cerebral perfusion SPECT between 6 h and 11 days after onset, with 10 cases performed within 24 h (group A), nine cases performed between 1 and 3 days (group B), 11 cases performed between 3 and 5 days (group C), and seven cases performed after more than 5 days (group D). A semi-quantitative method was used for analyzing the SPECT data, and the difference ratios between lesion side and contralateral normal side were calculated on each pair of regions of interest. Results: In total, 78.4% (29/37) of patients had reduced perfusion in the cerebral cortical regions or deep nuclei, and the regions with reduced perfusion corresponded with clinical presentations of the patients. The abnormal rate with reduced perfusion was 90.0% in group A, 77.8% in group B, 72.7% in group C and 71.4% in group D. Cross cerebellar diaschisis (CCD) was present in seven patients, and all of the primary cerebral perfusion defects of these patients were located at the territory of left or right middle cerebral artery. Conclusion: Cerebral perfusion SPECT is a potential tool to detect cerebral perfusion defects and CCD in patients with TIA. Although the perfusion defect may persist more than 5 days after onset, we suggest cerebral perfusion SPECT should be performed as soon as possible.

  5. 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

  6. 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

  7. 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

  8. Personality factors correlate with regional cerebral perfusion.

    Science.gov (United States)

    O'Gorman, R L; Kumari, V; Williams, S C R; Zelaya, F O; Connor, S E J; Alsop, D C; Gray, J A

    2006-06-01

    There is an increasing body of evidence pointing to a neurobiological basis of personality. The purpose of this study was to investigate the biological bases of the major dimensions of Eysenck's and Cloninger's models of personality using a noninvasive magnetic resonance perfusion imaging technique in 30 young, healthy subjects. An unbiased voxel-based analysis was used to identify regions where the regional perfusion demonstrated significant correlation with any of the personality dimensions. Highly significant positive correlations emerged between extraversion and perfusion in the basal ganglia, thalamus, inferior frontal gyrus and cerebellum and between novelty seeking and perfusion in the cerebellum, cuneus and thalamus. Strong negative correlations emerged between psychoticism and perfusion in the basal ganglia and thalamus and between harm avoidance and perfusion in the cerebellar vermis, cuneus and inferior frontal gyrus. These observations suggest that personality traits are strongly associated with resting cerebral perfusion in a variety of cortical and subcortical regions and provide further evidence for the hypothesized neurobiological basis of personality. These results may also have important implications for functional neuroimaging studies, which typically rely on the modulation of cerebral hemodynamics for detection of task-induced activation since personality effects may influence the intersubject variability for both task-related activity and resting cerebral perfusion. This technique also offers a novel approach for the exploration of the neurobiological correlates of human personality.

  9. 重型颅脑外伤灌注CT结果与脑灌注压的相关性%Correlation of brain perfusion computed tomography results and cerebral perfusion pressure in patients with severe head trauma

    Institute of Scientific and Technical Information of China (English)

    徐裕; 冯东侠; 高恒; 那汉荣; 徐伟东; 周新民

    2012-01-01

    目的 探讨重型颅脑外伤患者灌注CF结果与脑灌注压监测结果的相关性.方法 50例重型颅脑外伤患者分为两组:T组28例,C组22例,人院时头颅CT平扫有明显异常.在行灌注CT时,同时监测平均动脉压(MAP)及颅内压(ICP),计算脑灌注压(CPP).应用直线回归分析灌注CT参数[局部脑血容量(rCBV)、局部脑血流(rCBF)和平均通过时间(MTT)]与CPP的相关性.结果 根据灌注CT结果,T组分为两个亚组:T1组,16例,灌注CT结果与CPP呈弱相关;T2组,12例,两者存在强相关.T1、T2和C组间的灌注CT参数均有明显差异.T1组的rCBF为(18.8±8.0)cm3·100g1·min-2,明显低于T2组的(60.2±21.3)cm3·100g1·min-1和C组的(48.3±11.0)CM3·100g1·min-1(P<0.01).T1、T2组灌注CT参数与相应CPP值之间均显著相关(P<0.01).结论 灌注CT结合ICP监测能提供有价值的评估脑血管自动调节功能是否完好的信息,有助于指导治疗.%Objective To investigate the correlation of brain perfusion computed tomography (CT) results and cerebral perfusion pressure (CPP) in patients with severe head trauma. Methods Perfusion CT results of 50 patients with head trauma were analyzed , who were divided into two groups of T(28 cases, severe head trauma with abnormal CT findings during admission) and C(22 cases,head trauma with normal CT findings during admission). The patients underwent perfusion CT and MAP and ICP were measured at the same time, by which CPP was calculated. The correlation between perfusion CT results [regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF) and MTT] and corresponding CPP was analyzed using linear regression analysis. Results According to perfusion CT results, group T was divided into two subgroups of Tl (16 cases, characterized by a weak correlation between the perfusion-CT results and the corresponding CPP values) and T2(12 cases,characterized by a strong correlation between the perfusion-CT results and the corresponding

  10. Blood Pressure is Associated With Cerebral Blood Flow Alterations in Patients With T2DM as Revealed by Perfusion Functional MRI.

    Science.gov (United States)

    Xia, Wenqing; Rao, Hengyi; Spaeth, Andrea M; Huang, Rong; Tian, Sai; Cai, Rongrong; Sun, Jie; Wang, Shaohua

    2015-12-01

    Type 2 diabetes mellitus (T2DM) and hypertension are both associated with cognitive impairment and brain function abnormalities. We investigated whether abnormal cerebral blood flow (CBF) patterns exists in T2DM patients and possible relationships between aberrant CBF and cognitive performance. Furthermore, we examined the influence of hypertension on CBF alterations in T2DM patients. T2DM patients (n = 38) and non-T2DM subjects (n = 40) were recruited from clinics, hospitals, and normal community health screenings. Cerebral blood flow images were collected and analyzed using arterial spin labeling perfusion functional magnetic resonance imaging (fMRI). Regions with major CBF differences between T2DM patients and non-T2DM controls were detected via 1-way ANOVA. The interaction effects between hypertension and T2DM for CBF alterations were also examined. Correlation analyses illustrated the association between CBF values and cognitive performance and between CBF and blood pressure. Compared with non-T2DM controls, T2DM patients exhibited decreased CBF, primarily in the visual area and the default mode network (DMN); decreased CBF in these regions was correlated with cognitive performance. There was a significant interaction effect between hypertension and diabetes for CBF in the precuneus and the middle occipital gyrus. Additionally, blood pressure correlated negatively with CBF in T2DM patients.T2DM patients exhibited reduced CBF in the visual area and DMN. Hypertension may facilitate a CBF decrease in the setting of diabetes. T2DM patients may benefit from blood pressure control to maintain their brain perfusion through CBF preservation.

  11. 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......-up tilt. Mean arterial pressure, cardiac output, middle cerebral artery mean flow velocity (MCA V(mean)), and dynamic cerebral autoregulation at supine rest and 70 degrees head-up tilt were determined during free breathing and with Pet(CO(2)) clamped to the supine level. The postural changes in central...

  12. Hypertonic saline solution increases cerebral perfusion pressure during clinical orthotopic liver transplantation for fulminant hepatic failure: preliminary results Solução salina hipertônica aumenta a pressão de perfusão cerebral no transplante do fígado para hepatite fulminante: resultados preliminares

    Directory of Open Access Journals (Sweden)

    Joel Avancini Rocha Filho

    2006-06-01

    Full Text Available During orthotopic liver transplantation for fulminant hepatic failure, some patients may develop sudden deterioration of cerebral perfusion and oxygenation, mainly due to increased intracranial pressure and hypotension, which are likely responsible for postoperative neurological morbidity and mortality. In the present study, we hypothesized that the favorable effects of hypertonic saline solution (NaCl 7.5%, 4 mL/kg infusion on both systemic and cerebral hemodynamics, demonstrated in laboratory and clinical settings of intracranial hypertension and hemorrhagic shock resuscitation, may attenuate the decrease in cerebral perfusion pressure that often occurs during orthotopic liver transplantation for fulminant hepatic failure. METHODS: 10 patients with fulminant hepatic failure in grade IV encephalopathy undergoing orthotopic liver transplantation with intracranial pressure monitoring were included in this study. The effect on cerebral and systemic hemodynamics in 3 patients who received hypertonic saline solution during anhepatic phase (HSS group was examined, comparing their data with historical controls obtained from surgical procedure recordings in 7 patients (Control group. The maximal intracranial pressure and the corresponding mean arterial pressure values were collected in 4 time periods: (T1 the last 10 min of the dissection phase, (T2 the first 10 minutes at the beginning of anhepatic phase, (T3 at the end of the anhepatic phase, and (T4 the first 5 minutes after graft reperfusion. RESULTS: Immediately after hypertonic saline solution infusion, intracranial pressure decreased 50.4%. During the first 5 min of reperfusion, the intracranial pressure remained stable in the HSS group, and all these patients presented an intracranial pressure lower than 20 mm Hg, while in the Control group, the intracranial pressure increased 46.5% (P Neste estudo testamos a hipótese de que os efeitos benéficos decorrentes da administração da solu

  13. Magnetic resonance perfusion imaging evaluation in perfusion abnormalities of the cerebellum after supratentorial unilateral hyperacute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Pan Liang; Yunjun Yang; Weijian Chen; Yuxia Duan; Hongqing Wang; Xiaotong Wang

    2012-01-01

    Magnetic resonance imaging (MRI) data of 10 patients with hyperacute cerebral infarction (≤ 6 hours) were retrospectively analyzed. Six patients exhibited perfusion defects on negative enhancement integral maps, four patients exhibited perfusion differences in pseudo-color on mean time to enhance maps, and three patients exhibited perfusion differences in pseudo-color on time to minimum maps. Dynamic susceptibility contrast-enhanced perfusion weighted imaging revealed a significant increase in region negative enhancement integral in the affected hemisphere of patients with cerebral infarction. The results suggest that dynamic susceptibility contrast-enhanced perfusion weighted imaging can clearly detect perfusion abnormalities in the cerebellum after unilateral hyperacute cerebral infarction.

  14. 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.

  15. 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.

  16. Changes in Cerebral Perfusion around the Time of Delayed Cerebral Ischemia in Subarachnoid Hemorrhage Patients

    NARCIS (Netherlands)

    Dankbaar, J. W.; de Rooij, N. K.; Smit, E. J.; Velthuis, B. K.; Frijns, C. J. M.; Rinkel, G. J. E.; van der Schaaf, I. C.

    2011-01-01

    Background: Because the pathogenesis of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) is unclear, we studied cerebral perfusion at different time points around the occurrence of DCI. Methods: We prospectively enrolled 53 patients admitted to the University Medical Center Utrech

  17. Relationship between vasospasm, cerebral perfusion, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

    NARCIS (Netherlands)

    Dankbaar, Jan W.; Rijsdijk, Mienke; van der Schaaf, Irene C.; Velthuis, Birgitta K.; Wermer, Marieke J. H.; Rinkel, Gabriel J. E.

    2009-01-01

    Vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is thought to cause ischemia. To evaluate the contribution of vasospasm to delayed cerebral ischemia (DCI), we investigated the effect of vasospasm on cerebral perfusion and the relationship of vasospasm with DCI. We studied 37 consecutive SAH

  18. Cerebral perfusion and cerebral ischemia in patients with symptomatic carotid artery stenosis

    NARCIS (Netherlands)

    Jongen, L.M.

    2010-01-01

    Next to thromboembolism from the atherosclerotic plaque, impaired cerebral perfusion is the main mechanism of cerebral ischemia in patients with symptomatic carotid artery stenosis. There is supporting evidence of a synergistic effect of both embolic and hemodynamic factors. An understanding of both

  19. Arterial spin labeling perfusion MRI in cerebral ischaemia

    NARCIS (Netherlands)

    Bokkers, R.P.H.

    2011-01-01

    Cerebral perfusion is the basis for the delivery of oxygen and nutrients to the brain. Brain tissue can become damaged when there is a shortage in the blood supply. Basic physiological functions such as synaptic transmission, the membrane ion pump and energy metabolism are disrupted and within minut

  20. 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.

  1. PET imaging of cerebral perfusion and oxygen metabolism in stroke

    Energy Technology Data Exchange (ETDEWEB)

    Pointon, O.; Yasaka, M.; Berlangieri, S.U.; Newton, M.R.; Thomas, D.L.; Chan, C.G.; Egan, G.F.; Tochon-Danguy, H.J.; O``Keefe, G.; Donnan, G.A.; McKay, W.J. [Austin Hospital, Melbourne, VIC (Australia). Centre for PET and Depts of Nuclear Medicine and Neurology

    1998-03-01

    Full text: Stroke remains a devastating clinical event with few therapeutic options. In patients with acute stroke, we studied the cerebral perfusion and metabolic patterns with {sup 15}O-CO{sub 2} or H{sub 2}O and {sup 15}O-O{sub 2} positron emission tomography and correlated these findings to the clinical background. Forty three patients underwent 45 studies 0-23 days post-stroke (mean 7 days). Fifteen patients showed luxury perfusion (Group A), 10 had matched low perfusion and metabolism (B) and 3 showed mixed pattern including an area of misery perfusion (C). Seventeen showed no relevant abnormality (D) and there were no examples of isolated misery perfusion. Twelve of the 15 in Group A had either haemorrhagic transformation on CT, re-opening on angiography, or a cardioembolic mechanism. In contrast only 5/10 in Group B, 0/3 in Group C and 2/17 in Group D had these features. Although 7/10 in group B had moderate or large size infarcts on CT the incidence of haemorrhagic transformation was low (2/10) and significant carotid stenoses were more common in those studied (5/8) compared with the other groups. Misery perfusion was not seen beyond five days. Thus, luxury perfusion seems to be related to a cardio-embolic mechanism or reperfusion. Matched low perfusion and metabolism was associated with a low rate of haemorrhagic transformation despite a high incidence of moderate to large size infarcts. Misery perfusion is an early phenomenon in the evolution of ischaemic stroke.

  2. 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

  3. 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

  4. Method for performing cerebral perfusion-weighted MRI in neonates

    Energy Technology Data Exchange (ETDEWEB)

    Laswad, Tarek; Alamo, Leonor; Meuli, Reto; Gudinchet, Francois [University of Lausanne (CH). Radiology Department, Lausanne (Switzerland)]|[Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne (Switzerland); Wintermark, Pia; Moessinger, Adrien [University of Lausanne, Division of Neonatology, Lausanne (Switzerland)]|[Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne (Switzerland)

    2009-03-15

    Cerebral perfusion-weighted imaging (PWI) in neonates is known to be technically difficult and there are very few published studies on its use in preterm infants. In this paper, we describe one convenient method to perform PWI in neonates, a method only recently used in newborns. A device was used to manually inject gadolinium contrast material intravenously in an easy, quick and reproducible way. We studied 28 newborn infants, with various gestational ages and weights, including both normal infants and those suffering from different brain pathologies. A signal intensity-time curve was obtained for each infant, allowing us to build perfusion maps. This technique offered a fast and easy method to manually inject a bolus gadolinium contrast material, which is essential in performing PWI in neonates. Cerebral PWI is technically feasible and reproducible in neonates of various gestational age and with various pathologies. (orig.)

  5. 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)

  6. 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.)

  7. 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 cerebral...... metabolism (from arterial and internal jugular venous O(2), glucose and lactate differences), as well as the middle cerebral artery mean blood velocity (MCA V(mean); transcranial Doppler ultrasound) during a sustained static handgrip contraction at 40% of maximal voluntary contraction (n = 9) and the MCA V...... abolished by glycopyrrolate (P perfusion without affecting the cerebral metabolic rate for oxygen....

  8. Value of cerebral perfusion and vascular reserve for the treatment of symptomatic intracranial arterial stenosis

    Institute of Scientific and Technical Information of China (English)

    Li'an Huang; Xuewen Song; Anding Xu

    2008-01-01

    BACKGROUND: It is crucial to understand cerebral perfusion and vascular reserve in stegnotic arterial blood-supply regions to treat ischemic cerebrovascular diseases. However, effects on symptomatic intracrani-al arterial stenosis (SICAS) need to be further studied in additional applications. OBJECTIVE: To evaluate and summarize the effects of cerebral perfusion and vascular reserve on the treatment of SICAS. RETRIEVAL STRATEGY: A computer-based online search of English language publications from January 2000 to July 2007 was conducted in PubMed to identify publications that addressed cerebral perfusion and vascular reserve of SICAS. Search key words were "intracranial stenosis, perfusion, brain reserve". Relevant data were also searched with the China Journal Net, using the same key words in Chinese from January 2000 to January 2007. In total, 101 articles were retrieved. Inclusion criteria: ① Articles describing the current status for the diagnosis and treatment of SICAS; ② Articles concerning research developments of cerebral perfusion and vascular reserve of SICAS. Exclusion criteria: duplicated articles. LITERATURE EVALUATION: This study included 21 articles of experimental studies and conference re-ports.DATA SYNTHESIS: When performing interventional surgery in SICAS patients, it is important to under-stand cerebral perfusion and vascular reserve in addition to knowing the clinical symptoms and degrees of arterial stenosis. In recent years, there are a growing number of reports on measurements of vascular reserve through the use of magnetic resonance perfusion imaging (MR-PWI). Investigations demonstrate cerebral perfusion and vascular reserve decrease in many SICAS patients. Many studies show that both improve after surgical intervention. CONCLUSION: Cerebral perfusion could provide direct evidence of whether ischemia has occurred in the brain. Because of lateral circulation and cerebral vascular reserve, intracranial vascular stenosis and/or decreased

  9. Is misery perfusion still a predictor of stroke in symptomatic major cerebral artery disease?

    Science.gov (United States)

    Yamauchi, Hiroshi; Higashi, Tatsuya; Kagawa, Shinya; Nishii, Ryuichi; Kudo, Takashi; Sugimoto, Kanji; Okazawa, Hidehiko; Fukuyama, Hidenao

    2012-08-01

    Studies in the 1990s demonstrated that misery perfusion is a predictor of subsequent stroke in medically treated patients with symptomatic major cerebral artery disease. A recent randomized controlled trial demonstrated no benefit of bypass surgery for such patients. In this light, outcome in patients with misery perfusion has regained interest. The purpose of this study was to determine whether misery perfusion is still a predictor of subsequent stroke despite recent improvements in medical treatment for secondary prevention of stroke, and if so, whether the predictive value of misery perfusion has changed in recent years. We prospectively studied 165 non-disabled patients with symptomatic atherosclerotic internal carotid artery or middle cerebral artery occlusive diseases who underwent positron emission tomography from 1999 to 2008. Misery perfusion was defined as decreased cerebral blood flow, increased oxygen extraction fraction and decreased ratio of cerebral blood flow to blood volume in the hemisphere supplied by the diseased artery. All patients were followed up for 2 years until stroke recurrence or death. Bypass surgery was performed in 19 of 35 patients with and 16 of 130 patients without misery perfusion. The 2-year incidence of ipsilateral ischaemic stroke was six and four patients with and without misery perfusion, including two and one after surgery, respectively (P misery perfusion and 12 patients without (P misery perfusion in whole sample was 6.3 (95% confidence interval 1.7-22.4, P misery perfusion or bypass surgery did not differ. Between these periods, patients without misery perfusion demonstrated a decrease in stroke rate (from 16.2% to 0%), but patients with misery perfusion did not (26.3 and 25.0%). In symptomatic major cerebral artery disease, misery perfusion remains a predictor of subsequent stroke, although the recurrence rate was lower than the previous study. In patients without misery perfusion, the risk of stroke was reduced

  10. 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.

  11. Maladaptation of cerebral perfusion in the spinal cord injured individuals

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Ihn Ho; Chun, Kyung A.; Lee, Hyoung Woo; Ahn, Sang Ho; Hayashida, Kohei [National Cardiovascular Center, Osaka (Korea, Republic of)

    2001-07-01

    The aim of this study was to evaluate the tilt-induced alteration of cerebral perfusion of spinal cord injured individuals. Supine and upright sitting brain SPECT was performed using a 1-day protocol with {sup 99m}Tc-ethylcysteinate dimer (ECD) in 11 SCI individuals (mean age, 32.6 y), with lesions between C3 and T4, ad 5 AB individuals (mean age, 31.4 y). The patients rested on a wheelchair in the supine position. Then, they sat up and, at the same time 555MBq of ECD was injected. The upright SPECT was done. Finally, 740MBq of ECD was injected and supine SPECT was performed again. The SPECT data were acquired with dual head gamma camera (E-cam, Siemens). For semiquantitative analysis, 14 ROIs were drawn on the brain. In the SCI individuals, the radiotracer uptake in the frontal, temporal and parietal areas were significantly decreased in the upright SPECT. No postural changes was evident in the occipital lobe, basal ganglia and thalamus in the SCI individuals. In the AB individuals, there were no such changes on the upright SPECT. Postural cerebral hypoperfusion in the frontal, temporal and parietal areas in the SCI individuals might relate to maladaptation of the vascular response during the upright position.

  12. Comparison of Cerebral Oxygen Saturation and Cerebral Perfusion Computed Tomography in Cerebral Blood Flow in Patients with Brain Injury.

    Science.gov (United States)

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Grigoryeva, Vera

    2016-01-01

    The purpose of this study was to determine the relationship between cerebral tissue oxygen saturation and cerebral blood volume in patients with traumatic brain injury. Perfusion computed tomography of the brain was performed in 25 patients with traumatic brain injury together with simultaneous SctO2 level measurement using cerebral near-infrared oxymetry. The mean age of the injured persons was 34.5±15.6 years (range 15-65); 14 men, 11 women. The Injury Severity Score (ISS) values were 44.4±9.7 (range 25-81). The Glasgow Coma Score (GCS) mean value before the study was 10.6±2.1 (range 5-13). SctO2 ranged from 51 to 89%, mean 62±8.2%. Cerebral blood volume (CBV) values were 2.1±0.67 ml/100 g (min 1.1; max 4.3 ml/100 g). Cerebral blood flow (CBF) was 31.99±13.6 ml/100 g×min. Mean transit time (MTT) values were 5.7±4.5 s (min 2.8; max 34.3 s). The time to peak (TTP) was 22.2±3.1 s. A statistically significant correlation was found between SctO2 level and cerebral blood volume (CBV) level (R=0.9; pperfusion.

  13. A study of cerebral perfusion using single photon emission computed tomography in neonates with brain lesions

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, J.; Contantinesco, A.; Brunot, B.; Messer, J. (Hospital Universitaire de Strasbourg (France))

    1994-03-01

    In this study the authors used a single photon emission computed tomography technique (SPECT) with radiolabelled [sup 99m]Tc HMPAO to assess cerebral perfusion in newborn infants with documented cerebral lesions and to determine to what extent brain SPECT might be useful in the neonatal period. A total of 15 newborn infants with the following cerebral pathologies were enrolled: severe parietal bilateral periventricular leucomalacia; moderate parietal bilateral PVL; intraventricular haemorrhage grade II with unilateral parietal parenchymal extension; cerebral infarction in the zone of middle cerebral artery; and post-haemorrhagic hydrocephalus. Follow-up was available in all infants. Alterations in cerebral perfusion were seen in only 12 of 15 infants and at the location of severe PVL, PE and CI. It was noted that the regions of diminished perfusion extended beyond the apparent extent of cerebral pathology delineated by ultrasound or magnetic resonance imaging. Markedly diminished perfusion was seen in one infant with hydrocephalus, which recovered following placement of ventriculo-peritoneal shunt. Regarding outcome, SPECT data failed to provide additional information than that of neuroradiological investigations. It is concluded that the use of SPECT, under these conditions, to assess alteration of cerebral perfusion in the neonatal period will not provide any additional information than that of neuroradiological investigations. 17 refs., 3 figs., 1 tab.

  14. Effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies

    Science.gov (United States)

    Murase, Kenya; Nanjo, Takafumi; Satoshi, Ii; Miyazaki, Shohei; Hirata, Masaaki; Sugawara, Yoshifumi; Kudo, Masayuki; Sasaki, Kousuke; Mochizuki, Teruhito

    2005-11-01

    The purpose of this study was to investigate the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using multi-detector row CT (MDCT). Following the standard CT perfusion study protocol, continuous (cine) scans (1 s/rotation × 60 s) consisting of four 5 mm thick contiguous slices were performed using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. We generated the simulated images with tube currents of 50 mA, 100 mA and 150 mA by adding the corresponding noise to the raw scan data of the original image acquired above using a noise simulation tool. From the original and simulated images, we generated the functional images of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in seven patients with cerebrovascular disease, and compared the correlation coefficients (CCs) between the perfusion parameter values obtained from the original and simulated images. The coefficients of variation (CVs) in the white matter were also compared. The CC values deteriorated with decreasing tube current. There was a significant difference between 50 mA and 100 mA for all perfusion parameters. The CV values increased with decreasing tube current. There were significant differences between 50 mA and 100 mA and between 100 mA and 150 mA for CBF. For CBV and MTT, there was also a significant difference between 150 mA and 200 mA. This study will be useful for understanding the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using MDCT, and for selecting the tube current.

  15. 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.

  16. 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)

  17. Helical CT study of cerebral perfusion and related hemodynamic parameters

    Science.gov (United States)

    Cenic, Aleksa; Lee, Ting-Yim; Craen, Rosemary A.; Gelb, Adrian W.

    1997-05-01

    A convenient method for assessing cerebral perfusion and related functional parameters has been developed using a third generation slip-ring CT scanner. Dynamic contrast- enhanced scanning at the same level was employed to image the cerebral circulation at the rate of 1 image per second. Using data acquired with this non-helical mode of scanning, we have developed a method for the simultaneous in-vivo determination of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT). These measurements are given in the same physiological units as positron emission tomography. In order to obtain accurate measurements of these parameters, methods were also developed to correct for recirculation and partial volume averaging in imaging small blood vessels. We have used 6 New Zealand white rabbits in our studies. For each rabbit, up to 3 CT measurements of CBF, CBV, and MTT were made at normocapnia under isoflurane anesthesia. Coronal sections through the brain were imaged while simultaneously imaging either a brain artery or the ear artery. Images were acquired for 1 minute as Isovue 300 was injected intravenously. In the acquired CT images, regions of interest in brain parenchyma and an artery were drawn. For each region of interest, the mean CT number in pre-contrast images was subtracted from the mean in post-contrast images to calculate the contrast concentration curves for the brain regions Q(t) and the arterial region Ca(t). Using a robust deconvolution method, the MTT was determined. CBV was then determined from the ratio of the areas of Q(t) and Ca(t). Finally, CBF was calculated from the Central Volume Principle. The mean regional CBF, CBV and MTT values were 73.3 +/- 5.1 ml/min/100g, 1.93 +/- 0.12 ml/100g and 1.80 +/- 0.18 s respectively. IN order to validate our CT CBF measurements, we also measured CBF using the well- established technique of microspheres with each CT study. The feasibility of our CT method to measure CBF accurately was

  18. Aortic outflow cannula tip design and orientation impacts cerebral perfusion during pediatric cardiopulmonary bypass procedures.

    Science.gov (United States)

    Menon, Prahlad G; Antaki, James F; Undar, Akif; Pekkan, Kerem

    2013-12-01

    Poor perfusion of the aortic arch is a suspected cause for peri- and post-operative neurological complications associated with cardiopulmonary bypass (CPB). High-speed jets from 8 to 10FR pediatric/neonatal cannulae delivering ~1 L/min of blood can accrue sub-lethal hemolytic damage while also subjecting the aorta to non-physiologic flow conditions that compromise cerebral perfusion. Therefore, we emphasize the importance of cannulation strategy and hypothesize engineering better CPB perfusion through a redesigned aortic cannula tip. This study employs computational fluid dynamics to investigate novel diffuser-tipped aortic cannulae for shape sensitivity to cerebral perfusion, in an in silico cross-clamped aortic arch model modeled with fixed outflow resistances. 17 parametrically altered configurations of an 8FR end-hole and several diffuser cone angled tips in combination with jet incidence angles toward or away from the head-neck vessels were studied. Experimental pressure-flow characterizations were also conducted on these cannula tip designs. An 8FR end-hole aortic cannula delivering 1 L/min along the transverse aortic arch was found to give rise to backflow from the brachicephalic artery (BCA), irrespective of angular orientation, for the chosen ascending aortic insertion location. Parametric alteration of the cannula tip to include a diffuser cone angle (tested up to 7°) eliminated BCA backflow for any tested angle of jet incidence. Experiments revealed that a 1 cm long 10° diffuser cone tip demonstrated the best pressure-flow performance improvement in contrast with either an end-hole tip or diffuser cone angles greater than 10°. Performance further improved when the diffuser was preceded by an expanded four-lobe swirl inducer attachment-a novel component. In conclusion, aortic cannula orientation is crucial in determining net head-neck perfusion but precise angulations and insertion-depths are difficult to achieve practically. Altering the cannula tip

  19. Hypothermic Machine Perfusion of Kidney Grafts: Which Pressure is Preferred?

    NARCIS (Netherlands)

    B.M. Doorschodt; M.C.J.M. Schreinemachers; M. Behbahani; S. Florquin; J. Weis; M. Staat; R.H. Tolba

    2011-01-01

    To assess the effect of the perfusion pressure (PP) during machine perfusion (MP) on the preservation quality of kidney grafts, we compared mean PPs of 25 and 30 mmHg using a porcine autotransplantation model. After assessment of the microcirculation, animals underwent left nephrectomy. Thereafter,

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. 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

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

    NARCIS (Netherlands)

    R.V. Immink; J. Truijen; N.H. Secher; J.J. van Lieshout

    2009-01-01

    Immink RV, Truijen J, Secher NH, Van Lieshout JJ. Transient influence of end-tidal carbon dioxide tension on the postural restraint in cerebral perfusion. J Appl Physiol 107: 816-823, 2009. First published July 2, 2009; doi: 10.1152/japplphysiol.91198.2008.-In the upright position, cerebral blood fl

  4. Predicting hemorrhagic transformation by microvascular permeability using perfusion CT acute cerebral infarction in elderly patients

    Institute of Scientific and Technical Information of China (English)

    田超

    2014-01-01

    Objective To study the possibility of microvascular permeability(PS)value derived from perfusion CT(PCT)in predicting hemorrhagic transformation(HT)in acute cerebral infarction in elderly patients.Methods 52consecutive patients with middle cerebral artery acute ischemic stroke who received thrombolytic therapy were divided into HT group and control group,and patients in

  5. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward;

    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 onl...

  6. 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.

  7. 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...

  8. Effect of propofol and remifentanil on cerebral perfusion and oxygenation in pigs

    DEFF Research Database (Denmark)

    Mikkelsen, Mai Louise Grandsgaard; Ambrus, Rikard; Miles, James Edward;

    2016-01-01

    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...

  9. 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.

  10. 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], ...

  11. Cerebral hemodynamics after short- and long-term reduction in blood pressure in mild and moderate hypertension.

    NARCIS (Netherlands)

    Zhang, R.; Witkowski, S.; Fu, Q.; Claassen, J.A.H.R.; Levine, B.D.

