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Sample records for brain spet perfusion

  1. [Effects of treatment with OKT3 on brain perfusion in a heart transplant patient with SPET with 99mTc-HMPAO].

    PubMed

    Quirce, R; Carril, J; Vallina, N; Montero, A; Uriarte, I

    1999-10-01

    A heart transplant patient treated with OKT3 developed a severe headache which worsened and was accompanied by a sudden decrease in the patient's consciousness level and aphasia when the treatment course was completed. CT was performed and was normal. SPET imaging with 99mTc-HMPAO of cerebral blood flow done 16 hours later revealed multiple and clear focal defects in the blood flow. Analysis of cerebral spinal fluid revealed aseptic pleocytosis. Five days after the completion of treatment, the symptoms remitted and a new control SPET 3 weeks later was completely normal. A diagnosis of neurotoxicity secondary to OKT3 administration was established. PMID:10562666

  2. What is the benefit of CT-based attenuation correction in myocardial perfusion SPET?

    PubMed

    Apostolopoulos, Dimitrios J; Savvopoulos, Christos

    2016-01-01

    In multimodality imaging, CT-derived transmission maps are used for attenuation correction (AC) of SPET or PET data. Regarding SPET myocardial perfusion imaging (MPI), however, the bene����t of CT-based AC (CT-AC) has been questioned. Although most attenuation-related artifacts are removed by this technique, new false defects may appear while some true perfusion abnormalities may be masked. The merits and the drawbacks of CT-AC in MPI SPET are reviewed and discussed in this editorial. In conclusion, CT-AC is most helpful in men, overweight in particular, and in those with low or low to intermediate pre-test probability of coronary artery disease (CAD). It is also useful for the evaluation of myocardial viability. In high-risk patients though, CT-AC may underestimate the presence or the extent of CAD. In any case, corrected and non-corrected images should be viewed side-by-side and both considered in the interpretation of the study. PMID:27331200

  3. The prevalence of a false-positive myocardial perfusion stress SPET test in a skinny patient, induced by projection truncation.

    PubMed

    Tsougos, Ioannis; Alexiou, Sotiria; Theodorou, Kiki; Valotassiou, Varvara; Georgoulias, Panagiotis

    2015-01-01

    During the last decade, technical developments in myocardial perfusion single photon emission tomography (SPET) imaging systems have significantly improved the accuracy of diagnosing coronary artery disease. Nevertheless, the patient's position and/or the acquisition protocol can affect the studies' quality, possibly leading to misdiagnoses. In HJNM and in other journals the importance of proper positioning of the heart of the patient to be examined by myocardial perfusion SPET stress/rest testing, has been emphasized. According to our knowledge, only three cases of truncation artifact during SPET myocardial perfusion imaging acquired with original SPET cameras, related to improper positioning in very thin patients, have been reported. In all cases, patients were examined according to a single day stress/rest technetium-99m-sestamibi protocol, using a dual 90 degree detector system, equipped with high resolution, parallel-hole collimators. However, several published manuscripts have underlined the significance of appropriate patients' positioning in myocardial perfusion scintigraphy using dedicated, cadmium-zinc-telluride (CZT) or small field-of-view cardiac SPET systems. A typical case is that of a 47 years old man (height 187cm, weight 67kg), heavy smoker, with atypical chest pain. He exercised very well according to the Bruce protocol, achieving 95% of maximal age-predicted heart-rate and a technetium-99m-tetrofosmin ((99m)Tc-TF) myocardial perfusion imaging with 370MBq of (99m)Tc-TF followed with a dual head camera (Infinia GE, USA), equipped with low-energy, high-resolution, parallel-hole collimators at 90° (L-mode configuration). Projection images were obtained from 45° RAO to 45° LPO position, in step and shoot mode (60 projections, 30sec per projection; matrix 64×64 and zoom 1.3). Auto body contour was not used. Unprocessed raw data, showed neither patient motion nor significant extracardiac activity that could result in false positive defects on

  4. Perfusion harmonic imaging of the human brain

    NASA Astrophysics Data System (ADS)

    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. Visual analysis of longitudinal brain tumor perfusion

    NASA Astrophysics Data System (ADS)

    Glaßer, Sylvia; Oeltze, Steffen; Preim, Uta; Bjørnerud, Atle; Hauser, Helwig; Preim, Bernhard

    2013-02-01

    In clinical research on diagnosis and evaluation of brain tumors, longitudinal perfusion MRI studies are acquired for tumor grading as well as to monitor and assess treatment response and patient prognosis. Within this work, we demonstrate how visual analysis techniques can be adapted to multidimensional datasets from such studies within a framework to support the computer-aided diagnosis of brain tumors. Our solution builds on two innovations: First, we introduce a pipeline yielding comparative, co-registered quantitative perfusion parameter maps over all time steps of the longitudinal study. Second, based on these time-dependent parameter maps, visual analysis methods were developed and adapted to reveal valuable insight into tumor progression, especially regarding the clinical research area of low grade glioma transformation into high grade gliomas. Our examination of four longitudinal brain studies demonstrates the suitability of the presented visual analysis methods and comprises new possibilities for the clinical researcher to characterize the development of low grade gliomas.

  6. Quantification of brain perfusion with tracers retained by the brain

    SciTech Connect

    Pupi, A.; Bacciottini, L.; De Cristofaro, M.T.R.; Formiconi, A.R.; Castagnoli, A.

    1991-12-31

    Almost a decade ago, tracers, labelled with {sup 123}I and {sup 99m}Tc, that are retained by the brain, started to be used for studies of regional brain perfusion (regional cerebral blood flow, rCBF). To date, these tracers have been used for brain perfusion imaging with SPECT in brain disorders as well as for physiological activation protocols. Only seldom, however, have they been used in protocols that quantitatively measure rCBF. Nevertheless, comparative studies with perfusion reference tracers have repeatedly demonstrated that the brain uptake of these brain-retained tracers is correlated to perfusion, the major determinant of the distribution of these tracers in the brain. The brain kinetics of {sup 99m}Tc HMPAO, which is the tracer most commonly used, was described with a two-compartment tissue model. The theoretical approach, which is, in itself, sufficient for modeling quantitative measurements with {sup 99m}Tc HMPAO, initially suggested the possibility of empirically narrowing the distance between the brain`s regional uptake of the tracer and rCBF with a linearization algorithm which uses the cerebellum as the reference region. The value of this empirical method is hampered by the fact that the cerebellum can be involved in cerebrovascular disease (i.e. cerebellar diaschisis) as well as in several other brain disorders (e.g. anxiety, and dementia of the Alzheimer type). It also was proposed that different reference regions (occipital, whole slice, or whole brain) should be selected in relation to the brain disorder under study. However, this approach does not solve the main problem because it does not equip us with a reliable tool to evaluate rCBF with a high predictive value, and, at the same time, to reduce intersubject variability. The solution would be to measure a quantitative parameter which directly reflects rCBF, such as the unidirectional influx constant of the freely diffusible flow-limited tracers. 45 refs., 3 figs., 1 tab.

  7. The pediatric template of brain perfusion

    PubMed Central

    Avants, Brian B; Duda, Jeffrey T; Kilroy, Emily; Krasileva, Kate; Jann, Kay; Kandel, Benjamin T; Tustison, Nicholas J; Yan, Lirong; Jog, Mayank; Smith, Robert; Wang, Yi; Dapretto, Mirella; Wang, Danny J J

    2015-01-01

    Magnetic resonance imaging (MRI) captures the dynamics of brain development with multiple modalities that quantify both structure and function. These measurements may yield valuable insights into the neural patterns that mark healthy maturation or that identify early risk for psychiatric disorder. The Pediatric Template of Brain Perfusion (PTBP) is a free and public neuroimaging resource that will help accelerate the understanding of childhood brain development as seen through the lens of multiple modality neuroimaging and in relation to cognitive and environmental factors. The PTBP uses cross-sectional and longitudinal MRI to quantify cortex, white matter, resting state functional connectivity and brain perfusion, as measured by Arterial Spin Labeling (ASL), in 120 children 7–18 years of age. We describe the PTBP and show, as a demonstration of validity, that global summary measurements capture the trajectories that demarcate critical turning points in brain maturation. This novel resource will allow a more detailed understanding of the network-level, structural and functional landmarks that are obtained during normal adolescent brain development. PMID:25977810

  8. {sup 99m}Tc radiopharmaceuticals for brain perfusion imaging

    SciTech Connect

    Deutsch, E.; Volkert, W.A.

    1991-12-31

    It is well established that small, neutral, lipophilic technetium complexes can diffuse into the brain and then be trapped intracellularly by a variety of mechanisms. A more detailed understanding of the structural and chemical parameters which promote efficient diffusion into the brain, and which underlie the trapping mechanisms, will be necessary to delineate the clinical relevance of current agents, and to design improved technetium 99 pharmaceuticals. Current technetium 99 brain-perfusion imaging agents do not show ideal characteristics of brain uptake and retention. Furthermore, significant fractions of the technetium 99 complexes are lost between site of injection and the brain. Thus, it is difficult to use these current agents to quantitate regional cerebral blood flow. Nevertheless, these agents are proving extremely valuable for the SPECT evaluation of abnormalities in brain perfusion patients with neurological disorders.

  9. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    NASA Astrophysics Data System (ADS)

    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.

  10. Brain perfusion in acute and chronic hyperglycemia in rats

    SciTech Connect

    Kikano, G.E.; LaManna, J.C.; Harik, S.I. )

    1989-08-01

    Recent studies show that acute and chronic hyperglycemia cause a diffuse decrease in regional cerebral blood flow and that chronic hyperglycemia decreases the brain L-glucose space. Since these changes can be caused by a decreased density of perfused brain capillaries, we used 30 adult male Wistar rats to study the effect of acute and chronic hyperglycemia on (1) the brain intravascular space using radioiodinated albumin, (2) the anatomic density of brain capillaries using alkaline phosphatase histochemistry, and (3) the fraction of brain capillaries that are perfused using the fluorescein isothiocyanate-dextran method. Our results indicate that acute and chronic hyperglycemia do not affect the brain intravascular space nor the anatomic density of brain capillaries. Also, there were no differences in capillary recruitment among normoglycemic, acutely hyperglycemic, and chronically hyperglycemic rats. These results suggest that the shrinkage of the brain L-glucose space in chronic hyperglycemia is more likely due to changes in the blood-brain barrier permeability to L-glucose.

  11. Clinical Brain Death with False Positive Radionuclide Cerebral Perfusion Scans

    PubMed Central

    Venkatram, Sindhaghatta; Bughio, Sara; Diaz-Fuentes, Gilda

    2015-01-01

    Practice guidelines from the American Academy of Neurology for the determination of brain death in adults define brain death as “the irreversible loss of function of the brain, including the brainstem.” Neurological determination of brain death is primarily based on clinical examination; if clinical criteria are met, a definitive confirmatory test is indicated. The apnea test remains the gold standard for confirmation. In patients with factors that confound the clinical determination or when apnea tests cannot safely be performed, an ancillary test is required to confirm brain death. Confirmatory ancillary tests for brain death include (a) tests of electrical activity (electroencephalography (EEG) and somatosensory evoked potentials) and (b) radiologic examinations of blood flow (contrast angiography, transcranial Doppler ultrasound (TCD), and radionuclide methods). Of these, however, radionuclide studies are used most commonly. Here we present data from two patients with a false positive Radionuclide Cerebral Perfusion Scan (RCPS). PMID:26167307

  12. Technological advances in MRI measurement of brain perfusion.

    PubMed

    Duyn, Jeff H; van Gelderen, Peter; Talagala, Lalith; Koretsky, Alan; de Zwart, Jacco A

    2005-12-01

    Measurement of brain perfusion using arterial spin labeling (ASL) or dynamic susceptibility contrast (DSC) based MRI has many potential important clinical applications. However, the clinical application of perfusion MRI has been limited by a number of factors, including a relatively poor spatial resolution, limited volume coverage, and low signal-to-noise ratio (SNR). It is difficult to improve any of these aspects because both ASL and DSC methods require rapid image acquisition. In this report, recent methodological developments are discussed that alleviate some of these limitations and make perfusion MRI more suitable for clinical application. In particular, the availability of high magnetic field strength systems, increased gradient performance, the use of RF coil arrays and parallel imaging, and increasing pulse sequence efficiency allow for increased image acquisition speed and improved SNR. The use of parallel imaging facilitates the trade-off of SNR for increases in spatial resolution. As a demonstration, we obtained DSC and ASL perfusion images at 3.0 T and 7.0 T with multichannel RF coils and parallel imaging, which allowed us to obtain high-quality images with in-plane voxel sizes of 1.5 x 1.5 mm(2). PMID:16267852

  13. [Antegrade unilateral perfusion of the brain through the brachiocephalic trunk in operations on the aortic arch].