    2007-01-01

    This study tested the hypothesis that acute reduction in blood pressure (BP) at the initial stage of antihypertensive therapy compromises brain perfusion and dynamic cerebral autoregulation in patients with hypertension. Cerebral blood flow velocity and BP were measured in patients with mild and mod

  12. 轻度过度通气对幕上占位开颅患者麻醉后颅内压、脑灌注压以及血流动力学影响%The influence of mild hyperventilation to intracranial pressure,cerebral perfusion pressure and hemodynamics during supratentorial craniotomy

    Institute of Scientific and Technical Information of China (English)

    陈一丁; 张宏伟; 唐育民; 张兆辉; 罗江辉

    2011-01-01

    Objective To observe the influence of mild hyperventilation to intracranial pressure (ICP) 、cerebral perfusion pressure (CPP) and hemodynamic during supratentorial craniotomy, and to provide evidence for applicable neurosurgical anesthesiology. Methods 21 patients with supratentorial tumor were given mild hyperventilation, with EtCO2 30 ~ 35mmHg and peak airway pressure 10 ~18cmH2O. The ICP through lumbar cerebrospinal fluid pressure, the central venous pressure (CVP) in superior vena cava, the intra-abdominal pressure (IAP) through intra-bladder pressure (IBP), the mean arterial pressure (MAP)by peripheral arterial cannulation, and CPP were analyzed during the period from anesthesia induction to opening the hard meninges. Results The mild hyperventilation significantly increased the CVP、IBP and ICP, while significantly decreased the MAP and CPP in patients under anesthesia. Conclusion It's essential to remove skull bone flap to decrease ICP as soon as possible after anesthesia and positive ventilation, to prevent the abrupt decreasing of CPP. The mild hyperventilation doesn't provide beneficial effects to cerebral perfusion, and further comparative study for ventilation strategy should be designed.%目的 观察轻度过度通气对幕上占住开颅患者麻醉后颅内压、脑灌注压以及血流动力学的影响.为临床上合理的神经外科麻醉方法提供依据.方法 对21例幕上占位开颅患者给予轻度过度通气,控制呼吸末CO 30~35mmHg和气道峰压10~18cmHO,在全麻诱导前至开硬脑膜后这一时间段,分析经腰段脑脊液监测颅内压、经上腔静脉监测中心静脉压、经膀胱监测腹腔压、经有创动脉监测平均动脉压以及脑灌注压变化.结果 轻度过度通气显著增高了全麻后患者中心静脉压,膀胱压和颅内压,降低了平均动脉压和脑灌注压.结论 麻醉正压通气后应尽快开颅减压,降低颅内压,避免脑灌注压过度下降.轻度过度通气

  13. 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)

  14. A study on cerebral hemodynamic analysis of moyamoya disease by using perfusion MRI

    Science.gov (United States)

    Dong, Kyung-Rae; Goo, Eun-Hoe; Lee, Jae-Seung; Chung, Woon-Kwan

    2013-10-01

    This study examined the clinical applications of perfusion magnetic resonance imaging (MRI) in patients with moyamoya disease (MMD). Twenty-two patients with moyamoya disease (9 men and 13 women) with a mean age of 9.3 years (range: 4-22 years) were enrolled in this study. Perfusion MRI was performed by scanning the patients7.5 cm upward from the base of the cerebellum before their being process for post-treatment. The scan led to the acquisition of the following four map images: the cerebral blood volume (CBV), the cerebral blood flow (CBF), the mean transit time (MTT) for the contrast medium, and the time to peak (TTP) for the contrast medium. The lesions were assessed using the CBV, the CBF, the MTT and the TTP maps of perfusion MRI; the MTT and the TTP were measured in the lesion areas, as well as in the normal and the symmetric areas. Perfusion defects were recognizable in all four perfusion MRI maps, and the MTT and the TTP showed a conspicuous delay in the parts where perfusion defects were recognized. The MTT and the TTP images of perfusion MRI reflected a significant correlation between the degrees of stenosis and occlusion in the posterior cerebral artery (PCA), as well as the development of collateral vessels. The four perfusion MRI maps could be used to predict the degrees of stenosis and occlusion in the posterior circulation, as well as the development of the collateral vessels, which enabled a hemodynamic evaluation of the parts with perfusion defects. Overall, perfusion MRI is useful for the diagnosis and the treatment of moyamoya disease and can be applied to clinical practice.

  15. Evaluation of multislice computed tomographic perfusion imaging and computed tomographic angiography on traumatic cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    XU Fang-hong; CHEN Wei-jian; YANG Yun-jun; DUAN Yu-xia; FU Feng-li

    2008-01-01

    Objective: To evaluate the application value of multislice computed tomographic perfusion imaging (MSCTPI) and multislice computed tomographic angiography (MSCTA) on traumatic cerebral infarction. Methods: MSCTA was performed on 10 patients who were initiailly diagnosed as traumatic cerebral infarction by normal conventional computed tomography (NCCT), among whom, 3 patients were examined by MSCTPI simultaneously. Reconstructed images of the intracranial artery were made with techniques of maximum intensity projection (MIP) and volume rendering (VR) from MSCTA scanning data. Then the graph of function of four parameters, regional cerebral blood flow (Rcbf), regional cerebral blood volume (Rcbv), mean transit time (MTT), and time to peak (TTP), acquired by the perfusing analysis software was obtained. Results: Among the 10 patients with traumatic cerebral infarction, 6 showed complex type on NCCT, which depicted abnormality on MSCTA, and 4 showed simple type on NCCT, which had negative results on MSCTA. Among the 4 patients with abnormal great vessels, 2 suffered from steno sis or occlusion of the middle cerebral artery, 1 from spasm of the anterior cerebral artery, and 1 from spasm of the vertebral-basal artery. The image of MSCTPI of 1 patient with massive cerebral infarction on the right cerebral hemisphere confirmed by CT was smaller than those of the other patients, which showed occlusion of the ipsilateral middle cerebral artery on MSCTA. Among the 6 patients whose MSCTA showed no abnormality, 4 showed simple infarction and 2 showed complex infarction. The infarction focus of 5 patients occurred in the basal ganglia and 1 in the splenium of corpus callosum. Among the 2 cases of small cerebral infarction volume on NCCT, one was normal, the other showed hypoperfusion on MSCTPI and was normal on MSCTA. Conclusion: The combination of MSCTPI and MSCTA is very useful for evaluating the change of intracranial artery in ischemic regions and assessing the cerebral

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

    Directory of Open Access Journals (Sweden)

    Dartiu X da Silveira

    2001-03-01

    Full Text Available 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 alterações de perfusão cerebral, focais ou difusas, com grau de intensidade variável. Não foram observadas diferenças de perfusão cerebral entre usuários de crack e usuários de cloridrato de cocaína. As alterações tomográficas tampouco permitiram distinguir os dependentes em abstinência dos dependentes na vigência do uso. Não foi possível evidenciar associação entre o relato da quantidade diária de droga utilizada e a perfusão cerebral dos pacientes. Entretanto, foi observada correlação entre o número de meses durante os quais os pacientes consumiram droga e o grau de comprometimento da perfusão cerebral (coeficiente de correlação de Spearman: r=0,45, pOBJECTIVE: To evaluate the relationship between the pattern of cocaine use and cerebral perfusion among cocaine addicts. METHOD: A sample of 30 cocaine addicts was studied using 99 m-Tc-HMPAO SPECT (single photon emission computed tomography with injection of 99 m-Tc-hexametilpropilenoamina-oxime. Their cerebral perfusion pattern was then compared with their pattern of cocaine use. RESULTS: Eighty percent of the sample presented some degree of impairment in brain perfusion, either focal or diffuse. There was no difference between sniffers and crack smokers regarding their perfusion patterns. No relationship could be established between the severity of SPECT abnormalities and the amount of drug consumption or period of abstinence. However, length of cocaine use did

  17. Echo planar diffusion and perfusion MRI detect pathophysiological heterogeneity in cerebral contusion

    Energy Technology Data Exchange (ETDEWEB)

    Aoyama, Naoki; Mori, Tatsuro; Maeda, Takeshi; Kawamata, Tatsuro; Katayama, Yoichi [Nihon Univ., Tokyo (Japan). School of Medicine

    2000-06-01

    Cerebral contusions have heterogeneous mechanisms of early edema formation and frequently cause elevation of ICP and resultant clinical deterioration. In the present study, in order to investigate the mechanisms of early contusion edema, diffusion-weighted imaging, apparent diffusion coefficient (ADC) mapping and perfusion imaging were performed using 1.5 T echo planar imaging (EPI) in patients with cerebral contusion. On diffusion image within 24 hours post-trauma, the central area of the contusion were demonstrated as low intensity. In contrast, the peripheral area had high intensity. The ADC value increased in the central area and decreased in peripheral area. During 24-48 hours post-trauma, a crescent-shaped zone of very high ADC value was observed at the border between these two areas. These results indicate that, in early phase of cerebral contusion, cytotoxic edema is predominantly present in the peripheral area and edema fluid accumulates at the border between central and peripheral area of cerebral contusion 24-48 hours post-trauma. Perfusion imaging demonstrates wide spread CBF depression within the cerebral contusion. Diffusion and perfusion image using EPI are useful for evaluating heterogeneous mechanisms of early edema formation and CBF changes in the acute phase of cerebral contusion. (author)

  18. Perfusion pressure flow study in the upper urinary tract

    Directory of Open Access Journals (Sweden)

    Hong-Lin Cheng

    2015-06-01

    Full Text Available Hydronephrosis with an undetermined pathology is a common condition detected in imaging studies. In urological clinical practice, it is a persistent dilemma to predict whether this condition will progress to result in the deterioration of renal function. Perfusion pressure flow study of the upper urinary tract, known as the Whitaker test, provides an alternative diagnostic tool for solving this condition. Perfusion pressure flow study has been criticized for its invasiveness, nonphysiological approach, and inconsistency in predicting outcomes. However, it continues to be used to evaluate difficult or equivocal cases and to provide an objective assessment of the upper urinary tract.

  19. 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.

  20. 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

  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. 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 cerebral...... metabolism (from arterial and internal jugular venous O(2), glucose and lactate differences), as well as the middle cerebral artery mean blood velocity (MCA V(mean); transcranial Doppler ultrasound) during a sustained static handgrip contraction at 40% of maximal voluntary contraction (n = 9) and the MCA V......(mean) during ergometer cycling (n = 8). Separate, randomized and counterbalanced trials were performed in control (no drug) conditions and following muscarinic cholinergic receptor blockade by glycopyrrolate. Glycopyrrolate increased resting heart rate from approximately 60 to approximately 110 beats min(-1...

  3. 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...

  4. The cerebral imaging using vessel-around method in the perfusion CT of the human brain

    Science.gov (United States)

    Ahn, Choong-Il; Choi, Seung-Wook; Park, Seung-Chul; Shin, Yeong-Gil; Kim, Jae-Hyoung; Chong, Gi-Bong

    2005-04-01

    Perfusion CT has been successfully used as a functional imaging technique for diagnosis of patients with hyperacute stroke. However, the commonly used methods based on curve-fitting are time consuming. Numerous researchers have investigated to what extent Perfusion CT can be used for the quantitative assessment of cerebral ischemia and to rapidly obtain comprehensive information regarding the extent of ischemic damage in acute stroke patients. The aim of this study is to propose an alternative approach to rapidly obtain the brain perfusion mapping and to show the proposed cerebral flow imaging of the vessel and tissue in human brain be reliable and useful. Our main design concern was algorithmic speed, robustness and automation in order to allow its potential use in the emergency situation of acute stroke. To obtain a more effective mapping, we analyzed the signal characteristics of Perfusion CT and defined the vessel-around model which includes the vessel and tissue. We proposed a nonparametric vessel-around approach which automatically discriminates the vessel and tissue around vessel from non-interested brain matter stratifying the level of maximum enhancement of pixel-based TAC. The stratification of pixel-based TAC was executed using the mean and standard deviation of the signal intensity of each pixel and mapped to the cerebral flow imaging. The defined vessel-around model was used to show the cerebral flow imaging and to specify the area of markedly reduced perfusion with loss of function of still viable neurons. 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. The vessel-around approach reduces the computation time significantly when compared with the perfusion imaging using the GVF. The proposed cerebral imaging shows reliable results which are validated by physicians and

  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. 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.

  7. 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

  8. 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

  9. A novel device for non-invasive cerebral perfusion assessment

    Directory of Open Access Journals (Sweden)

    Mirko Tessari

    2015-03-01

    Full Text Available Currently brain perfusion can be assessed by the means of radio-invasive methods, such as single-photon emission computed tomography and positron emission tomography, or by hightech methods such as magnetic resonance imaging. These methods are known to be very expensive, with long examination time, and finally, cannot be used for assessing brain oxygen distribution in relation to exercise and/or cognition-tests. The near infrared spectroscopy (NIRS is a non-invasive diagnostic technique. In real time it is capable of measuring tissue oxygenation using portable instrumentation with a relative low cost. We and other groups previously adopted this instrument for investigation of the oxygen consumption in the muscles at rest and during exercise. NIRS can be now used to assess brain perfusion through the intact skull in human subjects by detecting changes in blood hemoglobin concentrations. Changes in perfusion can be related to both arterial and venous problems. This novel equipment features allow for a wide field of innovative applications where portability, wearability, and a small footprint are essential. The present review shows how to use it in relation to exercise protocols of the upper and lower extremities, measured in healthy people and in conditions of arterial and chronic cerebro-spinal venous insufficiency.

  10. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

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

    1994-01-01

    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. Additi...

  11. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

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

    1994-01-01

    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...

  12. 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.

  13. 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

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

    NARCIS (Netherlands)

    Mendrik, A.M.; Vonken, E.J.; Ginneken, B. van; Jong, H.W. de; Riordan, A.; Seeters, T. van; Smit, E.J.; Viergever, M.A.; Prokop, M.

    2011-01-01

    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 radiat

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

    NARCIS (Netherlands)

    A. Mendrik (Adrienne); E.J.P.A. Vonken; B.T.J. van Ginneken (Berbke); J.R. Riordan (John ); H.W.A.M. de Jong (Hugo); T. van Seeters (Tom); E.J. Smit (Ewoud); M.A. Viergever; M. Prokop (Mathias)

    2011-01-01

    textabstractCerebral 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

  16. 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.

  17. 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...

  18. 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...

  19. [Examination of Visual Effect in Low-dose Cerebral CT Perfusion Phantom Image Using Iterative Reconstruction].

    Science.gov (United States)

    Ohmura, Tomomi; Lee, Yongbum; Takahashi, Noriyuki; Sato, Yuichiro; Ishida, Takato; Toyoshima, Hideto

    2015-11-01

    CT perfusion (CTP) is obtained cerebrovascular circulation image for assessment of stroke patients; however, at the expense of increased radiation dose by dynamic scan. Iterative reconstruction (IR) method is possible to decrease image noise, it has the potential to reduce radiation dose. The purpose of this study is to assess the visual effect of IR method by using a digital perfusion phantom. The digital perfusion phantom was created by reconstructed filtered back projection (FBP) method and IR method CT images that had five exposure doses. Various exposure dose cerebral blood flow (CBF) images were derived from deconvolution algorithm. Contrast-to-noise ratio (CNR) and visual assessment were compared among the various exposure dose and each reconstructions. Result of low exposure dose with IR method showed, compared with FBP method, high CNR in severe ischemic area, and visual assessment was significantly improvement. IR method is useful for improving image quality of low-dose CTP. PMID:26596197

  20. 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.

  1. 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......-) microvascular complications, and in 16 nondiabetic hypertensive patients. Cerebrovascular reserve capacity was lower in T2DM+ versus T2DM- and nondiabetic hypertensive patients (4.6±1.1 versus 6.0±1.6 [P

  2. A multimodal imaging study on spatial pattern of cerebral perfusion change caused by symptomatic unilateral carotid artery stenosis

    Directory of Open Access Journals (Sweden)

    Jian-rui LI

    2015-03-01

    Full Text Available Objective To investigate the spatial pattern of cerebral perfusion decrease resulting from symptomatic unilateral carotid artery stenosis and to assess the relationship between degrees of stenosis and cerebral blood flow (CBF.  Methods CT angiography (CTA and arterial spin labeling (ASL MRI cerebral perfusion were performed in 22 patients with symptomatic unilateral carotid artery stenosis. Diagnosis of carotid artery stenosis and measurement of stenosis degrees was performed by using CTA; cerebral perfusion was determined by ASL. Voxel-based analysis (VBA were applied to observe perfusion changes in patients with mild stenosis and moderate to severe stenosis, and spatial pattern of cerebral perfusion changes caused by carotid artery stenosis. Analysis based on region of interest (ROI was used to explore the relationship between degrees of stenosis and CBF. Results Twenty-two patients with symptomatic unilateral carotid artery stenosis (13 in the left side and 9 in the right included 13 cases with mild stenosis and 9 cases with moderate to severe stenosis. Compared to those with mild stenosis, patients with moderate to severe stenosis showed reduced CBF in bilateral (especially in the affected side parietal lobes (t = - 2.382, P = 0.014, frontal lobes (t = - 2.354, P = 0.015 and centrum semiovale (t = - 2.283, P = 0.017, and was basically located in bilateral cerebral watershed area. Furthermore, perfusion in these areas was negatively correlated with the degree of stenosis (r = - 0.479, P = 0.024.  Conclusions Symptomatic unilateral carotid artery stenosis may result in cerebral perfusion decreases in bilateral (particularly in the affected side watershed area and cerebral blood flow is negatively correlated with the degree of stenosis. DOI: 10.3969/j.issn.1672-6731.2015.02.006

  3. Seizures following carotid endarterectomy in patients with severely compromised cerebral circulation

    DEFF Research Database (Denmark)

    Nielsen, Tina G; Sillesen, H; Schroeder, T V

    1995-01-01

    AND METHODS: We determined the incidence of postendarterectomy seizures related to haemodynamic impairment in terms of intraoperatively measured perfusion pressure in 151 patients undergoing 153 carotid endarterectomies. MAIN RESULTS: Cerebral perfusion pressure index (ICA/CCA pressure ratio...

  4. 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. 

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Caroline Alice Rickards

    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.

  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. 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.

  9. Procedure for Decellularization of Rat Livers in an Oscillating-pressure Perfusion Device.

    Science.gov (United States)

    Hillebrandt, Karl; Polenz, Dietrich; Butter, Antje; Tang, Peter; Reutzel-Selke, Anja; Andreou, Andreas; Napierala, Hendrik; Raschzok, Nathanael; Pratschke, Johann; Sauer, Igor M; Struecker, Benjamin

    2015-01-01

    Decellularization and recellularization of parenchymal organs may enable the generation of functional organs in vitro, and several protocols for rodent liver decellularization have already been published. We aimed to improve the decellularization process by construction of a proprietary perfusion device enabling selective perfusion via the portal vein and/or the hepatic artery. Furthermore, we sought to perform perfusion under oscillating surrounding pressure conditions to improve the homogeneity of decellularization. The homogeneity of perfusion decellularization has been an underestimated factor to date. During decellularization, areas within the organ that are poorly perfused may still contain cells, whereas the extracellular matrix (ECM) in well-perfused areas may already be affected by alkaline detergents. Oscillating pressure changes can mimic the intraabdominal pressure changes that occur during respiration to optimize microperfusion inside the liver. In the study presented here, decellularized rat liver matrices were analyzed by histological staining, DNA content analysis and corrosion casting. Perfusion via the hepatic artery showed more homogenous results than portal venous perfusion did. The application of oscillating pressure conditions improved the effectiveness of perfusion decellularization. Livers perfused via the hepatic artery and under oscillating pressure conditions showed the best results. The presented techniques for liver harvesting, cannulation and perfusion using our proprietary device enable sophisticated perfusion set-ups to improve decellularization and recellularization experiments in rat livers.

  10. 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.

  11. 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

  12. Neuroradiological findings in primary progressive aphasia: CT, MRI and cerebral perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Sinnatamby, R. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Antoun, N.A. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Freer, C.E.L. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Miles, K.A. [Dept. of Nuclear Medicine, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Hodges, J.R. [Dept. of Neurology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom)

    1996-04-01

    Primary progressive aphasia (PPA) is defined as progressive decline in language for 2 or more years with preservation of activities of daily living and general cognitive functions. Whereas the clinical features of this syndrome have been well documented, the neuroradiological findings have not been studied systematically. We studied 13 patients with PPA retrospectively: 10 underwent CT, 12 MRI and 12 cerebral perfusion studies using {sup 99m}Tc-HMPAO SPECT. CT and MR images were scored for focal atrophy by two independent assessors. Initial qualitative assessment of SPECT images was confirmed by quantitative analysis. CY was normal in 5 patients. Focal atrophy, affecting predominantly the left temporal lobe, was seen in 4 of 10 patients on CT, and 10 of 12 on MRI. Atrophy was localised primarily to the superior and middle temporal gyri on MRI. All 12 patients who underwent SPECT had unilateral temporal lobe perfusion defects, in 2 patients of whom MRI was normal. CT is relatively insensitive to focal abnormalities in PPA; MRI and SPECT are the imaging modalities of choice. MRI allows accurate, specific localisation of atrophy with the temporal neocortex. SPECT may reveal a functional decrease in cerebral perfusion prior to establishment of structural change. (orig.)

  13. 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.)

  14. Cerebral Perfusion Enhancing Interventions: A New Strategy for the Prevention of Alzheimer Dementia.

    Science.gov (United States)

    de la Torre, Jack C

    2016-09-01

    Cardiovascular and cerebrovascular diseases are major risk factors in the development of cognitive impairment and Alzheimer's disease (AD). These cardio-cerebral disorders promote a variety of vascular risk factors which in the presence of advancing age are prone to markedly reduce cerebral perfusion and create a neuronal energy crisis. Long-term hypoperfusion of the brain evolves mainly from cardiac structural pathology and brain vascular insufficiency. Brain hypoperfusion in the elderly is strongly associated with the development of mild cognitive impairment (MCI) and both conditions are presumed to be precursors of Alzheimer dementia. A therapeutic target to prevent or treat MCI and consequently reduce the incidence of AD aims to elevate cerebral perfusion using novel pharmacological agents. As reviewed here, the experimental pharmaca include the use of Rho kinase inhibitors, neurometabolic energy boosters, sirtuins and vascular growth factors. In addition, a compelling new technique in laser medicine called photobiomodulation is reviewed. Photobiomodulation is based on the use of low level laser therapy to stimulate mitochondrial energy production non-invasively in nerve cells. The use of novel pharmaca and photobiomodulation may become important tools in the treatment or prevention of cognitive decline that can lead to dementia. PMID:27324946

  15. Intraoperative imaging of cortical cerebral perfusion by time-resolved thermography and multivariate data analysis

    Science.gov (United States)

    Steiner, Gerald; Sobottka, Stephan B.; Koch, Edmund; Schackert, Gabriele; Kirsch, Matthias

    2011-01-01

    A new approach to cortical perfusion imaging is demonstrated using high-sensitivity thermography in conjunction with multivariate statistical data analysis. Local temperature changes caused by a cold bolus are imaged and transferred to a false color image. A cold bolus of 10 ml saline at ice temperature is injected systemically via a central venous access. During the injection, a sequence of 735 thermographic images are recorded within 2 min. The recorded data cube is subjected to a principal component analysis (PCA) to select slight changes of the cortical temperature caused by the cold bolus. PCA reveals that 11 s after injection the temperature of blood vessels is shortly decreased followed by an increase to the temperature before the cold bolus is injected. We demonstrate the potential of intraoperative thermography in combination with multivariate data analysis to image cortical cerebral perfusion without any markers. We provide the first in vivo application of multivariate thermographic imaging.

  16. 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...

  17. 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

  18. 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...

  19. Xueshuantong improves cerebral blood perfusion in elderly patients with lacunar infarction

    Institute of Scientific and Technical Information of China (English)

    Qifeng Gui; Yunmei Yang; Shihong Ying; Minming Zhang

    2013-01-01

    A total of 64 patients with acute lacunar infarction were enrolled within 24 hours of onset. The patients received conventional therapy (antiplatelet drugs and hypolipidemic drugs) alone or conventional therapy plus 450 mg Xueshuantong once a day. The main ingredient of the Xueshuantong lyophilized powder used for injection was Panax notoginseng saponins. Assessments were made at admission and at discharge using the National Institutes of Health Stroke Scale, the Activity of Daily Living and the Mini-Mental State Examination. Additionally, the relative cerebral blood flow, relative cerebral blood volume and relative mean transit time in the region of interest were calculated within 24 hours after the onset of lacunar infarction, using dynamic susceptibility contrast magnetic resonance perfusion imaging technology. Patients underwent a follow-up MRI scan after 4 weeks of treatment. There was an improvement in the Activity of Daily Living scores and a greater reduction in the scores on the National Institutes of Health Stroke Scale in the treatment group than in the control group. However, the Mini-Mental State Examination scores showed no significant differences after 4 weeks of treatment. Compared with the control group, the relative cerebral blood flow at discharge had increased and showed a greater improvement in the treatment group. Furthermore, there was a reduction in the relative mean transit time at discharge and the value was lower in the treatment group than in the control group. The experimental findings indicate that Xueshuantong treatment improves neurological deficits in elderly patients with lacunar infarction, and the mechanism may be related to increased cerebral perfusion.

  20. CT measurement of changes in cerebral perfusion in patients with asymptomatic carotid artery stenosis undergoing carotid stenting prior to cardiac surgery: "proof of principle"

    NARCIS (Netherlands)

    Heyden, J. Van der; Waaijer, A.; Wouter, E.S. Van; Neerven, D. van; Sonker, U.; Suttorp, M.J.; Bal, E.T.; Prokop, M.

    2011-01-01

    AIMS: To identify asymptomatic patients with impaired cerebral perfusion using CT perfusion (CTP) technique during staged carotid stenting (CAS) and cardiac surgery. METHODS AND RESULTS: This is a prospective, non-randomised study in 16 neurologically asymptomatic patients designed to analyse cerebr

  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-born neon......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...

  2. 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)

  3. Inhibitory effect of BIBN4096BS, CGRP(8-37), a CGRP antibody and an RNA-Spiegelmer on CGRP induced vasodilatation in the perfused and non-perfused rat middle cerebral artery

    DEFF Research Database (Denmark)

    Edvinsson, L; Nilsson, E; Jansen-Olesen, I

    2007-01-01

    -37 and BIBN4096BS) on CGRP-induced relaxations in the rat middle cerebral artery (MCA). Furthermore, the role of the endothelial barrier has been studied. EXPERIMENTAL APPROACH: We used the luminally perfused MCA in an arteriograph, pressurized to 85 mm Hg and myograph studies of isolated ring segments...... experiments, relaxation induced by alphaCGRP was prevented by the four CGRP blockers (CGRP8-37, BIBN4096BS, the CGRP antibody and NOX-C89.). In abluminal perfusion experiments, the relaxant response to alphaCGRP was prevented by these agents to a varying degree. Dilatation induced by abluminal application...... blockers significantly inhibited alphaCGRP induced relaxation but were also prevented from reaching the CGRP receptors by the arterial endothelium....

  4. 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

  5. Radiation dose reduction in cerebral CT perfusion imaging using iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Niesten, Joris M.; Schaaf, Irene C. van der; Riordan, Alan J.; Jong, Hugo W.A.M. de; Eijspaart, Daniel; Smit, Ewoud J.; Mali, Willem P.T.M.; Velthuis, Birgitta K. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Horsch, Alexander D. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Rijnstate Hospital, Department of Radiology, Arnhem (Netherlands)

    2014-02-15

    To investigate whether iterative reconstruction (IR) in cerebral CT perfusion (CTP) allows for 50 % dose reduction while maintaining image quality (IQ). A total of 48 CTP examinations were reconstructed into a standard dose (150 mAs) with filtered back projection (FBP) and half-dose (75 mAs) with two strengths of IR (middle and high). Objective IQ (quantitative perfusion values, contrast-to-noise ratio (CNR), penumbra, infarct area and penumbra/infarct (P/I) index) and subjective IQ (diagnostic IQ on a four-point Likert scale and overall IQ binomial) were compared among the reconstructions. Half-dose CTP with high IR level had, compared with standard dose with FBP, similar objective (grey matter cerebral blood volume (CBV) 4.4 versus 4.3 mL/100 g, CNR 1.59 versus 1.64 and P/I index 0.74 versus 0.73, respectively) and subjective diagnostic IQ (mean Likert scale 1.42 versus 1.49, respectively). The overall IQ in half-dose with high IR level was scored lower in 26-31 %. Half-dose with FBP and with the middle IR level were inferior to standard dose with FBP. With the use of IR in CTP imaging it is possible to examine patients with a half dose without significantly altering the objective and diagnostic IQ. The standard dose with FBP is still preferable in terms of subjective overall IQ in about one quarter of patients. (orig.)

  6. 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

  7. 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

  8. Application value of CT perfusion imaging with acetazolamide challenge test in the diagnosis of chronic cerebral insufficiency

    Institute of Scientific and Technical Information of China (English)

    高轩

    2014-01-01

    Objective To explore the CT perfusion imaging with acetazolamide(ACZ)challenge test in the diagnosis of chronic cerebral insufficiency.Methods 100 patients undergoing health examination in our hospital from Aug2009 to Feb 2011 were chosen,52 patients diagnosed as chronic cerebral insufficiency were defined as the case group,and the remaining 48 cases of healthy elderly people were defined as the control group.The brain CT

  9. Effect of Acupuncture Signal after Brachial Plexus Blockade on Cerebral Blood Perfusion and Brain Cell Function

    Institute of Scientific and Technical Information of China (English)

    任永功; 郭长春; 贾少微

    2003-01-01

    Objective: Using single photon emission computed tomography (SPECT) to observe the influence of the up-transmitting of acupuncture signal into the brain in health volunteers whose nerve trunk was blocked by anesthetics. Methods: Thirty-one healthy volunteers were divided into two groups, the control group of 20 cases, and the brachial plexus blockade (BPB) group of 11 cases, with supraclavicular BPB route adopted. With the control group 2 acupoints were randomly selected (Hegu and Quchi of both sides), while with the BPB group Hegu and Quchi of anesthetic arm side were selected. Siemens ECAM/ICON SPECT system was used to conduct brain imaging using double imaging assay before acupuncture and 99mTc-ECD imaging agent during acupuncture for cerebral perfusion. The data were quantitatively analyzed by blood functional changing rate (BFCR%) mathematics model. Results: Before acupuncture, the control and BPB groups showed insignificant change by SPECT, but after electro-acupuncture (EA), the control group displayed improved motor and sensory cortex excitability in basal nuclei, contra-lateral thalamus, parietal and frontal lobe; while BPB group was characterized with reduction of the blood perfusion and cell function of contra-lateral thalamus of anesthetized arm. The difference between the two groups was significant (P<0.01). Conclusion: (1) After BPB, the up-transmitting of the acupuncture signal via upper limb into the brain, and its strength was impaired or blocked; (2) After BPB, the effect of acupuncture on cerebral perfusion and brain cell function of contra-lateral thalamus was impaired or blocked.

  10. 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.)

  11. Real-time ultrasound perfusion imaging in acute stroke: assessment of cerebral perfusion deficits related to arterial recanalization.

    Science.gov (United States)

    Bolognese, Manuel; Artemis, Dimitrios; Alonso, Angelika; Hennerici, Michael G; Meairs, Stephan; Kern, Rolf

    2013-05-01

    We investigated whether real-time ultrasound perfusion imaging (rt-UPI) is able to detect perfusion changes related to arterial recanalization in the acute phase of middle cerebral artery (MCA) stroke. Twenty-four patients with acute territorial MCA stroke were examined with rt-UPI and transcranial color-coded duplex ultrasound (TCCD). Ultrasound studies were consecutively performed within 24 h and 72-96 h after stroke onset. Real-time UPI parameters of bolus kinetics (time to peak, rt-TTP) and of refill kinetics (plateau A and slope β of the exponential replenishment curve) were calculated from regions of interest of ischemic versus normal brain tissue; these parameters were compared between early and follow-up examinations in patients who recanalized. At the early examination, there was a delay of rt-TTP in patients with MCA occlusion (rt-TTP [s]: 13.09 ± 3.21 vs. 10.16 ± 2.6; p = 0.01) and a lower value of the refill parameter β (β [1/s]: 0.62 ± 0.34 vs. 1.09 ± 0.58; p = 0.01) in ischemic compared with normal brain tissue, whereas there were no differences of the parameters A and Axβ. At follow-up, the delay of rt-TTP was reversible once recanalization of an underlying MCA obstruction was demonstrated: rt-TTP [s], 13.09 ± 3.21 at 24 h versus 10.95 ± 1.5 at 72-96 h (p = 0.03). Correspondingly, β showed a higher slope than at the first examination: β [1/s]: 0.55 ± 0.29 at 24 h versus 0.71 ± 0.27 at 72-96 h (p = 0.04). We conclude that real-time UPI can detect hemodynamic impairment in acute MCA occlusion and subsequent improvement following arterial recanalization. This offers the chance for bedside monitoring of the hemodynamic compromise (e.g. during therapeutic interventions such as systemic thrombolysis).

  12. 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.

  13. 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.)

  14. 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.)

  15. Acute and chronic head-down tail suspension diminishes cerebral perfusion in rats

    Science.gov (United States)

    Wilkerson, M. Keith; Colleran, Patrick N.; Delp, Michael D.

    2002-01-01

    The purpose of this study was to test the hypothesis that regional brain blood flow and vascular resistance are altered by acute and chronic head-down tail suspension (HDT). Regional cerebral blood flow, arterial pressure, heart rate, and vascular resistance were measured in a group of control rats during normal standing and following 10 min of HDT and in two other groups of rats after 7 and 28 days of HDT. Heart rate was not different among conditions, whereas mean arterial pressure was elevated at 10 min of HDT relative to the other conditions. Total brain blood flow was reduced from that during standing by 48, 24, and 27% following 10 min and 7 and 28 days of HDT, respectively. Regional blood flows to all cerebral tissues and the eyes were reduced with 10 min of HDT and remained lower in the eye, olfactory bulbs, left and right cerebrum, thalamic region, and the midbrain with 7 and 28 days of HDT. Total brain vascular resistance was 116, 44, and 38% greater following 10 min and 7 and 28 days of HDT, respectively, relative to that during control standing. Vascular resistance was elevated in all cerebral regions with 10 min of HDT and remained higher than control levels in most brain regions. These results demonstrate that HDT results in chronic elevations in total and regional cerebral vascular resistance, and this may be the underlying stimulus for the HDT-induced smooth muscle hypertrophy of cerebral resistance arteries.

  16. Methodological NMR imaging developments to measure cerebral perfusion; Developpements methodologiques en IRM pour la mesure de perfusion cerebrale

    Energy Technology Data Exchange (ETDEWEB)

    Pannetier, N.

    2010-12-15

    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)

  17. Pressure and oxygen debt on bypass - potential quality markers of perfusion?

    Science.gov (United States)

    Poullis, Mike; Palmer, K; Al-Rawi, O; Johnson, I; Ridgeway, T

    2012-05-01

    No markers of quality of perfusion pressure and oxygen delivery during cardiopulmonary bypass (CPB), to complement rewarming rate, maximum temperature on rewarming, lowest haematocrit, and blood glucose, exist. Using the electronic acquisition of blood pressure on bypass (JOCAP system), the percentage of time perfusion pressure was below 30, 40, 50, 60 and 70 mmHg, average deviance, confidence interval, median, mode, standard deviation, variance, and average, maximum and cumulative oxygen debt were calculated. Numerous different readouts of achievement of maintenance of constant pressure on bypass and oxygen debt are now easily achievable with perfusion electronic data management systems. Mean, median, and mode offer poor discrimination of pressure control during CPB. Percentage of time perfusion pressure was below 30, 40, 50, 60 and 70 mmHg, average deviance, confidence interval, and standard deviation all have discriminatory power, but need clinical correlation for their significance. A composite score involving non-pressure readouts (e.g. oxygen delivery, arterial and venous saturations, and flow rates) may need to be integrated into any perfusion quality marker. Assessment of adequacy of constant perfusion pressure and oxygen delivery may allow the scientific evaluation of pressure and oxygen delivery on bypass for patients to be compared accurately. Currently, in studies involving CPB, blood pressure targets are stated with no quantitative assessment of adequacy of achievement of these targets. Electronic data monitoring during cardiopulmonary bypass, when correlated with clinical outcome, may help to provide a marker of quality of perfusion pressure during CPB and may, indeed, allow patient-specific perfusion pressure strategies to be developed.

  18. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Won; Kim, Yu Kyeong; Lee, Sang Mi; Eo, Jae Sun; Oh, Chang Wan; Lee, Won Woo; Paeng, Jin Chul; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2008-08-15

    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

  20. 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.)

  1. 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.)

  2. 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%....

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

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    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.

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

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    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

  5. A brain stress test: Cerebral perfusion during memory encoding in mild cognitive impairment

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    Long Xie

    2016-01-01

    Full Text Available Arterial spin labeled perfusion magnetic resonance imaging (ASL MRI provides non-invasive quantification of cerebral blood flow, which can be used as a biomarker of brain function due to the tight coupling between cerebral blood flow (CBF and brain metabolism. A growing body of literature suggests that regional CBF is altered in neurodegenerative diseases. Here we examined ASL MRI CBF in subjects with amnestic mild cognitive impairment (n = 65 and cognitively normal healthy controls (n = 62, both at rest and during performance of a memory-encoding task. As compared to rest, task-enhanced ASL MRI improved group discrimination, which supports the notion that physiologic measures during a cognitive challenge, or “stress test”, may increase the ability to detect subtle functional changes in early disease stages. Further, logistic regression analysis demonstrated that ASL MRI and concomitantly acquired structural MRI provide complementary information of disease status. The current findings support the potential utility of task-enhanced ASL MRI as a biomarker in early Alzheimer's disease.

  6. 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

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

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    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

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

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    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

  9. Quantitative Measurement of Cerebral Perfusion with Intravoxel Incoherent Motion in Acute Ischemia Stroke: Initial Clinical Experience

    Institute of Scientific and Technical Information of China (English)

    Li-Bao Hu; Nan Hong; Wen-Zhen Zhu

    2015-01-01

    Background:Intravoxel incoherent motion (IVIM) has the potential to provide both diffusion and perfusion information without an exogenous contrast agent,its application for the brain is promising,however,feasibility studies on this are relatively scarce.The aim of this study is to assess the feasibility of IVIM perfusion in patients with acute ischemic stroke (AIS).Methods:Patients with suspected AIS were examined by magnetic resonance imaging within 24 h of symptom onset.Fifteen patients (mean age was 68.7 ± 8.0 years) who underwent arterial spin labeling (ASL) and diffusion-weighted imaging (DWI) were identified as having AIS with ischemic penumbra were enrolled,where ischemic penumbra referred to the mismatch areas of ASL and DWI.Eleven different b-values were applied in the biexponential model.Regions of interest were selected in ischemic penumbras and contralateral normal brain regions.Fast apparent diffusion coefficients (ADCs) and ASL cerebral blood flow (CBF) were measured.The paired t-test was applied to compare ASL CBF,fast ADC,and slow ADC measurements between ischemic penumbras and contralateral normal brain regions.Linear regression and Pearson's correlation were used to evaluate the correlations among quantitative results.Results:The fast ADCs and ASL CBFs of ischemic penumbras were significantly lower than those of the contralateral normal brain regions (1.93 ± 0.78 μm2/ms vs.3.97 ± 2.49 μm2/ms,P =0.007;13.5 ± 4.5 ml· 100 g-1 ·min-1 vs.29.1 ± 12.7 ml·100 g-1 ·min-1,P < 0.001,respectively).No significant difference was observed in slow ADCs between ischemic penumbras and contralateral normal brain regions (0.203 ± 0.090 μm2/ms vs.0.198 ± 0.100 μm2/ms,P =0.451).Compared with contralateral normal brain regions,both CBFs and fast ADCs decreased in ischemic penumbras while slow ADCs remained the same.A significant correlation was detected between fast ADCs and ASL CBFs (r =0.416,P < 0.05).No statistically significant correlation was

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

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    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.)

  11. Effect of large decompressive craniectomy combined with vascular reconstruction on cerebral perfusion in patients with severe brain injury

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    Liang-zhen HUANG

    2015-11-01

    Full Text Available Objective To compare the efficacies of large decompressive craniectomy combined with vascular reconstruction and traditional decompressive craniectomy in treatment of severe brain injury. Methods Forty-eight patients with severe brain injury, which was dominated by brain contusion to the frontoparietal lobes, admitted to our hospital from March 2012 to March 2014 were divided equally into experimental group and control group. The patients in the experimental group underwent large decompressive craniectomy combined with vascular reconstruction, and the patients in the control group received traditional decompressive craniectomy. The hemodynamic changes including cerebral blood flow (CBF, cerebral blood volume (CBV, mean transit time (MTT, time to peak (TTP and the ratios of these values (rCBF, rCBV, rMTT and rTTP on two sides were observed by CT perfusion imaging, and the Glasgow outcome score (GOS was analyzed 6 months after operation. Results The CBF and CBV scores in experimental group were higher than those in the control group at 1 week and 1 month after the operation (P0.05. The rate of satisfactory recovery (including good recovery and moderate disability was higher in the experimental group than in the control group, while the rate of poor recovery (including severe disability, vegetative state and death was lower in the experimental group than in the control group (P<0.05. Conclusion The large decompressive craniectomy combined with vascular reconstruction can not only decrease the intracranial pressure, but also recover the blood supply of brain, thus deserving the clinical application and popularization. DOI: 10.11855/j.issn.0577-7402.2015.11.15

  12. Similar cerebral protective effectiveness of antegrade and retrograde cerebral perfusion during deep hypothermic circulatory arrest in aortic surgery: a meta-analysis of 7023 patients.

    Science.gov (United States)

    Guo, Shasha; Sun, Yanhua; Ji, Bingyang; Liu, Jinping; Wang, Guyan; Zheng, Zhe

    2015-04-01

    In aortic arch surgery, deep hypothermic circulatory arrest (DHCA) combined with cerebral perfusion is employed worldwide as a routine practice. Even though antegrade cerebral perfusion (ACP) is more widely used than retrograde cerebral perfusion (RCP), the difference in benefit and risk between ACP and RCP during DHCA is uncertain. The purpose of this meta-analysis is to compare neurologic outcomes and early mortality between ACP and RCP in patients who underwent aortic surgery during DHCA. PubMed, EMBASE, and the Cochrane Library were searched using the key words "antegrade," "retrograde," "cerebral perfusion," "cardiopulmonary bypass," "extracorporeal circulation," and "cardiac surgery" for studies reporting on clinical endpoints including early mortality, stroke, temporary neurologic dysfunction (TND), and permanent neurologic dysfunction (PND) in aortic surgery requiring DHCA with ACP or RCP. Heterogeneity was analyzed with the Cochrane Q statistic and I(2) statistic. Publication bias was tested with Begg's funnel plot and Egger's test. Thirty-four studies were included in this meta-analysis, with 4262 patients undergoing DHCA + ACP and 2761 undergoing DHCA + RCP. The overall pooled relative risk for TND was 0.722 (95% CI = [0.579, 0.900]), and the z-score for overall effect was 2.9 (P = 0.004). There was low heterogeneity (I(2) = 18.7%). The analysis showed that patients undergoing DHCA + ACP had better outcomes than those undergoing DHCA + RCP in terms of TND, while there were no significant differences between groups in terms of PND, stroke, and early mortality. This meta-analysis indicates that DHCA + ACP has an advantage over DHCA + RCP in terms of TND, while the two methods show similar results in terms of PND, early mortality, and stroke.

  13. 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

  14. Clinical Neuroimaging of cerebral ischemia

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    Nakagawara, Jyoji [Nakamura Memorial Hospital, Sapporo (Japan)

    1999-06-01

    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.)

  15. Patient directed perfusion pressure on bypass, an analogy from electrical engineering--a new concept.

    Science.gov (United States)

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-03-01

    Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual's resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept.

  16. Patient Directed Perfusion Pressure on Bypass, an Analogy from Electrical Engineering—A New Concept

    Science.gov (United States)

    Warwick, Richard; Poole, Robert; Palmer, Kenneth; Johnson, Ian; Poullis, Michael

    2010-01-01

    Abstract: Organ ischemia, particularly mesenteric and renal, can occur despite a seemingly adequate perfusion flow and pressure during a period of cardiopulmonary bypass. The blood pressure to run bypass at remains a contentious issue. We present the concept that perfusion pressure during cardiopulmonary bypass should be patient specific, depending on an individual’s resting pre-procedural blood pressure. Four simulated arterial traces with variable morphology, but identical systolic and diastolic blood pressures, were analyzed to calculate the medical mean, arithmetic mean, and root mean square of the blood pressure tracing. Using the standard medical formula for calculation of mean blood pressure, you can potentially underestimate perfusion pressure by 12 mmHg in a normotensive subject. The root mean square pressure calculates the equivalent non pulsatile pressure that will deliver the same hydraulic power to the circulation as its pulsatile equivalent. Patient specific perfusion pressures, calculated via root mean square may potentially help reduce the incidence of organ ischemia during cardiopulmonary bypass. Clinical trials are needed to confirm or refute this concept. PMID:20437793

  17. Perfusion and diffusion MRI study detecting CBF disturbance and edema formation in the acute phase of cerebral contusion

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    Kawamata, Tatsuro; Aoyama, Naoki; Mori, Tatsuro; Maeda, Takeshi; Katayama, Yoichi [Nihon Univ., Tokyo (Japan). School of Medicine

    1998-12-01

    In order to clarify the mechanisms underlying cerebral contusion-induced CBF disturbance and edema formation, echoplanar diffusion and perfusion images were obtained in the patients with cerebral contusion. In the acute phase within 48 hours post-trauma, the apparent diffusion coefficient (ADC) showed various levels with a tendency to increase in the central area of contusion (ADC ratio=1.06{+-}0.21). In contrast, the ADC was significantly reduced in the peripheral area of contusion (ADC ratio=0.87{+-}0.16). The ADC at 2 weeks post-trauma increased both in the central (ADC ratio=1.16{+-}0.26) and the peripheral area of contusion (ADC ratio=1.10{+-}0.26, p<0.05), as compared to those within 48 hours post-trauma. The perfusion images showed a wide spread CBF depression extending beyond the area of contusion observed on the T1 and T2 weighted images. These results indicate that; in the early phase of contusion-induced edema formation, cytotoxic edema is predominant, especially in the peripheral area of contusion, and vasogenic edema appears thereafter. The CBF depression may contribute such cytotoxic edema formation in the surrounding area of cerebral contusion. It is concluded that echo-planar diffusion and perfusion images are excellent technique to investigate the evolution of CBF disturbance and edema formation following traumatic brain injury. (author)

  18. 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;

    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 obtained......Hg (SD 8.7). As compared to the intra-arterial blood pressure the BTEP was found to lie close to the mean blood pressure in normal subjects as well as in hypertensive subjects. The present data indicate that the skin perfusion pressure on the legs can be measured by the rapid photo-electric technique...

  19. 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

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    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

  20. Dynamics of cerebral tissue injury and perfusion after temporary hypoxia-ischemia in the rat - Evidence for region-specific sensitivity and delayed damage

    NARCIS (Netherlands)

    Dijkhuizen, RM; Knollema, S; van der Worp, H. Bart; Ter Horst, GJ; De Wildt, DJ; van der Sprenkel, JWB; Tulleken, KAF; Nicolay, K

    1998-01-01

    Background and Purpose-Selective regional sensitivity and delayed damage in cerebral ischemia provide opportunities for directed and late therapy for stroke. Our aim was to characterize the spatial and temporal profile of ischemia-induced changes in cerebral perfusion and tissue status, with the use

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Is correction necessary when clinically determining quantitative cerebral perfusion parameters from multi-slice dynamic susceptibility contrast MR studies?

    Science.gov (United States)

    Salluzzi, M.; Frayne, R.; Smith, M. R.

    2006-01-01

    Several groups have modified the standard singular value decomposition (SVD) algorithm to produce delay-insensitive cerebral blood flow (CBF) estimates from dynamic susceptibility contrast (DSC) perfusion studies. However, new dependences of CBF estimates on bolus arrival times and slice position in multi-slice studies have been recently recognized. These conflicting findings can be reconciled by accounting for several experimental and algorithmic factors. Using simulation and clinical studies, the non-simultaneous measurement of arterial and tissue concentration curves (relative slice position) in a multi-slice study is shown to affect time-related perfusion parameters, e.g. arterial-tissue-delay measurements. However, the current clinical impact of relative slice position on amplitude-related perfusion parameters, e.g. CBF, can be expected to be small unless any of the following conditions are present individually or in combination: (a) high concentration curve signal-to-noise ratios, (b) small tissue mean transit times, (c) narrow arterial input functions or (d) low temporal resolution of the DSC image sequence. Recent improvements in magnetic resonance (MR) technology can easily be expected to lead to scenarios where these effects become increasingly important sources of inaccuracy for all perfusion parameter estimates. We show that using Fourier interpolated (high temporal resolution) residue functions reduces the systematic error of the perfusion parameters obtained from multi-slice studies. Preliminary results associated with this paper were presented at ISMRM 12th Scientific Meeting and Exhibition, Kyoto, Japan, 2004.

  3. Accuracy of CT cerebral perfusion in predicting infarct in the emergency department: lesion characterization on CT perfusion based on commercially available software.

    Science.gov (United States)

    Ho, Chang Y; Hussain, Sajjad; Alam, Tariq; Ahmad, Iftikhar; Wu, Isaac C; O'Neill, Darren P

    2013-06-01

    This study aims to assess the diagnostic accuracy of a single vendor commercially available CT perfusion (CTP) software in predicting stroke. A retrospective analysis on patients presenting with stroke-like symptoms within 6 h with CTP and diffusion-weighted imaging (DWI) was performed. Lesion maps, which overlays areas of computer-detected abnormally elevated mean transit time (MTT) and decreased cerebral blood volume (CBV), were assessed from a commercially available software package and compared to qualitative interpretation of color maps. Using DWI as the gold standard, parameters of diagnostic accuracy were calculated. Point biserial correlation was performed to assess for relationship of lesion size to a true positive result. Sixty-five patients (41 females and 24 males, age range 22-92 years, mean 57) were included in the study. Twenty-two (34 %) had infarcts on DWI. Sensitivity (83 vs. 70 %), specificity (21 vs. 69 %), negative predictive value (77 vs. 84 %), and positive predictive value (29 vs. 50 %) for lesion maps were contrasted to qualitative interpretation of perfusion color maps, respectively. By using the lesion maps to exclude lesions detected qualitatively on color maps, specificity improved (80 %). Point biserial correlation for computer-generated lesions (R pb = 0.46, p perfusion color map assessment, the lesion maps can help improve specificity.

  4. Dose reduction in dynamic perfusion CT of the brain: effects of the scan frequency on measurements of cerebral blood flow, cerebral blood volume, and mean transit time

    Energy Technology Data Exchange (ETDEWEB)

    Wiesmann, Martin [University of Munich, Department of Neuroradiology, Muenchen (Germany); Klinikum der Universitaet Muenchen - Grosshadern, Abteilung fuer Neuroradiologie, Muenchen (Germany); Berg, Scott; Stoeckelhuber, B.M. [University of Luebeck, Department of Radiology, Luebeck (Germany); Bohner, G.; Klingebiel, R. [University Medicine Berlin, Department of Neuroradiology, Charite, Berlin (Germany); Schoepf, V.; Yousry, I.; Linn, J. [University of Munich, Department of Neuroradiology, Muenchen (Germany); Missler, U. [Evangelisches Krankenhaus Duisburg-Nord, Department of Neuroradiology, Duisburg (Germany)

    2008-12-15

    The influence of the frequency of computed tomography (CT) image acquistion on the diagnostic quality of dynamic perfusion CT (PCT) studies of the brain was investigated. Eight patients with clinically suspected acute ischemia of one hemisphere underwent PCT, performed on average 3.4 h after the onset of symptoms. Sixty consecutive images per slice were obtained with individual CT images obtained at a temporal resolution of two images per second. Eight additional data sets were reconstructed with temporal resolutions ranging from one image per second to one image per 5 s. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) measurements were performed in identical regions of interest. Two neuroradiologists evaluated the PCT images visually to identify areas of abnormal perfusion. Perfusion images created up to a temporal resolution of one image per 3 s were rated to be diagnostically equal to the original data. Even at one image per 4 s, all areas of infarction were identified. Quantitative differences of CBF, CBV and MTT measurements were {<=}10% up to one image per 3 s. For PCT of the brain, temporal resolution can be reduced to one image per 3 s without significant compromise in image quality. This significantly reduces the radiation dose of the patient. (orig.)

  5. Relationship between blood pressure, cerebral electrical activity, cerebral fractional oxygen extraction, and peripheral blood flow in very low birth weight newborn infants.

    Science.gov (United States)

    Victor, Suresh; Marson, Anthony G; Appleton, Richard E; Beirne, Margaret; Weindling, A Michael

    2006-02-01

    There is uncertainty about the level of systemic blood pressure required to maintain adequate cerebral oxygen delivery and organ integrity. This prospective, observational study on 35 very low birth weight infants aimed to determine the mean blood pressure (MBP) below which cerebral electrical activity, peripheral blood flow (PBF), and cerebral fractional oxygen extraction (CFOE) are abnormal. Digital EEG, recorded every day on the first 4 d after birth, were analyzed a) by automatic spectral analysis, b) by manual measurement of interburst interval, and c) qualitatively. CFOE and PBF measurements were performed using near-infrared spectroscopy and venous occlusion. MBP was measured using arterial catheters. The median (range) of MBP recorded was 32 mm Hg (16-46). The EEG became abnormal at MBP levels below 23 mm Hg: a) the relative power of the delta (0.5-3.5 Hz) frequency band was decreased, b) interburst intervals were prolonged, and c) all four qualitatively abnormal EEG (low amplitude and prolonged interburst intervals) from four different patients were recorded below this MBP level. The only abnormally high CFOE was measured at MBP of 20 mm Hg. PBF decreased at MBP levels between 23 and 33 mm Hg. None of the infants in this study developed cystic periventricular leukomalacia. One infant (MBP, 22 mm Hg) developed ventricular dilatation after intraventricular hemorrhage. The EEG and CFOE remained normal at MBP levels above 23 mm Hg. It would appear that cerebral perfusion is probably maintained at MBP levels above 23 mm Hg. PMID:16439599

  6. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mendrik, Adrienne M; Van Ginneken, Bram; Viergever, Max A [Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Vonken, Evert-jan; De Jong, Hugo W; Riordan, Alan; Van Seeters, Tom; Smit, Ewoud J; Prokop, Mathias, E-mail: a.m.mendrik@gmail.com [Radiology Department, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

    2011-07-07

    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

  8. 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

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

    Science.gov (United States)

    Mendrik, Adriënne M.; Vonken, Evert-jan; van Ginneken, Bram; de Jong, Hugo W.; Riordan, Alan; van Seeters, Tom; Smit, Ewoud J.; Viergever, Max A.; Prokop, Mathias

    2011-07-01

    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

  10. Optical bedside monitoring of cerebral perfusion: technological and methodological advances applied in a study on acute ischemic stroke

    Science.gov (United States)

    Steinkellner, Oliver; Gruber, Clemens; Wabnitz, Heidrun; Jelzow, Alexander; Steinbrink, Jens; Fiebach, Jochen B.; MacDonald, Rainer; Obrig, Hellmuth

    2010-11-01

    We present results of a clinical study on bedside perfusion monitoring of the human brain by optical bolus tracking. We measure the kinetics of the contrast agent indocyanine green using time-domain near-IR spectroscopy (tdNIRS) in 10 patients suffering from acute unilateral ischemic stroke. In all patients, a delay of the bolus over the affected when compared to the unaffected hemisphere is found (mean: 1.5 s, range: 0.2 s to 5.2 s). A portable time-domain near-IR reflectometer is optimized and approved for clinical studies. Data analysis based on statistical moments of time-of-flight distributions of diffusely reflected photons enables high sensitivity to intracerebral changes in bolus kinetics. Since the second centralized moment, variance, is preferentially sensitive to deep absorption changes, it provides a suitable representation of the cerebral signals relevant for perfusion monitoring in stroke. We show that variance-based bolus tracking is also less susceptible to motion artifacts, which often occur in severely affected patients. We present data that clearly manifest the applicability of the tdNIRS approach to assess cerebral perfusion in acute stroke patients at the bedside. This may be of high relevance to its introduction as a monitoring tool on stroke units.

  11. 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

  12. 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.)

  13. 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.

  14. Early whole-brain CT perfusion for detection of patients at risk for delayed cerebral ischemia after subarachnoid hemorrhage.

    Science.gov (United States)

    Malinova, Vesna; Dolatowski, Karoline; Schramm, Peter; Moerer, Onnen; Rohde, Veit; Mielke, Dorothee

    2016-07-01

    OBJECT This prospective study investigated the role of whole-brain CT perfusion (CTP) studies in the identification of patients at risk for delayed ischemic neurological deficits (DIND) and of tissue at risk for delayed cerebral infarction (DCI). METHODS Forty-three patients with aneurysmal subarachnoid hemorrhage (aSAH) were included in this study. A CTP study was routinely performed in the early phase (Day 3). The CTP study was repeated in cases of transcranial Doppler sonography (TCD)-measured blood flow velocity (BFV) increase of > 50 cm/sec within 24 hours and/or on Day 7 in patients who were intubated/sedated. RESULTS Early CTP studies revealed perfusion deficits in 14 patients, of whom 10 patients (72%) developed DIND, and 6 of these 10 patients (60%) had DCI. Three of the 14 patients (21%) with early perfusion deficits developed DCI without having had DIND, and the remaining patient (7%) had neither DIND nor DCI. There was a statistically significant correlation between early perfusion deficits and occurrence of DIND and DCI (p 50 cm/sec within 24 hours, revealing a perfusion deficit in 3 of them (38%). Two of the 3 patients (67%) developed DCI without preceding DIND and 1 patient (33%) had DIND without DCI. In 4 of the 7 patients (57%) who were sedated and/or comatose, additional CTP studies on Day 7 showed perfusion deficits. All 4 patients developed DCI. CONCLUSIONS Whole-brain CTP on Day 3 after aSAH allows early and reliable identification of patients at risk for DIND and tissue at risk for DCI. Additional CTP investigations, guided by TCD-measured BFV increase or persisting coma, do not contribute to information gain.

  15. Perfusion and diffusion imaging in acute focal cerebral ischemia: Temporal vs. spatial resolution

    Science.gov (United States)

    Bardutzky, Juergen; Shen, Qiang; Bouley, James; Sotak, Christopher H.; Duong, Timothy Q.; Fisher, Marc

    2010-01-01

    High-resolution diffusion- (DWI) and perfusion-weighted (PWI) imaging may provide substantial benefits in accurate delineation of normal, ischemic, and at-risk tissue. We compared the capability of low (400 × 400 µm2) and high (200 × 200 µm2) spatial resolution imaging in characterizing the spatiotemporal evolution of the ischemic lesion in a permanent middle artery occlusion (MCAO) model in rats. Serial measurements of cerebral blood flow (CBF) and the apparent diffusion coefficient (ADC) were performed. Lesion volumes were calculated by using viability thresholds or by visual inspection, and correlated with infarct volume defined by TTC staining at 24 h after MCAO. At the very early phase of ischemia, high-resolution resulted in a significantly larger ADC-derived lesion volume and a smaller PWI/DWI mismatch. At 3 h after MCAO, ADC and CBF lesions showed similar robust correlations with TTC-defined infarct volumes for both groups using previously established thresholds. When lesions were determined visually, low-resolution resulted in a substantial overestimation of TTC-defined infarct volume and a lower inter-observer reliability (r = 0.75), whereas high-resolution produced an excellent correlation with TTC-defined infarct volume and inter-observer reliability (r = 0.96). In conclusion, high-resolution MRI resulted in substantial temporal averaging of the ischemic lesion during the early phase, but was clearly superior in visual determination of final infarct size. Low-resolution reasonably evaluated the temporal and spatial evolution of ischemia when thresholds were used. PMID:15862529

  16. 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

  17. 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.

  18. Comparison of cerebral blood volume and permeability in preoperative grading of intracranial glioma using CT perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Bei; Ling, Hua Wei; Chen, Ke Min [Shanghai Jiaotong University, Department of Radiology, Ruijin Hospital, School of Medicine, Shanghai (China); Jiang, Hong [Shanghai Jiaotong University, Department of Pathology, Ruijin Hospital, School of Medicine, Shanghai (China); Zhu, Yan Bo [Shanghai Jiaotong University, Department of Neurosurgery, Ruijin Hospital, School of Medicine, Shanghai (China)

    2006-10-15

    Regional cerebral blood volume (rCBV) and permeability surfaces (rPS) permit in vivo assessment of glioma microvasculature, which provides quite important pathophysiological information in grading gliomas. The aim of our study was to simultaneously examine rCBV and rPS in glioma patients to determine their correlation with histological grade using CT perfusion imaging. A total of 22 patients with gliomas underwent multislice CT perfusion imaging preoperatively. Low-grade and high-grade groups were categorized corresponding to WHO grade II gliomas and WHO grade III or IV gliomas, respectively, as determined by histopathological examination. rCBVs and rPSs were obtained from regions of maximal abnormality in tumor parenchyma on CBV and PS color perfusion maps. Perfusion parameters were compared using the Kruskal-Wallis test in order to evaluate the differences in relation to tumor grade. The Pearson coefficients of rCBV and rPS for each tumor grade were assessed using SPSS 13.0 software. (orig.)

  19. Differences in cerebral perfusion deficits in mild traumatic brain injury and depression using single photon emission computed tomography

    Directory of Open Access Journals (Sweden)

    Kristoffer eRomero

    2014-08-01

    Full Text Available Background: Numerous studies have shown decreased perfusion in the prefrontal cortex following mild traumatic brain injury (mTBI. However, similar hypoperfusion can also be observed in depression. Given the high prevalence of depressive symptoms following mTBI, it is unclear to what extent depression influences hypoperfusion in TBI.Methods: Mild TBI patients without depressive symptoms (mTBI-noD, n = 39, TBI patients with depressive symptoms (mTBI-D, n = 13, and 15 patients with major depressive disorder, but no TBI (MDD were given 99-m T-ECD SPECT scans within 2 weeks of injury. All subjects completed tests of information processing speed, complex attention, and executive functioning, and a self-report questionnaire measuring symptoms of psychological distress. Between group comparisons of quantified SPECT perfusion were undertaken, using univariate and multivariate (partial least squares analyses.Results: mTBI-D and mTBI-noD groups did not differ in terms of cerebral perfusion. However, patients with MDD showed hypoperfusion in several frontal (orbitofrontal, middle frontal, and superior frontal cortex, superior temporal, and posterior cingulate regions. The mTBI-D group showed poorer performance on a measure of complex attention and working memory, compared to both the mTBI-noD and MDD groups.Conclusions: These results suggest that depressive symptoms do not affect SPECT perfusion in the sub-acute phase following a mild TBI. Conversely, MDD is associated with hypoperfusion primarily in frontal regions.

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

    Directory of Open Access Journals (Sweden)

    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. 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

  2. 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

  3. Pressure- and flow-controlled media perfusion differently modify vascular mechanics in lung decellularization.

    Science.gov (United States)

    da Palma, Renata K; Campillo, Noelia; Uriarte, Juan J; Oliveira, Luis V F; Navajas, Daniel; Farré, Ramon

    2015-09-01

    Organ biofabrication is a potential future alternative for obtaining viable organs for transplantation. Achieving intact scaffolds to be recellularized is a key step in lung bioengineering. Perfusion of decellularizing media through the pulmonary artery has shown to be effective. How vascular perfusion pressure and flow vary throughout lung decellularization, which is not well known, is important for optimizing the process (minimizing time) while ensuring scaffold integrity (no barotrauma). This work was aimed at characterizing the pressure/flow relationship at the pulmonary vasculature and at how effective vascular resistance depends on pressure- and flow-controlled variables when applying different methods of media perfusion for lung decellularization. Lungs from 43 healthy mice (C57BL/6; 7-8 weeks old) were investigated. After excision and tracheal cannulation, lungs were inflated at 10 cmH2O airway pressure and subjected to conventional decellularization with a solution of 1% sodium dodecyl sulfate (SDS). Pressure (PPA) and flow (V'PA) at the pulmonary artery were continuously measured. Decellularization media was perfused through the pulmonary artery: (a) at constant PPA=20 cmH2O or (b) at constant V'PA=0.5 and 0.2 ml/min. Effective vascular resistance was computed as Rv=PPA/V'PA. Rv (in cmH2O/(ml/min)); mean±SE) considerably varied throughout lung decellularization, particularly for pressure-controlled perfusion (from 29.1±3.0 in baseline to a maximum of 664.1±164.3 (pperfusion (from 49.9±3.3 and 79.5±5.1 in baseline to a maximum of 114.4±13.9 and 211.7±70.5 (pperfusion mechanics throughout decellularization provides information relevant for optimizing the process time while ensuring that vascular pressure is kept within a safety range to preserve the organ scaffold integrity.

  4. 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.

  5. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kloska, Stephan P.; Fischer, Tobias; Fischbach, Roman; Heindel, Walter [University of Muenster, Department of Clinical Radiology, Muenster (Germany); Nabavi, Darius G.; Dittrich, Ralf; Ringelstein, E.B. [University of Muenster, Department of Neurology, Muenster (Germany); Ditt, Hendrik; Klotz, Ernst [Siemens AG, Medical Solutions, Forchheim (Germany)

    2007-09-15

    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.)

  7. 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.

  8. 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.)