    PubMed

    Kozlov, B N; Panfilov, D S; Kuznetsov, M S; Ponomarenko, I V; Nasrashvili, G G; Shipulin, V M

    2016-01-01

    Presented herein is a technique of unilateral antegrade perfusion of the brain in operations on the aortic arch. The method makes it possible to perform both systemic artificial circulation and adequate physiological perfusion of the brain, promoting minimization of the number of neurological complications. PMID:27100557

  14. Iterative blind deconvolution in magnetic resonance brain perfusion imaging.

    PubMed

    Grüner, Renate; Taxt, Torfinn

    2006-04-01

    In first pass magnetic resonance brain perfusion imaging, arterial input functions are used in the deconvolution of the observed contrast concentrations to obtain quantitative hemodynamic parameters. Ideally, arterial input functions should be measured in each imaged voxel to eliminate the effects of delay and dispersion of the contrast agent from the injection site. An approach based on iterative blind deconvolution with the Richardson-Lucy algorithm is proposed for the simultaneous estimation of voxel-specific arterial input functions and voxel-specific tissue residue functions. An extended contrast concentration model was used to separate the first pass bolus from additional recirculation and leakage signals. The extended model was evaluated using in vivo data. Computer simulations examined the feasibility of iterative blind deconvolution in perfusion imaging. Preliminary in vivo results from a patient with fibromuscular dysplasia showed territories with delayed/dispersed arterial input functions that coincided with the location of territories supplied by collateral circulation as described from the complete radiologic examination. Higher flow values and shorter mean transit times compared to conventional methods were obtained in these areas, suggesting that the effects of dispersion were minimized. The in vivo estimated arterial input functions visualized the patient's blood supply patterns as a function of time. PMID:16526016

  15. Quantitative iodine-123 IMP imaging of brain perfusion in schizophrenia.

    PubMed

    Cohen, M B; Lake, R R; Graham, L S; King, M A; Kling, A S; Fitten, L J; O'Rear, J; Bronca, G A; Gan, M; Servrin, R

    1989-10-01

    Decreased perfusion in the frontal lobes of patients with chronic schizophrenia has been reported by multiple observes using a variety of techniques. Other observers have been unable to confirm this finding using similar techniques. In this study quantitative single photon emission computed tomography brain imaging was performed using p,5n [123I]IMP in five normal subjects and ten chronically medicated patients with schizophrenia. The acquisition data were preprocessed with an image dependent Metz filter and reconstructed using a ramp filtered back projection technique. The uptake in each of 50 regions of interest in each subject was normalized to the uptake in the cerebellum. There were no significant confirmed differences in the comparable ratios of normal subjects and patients with schizophrenia even at the p = 0.15 level. "Hypofrontality" was not observed. PMID:2795201

  16. Quantitative iodine-123 IMP imaging of brain perfusion in schizophrenia

    SciTech Connect

    Cohen, M.B.; Lake, R.R.; Graham, L.S.; King, M.A.; Kling, A.S.; Fitten, L.J.; O'Rear, J.; Bronca, G.A.; Gan, M.; Servrin, R. )

    1989-10-01

    Decreased perfusion in the frontal lobes of patients with chronic schizophrenia has been reported by multiple observes using a variety of techniques. Other observers have been unable to confirm this finding using similar techniques. In this study quantitative single photon emission computed tomography brain imaging was performed using p,5n ({sup 123}I)IMP in five normal subjects and ten chronically medicated patients with schizophrenia. The acquisition data were preprocessed with an image dependent Metz filter and reconstructed using a ramp filtered back projection technique. The uptake in each of 50 regions of interest in each subject was normalized to the uptake in the cerebellum. There were no significant confirmed differences in the comparable ratios of normal subjects and patients with schizophrenia even at the p = 0.15 level. Hypofrontality was not observed.

  17. Brain perfusion in polysubstance users: Relationship to substance and tobacco use, cognition, and self-regulation*

    PubMed Central

    Murray, Donna E.; Durazzo, Timothy C.; Mon, Anderson; Schmidt, Thomas P.; Meyerhoff, Dieter J.

    2015-01-01

    Background Brain perfusion is altered in both alcohol dependence and stimulant dependence. Although most substance users also abuse/depend on alcohol concurrently (polysubstance users; PSU), rigorous perfusion research in PSU is limited. Also, the relationships of perfusion abnormalities with cognition, impulsivity or decision making are not well known. Methods Arterial spin labeling MRI and neuropsychological measures assessed perfusion levels and neurocognition in 20 alcohol dependent individuals with comorbid stimulant dependence (PSU), 26 individuals dependent on alcohol only (ALC), and 31 light/non-drinking controls (LD). The patient groups included smokers and non-smokers. Results ALC had lower perfusion than LD in subcortical and cortical brain regions including the brain reward/executive oversight system (BREOS). Contrary to our hypothesis, regional perfusion was generally not lower in PSU than ALC. However, smoking PSU had lower perfusion than smoking ALC in several regions, including BREOS. Lower BREOS perfusion related to greater drinking severity in smoking substance users and to greater smoking severity in smoking ALC. Lower regional perfusion in ALC and PSU correlated with worse performance in different cognitive domains; smoking status affected perfusion-cognition relationships in ALC only. Lower BREOS perfusion in both substance using groups related to higher impulsivity. Conclusion Although regional perfusion was not decreased in PSU as a group, the combination of cigarette smoking and polysubstance use is strongly related to hypoperfusion in important cortical and subcortical regions. As lower perfusion relates to greater smoking severity, worse cognition and higher impulsivity, smoking cessation is warranted for treatment-seeking PSU and ALC. PMID:25772434

  18. Brain Perfusion in Corticobasal Syndrome with Progressive Aphasia

    PubMed Central

    Abe, Yoshitake; Kimura, Noriyuki; Goto, Megumi; Aso, Yasuhiro; Matsubara, Etsuro

    2016-01-01

    Background Brain perfusion may differ between patients with corticobasal syndrome (CBS) with and without aphasia. Methods Twenty-six (9 males and 17 females; mean age 76 ± 5.3 years) patients with CBS were enrolled in the study. Brain MRI and single-photon emission computed tomography were performed in all subjects. Language was evaluated using the Standard Language Test of Aphasia. The patients were divided into two subgroups according to the presence or absence of progressive aphasia. Differences in the regional cerebral blood flow (rCBF) between the two groups were detected based on voxel-by-voxel group analysis using Statistical Parametric Mapping 8. Results All patients exhibited asymmetric motor symptoms and signs, including limb apraxia, bradykinesia, and akinetic rigidity. Of 26 patients, 9 had a clinically obvious language disturbance, characterized as nonfluent aphasia. Almost all CBS patients with aphasia exhibited cortical atrophy predominantly in the left frontal and temporal lobes with widening of the Sylvian fissure on MRI. The rCBF in the left middle frontal gyrus differed significantly between CBS patients with and without aphasia. Conclusion CBS patients with aphasia exhibit motor symptoms predominantly on the right side and cortical atrophy mainly in the left perisylvian cortices. In particular, left frontal dysfunction might be related to nonfluent aphasia in CBS. PMID:27195001

  19. Interobserver variation in diagnosis of dementia by brain perfusion SPECT.

    PubMed

    Honda, Norinari; Machida, Kikuo; Hosono, Makoto; Matsumoto, Tohru; Matsuda, Hiroshi; Oshima, Motoo; Koizumi, Kiyoshi; Kosuda, Shigeru; Momose, Toshimitsu; Mori, Yutaka; Hashimoto, Jun; Shimizu, Yuji

    2002-01-01

    Brain perfusion SPECT (BP-SPECT) has characteristic patterns of abnormality, enabling the differential diagnosis of dementia. The purpose of this study was to measure interobserver variations in the diagnosis of dementia using BP-SPECT. BP-SPECT images of 57 cases, 19 of Alzheimer's disease (AD), eight of multi-infarct dementia (MID), three of Pick's disease, five of other dementias, and 22 normal controls, were interpreted by ten nuclear medicine physicians with varying levels of experience. Brain MR images of the cases were then interpreted apart from SPECT. The physicians independently rated all of the diagnoses listed beforehand according to a five-point scale, with clinical information provided. Receiver-operating characteristic (ROC) curves and the area under the ROC curve (Az) were calculated. Az varied from 0.48 to 0.87. Mean Az's were significantly larger (p<0.05) in the diagnosis by SPECT than in that by MRI (0.715 and 0.629 for dementia vs. normal, 0.670 and 0.560 for AD or MID vs. normal, 0.610 and 0.416 for AD vs. normal, and 0.672 and 0.412 for AD vs. MID, respectively). Considerable interobserver variation was present in BP-SPECT interpretation. BP-SPECT may be more effective for the evaluation of dementia than MRI when the same nuclear medicine physicians interpret both images. PMID:12553341

  20. Neuropsychological Correlates of Brain Perfusion SPECT in Patients with Macrophagic Myofasciitis

    PubMed Central

    Van Der Gucht, Axel; Aouizerate, Jessie; Evangelista, Eva; Chalaye, Julia; Gherardi, Romain K.; Ragunathan-Thangarajah, Nilusha; Bachoud-Levi, Anne-Catherine; Authier, François-Jérôme

    2015-01-01

    Background Patients with aluminum hydroxide adjuvant-induced macrophagic myofasciitis (MMF) complain of arthromyalgias, chronic fatigue and cognitive deficits. This study aimed to characterize brain perfusion in these patients. Methods Brain perfusion SPECT was performed in 76 consecutive patients (aged 49±10 y) followed in the Garches-Necker-Mondor-Hendaye reference center for rare neuromuscular diseases. Images were acquired 30 min after intravenous injection of 925 MBq 99mTc-ethylcysteinate dimer (ECD) at rest. All patients also underwent a comprehensive battery of neuropsychological tests, within 1.3±5.5 mo from SPECT. Statistical parametric maps (SPM12) were obtained for each test using linear regressions between each performance score and brain perfusion, with adjustment for age, sex, socio-cultural level and time delay between brain SPECT and neuropsychological testing. Results SPM analysis revealed positive correlation between neuropsychological scores (mostly exploring executive functions) and brain perfusion in the posterior associative cortex, including cuneus/precuneus/occipital lingual areas, the periventricular white matter/corpus callosum, and the cerebellum, while negative correlation was found with amygdalo-hippocampal/entorhinal complexes. A positive correlation was also observed between brain perfusion and the posterior associative cortex when the time elapsed since last vaccine injection was investigated. Conclusions Brain perfusion SPECT showed a pattern of cortical and subcortical changes in accordance with the MMF-associated cognitive disorder previously described. These results provide a neurobiological substrate for brain dysfunction in aluminum hydroxide adjuvant-induced MMF patients. PMID:26030650

  1. Contrast-enhanced diffuse optical tomography of brain perfusion in humans using ICG

    NASA Astrophysics Data System (ADS)

    Habermehl, Christina; Schmitz, Christoph; Steinbrink, Jens

    2012-02-01

    Regular monitoring of brain perfusion at the bedside in neurointensive care is desirable. Currently used imaging modalities are not suited for constant monitoring and often require a transport of the patient. Noninvasive near infrared spectroscopy (NIRS) in combination with an injection of a safe dye (indocyanine green, ICG) could serve as a quasi-continuous brain perfusion monitor. In this work, we evaluate prerequisites for the development of a brain perfusion monitor using continuous wave (cw) NIRS technique. We present results from a high-resolution diffuse optical tomography (HR-DOT) experiment in humans demonstrating the separation of signals from skin from the brain. This technique can help to monitor neurointensive care patients on a regular basis, detecting changes in cortical perfusion in time.

  2. Whole-Brain Computed Tomographic Perfusion Imaging in Acute Cerebral Venous Sinus Thrombosis

    PubMed Central

    Mokin, Maxim; Ciambella, Chelsey C.; Masud, Muhammad W.; Levy, Elad I.; Snyder, Kenneth V.; Siddiqui, Adnan H.

    2016-01-01

    Background Acute cerebral venous sinus thrombosis (VST) can be difficult to diagnose because of its diverse clinical presentation. The utility of perfusion imaging for diagnosing VST is not well understood. Summary We retrospectively reviewed cases of acute VST in patients who underwent whole-brain (320-detector-row) computed tomographic (CT) perfusion imaging in combination with craniocervical CT venography. Perfusion maps that were analyzed included cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time, and time to peak. Among the 10 patients with acute VST included in this study, 9 had perfusion abnormalities. All perfusion abnormalities were localized in areas adjacent to the occluded sinus and did not match typical anterior or posterior circulation arterial territories. Bilateral perfusion deficits were seen in 4 cases. In 2 cases, parenchymal hemorrhage was diagnosed on noncontrast CT imaging; in those cases, focal CBV and CBF were reduced. Key Messages Whole-brain CT perfusion imaging with 320-detector-row scanners can further assist in establishing the diagnosis of VST by detecting perfusion abnormalities corresponding to venous and not arterial territories. CT perfusion could assist in the differentiation between focal reversible changes, such as those caused by vasogenic edema, and irreversible changes due to infarction. PMID:27051406

  3. Brain tumors and synchrotron radiation: Methodological developments in quantitative brain perfusion imaging and radiation therapy

    SciTech Connect

    Adam, Jean-Francois

    2005-04-01

    High-grade gliomas are the most frequent type of primary brain tumors in adults. Unfortunately, the management of glioblastomas is still mainly palliative and remains a difficult challenge, despite advances in brain tumor molecular biology and in some emerging therapies. Synchrotron radiation opens fields for medical imaging and radiation therapy by using monochromatic intense x-ray beams. It is now well known that angiogenesis plays a critical role in the tumor growth process and that brain perfusion is representative of the tumor mitotic activity. Synchrotron radiation quantitative computed tomography (SRCT) is one of the most accurate techniques for measuring in vivo contrast agent concentration and thus computing precise and accurate absolute values of the brain perfusion key parameters. The methodological developments of SRCT absolute brain perfusion measurements as well as their preclinical validation are detailed in this thesis. In particular, absolute cerebral volume and blood brain barrier permeability high-resolution (pixel size <50x50 {mu}m{sup 2}) parametric maps were reported. In conventional radiotherapy, the treatment of these tumors remains a delicate challenge, because the damages to the surrounding normal brain tissue limit the amount of radiation that can be delivered. One strategy to overcome this limitation is to infuse an iodinated contrast agent to the patient during the irradiation. The contrast agent accumulates in the tumor, through the broken blood brain barrier, and the irradiation is performed with kilovoltage x rays, in tomography mode, the tumor being located at the center of rotation and the beam size adjusted to the tumor dimensions. The dose enhancement results from the photoelectric effect on the heavy element and from the irradiation geometry. Synchrotron beams, providing high intensity, tunable monochromatic x rays, are ideal for this treatment. The beam properties allow the selection of monochromatic irradiation, at the optimal