  9. 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)

  10. User friendly analysis of MR investigations of the cerebral perfusion: Windows {sup trademark} -based image processing; Benutzerfreundliche Auswertung von MR-Untersuchungen der zerebralen Perfusion: Windows {sup trademark} -basierte Bildverarbeitung

    Energy Technology Data Exchange (ETDEWEB)

    Wittsack, H.J.; Moedder, U. [Inst. fuer Diagnostische Radiologie, Univ. Duesseldorf (Germany); Ritzl, A. [Inst. fuer Medizin, Forschungszentrum Juelich (Germany)

    2002-06-01

    Purpose: Quick and user-friendly analysis of perfusion and diffusion weighted MRI by means of interactive computer software. Method: A Windows {sup trademark} -based software was developed for analysis of perfusion (PWI) and diffusion (DWI) MR imaging. The computer program was developed in the programming language C++ using optimized algorithms, so that a high computing speed on Win95/98/NT systems is achieved. The established SVD algorithms of Oestergaard et al. for quantitative perfusion analysis were implemented. Results: Perfusion parameter maps of the cerebral blood flow (rCBF), the mean transit time (MTT) and the cerebral blood volume (rCBV) in consideration of the arterial input function (AIF) can be calculated and visualized using color tables. Additionally, the calculation of ''time-to-peak'' maps (TTP) and of maps of the percentage change in signal intensity (PC) is possible. The analysis of n = 10 normal persons shows perfusion values that agree with those found in the literature. Discussion: With the computer program developed here color-coded perfusion parameter maps can be calculated easily. Because of the high computing speed it is possible to get information about tissue perfusion on the basis of the large MR data sets even in acute investigations. (orig.) [German] Ziel: Schnelle und bedienerfreundliche Auswertung von perfusions- und diffusions-gewichteten MRT-Daten mittels interaktiver Auswertesoftware. Methoden: Eine Windows {sup trademark} -basierte Software zur Auswertung von Perfusions- (PWI) und Diffusions-MRT (DWI) wurde entwickelt. Das Computerprogramm wurde in der Programmiersprache C++ unter Verwendung optimierter Algorithmen entwickelt, so dass eine hohe Rechengeschwindigkeit auf Win95/98/NT-Systemen erreicht wird. Die etablierten SVD-Algorithmen von Oestergaard zur quantitativen Perfusions-Auswertung wurden implementiert. Ergebnisse: Perfusions-Parameterbilder des zerebralen Blutflusses (rCBF), der mittleren

  11. 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

  12. 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

  13. INFLUENCE OF LOCAL INFILITRATION ANESTHESIA OF SCALP-POINT ON ACUPUNCTURE INDUCED CHANGES OF CEREBRAL BLOOD PERFUSION DETECTED BY SPECT

    Institute of Scientific and Technical Information of China (English)

    郭长春; 王凡; 贾少微

    2003-01-01

    Objective: To observe the influence of local infiltration anesthesia at the scalp-point on acupuncture stimulation induced changes of cerebral blood perfusion in the brain. Methods: Experiments were conducted in 10 healthy volunteer subjects (8 males and 2 females) who were ordered to take a lying position on a specific bed with their heads keeping in a fixed position. Scalp-point used was Motor Area (MS 6). The first syringe needle (gauge-5) was inserted into the scalp from the upper 1/5 of MS-6 and the second syringe needle inserted into the scalp from the middle 2/5 of MS-6 and advanced downward, with the two needles connected to a HAN's Therapeutic Apparatus. Images of the brain were then taken before and after electroacupuncture (EA) stimulation, and after local injection of 1% lidocaine [mixed with epinephrine (1∶200,000, 3 mL)] plus EA by using Siemens ECAM/ICON Single Photo Emission Computed Tomography (SPECT). Intravenous injection of Ethyl cysteinate dimmer 555 MBq was performed before displaying cerebral images. Data of blood functional changing rat (BFCR%) were analyzed quantitatively using a mathematic model. Results: Before EA stimulation, the blood perfusion and function of cerebral cortex, thalamus, basal ganglion and cerebellum on both sides of the brain were basically symmetry. Following EA of MS-6, BFCR% of the contralateral thalamus, parietal lobe and the frontal lobe increased significantly. Following local infiltration anesthesia, BFCR% of the contralatral thalamus declined markedly (P<0.05). The results of quantitative analysis were in agreement with those of visual observation. Conclusion: Local infiltration anesthesia of the scalp-point can significantly weaken or block EA stimulation induced changes of BFCR%.

  14. 大脑中动脉狭窄程度与脑灌注的相关性研究%Correlation between stenosis of middle cerebral artery and cerebral perfusion

    Institute of Scientific and Technical Information of China (English)

    史文倩; 石进; 杨帆; 时惠平

    2015-01-01

    Objective To investigate the correlation between stenosis of middle cerebral artery (MCA) and cerebral perfusion in patients with unilateral MCA stenosis.Methods Computed tomography perfusion (CTP) was performed in 34 patients with unilateral MCA stenosis,admitted to our hospital trom April 2012 to March 2013.The CTP parameters of mean transit time,cerebral blood flow,cerebral blood volume and time to peak were measured in regions supplied by anterior cerebral artery,MCA and posterior cerebral artery.All patients were divided into severe stenosis group and moderate stenosis group; the correlation between MCA stenosis and cerebral perfusion was analyzed.Results A decreased perfusion was detected in 25 patients (73.5%),and it was more likely found in the severe stenosis group (18/20,90%) than that in the moderate stenosis group (7/14,50%,P=0.017).The degree ofMCA stenosis was positively correlated with the changes of cerebral perfusion (r=0.381,P=0.026).The ratio of patients with transient ischemic attack (TIA) between the normal cerebral perfusion group and decreased cerebral perfusion group had statistical difference (11.11% vs.72.00%,P=0.004).Conclusion Cerebral perfusion is significantly correlated with the severity of MCA stenosis in unilateral MCA stenosis patients; the proportion of TIA in the low cerebral perfusion patients is higher than that in the normal cerebral perfusion ones.%目的 探讨单侧大脑中动脉(MCA)狭窄患者MCA狭窄程度与脑灌注的相关性.方法 对自2012年4月至2013年3月在北京空军总医院神经内科住院的34例单侧MCA狭窄患者行CT灌注成像(CTP)检查:在双侧半球大脑前动脉、MCA及大脑后动脉供血区选择对称的感兴趣区,测量CTP参数如脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)及达峰时间(TTP)等.并将患者按MCA狭窄程度分组(重度、中度),对狭窄程度与MCA供血区的脑灌注进行等级相关性分析. 结果 34例患者中有25

  15. 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;

    2014-01-01

    Acetylcholine may contribute to the increase in regional cerebral blood flow (rCBF) during cerebral activation since glycopyrrolate, a potent inhibitor of acetylcholine, abolishes the exercise-induced increase in middle cerebral artery mean flow velocity. We tested the hypothesis that cholinergic...... 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...

  16. SPECT measurement of cerebral hemodynamics in transient ischemic attack patients; Evaluation of pathogenesis and detection of misery perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Hiroshi; Takeshita, Gen; Takeuchi, Akira; Ejiri, Kazutaka; Maeda, Hisato; Katada, Kazuhiro; Koga, Sukehiko; Ishiyama, Norio; Kanno, Tetsuo (Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan))

    1989-12-01

    To evaluate the cerebral hemodynamics and the pathogenesis by regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV), 42 transient ischemic attack (TIA) patients and 9 normal volunteers were studied using SPECT. We classified these patients into Group A (n=23: no occlusion or stenosis of the internal carotid or middle cerebral artery; non large vessel disease) and Group B (n=19: chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery; large vessel disease). We obtained rCBF with {sup 133}Xe inhalation and rCBV with {sup 99m}Tc-red blood cells. Of 9 normal volunteers aged 43-70 yr (mean age 59.8{plus minus} 8.3 yr), the mean rCBF was 45.8{plus minus} 5.1 (ml/100 g brain/min), the mean rCBV was 4.0{plus minus} 0.4 (ml/100 g brain). The examination was done by comparing the values of the affected hemispheres of Group A and Group B patients with the mean rCBF and the mean rCBV of normal volunteers. Eleven out of Group A patients and 15 out of Group B patients showed decreased rCBF. But of those patients, no patients of Group A showed increased rCBV and 6 out of 19 Group B patients showed increased rCBV. Thromboembolic mechanism which is of Group A patients and Group B patients without increased rCBV, and hemodynamic mechanism which is of Group B patients with increased rCBV were considered as the main cause of TIA. Decreased rCBF and increased rCBV in Group B patients can be assumed as the misery perfusion as reported in PET studies. We conclude that SPECT measurement of not only rCBF but also rCBV on TIA patients is very significant to evaluate the pathogenesis and to detect the misery perfusion. (author).

  17. 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)

  18. 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

    )), glucose and lactate across the brain. The molar ratio between the cerebral uptake of O(2) versus carbohydrate (O(2)-carbohydrate index; O(2) / [glucose + 0.5 lactate]; OCI), the cerebral metabolic rate of O(2) (CMRO(2)) and changes in mitochondrial O(2) tension (P(mito)O(2)) were calculated. W...

  19. Increase in skin perfusion pressure after maggot debridement therapy for critical limb ischaemia.

    Science.gov (United States)

    Maeda, T M; Kimura, C K; Takahashi, K T; Ichimura, K I

    2014-12-01

    Skin perfusion pressure (SPP) is the perfusion pressure at the skin level, and it can serve as an index of peripheral circulation in the skin and subcutaneous tissue. We report a 78-year-old man with critical limb ischaemia who, despite having undergone several catheter interventions, still had severe ulcers with exposed bone on his right foot. We performed transmetatarsal amputation. The tissue around the surgical site became necrotic several days later, and did not respond to conservative therapy. Therefore, we opted for maggot debridement therapy (MDT), given that maggots favour necrotic tissue. After the therapy, SPP around the ulcer increased from 12 to 54 mmHg on the dorsal aspect, and from 17 to 44 mmHg on the plantar aspect. Wound healing was successfully activated by MDT, leading to complete healing within 2.5 months after MDT. We believe that MDT probably contributed to increase the blood supply to the ischaemic wound.

  20. Accuracy of computed tomography perfusion in detecting delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage: A meta-analysis

    Directory of Open Access Journals (Sweden)

    Haogeng Sun

    2013-01-01

    Full Text Available Background and Purpose: In recent years, significant literature shows that computed tomography perfusion (CTP can provide sufficient information on cerebral hemodynamics and effectively indicate delayed cerebral ischemia (DCI before the development of infarction. We aimed at performing a meta-analysis to provide a more full and accurate evaluation of CTP and CTP parameters in detecting DCI in patients with aneurysmal subarachnoid hemorrhage. Materials and Methods: We searched the PubMed, MedLine, Embase and Cochrane databases for analysis published from February 2005 to February 2013. We extracted CTP parameters, including cerebral blood volume (CBV, cerebral blood flow (CBF, mean transit time (MTT, time to peak (TTP, interhemispheric ratios for CBV and CBF and interhemispheric differences for MTT and TTP. Pooled estimates of sensitivity, specificity, positive likelihood ratio (PLR, negative likelihood ratio (NLR, diagnostic odds ratio (DOR and the summary receiver-operating characteristic curve were determined. Results: Four research studies are met the inclusion criteria for the analysis. The pooled sensitivity, specificity, PLR, NLR and DOR of CTP for detecting the DCI were 82%, 82%, 4.56, 0.22 and 20.96, respectively. Through the evaluation of absolute CTP parameters, CBF and MTT showed diagnostic value for DCI, but CBF and TTP did not. Moreover, CBF ratio, MTT difference and TTP difference showed more diagnostic value than CBV ratio in DCI detection by the assessment of relative CTP parameters. Conclusions: As a non-invasive and short time consuming screening method, CTP own a high diagnostic value for the detection of DCI after aneurysm rupture.

  1. 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...... together with administration of acetazolamide. From a combination of anatomic images with different signal weighting, regions of interest were generated corresponding to gray and white matter and WMH. Localized measurements of CBF and cerebral blood volume (CBV) and mean transit time were obtained directly...

  2. 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

    cerebral artery (MCA) was measured together with ventilatory parameters and heart rate before, during, and after immersion. RESULTS: Within seconds after immersion in ice water, heart rate increased from 74 +/- 16 to 107 +/- 18 bpm (mean +/- SD; p

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

    Institute of Scientific and Technical Information of China (English)

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

    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 metabolic profiling in rabbits with ASCP

  4. Microvascular hemodynamics in human hypothermic circulatory arrest and selective antegrade cerebral perfusion

    NARCIS (Netherlands)

    P.W.G. Elbers; A. Ozdemir; R.H. Heijmen; J. Heeren; M. van Iterson; E.P.A. van Dongen; C. Ince

    2010-01-01

    Objective: The behavior of the human microcirculation in the setting of cardiac arrest is largely unknown. Animal experiments have consistently revealed that global hemodynamics do not necessarily reflect microvascular perfusion. In addition, the time it takes for capillary blood flow to stop after

  5. 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

  6. 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)

    Ying Han

    2006-01-01

    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.

  7. Iterative image reconstruction for cerebral perfusion CT using a pre-contrast scan induced edge-preserving prior

    Science.gov (United States)

    Ma, Jianhua; Zhang, Hua; Gao, Yang; Huang, Jing; Liang, Zhengrong; Feng, Qianjing; Chen, Wufan

    2012-11-01

    Cerebral perfusion x-ray computed tomography (PCT) imaging, which detects and characterizes the ischemic penumbra, and assesses blood-brain barrier permeability with acute stroke or chronic cerebrovascular diseases, has been developed extensively over the past decades. However, due to its sequential scan protocol, the associated radiation dose has raised significant concerns to patients. Therefore, in this study we developed an iterative image reconstruction algorithm based on the maximum a posterior (MAP) principle to yield a clinically acceptable cerebral PCT image with lower milliampere-seconds (mA s). To preserve the edges of the reconstructed image, an edge-preserving prior was designed using a normal-dose pre-contrast unenhanced scan. For simplicity, the present algorithm was termed as ‘MAP-ndiNLM’. Evaluations with the digital phantom and the simulated low-dose clinical brain PCT datasets clearly demonstrate that the MAP-ndiNLM method can achieve more significant gains than the existing FBP and MAP-Huber algorithms with better image noise reduction, low-contrast object detection and resolution preservation. More importantly, the MAP-ndiNLM method can yield more accurate kinetic enhanced details and diagnostic hemodynamic parameter maps than the MAP-Huber method.

  8. 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...

  9. 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.

  10. Blood-brain barrier permeability is positively correlated with cerebral microvascular perfusion in the early fluid percussion-injured brain of the rat.

    Science.gov (United States)

    Lin, Yong; Pan, Yaohua; Wang, Mingliang; Huang, Xianjian; Yin, Yuhua; Wang, Yu; Jia, Feng; Xiong, Wenhao; Zhang, Nu; Jiang, Ji-yao

    2012-11-01

    The blood-brain barrier (BBB) opening following traumatic brain injury (TBI) provides a chance for therapeutic agents to cross the barrier, yet the reduction of the cerebral microvascular perfusion after TBI may limit the intervention. Meanwhile, optimizing the cerebral capillary perfusion by the strategies such as fluid administration may cause brain edema due to the BBB opening post trauma. To guide the TBI therapy, we characterized the relationship between the changes in the cerebral capillary perfusion and BBB permeability after TBI. First, we observed the changes of the cerebral capillary perfusion by the intracardiac perfusion of Evans Blue and the BBB disruption with magnetic resonance imaging (MRI) in the rat subjected to lateral fluid percussion (FP) brain injury. The correlation between two variables was next evaluated with the correlation analysis. Since related to BBB breakdown, matrix metalloproteinase-9 (MMP-9) activity was finally detected by gelatin zymography. We found that the ratios of the perfused microvessel numbers in the lesioned cortices were significantly reduced at 0 and 1 h post trauma compared with that in the normal cortex, which then dramatically recovered at 4 and 24 h after injury, and that the BBB permeability was greatly augmented in the ipsilateral parts at 4, 12, and 24 h, and in the contralateral area at 24 h after injury compared with that in the uninjured brain. The correlation analysis showed that the BBB permeability increase was related to the restoration of the cerebral capillary perfusion over a 24-h period post trauma. Moreover, the gelatin zymography analysis indicated that the MMP-9 activity in the injured brain increased at 4 h and significantly elevated at 12 and 24 h as compared to that at 0 or 1 h after TBI. Our findings demonstrate that the 4 h post trauma is a critical turning point during the development of TBI, and, importantly, the correlation analysis may guide us how to treat TBI.

  11. 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.

  12. 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.

  13. Changes of cerebral hemodynamics in CT perfusion imaging of rabbit models with cerebral microembolism%兔脑微栓塞模型脑血流动力学的CT灌注动态变化

    Institute of Scientific and Technical Information of China (English)

    张放; 姚振威; 冯晓源; 孙华平

    2012-01-01

    目的 探讨兔脑微栓塞模型CT灌注成像(CT perfusion imaging,CTPI)脑血流动力学的动态变化规律.方法 30只新西兰兔,随机分成两组,A组:假手术对照组5只,B组:微栓塞组25只.经颈外动脉向颈内动脉注入直径约0.5 mm的SiO2颗粒10枚,分别于栓塞后30 min、3h、6h、12 h及24 h行CTPI,24 h处死动物取脑组织行HE染色.根据HE染色结果将模型分为缺血组和梗死组,分别观察其脑血流量(cerebral blood flow,CBF)、脑血容积(cerebral blood volume,CBV)和平均通过时间(mean transit time,MTT)的动态变化规律.结果 A组CTPI及HE染色均未见明显异常.B组3只因实验意外死亡,1只因下肢静脉穿刺失败导致CTPI失败,21只行CTPI,其中18只灌注异常,3只未见明显异常.18只灌注异常的兔中,HE染色10只脑梗死,7只脑缺血,1只未见明显异常.30 min时7只缺血兔脑不同程度低灌注,表现为CBF降低,MTT延长,CBV无显著变化,3~6h低灌注进一步加重,CBV值略降低,12h低灌注不同程度恢复,24 h进一步恢复.30 min时10只梗死兔脑明显低灌注,表现为CBF及CBV显著降低,MTT显著延长,3只兔低灌注分别在3h、6h及12 h不同程度恢复,然后下一时间又迅速降低并随着时间延长进一步加剧,其余7只兔低灌注程度随时间延长逐渐加剧或在一定水平上波动.结论 脑缺血3~6h低灌注最明显,12~ 24 h低灌注不同程度恢复,而脑梗死随时间延长低灌注程度不断加重或一过性恢复后再次加重.脑缺血的特征是CBF和CBV的不匹配,缺血组织CBF显著降低,CBV无显著变化,而脑梗死则表现为这两个参数的一致性下降.%Objective To study the changes of cerebral hemodynamics revealed by CT perfusion imaging ( CTPI) in rabbit models of cerebral microembolism. Methods Thirty normal New Zealand rabbits were randomly divided into two groups; Group A (n =5) underwent sham operation, group B (n =25) underwent an operation of microembolism

  14. Detection of misery perfusion in the cerebral hemisphere with chronic unilateral major cerebral artery steno-occlusive disease using crossed cerebellar hypoperfusion: comparison of brain SPECT and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Yoshiyasu; Ogasawara, Kuniaki; Saito, Hideo; Takahashi, Yoshihiro; Ogasawara, Yasushi; Kobayashi, Masakazu; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Terasaki, Kazunori [Iwate Medical University, Cyclotron Research Center, Morioka (Japan); Yoshida, Kenji; Beppu, Takaaki; Kubo, Yoshitaka; Fujiwara, Shunrou [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Tsushima, Eiki [Hirosaki University, Graduate School of Health Sciences, Hirosaki (Japan)

    2013-10-15

    In patients with unilateral internal carotid or middle cerebral artery (ICA or MCA) occlusive disease, the degree of crossed cerebellar hypoperfusion that is evident within a few months after the onset of stroke may reflect cerebral metabolic rate of oxygen in the affected cerebral hemisphere relative to that in the contralateral cerebral hemisphere. The aim of the present study was to determine whether the ratio of blood flow asymmetry in the cerebellar hemisphere to blood flow asymmetry in the cerebral hemisphere on positron emission tomography (PET) and single photon emission computed tomography (SPECT) correlates with oxygen extraction fraction (OEF) asymmetry in the cerebral hemisphere on PET in patients with chronic unilateral ICA or MCA occlusive disease and whether this blood flow ratio on SPECT detects misery perfusion in the affected cerebral hemisphere in such patients. Brain blood flow and OEF were assessed using {sup 15}O-PET and N-isopropyl-p-[{sup 123}I]iodoamphetamine ({sup 123}I-IMP) SPECT, respectively. All images were anatomically standardized using SPM2. A region of interest (ROI) was automatically placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres using a three-dimensional stereotaxic ROI template, and affected-to-contralateral asymmetry in the MCA territory or contralateral-to-affected asymmetry in the cerebellar hemisphere was calculated. Sixty-three patients with reduced blood flow in the affected cerebral hemisphere on {sup 123}I-IMP SPECT were enrolled in this study. A significant correlation was observed between MCA ROI asymmetry of PET OEF and the ratio of cerebellar hemisphere asymmetry of blood flow to MCA ROI asymmetry of blood flow on PET (r = 0.381, p = 0.0019) or SPECT (r = 0.459, p = 0.0001). The correlation coefficient was higher when reanalyzed in a subgroup of 43 patients undergoing a PET study within 3 months after the last ischemic event (r = 0.541, p = 0.0001 for PET; r = 0.609, p < 0

  15. Optical coherence tomography microangiography for monitoring the response of vascular perfusion to external pressure on human skin tissue

    Science.gov (United States)

    Choi, Woo June; Wang, Hequn; Wang, Ruikang K.

    2014-05-01

    Characterization of the relationship between external pressure and blood flow is important in the examination of pressure-induced disturbance in tissue microcirculation. Optical coherence tomography (OCT)-based microangiography is a promising imaging technique, capable of providing the noninvasive extraction of functional vessels within the skin tissue with capillary-scale resolution. Here, we present a feasibility study of OCT microangiography (OMAG) to evaluate changes in blood perfusion in response to externally applied pressure on human skin tissue in vivo. External force is loaded normal to the tissue surface at the nailfold region of a healthy human volunteer. An incremental force is applied step by step and then followed by an immediate release. Skin perfusion events including baseline are continuously imaged by OMAG, allowing for visualization and quantification of the capillary perfusion in the nailfold tissue. The tissue strain maps are simultaneously evaluated through the available OCT structural images to assess the relationship of the microcirculation response to the applied pressure. The results indicate that the perfusion progressively decreases with the constant increase of pressure. Reactive hyperemia occurs right after the removal of the pressure. The perfusion returns to the baseline level after a few minutes. These findings suggest that OMAG may have great potential for quantitatively assessing tissue microcirculation in the locally pressed tissue in vivo.

  16. 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

    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...... no significant effect. Using a myograph technique, isolated ring segments of the MCA with intact endothelium were mounted on two metal wires. Neither agonist caused relaxation of resting vessels, however, they both responded by weak contractile responses (26+/-3% of submaximal contractile capacity relative to 60...

  17. 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...

  18. 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

    . INTERVENTIONS:: Systemic hemodynamics, middle cerebral artery mean flow velocity, and dynamic cerebral autoregulation evaluated by transfer function analysis in the very low (0.15 Hz) frequency ranges were monitored in these volunteers before and after an endotoxin bolus (2 ng/kg; Escherichia coli...... flow velocity (37 ± 9 cm·sec vs. 47 ± 10 cm·sec; p velocity variability (1.0 ± 1.0 [cm·sec] Hz vs. 2.8 ± 1.5 [cm·sec] Hz; p ...·sec.mm Hg vs. 0.74 ± 0.17 cm·sec.mm Hg; p velocity phase difference (p

  19. 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...

  20. 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

    together with administration of acetazolamide. From a combination of anatomic images with different signal weighting, regions of interest were generated corresponding to gray and white matter and WMH. Localized measurements of CBF and cerebral blood volume (CBV) and mean transit time were obtained directly...... within WMH and NAWM. RESULTS: When comparing WMH to NAWM, measurements showed significantly lower CBF (P=0.004) and longer mean transit time (P

  1. [Alterations in cerebral perfusion in patients with systemic sclerosis and cognitive impairment].

    Science.gov (United States)

    Moreno-Gutiérrez, Juan; Coria-Moctezuma, Luis Alonso; del Pilar Cruz-Domínguez, María; Vera-Lastra, Olga Lidia

    2015-01-01

    Introducción: la esclerosis sistémica (ES) es una enfermedad autoinmune, sistémica, caracterizada por fibrosis, alteraciones inmunológicas y vasculares. La hipoperfusión cerebral puede ser causada por isquemia. Los trastornos cognitivos son causa importante de morbilidad. El objetivo de este estudio fue determinar la frecuencia de alteraciones en la perfusión cerebral (PC) en pacientes con ES y deterioro cognitivo (DC). Métodos: se estudiaron 88 pacientes con ES. A todos se les aplicó el Test de Montreal (TM) para evaluar el DC. A 15 pacientes con DC que cumplieron con los criterios (sin hipertensión arterial sistémica, diabetes mellitus, evento vascular cerebral, vasculitis, hipotiroidismo, depresión, sin ingesta de fármacos que interfieran con la evaluación cognitiva), se les midió la PC mediante Gamagrama Cerebral Perfusorio (GCP).Resultados: de los 88 pacientes con ES, 58 tuvieron DC con el TM. La PC se encontró disminuida en 12/15. La disminución de la PC se observó en los siguientes lóbulos (frontal en 9/15; temporal en 7/15, y parietal en 3/15. La concordancia entre el TM y GC fue 60 % para el lóbulo frontal, 46 % para el lóbulo temporal y 13 % parietal.Conclusiones: el DC es frecuente en la ES, la disminución de la PC fue más común en el lóbulo frontal, predominado en los pacientes de mayor edad y tiempo de evolución de la ES.

  2. 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....

  3. 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...

  4. 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...

  5. 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....

  6. 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

  7. 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

  8. 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.)

  9. Perfusão da artéria pulmonar não melhora os índices de fator natriurético cerebral (BNP em estudo experimental em suínos Pulmonary artery perfusion does not improve brain natriuretic peptide (BNP levels in suine experimental research

    Directory of Open Access Journals (Sweden)

    Edmo Atique Gabriel

    2010-12-01

    Full Text Available OBJETIVO: Avaliar se perfusão controlada do tronco pulmonar durante circulação extracorpórea (CEC modifica os níveis de BNP expressos pelo miocárdio ventricular. MÉTODOS: Estudo experimental com 32 porcos, divididos em dois grupos de acordo com estratégia de CEC - grupo I (cardioplegia e grupo II (coração batendo. Ambos os grupos foram alocados em três subgrupos, de acordo com a estratégia de perfusão pulmonar - subgrupo A (controle: sem perfusão pulmonar, subgrupo B (perfusão pulmonar com sangue arterial e subgrupo C (perfusão com sangue venoso. Nos subgrupos B e C, pulmões foram perfundidos por 30 minutos, utilizando pressão arterial média pulmonar (PAPM préoperatória como pressão de perfusão, a qual foi controlada com manômetro. PAPM e resistência vascular pulmonar (RVP foram medidas após saída de CEC com cateter de Swan-Ganz. No período pré-operatório e após 30 minutos de perfusão pulmonar, fragmentos de miocárdio ventricular direito foram coletados para avaliar expressão de peptídeo natriurético cerebral (BNP e padrão histológico tecidual. Técnicas de imunohistoquímica e hematoxilina-eosina foram utilizadas para determinar, respectivamente, expressão de BNP e lesões inflamatórias miocárdicas. RESULTADOS: Nos animais submetidos à perfusão controlada do tronco pulmonar, houve redução pós-operatória da PAPM (P=0,03 e da RVP (P=0,005. Não houve diferenças entre os subgrupos do grupo I (P=0,228 e subgrupos do grupo II (P=0,325 quanto à expressão pós-operatória de BNP. Não houve diferenças entre subgrupos com e sem perfusão pulmonar quanto à intensidade das lesões inflamatórias miocárdicas identificadas no pós-operatório (P>0,05. CONCLUSÃO: Perfusão controlada do tronco pulmonar por 30 minutos não foi suficiente para promover alterações substanciais na expressão de BNP e no padrão histológico miocárdico do ventrículo direito.OBJECTIVE: Assess if the main pulmonary artery

  10. 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

  11. 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.)

  12. Clinical Application of CT Cerebral Perfusion and Angiography in Acute Cerebral Infarction%CT脑灌注与血管造影在急性脑梗死中的临床应用

    Institute of Scientific and Technical Information of China (English)

    娄雪磊

    2015-01-01

    目的:探讨CT脑灌注与血管造影在急性脑梗死中的临床应用效果。方法选择医院2014年12月~2015年6月诊治的急性脑梗死患者中抽取75例作研究对象,对其分别进行CT脑灌注和血管造影检查,对比两种检查方法的诊断情况。结果 CT灌注图内,对应患者的临床症状的灌注异常处有63例,其阳性率是84.0%,高于CT检测的19例,其阳性率是25.3%(P<0.05);同时,经CT脑灌注和血管造影检测发现,责任血管者采取CT脑灌注检测阳性者48例,其阳性率是64.0%,无责任血管者13例,其阳性率是17.3%(P<0.05)。结论 CT脑灌注与血管造影在急性脑梗死中的临床应用效果确切,有助于为急性脑梗死预防、治疗措施的制定提供参考依据。%Objective To study the clinical application effect of CT cerebral perfusion with angiography in acute cerebral infarction.Methods In a hospital in December 2014 to June 2015 in the diagnosis and treatment of acute cerebral infarction patients from 75 cases as the research object,the CT cerebral perfusion and angiography respectively,compared to two kinds of inspection methods of diagnosis.ResultsCT perfusion in the figure, the corresponding clinical symptoms in patients with perfusion abnormalities in 63 cases,the positive rate was 84.0%,significantly higher than that of CT detection of 19 cases,the positive rate was 25.3%(P<0.05,at the same time,CT cerebral perfusion and angiographic examination found that responsibility vessels take CT cerebral perfusion was 48 cases,the positive rate was 64.0%,significantly less responsibility 13 cases of blood vessels,the positive rate was 17.3%(P<0.05). ConclusionCT cerebral perfusion with angiography in acute cerebral infarction clinical application effect of precise,help for acute cerebral infarction,to provide the reference basis for the establishment of prevention and treatment measures.

  13. 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

    The aim of the present study was to calculate critical closing pressure (CCP) of the cerebral vasculature at rest and during exercise to estimate cerebral vascular tone. Five men and two women were seated upright for 15 min and then performed 15 min of right-legged knee extension exercise at 40, 60...... and 75% of their maximal workload (WL(max)). Middle cerebral artery blood velocity (MCA V) and blood pressure in the radial artery were recorded. The CCP was calculated by linear extrapolation from 1 min recordings of pairs of systolic and diastolic pressure and MCA V waveforms from both the right...

  14. 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, frontal...... blood flow was reported to be lower compared with other brain regions, indicating greater arteriolar tone and perhaps preserved regional cerebral autoregulation. In patients with severe FHF (6 women, 1 man; median age, 46 years; range, 18 to 55 years), we tested the hypothesis that perfusion...... in the anterior cerebral artery would be less affected by an increase in mean arterial pressure compared with the brain area supplied by the middle cerebral artery. Relative changes in cerebral perfusion were determined by transcranial Doppler-measured mean flow velocity (V(mean)), and resistance was determined...

  15. 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 mm......Hg, 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...... 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....

  16. 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 mm......Hg 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 less than 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...

  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

    2016-04-27

    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 [(11)C]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.

  18. Technetium-99m d,l-HM-PAO: a new radiopharmaceutical for SPECT imaging of regional cerebral blood perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Neirinckx, R.D.; Canning, L.R.; Piper, I.M.; Nowotnik, D.P.; Pickett, R.D.; Holmes, R.A.; Volkert, W.A.; Forster, A.M.; Weisner, P.S.; Marriott, J.A.

    1987-02-01

    Following investigation of a large number of new ligands based upon propylene amine oxime (PnAO) the d,l-diastereoisomer of hexamethyl propyleneamine oxime (HM-PAO) was selected as the preferred ligand for 99mTc as a tracer for cerebral perfusion imaging. The neutral, lipophilic 99mTc complex of d,l-HM-PAO was formed in high yield by stannous reduction of 99Mo/99mTc generator eluate using a kit formulation of the ligand. Two minutes following i.v. administration of this complex in rats, 2.25% of the injected dose appears in the brain. Little washout of the tracer is observed up to 24 hr postinjection. By qualitative autoradiographic comparison with iodoantipyrine this new radiopharmaceutical displays blood flow dependent brain uptake with little redistribution of the tracer over time. The lipophilic 99mTc complex converts slowly in vitro to a secondary complex. This conversion process may account for the ability of (99mTc)d,l-HM-PAO to be retained within the brain without redistribution.

  19. The relation of regional cerebral perfusion and atrophy in mild cognitive impairment (MCI) and early Alzheimer's dementia.

    Science.gov (United States)

    Luckhaus, Christian; Cohnen, Mathias; Flüss, Michael Oliver; Jänner, Michaela; Grass-Kapanke, Brigitte; Teipel, Stefan J; Grothe, Michel; Hampel, Harald; Peters, Oliver; Kornhuber, Johannes; Maier, Wolfgang; Supprian, Tillmann; Gaebel, Wolfgang; Mödder, Ulrich; Wittsack, Hans-Jörg

    2010-07-30

    The spatial and temporal relations between regional cerebral blood flow (rCBF) and brain volume (rVOL) changes in incipient and early Alzheimer's dementia (AD) are not fully understood. The participants comprised 30 subjects with mild cognitive impairment (MCI) and 15 with mild AD who were examined using structural and perfusion-weighted magnetic resonance imaging (MRI) at 1.5 Tesla. Hippocampus and amygdala volumes were measured by manual volumetry. A region-of-interest co-localisation method was used to calculate rCBF values. DNA samples were genotyped for apolipoprotein E (APO E). In comparisons of AD with MCI, rCBF was reduced in the posterior cingulum only, while profound rVOL reductions occurred in both right and left amygdala and in the right hippocampus, and as a trend, in the left hippocampus. Brain volumes of the hippocampus and the amygdala were uncorrelated with the respective rCBF variables in both MCI and AD. Hippocampal but not amygdalar volumes were associated with presence of one or two APOE epsilon4 alleles in MCI and mild AD, while there was no association of APOE epsilon4 allele with rCBF. These data support earlier indications that rCBF and rVOL changes are at least partly dissociated in the early pathogenesis of AD and heterogeneously associated with the APOE risk allele. The data also support the concept of functional compensatory brain activation and the diaschisis hypothesis as relevant in incipient and early AD.

  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.

  1. Expansion duroplasty improves intraspinal pressure, spinal cord perfusion pressure, and vascular pressure reactivity index in patients with traumatic spinal cord injury: injured spinal cord pressure evaluation study.

    Science.gov (United States)

    Phang, Isaac; Werndle, Melissa C; Saadoun, Samira; Varsos, Georgios; Czosnyka, Marek; Zoumprouli, Argyro; Papadopoulos, Marios C

    2015-06-15

    We recently showed that, after traumatic spinal cord injury (TSCI), laminectomy does not improve intraspinal pressure (ISP), spinal cord perfusion pressure (SCPP), or the vascular pressure reactivity index (sPRx) at the injury site sufficiently because of dural compression. This is an open label, prospective trial comparing combined bony and dural decompression versus laminectomy. Twenty-one patients with acute severe TSCI had re-alignment of the fracture and surgical fixation; 11 had laminectomy alone (laminectomy group) and 10 had laminectomy and duroplasty (laminectomy+duroplasty group). Primary outcomes were magnetic resonance imaging evidence of spinal cord decompression (increase in intradural space, cerebrospinal fluid around the injured cord) and spinal cord physiology (ISP, SCPP, sPRx). The laminectomy and laminectomy+duroplasty groups were well matched. Compared with the laminectomy group, the laminectomy+duroplasty group had greater increase in intradural space at the injury site and more effective decompression of the injured cord. In the laminectomy+duroplasty group, ISP was lower, SCPP higher, and sPRx lower, (i.e., improved vascular pressure reactivity), compared with the laminectomy group. Laminectomy+duroplasty caused cerebrospinal fluid leak that settled with lumbar drain in one patient and pseudomeningocele that resolved completely in five patients. We conclude that, after TSCI, laminectomy+duroplasty improves spinal cord radiological and physiological parameters more effectively than laminectomy alone.

  2. The Effect of Milrinone on Splanchnic and Cerebral Perfusion in Infants With Congenital Heart Disease Prior to Surgery: An Observational Study.

    Science.gov (United States)

    Bianchi, Maria Otilia; Cheung, Po-Yin; Phillipos, Ernest; Aranha-Netto, Abimael; Joynt, Chloe

    2015-08-01

    Despite the advancement in the postoperative care of neonates with congenital heart disease (CHD), there is little information on preoperative management of systemic and regional hemodynamics, which may be related to outcomes. We aimed to determine the preoperative effect of milrinone, a phosphodiesterase III inhibitor, on cardiac output and splanchnic and cerebral perfusion in neonates with CHD. Neonates with CHD requiring cardiac surgery were enrolled in a prospective, single-blinded study once a clinical decision of starting milrinone (0.75 μg/kg per minute intravenously) using institutional criteria was made. Demographic and clinical variables and outcomes were recorded. Combined cardiac output and measures of splanchnic (superior mesenteric and celiac arteries) and cerebral (anterior and middle cerebral arteries) perfusion were determined by Doppler studies at 0, 6, 24, and 48 h after milrinone infusion. Investigators were unaware of intervention time points and patients in analyzing blood flow measurements. Seventeen term (39.2 ± 1.3 weeks) neonates were included with hypoplastic left-sided heart syndrome (78.5%) as the most common diagnosis. Combined cardiac output increased by 28% within 48 h (613 ± 154 vs. 479 ± 147 mL/kg per minute at baseline, P mean velocity increased at 6 h and throughout 48 h of milrinone infusion (P mean velocities at cerebral arteries increased with milrinone infusion (P < 0.05~0.08), and the corresponding changes at celiac artery were modest. There were no significant changes in splanchnic and cerebral resistive and pulsatility indices during milrinone infusion. Milrinone increases cardiac output with concurrent effects on splanchnic and cerebral blood flows during the short-term preoperative use in neonates with CHD.

  3. 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)

  4. 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....

  5. 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

  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. 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

  8. 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

  9. 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

  10. 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.)

  11. 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.)

  12. 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.)

  13. 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.

  14. 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.

  15. 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.)

  16. 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.)

  17. 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.

  18. [The peripheral perfusion pressure: a new non-invasive parameter for the circulatory monitoring of patients (author's transl)].

    Science.gov (United States)

    Huch, A; Lübbers, D W; Huch, R

    1975-01-01

    Heating of a skin area to a temperature of 42 degrees to 44 degrees C produces a certain physiological condition which induces maximal vasodilatation. Detailed experiments have shown that local peripheral vascular resistance of such an area remains constant for several hours. The flow in this area is proportional to the actual perfusion pressure. Relative flow was measured by means of a new type of electrode fixed to the skin like and ECG electrode, and compared with simultaneous intra-arterial blood pressure measruements. The changes in arterial blood pressure were also recorded by the skin electrode. This new parameter is defined as "peripheral perfusion pressure". It is appropiate for non-invasive continuous monitoring of the circulatory system of patients.

  19. 脑动脉瘤破裂手术前后的脑灌注成像探讨%The study of cerebral perfusion imaging for the ruptured cerebral aneurysms before and after the operation

    Institute of Scientific and Technical Information of China (English)

    林怡; 段玉霞; 李瑞; 陈伟建; 吴楠; 童秋云; 王殊

    2013-01-01

    目的:通过CT灌注成像观察颅内动脉瘤破裂出血手术前后的脑血流变化,为临床后续治疗提供相关信息.方法:回顾性分析颅内动脉瘤破裂手术前、后临床资料44例.所选患者术前行CT血管成像(CTA)和CT灌注成像(CTP)检查,并于术后1周行CTP复查.分别测量前后两次CTP的大脑前动脉区(ACA区)、大脑中动脉区(MCA区)、大脑后动脉区(PCA区)及基底节区灌注值.结果:44例入选患者中,34例伪彩图肉眼可见好转,患者的ACA区、MCA区、PCA区及基底节区脑血流量(CBF)与平均通过时间(MTT)变化差异有统计学意义(P< 0.05);8例肉眼可见局部灌注减低区的MTT值均延长、CBF值减低;2例灌注值未见明显异常.所有患者的脑血容量(CBV)值变化差异均无统计学意义.结论:颅内动脉瘤破裂手术前及手术后存在脑灌注调整,视个体和病情各异,脑灌注也将发生相应的变化.%Objective:To provide relevant information for clinical follow-up treatment through the observation on cerebral hemodynamic changes of ruptured intracranial aneurysm before and after operation in the CT perfusion imaging.Methods:The retrospective analysis of the pre-and post-operative clinical data in 44 patients with ruptured cerebral aneurysms was performed.These patients underwent CTA and CTP examination simultaneously before surgery,followed by CTP examination after operation.Then the perfusion values of anterior cerebral arterial territory (ACA area),middle cerebral arterial territory (MCA area),posterior cerebral arterial territory (PCA area) and basal ganglia area were respectively measured.Results:Among the 44 patients,the pseudo-color images of 34 patients showed visible improvement.In these patients,there was a significant change (P<0.05) between CBF and MTT in ACA,MCA,PCA and basal ganglia area.In the decreased perfusion area of 8 patients,which was visible to the naked eye,the MTT value was extended,and the CBF value was

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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)

  5. 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

  6. 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...

  7. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Benson, John; Payabvash, Seyedmehdi [Hennepin County and University of Minnesota Medical Centers, Department of Radiology, Minneapolis, MN (United States); Salazar, Pascal [Vital Images, A Division of Toshiba Medical, Minnetonka, MN (United States); Jagadeesan, Bharathi; Palmer, Christopher S.; Truwit, Charles L. [Hennepin County and University of Minnesota Medical Centers, Department of Radiology, Minneapolis, MN (United States); McKinney, Alexander M., E-mail: mckinrad@umn.edu [Hennepin County and University of Minnesota Medical Centers, Department of Radiology, Minneapolis, MN (United States)

    2015-04-15

    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.

  9. 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.

  10. 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

  11. 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

  12. Comparison of the cerebral SPECT and biological markers in the Alzheimer disease; Comparaison de la tomographie cerebrale par emission monophotonique de perfusion et des biomarqueurs dans la maladie d'Alzheimer

    Energy Technology Data Exchange (ETDEWEB)

    Ravasi, L.; Semah, F.; Steinling, M. [Unite imagerie fonctionnelle cerebrale, CHRU de Lille, (France); Bombois, S.; Pasquier, F. [centre memoire de ressources et de recherche, CHRU de Lille, (France); Schraen, S.; Buee, L. [Inserm U837, centre de biologie, CHRU de Lille, (France)

    2009-05-15

    This study aim was to compare the contribution of SPECT of cerebral perfusion and bio markers of the cerebrospinal liquid in the diagnosis of Alzheimer disease. Our preliminary conclusions show that the concordance of the SPECT and cerebrospinal liquid is good in the possible Alzheimer disease. the interest of the cerebral SPECT and bio markers of the cerebrospinal liquid, used alone or conjointly, for a more reliable diagnosis of Alzheimer disease must be evaluated of prospective way. (N.C.)

  13. Quantitative 3D pulmonary MR-perfusion in patients with pulmonary arterial hypertension: Correlation with invasive pressure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ley, Sebastian [Department of Pediatric Radiology, Children' s Hospital University Heidelberg, Im Neuenheimer Feld 153, 69120 Heidelberg (Germany) and Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)]. E-mail: ley@gmx.net; Mereles, Derliz [Internal Medicine III, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Risse, Frank [Medical Physics in Radiology (E020), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Gruenig, Ekkehard [Internal Medicine III, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Ley-Zaporozhan, Julia [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Tecer, Zueleyha [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Puderbach, Michael [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Fink, Christian [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Clinical Radiology, University Medical Center Grosshadern, Ludwigs-Maximilians-University, Munich (Germany); Kauczor, Hans-Ulrich [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

    2007-02-15

    Purpose: Pathological changes of the peripheral pulmonary arteries induce pulmonary arterial hypertension (PAH). Aim of this study was to quantitatively assess the effect of PAH on pulmonary perfusion by 3D-MR-perfusion techniques and to compare findings to healthy controls. Furthermore, quantitative perfusion data were correlated with invasive pressure measurements. Material and methods: Five volunteers and 20 PAH patients (WHO class II or III) were examined using a 1.5 T MR scanner. Measurement of pulmonary perfusion was done in an inspiratory breathhold (FLASH3D; 3.5 mm x 1.9 mm x 4 mm; TA per 3D dataset 1.5 s). Injection of contrast media (0.1 mmol Gd-DTPA/kg BW) and image acquisition were started simultaneously. Evaluation of 3D perfusion was done using singular value decomposition. Lung borders were outlined manually. Each lung volume was divided into three regions (anterior, middle, posterior), and the following parameters were assessed: Time-to-Peak (TTP), blood flow (PBF), blood volume (PBV), and mean transit time (MTT). In 10 patients invasive pulmonary artery pressure measurements were available and correlated to the perfusion measurements. Results: In both, controls and patients, an anterior-to-posterior gradient with higher PBF and PBV posterior was observed. In the posterior lung region, a significant difference (p < 0.05) was found for TTP (12 s versus 16 s) and MTT (4 s versus 6 s) between volunteers and patients. PBF and PBV were lower in patients than in volunteers (i.e. dorsal regions: 124 versus 180 ml/100 ml/min and 10 versus 12 ml/100 ml), but the difference failed to be significant. The ratio of PBF and PBV between the posterior and the middle or ventral regions showed no difference between both groups. A moderate linear correlation between mean pulmonary arterial pressure (mPAP) and PBV (r = 0.51) and MTT (r = 0.56) was found. Conclusion: The only measurable effect of PAH on pulmonary perfusion is a prolonging of the MTT. There is only a

  14. Gradual Rewarming with Gradual Increase in Pressure during Machine Perfusion after Cold Static Preservation Reduces Kidney Ischemia Reperfusion Injury.

    Directory of Open Access Journals (Sweden)

    Paria Mahboub

    Full Text Available In this study we evaluated whether gradual rewarming after the period of cold ischemia would improve organ quality in an Isolated Perfused Kidney Model. Left rat kidneys were statically cold stored in University of Wisconsin solution for 24 hours at 4°C. After cold storage kidneys were rewarmed in one of three ways: perfusion at body temperature (38°C, or rewarmed gradually from 10°C to 38°C with stabilization at 10°C for 30 min and rewarmed gradually from 10°C to 38°C with stabilization at 25°C for 30 min. In the gradual rewarming groups the pressure was increased stepwise to 40 mmHg at 10°C and 70 mmHg at 25°C to counteract for vasodilatation leading to low perfusate flows. Renal function parameters and injury biomarkers were measured in perfusate and urine samples. Increases in injury biomarkers such as aspartate transaminase and lactate dehydrogenase in the perfusate were lower in the gradual rewarming groups versus the control group. Sodium re-absorption was improved in the gradual rewarming groups and reached significance in the 25°C group after ninety minutes of perfusion. HSP-70, ICAM-1, VCAM-1 mRNA expressions were decreased in the 10°C and 25°C groups. Based on the data kidneys that underwent gradual rewarming suffered less renal parenchymal, tubular injury and showed better endothelial preservation. Renal function improved in the gradual rewarming groups versus the control group.

  15. Spatial frequency-based analysis of mean red blood cell speed in single microvessels: investigation of microvascular perfusion in rat cerebral cortex.

    Directory of Open Access Journals (Sweden)

    Joonas Autio

    Full Text Available BACKGROUND: Our previous study has shown that prenatal exposure to X-ray irradiation causes cerebral hypo-perfusion during the postnatal development of central nervous system (CNS. However, the source of the hypo-perfusion and its impact on the CNS development remains unclear. The present study developed an automatic analysis method to determine the mean red blood cell (RBC speed through single microvessels imaged with two-photon microscopy in the cerebral cortex of rats prenatally exposed to X-ray irradiation (1.5 Gy. METHODOLOGY/PRINCIPAL FINDINGS: We obtained a mean RBC speed (0.9±0.6 mm/sec that ranged from 0.2 to 4.4 mm/sec from 121 vessels in the radiation-exposed rats, which was about 40% lower than that of normal rats that were not exposed. These results were then compared with the conventional method for monitoring microvascular perfusion using the arteriovenous transit time (AVTT determined by tracking fluorescent markers. A significant increase in the AVTT was observed in the exposed rats (1.9±0.6 sec as compared to the age-matched non-exposed rats (1.2±0.3 sec. The results indicate that parenchyma capillary blood velocity in the exposed rats was approximately 37% lower than in non-exposed rats. CONCLUSIONS/SIGNIFICANCE: The algorithm presented is simple and robust relative to monitoring individual RBC speeds, which is superior in terms of noise tolerance and computation time. The demonstrative results show that the method developed in this study for determining the mean RBC speed in the spatial frequency domain was consistent with the conventional transit time method.

  16. Analysis of dynamic cerebral contrast-enhanced perfusion MRI time-series based on unsupervised clustering methods

    Science.gov (United States)

    Lange, Oliver; Meyer-Baese, Anke; Wismuller, Axel; Hurdal, Monica

    2005-03-01

    We employ unsupervised clustering techniques for the analysis of dynamic contrast-enhanced perfusion MRI time-series in patients with and without stroke. "Neural gas" network, fuzzy clustering based on deterministic annealing, self-organizing maps, and fuzzy c-means clustering enable self-organized data-driven segmentation w.r.t.fine-grained differences of signal amplitude and dynamics, thus identifying asymmetries and local abnormalities of brain perfusion. We conclude that clustering is a useful extension to conventional perfusion parameter maps.

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

    Science.gov (United States)

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

    2016-09-01

    Steady-state tilt has no effect on cerebrovascular reactivity to increases in the partial pressure of end-tidal carbon dioxide (PETCO2). However, the anterior and posterior cerebral circulations may respond differently to a variety of stimuli that alter central blood volume, including lower body negative pressure (LBNP). Little is known about the superimposed effects of head-up tilt (HUT; decreased central blood volume and intracranial pressure) and head-down tilt (HDT; increased central blood volume and intracranial pressure), and LBNP on cerebral blood flow (CBF) responses. We hypothesized that (a) cerebral blood velocity (CBV; an index of CBF) responses during LBNP would not change with HUT and HDT, and (b) CBV in the anterior cerebral circulation would decrease to a greater extent compared to posterior CBV during LBNP when controlling PETCO2 In 13 male participants, we measured CBV in the anterior (middle cerebral artery, MCAv) and posterior (posterior cerebral artery, PCAv) cerebral circulations using transcranial Doppler ultrasound during LBNP stress (-50 mmHg) in three body positions (45°HUT, supine, 45°HDT). PETCO2 was measured continuously and maintained at constant levels during LBNP through coached breathing. Our main findings were that (a) steady-state tilt had no effect on CBV responses during LBNP in both the MCA (P = 0.077) and PCA (P = 0.583), and (b) despite controlling for PETCO2, both the MCAv and PCAv decreased by the same magnitude during LBNP in HUT (P = 0.348), supine (P = 0.694), and HDT (P = 0.407). Here, we demonstrate that there are no differences in anterior and posterior circulations in response to LBNP in different body positions. PMID:27634108

  18. 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)

  19. 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)

  20. 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

  1. 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...

  2. 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.)

  3. Three-dimensional perfusion imaging in acute cerebral infarction%三维CT灌注成像在急性脑梗死中的应用

    Institute of Scientific and Technical Information of China (English)

    戴峰; 高歌军; 文颂; 颜利辉

    2009-01-01

    目的 探讨将三维CT脑灌注加权成像(PWM)和脑灌注血容量成像(PBV)整合优化到急性缺血性脑梗死脑CT灌注成像(CTP)联合脑CT血管成像(CTA)扫描方案中的价值.方法 对23例临床诊断急性脑梗死患者行CTP联合CTA检查,将增强CTA原始数据或增强CTA与平扫CTA减影的原始数据通过图像工作站处理,得到脑三维CT PWM和三维CT全脑PBV的伪彩图像,评价CTP与PWM、PBV在诊断急性脑梗死上的敏感性和整合运用的意义. 结果 23例临床诊断急性脑梗死患者,9例单纯CTP图像显示阴性患者中有7例在PWM、PBV图像上有阳性改变;单纯CTP观测急性脑梗死的敏感性约60.87%,CTP与PWM、PBV整合观测急性脑梗死的敏感性约91.30%. 结论 将三维CT脑PWM和脑PBV整合优化到急性脑梗死CT检查方案中,不仅能提高急性脑梗死的检出率,而且能预测患者预后.%Objective To assess the value of whole cerebral perfusion weighted map (PWM) and whole cerebral perfusion blood volume (PBV) integrating in scan protocol about CT perfusion (CTP) combined with CT angiography (CTA) in acute cerebral infarction. Methods Twenty-three patients with acute cerebral infarction proved clinically underwent CTP examination combined with CTA. The color-coded images of PWM and PBV were attained using workstation, and the raw data of contract CTA images and subtractive images between contract CTA and non-contract CTA were processed. The diagnostic sensitivity and the value of CTP and PWM, PBV integrating CTP in acute cerebral infraction were evaluated. Results Seven of 9 patients with negative results on CTP images had positive expressions on PWM and PBV images. The sensitivity of CTP was 60.87% and the sensitivity of PWM and PBV integrating CTP was 91.30%. Conclusion The scan protocol of PWM, PBV integrating CTP not only increases detection rate of acute cerebral infraction, but also has ability to predict the clinical prognosis of patients with cerebral

  4. 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...

  5. Carótida comum como via de estabelecimento da circulação extracorpórea para perfusão sistêmica e cerebral seletiva na correção das doenças da aorta Carotid artery inflow and anterograde cerebral perfusion in operations to correct aortic disease

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Pamplona Corte Real de Carvalho

    2006-09-01

    Full Text Available OBJETIVO: Analisar os resultados da utilização da artéria carótida comum direita no estabelecimento da circulação extracorpórea (CEC para perfusão sistêmica (PS, bem como na utilização como via anterógrada para proteção cerebral (PC, nos pacientes submetidos à correção das doenças que envolveram a aorta ascendente (AA. MÉTODO: Foram operados 23 pacientes portadores de várias afecções da AA, nos quais a abordagem foi possível por meio do estabelecimento da CEC pela anastomose de um tubo de PTFE (politetrafluoretileno à artéria carótida comum direita e manutenção de fluxo cerebral anterógrado durante a confecção da anastomose distal. O tempo médio de CEC foi de 195 minutos (152 a 253 minutos, a temperatura média sistêmica foi de 24ºC (18ºC a 25ºC, hipofluxo cerebral anterógrado, com média de 29 minutos (27 a 51 minutos e o tempo de internação média foi de 18 dias (8 a 30 dias. RESULTADOS: Todos os pacientes despertaram nas primeiras 48 horas sem dano neurológico. Por ocasião da pré-alta, foram submetidos ao teste MINI MENTAL STATE EXAMINATION (MMSE, que demonstrou não haver desordens cognitivas com dano neurológico. Ocorreram dois casos de infecção pulmonar, dois pacientes necessitaram de diálise e ocorreram dois óbitos relacionados à gravidade dos casos. Não houve óbito per-operatório. CONCLUSÃO: Este é um método prático, rápido, seguro, eficaz e reprodutível, tanto no estabelecimento da CEC como da proteção cerebral anterógrada, reduzindo o risco de isquemia cerebral, alterando a história natural da evolução pós-operatória destas correções.OBJECTIVE: To evaluate the use of the right common carotid artery to establish cardiopulmonary bypass (CPB and the use of anterograde cerebral perfusion as cerebral protection in patients scheduled for ascending aortic repair surgery. METHOD: Twenty-three patients were submitted to aortic repair because of different aortic diseases. In all

  6. 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.

  7. 慢性大脑中动脉狭窄或闭塞的CT灌注成像%CT perfusion imaging in patients with chronic middle cerebral artery stenosis or occlusion

    Institute of Scientific and Technical Information of China (English)

    苏凯燕; 刘增韬

    2012-01-01

    Objective To evaluate the blood perfusion character of chronic middle cerebral artery stenosis or occlusion with CT perfusion imaging. Methods The clinical and imaging dala of 11 cases with unilateral chronic middle cerebral artery stenosis or occlusion were collected. All cases were examined with CT perfusion and MR (MR1 and MKA). Results The CT perfusion character of chronic middle cerebral artery stenosis or occlusion included CBV elevated, CBF decreased, and MTI prolonged. Conclusion CT perfusion imaging can describe the blood perfusion character of chronic middle cerebral artery stenosis or occlusion, and provide theoretical basis for therapeutic plan.%目的 利用CT灌注成像技术研究慢性大动脉狭窄或闭塞患者的脑血流灌注特征.方法 搜集具有完整临床资料的单侧慢性大脑中动脉重度狭窄或闭寨患者11例,行CT灌注成像及磁共振(MRI及MRA)检查.结果 慢性大脑中动脉狭窄或闭塞患者的脑CT灌注特征是患侧脑血流量(CBF)降低,脑血容量(CBV)升高,平均通过时间(MTT)延长.结论 CT灌注成像能反映慢性大脑中动脉狭窄或闭塞患者的脑血流灌注特征,为临床治疗方案的制订提供理论依据.

  8. 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

    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...

  9. 64层螺旋CT脑灌注成像联合CT血管造影评价颅内外血管搭桥术后疗效%Assessment of cerebral internal and external vascular bypass graft in patients with single middle cerebral artery stenosis or occlusion by combining 64-row CT cerebral perfusion with angiography

    Institute of Scientific and Technical Information of China (English)

    陈天金; 朱栓庄; 温有信; 王耀彬; 韩向东; 白莹; 于旋

    2012-01-01

    Objective To assess the curative effect of cerebral internal and external vascular bypass graft in patients with sin -gle middle cerebral artery (MCA) stenosis or occlusion by combining 64 -row CT cerebral perfusion (CTP) with angiography ( CTA ). Methods Patients with middle cerebral artery stenosis or occlusion were recruited and underwent superficial temporal artery and mid -die cerebral artery(STA -MCA) bypass graft between March 2009 and Mar 2011. CTP and CTA examinations were performed in all patients before and after operation. The cerebral perfusion parameters were analyzed quantitatively and qualitatively . The origin, travel and anastomotic stoma of bypass grafts were evaluated by reconstructed CTA images . Results 46 patients were found with severe MCA stenosis or occlusion. The time to peak (TTP) and relative mean transit time (rMTT) images before therapy displayed the existence of perfusion delay. The relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCRV) images did not change significantly. The decrease of TTP and rMTT after therapy was of statistical significance ( P 0.05). In reconstructed CTA images , 82 bridge vessels were well displayed, including double bridges in 39 patients. The accuracy of CTA examination was 96.5%. All the bypass grafts were well shown and the anastomotic stomas were unobstructed. Conclusions It is feasible to evaluate the curative effects of cerebral internal and ex — ternal vascular bypass graft by combining CTP images of cerebral perfusion after therapy with CTA images of cerebral internal and exter -nal bypass grafts.%目的 探讨64层螺旋CT脑灌注成像(CT perfusion,CTP)联合CT血管造影(CT angiography,CTA)评价单侧大脑中动脉(middle cerebral artery,MCA)重度狭窄(闭塞)颅内外血管搭桥术后疗效的可行性.方法 46例拟行颅内外血管搭桥术患者,术前、后均行CTP及CTA检查.计算脑灌注参数图,对治疗前后脑灌注参数进行定量和定性对

  10. Altered phase interactions between spontaneous blood pressure and flow fluctuations in type 2 diabetes mellitus: Nonlinear assessment of cerebral autoregulation

    Science.gov (United States)

    Hu, Kun; Peng, C. K.; Huang, Norden E.; Wu, Zhaohua; Lipsitz, Lewis A.; Cavallerano, Jerry; Novak, Vera

    2008-04-01

    Cerebral autoregulation is an important mechanism that involves dilatation and constriction in arterioles to maintain relatively stable cerebral blood flow in response to changes of systemic blood pressure. Traditional assessments of autoregulation focus on the changes of cerebral blood flow velocity in response to large blood pressure fluctuations induced by interventions. This approach is not feasible for patients with impaired autoregulation or cardiovascular regulation. Here we propose a newly developed technique-the multimodal pressure-flow (MMPF) analysis, which assesses autoregulation by quantifying nonlinear phase interactions between spontaneous oscillations in blood pressure and flow velocity during resting conditions. We show that cerebral autoregulation in healthy subjects can be characterized by specific phase shifts between spontaneous blood pressure and flow velocity oscillations, and the phase shifts are significantly reduced in diabetic subjects. Smaller phase shifts between oscillations in the two variables indicate more passive dependence of blood flow velocity on blood pressure, thus suggesting impaired cerebral autoregulation. Moreover, the reduction of the phase shifts in diabetes is observed not only in previously-recognized effective region of cerebral autoregulation (type 2 diabetes mellitus alters cerebral blood flow regulation over a wide frequency range and that this alteration can be reliably assessed from spontaneous oscillations in blood pressure and blood flow velocity during resting conditions. We also show that the MMPF method has better performance than traditional approaches based on Fourier transform, and is more suitable for the quantification of nonlinear phase interactions between nonstationary biological signals such as blood pressure and blood flow.

  11. 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

    -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 controls......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....... There was no statistical difference in the healthy controls, consistent with previous findings. These results may indicate that the heat-washout method can be used as an alternative to strain gauge blood pressure in the evaluation of peripheral artery disease and wound healing potentials. Furthermore, the heat...

  12. 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

  13. 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.

  14. Automated versus manual post-processing of perfusion-CT data in patients with acute cerebral ischemia: influence on interobserver variability

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Bruno P.; Bhogal, Sumail; Dillon, William P.; Wintermark, Max [University of California, Department of Radiology, Neuroradiology Section, 505 Parnassus Avenue, Box 0628, San Francisco, CA (United States); Dankbaar, Jan Willem [University of California, Department of Radiology, Neuroradiology Section, 505 Parnassus Avenue, Box 0628, San Francisco, CA (United States); University Medical Center, Department of Radiology, Utrecht (Netherlands); Bredno, Joerg [Philips Research North America, San Francisco, CA (United States); Cheng, SuChun [University of California, Department of Epidemiology and Biostatistics, San Francisco, CA (United States)

    2009-07-15

    The purpose of this study is to compare the variability of PCT results obtained by automatic selection of the arterial input function (AIF), venous output function (VOF) and symmetry axis versus manual selection. Imaging data from 30 PCT studies obtained as part of standard clinical stroke care at our institution in patients with suspected acute hemispheric ischemic stroke were retrospectively reviewed. Two observers performed the post-processing of 30 CTP datasets. Each observer processed the data twice, the first time employing manual selection of AIF, VOF and symmetry axis, and a second time using automated selection of these same parameters, with the user being allowed to adjust them whenever deemed appropriate. The volumes of infarct core and of total perfusion defect were recorded. The cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and blood-brain barrier permeability (BBBP) values in standardized regions of interest were recorded. Interobserver variability was quantified using the Bland and Altman's approach. Automated post-processing yielded lower coefficients of variation for the volume of the infarct core and the volume of the total perfusion defect (15.7% and 5.8%, respectively) compared to manual post-processing (31.0% and 12.2%, respectively). Automated post-processing yielded lower coefficients of variation for PCT values (11.3% for CBV, 9.7% for CBF, and 9.5% for MTT) compared to manual post-processing (23.7% for CBV, 32.8% for CBF, and 16.7% for MTT). Automated post-processing of PCT data improves interobserver agreement in measurements of CBV, CBF and MTT, as well as volume of infarct core and penumbra. (orig.)

  15. Therapeutic Effects of Tongxinluo Capsule(通心络胶囊) on Patients with Acute Small Cerebral Infarction and Its Influence on SPECT Brain Perfusion Image

    Institute of Scientific and Technical Information of China (English)

    周盛年; 周国钰; 刘黎青

    2004-01-01

    Objective: To investigate the influence of Tongxinluo capsule (TXL, 通心络胶囊) on regional cerebral blood flow (rCBF) with 99mTc-ECD single photon emission computed tomography ( SPECT) brain perfusion imaging, and to observe the therapeutic effects of TXL on acute small cerebral infarction (ASCI).Methods: Thirty-four patients with ASCI were enrolled and randomly divided into two groups: the control group ( n = 17) was treated with the conventional treatment, i.e. 1.0g of Citicoline added into 300 mi normal saline for intravenous dripping daily for 2 weeks and 0.8 g of Piracetam taken three times a day orally for 4 weeks, and the treatment group ( n = 17)was treated additionally with 4 TXL capsules three times a day for 4 weeks besides the conventional treatment. The 99mTc-ECD SPECT brain perfusion imaging was performed before and after treatment to observe the change of rCBF, and the neurological deficit was evaluated by Edinburgh-Scandinavia stroke scale (SSS) scores and Barthel index (BI) at the same time. Results: After treatment, the rCBF in the treatment group was significantly improved ( P<0.01), while that in the control group remained unchanged, with the comparison of the rCBF in the two groups after treatment showing significant difference (P<0.01). In addition, the SSS score was significantly lower and BI significantly higher in the treatment group than those in the control group respectively after treatment. Conclusion: TXL could effectively improve rCBF and lessen the neurological deficit symptoms in patients with ASCI.

  16. Timing-invariant reconstruction for deriving high-quality CT angiographic data from cerebral CT perfusion data.

    NARCIS (Netherlands)

    Smit, E.J.; Vonken, E.J.; Schaaf, I.C. van der; Mendrik, A.M.; Dankbaar, J.W.; Horsch, A.D.; Seeters, T. van; Ginneken, B. van; Prokop, M.