  4. Regional brain perfusion in 10 normal dogs measured using Technetium-99m ethyl cysteinate dimer spect.

    PubMed

    Peremans, K; De Bondt, P; Audenaert, K; Van Laere, K; Gielen, I; Koole, M; Versijpt, J; Van Bree, H; Verschooten, F; Dierckx, R

    2001-01-01

    Single photon emission computed tomography (SPECT) of the brain using perfusion tracers allows estimation of regional brain perfusion. This allows in vivo examination of brain function in the setting of neuropsychologic and pathophysiologic changes. However functional imaging data on brain perfusion in dogs are limited. Hence, the aim of this study was to determine the scintigraphic regional perfusion pattern of the normal canine brain. Ten healthy shepherd type dogs were injected with 925 MBq Technetium-99m ethyl cysteinate (ECD) 20 minutes before the examination. Acquisition was performed using a triple head gamma camera equipped with fanbeam collimators. Uniform attenuation correction and triple energy window correction were applied. Computed tomographic images were obtained from the same dogs, reoriented along the orbito-meatal axis and SPECT perfusion data were coregistered to the CT-volume data. Based on morphological and suggested brain divisions, regions-of-interest (ROIs) were defined for the bilateral frontocerebral, temporocerebral, parietocerebral, occipitocerebral, cerebellar, thalamic, and striatal area. Regional count density was normalized on total counts. All dogs had the highest uptake in the thalamic/striatal area compared to a rather homogeneous cerebral uptake. No significant left/right count differences were found, but a rostro-caudal gradient (+12-13%) was present. In this group, age and gender did not influence the perfusion pattern. PMID:11768526

  5. Pattern of brain blood perfusion in tinnitus patients using technetium-99m SPECT imaging

    PubMed Central

    Mahmoudian, Saeid; Farhadi, Mohammad; Gholami, Saeid; Saddadi, Fariba; Karimian, Ali Reza; Mirzaei, Mohammad; Ghoreyshi, Esmaeel; Ahmadizadeh, Majid; Lenarz, Thomas

    2012-01-01

    Background and Purpose: Tinnitus is associated with an increased activity in central auditory system as demonstrated by neuroimaging studies. Brain perfusion scanning using single photon emission computed tomography (SPECT) was done to understand the pattern of brain blood perfusion of tinnitus subjects and find the areas which are mostly abnormal in these patients. Materials and Methods: A number of 122 patients with tinnitus were enrolled to this cross-sectional study. They underwent SPECT and magnetic resonance imaging (MRI) of brain, and the images were fused to find the regions with abnormal perfusion. Results: SPECT scan results were abnormal in 101 patients (83%). Most patients had bilateral abnormal perfusion (N = 65, 53.3%), and most subjects had abnormality in middle-temporal gyrus (N = 83, 68%) and temporoparietal cortex (N = 46, 37.7%). Patients with multifocal involvement had the least mean age than other 2 groups (patients with no abnormality and unifocal abnormality) (P value = 0.045). Conclusions: Brain blood perfusion pattern differs in patient with tinnitus than others. These patients have brain perfusion abnormality, mostly in auditory gyrus (middle temporal) and associative cortex (temporoparietal cortex). Multifocal abnormalities might be due to more cognitive and emotional brain centers involvement due to tinnitus or more stress and anxiety of tinnitus in the young patients. PMID:23267375

  6. Correction for partial volume effects in brain perfusion ECT imaging

    NASA Astrophysics Data System (ADS)

    Koole, Michel; Staelens, Steven; Van de Walle, Rik; Lemahieu, Ignace L.

    2003-05-01

    The accurate quantification of brain perfusion for emission computed tomography data (PET-SPECT) is limited by partial volume effects (PVE). This study presents a new approach to estimate accurately the true tissue tracer activity within the grey matter tissue compartment. The methodology is based on the availability of additional anatomical side information and on the assumption that activity concentration within the white matter tissue compartment is constant. Starting from an initial estimate for the white matter grey matter activity, the true tracer activity within the grey matter tissue compartment is estimated by an alternating ML-EM-algorithm. During the updating step the constant activity concentration within the white matter compartment is modelled in the forward projection in order to reconstruct the true activity distribution within the grey matter tissue compartment, hence reducing partial volume averaging. Consequently the estimate for the constant activity in the white matter tissue compartment is updated based on the new estimated activity distribution in the grey matter tissue compartment. We have tested this methodology by means of computer simulations. A T1-weighted MR brainscan of a patient was segmented into white matter, grey matter and cerebrospinal fluid, using the segmentation package of the SPM-software (Statistical Parametric Mapping). The segmented grey and white matter were used to simulate a SPECT acquisition, modelling the noise and the distance dependant detector response. Scatter and attenuation were ignored. Following the above described strategy, simulations have shown it is possible to reconstruct the true activity distribution for the grey matter tissue compartment (activity/tissue volume), assuming constant activity in the white matter tissue compartment.

  7. Non Tumor Perfusion Changes Following Stereotactic Radiosurgery to Brain Metastases

    PubMed Central

    Jakubovic, Raphael; Sahgal, Arjun; Ruschin, Mark; Pejović-Milić, Ana; Milwid, Rachael; Aviv, Richard I.

    2015-01-01

    Purpose: To evaluate early perfusion changes in normal tissue following stereotactic radiosurgery (SRS). Methods: Nineteen patients harboring twenty-two brain metastases treated with SRS were imaged with dynamic susceptibility magnetic resonance imaging (DSC MRI) at baseline, 1 week and 1 month post SRS. Relative cerebral blood volume and flow (rCBV and rCBF) ratios were evaluated outside of tumor within a combined region of interest (ROI) and separately within gray matter (GM) and white matter (WM) ROIs. Three-dimensional dose distribution from each SRS plan was divided into six regions: (1) <2 Gy; (2) 2-5 Gy; (3) 5-10 Gy; (4) 10-12 Gy; (5) 12-16 Gy; and (6) >16 Gy. rCBV and rCBF ratio differences between baseline, 1 week and 1 month were compared. Best linear fit plots quantified normal tissue dose-dependency. Results: Significant rCBV ratio increases were present between baseline and 1 month for all ROIs and dose ranges except for WM ROI receiving <2 Gy. rCBV ratio for all ROIs was maximally increased from baseline to 1 month with the greatest changes occurring within the 5-10 Gy dose range (53.1%). rCBF ratio was maximally increased from baseline to 1 month for all ROIs within the 5-10 Gy dose range (33.9-45.0%). Both rCBV and rCBF ratios were most elevated within GM ROIs. A weak, positive but not significant association between dose, rCBV and rCBF ratio was demonstrated. Progressive rCBV and rCBF ratio increased with dose up to 10 Gy at 1 month. Conclusion: Normal tissue response following SRS can be characterized by dose, tissue, and time specific increases in rCBV and rCBF ratio. PMID:26269612

  8. Influence of Thin Slice Reconstruction on CT Brain Perfusion Analysis

    PubMed Central

    Bennink, Edwin; Oosterbroek, Jaap; Horsch, Alexander D.; Dankbaar, Jan Willem; Velthuis, Birgitta K.; Viergever, Max A.; de Jong, Hugo W. A. M.

    2015-01-01

    Objectives Although CT scanners generally allow dynamic acquisition of thin slices (1 mm), thick slice (≥5 mm) reconstruction is commonly used for stroke imaging to reduce data, processing time, and noise level. Thin slice CT perfusion (CTP) reconstruction may suffer less from partial volume effects, and thus yield more accurate quantitative results with increased resolution. Before thin slice protocols are to be introduced clinically, it needs to be ensured that this does not affect overall CTP constancy. We studied the influence of thin slice reconstruction on average perfusion values by comparing it with standard thick slice reconstruction. Materials and Methods From 50 patient studies, absolute and relative hemisphere averaged estimates of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and permeability-surface area product (PS) were analyzed using 0.8, 2.4, 4.8, and 9.6 mm slice reconstructions. Specifically, the influence of Gaussian and bilateral filtering, the arterial input function (AIF), and motion correction on the perfusion values was investigated. Results Bilateral filtering gave noise levels comparable to isotropic Gaussian filtering, with less partial volume effects. Absolute CBF, CBV and PS were 22%, 14% and 46% lower with 0.8 mm than with 4.8 mm slices. If the AIF and motion correction were based on thin slices prior to reconstruction of thicker slices, these differences reduced to 3%, 4% and 3%. The effect of slice thickness on relative values was very small. Conclusions This study shows that thin slice reconstruction for CTP with unaltered acquisition protocol gives relative perfusion values without clinically relevant bias. It does however affect absolute perfusion values, of which CBF and CBV are most sensitive. Partial volume effects in large arteries and veins lead to overestimation of these values. The effects of reconstruction slice thickness should be taken into account when absolute perfusion values are

  9. Challenges for non-invasive brain perfusion quantification using arterial spin labeling.

    PubMed

    Sousa, I; Santos, N; Sanches, J; Figueiredo, P

    2011-03-29

    Arterial Spin Labeling (ASL) sequences for perfusion Magnetic Resonance Imaging (MRI) have recently become available to be used in the clinical practice, offering a completely non-invasive technique for the quantitative evaluation of brain perfusion. Despite its great potential, ASL perfusion imaging still presents important methodological challenges before its incorporation in routine protocols. Specifically, in some pathological conditions in which the cerebrovascular dynamics is altered, the standard application of ASL may lead to measurement errors. In these cases, it would be possible to estimate perfusion, as well as arterial transit times, by collecting images at multiple time points and then fitting a mathematical model to the data. This approach can be optimized by selecting a set of optimal imaging time points and incorporating knowledge about the physiological distributions of the parameters into the model estimation procedures. In this study, we address the challenges that arise in the measurement of brain perfusion using PASL, due to variations in the arterial transit times, by estimating the errors produced using different types of acquisitions and proposing methods for minimizing such errors. We show by simulation that multiple inversion time ASL acquisitions are expected to reduce measurement errors relative to standard approaches. In data collected from a group of subjects, we further observed reduced inter-subject variability in perfusion measurements when using a multiple versus single inversion time acquisitions. Both measurement errors and variability were further reduced if optimized acquisition and analysis techniques were employed. PMID:24059574

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

    SciTech Connect

    Tumeh, S.S.; Nagel, J.S.; English, R.J.; Moore, M.; Holman, B.L. )

    1990-09-01

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

  11. Perfused drop microfluidic device for brain slice culture-based drug discovery.

    PubMed

    Liu, Jing; Pan, Liping; Cheng, Xuanhong; Berdichevsky, Yevgeny

    2016-06-01

    Living slices of brain tissue are widely used to model brain processes in vitro. In addition to basic neurophysiology studies, brain slices are also extensively used for pharmacology, toxicology, and drug discovery research. In these experiments, high parallelism and throughput are critical. Capability to conduct long-term electrical recording experiments may also be necessary to address disease processes that require protein synthesis and neural circuit rewiring. We developed a novel perfused drop microfluidic device for use with long term cultures of brain slices (organotypic cultures). Slices of hippocampus were placed into wells cut in polydimethylsiloxane (PDMS) film. Fluid level in the wells was hydrostatically controlled such that a drop was formed around each slice. The drops were continuously perfused with culture medium through microchannels. We found that viable organotypic hippocampal slice cultures could be maintained for at least 9 days in vitro. PDMS microfluidic network could be readily integrated with substrate-printed microelectrodes for parallel electrical recordings of multiple perfused organotypic cultures on a single MEA chip. We expect that this highly scalable perfused drop microfluidic device will facilitate high-throughput drug discovery and toxicology. PMID:27194028

  12. Whole-Brain CT Perfusion to Quantify Acute Ischemic Penumbra and Core.

    PubMed

    Lin, Longting; Bivard, Andrew; Krishnamurthy, Venkatesh; Levi, Christopher R; Parsons, Mark W

    2016-06-01

    Purpose To validate the use of perfusion computed tomography (CT) with whole-brain coverage to measure the ischemic penumbra and core and to compare its performance to that of limited-coverage perfusion CT. Materials and Methods Institutional ethics committee approval and informed consent were obtained. Patients (n = 296) who underwent 320-detector CT perfusion within 6 hours of the onset of ischemic stroke were studied. First, the ischemic volume at CT perfusion was compared with the penumbra and core reference values at magnetic resonance (MR) imaging to derive CT perfusion penumbra and core thresholds. Second, the thresholds were tested in a different group of patients to predict the final infarction at diffusion-weighted imaging 24 hours after CT perfusion. Third, the change in ischemic volume delineated by the optimal penumbra and core threshold was determined as the brain coverage was gradually reduced from 160 mm to 20 mm. The Wilcoxon signed-rank test, concordance correlation coefficient (CCC), and analysis of variance were used for the first, second, and third steps, respectively. Results CT perfusion at penumbra and core thresholds resulted in the least volumetric difference from MR imaging reference values with delay times greater than 3 seconds and delay-corrected cerebral blood flow of less than 30% (P = .34 and .33, respectively). When the thresholds were applied to the new group of patients, prediction of the final infarction was allowed with delay times greater than 3 seconds in patients with no recanalization of the occluded artery (CCC, 0.96 [95% confidence interval: 0.92, 0.98]) and with delay-corrected cerebral blood flow less than 30% in patients with complete recanalization (CCC, 0.91 [95% confidence interval: 0.83, 0.95]). However, the ischemic volume with a delay time greater than 3 seconds was underestimated when the brain coverage was reduced to 80 mm (P = .04) and the core volume measured as cerebral blood flow less than 30% was

  13. ASFNR recommendations for clinical performance of MR dynamic susceptibility contrast perfusion imaging of the brain.

    PubMed

    Welker, K; Boxerman, J; Kalnin, A; Kaufmann, T; Shiroishi, M; Wintermark, M

    2015-06-01

    MR perfusion imaging is becoming an increasingly common means of evaluating a variety of cerebral pathologies, including tumors and ischemia. In particular, there has been great interest in the use of MR perfusion imaging for both assessing brain tumor grade and for monitoring for tumor recurrence in previously treated patients. Of the various techniques devised for evaluating cerebral perfusion imaging, the dynamic susceptibility contrast method has been employed most widely among clinical MR imaging practitioners. However, when implementing DSC MR perfusion imaging in a contemporary radiology practice, a neuroradiologist is confronted with a large number of decisions. These include choices surrounding appropriate patient selection, scan-acquisition parameters, data-postprocessing methods, image interpretation, and reporting. Throughout the imaging literature, there is conflicting advice on these issues. In an effort to provide guidance to neuroradiologists struggling to implement DSC perfusion imaging in their MR imaging practice, the Clinical Practice Committee of the American Society of Functional Neuroradiology has provided the following recommendations. This guidance is based on review of the literature coupled with the practice experience of the authors. While the ASFNR acknowledges that alternate means of carrying out DSC perfusion imaging may yield clinically acceptable results, the following recommendations should provide a framework for achieving routine success in this complicated-but-rewarding aspect of neuroradiology MR imaging practice. PMID:25907520

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

    NASA Astrophysics Data System (ADS)

    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

  15. Quantitative Perfusion and Permeability Biomarkers in Brain Cancer from Tomographic CT and MR Images

    PubMed Central

    Eilaghi, Armin; Yeung, Timothy; d’Esterre, Christopher; Bauman, Glenn; Yartsev, Slav; Easaw, Jay; Fainardi, Enrico; Lee, Ting-Yim; Frayne, Richard

    2016-01-01

    Dynamic contrast-enhanced perfusion and permeability imaging, using computed tomography and magnetic resonance systems, are important techniques for assessing the vascular supply and hemodynamics of healthy brain parenchyma and tumors. These techniques can measure blood flow, blood volume, and blood–brain barrier permeability surface area product and, thus, may provide information complementary to clinical and pathological assessments. These have been used as biomarkers to enhance the treatment planning process, to optimize treatment decision-making, and to enable monitoring of the treatment noninvasively. In this review, the principles of magnetic resonance and computed tomography dynamic contrast-enhanced perfusion and permeability imaging are described (with an emphasis on their commonalities), and the potential values of these techniques for differentiating high-grade gliomas from other brain lesions, distinguishing true progression from posttreatment effects, and predicting survival after radiotherapy, chemotherapy, and antiangiogenic treatments are presented. PMID:27398030

  16. Dependence of Brain Intravoxel Incoherent Motion Perfusion Parameters on the Cardiac Cycle

    PubMed Central

    Federau, Christian; Hagmann, Patric; Maeder, Philippe; Müller, Markus; Meuli, Reto; Stuber, Matthias; O’Brien, Kieran

    2013-01-01

    Measurement of microvascular perfusion with Intravoxel Incoherent Motion (IVIM) MRI is gaining interest. Yet, the physiological influences on the IVIM perfusion parameters (“pseudo-diffusion” coefficient D*, perfusion fraction f, and flow related parameter fD*) remain insufficiently characterized. In this article, we hypothesize that D* and fD*, which depend on blood speed, should vary during the cardiac cycle. We extended the IVIM model to include time dependence of D* = D*(t), and demonstrate in the healthy human brain that both parameters D* and fD* are significantly larger during systole than diastole, while the diffusion coefficient D and f do not vary significantly. The results non-invasively demonstrate the pulsatility of the brain’s microvasculature. PMID:24023649

  17. Effects of perfusion on the mechanical behavior of the brain-exposed to hypergravity.

    PubMed

    Guillaume, A; Osmont, D; Gaffie, D; Sarron, J C; Quandieu, P

    1997-04-01

    In certain flight configurations, fighter pilots are exposed to high Gz acceleration which may induce inflight loss of consciousness (G-LOC). In order to study the mechanical effects induced by these accelerations on the cerebral structures, an experimental model has been developed in vitro. Fresh bovine brains were excised and placed in a transparent mold modeling the inside of the skull. Half of these brains were perfused during the experiment. This assembly was placed into the gondola of a centrifuge, in front of a camera lens. Displacements and deformations of the brains were filmed and recorded at different onset rates. Measurements were made after off-line digitalization of images. Experimental data were incorporated into a finite element calculation code whose mesh represented the brain. The applied behavior law was elastic, the structure being considered as homogeneous and isotropic. The first results concerned the elastic properties of the brains under hypergravity. The mean value of the Young's modulus of the nonperfused brain was 46.8 kPa, which corresponded to the values published in reference literature. For the perfused brains, the mean value of the Young's modulus was higher. The mean value of the equivalent Poisson's ratio was 0.35. In fact, contrary to impacts, the mechanical stimulation is long enough to allow fluid displacements. The mean value of the equivalent Poisson's ratio calculated in the present study should probably be increased since this study was performed post mortem. PMID:9075007

  18. Voxel-by-voxel analysis of brain SPECT perfusion in Fibromyalgia

    NASA Astrophysics Data System (ADS)

    Guedj, Eric; Taïeb, David; Cammilleri, Serge; Lussato, David; de Laforte, Catherine; Niboyet, Jean; Mundler, Olivier

    2007-02-01

    We evaluated brain perfusion SPECT at rest, without noxious stiumuli, in a homogeneous group of hyperalgesic FM patients. We performed a voxel-based analysis in comparison to a control group, matched for age and gender. Under such conditions, we made the assumption that significant cerebral perfusion abnormalities could be demonstrated, evidencing altered cerebral processing associated with spontaneous pain in FM patients. The secondary objective was to study the reversibility and the prognostic value of such possible perfusion abnormalities under specific treatment. Eighteen hyperalgesic FM women (mean age 48 yr; range 25-63 yr; ACR criteria) and 10 healthy women matched for age were enrolled in the study. A voxel-by-voxel group analysis was performed using SPM2 ( p<0.05, corrected for multiple comparisons). All brain SPECT were performed before any change was made in therapy in the pain care unit. A second SPECT was performed a month later after specific treatment by Ketamine. Compared to control subjects, we observed individual brain SPECT abnormalities in FM patients, confirmed by SPM2 analysis with hyperperfusion of the somatosensory cortex and hypoperfusion of the frontal, cingulate, medial temporal and cerebellar cortices. We also found that a medial frontal and anterior cingulate hypoperfusions were highly predictive (PPV=83%; NPV=91%) of non-response on Ketamine, and that only responders showed significant modification of brain perfusion, after treatment. In the present study performed without noxious stimuli in hyperalgesic FM patients, we found significant hyperperfusion in regions of the brain known to be involved in sensory dimension of pain processing and significant hypoperfusion in areas assumed to be associated with the affective dimension. As current pharmacological and non-pharmacological therapies act differently on both components of pain, we hypothesize that SPECT could be a valuable and readily available tool to guide individual therapeutic

  19. Acute effect of a high nitrate diet on brain perfusion in older adults

    PubMed Central

    Presley, Tennille D.; Morgan, Ashley R.; Bechtold, Erika; Clodfelter, William; Dove, Robin W.; Jennings, Janine M.; Kraft, Robert A.; King, S. Bruce; Laurienti, Paul J.; Rejeski, W. Jack; Burdette, Jonathan H.; Kim-Shapiro, Daniel B.; Miller, Gary D.

    2010-01-01

    Aims Poor blood flow and hypoxia/ischemia contribute to many disease states and may also be a factor in the decline of physical and cognitive function in aging. Nitrite has been discovered to be a vasodilator that is preferentially harnessed in hypoxia. Thus, both infused and inhaled nitrite are being studied as therapeutic agents for a variety of diseases. In addition, nitrite derived from nitrate in the diet has been shown to decrease blood pressure and improve exercise performance. Thus, dietary nitrate may also be important when increased blood flow in hypoxic or ischemic areas is indicated. These conditions could include age-associated dementia and cognitive decline. The goal of this study was to determine if dietary nitrate would increase cerebral blood flow in older adults. Methods and Results In this investigation we administered a high vs. low nitrate diet to older adults (74.7 ± 6.9 years) and measured cerebral perfusion using arterial spin labeling magnetic resonance imaging. We found that the high nitrate diet did not alter global cerebral perfusion, but did lead to increased regional cerebral perfusion in frontal lobe white matter, especially between the dorsolateral prefrontal cortex and anterior cingulate cortex. Conclusion These results suggest that dietary nitrate may be useful in improving regional brain perfusion in older adults in critical brain areas known to be involved in executive functioning. PMID:20951824

  20. Cholinergic and perfusion brain networks in Parkinson disease dementia

    PubMed Central

    McKeith, Ian G.; Burn, David J.; Wyper, David J.; O'Brien, John T.; Taylor, John-Paul

    2016-01-01

    Objective: To investigate muscarinic M1/M4 cholinergic networks in Parkinson disease dementia (PDD) and their association with changes in Mini-Mental State Examination (MMSE) after 12 weeks of treatment with donepezil. Methods: Forty-nine participants (25 PDD and 24 elderly controls) underwent 123I-QNB and 99mTc-exametazime SPECT scanning. We implemented voxel principal components (PC) analysis, producing a series of PC images of patterns of interrelated voxels across individuals. Linear regression analyses derived specific M1/M4 and perfusion spatial covariance patterns (SCPs). Results: We found an M1/M4 SCP of relative decreased binding in basal forebrain, temporal, striatum, insula, and anterior cingulate (F1,47 = 31.9, p < 0.001) in cholinesterase inhibitor–naive patients with PDD, implicating limbic-paralimbic and salience cholinergic networks. The corresponding regional cerebral blood flow SCP showed relative decreased uptake in temporoparietal and prefrontal areas (F1,47 = 177.5, p < 0.001) and nodes of the frontoparietal and default mode networks (DMN). The M1/M4 pattern that correlated with an improvement in MMSE (r = 0.58, p = 0.005) revealed relatively preserved/increased pre/medial/orbitofrontal, parietal, and posterior cingulate areas coinciding with the DMN and frontoparietal networks. Conclusion: Dysfunctional limbic-paralimbic and salience cholinergic networks were associated with PDD. Established cholinergic maintenance of the DMN and frontoparietal networks may be prerequisite for cognitive remediation following cholinergic treatment in this condition. PMID:27306636

  1. A Device for Long-Term Perfusion, Imaging, and Electrical Interfacing of Brain Tissue In vitro

    PubMed Central

    Killian, Nathaniel J.; Vernekar, Varadraj N.; Potter, Steve M.; Vukasinovic, Jelena

    2016-01-01

    Distributed microelectrode array (MEA) recordings from consistent, viable, ≥500 μm thick tissue preparations over time periods from days to weeks may aid in studying a wide range of problems in neurobiology that require in vivo-like organotypic morphology. Existing tools for electrically interfacing with organotypic slices do not address necrosis that inevitably occurs within thick slices with limited diffusion of nutrients and gas, and limited removal of waste. We developed an integrated device that enables long-term maintenance of thick, functionally active, brain tissue models using interstitial perfusion and distributed recordings from thick sections of explanted tissue on a perforated multi-electrode array. This novel device allows for automated culturing, in situ imaging, and extracellular multi-electrode interfacing with brain slices, 3-D cell cultures, and potentially other tissue culture models. The device is economical, easy to assemble, and integrable with standard electrophysiology tools. We found that convective perfusion through the culture thickness provided a functional benefit to the preparations as firing rates were generally higher in perfused cultures compared to their respective unperfused controls. This work is a step toward the development of integrated tools for days-long experiments with more consistent, healthier, thicker, and functionally more active tissue cultures with built-in distributed electrophysiological recording and stimulation functionality. The results may be useful for the study of normal processes, pathological conditions, and drug screening strategies currently hindered by the limitations of acute (a few hours long) brain slice preparations. PMID:27065793

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

    PubMed

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

    2014-04-01

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

  3. Brain perfusion SPECT with Brodmann areas analysis in differentiating frontotemporal dementia subtypes.

    PubMed

    Valotassiou, Varvara; Papatriantafyllou, John; Sifakis, Nikolaos; Tzavara, Chara; Tsougos, Ioannis; Psimadas, Dimitrios; Kapsalaki, Eftychia; Fezoulidis, Ioannis; Hadjigeorgiou, George; Georgoulias, Panagiotis

    2014-01-01

    Despite the known validity of clinical diagnostic criteria, significant overlap of clinical symptoms between Frontotemporal dementia (FTD) subtypes exists in several cases, resulting in great uncertainty of the diagnostic boundaries. We evaluated the perfusion between FTD subtypes using brain perfusion (99m)Tc-HMPAO SPECT with Brodmann areas (BA) mapping. NeuroGam software was applied on single photon emission computed tomographic (SPECT) studies for the semi-quantitative evaluation of perfusion in BA and the comparison with the software's normal database. We studied 91 consecutive FTD patients: 21 with behavioural variants (bvFTD), 39 with language variants (lvFTD) [12 with progressive non-fluent aphasia (PNFA), 27 with semantic dementia (SD)], and 31 patients with progressive supranuclear palsy (PSP)/corticobasal degeneration (CBD). Stepwise logistic regression analyses showed that the BA 28L and 32R could independently differentiate bvFTD from lvFTD, while the BA 8R and 25R could discriminate bvFTD from SD and PNFA, respectively. Additionally, BA 7R and 32R were found to discriminate bvFTD from CBD/PSP. The only BA that could differentiate SD from PNFA was 6L. BA 6R and 20L were found to independently differentiate CBD/PSP from lvFTD. Moreover, BA 20L and 22R could discriminate CBD/PSP from PNFA, while BA 6R, 20L and 45R were found to independently discriminate CBD/PSP from SD. Brain perfusion SPECT with BA mapping can be a useful additional tool in differentiating FTD variants by improving the definition of brain areas that are specifically implicated, resulting in a more accurate differential diagnosis in atypical or uncertain forms of FTD. PMID:25387340