    2012-01-01

    PURPOSE: To suggest a simple and robust technique used to reconstruct high-quality computed tomographic (CT) angiographic images from CT perfusion data and to compare it with currently used CT angiography techniques. MATERIALS AND METHODS: Institutional review board approval was waived for this retr

  17. 颅脑CTP对Willis环后循环变异脑血流灌注的评价%Using craniocerebral CT perfusion imaging to evaluate the cerebral blood flow perfusion of the posterior circulation variation of scull base arterial cycle

    Institute of Scientific and Technical Information of China (English)

    陈穹; 汪茂文; 王钢; 邹立巍; 郑穗生

    2015-01-01

    利用头颈CT血管成像( CTA )技术筛查出单侧颅底动脉环后循环变异患者,分为变异优势侧组和劣势侧组,再根据前循环是否有变异分为前循环完整组和非完整组,后运用颅脑CT灌注( CTP)技术分别测量两组双侧大脑后动脉供血区域脑组织血容量( CBV)、脑组织血流量( CBF)、平均通过时间(MTT)、造影剂达峰时间(TTD)数据,运用统计学方法对优势侧和劣势侧进行配对t检验. 90例颅底动脉环后循环变异的患者中右侧后交通动脉发育不良或缺失30例,右侧大脑后动脉发育不良或缺失5例,左侧大脑后交通动脉纤细或缺失49例,左侧大脑后动脉缺失6 例. 前循环完整组73例;前循环非完整组17例,其中7例为前交通动脉缺失,10例为单侧大脑前动脉A1段发育不良. 前循环完整组后循环优势侧CBV、CBF、MTT、TTD与劣势侧各组经配对t检验,差异无统计学意义;前循环非完整组后循环优势侧CBV、TTD与劣势侧经配对t检验,差异无统计学意义,MTT、TTD 两组间比较差异有统计学意义( P<0. 05 ). 在前循环完整组,颅底动脉环后循环变异劣势侧与优势侧脑血流灌注无明显差异;在前循环非完整组,颅底动脉环后循环变异劣势侧MTT大于优势侧,CBF小于优势侧,与临床不明原因的晕厥可能有相关作用.%To assess the cerebral blood flow perfusion of basicranial artery posterior circulation variation with the combined application of head and neck CT angiography ( CTA) and craniocerebral CT perfusion ( CTP) . Patients suffering posterior communicating artery variation in unilateral basicranial arterious circle were screened out with head and neck CTA, and divided into advantageous variation-side group and disadvantageous variation-side group. Then based on whether or not there was anterior circulation variation, the patients were divided into intact anterior circulation group and non- intact anterior circulation group. With

  18. Continuous Monitoring of Cerebrovascular Reactivity Using Pulse Waveform of Intracranial Pressure

    NARCIS (Netherlands)

    Aries, M.J.H.; Czosnyka, Marek; Budohoski, Karol P.; Kolias, Angelos G.; Radolovich, Danila K.; Lavinio, Andrea; Pickard, John D.; Smielewski, Peter

    2012-01-01

    Guidelines for the management of traumatic brain injury (TBI) call for the development of accurate methods for assessment of the relationship between cerebral perfusion pressure (CPP) and cerebral autoregulation and to determine the influence of quantitative indices of pressure autoregulation on out

  19. Effects of the cardiopulmonary of selective profound hypothermia and antegrade cerebral perfusion on ischemic brain%选择性深低温断血流对心肺等重要器官的影响

    Institute of Scientific and Technical Information of China (English)

    牛小群; 范耀东; 高永军; 付国平; 方绍龙; 曹毅; 徐蔚; 蒲军

    2012-01-01

    temperature maintained 32.5±0.58. Cerebral blood recovered after 70 minutes of cerebral ischemia. Other three monkeys had cerebral perfusion of 37℃ lingers liquid with similar methods. The brains and cardiopul-monary were examined by microscopy.EEG was examined before and after operation, the temperature, heart, breath, blood pressure were monitored during the operation, the scales of central nervous system were done every day. RESULTS In selective profound hypothermia group, heart and blood pressure were steady during the operation, and all of them survived forever after filled 70 minutes. The functions of neurological were normal after experiment. The EEG was normal after operation.There were no histology abnormities in brain, cardiopulmonary. The others of normothermia group did not recovery after filled 60 minutes and died, and there were different histology abnormities in brain, cardiopulmonary. CONCLUSION Selective profound hypothem-nia and antegrade cerebral perfusion of brain can inhibit ischemic injury and avoid severer cardiopulmonary complications.

  20. Comparison of cerebral blood flow data obtained by computed tomography (CT) perfusion with that obtained by xenon CT using 320-row CT.

    Science.gov (United States)

    Takahashi, Satoshi; Tanizaki, Yoshio; Kimura, Hiroaki; Akaji, Kazunori; Kano, Tadashige; Suzuki, Kentaro; Takayama, Youhei; Kanzawa, Takao; Shidoh, Satoka; Nakazawa, Masaki; Yoshida, Kazunari; Mihara, Ban

    2015-03-01

    Cerebral blood flow (CBF) data obtained by computed tomography perfusion (CTP) imaging have been shown to be qualitative data rather than quantitative, in contrast with data obtained by other imaging methods, such as xenon CT (XeCT) imaging. Thus, interpatient comparisons of CBF values themselves obtained by CTP may be inaccurate. In this study, we have compared CBF ratios as well as CBF values obtained from CTP-CBF data to those obtained from XeCT-CBF data for the same patients to determine CTP-CBF parameters that can be used for interpatient comparisons. The data used in the present study were obtained as volume data using 320-row CT. The volume data were applied to an automated region of interest-determining software (3DSRT, version 3.5.2 ) and converted to 59 slices of 2 mm interval standardized images. In the present study, we reviewed 10 patients with occlusive cerebrovascular diseases (CVDs) undergoing both CTP and XeCT in the same period. Our study shows that ratios of CBF measurements, such as hemodynamic stress distribution (perforator-to-cortical flow ratio of middle cerebral artery [MCA] region) or the left/right ratio for the region of the MCA, calculated using CTP data have been shown to correlate well with the same ratios calculated using XeCT data. These results suggest that such CBF ratios could be useful for generating interpatient comparisons of CTP-CBF data obtained by 320-row CT among patients with occlusive CVD.

  1. 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 amplitudes obtained in the experimental, left eye, and the control, right eye. Quantitative histology was performed to measure the survival of ganglion cells, amacrine cells and horizontal cells 2-6 weeks after the ischemic insult. An OPP of 5 mm Hg for 2h induced significant reductions in the amplitudes...

  2. 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

    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......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......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...

  3. Cerebral vascular control and metabolism in heat stress

    DEFF Research Database (Denmark)

    Bain, Anthony R; Nybo, Lars; Ainslie, Philip N

    2015-01-01

    This review provides an in-depth update on the impact of heat stress on cerebrovascular functioning. The regulation of cerebral temperature, blood flow, and metabolism are discussed. We further provide an overview of vascular permeability, the neurocognitive changes, and the key clinical implicat...... thermoregulatory control-for example, spinal cord injury, elderly, and those with preexisting cardiovascular diseases. © 2015 American Physiological Society. Compr Physiol 5:1345-1380, 2015.......This review provides an in-depth update on the impact of heat stress on cerebrovascular functioning. The regulation of cerebral temperature, blood flow, and metabolism are discussed. We further provide an overview of vascular permeability, the neurocognitive changes, and the key clinical...... peripheral resistance secondary to skin vasodilatation. Therefore, when hyperthermia is combined with conditions that increase cardiovascular strain, for example, orthostasis or dehydration, the inability to preserve cerebral perfusion pressure further reduces CBF. A reduced cerebral perfusion pressure...

  4. 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

  5. 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.)

  6. 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.

  7. 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.)

  8. 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...

  9. 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

  10. Dynamic cerebral autoregulation to induced blood pressure changes in human experimental and clinical sepsis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Plovsing, Ronni R; Bailey, Damian M;

    2016-01-01

    Previous studies have demonstrated that dynamic cerebral autoregulation to spontaneous fluctuations in blood pressure is enhanced following lipopolysaccharide (LPS) infusion, a human experimental model of early sepsis, whereas by contrast it is impaired in patients with severe sepsis or septic......R). This was performed before and after LPS infusion in healthy volunteers, and within 72 h following clinical diagnosis of sepsis in patients. In healthy volunteers, thigh-cuff deflation caused a MAP reduction of 16 (13-20) % at baseline and 18 (16-20) % after LPS, while the MAP reduction was 12 (11-13) % in patients......(-1) ; P = 0·91 versus baseline; P = 0·14 versus LPS]. While our findings support the concept that dynamic cerebral autoregulation is enhanced during the very early stages of sepsis, they remain inconclusive with regard to more advanced stages of disease, because thigh-cuff deflation failed to induce...

  11. Changes of splanchnic perfusion after applying positive end expiratory pressure in patients with acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Sarkar Suman

    2009-01-01

    Full Text Available Background: Positive end-expiratory pressure (PEEP improves oxygenation and can prevent ventilator- induced lung injury in patients with acute respiratory distress syndrome (ARDS. Nevertheless, PEEP can also induce detrimental effects by its influence on the cardiovascular system. The purpose of this study was to assess the effects of PEEP on gastric mucosal perfusion while applying a protective ventilatory strategy in patients with ARDS. Materials and Methods: Thirty-two patients were included in the study. A pressure-volume curve was traced and ideal PEEP, defined as lower inflection point + 2cmH 2 O, was determined. Gastric tonometry was measured continuously (Tonocap. After baseline measurements, 10, 15 and 20cmH 2 O PEEP and ideal PEEP were applied for 30 min each. By the end of each period, hemodynamics, CO 2 gap (gastric minus arterial partial pressures, and ventilatory measurements were taken. Results: PEEP had no effect on CO 2 gap (median [range], baseline: 18 [2-30] mmHg; PEEP 10: 18 [0-40] mmHg; PEEP 15: 17 [0-39] mmHg; PEEP 20: 16 [4-39] mmHg; ideal PEEP: 19 [9-39] mmHg; P = 0.19. Cardiac index also remained unchanged (baseline: 4.7 [2.6-6.2] l min−1 m−2 ; PEEP 10: 4.4 [2.5-7] l min−1 m−2 ; PEEP 15: 4.4 [2.2-6.8] l min−1 m−2 ; PEEP 20: 4.8 [2.4-6.3] l min−1 m−2 ; ideal PEEP: 4.9 [2.4-6.3] l min−1 m−2 ; P = 0.09. Conclusion: PEEP of 10-20 cmH 2 O does not affect splanchnic perfusion and is hemodynamically well tolerated in most patients with ARDS, including those receiving inotropic supports.

  12. CT perfusion imaging in the management of posterior reversible encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Casey, S.O.; McKinney, A.; Teksam, M.; Liu, H.; Truwit, C.L. [Department of Radiology, University of Minnesota Medical School, 420 Delaware Street SE, Box 292, MN 55455, Minneapolis (United States)

    2004-04-01

    A 13-year-old girl with a renal transplant presented with hypertension and seizures. CT and MRI demonstrated typical bilateral parietal, occipital and posterior frontal cortical and subcortical edema, thought to represent posterior reversible encephalopathy syndrome. The cause was presumed to be hypertension. Antihypertensive therapy was started, lowering of the blood pressure in the range of 110-120 mmHg systolic. However, stable xenon (Xe) CT perfusion imaging revealed ischemia within the left parietal occipital region. The antihypertensive was adjusted which increased both the systolic and diastolic blood pressure by 31 mm Hg. The patient was re-imaged with Xe CT and was found to have resolution of the ischemic changes within the left parietal occipital region. In this report, we present a case in which stable Xe CT was used to monitor the degree of cerebral perfusion and guide titration of antihypertensive therapy. Such brain perfusion monitoring may have helped to prevent infarction of our patient. (orig.)

  13. Reliability of cranial CT versus intracerebral pressure measurement for the evaluation of generalised cerebral oedema in children

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, W.; Beck, R.; Behrmann, C.; Spielmann, R.P. [Department of Diagnostic Radiology, University Hospital Halle-Wittenberg, 06 097 Halle (Germany); Schobess, A. [Department of Pediatrics, University Hospital Halle-Wittenberg, 06097 Halle (Germany)

    2000-07-01

    Objective. To examine the extent to which intracranial pressure (ICP) in children after severe brain trauma can be determined by cranial CT. Materials and methods. Two experienced paediatric radiologists, without any knowledge of the clinical symptoms, evaluated 124 CT scans from 65 children (average age 5.4 years) who underwent intracranial measurement of their cerebral pressure. Results. CT had high sensitivity (99.1%) for 'high cerebral pressure' but a much lower specificity (78.1%). The examiners tended to estimate ICP as 'high' even when actual ICP was low. Since therapy for lowering cerebral pressure involves potential risks, actual cerebral pressure measurement, particularly in children, should be considered before intervention (e. g. hyperventilation or trepanation). We report the change in different intracerebral fluid compartments with varying cerebral pressure and modifications of the density of the brain tissue in an inter- and intraobserver comparison. Conclusion. The radiologist cannot differentiate, for methodological reasons, between a change in the intracranial fluid compartments not associated with a change in ICP and one in which it is critically elevated. Before any interventional treatments such as decompression-trepanation or hyperventilation are instituted, measurement of ICP should be considered, especially in children. (orig.)

  14. 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.

  15. 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

  16. 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 ...

  17. 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...

  18. Absolute Cerebral Blood Flow Infarction Threshold for 3-Hour Ischemia Time Determined with CT Perfusion and 18F-FFMZ-PET Imaging in a Porcine Model of Cerebral Ischemia.

    Science.gov (United States)

    Wright, Eric A; d'Esterre, Christopher D; Morrison, Laura B; Cockburn, Neil; Kovacs, Michael; Lee, Ting-Yim

    2016-01-01

    CT Perfusion (CTP) derived cerebral blood flow (CBF) thresholds have been proposed as the optimal parameter for distinguishing the infarct core prior to reperfusion. Previous threshold-derivation studies have been limited by uncertainties introduced by infarct expansion between the acute phase of stroke and follow-up imaging, or DWI lesion reversibility. In this study a model is proposed for determining infarction CBF thresholds at 3hr ischemia time by comparing contemporaneously acquired CTP derived CBF maps to 18F-FFMZ-PET imaging, with the objective of deriving a CBF threshold for infarction after 3 hours of ischemia. Endothelin-1 (ET-1) was injected into the brain of Duroc-Cross pigs (n = 11) through a burr hole in the skull. CTP images were acquired 10 and 30 minutes post ET-1 injection and then every 30 minutes for 150 minutes. 370 MBq of 18F-FFMZ was injected ~120 minutes post ET-1 injection and PET images were acquired for 25 minutes starting ~155-180 minutes post ET-1 injection. CBF maps from each CTP acquisition were co-registered and converted into a median CBF map. The median CBF map was co-registered to blood volume maps for vessel exclusion, an average CT image for grey/white matter segmentation, and 18F-FFMZ-PET images for infarct delineation. Logistic regression and ROC analysis were performed on infarcted and non-infarcted pixel CBF values for each animal that developed infarct. Six of the eleven animals developed infarction. The mean CBF value corresponding to the optimal operating point of the ROC curves for the 6 animals was 12.6 ± 2.8 mL·min-1·100g-1 for infarction after 3 hours of ischemia. The porcine ET-1 model of cerebral ischemia is easier to implement then other large animal models of stroke, and performs similarly as long as CBF is monitored using CTP to prevent reperfusion.

  19. Absolute Cerebral Blood Flow Infarction Threshold for 3-Hour Ischemia Time Determined with CT Perfusion and 18F-FFMZ-PET Imaging in a Porcine Model of Cerebral Ischemia.

    Directory of Open Access Journals (Sweden)

    Eric A Wright

    Full Text Available CT Perfusion (CTP derived cerebral blood flow (CBF thresholds have been proposed as the optimal parameter for distinguishing the infarct core prior to reperfusion. Previous threshold-derivation studies have been limited by uncertainties introduced by infarct expansion between the acute phase of stroke and follow-up imaging, or DWI lesion reversibility. In this study a model is proposed for determining infarction CBF thresholds at 3hr ischemia time by comparing contemporaneously acquired CTP derived CBF maps to 18F-FFMZ-PET imaging, with the objective of deriving a CBF threshold for infarction after 3 hours of ischemia. Endothelin-1 (ET-1 was injected into the brain of Duroc-Cross pigs (n = 11 through a burr hole in the skull. CTP images were acquired 10 and 30 minutes post ET-1 injection and then every 30 minutes for 150 minutes. 370 MBq of 18F-FFMZ was injected ~120 minutes post ET-1 injection and PET images were acquired for 25 minutes starting ~155-180 minutes post ET-1 injection. CBF maps from each CTP acquisition were co-registered and converted into a median CBF map. The median CBF map was co-registered to blood volume maps for vessel exclusion, an average CT image for grey/white matter segmentation, and 18F-FFMZ-PET images for infarct delineation. Logistic regression and ROC analysis were performed on infarcted and non-infarcted pixel CBF values for each animal that developed infarct. Six of the eleven animals developed infarction. The mean CBF value corresponding to the optimal operating point of the ROC curves for the 6 animals was 12.6 ± 2.8 mL·min-1·100g-1 for infarction after 3 hours of ischemia. The porcine ET-1 model of cerebral ischemia is easier to implement then other large animal models of stroke, and performs similarly as long as CBF is monitored using CTP to prevent reperfusion.

  20. Absolute Cerebral Blood Flow Infarction Threshold for 3-Hour Ischemia Time Determined with CT Perfusion and 18F-FFMZ-PET Imaging in a Porcine Model of Cerebral Ischemia.

    Science.gov (United States)

    Wright, Eric A; d'Esterre, Christopher D; Morrison, Laura B; Cockburn, Neil; Kovacs, Michael; Lee, Ting-Yim

    2016-01-01

    CT Perfusion (CTP) derived cerebral blood flow (CBF) thresholds have been proposed as the optimal parameter for distinguishing the infarct core prior to reperfusion. Previous threshold-derivation studies have been limited by uncertainties introduced by infarct expansion between the acute phase of stroke and follow-up imaging, or DWI lesion reversibility. In this study a model is proposed for determining infarction CBF thresholds at 3hr ischemia time by comparing contemporaneously acquired CTP derived CBF maps to 18F-FFMZ-PET imaging, with the objective of deriving a CBF threshold for infarction after 3 hours of ischemia. Endothelin-1 (ET-1) was injected into the brain of Duroc-Cross pigs (n = 11) through a burr hole in the skull. CTP images were acquired 10 and 30 minutes post ET-1 injection and then every 30 minutes for 150 minutes. 370 MBq of 18F-FFMZ was injected ~120 minutes post ET-1 injection and PET images were acquired for 25 minutes starting ~155-180 minutes post ET-1 injection. CBF maps from each CTP acquisition were co-registered and converted into a median CBF map. The median CBF map was co-registered to blood volume maps for vessel exclusion, an average CT image for grey/white matter segmentation, and 18F-FFMZ-PET images for infarct delineation. Logistic regression and ROC analysis were performed on infarcted and non-infarcted pixel CBF values for each animal that developed infarct. Six of the eleven animals developed infarction. The mean CBF value corresponding to the optimal operating point of the ROC curves for the 6 animals was 12.6 ± 2.8 mL·min-1·100g-1 for infarction after 3 hours of ischemia. The porcine ET-1 model of cerebral ischemia is easier to implement then other large animal models of stroke, and performs similarly as long as CBF is monitored using CTP to prevent reperfusion. PMID:27347877

  1. Functional Heart Valve Scaffolds Obtained by Complete Decellularization of Porcine Aortic Roots in a Novel Differential Pressure Gradient Perfusion System.

    Science.gov (United States)

    Sierad, Leslie Neil; Shaw, Eliza Laine; Bina, Alexander; Brazile, Bryn; Rierson, Nicholas; Patnaik, Sourav S; Kennamer, Allison; Odum, Rebekah; Cotoi, Ovidiu; Terezia, Preda; Branzaniuc, Klara; Smallwood, Harrison; Deac, Radu; Egyed, Imre; Pavai, Zoltan; Szanto, Annamaria; Harceaga, Lucian; Suciu, Horatiu; Raicea, Victor; Olah, Peter; Simionescu, Agneta; Liao, Jun; Movileanu, Ionela; Harpa, Marius; Simionescu, Dan Teodor

    2015-12-01

    There is a great need for living valve replacements for patients of all ages. Such constructs could be built by tissue engineering, with perspective of the unique structure and biology of the aortic root. The aortic valve root is composed of several different tissues, and careful structural and functional consideration has to be given to each segment and component. Previous work has shown that immersion techniques are inadequate for whole-root decellularization, with the aortic wall segment being particularly resistant to decellularization. The aim of this study was to develop a differential pressure gradient perfusion system capable of being rigorous enough to decellularize the aortic root wall while gentle enough to preserve the integrity of the cusps. Fresh porcine aortic roots have been subjected to various regimens of perfusion decellularization using detergents and enzymes and results compared to immersion decellularized roots. Success criteria for evaluation of each root segment (cusp, muscle, sinus, wall) for decellularization completeness, tissue integrity, and valve functionality were defined using complementary methods of cell analysis (histology with nuclear and matrix stains and DNA analysis), biomechanics (biaxial and bending tests), and physiologic heart valve bioreactor testing (with advanced image analysis of open-close cycles and geometric orifice area measurement). Fully acellular porcine roots treated with the optimized method exhibited preserved macroscopic structures and microscopic matrix components, which translated into conserved anisotropic mechanical properties, including bending and excellent valve functionality when tested in aortic flow and pressure conditions. This study highlighted the importance of (1) adapting decellularization methods to specific target tissues, (2) combining several methods of cell analysis compared to relying solely on histology, (3) developing relevant valve-specific mechanical tests, and (4) in vitro testing

  2. 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.

  3. 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

  4. 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.

  5. Mean arterial pressure change associated with cerebral blood flow in healthy older adults.

    Science.gov (United States)

    Deverdun, Jeremy; Akbaraly, Tasnime N; Charroud, Celine; Abdennour, Meriem; Brickman, Adam M; Chemouny, Stephane; Steffener, Jason; Portet, Florence; Bonafe, Alain; Stern, Yaakov; Ritchie, Karen; Molino, François; Le Bars, Emmanuelle; Menjot de Champfleur, Nicolas

    2016-10-01

    We investigate over a 12-year period the association between regional cerebral blood flow (CBF) and cardiovascular risk factors in a prospective cohort of healthy older adults (81.96 ± 3.82 year-old) from the Cognitive REServe and Clinical ENDOphenotype (CRESCENDO) study. Cardiovascular risk factors were measured over 12 years, and gray matter CBF was measured at the end of the study from high-resolution magnetic resonance imaging using arterial spin labeling. The association between cardiovascular risk factors, their long-term change, and CBF was assessed using multivariate linear regression models. Women were observed to have higher CBF than men (p < 0.05). Increased mean arterial pressure (MAP) over the 12-year period was correlated with a low cerebral blood flow (p < 0.05, R(2) = 0.21), whereas no association was detected between CBF and MAP at the time of imaging. High levels of glycemia tended to be associated with low cerebral blood flow values (p < 0.05). Age, alcohol consumption, smoking status, body mass index, history of cardiovascular disease, and hypertension were not associated with CBF. Our main result suggests that change in MAP is the most significant predictor of future CBF in older adults.

  6. 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

  7. 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

  8. Mechanisms underlying phase lag between systemic arterial blood pressure and cerebral blood flow velocity.

    Science.gov (United States)

    Kuo, Terry B J; Chern, Chang-Ming; Yang, Cheryl C H; Hsu, Hung-Yi; Wong, Wen-Jang; Sheng, Wen-Yung; Hu, Han-Hwa

    2003-01-01

    To explore the mechanisms underlying the phase lag between oscillations in arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV), ABP and CBFV signals were recorded noninvasively from normal volunteers who lay quietly in a supine position. Mean ABP (MAP) and CBFV (MFV) were calculated beat-to-beat by means of integration. Cerebral vascular resistance (CVR) was calculated by dividing MAP with MFV. Frequency domain analysis of MAP, MFV and CVR signals revealed very-low frequency (VLF, 0.016-0.04 Hz), low-frequency (LF, 0.04-0.15 Hz), and high-frequency (HF, 0.15-0.4 Hz) components. The transfer phase of MAP-CVR coupling in the LF and HF range was frequency-dependent, which is equivalent to a time delay of 2 s. However, the transfer phase differed in the CVR-MFV coupling in that the phase was distributed around 180 degrees across the LF and HF ranges. Cross-correlation analysis revealed a positive relationship between MAP-CVR coupling, with MAP leading by 2 s, and a negative relationship between CVR-MFV coupling, with CVR leading by 0.3 s. We concluded that the phase lag between oscillations in ABP and CBFV was chiefly contributed to by the starting latency of cerebral autoregulation (i.e. cerebral vasomotion, revealed by MAP-CVR coupling). Moreover, the negative correlation of the CVR-MFV coupling could offer a different explanation for the physiologic significance of the phase lead of CBFV-ABP oscillations.

  9. Association of Cerebral Amyloidosis, Blood Pressure, and Neuronal Injury with Late-Life Onset Depression

    Science.gov (United States)

    Byun, Min Soo; Choe, Young Min; Sohn, Bo Kyung; Yi, Dahyun; Han, Ji Young; Park, Jinsick; Choi, Hyo Jung; Baek, Hyewon; Lee, Jun Ho; Kim, Hyun Jung; Kim, Yu Kyeong; Yoon, Eun Jin; Sohn, Chul-Ho; Woo, Jong Inn; Lee, Dong Young

    2016-01-01

    Previous literature suggests that Alzheimer's disease (AD) process may contribute to late-life onset depression (LLOD). Therefore, we investigated the association of LLOD with cerebral amyloidosis and neuronal injury, the two key brain changes in AD, along with vascular risks. Twenty nine non-demented individuals who first experienced major depressive disorder (MDD) after age of 60 years were included as LLOD subjects, and 27 non-demented elderly individuals without lifetime experience of MDD were included as normal controls (NC). Comorbid mild cognitive impairment (MCI) was diagnosed in 48% of LLOD subjects and in 0% of NC. LLOD, irrespective of comorbid MCI diagnosis, was associated with prominent prefrontal cortical atrophy. Compared to NC, LLOD subjects with comorbid MCI (LLODMCI) showed increased cerebral 11C-Pittsburg compound B (PiB) retention and plasma beta-amyloid 1–40 and 1–42 peptides, as measures of cerebral amyloidosis; and, such relationship was not observed in overall LLOD or LLOD without MCI (LLODwoMCI). LLOD subjects, particularly the LLODwoMCI, had higher systolic blood pressure (SBP) than NC. When analyzed in the same multiple logistic regression model that included prefrontal gray matter (GM) density, cerebral amyloidosis, and SBP as independent variables, only prefrontal GM density showed a significant independent association with LLOD regardless of MCI comorbidity status. Our findings suggest AD process might be related to LLOD via prefrontal neuronal injury in the MCI stage, whereas vascular processes—SBP elevation, in particular—are associated with LLOD via prefrontal neuronal injury even in cognitively intact or less impaired individuals. PMID:27790137

  10. 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

    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 system, preparation...

  11. 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

  12. The effect of ketanserin upon postoperative blood pressure, cerebral blood flow and oxygen metabolism in patients subjected to craniotomy for cerebral tumours.

    Science.gov (United States)

    Felding, M; Cold, G E; Jacobsen, C J; Stjernholm, P; Voss, K

    1995-07-01

    Hypertension and cerebral hyperperfusion are often seen in the immediate postoperative period after craniotomy for supratentorial tumours. This study was performed to evaluate the effect of ketanserin, given at the end of the peroperative period, upon cerebral blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2) before extubation. Mean arterial blood pressure (MABP), cerebral arterio-venous oxygen content difference (AVDO2), PaO2, and PaCO2 were repeatedly measured during the operation, and 180 minutes after extubation. Ten patients were included in this study. The results were compared to those from a recent study in which ten patients served as control. All patients were anaesthetized with thiopentone, fentanyl, nitrous oxide 67%, halothane 0.5% anesthesia. Ten patients were given ketanserin 10-20 mg (mean 18.5 mg) before extubation. There was no significant difference in CBF- and CMRO2 values between the two groups. During the period between closure of the dura and 5 minutes after extubation, an increase in MABP was observed in the control group (P < 0.05) but not in the ketanserin group. During the same period, a decrease in AVDO2 was observed in both groups (P < 0.05) and during the next 10 minutes an increase was observed. However, no difference in AVDO2 values between the two groups was found. These findings suggest that peroperative treatment with ketanserin reduces postoperative hypertension without influencing the cerebral blood flow or metabolism. PMID:7572004

  13. 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.

  14. The Interaction Between Heart Systole and Cerebral Circulation During Lower Body Negative Pressure Test.

    Science.gov (United States)

    Magdalena, Kasprowicz; Czosnyka, Marek; Diehl, Rolf R; Haubrich, Christina

    2016-01-01

    The time constant (τ[s]) estimates how fast the arterial part of the cerebrovascular bed fills with blood volume during the cardiac cycle, whereas a product of τ and heart rate (HR) (τ*HR[%]) assesses how this period of arterial filling is related to an entire heart cycle. In this study we aimed to investigate cerebral hemodynamics using τ and τ*HR during a progressive lower body negative pressure (LBNP) test.Transcranial Doppler cerebral blood flow velocity (CBFV), Finapres arterial blood pressure (ABP), and HR, along with end-tidal CO2, were simultaneously recorded in 38 healthy volunteers during an LBNP test. The τ was estimated using mathematical transformation of ABP and CBFV pulse waveforms. After a gradual shortening of τ from baseline (0.20 ± 0.06 s) to maximal LBNP before the onset of presyncope (0.15 ± 0.05 s), we observed a significant increase in τ at presyncope (0.24 ± 0.15 s; p = 0.0001). In the course of LBNP, the τ*HR did not significantly change from baseline (25.6 ± 5.7 % vs 26.6 ± 8.9 %, p = n.s.) except for presyncope, when it increased to 40.4 ± 21.1 % (p blood is prolonged during presyncope, an increased part of the heart cycle seems to be spent on the cerebral blood supply. PMID:27165894

  15. 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)

  16. 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

  17. 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

  18. 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

  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. Modelling of cerebral hyper-perfusion after chronic forebrain ischemia in rats%大鼠慢性前脑缺血解除后脑过度灌注模型的建立

    Institute of Scientific and Technical Information of China (English)

    肖玮; 王天龙; 李俊发; 赵磊; 于培兰; 孔萃萃

    2011-01-01

    目的 建立大鼠慢性前脑缺血基础上的脑过度灌注模型.方法 选取雄性Wistar大鼠72只依随机数字表均分为两个模型建造组.缺血模型采用双侧颈总动脉结扎,随机数字表分为空白对照、假手术组、缺血2周组、缺血4周组,每组9只,结扎前后分别测定脑额叶血流、比较各组行为学评分、脑梗死面积.过度灌注模型是在缺血模型基础上,再灌注同时经尾静脉持续输注去氧肾上腺素4μg·kg-1·min-1,使再灌注后脑额叶血流超过基础值的200%.随机分为空白对照组、盐水组、过度灌注0.5 h组、过度灌注2 h组,每组9只,再灌注前后分别测定脑额叶血流,比较各组行为学评分、血脑屏障通透性、脑干湿重比值.结果 大鼠双侧颈动脉结扎后前脑血流减少可达67%±2%,脑过度灌注组与盐水输注组的脑血流变化值差异有统计学意义(P<0.01).缺血2周组的神经功能评分、脑梗死面积与正常对照组差异无统计学意义,缺血4周组的脑梗死面积与正常对照组差异有统计学意义.脑过度灌注2 h组的血脑屏障通透性改变有统计学意义(P<0.05).结论 结扎大鼠双侧颈总动脉2周后脑过度灌注2 h可较好地建立大鼠脑过度灌注综合征模型.%Objective To establish the cerebral hyper-perfusion model after chronic forebrain ischemia in rats. Methods A total of 72 male rats were equally randomized into 2 modeling groups. The ligation of bilateral common carotid artery could induce chronic forebrain ischemia. And 36 rats were randomly grouped by ischemia duration: control group ( n = 9 ), sham group ( n = 9 ), 2-wcek ischemia group ( n = 9 ) and 4-wcek ischemia group ( n = 9 ). The blood flow in frontal lobe was measured at pre- and post-ligation. The neurological score and cerebral infarction area were also compared among the groups. The min-1 via tail vein to produce cerebrally hyperperfused blood flow rate over 200% of baseline

  1. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Young; Lee, Jae Sung; Kim, Seung Ki; Wang, Kyu Chang; Cho, Byung Kyu; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2008-06-15

    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

  3. 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.)

  4. 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.)

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

    Directory of Open Access Journals (Sweden)

    Anna Tietze

    Full Text Available 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.Seventy-two glioma patients (sixty high-grade, twelve low-grade gliomas were included. Capillary transit time heterogeneity (CTH and the coefficient of variation (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 was examined by the Cox proportional-hazards regression model, and by survival curves using log-rank tests.The best prediction of grade (AUC = 0.876; p < 0.05 was achieved by combining knowledge of CBV and CTH in the enhancing tumor and peri-focal edema, and patients with glioblastoma multiforme were identified best by CTH (AUC = 0.763; p<0.001. CTH outperformed CBV and COV in predicting time to progression and survival in all gliomas and in a subgroup consisting of only high-grade gliomas.Our study confirms the importance of microvascular flow control in tumor growth by demonstrating that determining CTH improves tumor grading and outcome prediction in glioma patients compared to CBV alone.

  6. CT Perfusion and MR Perfusion Weighted Imaging in Evaluating the Effect of Vascular Reconstruction on Short-term Cerebral Blood Flow in Patients with Moyamoya Disease%CT灌注与MR灌注加权成像评价烟雾病血管重建术对烟雾病患者短期脑血流的影响

    Institute of Scientific and Technical Information of China (English)

    崔若棣; 易明岗

    2015-01-01

    Objective To study CT perfusion (CTP) and MR perfusion (PWI) weighted imaging in evaluating the effect of vascular reconstruction on short-term cerebral blood flow in patients with moyamoya disease.Methods 47 patients with unilateral vascular reconstruction confirmed by DSA in the hospital were selected as the research objects and all received vascular reconstruction. All the patients received CTP and PWI examination before and after operation to obtain parameters, such as cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and time to peak (TTP). The preoperative and postoperative distribution of cerebral middle artery (MCA) and ipsilateral cerebellar perfusion parameters in control part (rCBF, rCBV, rMTT and rTTP) were compared as well as the differences in preoperative and postoperative relative value of CTP and PWI perfusion parameters.Results Postoperative CT perfusion image showed that CBF, CBV, MTT and TTP in the right distribution area of MCA significantly changed, compared with those before operation. Postoperative PWI perfusion image showed that CBF, CBV, MTT and TTP significantly significantly changed, compared with those before operation. After operation, rCBF and rCBV values in the distribution area of operation side MCA and the control ares were significantly higher than those before operation (P<0.05) while rMTT and rTTP were significantly lower than those before operation (P<0.05).Conclusion Both of CT perfusion and MR perfusion weighted imaging are the effective observation methods to observe the changes of cerebral blood flow in patients with moyamoya disease, which can be used in clinic.%目的:研究CT灌注(CTP)与MR灌注(PWI)加权成像评价烟雾病血管重建术对烟雾病患者短期脑血流的影响。方法选取我院47例经DSA证实的单侧血管重建术患者为研究对象,均行血管重建术治疗,术前术后接受CTP、PWI检查,获得脑血容量(CBV)、脑血流量(CBF)、平均通

  7. CT灌注成像对颅脑创伤病灶周围血流灌注的鉴别意义%The distinguishing meaning of CT perfusion on the blood perfusion of the area of cranio-cerebral trauma focus

    Institute of Scientific and Technical Information of China (English)

    戴君侠; 孙军; 陈茂华

    2015-01-01

    Objective: To explore the distinguishing meaning of CT perfusion (CTP) on the blood perfu-sion condition of the area of cranio-cerebral trauma focus.Methods: CT scanning was used in the patients with different cranio-cerebral trauma. Furthermore, CTP was used to examine those lesions with low-density shadow surrounding, while an analysis of the parameters of mean transit time (MTT), regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV), and a comparison of patient prognoses were also conducted. Results: CT scan showed low-density focus of the brain parenchyma around the site of the trauma in 79 cases; CT perfusion parameters showed hypo-perfusion of the brain tissue around the trauma in 42 cases (54.4%), high perfusion in 35 cases (44.3%), while there were no obvious brain tissue perfusion abnormalities in 2 cases. Prog-nosis of low perfusion was poorer.Conclusion: CT examination should apply further CTP in the case of those patients who have been found to display low-density shadow around their cranio-cerebral trauma, in order to help clinicians to better understand the local haemodynamic state of the brain tissue. This has great signiifcance on the diagnosis of focus microcirculation disturbance of cranio-cerebral trauma.%目的:探讨CT灌注成像(CTP)对颅脑创伤病灶周围组织血流灌注情况的鉴别意义。方法:对头颅CT扫描提示有脑挫裂伤病灶,且病灶周围存在低密度影的颅脑创伤患者79例行CTP检查,将每例的平均通过时间(MTT)、局部脑血流量(rCBF)、局部脑血容量(rCBV)等参数值和格拉斯哥预后评分(GOS)进行比较分析。结果:CTP显示创伤周围脑组织低灌注42例(占54.4%),高灌注35例(占44.3%),2例未见明显脑组织灌注异常。低灌注(rCRF、rCBV降低,MTT延长)者预后较差。结论:对CT检查发现颅脑创伤病灶周围低密度影患者进一步行CTP检查,能使临床医师了解脑

  8. 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

  9. Cerebral oxygenation and hyperthermia

    Directory of Open Access Journals (Sweden)

    Anthony Richard Bain

    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.

  10. 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

    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...

  11. [Automatic regulator of venous pressure and venous outflow in the perfusion system].

    Science.gov (United States)

    Smirnov, L M; Levinskiĭ, M M; Kharnas, S Sh; Cherniak, V A

    1976-01-01

    A scheme for automatic regulation of the venous pressure and venous blood outflow during extracorporeal circulation is proposed. The system consists of a photoelectric sensor placed on a tube led out of the major venous trunkline, a converter and an electromechanical eccentric clamp that compresses the venous trunkline, all of which secures stabilization of the controlled values.

  12. 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

  13. Application of stressed cerebral blood flow perfusion imaging in cerebrovascular disease%负荷试验脑血流灌注显像在脑血管疾病中的应用

    Institute of Scientific and Technical Information of China (English)

    尹立杰; 刘杰; 金超岭; 王荣福

    2016-01-01

    The incidence of ischemic cerebrovascular disease is currently high. The disease can be diagnosed and treated by numerous methods, including transcranial doppler, CT angiography, MRI, digital subtraction angiography and cerebral blood flow perfusion imaging of resting and stress states. In these methods, the clinical application of stressed cerebral blood flow perfusion imaging is very wide and includes vertical load tests, CO2 inhalation load tests, acetazolamide stress tests, dipyridamole stress tests, and adenosine stress tests. Stressed cerebral blood flow perfusion imaging can provide an objective basis for the early diagnosis, curative effect evaluation, prognostic estimation, and evaluation of brain reserve function.%目前,缺血性脑血管病发病率较高,对其诊治方法很多,包括经颅多普勒超声、 CT血管造影、 MRI、数字减影血管造影和静息及负荷试验脑血流灌注显像等。其中,负荷试验脑血流灌注显像包括直立负荷试验、 CO2吸入负荷试验、乙酰唑胺负荷试验、潘生丁负荷试验、腺苷负荷试验等,其临床应用非常广泛,为临床早期诊断、疗效评价、预后以及脑血流储备功能的评估提供了客观依据。

  14. Skin perfusion pressure measured by isotope washout in legs with arterial occlusive disease. Evaluation of different tracers, comparison to segmental systolic pressure, angiography and transcutaneous oxygen tension and variations during changes in systemic blood pressure

    DEFF Research Database (Denmark)

    Holstein, P; Trap-Jensen, J; Bagger, H;

    1983-01-01

    digit (strain gauge technique). The two different methods correlated statistically significant at all four levels, but the systolic blood pressures were higher than the SPP in particular in diabetic legs; (3) Angiograms in 35 legs with AOD showed that the SPP on the ankle was only consistently decreased......The skin perfusion pressure (SPP) measured as the isotope washout cessation external pressure is valuable in selection of major amputation level. Five methodological investigations important to clinical use were carried out: (1) In five normal legs and 10 legs with arterial occlusive disease (AOD......Hg (range 18-98) (P less than 0.02). The average washout constant for the three different tracers were approximately equal and correlated statistically significant with the SPP; (2) In 59 legs with AOD, segmental SPP was compared to segmental systolic blood pressures on the thigh, calf, ankle and first...

  15. 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

  16. 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

  17. 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...

  18. 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.

  19. 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

    patients undergoing serial examination after 7 (range, 2-10) days. Six of these patients had an uncomplicated course, one had a protracted recovery, and one died. Autoregulation was not restored in two patients; one died and one had a protracted recovery. CONCLUSION: In patients in the early phase of acute......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...... 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...

  20. The relationship between cardiac output, cerebral electrical activity, cerebral fractional oxygen extraction and peripheral blood flow in premature newborn infants.

    Science.gov (United States)

    Victor, Suresh; Appleton, Richard E; Beirne, Margaret; Marson, Anthony G; Weindling, A Michael

    2006-10-01

    Cardiac output is a determinant of systemic blood flow and its measurement may therefore be a useful indicator of abnormal hemodynamics and tissue oxygen delivery. The purpose of this study was to investigate in very premature newborn infants the relationships between cardiac output (left and right ventricular outputs), systemic blood pressure, peripheral blood flow (PBF) and two indicators of cerebral oxygen delivery (cerebral electrical activity and cerebral fractional oxygen extraction (CFOE)). This was a prospective observational study performed on 40 infants of less than 30 wk gestation. Digital electroencephalograms (EEGs) were recorded for one hour every day during the first four days after birth and subjected to qualitative and quantitative analysis. Left and right ventricular outputs, mean blood pressure (MBP), CFOE, PBF and arterial blood gases were measured at the same time. Within the ranges studied, there was no apparent relationship between left or right ventricular output (RVO), PBF and indicators of cerebral perfusion (cerebral electrical activity and CFOE). The EEG was normal in infants with low left and right ventricular outputs ( 30 mm Hg. Infants with low cardiac output and normal MBP seem able to maintain cerebral perfusion, possibly through vasodilatation of the cerebral microvasculature. PMID:16940235

  1. MELAS综合征患者脑灌注异常的MRI特征%MRI evaluation of cerebral perfusion changes in patients with MELAS syndrome

    Institute of Scientific and Technical Information of China (English)

    谢晟; 齐朝月; 肖江喜; 杨艳玲; 蒋学祥

    2008-01-01

    Objective To detect the changes of cerebral perfusion in patients with MELAs syndrome by using MR perfusion technique.Methods Thirteen patients with MELAS syndrome and 13 controls with normal neurological conditions were scanned with the sequence of flow-sensitive alternating inversion recovery exempting separate T1 measurement(FAIREST).Their rCBF values were obtained in regions of bilateral basilar nuclei and thalami,as well as bilateral temporal lobes and occipital lobes.Regression analysis was carried out to determine the effect of location and side on the measurement of rCBF in controls.One-way ANOVA was conducted to compare rCBF values among the control group.the lesion ROIs and normal ROIs of the MELAS syndrome group.Results The values of rCBF were 0.83±0.23,1.17±0.30.0.93±0.28,and 1.11±0.25 for the left basilar ganglia,thalamus,temporal lobe,and occipital lobe respectively,while they were 0.77±0.15,1.03±0.34,1.06±0.23,and 1.09±0.23 for the right basilar ganglia,thalamus,temporal lobe.and occipital lobe respectively.Regression analysis revealed no effect of location and side on the rCBF (P>0.05).The rCBF value for control group was 1.00±0.28,while it was 1.01±0.31 for the normal ROIs and 1.95±0.43 for the lesion ROIs in the MELAS syndrome group(F=54.99.P<0.01).The rCBF of the lesion ROIs in the MELAS syndrome group was significantly higher than the normal ROIs and the control group.Conclusion CBF maps can reveal changes of cerebral blood flow in patients with ietal MELAS,which suggests increased perfusion in the stroke-like lesions.%目的 探讨MELAS综合征患者的MR脑血流灌注异常特征.方法 对13例确诊的MELAS综合征患者和13名对照组受试者行流速敏感交替反转恢复免除独立T1测量(FAIREST)序列扫描,通过后处理生成脑血流量(CBF)图,分别测量他们的双侧基底节区、丘脑、颢叶和枕叶的相对脑血流量(rCBF)值,采用多元回归法分析对照组中测量部位和侧别对rCBF

  2. Comparison of the ocular perfusion pressure fluctuation between medically controlled and operated eyes with glaucoma

    Directory of Open Access Journals (Sweden)

    Carolina Engelbrecht

    2014-04-01

    Full Text Available Purpose: To compare the fluctuation of the OPP between eyes treated with glaucoma medication and eyes with a functioning filtering bleb. Design: cross-sectional controlled paired-eye design. Methods: Fourteen patients with POAG with one eye operated on (trabeculectomy and the fellow eye treated with medication enrolled the study. Blood pressure and intraocular pressure were measured at 7 a.m., 1 p.m., and 7 p.m. Systolic, diastolic and mean OPP were calculated for the three time points and the fluctuation (range between the highest and the lowest values compared between the eyes. Results: Mean values of the mean OPP fluctuation were 7.2 ± 3.9 mmHg and 8.5 ± 4.0 mmHg, for operated eyes and medically treated eyes, respectively (P = 0.149; mean systolic OPP fluctuation was 20.7 ± 11.2 mmHg for operated eyes and 21.2 ± 11.7 mmHg for medically treated eyes (P = 0.478; the mean diastolic OPP fluctuation was 8.4 ± 4.4 mmHg for operated eyes and 10.5 ± 5.4 mmHg for medically treated eyes (P= 0.085. Conclusion: In this small cohort of patients with POAG the mean, systolic and diastolic OPP fluctuation did not differ between the operated eyes and medically treated ones. Financial disclosure: none.

  3. 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.

  4. Contribution of perfusion pressure to vascular resistance response during head-up tilt

    Science.gov (United States)

    Imadojemu, V. A.; Lott, M. E.; Gleeson, K.; Hogeman, C. S.; Ray, C. A.; Sinoway, L. I.

    2001-01-01

    We measured brachial and femoral artery flow velocity in eight subjects and peroneal and median muscle sympathetic nerve activity (MSNA) in five subjects during tilt testing to 40 degrees. Tilt caused similar increases in MSNA in the peroneal and median nerves. Tilt caused a fall in femoral artery flow velocity, whereas no changes in flow velocity were seen in the brachial artery. Moreover, with tilt, the increase in the vascular resistance employed (blood pressure/flow velocity) was greater and more sustained in the leg than in the arm. The ratio of the percent increase in vascular resistance in leg to arm was 2.5:1. We suggest that the greater vascular resistance effects in the leg were due to an interaction between sympathetic nerve activity and the myogenic response.

  5. Ventricular Volume Load Reveals the Mechanoelastic Impact of Communicating Hydrocephalus on Dynamic Cerebral Autoregulation.

    Directory of Open Access Journals (Sweden)

    Christina Haubrich

    Full Text Available Several studies have shown that the progression of communicating hydrocephalus is associated with diminished cerebral perfusion and microangiopathy. If communicating hydrocephalus similarly alters the cerebrospinal fluid circulation and cerebral blood flow, both may be related to intracranial mechanoelastic properties as, for instance, the volume pressure compliance. Twenty-three shunted patients with communicating hydrocephalus underwent intraventricular constant-flow infusion with Hartmann's solution. The monitoring included transcranial Doppler (TCD flow velocities (FV in the middle (MCA and posterior cerebral arteries (PCA, intracranial pressure (ICP, and systemic arterial blood pressure (ABP. The analysis covered cerebral perfusion pressure (CPP, the index of pressure-volume compensatory reserve (RAP, and phase shift angles between Mayer waves (3 to 9 cpm in ABP and MCA-FV or PCA-FV. Due to intraventricular infusion, the pressure-volume reserve was exhausted (RAP 0.84+/-0.1 and ICP was increased from baseline 11.5+/-5.6 to plateau levels of 20.7+/-6.4 mmHg. The ratio dRAP/dICP distinguished patients with large 0.1+/-0.01, medium 0.05+/-0.02, and small 0.02+/-0.01 intracranial volume compliances. Both M wave phase shift angles (r = 0.64; p<0.01 and CPP (r = 0.36; p<0.05 displayed a gradual decline with decreasing dRAP/dICP gradients. This study showed that in communicating hydrocephalus, CPP and dynamic cerebral autoregulation in particular, depend on the volume-pressure compliance. The results suggested that the alteration of mechanoelastic characteristics contributes to a reduced cerebral perfusion and a loss of autonomy of cerebral blood flow regulation. Results warrant a prospective TCD follow-up to verify whether the alteration of dynamic cerebral autoregulation may indicate a progression of communicating hydrocephalus.

  6. 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

  7. Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

    Directory of Open Access Journals (Sweden)

    Peter Novak

    2016-01-01

    Full Text Available Objective. The head-up tilt test is widely used for evaluation of orthostatic intolerance. Although orthostatic symptoms usually reflect cerebral hypoperfusion, the cerebral blood flow velocity (CBFv profile in orthostatic syndromes is not well described. This study evaluated CBFv and cardiovascular patterns associated with the tilt test in common orthostatic syndromes. Methods. This retrospective study analyzed the tilt test of patients with history of orthostatic intolerance. The following signals were recorded: ECG, blood pressure, CBFv using transcranial Doppler, respiratory signals, and end tidal CO2. Results. Data from 744 patients were analyzed. Characteristic pattern associated with a particular orthostatic syndrome can be grouped into abnormalities predominantly affecting blood pressure (orthostatic hypotension, orthostatic hypertension syndrome, vasomotor oscillations, and neurally mediated syncope—cardioinhibitory, vasodepressor, and mixed, cerebral blood flow (orthostatic hypoperfusion syndrome, primary cerebral autoregulatory failure, and heart rate (tachycardia syndromes: postural tachycardia syndrome, paroxysmal sinus tachycardia, and inappropriate sinus tachycardia. Psychogenic pseudosyncope is associated with stable CBFv. Conclusions. The tilt test is useful add-on in diagnosis of several orthostatic syndromes. However diagnostic criteria for several syndromes had to be modified to allow unambiguous pattern classification. CBFv monitoring in addition to blood pressure and heart rate may increase diagnostic yield of the tilt test.

  8. Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

    Science.gov (United States)

    2016-01-01

    Objective. The head-up tilt test is widely used for evaluation of orthostatic intolerance. Although orthostatic symptoms usually reflect cerebral hypoperfusion, the cerebral blood flow velocity (CBFv) profile in orthostatic syndromes is not well described. This study evaluated CBFv and cardiovascular patterns associated with the tilt test in common orthostatic syndromes. Methods. This retrospective study analyzed the tilt test of patients with history of orthostatic intolerance. The following signals were recorded: ECG, blood pressure, CBFv using transcranial Doppler, respiratory signals, and end tidal CO2. Results. Data from 744 patients were analyzed. Characteristic pattern associated with a particular orthostatic syndrome can be grouped into abnormalities predominantly affecting blood pressure (orthostatic hypotension, orthostatic hypertension syndrome, vasomotor oscillations, and neurally mediated syncope—cardioinhibitory, vasodepressor, and mixed), cerebral blood flow (orthostatic hypoperfusion syndrome, primary cerebral autoregulatory failure), and heart rate (tachycardia syndromes: postural tachycardia syndrome, paroxysmal sinus tachycardia, and inappropriate sinus tachycardia). Psychogenic pseudosyncope is associated with stable CBFv. Conclusions. The tilt test is useful add-on in diagnosis of several orthostatic syndromes. However diagnostic criteria for several syndromes had to be modified to allow unambiguous pattern classification. CBFv monitoring in addition to blood pressure and heart rate may increase diagnostic yield of the tilt test. PMID:27525257

  9. 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)

  10. 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)

  11. 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.)

  12. 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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-15

    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 K{sub 2} 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 (MVL{sub max}) 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; MVL{sub max} and tumor grade, r = 0.559; MVL{sub max} and rCBVt, r = 0.440; MVL{sub max} 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 MVL{sub max} showed good discriminative power in distinguishing all tumor grades. rCBVt correlated strongly with tumor grade; the correlation between MVL{sub max} and tumor grade was moderate. (orig.)

  13. 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......-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...

  14. 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

  15. 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

  16. 64层CT脑灌注联合CTA在早期缺血性脑血管病中的应用%Application of perfusion and CTA by 64 slice CT in early ischemia cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    李培秀; 都日娜; 丁俊丽; 张强

    2011-01-01

    目的 探讨64层螺旋CT脑灌注加CT血管成像技术在早期脑梗死的应用价值.方法 分析总结108例发病在6h内临床可疑脑梗死,其中105例进行CT平扫、CT脑灌注和CTA,部分复查CTP的住院患者资料,并对影像资料做统计学分析.结果 CT平扫7例脑实质密度轻微减低、脑沟变浅(6.6%),CT脑灌注83例显示与临床症状对应区域血流灌注异常(79.1%),与对侧比较CBF下降、CBV下降或正常、TTP延长.22例CT灌注未见异常(20.9%).CT血管成像显示53支动脉(39例)有不同密度斑块及管腔狭窄,3例检查未成功.结论 CT脑灌注加CTA成像技术可以快速、准确确定缺血半暗带及病变血管,对早期缺血性脑血管脑的诊断和指导治疗有重要的临床应用价值.%Objective To discuss the application of cerebral perfusion and CT blood vessel imaging technique by 64-slice CT in diagnosis of cerebral infarction in its early phase. Methods To analyze and summarize the data of 108 patients who were suspected of the ischemic infarction in 6 hours. 105 among the patients were examined by CT scanning, CT perfusion and CTA. Some of those patients needed the examination by CTP again. All data were analyzed statistically. Results CT scanning showed a slight reduction in the density of brain parenchyma in 7 cases, with brain shallow groove(6. 6%) and CT perfusion showed blood perfusion abnormal corresponding to clinical symptom region in 83 cases (79. 1%). Compared with the contra-lateral, CBF were decreased and CBV were decreased or normal while TTP was extend. 22 cases of CT perfusion showed regular!20. 9%). CT blood vessel imaging showed that 53 arteries of 39 patients had spots and the pipes were narrow. 3 cases were not successful. Conclusion Cerebral perfusion and CTA imaging technique by CT can quickly and exactly definite ischemia and pathology blood vessel, which is of great clinical importance for diagnosing and curing brain ischemia in its early phase.

  17. Intensive blood pressure lowering increases cerebral blood flow in older subjects with hypertension.

    Science.gov (United States)

    Tryambake, Dinesh; He, Jiabao; Firbank, Michael J; O'Brien, John T; Blamire, Andrew M; Ford, Gary A

    2013-06-01

    Hypertension is associated with reduced cerebral blood flow (CBF). Intensive (blood pressure (BP) lowering in older people might give greater reduction in cardiovascular risk, but there are concerns that this might produce hypoperfusion which may precipitate falls and possibly stroke. We determined the effect of intensive compared with usual BP lowering on CBF in hypertensive older subjects. Individuals aged >70 years with a history of systolic hypertension on 1 or no BP lowering drugs were recruited from primary care (n=37; age, 75±4 years; systolic BP, >150 mm Hg) and randomized to receive intensive (target BP, treatment. Baseline BP (ambulatory or in clinic) and baseline gray matter CBF were not significantly different between the groups. After treatment, BP was reduced significantly in both groups but fell more in the intensive group (26/17 versus 15/5 mm Hg; Phypertension increases CBF, compared with BP lowering to usual target. These findings suggest hypertension in older people shifts the autoregulatory CBF curve rightward and downward and is reversible with BP lowering.

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

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, A. (Dept. of Neurology, Sahlgren Hospital, Goeteborg (Sweden)); Bergh, A.C. (Dept. of Clinical Physiology, Sahlgren Hospital, Goeteborg (Sweden)); Bilting, M. (Dept. of Neurosurgery, Sahlgren Hospital, Goeteborg (Sweden)); Aerlig, AA. (Dept. of Radiation Physics, Sahlgren Hospital, Goeteborg (Sweden)); Jacobsson, L. (Dept. of Radiation Physics, Sahlgren Hospital, Goeteborg (Sweden)); Stephensen, H. (Dept. of Neurosurgery, Sahlgren Hospital, Goeteborg (Sweden)); Wikkelsoe, C. (Dept. of Neurology, Sahlgren Hospital, Goeteborg (Sweden))

    1994-02-01

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

  19. In Acute Stroke, Can CT Perfusion-Derived Cerebral Blood Volume Maps Substitute for Diffusion-Weighted Imaging in Identifying the Ischemic Core?

    Directory of Open Access Journals (Sweden)

    William A Copen

    Full Text Available In the treatment of patients with suspected acute ischemic stroke, increasing evidence suggests the importance of measuring the volume of the irreversibly injured "ischemic core." The gold standard method for doing this in the clinical setting is diffusion-weighted magnetic resonance imaging (DWI, but many authors suggest that maps of regional cerebral blood volume (CBV derived from computed tomography perfusion imaging (CTP can substitute for DWI. We sought to determine whether DWI and CTP-derived CBV maps are equivalent in measuring core volume.58 patients with suspected stroke underwent CTP and DWI within 6 hours of symptom onset. We measured low-CBV lesion volumes using three methods: "objective absolute," i.e. the volume of tissue with CBV below each of six published absolute thresholds (0.9-2.5 mL/100 g, "objective relative," whose six thresholds (51%-60% were fractions of mean contralateral CBV, and "subjective," in which two radiologists (R1, R2 outlined lesions subjectively. We assessed the sensitivity and specificity of each method, threshold, and radiologist in detecting infarction, and the degree to which each over- or underestimated the DWI core volume. Additionally, in the subset of 32 patients for whom follow-up CT or MRI was available, we measured the proportion of CBV- or DWI-defined core lesions that exceeded the follow-up infarct volume, and the maximum amount by which this occurred.DWI was positive in 72% (42/58 of patients. CBV maps' sensitivity/specificity in identifying DWI-positive patients were 100%/0% for both objective methods with all thresholds, 43%/94% for R1, and 83%/44% for R2. Mean core overestimation was 156-699 mL for objective absolute thresholds, and 127-200 mL for objective relative thresholds. For R1 and R2, respectively, mean±SD subjective overestimation were -11±26 mL and -11±23 mL, but subjective volumes differed from DWI volumes by up to 117 and 124 mL in individual patients. Inter-rater agreement

  20. Voxel-based analysis of Tc-99 m ECD brain perfusion SPECT in patients with normal pressure hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Bora [Department of Neurology, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Yang, Dong-Won [Department of Neurology, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of)], E-mail: neuroman@catholic.ac.kr; Shim, Yong-Soo; Chung, Sung-Woo [Department of Neurology, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Ahn, Kook-Jin; O, Joo-Hyun; Kim, Sung-Hoon; Sohn, Hyung-Sun; Chung, Soo-Kyo [Department of Radiology, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Chung, Yong-An [Department of Radiology, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of); East-West Research Institute of Translational Medicine (EWTM), Incheon St. Mary' s Hospital, Incheon 403-720 (Korea, Republic of)], E-mail: nm@catholic.ac.kr

    2009-07-15

    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.

  1. 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

  2. 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...

  3. Assessment of Cerebral Hemodynamics by 64-Row VCT Perfusion Imaging in Patients with Moya-Moya Disease%64排VCT脑灌注成像对烟雾病的血流动力学研究

    Institute of Scientific and Technical Information of China (English)

    谢安明; 丁耀军

    2014-01-01

    Objective To investigate the changes in cerebral hemodynamics (cerebral blood flow volume,blood capacity,mean transit time and time to peak)using 64-row VCT perfusion im-aging,and to provide imaging evidence for clinical intervention.Methods Thirty patients with moya-moya disease aged 13-49 years (average age 33.8 years,14 males,16 females)were recruited in this study.Cerebral perfusion imaging was performed using a GE LightSpeed VCT scanner at a rate of 5 mL/second and a dose of 50 mL.The scan delay time was 5 seconds and scan time was 45 seconds.Post-processing was conducted with Perfusion 4 software to analyze cerebral blood flow volume,blood capacity,mean transit time and time to peak.Results Of the 30 patients,9 had is-chemic type moya-moya disease and 21 had hemorrhagic type moya-moya disease.The 64-row VCT perfusion imaging showed increased regional cerebral blood flow in 3 patients,decreased re-gional cerebral blood flow in 5,increased regional cerebral blood volume in 3,normal cerebral blood volume in 27,shortened mean transit time and time to peak in 3,and prolonged mean transit time and time to peak in 8.Conclusion Most patients with ischemic type moya-moya disease are characterized by regional hypoperfusion,while patients with hemorrhagic type moya-moya disease are characterized by normal or regional hyperperfusion.The mean transit time and time to peakare sensitive indicators of changes in cerebral hemodynamics.%目的:通过对烟雾病患者进行64排VCT脑灌注成像,了解其脑血流动力学变化情况,包括脑血流量、脑血容量、平均通过时间及达峰时间,为临床干预治疗提供影像学依据。方法30例烟雾病患者,男性14例,女性16例,年龄最大为49岁,最小为13岁,平均年龄为33.8岁。利用 GE公司生产的 LightSpeed VCT螺旋扫描机对烟雾病患者进行灌注扫描,速率5 mL·s-1、剂量50 mL、扫描延迟5 s、扫描时间45 s,然后用该公司配备的 Perfu-sion4

  4. 64 row CT cerebral perfusion applied research of brain ischemia%64排CT脑灌注对脑组织缺血程度的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘贯清; 肖新兰; 李晓; 黄小宁; 李五根

    2015-01-01

    Objective Application of 64 row CT cerebral perfusion brain tissue ischemia. Methods 40 cases of clinical diag-nosis of acute cerebral infarction,patients with unilateral lobe brain perfusion CT perfusion showed abnormal,in combination with MRI to determine infarct,according to the cerebral blood flow group,group A (low perfusion group) and group B (infarction group), respectively,evaluation of two groups of cerebral blood flow perfusion parameters and comparison analysis. Results Of 40 cases, 18 cases of group A,CTP anomaly low perfusion of figure is determined by MTT extend approximately 1.28 (R),decreased CBF mild,CBV basic no change Or moderately reduced,only determined by MTT extension was statistically significant (P<0.01);Infarc-tion group,22 cases of group B,infarction area surrounding IP abnormal perfusion is determined by MTT extend approximately 1. 48(R),CBF significantly decreased approximately 0.45(R),CBV moderately reduced,which extended determined by MTT was sta-tistically significant (P<0.001),decrease CBF was statistically significant (P<0.01);Infarction district performance is determined by MTT extend approximately 1.64(R),CBF significantly decreased approximately 0.36(R),significantly lower CBV (approximately 0. 37)R. Which determined by MTT extension was statistically significant (P<0.001),CBF decline was statistically significant(P<0.01). Conclusion Brain tissue hypoperfusion area with the infarction in central and peripheral IP area the perfusion parameters have significant differences,according to the variation of perfusion parameters characteristics can make the image on the degree of is-chemic infarction assessment,when rCBF<0.5,suggesting infarction risk is extremely high,the clinical guidance for early interven-tion treatment.%目的:探讨应用64排CT脑灌注评价脑组织缺血程度。方法40例临床诊断急性脑梗塞,CT灌注显示单侧脑叶灌注异常患者,结合MRI判断梗塞,根据脑血流量进行分组,A

  5. 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.