  4. Sleep Deprivation Reveals Altered Brain Perfusion Patterns in Somnambulism

    PubMed Central

    Dang-Vu, Thien Thanh; Zadra, Antonio; Labelle, Marc-Antoine; Petit, Dominique; Soucy, Jean-Paul; Montplaisir, Jacques

    2015-01-01

    Background Despite its high prevalence, relatively little is known about the pathophysiology of somnambulism. Increasing evidence indicates that somnambulism is associated with functional abnormalities during wakefulness and that sleep deprivation constitutes an important drive that facilitates sleepwalking in predisposed patients. Here, we studied the neural mechanisms associated with somnambulism using Single Photon Emission Computed Tomography (SPECT) with 99mTc-Ethylene Cysteinate Dimer (ECD), during wakefulness and after sleep deprivation. Methods Ten adult sleepwalkers and twelve controls with normal sleep were scanned using 99mTc-ECD SPECT in morning wakefulness after a full night of sleep. Eight of the sleepwalkers and nine of the controls were also scanned during wakefulness after a night of total sleep deprivation. Between-group comparisons of regional cerebral blood flow (rCBF) were performed to characterize brain activity patterns during wakefulness in sleepwalkers. Results During wakefulness following a night of total sleep deprivation, rCBF was decreased bilaterally in the inferior temporal gyrus in sleepwalkers compared to controls. Conclusions Functional neural abnormalities can be observed during wakefulness in somnambulism, particularly after sleep deprivation and in the inferior temporal cortex. Sleep deprivation thus not only facilitates the occurrence of sleepwalking episodes, but also uncovers patterns of neural dysfunction that characterize sleepwalkers during wakefulness. PMID:26241047

  5. Perfusion deficits in patients with mild traumatic brain injury characterized by dynamic susceptibility contrast MRI.

    PubMed

    Liu, Wei; Wang, Binquan; Wolfowitz, Rachel; Yeh, Ping-Hong; Nathan, Dominic E; Graner, John; Tang, Haiying; Pan, Hai; Harper, Jamie; Pham, Dzung; Oakes, Terrence R; French, Louis M; Riedy, Gerard

    2013-06-01

    Perfusion deficits in patients with mild traumatic brain injury (TBI) from a military population were characterized by dynamic susceptibility contrast perfusion imaging. Relative cerebral blood flow (rCBF) was calculated by a model-independent deconvolution approach from the tracer concentration curves following a bolus injection of gadolinium diethylenetriaminepentaacetate (Gd-DTPA) using both manually and automatically selected arterial input functions (AIFs). Linear regression analysis of the mean values of rCBF from selected regions of interest showed a very good agreement between the two approaches, with a regression coefficient of R = 0.88 and a slope of 0.88. The Bland-Altman plot also illustrated the good agreement between the two approaches, with a mean difference of 0.6 ± 12.4 mL/100 g/min. Voxelwise analysis of rCBF maps from both approaches demonstrated multiple clusters of decreased perfusion (p < 0.01) in the cerebellum, cuneus, cingulate and temporal gyrus in the group with mild TBI relative to the controls. MRI perfusion deficits in the cerebellum and anterior cingulate also correlated (p < 0.01) with neurocognitive results, including the mean reaction time in the Automated Neuropsychological Assessment Metrics and commission error and detection T-scores in the Continuous Performance Test, as well as neurobehavioral scores in the Post-traumatic Stress Disorder Checklist-Civilian Version. In conclusion, rCBF calculated using AIFs selected from an automated approach demonstrated a good agreement with the corresponding results using manually selected AIFs. Group analysis of patients with mild TBI from a military population demonstrated scattered perfusion deficits, which showed significant correlations with measures of verbal memory, speed of reaction time and self-report of stress symptoms. PMID:23456696

  6. Decreased Brain and Placental Perfusion in Omphalopagus Conjoined Twins on Fetal MRI.

    PubMed

    Gorkem, Sureyya Burcu; Kutuk, Mehmet Serdar; Doganay, Selim; Gunes, Tamer; Yildiz, Karamehmet; Kucukaydin, Mustafa

    2016-01-01

    The aim of this study is to evaluate perfusional changes in brain and placenta of omphalopagus conjoined twins and to compare them with singleton fetuses by using diffusion weighted imaging and apparent diffusion coefficient. Fetal MRIs of 28-week-old omphalopagus conjoined twins with a shared liver with two separate gallbladders and portal and hepatic venous systems and three singleton fetuses with unilateral borderline ventriculomegaly at the same gestational week as control group were enrolled retrospectively. There was a significant decrease in ADC values of brain regions (p = 0.018) and placenta (p = 0.005) of conjoined twins compared to the control group. The decreased ADC values in placenta and brain regions in conjoined twins might be due to decreased placental perfusion compared to singleton pregnancy. Our results would be a keystone for future studies which will compare larger group of monochorionic multiple pregnancies with singleton pregnancies. PMID:27034830

  7. Decreased Brain and Placental Perfusion in Omphalopagus Conjoined Twins on Fetal MRI

    PubMed Central

    Kutuk, Mehmet Serdar; Doganay, Selim; Gunes, Tamer; Yildiz, Karamehmet; Kucukaydin, Mustafa

    2016-01-01

    The aim of this study is to evaluate perfusional changes in brain and placenta of omphalopagus conjoined twins and to compare them with singleton fetuses by using diffusion weighted imaging and apparent diffusion coefficient. Fetal MRIs of 28-week-old omphalopagus conjoined twins with a shared liver with two separate gallbladders and portal and hepatic venous systems and three singleton fetuses with unilateral borderline ventriculomegaly at the same gestational week as control group were enrolled retrospectively. There was a significant decrease in ADC values of brain regions (p = 0.018) and placenta (p = 0.005) of conjoined twins compared to the control group. The decreased ADC values in placenta and brain regions in conjoined twins might be due to decreased placental perfusion compared to singleton pregnancy. Our results would be a keystone for future studies which will compare larger group of monochorionic multiple pregnancies with singleton pregnancies. PMID:27034830

  8. SPECT brain perfusion imaging with Tc-99m ECD: Semi-quantitative regional analysis and database mapping

    SciTech Connect

    Schiepers, C.; Hegge, J.; De Roo, M.

    1994-05-01

    Brain SPECT is a well accepted method for the assessment of brain perfusion in various disorders such as epilepsy, stroke, dementia. A program for handling the tomographic data was developed, using a commercial spreadsheet (Microsoft EXCEL) with a set of macro`s for analysis, graphic display and database management of the final results.

  9. Anger camera imaging of perfused and nonperfused brain tissue with intra-arterial 133Xenon technique.

    PubMed

    Guldberg, C; Karle, A; Jørgensen, P B

    1977-12-30

    The regional cerebral blood flow, the regional blood flow distribution, and the regional distribution of perfused (= vital) brain tissue been imaged with a digitalized conventional Anger camer. An analog scaler was placed behind the PM-tubes to reduce dead-time loss. The input pulse rate was doubled to counteract the effect of scaling on counting statistics, and the gamma emission was filtered through 1 mm of brass to increase the fraction of the integral count rate within the 40% window. In this way the 31 keV peak disappears, and Compton scatter and disturbing coincidences are markedly reduced. This improves spatial resolution. The flow parameters are imaged regionally in 3 X 3 mm2 matrix elements after flat field correction and smoothing. The matrix is 64 X 64 interpolated to 128 X 128. Patient studies emphasized the importance of imaging the distribution of perfused and nonperfused tissue in cases of infarctions, dilacerations, etc., where angiography and conventional brain scanning may often be negative. PMID:415863

  10. Current concepts of optimal cerebral perfusion pressure in traumatic brain injury

    PubMed Central

    Prabhakar, Hemanshu; Sandhu, Kavita; Bhagat, Hemant; Durga, Padmaja; Chawla, Rajiv

    2014-01-01

    Traumatic brain injury (TBI) consists of varied pathophysiological consequences and alteration of intracranial dynamics, reduction of the cerebral blood flow and oxygenation. In the past decade more emphasis has been directed towards optimizing cerebral perfusion pressure (CPP) in patients who have suffered TBI. Injured brain may show signs of ischemia if CPP remains below 50 mmHg and raising the CPP above 60 mmHg may avoid cerebral oxygen desaturation. Though CPP above 70 mmHg is influential in achieving an improved patient outcome, maintenance of CPP higher than 70 mmHg was associated with greater risk of acute respiratory distress syndrome (ARDS). The target CPP has been laid within 50-70 mmHg. Cerebral blood flow and metabolism are heterogeneous after TBI and with regional temporal differences in the requirement for CPP. Brain monitoring techniques such as jugular venous oximetry, monitoring of brain tissue oxygen tension (PbrO2), and cerebral microdialysis provide complementary and specific information that permits the selection of the optimal CPP. This review highlights the rationale for use CPP directed therapies and neuromonitoring to identify optimal CPP of head injured patients. The article also reviews the evidence provided by various clinical trials regarding optimal CPP and their application in the management of head injured patients. PMID:25190937

  11. Stroke prognosis by applying double thresholds on CT-perfusion-brain images

    NASA Astrophysics Data System (ADS)

    Chokchaitam, Somchart; Santipromwong, Nittaya; Muengtaweepongsa, Sombat

    2013-03-01

    The CT-perfusion image shows information of brain abnormalities such as its size and location. Generally, neurologist diagnoses stroke disease using CT-perfusion images such as Cerebral blood flow (CBF), cerebral blood volume (CBV). In our previous report, we applied threshold technique to divide amount of CBV and CBF into low and high level. Then, their levels are applied to identify normal tissue areas, dead tissue areas (infract core) and blood-cot tissue areas (infract penumbra). However, it's not totally correct, if the same threshold is applied to the whole area (it must depend on size of blood vessel in that area. In this report, we propose double thresholds to divided CBV and CBF into 3 levels: very low, medium and very high levels. Very low and very high levels are definitely implied to bad areas and good areas, respectively. The proposed double thresholds makes stroke prognosis more accurate. The simulation results confirm that our proposed results closed to results defined from neurologist comparing to the conventional results.

  12. Arterial Spin Labeling Perfusion Study in the Patients with Subacute Mild Traumatic Brain Injury

    PubMed Central

    Lin, Che-Ming; Tseng, Ying-Chi; Hsu, Hui-Ling; Chen, Chi-Jen; Chen, David Yen-Ting; Yan, Feng-Xian; Chiu, Wen-Ta

    2016-01-01

    Background This study uses a MRI technique, three-dimension pulse continuous arterial spin labeling (3D-PCASL), to measure the patient’s cerebral blood flow (CBF) at the subacute stage of mild traumatic brain injury (MTBI) in order to analyze the relationship between cerebral blood flow and neurocognitive deficits. Objective To provide the relationship between cortical CBF and neuropsychological dysfunction for the subacute MTBI patients. Methods After MTBI, perfusion MR imaging technique (3D-PCASL) measures the CBF of MTBI patients (n = 23) within 1 month and that of normal controls (n = 22) to determine the quantity and location of perfusion defect. The correlation between CBF abnormalities and cognitive deficits was elucidated by combining the results of the neuropsychological tests of the patients. Result We observed a substantial reduction in CBF in the bilateral frontal and left occipital cortex as compared with the normal persons. In addition, there were correlation between post concussive symptoms (including dizziness and simulator sickness) and CBF in the hypoperfused areas. The more severe symptom was correlated with higher CBF in bilateral frontal and left occipital lobes. Conclusion First, this study determined that despite no significant abnormality detected on conventional CT and MRI studies, hypoperfusion was observed in MTBI group using 3D-PCASL technique in subacute stage, which suggested that this approach may increase sensitivity to MTBI. Second, the correlation between CBF and the severity of post concussive symptoms suggested that changes in cerebral hemodynamics may play a role in pathophysiology underlies the symptoms. PMID:26871696

  13. Baseline brain perfusion and brain structure in patients with major depression: a multimodal magnetic resonance imaging study

    PubMed Central

    Vasic, Nenad; Wolf, Nadine D.; Grön, Georg; Sosic-Vasic, Zrinka; Connemann, Bernhard J.; Sambataro, Fabio; von Strombeck, Anna; Lang, Dirk; Otte, Stefanie; Dudek, Manuela; Wolf, Robert C.

    2015-01-01

    Background Abnormal regional cerebral blood flow (rCBF) and grey matter volume have been frequently reported in patients with major depressive disorder (MDD). However, it is unclear to what extent structural and functional change co-occurs in patients with MDD and whether markers of neural activity, such as rCBF, can be predicted by structural change. Methods Using MRI, we investigated resting-state rCBF and brain structure in patients with MDD and healthy controls between July 2008 and January 2013. We acquired perfusion images obtained with continuous arterial spin labelling, used voxel-based morphometry to assess grey matter volume and integrated biological parametric mapping analyses to investigate the impact of brain atrophy on rCBF. Results We included 43 patients and 29 controls in our study. Frontotemporal grey matter volume was reduced in patients compared with controls. In patients, rCBF was reduced in the anterior cingulate and bilateral parahippocampal areas and increased in frontoparietal and striatal regions. These abnormalities were confirmed by analyses with brain volume as a covariate. In patients with MDD there were significant negative correlations between the extent of depressive symptoms and bilateral parahippocampal rCBF. We found a positive correlation between depressive symptoms and rCBF for right middle frontal cortical blood flow. Limitations Medication use in patients has to be considered as a limitation of our study. Conclusion Our data suggest that while changes of cerebral blood flow and brain volume co-occur in patients with MDD, structural change is not sufficient to explain altered neural activity in patients at rest. Abnormal brain structure and function in patients with MDD appear to reflect distinct levels of neuropathology. PMID:26125119

  14. Synthesis and evaluation of p-iodophentermine (IP) as a brain perfusion imaging agent

    SciTech Connect

    Elmaleh, D.R.; Kizuka, H.; Garneau, J.; Brownell, G.L.; Keiss, M.; B-Kovach, M.; Hanson, R.N.; Strauss, H.W.

    1984-01-01

    Recently N-isopropyl-rho-(/sup 123/I)-iodoamphetamine (IMP) has been reported as a potential cerebral perfusion imaging agent for single-photon emission tomography (SPECT). Since addition of a methyl group in the alpha position of amphetamine results in increased lipophilicity and prolonged residence time of the compound in the brain, the authors synthesized and evaluated the biological behaviour of rho-Iodo phenteramine (IP). IP was prepared by diazotization of rho-aminophentermine followed by decomposition of the diazonium salt with KI. Radioiodinated analog was prepared either by the solid-phase isotopic exchange reaction of Mangner et al or by decomposition of the piperidinotrazine derivative with a radiochemical yield of 40-60%. Biodistribution in rats showed that the brain concentration of /sup 131/I-IP was 1.69 +- 0.53, 1.70 +- 0.23 and 1.72 +- 0.11% injected dose/g tissue at 5, 30 and 60 min respectively, after IV injection. The lung uptake was 10.82% ID/g at 5 min and decreased to 7.7% ID/g at 60 min. The thyroid activity was low during the first hour of the study indicating minimal deiodination on the aryl ring. Sequential images of the brains of three dogs after intracarotid injection of /sup 123/I-IP showed localization of activity to one hemisphere of the brain, and clearance of <15% at one hour. In addition, SPECT images revealed more intense localization in the region of gray matter then white matter in the brain.

  15. Partial volume correction of brain perfusion estimates using the inherent signal data of time-resolved arterial spin labeling.

    PubMed

    Ahlgren, André; Wirestam, Ronnie; Petersen, Esben Thade; Ståhlberg, Freddy; Knutsson, Linda

    2014-09-01

    Quantitative perfusion MRI based on arterial spin labeling (ASL) is hampered by partial volume effects (PVEs), arising due to voxel signal cross-contamination between different compartments. To address this issue, several partial volume correction (PVC) methods have been presented. Most previous methods rely on segmentation of a high-resolution T1 -weighted morphological image volume that is coregistered to the low-resolution ASL data, making the result sensitive to errors in the segmentation and coregistration. In this work, we present a methodology for partial volume estimation and correction, using only low-resolution ASL data acquired with the QUASAR sequence. The methodology consists of a T1 -based segmentation method, with no spatial priors, and a modified PVC method based on linear regression. The presented approach thus avoids prior assumptions about the spatial distribution of brain compartments, while also avoiding coregistration between different image volumes. Simulations based on a digital phantom as well as in vivo measurements in 10 volunteers were used to assess the performance of the proposed segmentation approach. The simulation results indicated that QUASAR data can be used for robust partial volume estimation, and this was confirmed by the in vivo experiments. The proposed PVC method yielded probable perfusion maps, comparable to a reference method based on segmentation of a high-resolution morphological scan. Corrected gray matter (GM) perfusion was 47% higher than uncorrected values, suggesting a significant amount of PVEs in the data. Whereas the reference method failed to completely eliminate the dependence of perfusion estimates on the volume fraction, the novel approach produced GM perfusion values independent of GM volume fraction. The intra-subject coefficient of variation of corrected perfusion values was lowest for the proposed PVC method. As shown in this work, low-resolution partial volume estimation in connection with ASL perfusion

  16. Comparison of Perfusion- and Diffusion-weighted Imaging Parameters in Brain Tumor Studies Processed Using Different Software Platforms

    PubMed Central

    Milchenko, Mikhail V.; Rajderkar, Dhanashree; LaMontagne, Pamela; Massoumzadeh, Parinaz; Bogdasarian, Ronald; Schweitzer, Gordon; Benzinger, Tammie; Marcus, Dan; Shimony, Joshua S.; Fouke, Sarah Jost

    2015-01-01

    Rationale and Objectives To compare quantitative imaging parameter measures from diffusion- and perfusion-weighted imaging magnetic resonance imaging (MRI) sequences in subjects with brain tumors that have been processed with different software platforms. Materials and Methods Scans from 20 subjects with primary brain tumors were selected from the Comprehensive Neuro-oncology Data Repository at Washington University School of Medicine (WUSM) and the Swedish Neuroscience Institute. MR images were coregistered, and each subject's data set was processed by three software packages: 1) vendor-specific scanner software, 2) research software developed at WUSM, and 3) a commercially available, Food and Drug Administration–approved, processing platform (Nordic Ice). Regions of interest (ROIs) were chosen within the brain tumor and normal nontumor tissue. The results obtained using these methods were compared. Results For diffusion parameters, including mean diffusivity and fractional anisotropy, concordance was high when comparing different processing methods. For perfusion-imaging parameters, a significant variance in cerebral blood volume, cerebral blood flow, and mean transit time (MTT) values was seen when comparing the same raw data processed using different software platforms. Correlation was better with larger ROIs (radii ≥ 5 mm). Greatest variance was observed in MTT. Conclusions Diffusion parameter values were consistent across different software processing platforms. Perfusion parameter values were more variable and were influenced by the software used. Variation in the MTT was especially large suggesting that MTT estimation may be unreliable in tumor tissues using current MRI perfusion methods. PMID:25088833

  17. Detection of the brain response during a cognitive task using perfusion-based event-related functional MRI.

    PubMed

    Yee, S H; Liu, H L; Hou, J; Pu, Y; Fox, P T; Gao, J H

    2000-08-01

    Event-related (ER) fMRI has evoked great interest due to the ability to depict the dynamic features of human brain function during various cognitive tasks. Thus far, all cognitive ER-fMRI studies have been based on blood oxygenation level-dependent (BOLD) contrast techniques. Compared with BOLD-based fMRI techniques, perfusion-based fMRI is able to localize the region of neuronal activity more accurately. This report demonstrates, for the first time, the detection of the brain response to a cognitive task using high temporal resolution perfusion-based ER-fMRI. An English verb generation task was used in this study. Results show that perfusion-based ER-fMRI accurately depicts the activation in Broca's area. Average changes in regional relative cerebral blood flow reached a maximum value of 30.7% at approximately 6.5 s after the start of stimulation and returned to 10% of the maximum value at approximately 12.8 s. Our results show that perfusion-based ER-fMRI is a useful tool for cognitive neuroscience studies, providing comparable temporal resolution and better localization of brain function than BOLD ER-fMRI. PMID:10943717

  18. [Assessment of brain perfusion by arterial spin-labeling MR imaging in qusai-moyamoya disease associated with Graves' disease].

    PubMed

    Hayashi, Hisako; Kawatani, Masao; Ohta, Genrei; Kometani, Hiroshi; Ohshima, Yusei

    2014-07-01

    We report a case of 12-year-old girl with Graves' disease who had presented with deterioration in physical and scholastic performances since 10 years of age. She had an episode of atonic seizure and difficulty in speech. Brain MRI revealed formation of moyamoya vessels and a lesion suggestive of ischemic changes in the left frontal lobe. Because of uncontrollable thyrotoxicosis with anti-thyroid drug, she received a subtotal thyroidectomy. Two months later, she received a shunt operation between left superficial temporal artery and middle cerebral artery. The postoperative arterial spin-labeling MR imaging demonstrated an improvement of brain perfusion in left frontal lobe compared with the preoperative one, and provided comparable results of angiography and acetazolamide-challenged 150-gas PET. Thus, arterial spin-labeling MR imaging seems useful for follow-up evaluation of brain perfusion in qusai-moyamoya disease. PMID:25154228

  19. Localized Drug Application and Sub-Second Voltammetric Dopamine Release Measurements in a Brain Slice Perfusion Device

    PubMed Central

    2015-01-01

    The use of fast scan cyclic voltammetry (FSCV) to measure the release and uptake of dopamine (DA) as well as other biogenic molecules in viable brain tissue slices has gained popularity over the last 2 decades. Brain slices have the advantage of maintaining the functional three-dimensional architecture of the neuronal network while also allowing researchers to obtain multiple sets of measurements from a single animal. In this work, we describe a simple, easy-to-fabricate perfusion device designed to focally deliver pharmacological agents to brain slices. The device incorporates a microfluidic channel that runs under the perfusion bath and a microcapillary that supplies fluid from this channel up to the slice. We measured electrically evoked DA release in brain slices before and after the administration of two dopaminergic stimulants, cocaine and GBR-12909. Measurements were collected at two locations, one directly over and the other 500 μm away from the capillary opening. Using this approach, the controlled delivery of drugs to a confined region of the brain slice and the application of this chamber to FSCV measurements, were demonstrated. Moreover, the consumption of drugs was reduced to tens of microliters, which is thousands of times less than traditional perfusion methods. We expect that this simply fabricated device will be useful in providing spatially resolved delivery of drugs with minimum consumption for voltammetric and electrophysiological studies of a variety of biological tissues both in vitro and ex vivo. PMID:24734992

  20. Development of a realistic, dynamic digital brain phantom for CT perfusion validation

    NASA Astrophysics Data System (ADS)

    Divel, Sarah E.; Segars, W. Paul; Christensen, Soren; Wintermark, Max; Lansberg, Maarten G.; Pelc, Norbert J.

    2016-03-01

    Physicians rely on CT Perfusion (CTP) images and quantitative image data, including cerebral blood flow, cerebral blood volume, and bolus arrival delay, to diagnose and treat stroke patients. However, the quantification of these metrics may vary depending on the computational method used. Therefore, we have developed a dynamic and realistic digital brain phantom upon which CTP scans can be simulated based on a set of ground truth scenarios. Building upon the previously developed 4D extended cardiac-torso (XCAT) phantom containing a highly detailed brain model, this work consisted of expanding the intricate vasculature by semi-automatically segmenting existing MRA data and fitting nonuniform rational B-spline surfaces to the new vessels. Using time attenuation curves input by the user as reference, the contrast enhancement in the vessels changes dynamically. At each time point, the iodine concentration in the arteries and veins is calculated from the curves and the material composition of the blood changes to reflect the expected values. CatSim, a CT system simulator, generates simulated data sets of this dynamic digital phantom which can be further analyzed to validate CTP studies and post-processing methods. The development of this dynamic and realistic digital phantom provides a valuable resource with which current uncertainties and controversies surrounding the quantitative computations generated from CTP data can be examined and resolved.

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

    PubMed

    Xie, Long; Dolui, Sudipto; Das, Sandhitsu R; Stockbower, Grace E; Daffner, Molly; Rao, Hengyi; Yushkevich, Paul A; Detre, John A; Wolk, David A

    2016-01-01

    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. PMID:27222794

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

    PubMed Central

    Xie, Long; Dolui, Sudipto; Das, Sandhitsu R.; Stockbower, Grace E.; Daffner, Molly; Rao, Hengyi; Yushkevich, Paul A.; Detre, John A.; Wolk, David A.

    2016-01-01

    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. PMID:27222794

  3. Is the solitary dark neuron a manifestation of postmortem trauma to the brain inadequately fixed by perfusion?

    PubMed

    Cammermeyer, J

    1978-06-01

    Dark neurons, classified as solitary because of their sparse occurrence, were discerned in the transitional zones between gray and white matter in various species of laboratory animals fixed by perfusion. These neurons, histologically indistinguishable from dark neurons in immersion fixed material, tended to develop when the saline perfusion was delayed or slow, the amount of the Bouin fixative was excessive, or the autopsy was performed shortly after the perfusion. Under these conditions, the white matter manifested a softer consistency and a paler color than the gray matter. These observations suggest that, as the consequence of regional differences in intensity and speed of fixation, distortion during extraction of the brain may activate a stress force in the transitional zones where incompletely fixed neurons become affected and acquire an abnormal affinity for aniline dyes and silver. PMID:97249

  4. Absolute perfusion measurements and associated iodinated contrast agent time course in brain metastasis: a study for contrast-enhanced radiotherapy

    PubMed Central

    Obeid, Layal; Deman, Pierre; Tessier, Alexandre; Balosso, Jacques; Estève, François; Adam, Jean- François

    2014-01-01

    Contrast-enhanced radiotherapy is an innovative treatment that combines the selective accumulation of heavy elements in tumors with stereotactic irradiations using medium energy X-rays. The radiation dose enhancement depends on the absolute amount of iodine reached in the tumor and its time course. Quantitative, postinfusion iodine biodistribution and associated brain perfusion parameters were studied in human brain metastasis as key parameters for treatment feasibility and quality. Twelve patients received an intravenous bolus of iodinated contrast agent (CA) (40 mL, 4 mL/s), followed by a steady-state infusion (160 mL, 0.5 mL/s) to ensure stable intratumoral amounts of iodine during the treatment. Absolute iodine concentrations and quantitative perfusion maps were derived from 40 multislice dynamic computed tomography (CT) images of the brain. The postinfusion mean intratumoral iodine concentration (over 30 minutes) reached 1.94±0.12 mg/mL. Reasonable correlations were obtained between these concentrations and the permeability surface area product and the cerebral blood volume. To our knowledge, this is the first quantitative study of CA biodistribution versus time in brain metastasis. The study shows that suitable and stable amounts of iodine can be reached for contrast-enhanced radiotherapy. Moreover, the associated perfusion measurements provide useful information for the patient recruitment and management processes. PMID:24447951

  5. Hemodynamic Segmentation of Brain Perfusion Images with Delay and Dispersion Effects Using an Expectation-Maximization Algorithm

    PubMed Central

    Lu, Chia-Feng; Guo, Wan-Yuo; Chang, Feng-Chi; Huang, Shang-Ran; Chou, Yen-Chun; Wu, Yu-Te