  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. Diagnostic Value of Brain Perfusion Imaging with 64 Multi-Detector Spiral CT in Early Cerebral Infarction%64排螺旋 CT 脑灌注成像对早期脑梗死的诊断价值

    Institute of Scientific and Technical Information of China (English)

    奚彬; 盛伟华; 唐建伟; 黄松; 宋黎涛

    2014-01-01

    目的:探讨64排螺旋 CT 脑灌注成像(CT perfusion imaging,CTP)对早期脑梗死的诊断价值。方法:临床拟诊早期脑梗死患者38例,均在症状出现24 h 内行头颅 CT 平扫及 CTP 检查。将脑梗死核心区、缺血半暗带(ischemic penumbra,IP)区与健侧对应区的情况做对比分析。结果:38例患者中,15例头颅 CT 平扫发现可疑脑梗死区,主要位于大脑半球,表现为密度轻度减低、局部脑沟稍变浅等;其余23例患者 CT 平扫未发现异常。38例患者的 CTP 检查均发现灌注异常区,表现为脑梗死区脑血流量(cerebral blood flow,CBF)与脑血容量(cerebral blood volume,CBV)均较健侧对应区明显下降,对比剂平均通过时间(mean transit time,MTT)较健侧对应区缩短,对比剂达峰时间(time to peak,TTP)较健侧对应区明显延长,差异均有统计学意义(P <0.01)。早期脑梗死患者 IP 区与梗死核心区比较,CBF、CBV、MTT 及 TTP 差异均有统计学意义(P <0.01);IP区与健侧对应区比较,CBF、MTT、TTP 差异均有统计学意义(P <0.05、0.01),CBV 差异无统计学意义(P >0.05)。获得随访的18例患者中,经积极溶栓等治疗后梗死区缩小6例,梗死区消失5例,仅表现为梗死区 TTP 和 MTT 延长、CBF 和 CBV 变化不大3例,梗死区无明显变化4例。结论:64排螺旋 CTP 检查可以准确地提示早期脑梗死。%Objective:To explore the diagnostic value of CT perfusion imaging(CTP)with 64 multi-detector spiral CT in early cerebral infarction.Methods:A total of 38 patients with suspected early cerebral infarction underwent plain CT and CTP within 24 h after the onset of related symptoms.The imaging results in infarction core area,ischemic penumbra (IP) and the contralateral normal region were comparatively analyzed.Results:Early cerebral infarction,mainly in cerebral hemispheres, were suspected

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-15

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

  9. 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 ...

  10. Study on the correlation between clinical aphasia and cerebral blood perfusion after acute cerebral infarction%急性脑梗死后失语症与脑血流灌注的相关性探讨

    Institute of Scientific and Technical Information of China (English)

    胡军; 朱文炳; 谢瑞满; 修雁

    2002-01-01

    Objective The SPECT brain perfusion was performed to explore the correlation between the yielded image data and the clinical characteristics of aphasia.Method The language function assessment of WAB and SPECT blood perfusion imaging were applied to 21 aphasia patients with dominant ischemic stroke.The correlations between the aphasic characteristics and the ROI rCBF of language regions were analyzed.Result The significant correlations were found between the different brain regions and the different language function deficits,and the correlation between temporal lobe and language function deficits was even higher.Conclusion SPECT brain perfusion imaging can show function disorder of language and aphasia probably caused by the destruction of language nervous network.

  11. 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)....

  12. 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...... 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...

  13. Aortic arch replacement with a beating heart: a simple method using continuous 3-way perfusion.

    Science.gov (United States)

    Abu-Omar, Y; Ali, J M; Colah, S; Dunning, J J

    2014-01-01

    We describe a simplified 3-way perfusion strategy that could be used in complex aortic procedures, which ensures continuous end-organ perfusion and minimizes the potential risks of cardiac, cerebral and peripheral ischaemic complications.

  14. 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)

  15. 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

  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. 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

  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. Cerebral hemodynamics in normal-pressure hydrocephalus. Evaluation by 133Xe inhalation method and dynamic CT study

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, N.; Kusunoki, T.; Wakabayashi, T.; Matsumoto, S.

    1984-09-01

    Cerebral hemodynamics in 31 patients with suspected normal-pressure hydrocephalus were studied by means of the xenon-133 (133Xe) inhalation method and on dynamic computerized tomography (CT) scanning. Cerebral blood flow (CBF) is reduced in all patients with dementia. Hypoperfusion was noted in a frontal distribution in these patients compared with normal individuals. There was no difference in CBF patterns between patients with good and those with poor outcome. The CBF was increased following cerebrospinal fluid (CSF) shunting in patients who responded to that procedure: increase in flow correlated with clinical improvement, frontal and temporal lobe CBF was most markedly increased, and the CBF pattern became normal. In contrast, CBF was decreased after shunt placement in patients who were considered to have suffered from degenerative dementia, as evidenced by non-response to shunting. Dynamic computerized tomography studies demonstrated that patients with a good outcome showed a postoperative reduction in mean transit time of contrast material, most prominent in the frontal and temporal gray matter, and slight in the deep frontal structures, but not in the major cerebral vessels. Patients with poor outcome after shunting, however, had an increase in transit time in all regions. This corresponded well with the results as determined by the 133Xe inhalation method.

  20. 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)...

  1. 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

    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 ....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....

  2. 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

  3. 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

  4. 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

    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......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...

  5. 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...

  6. Pseudo-asymmetry of cerebral blood flow in arterial spin labeling caused by unilateral fetal-type circle of Willis: Technical limitation or a way to better understanding physiological variations of cerebral perfusion and improving arterial spin labeling acquisition?

    Science.gov (United States)

    Law-Ye, B; Geerts, B; Galanaud, D; Dormont, D; Pyatigorskaya, N

    2016-09-01

    In the recently published article, "Unilateral fetal-type circle of Willis anatomy causes right-left asymmetry in cerebral blood flow with pseudo-continuous arterial spin labeling: A limitation of arterial spin labeling-based cerebral blood flow measurements?", it was shown by the method of arterial spin labeling (ASL) that unilateral fetal-type circle of Willis could induce variation of blood flow in cerebellar and posterior cerebral artery territory. We believe that the reported observation, rather than being a limitation, gives several interesting cues for understanding the ASL sequence. In this commentary, we formulate some suggestions regarding the use of ASL in clinical practice, discuss the potential causes of the above-mentioned pseudo-asymmetry and consider future improvements of the ASL technique.

  7. 急性脑梗死320排 CT 脑灌注成像分析%The analysis of whole-brain CT perfusion imaging with 320-detector row CT in acute cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    阮志兵; 段庆红

    2014-01-01

    Objective To explore the clinical value of whole-brain CT perfusion imaging with 320-detector row CT in early acute cerebral infarction.Methods The CTP parameters(CBF,CBV,MTT,TTP)and its pseudo color map of 25 patients with early acute cerebral infarction were retrospectively analysed and compared between infarction area,ischemic penumbra (IP)and the con-tralateral normal region.Results The abnormal perfusion area were found on CTP in 25 patients with early acute cerebral infarction. CTP showed cerebral blood flow (CBF)and cerebral blood volume (CBV)decreased significantly,mean transit time (MTT)short-ened significantly,time to peak (TTP)was significantly longer than those of the contralateral normal region in 7 cases of acute cere-bral infarct core.18 cases of IP lesions showed CBF decreased slightly,CBV increased slightly or maintain normal,MTT and TTP extension compared with contralateral.CBF,CBV,MTT,TTP values had significantly differences between infarct region and the contralateral corresponding normal region,between the infarct core area and IP of acute cerebral infarction (P 0.05)between IP region and the contralateral corresponding normal region,but showed a downward trend in blood flow.Parameter color maps of CTP could di-rectly,clearly and sensitively show abnormal changes region about cerebral blood flow.In particular,MTT and TTP maps shows ab-normal region clearer and sensitively.Follow-up 18 cases of IP,active lesions deduced in 6 cases,the lesions disappeared in 5 pa-tients (CT/ MRI showed no abnormal,and the clinical symptoms disappeared)after thrombolytic therapy,7 cases of MRI and CT scans confirmed infarction stove.Conclusion Whole-brain CTP with 320-detector row CT can early show the acute cerebral infarc-tion and its ischemic penumbra,it has significant important clinical value for early acute cerebral infarction.%目的:探讨320排 CT 全脑灌注成像(CTP)在早期急性脑梗死中的临床应用价值。方法回顾性分析25

  8. 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...

  9. 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...... 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...... identified best by CTH (AUC=0.763; pflow control in tumor growth by demonstrating...

  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. CT脑灌注成像临床诊断急性脑梗死价值评价与平扫CT值差值的测量价值%Value Evaluation on Clinical Diagnosis of CT Cerebral Perfusion Imaging on Acute Cerebral infarction and Measurement Value of Difference Value of Plain Scan CT Value

    Institute of Scientific and Technical Information of China (English)

    余东

    2015-01-01

    Objective This Paper is to explore the application value of CT perfusion imaging and differential value of measured CT value in the diagnosis of acute cerebral infarction. Methods Thirty six patients with acute cerebral infarction admitted the Radiology Department of the Hospital were selected as research subjects, retrospective analysis and summary were conducted according to clinical data. CT plaint scan and brain CT perfusion imaging were made respectively, The time to peak (TIP), cerebral blood flow (CBF) and cerebral blood volume (CBV) of CT perfusion imaging were evaluated, the difference of CT value on both sides of symmetric positions was measured. In addition, 36 patients with no brain disease and normal nervous function were divided into the control group, and diagnostic value of the difference between CT perfusion imaging and CT measurement value in acute cerebral infarction was analyzed. Results It is visually found that there were 17 patients with suspicious lesions with the sensitivity at 47.2%, and it was found that there were 28 patients with suspicious lesions by measuring CT value difference. It was found that the CTP of 3 patients was normal CT perfusion imaging examination, and such 2 patients were finally diagnosed to suffer from transient ischemic attack, and others were abnomal, rCBF, rCBV and rTTP changed obviously, the comparison in lesion center and perimeter and controlled side satisfied p<0.05, and the differences were statistically significant. Conclusion CT perfusion imaging and the difference value in CT value measurement delivers high application value in the diagnosis of acute cerebral infarction, and it is capable of diagnosing cerebral infarction in early differential diagnosis, the infarct area and ischemic penumbra area may be differentiated via through quantitative analysis, providing important basis for clinical determination on the existence of infarct and development of therapeutic schedule.%目的:探讨CT灌注成像

  12. 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

  13. 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

  14. [The response of cerebral blood flow and systemic arterial blood pressure to hypercapnia and hypocapnia in humans].

    Science.gov (United States)

    Kulikov, V P; Kuznetsova, D V

    2013-01-01

    In 11 healthy volunteers 21 +/- 3.7 years old was monitored cerebral blood flow (CBF) by transcranial Doppler (TCD) of middle cerebral artery and mean hemodynamic arterial blood pressure (MAP) by continuous non-invasive measurement "beat-to-beat" at normocapnia, hypercapnia and hypocapnia. Hypercapnia was creating by rebreathing, hypocapnia was creating by spontaneous hyperventilation. The partial pressure of CO2 in alveolar air (PetCO2) was monitored by capnograph, embedded in the TCD-analyzer. During hypercapnia the velocity of CBF and PetCO2 were significantly increased already at 10 s, which was considerably earlier than the increase in the MAP (30 s). During hypocapnia velocity CBF and PetCO2 were significantly decreased at 10 s, and MAP was not changed. We have installed the threshold PetCO2 42 (41; 44) mm Hg, below which amplification CBF occurs at a constant MAP and reflects the true cerebrovascular reactivity to CO2. PMID:23805713

  15. Brain edema formation correlates with perfusion deficit during the first six hours after experimental subarachnoid hemorrhage in rats

    Directory of Open Access Journals (Sweden)

    Westermaier Thomas

    2012-07-01

    Full Text Available Abstract Background Severe brain edema is observed in a number of patients suffering from subarachnoid hemorrhage (SAH. Little is known about its pathogenesis and time-course in the first hours after SAH. This study was performed to investigate the development of brain edema and its correlation with brain perfusion after experimental SAH. Methods Male Sprague–Dawley rats, randomly assigned to one of six groups (n = 8, were subjected to SAH using the endovascular filament model or underwent a sham operation. Animals were sacrificed 15, 30, 60, 180 or 360 minutes after SAH. Intracranial pressure (ICP, mean arterial blood pressure (MABP, cerebral perfusion pressure (CPP and bilateral local cerebral blood flow (LCBF were continuously measured. Brain water content (BWC was determined by the wet/dry-weight method. Results After SAH, CPP and LCBF rapidly decreased. The decline of LCBF markedly exceeded the decline of CPP and persisted until the end of the observation period. BWC continuously increased. A significant correlation was observed between the BWC and the extent of the perfusion deficit in animals sacrificed after 180 and 360 minutes. Conclusions The significant correlation with the perfusion deficit after SAH suggests that the development of brain edema is related to the extent of ischemia and acute vasoconstriction in the first hours after SAH.

  16. 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.)

  17. 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.

  18. Comparison of cerebral perfusion reserve and collateral circulation in patients with internal carotid artery disease; Die zerebrale Perfusionsreserve in Abhaengigkeit vom Kollateralisierungstyp bei Patienten mit A.-carotis-interna-Stenosen/-Verschluessen

    Energy Technology Data Exchange (ETDEWEB)

    Reiche, W.; Schaefer, R.; Hermes, M. [Abt. fuer Neuroradiologie, Radiologische Klinik der Universitaet des Saarlandes, Homburg/Saar (Germany); Mueller, M. [Neurologische Klinik der Universitaet des Saarlandes, Homburg/Saar (Germany)

    1997-11-01

    The cerebral hemodynamics in patients with carotid disease is influenced by a network of extra- and intracranial collaterals. The purpose of this study was to compare the findings of regional cerebral perfusion reserve (rCPR) with angiographically proven collateral circulation. In 41 patients (28 men, 13 women, age 63{+-}10 years) with angiographically proven carotid stenoses or occlusions (30 stenoses, 11 occlusions) 24 {sup 99m}Tc-HMPAO-SPECT and 25 dynamic Xe-CT investigations were conducted, both before and after acetazolamide stimulation. rCPR was quantified as the ratio (1) of the absolute rCBF values obtained by Xe-CT and (2) of the count density measured by HMPAO-SPECT of the acetazolamide administration. A rCPR of less than 95% in a vascular territory was classified as compromised rCPR. A recent CT examination was available in all cases. According to the angiographic findings the patients could be classified into (1) group A (n=9) with residual carotid perfusion, (2) Group B (n=8) with collateralization via the circle of Willis, and (3) group C (n=24) with leptomeningeal or opthalmic artery collateral circulation. (orig./AJ) [Deutsch] Die zerebrale Haemodynamik bei A.-carotis-interna-(ACI-)Stenosen/-Verschluessen wird von extra- und intrakaniellen Kollateralen beeinflusst. Ziel dieser Studie war es, die Befunde der regionalen zerebralen Perfusionsreserve (rCPR) mit angiographisch nachgewiesenen Kollateralisierungs- und Anastomosierungstypen zu vergleichen. Bei 41 Patienten (28 Maennder, 13 Frauen, Alter 63{+-}10 Jahre) mit angiographisch untersuchten ACl-Stenosen/-Verschluessen (30 Stenosen, 11 Verschluesse) wurden in 24 Faellen eine {sup 99m}Tc-HMPAO-SPECT und in 25 eine dynamische Xe-CT jeweils vor und nach Diamox{sup R}-Stimulation durchgefuehrt. Fuer die rCPR-Quantifizierung wurde in der Xe-CT das Verhaeltnis der absoluten rCBF-Werte und in der HMPAO-SPECT der Zaehlratendichten jeweils nach zu vor Diamox berechnet. Eine rCPR<95% in einem zerebralen

  19. 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

  20. Time-varying modeling of cerebral hemodynamics.

    Science.gov (United States)

    Marmarelis, Vasilis Z; Shin, Dae C; Orme, Melissa; Rong Zhang

    2014-03-01

    The scientific and clinical importance of cerebral hemodynamics has generated considerable interest in their quantitative understanding via computational modeling. In particular, two aspects of cerebral hemodynamics, cerebral flow autoregulation (CFA) and CO2 vasomotor reactivity (CVR), have attracted much attention because they are implicated in many important clinical conditions and pathologies (orthostatic intolerance, syncope, hypertension, stroke, vascular dementia, mild cognitive impairment, Alzheimer's disease, and other neurodegenerative diseases with cerebrovascular components). Both CFA and CVR are dynamic physiological processes by which cerebral blood flow is regulated in response to fluctuations in cerebral perfusion pressure and blood CO2 tension. Several modeling studies to date have analyzed beat-to-beat hemodynamic data in order to advance our quantitative understanding of CFA-CVR dynamics. A confounding factor in these studies is the fact that the dynamics of the CFA-CVR processes appear to vary with time (i.e., changes in cerebrovascular characteristics) due to neural, endocrine, and metabolic effects. This paper seeks to address this issue by tracking the changes in linear time-invariant models obtained from short successive segments of data from ten healthy human subjects. The results suggest that systemic variations exist but have stationary statistics and, therefore, the use of time-invariant modeling yields "time-averaged models" of physiological and clinical utility.

  1. 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...

  2. 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

  3. 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.

  4. Perfusion harmonic imaging of the human brain

    Science.gov (United States)

    Metzler, Volker H.; Seidel, Guenter; Wiesmann, Martin; Meyer, Karsten; Aach, Til

    2003-05-01

    The fast visualisation of cerebral microcirculation supports diagnosis of acute cerebrovascular diseases. However, the commonly used CT/MRI-based methods are time consuming and, moreover, costly. Therefore we propose an alternative approach to brain perfusion imaging by means of ultrasonography. In spite of the low signal/noise-ratio of transcranial ultrasound and the high impedance of the skull, flow images of cerebral blood flow can be derived by capturing the kinetics of appropriate contrast agents by harmonic ultrasound image sequences. In this paper we propose three different methods for human brain perfusion imaging, each of which yielding flow images indicating the status of the patient's cerebral microcirculation by visualising local flow parameters. Bolus harmonic imaging (BHI) displays the flow kinetics of bolus injections, while replenishment (RHI) and diminution harmonic imaging (DHI) compute flow characteristics from contrast agent continuous infusions. RHI measures the contrast agents kinetics in the influx phase and DHI displays the diminution kinetics of the contrast agent acquired from the decay phase. In clinical studies, BHI- and RHI-parameter images were found to represent comprehensive and reproducible distributions of physiological cerebral blood flow. For DHI it is shown, that bubble destruction and hence perfusion phenomena principally can be displayed. Generally, perfusion harmonic imaging enables reliable and fast bedside imaging of human brain perfusion. Due to its cost efficiency it complements cerebrovascular diagnostics by established CT/MRI-based methods.

  5. Renal perfusion scintiscan

    Science.gov (United States)

    Renal perfusion scintigraphy; Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion ... supply the kidneys. This is a condition called renal artery stenosis. Significant renal artery stenosis may be ...

  6. Cerebral hemodynamics and functional prognosis in hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Osamu; Nishikawa, Michio; Watanabe, Shu; Yamakawa, Hiroyasu; Kinoshita, Yoshimasa; Uno, Akira; Handa, Hajime (Hamamatsu Rosai Hospital, Shizuoka (Japan))

    1989-11-01

    The functional outcome of cerebral hemodynamics in the chronic stage of juvenile hydrocephalus was determined using single photon emission computed tomography (SPECT). Five patients including three with aqueductal stenosis, one with post-meningitic hydrocephalus, and one case with hydrocephalus having developed after repair of a huge occipital encephalocele. Early images of cerebral blood flow (CBF) were obtained 25 minutes after intravenous injection of 123-I-iodoamphetamine (IMP), and late images were scanned 3 hours later. Cerebral blood volume (CBV) was also measured using {sup 99m}Tc in three patients. Twenty cases with adult communicating hydrocephalus were also investigated from the point of view of shunt effectiveness. Although there was no remarkable change in the cerebrovascular bed in the juvenile cases, CBF of the remnant brain parenchyma was good irrespective of the degree of ventricular dilatation. There was a periventricular-related IMP uptake in each case; however, it somehow matched the ventricular span. Functional outcome one to 23 years after the initial shunt operation was good in every case, despite multiple shunt revisions. Redistribution on late images had no bearing on clinical states. In adult cases, 8 patients with effective shunting demonstrated a relatively localized periventricular low perfusion, with preoperative increased cerebrospinal fluid (CSF) pressure. On the contrary, 12 patients with no improvement with or without ventricular-reduced IMP uptake, despite low CSF pressure. The present study indicates that periventricular hemodynamics may play an important role in cerebral function compromised by hydrocephalus. (J.P.N.).

  7. 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

  8. 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.

  9. 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)

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    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 ....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 MCA V......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...

  11. CT Perfusion ASPECTS in the Evaluation of Acute Ischemic Stroke: Thrombolytic Therapy Perspective

    Directory of Open Access Journals (Sweden)

    Niko Sillanpaa

    2011-02-01

    Full Text Available 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 ASPECTS in the detection of reversible ischemia was analyzed. Materials and Methods: We retrospectively reviewed the clinical and imaging data of 92 consecutive patients who received intravenous thrombolytic therapy for acute (duration Results: A perfusion defect could be detected in 50% of the patients. ASPECTS correlated inversely with the clinical outcome in the following order: follow-up NCCT > cerebral blood volume (CBV > mean transit time (MTT > admission NCCT. The follow-up NCCT and the CBV displayed a statistically significant difference from the admission NCCT, while the MTT did not reach statistical significance. The threshold that best differentiated between good and bad clinical outcome on admission was CBV ASPECTS ≧7. In patients with CT perfusion ASPECTS mismatch, MTT and CBV ASPECTS essentially provided the lower and upper limits for the follow-up NCCT ASPECTS, thus defining the spectrum of possible outcomes. Furthermore, CT perfusion ASPECTS mismatch strongly correlated (r = 0.83 with the mismatch between the tissue at risk and the final infarct, i.e. the amount of salvaged tissue. This finding suggests that the CT perfusion ASPECTS mismatch adequately identifies the amount of potentially salvageable ischemic brain tissue. Conclusions: Parameters derived from the use of CT perfusion ASPECTS can detect reversible ischemia and are correlated with clinical outcome.

  12. CT脑灌注成像在短暂性脑缺血发作的应用价值探讨%To Study the Application Value of CT Cerebral Perfusion Imaging in Transient Ischemic Attack

    Institute of Scientific and Technical Information of China (English)

    杜彦挺; 夏志强; 杜光勇; 张伟; 李涛

    2016-01-01

    目的:探讨CT脑灌注成像(CT perfusion,CTP)在短暂性脑缺血发作(transient ischemic attack,TIA)的应用价值。方法收集我院从2013年4月至2015年4月收治的55例短暂性TIA患者作为研究对象,发病24h内进行CTP和CTA(CT angiography)检查,发病72h内进行头颅MRI(magnetic resonance imaging)和MRA(magnetic resonance angiography)进行检查,比较CTP与其他检查方法的检出结果差异,并对病灶侧与健康侧的脑灌注成像参数如获得达峰时间(time to peak, TTP)、平均通过时间(mean transit time, MTT)、脑血流量(cerebral blood flow, CBF)、脑血容量(cerebral blood volume, CBV)进行比较分析。结果 CTA检出35个病灶,MRI检出44个病灶,CTP检出59个病灶,CTP对病灶的检出率高于CTA和MR检查,具有统计学意义(P<0.05);CTP检出的病灶表现分型中I1期12个,I2期29个,II1期11个, II2期7个,I2期明显多于其他分型,具有统计学意义(P<0.05);CTP病灶侧的TTP值、MTT值(P<0.05);CTP病灶侧的CBV值与健康侧没有明显差异(P>0.05)。结论采用CT脑灌注成像检查短暂性脑缺血发作可以全面的诊断,对治疗短暂性脑缺血发作提供可靠的依据。%Objective To study the application value of CT cerebral perfusion imaging(CTP) in Transient ischemic attack(TIA).Methods Fifty-five cases of transient ischemic attack from April 2013 to April 2015 in our hospital were collected as research subject, all of them were performed CTP, CTA(CT angiography) in 24 hours after onset and MRI(Magnetic Resonance imaging) and MRA(Magnetic Resonance angiography) in 72 hours. The inspection results of CTA and MRI and CTP were compared, and the parameters of CTP like time to peak(TTP), mean transit time(MTT), cerebral blood flow(CBF), cerebral blood volume(CBV) were analyzed and compared between lesion side and healthy side.Results Thirty-five lesions were checked out by CTA inspection, 44 lesions by MRI, and 59

  13. Beneficial effect of epinephrine infusion on cerebral and myocardial blood flows during CPR.

    Science.gov (United States)

    Koehler, R C; Michael, J R; Guerci, A D; Chandra, N; Schleien, C L; Dean, J M; Rogers, M C; Weisfeldt, M L; Traystman, R J

    1985-08-01

    It is hypothesized that epinephrine improves the ability to resuscitate the heart through a mechanism thought to be related to the increase in aortic pressure. Our results with epinephrine infusion during CPR are consistent with this hypothesis. Epinephrine selectively increased vascular resistance in noncerebral, noncoronary vascular beds, as indicated by a decrease in microsphere-determined blood flow in these areas. This increased vascular resistance raised aortic pressure during the chest compression phase and the relaxation phase of CPR. Because intracranial and right atrial pressures were only slightly higher with epinephrine, cerebral and myocardial perfusion pressures and blood flows were significantly improved. This beneficial effect (compared to no administration of a vasopressor) was more pronounced as CPR progressed beyond ten minutes. Enhanced cerebral and myocardial perfusion occurred with epinephrine when either the conventional or simultaneous compression and ventilation (SCV) mode of CPR was employed in dogs. Similar selective perfusion was sustained for 50 minutes of SCV-CPR with epinephrine, even when the onset of CPR was delayed five minutes. Regional brain blood flow differed in the delayed-CPR group in that cerebellum, brain stem, and thalamic regions initially had higher blood flows. In an infant animal model of CPR using conventional CPR in piglets, epinephrine also was found to increase cerebral and myocardial blood flows. These results show that administration of epinephrine benefits different age groups of different species with different modes of CPR; that benefits occur even with delayed onset of CPR which is associated with additional anoxia and acidosis; and that epinephrine administration is particularly effective in sustaining cerebral and coronary perfusion during prolonged CPR.

  14. 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...

  15. 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)

  16. 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.

  17. 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...

  18. Is cerebral oxygenation negatively affected by infusion of norepinephrine in healthy subjects?

    DEFF Research Database (Denmark)

    Brassard, P.; Seifert, T.; Secher, Niels H.

    2009-01-01

    BACKGROUND: Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral oxygenation is not clear. The aim of this study was to evaluate the impact of the infusion of norep......BACKGROUND: Vasopressor agents are commonly used to increase mean arterial pressure (MAP) in order to secure a pressure gradient to perfuse vital organs. The influence of norepinephrine on cerebral oxygenation is not clear. The aim of this study was to evaluate the impact of the infusion...... of norepinephrine on cerebral oxygenation in healthy subjects. METHODS: Three doses of norepinephrine (0.05, 0.1, and 0.15 microg kg(-1) min(-1) for 20 min each) were infused in nine healthy subjects [six males; 26 (6) yr, mean (SD)]. MAP, cerebral oxygenation characterized by frontal lobe oxygenation (Sc(O2...... infused at 0.1 microg kg(-1) min(-1) [Sc(O2): 78 (75-94) to 69 (61-83)%; P

  19. Cerebral glutamine concentration and lactate-pyruvate ratio in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, P.N.; Hauerberg, J.; Frederiksen, Hans-Jørgen;

    2008-01-01

    AIM: Hyperammonemia causes brain edema and high intracranial pressure (ICP) in acute liver failure (ALF) by accumulation of glutamine in brain. Since a high-level glutamine may compromise mitochondrial function, the aim of this study was to determine if the lactate-pyruvate ratio is associated...... with a rise in the glutamine concentration and ICP. PATIENTS AND METHODS: In 13 patients with ALF (8F/5M; median age 46 (range 18-66) years) the cerebral extracellular concentrations of glutamine, lactate, and pyruvate were measured by in vivo brain microdialysis together with ICP and cerebral perfusion......-pyruvate ratio (r = 0.89, P rise in lactate...

  20. 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.

  1. An Experimental Model of Vasovagal Syncope Induces Cerebral Hypoperfusion and Fainting-Like Behavior in Awake Rats

    Science.gov (United States)

    McBride, Devin W.; Reis, Cesar; Frank, Ethan; Klebe, Damon W.; Zhang, John H.; Applegate, Richard

    2016-01-01

    Vasovagal syncope, a contributing factor to elderly falls, is the transient loss of consciousness caused by decreased cerebral perfusion. Vasovagal syncope is characterized by hypotension, bradycardia, and reduced cerebral blood flow, resulting in fatigue, altered coordination, and fainting. The purpose of this study is to develop an animal model which is similar to human vasovagal syncope and establish an awake animal model of vasovagal syncope. Male Sprague-Dawley rats were subjected to sinusoidal galvanic vestibular stimulation (sGVS). Blood pressure, heart rate, and cerebral blood flow were monitored before, during, and post-stimulation. sGVS resulted in hypotension, bradycardia, and decreased cerebral blood flow. One cohort of animals was subjected to sGVS while freely moving. sGVS in awake animals produced vasovagal syncope-like symptoms, including fatigue and uncoordinated movements; two animals experienced spontaneous falling. Another cohort of animals was preconditioned with isoflurane for several days before being subjected to sGVS. Isoflurane preconditioning before sGVS did not prevent sGVS-induced hypotension or bradycardia, yet isoflurane preconditioning attenuated sGVS-induced cerebral blood flow reduction. The sGVS rat model mimics elements of human vasovagal syncope pathophysiology (hypotension, bradycardia, and decreased cerebral perfusion), including behavioral symptoms such as fatigue and altered balance. This study indicates that the sGVS rat model is similar to human vasovagal syncope and that therapies directed at preventing cerebral hypoperfusion may decrease syncopal episodes and reduce injuries from syncopal falls. PMID:27658057

  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. 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.

  4. 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

  5. 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.)

  6. Photoacoustic & pulsed laser-doppler monitoring of blood concentration and perfusion in tissue

    OpenAIRE

    Kolkman, Roy Gerardus Maria

    2002-01-01

    In medicine there are situations that require continuous bedside monitoring of perfusion and blood volume. Such a situation can occur when children are born prematurely. Those children have a high risk to develop a handicap, which is most likely caused by cerebral damage due to impaired brain perfusion. Monitoring cerebral perfusion can provide information for preventive treatment. In this thesis we have explored the potential of photoacoustics and laser Doppler flowmetry for measurement of c...

  7. Evaluation of stenosis degree of the middle cerebral artery with high-resolution MRI and brian blood supply with MR perfusion weighted imaging%高分辨率MRI评价大脑中动脉狭窄程度与灌注加权成像评估脑供血的研究

    Institute of Scientific and Technical Information of China (English)

    崔恒; 程敬亮; 张勇

    2012-01-01

    Objective To study the value of high-resolution MRI(HRMRI) and MR perfusion weighted imaging(PWI) in evaluating the middle cerebral artery (MCA) stenosis degree and the brian blood supply. Methods PWI was performed in 30 patients with unilateral stenosis of MCA was diagnosed by HRMRI. The cerebral perfusion parameters including regional cerebral blood volume (rCBV) .regional cerebral blood flow(rCBF) .regional mean transit time(rMTT) and regional time to peak(rTTP) of the both cerebral hemispheres were quantitatively analysed. Results Among 30 patients, the MCA stenosis diagnosed by HRMRI as mild in 7, moderate in 9 and severe or acclusion in 14,respectively. Abnormal perfusion presented in all cases. The perfusion parameters (rCBF, rMTT and rTTP) had statistical significance. Between the rate of MCA moderate stenosis, severe stenosis or occlusion and the increase rate of rMTT showed a positive correlation(r=0. 897 and 0. 829 respectively,P<0. 01). Conclusion There is significantly value in evaluation of the MCA stenosis degree by HRMRI, which in combination with PWI to assess brain blood supply is of important value for clinic.%目的 探讨高分辨率MRI(high-resolution MRI,HRMRI)判定大脑中动脉(middle cerebral artery,MCA)狭窄程度与脑MRI灌注加权成像(perfusion weighted imaging,PWI)评价脑供血的价值.方法 对30例短暂性脑缺血(TIA)患者行HRMRI以判定单侧MCA狭窄程度,并行MRI PWI检查,得出患侧和镜像侧灌注参数,包括相对脑血容量(relative cerebral blood volume,rCBV)、相对脑血流量(relative cerebral blood flow,rBCF)、相对平均通过时间(relative mean transit time,rMTT)、相对达峰时间(relative time to peak,rTTP),并对其进行定量分析.结果 30例患者中,HRMRI判定MCA轻度狭窄7例,中度狭窄9例,重度狭窄或闭塞14例;30例灌注均出现异常,rCBF、rMTT、rTTP灌注参数均具有统计学意义,其中MCA中度、重度狭窄或闭塞组狭窄率与r

  8. 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.)

  9. 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.)

  10. Cerebral Autoregulation in Normal Pregnancy and Preeclampsia

    NARCIS (Netherlands)

    van Veen, Teelkien R.; Panerai, Ronney B.; Haeri, Sina; Griffioen, Annemiek C.; Zeeman, Gerda; Belfort, Michael A.

    2013-01-01

    OBJECTIVE: To test the hypothesis that preeclampsia is associated with impaired dynamic cerebral autoregulation. METHODS: In a prospective cohort analysis, cerebral blood flow velocity of the middle cerebral artery (determined by transcranial Doppler), blood pressure (determined by noninvasive arter

  11. 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

  12. 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