    2013-01-01

    Automatic identification of various perfusion compartments from dynamic susceptibility contrast magnetic resonance brain images can assist in clinical diagnosis and treatment of cerebrovascular diseases. The principle of segmentation methods was based on the clustering of bolus transit-time profiles to discern areas of different tissues. However, the cerebrovascular diseases may result in a delayed and dispersed local perfusion and therefore alter the hemodynamic signal profiles. Assessing the accuracy of the segmentation technique under delayed/dispersed circumstance is critical to accurately evaluate the severity of the vascular disease. In this study, we improved the segmentation method of expectation-maximization algorithm by using the results of hierarchical clustering on whitened perfusion data as initial parameters for a mixture of multivariate Gaussians model. In addition, Monte Carlo simulations were conducted to evaluate the performance of proposed method under different levels of delay, dispersion, and noise of signal profiles in tissue segmentation. The proposed method was used to classify brain tissue types using perfusion data from five normal participants, a patient with unilateral stenosis of the internal carotid artery, and a patient with moyamoya disease. Our results showed that the normal, delayed or dispersed hemodynamics can be well differentiated for patients, and therefore the local arterial input function for impaired tissues can be recognized to minimize the error when estimating the cerebral blood flow. Furthermore, the tissue in the risk of infarct and the tissue with or without the complementary blood supply from the communicating arteries can be identified. PMID:23894386

  6. Correlation of oxygenation and perfusion sensitive MRI with invasive micro probe measurements in healthy mice brain.

    PubMed

    Sedlacik, Jan; Reitz, Matthias; Bolar, Divya S; Adalsteinsson, Elfar; Schmidt, Nils O; Fiehler, Jens

    2015-03-01

    The non-invasive assessment of (patho-)physiological parameters such as, perfusion and oxygenation, is of great importance for the characterization of pathologies e.g., tumors, which may be helpful to better predict treatment response and potential outcome. To better understand the influence of physiological parameters on the investigated oxygenation and perfusion sensitive MRI methods, MRI measurements were correlated with subsequent invasive micro probe measurements during free breathing conditions of air, air+10% CO2 and 100% O2 in healthy mice brain. MRI parameters were the irreversible (R2), reversible (R2') and effective (R2*) transverse relaxation rates, venous blood oxygenation level assessed by quantitative blood oxygenation level dependent (qBOLD) method and cerebral blood flow (CBF) assessed by arterial spin labeling (ASL) using a 7 T small animal MRI scanner. One to two days after MRI, tissue perfusion and pO2 were measured by Laser-Doppler flowmetry and fluorescence quenching micro probes, respectively. The tissue pO2 values were converted to blood oxygen saturation by using the Hill equation. The animals were anesthetized by intra peritoneal injection of ketamine-xylazine-acepromazine (10-2-0.3 mg/ml · kg). Results for normal/hypercapnia/hyperoxia conditions were: R2[s(∧)-1] = 20.7/20.4/20.1, R2*[s(∧)-1] = 31.6/29.6/25.9, R2'[s-(∧)1] = 10.9/9.2/5.7, qBOLD venous blood oxygenation level = 0.43/0.51/0.56, CBF[ml · min(∧)-1 · 100 g(∧)-1] = 70.6/105.5/81.8, Laser-Doppler flowmetry[a.u.] = 89.2/120.2/90.6 and pO2[mmHg] = 6.3/32.3/46.7. All parameters were statistically significantly different with P < 0.001 between all breathing conditions. All MRI and the corresponding micro probe measurements were also statistically significantly (P ≤ 0.03) correlated with each other. However, converting the tissue pO2 to blood oxygen saturation = 0.02/0.34/0.63, showed only very limited agreement with the qBOLD venous blood oxygenation level. We found

  7. Mismatch between iodine-123 IMP and technetium-99m HM-PAO brain perfusion imaging in a patient with meningioma

    SciTech Connect

    Hoshi, H.; Jinnouchi, S.; Watanabe, K.; Nakano, S.; Kinoshita, K.

    1987-09-01

    The discrepancy between three methods for cerebral perfusion imagings in the case of a man with meningioma is presented. Imaging with N-isopropyl-P-(I-123) iodoamphetamine (IMP) showed no activity in the tumor. Imaging with Tc-99m hexamethylpropyleneamine oxime (HM-PAO) and the local cerebral blood flow (LCBF) image with Xe-133 inhalation showed high tumor activity. IMP is a more accurate method for imaging the brain tissue blood flow.

  8. SPECT Perfusion Imaging Demonstrates Improvement of Traumatic Brain Injury With Transcranial Near-infrared Laser Phototherapy.

    PubMed

    Henderson, Theodore A; Morries, Larry D

    2015-01-01

    Traumatic brain injury (TBI) is a growing health concern affecting civilians and military personnel. Near-infrared (NIR) light has shown benefits in animal models and human trials for stroke and in animal models for TBI. Diodes emitting low-level NIR often have lacked therapeutic efficacy, perhaps failing to deliver sufficient radiant energy to the necessary depth. In this case report, a patient with moderate TBI documented in anatomical magnetic resonance imaging (MRI) and perfusion single-photon emission computed tomography (SPECT) received 20 NIR treatments in the course of 2 mo using a high-power NIR laser. Symptoms were monitored by clinical examination and a novel patient diary system specifically designed for this patient population. Clinical application of these levels of infrared energy for this patient with TBI yielded highly favorable outcomes with decreased depression, anxiety, headache, and insomnia, whereas cognition and quality of life improved. Neurological function appeared to improve based on changes in the SPECT by quantitative analysis. NIR in the power range of 10-15 W at 810 and 980 nm can safely and effectively treat chronic symptoms of TBI. PMID:26535475

  9. Reduction in radiation dose with reconstruction technique in the brain perfusion CT

    NASA Astrophysics Data System (ADS)

    Kim, H. J.; Lee, H. K.; Song, H.; Ju, M. S.; Dong, K. R.; Chung, W. K.; Cho, M. S.; Cho, J. H.

    2011-12-01

    The principal objective of this study was to verify the utility of the reconstruction imaging technique in the brain perfusion computed tomography (PCT) scan by assessing reductions in the radiation dose and analyzing the generated images. The setting used for image acquisition had a detector coverage of 40 mm, a helical thickness of 0.625 mm, a helical shuttle mode scan type and a rotation time of 0.5 s as the image parameters used for the brain PCT scan. Additionally, a phantom experiment and an animal experiment were carried out. In the phantom and animal experiments, noise was measured in the scanning with the tube voltage fixed at 80 kVp (kilovolt peak) and the level of the adaptive statistical iterative reconstruction (ASIR) was changed from 0% to 100% at 10% intervals. The standard deviation of the CT coefficient was measured three times to calculate the mean value. In the phantom and animal experiments, the absorbed dose was measured 10 times under the same conditions as the ones for noise measurement before the mean value was calculated. In the animal experiment, pencil-type and CT-dedicated ionization chambers were inserted into the central portion of pig heads for measurement. In the phantom study, as the level of the ASIR changed from 0% to 100% under identical scanning conditions, the noise value and dose were proportionally reduced. In our animal experiment, the noise value was lowest when the ASIR level was 50%, unlike in the phantom study. The dose was reduced as in the phantom study.

  10. Evaluating the feasibility of C-arm CT for brain perfusion imaging: an in vitro study

    NASA Astrophysics Data System (ADS)

    Ganguly, A.; Fieselmann, A.; Boese, J.; Rohkohl, C.; Hornegger, J.; Fahrig, R.

    2010-02-01

    C-arm cone-beam CT (CBCT) is increasingly being used to supplement 2D real-time data with 3D information. Temporal resolution is currently limited by the mechanical rotation speed of the C-arm which presents challenges for applications such as imaging of contrast flow in brain perfusion CT (PCT). We present a novel scheme where multiple scans are obtained at different start times with respect to the contrast injection. The data is interleaved temporally and interpolated during 3D reconstruction. For evaluation we developed a phantom to generate the range of temporal frequencies relevant for PCT. The highest requirements are for imaging the arterial input function (AIF) modeled as a gamma-variate function. Fourier transform analysis of the AIF showed that 90% of the spectral energy is contained at frequencies lower than 0.08Hz. We built an acrylic cylinder phantom of diameter 1.9 cm, with 25 sections of 1cm length each. Iodine concentration in each compartment was varied to produce a half-cycle sinusoid variation in HU in version 1, and 2.5 cycles in version 2 of the phantom. The phantom was moved linearly at speeds from 0.5cm/s to 4cm/s (temporal frequencies of 0.02Hz to 0.09Hz) and imaged using a C-arm system. Phantom CT numbers in a slice reconstructed at isocenter were measured and sinusoidal fits to the data were obtained. The fitted sinusoids had frequencies that were within 3+/-2% of the actual temporal frequencies of the sinusoid. This suggests that the imaging and reconstruction scheme is adequate for PCT imaging.

  11. Comparison of Partial Volume Effects in Arterial and Venous Contrast Curves in CT Brain Perfusion Imaging

    PubMed Central

    Riordan, Alan J.; Bennink, Edwin; Dankbaar, Jan Willem; Viergever, Max A.; Velthuis, Birgitta K.; Smit, Ewoud J.; de Jong, Hugo W. A. M.

    2014-01-01

    Purpose In brain CT perfusion (CTP), the arterial contrast bolus is scaled to have the same area under the curve (AUC) as the venous outflow to correct for partial volume effects (PVE). This scaling is based on the assumption that large veins are unaffected by PVE. Measurement of the internal carotid artery (ICA), usually unaffected by PVE due to its large diameter, may avoid the need for partial volume correction. The aims of this work are to examine i) the assumptions behind PVE correction and ii) the potential of selecting the ICA obviating correction for PVE. Methods The AUC of the ICA and sagittal sinus were measured in CTP datasets from 52 patients. The AUCs were determined by i) using commercial CTP software based on a Gaussian curve-fitting to the time attenuation curve, and ii) by simple integration of the time attenuation curve over a time interval. In addition, frames acquired up to 3 minutes after first bolus passage were used to examine the ratio of arterial and venous enhancement. The impact of selecting the ICA without PVE correction was illustrated by reporting cerebral blood volume (CBV) measurements. Results In 49 of 52 patients, the AUC of the ICA was significantly larger than that of the sagittal sinus (p = 0.017). Measured after the first pass bolus, contrast enhancement remained 50% higher in the ICA just after the first pass bolus, and 30% higher 3 minutes later. CBV measurements were significantly lowered when the ICA was used without PVE correction. Conclusions Contradicting the assumptions underlying PVE correction, contrast in the ICA was significantly higher than in the sagittal sinus, even 3 minutes after the first pass of the contrast bolus. PVE correction might lead to overestimation of CBV if the CBV is calculated using the AUC of the time attenuation curves. PMID:24858308

  12. An a contrario approach for the detection of patient-specific brain perfusion abnormalities with arterial spin labelling.

    PubMed

    Maumet, Camille; Maurel, Pierre; Ferré, Jean-Christophe; Barillot, Christian

    2016-07-01

    In this paper, we introduce a new locally multivariate procedure to quantitatively extract voxel-wise patterns of abnormal perfusion in individual patients. This a contrario approach uses a multivariate metric from the computer vision community that is suitable to detect abnormalities even in the presence of closeby hypo- and hyper-perfusions. This method takes into account local information without applying Gaussian smoothing to the data. Furthermore, to improve on the standard a contrario approach, which assumes white noise, we introduce an updated a contrario approach that takes into account the spatial coherency of the noise in the probability estimation. Validation is undertaken on a dataset of 25 patients diagnosed with brain tumours and 61 healthy volunteers. We show how the a contrario approach outperforms the massively univariate general linear model usually employed for this type of analysis. PMID:27039702

  13. A non-linear regression method for CT brain perfusion analysis

    NASA Astrophysics Data System (ADS)

    Bennink, E.; Oosterbroek, J.; Viergever, M. A.; Velthuis, B. K.; de Jong, H. W. A. M.

    2015-03-01

    CT perfusion (CTP) imaging allows for rapid diagnosis of ischemic stroke. Generation of perfusion maps from CTP data usually involves deconvolution algorithms providing estimates for the impulse response function in the tissue. We propose the use of a fast non-linear regression (NLR) method that we postulate has similar performance to the current academic state-of-art method (bSVD), but that has some important advantages, including the estimation of vascular permeability, improved robustness to tracer-delay, and very few tuning parameters, that are all important in stroke assessment. The aim of this study is to evaluate the fast NLR method against bSVD and a commercial clinical state-of-art method. The three methods were tested against a published digital perfusion phantom earlier used to illustrate the superiority of bSVD. In addition, the NLR and clinical methods were also tested against bSVD on 20 clinical scans. Pearson correlation coefficients were calculated for each of the tested methods. All three methods showed high correlation coefficients (>0.9) with the ground truth in the phantom. With respect to the clinical scans, the NLR perfusion maps showed higher correlation with bSVD than the perfusion maps from the clinical method. Furthermore, the perfusion maps showed that the fast NLR estimates are robust to tracer-delay. In conclusion, the proposed fast NLR method provides a simple and flexible way of estimating perfusion parameters from CT perfusion scans, with high correlation coefficients. This suggests that it could be a better alternative to the current clinical and academic state-of-art methods.

  14. CT-perfusion imaging of the human brain: advanced deconvolution analysis using circulant singular value decomposition.

    PubMed

    Wittsack, H J; Wohlschläger, A M; Ritzl, E K; Kleiser, R; Cohnen, M; Seitz, R J; Mödder, U

    2008-01-01

    According to indicator dilution theory tissue time-concentration curves have to be deconvolved with arterial input curves in order to get valid perfusion results. Our aim was to adapt and validate a deconvolution method originating from magnetic resonance techniques and apply it to the calculation of dynamic contrast enhanced computed tomography perfusion imaging. The application of a block-circulant matrix approach for singular value decomposition renders the analysis independent of tracer arrival time to improve the results. PMID:18029143

  15. Differences in Cerebral Perfusion Deficits in Mild Traumatic Brain Injury and Depression Using Single-Photon Emission Computed Tomography

    PubMed Central

    Romero, Kristoffer; Black, Sandra E.; Feinstein, Anthony

    2014-01-01

    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 (MDD), but no TBI were given 99m T-ECD single-photon emission computed tomography (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 compared to both TBI groups 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. Conclusion: 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. PMID:25191305

  16. [Brain MR perfusion and MR spectroscopy in differentiation of radiation necrosis from tumor recurrence (case report)].

    PubMed

    Tekşam, Mehmet; Kayahan, Esra Meltem; Yerli, Hasan; Ağildere, A Muhteşem

    2004-12-01

    It is not always possible to differentiate tumor recurrence from radiation necrosis using conventional MR images. In this report we present a case of pathologically proven radiation necrosis which appeared as nodular contrast enhancement on conventional MR images in a patient who was surgically treated for grade II astrocytoma 5 years ago. There were decreased choline, creatine and N-acetyl aspartate peaks and significantly increased lipid peak on multivoxel H1-MR spectroscopy while there was no significant perfusion increase on MR perfusion. These findings suggested changes secondary to radiation necrosis. PMID:15611913

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Optical monitoring of cardiac and respiratory rhythms in the skin perfusion near the brain under controlled conditions

    NASA Astrophysics Data System (ADS)

    Mukunda Rao, M.; Blazek, Vladimir; Schmitt, Hans J.

    1998-06-01

    In this investigation an attempt is made to find the effects of controlled breathing on brain with the help of optical sensors mounted on the left and right temples of a subject. It has already been established that the brain activity can be monitored in terms of arterial blood volumetric changes to the left and right hemispheres of the brain recorded with the help of optical sensors. To investigate the influence of controlled breathing, an expert in controlled breathing (pranayama) is chosen as the subject. Pranayama is believed to be the controlled intake and outflow of breath in a firmly established posture. Some types of pranayama are believed to relive mental stress. While the subject is practicing one such type of breath control, arterial blood volume changes in the brain are recorded using optical sensors mounted on the left and right temples of the subject. From these measurements at the beginning and end of the pranayama exercise, it could be noticed that the subject could induce changes in the cardiac and respiratory rhythms by controlled breathing. Rhythmic phenomena in the skin perfusion in the vicinity of the brian are also studied when the subject is holding his breath. The arterial blood volume changes to the left and right hemispheres of the brain, as monitored by the optical sensors during this period, exhibit asymmetric reaction when the subject is holding his breath. An attempt is made to understand whether these changes induced by stoppage of breathing are 'chaotic' or 'adaptive' in nature.

  19. Changes of Cerebral Perfusion and Functional Brain Network Organization in Patients with Mild Cognitive Impairment.

    PubMed

    Lou, Wutao; Shi, Lin; Wong, Adrian; Chu, Winnie C W; Mok, Vincent C T; Wang, Defeng

    2016-08-10

    Disruptions of the functional brain network and cerebral blood flow (CBF) have been revealed in patients with mild cognitive impairment (MCI). However, the neurophysiological mechanism of hypoperfusion as well as the reorganization of the intrinsic whole brain network due to the neuropathology of MCI are still unclear. In this study, we aimed to investigate the changes of CBF and the whole brain network organization in MCI by using a multimodal MRI approach. Resting state ASL MRI and BOLD MRI were used to evaluate disruptions of CBF and underlying functional connectivity in 27 patients with MCI and 35 cognitive normal controls (NC). The eigenvector centrality mapping (ECM) was used to assess the whole brain network reorganization in MCI, and a seed-based ECM approach was proposed to reveal the contributions of the whole brain network on the ECM alterations. Significantly decreased perfusion in the posterior parietal cortex as well as its connectivity within the default mode network and occipital cortex were found in the MCI group compared to the NC group. The ECM analysis revealed decreased EC in the middle cingulate cortex, parahippocampal gyrus, medial frontal gyrus, and increased EC in the right calcarine sulcus, superior temporal gyrus, and supplementary motor area in the MCI group. The results of this study indicate that there are deficits in cerebral blood flow and functional connectivity in the default mode network, and that sensory-processing networks might play a compensatory role to make up for the decreased connections in MCI. PMID:27567823

  20. Optical monitoring of cardiac and respiratory rhythms in the skin perfusion near the brain under controlled conditions

    NASA Astrophysics Data System (ADS)

    Mukunda Rao, M.; Blazek, Vladimir; Schmitt, Hans J.

    1998-04-01

    In this investigation an attempt is made to find the effects of controlled breathing on brain with the help of optical sensor mounted on the left and right temples of a subject. It has already been established that the brain activity can be monitored in terms of arterial blood volumetric changes to the left and right hemispheres of the brain recorded with the help of optical sensors. To investigate the influence of controlled breathing, an expert in controlled breathing is chosen as the subject. Pranayama is believed to be the controlled intake and outflow of breath in a firmly established posture. Some types of pranayama are believed to relieve mental stress. While the subject is practicing one such type of breath control, arterial blood volume changes in the brain are recorded using optical sensor mounted on the left and right temples of the subject. From these measurements at the beginning and end of the pranayama exercise, it could be noticed that the subject could induce changes in the cardiac and respiratory rhythms by controlled breathing. Rhythmic phenomena in the skin perfusion in the vicinity of the brian are also studied when the subject is holding his breath. The arterial blood volume changes to the left and right hemispheres of the brian, as monitored by the optical sensors during this period, exhibit asymmetric reaction when the subject is holding his breath. An attempt is made to understand whether these changes induced by stoppage of breathing are 'chaotic' or 'adaptive' in nature.

  1. Estimation of brain perfusion using Va value as initial distribution volume in radionuclide angiography with technetium-99m HMPAO

    SciTech Connect

    Kawamoto, M.; Ikegami, T.

    1994-05-01

    Matsuda reported a non-invasive, simple method for the quantitative measurements of brain perfusion using radionuclide angiography with Tc-99m. HMPAO and showed graphical analysis of the ratio of brain activity to aortic arch activity gave two parameters, which are the slope of the fitted line (Ku:unidirectional influx constant) and its intercept with the yards (Vn:initial volume of distribution). Brain perfusion index (BPI),which is a connected Ku value, showed good correlation with cerebral blood flow determined with Xe-133 SPECT. The aim of our study is to elucidate the clinical significance of another parameter, Vn value, determined inpatients with cerebral vessel disease. Eighty-nine cases were studied and classified into three groups on the basis of clinical history and images of CT and/or MR: Group A, normal, 36 cases; Group B, infarction, 44 cases; Group C, subarachnoid hemorrhage, 9 cases. The average age of each group were not different statistically (63.3, 67.4 and 59.8, respectively). The average BPI values for group B and C were significantly lower than that of group A(7.7, 6. 8 and 9.5, respectively ). On the other hand, Vn for group C(0.23) was significantly lower than that for group A(0.45); however that for group B(0.49) was not. These findings indicate that cerebral blood flow in both infarction and subarachnoid hemorrhage decrease but their circumstances near vessels differ from the aspect of initial volume of tracer distribution. This might help to understand or diagnose cerebral vessel diseases.

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

    PubMed

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

    2016-01-01

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

  3. Thirty minute transcutaneous electric acupoint stimulation modulates resting state brain activities: a perfusion and BOLD fMRI study.

    PubMed

    Jiang, Yin; Hao, Ying; Zhang, Yue; Liu, Jing; Wang, Xiaoying; Han, Jisheng; Fang, Jing; Zhang, Jue; Cui, Cailian

    2012-05-31

    Increasing neuroimaging studies have focused on the sustained after effects of acupuncture, especially for the changes of brain activities in rest. However, short-period stimuli have mostly been chosen in these works. The present study aimed to investigate how the resting state brain activities in healthy subjects were modulated by relatively long-period (30 min) acupuncture, a widely used modality in clinical practice. Transcutaneous electric acupoint stimulation (TEAS) or intermittent minimal TEAS (MTEAS) were given for 30 min to 40 subjects. Functional MRI (fMRI) data were collected including the pre-stimulation resting state and the post-stimulation resting state, using dual-echo arterial spin labeling (ASL) techniques, representing both cerebral blood flow (CBF) signals and blood oxygen-dependent level (BOLD) signals simultaneously. Following 30 min TEAS, but not MTEAS, the mean global CBF decreased, and a significant decrease of regional CBF was observed in SI, insula, STG, MOG and IFG. Functional connectivity analysis showed more secure and spatially extended connectivity of both the DMN and SMN after 30 min TEAS. Our results implied that modulation of the regional brain activities and network connectivity induced by thirty minute TEAS may associate with the acupuncture-related therapeutic effects. Furthermore, the resting state regional CBF quantified by ASL perfusion fMRI may serve as a potential biomarker in future acupuncture studies. PMID:22541167

  4. Technetium-99m bis (aminoethanethiol) complexes with amine sidechains--potential brain perfusion imaging agents for SPECT

    SciTech Connect

    Efange, S.M.; Kung, H.F.; Billings, J.; Guo, Y.Z.; Blau, M.

    1987-06-01

    In an effort to develop new clinically useful technetium-99m bis(aminoethanethiol) ((/sup 99m/Tc)BAT) complexes for the evaluation of regional cerebral perfusion, two new BAT ligands containing amines in the sidechain were synthesized and subsequently complexed with /sup 99m/Tc to yield the target complexes: (/sup 99m/Tc)DEA and (/sup 99m/Tc)TMPDA. Each complex was obtained as mixtures of two isomers, syn and anti, which were separated chromatographically. In biodistribution studies, both isomers of (/sup 99m/Tc)TMPDA showed little uptake in the brain. In contrast, the brain uptake values at 2 and 15 min for (/sup 99m/Tc)DEA-anti were 0.99 and 0.26, whereas, the corresponding values for DEA-syn were 2.27, 0.64% dose/organ, respectively. Autoradiographic studies (in rats) using both isomers of (/sup 99m/Tc)DEA show a fixed regional distribution and a higher concentration of radioactivity in the gray matter relative to the white matter. Planar imaging using (/sup 99m/Tc)DEA-syn clearly demonstrates localization of the complex in the brain with a T 1/2 of 41 min, suggesting some potential for use with single photon emission computed tomography.

  5. Early Cerebral Circulation Disturbance in Patients Suffering from Severe Traumatic Brain Injury (TBI): A Xenon CT and Perfusion CT Study

    PubMed Central

    HONDA, Mitsuru; ICHIBAYASHI, Ryo; YOKOMURO, Hiroki; YOSHIHARA, Katsunori; MASUDA, Hiroyuki; HAGA, Daisuke; SEIKI, Yoshikatsu; KUDOH, Chiaki; KISHI, Taichi

    2016-01-01

    Traumatic brain injury (TBI) is widely known to cause dynamic changes in cerebral blood flow (CBF). Ischemia is a common and deleterious secondary injury following TBI. Detecting early ischemia in TBI patients is important to prevent further advancement and deterioration of the brain tissue. The purpose of this study was to clarify the cerebral circulatory disturbance during the early phase and whether it can be used to predict patient outcome. A total of 90 patients with TBI underwent a xenon-computed tomography (Xe-CT) and subsequently perfusion CT to evaluate the cerebral circulation on days 1–3. We measured CBF using Xe-CT and mean transit time (MTT: the width between two inflection points [maximum upward slope and maximum downward slope from inflow to outflow of the contrast agent]) using perfusion CT and calculated the cerebral blood volume (CBV) using the AZ-7000W98 computer system. The relationships of the hemodynamic parameters CBF, MTT, and CBV to the Glasgow Coma Scale (GCS) score and the Glasgow Outcome Scale (GOS) score were examined. There were no significant differences in CBF, MTT, and CBV among GCS3–4, GCS5–6, and GCS7–8 groups. The patients with a favorable outcome (GR and MD) had significantly higher CBF and lower MTT than those with an unfavorable one (SD, VS, or D). The discriminant analysis of these parameters could predict patient outcome with a probability of 70.6%. During the early phase, CBF reduction and MTT prolongation might influence the clinical outcome of TBI. These parameters are helpful for evaluating the severity of cerebral circulatory disturbance and predicting the outcome of TBI patients. PMID:27356957

  6. Early Cerebral Circulation Disturbance in Patients Suffering from Severe Traumatic Brain Injury (TBI): A Xenon CT and Perfusion CT Study.

    PubMed

    Honda, Mitsuru; Ichibayashi, Ryo; Yokomuro, Hiroki; Yoshihara, Katsunori; Masuda, Hiroyuki; Haga, Daisuke; Seiki, Yoshikatsu; Kudoh, Chiaki; Kishi, Taichi

    2016-08-15

    Traumatic brain injury (TBI) is widely known to cause dynamic changes in cerebral blood flow (CBF). Ischemia is a common and deleterious secondary injury following TBI. Detecting early ischemia in TBI patients is important to prevent further advancement and deterioration of the brain tissue. The purpose of this study was to clarify the cerebral circulatory disturbance during the early phase and whether it can be used to predict patient outcome. A total of 90 patients with TBI underwent a xenon-computed tomography (Xe-CT) and subsequently perfusion CT to evaluate the cerebral circulation on days 1-3. We measured CBF using Xe-CT and mean transit time (MTT: the width between two inflection points [maximum upward slope and maximum downward slope from inflow to outflow of the contrast agent]) using perfusion CT and calculated the cerebral blood volume (CBV) using the AZ-7000W98 computer system. The relationships of the hemodynamic parameters CBF, MTT, and CBV to the Glasgow Coma Scale (GCS) score and the Glasgow Outcome Scale (GOS) score were examined. There were no significant differences in CBF, MTT, and CBV among GCS3-4, GCS5-6, and GCS7-8 groups. The patients with a favorable outcome (GR and MD) had significantly higher CBF and lower MTT than those with an unfavorable one (SD, VS, or D). The discriminant analysis of these parameters could predict patient outcome with a probability of 70.6%. During the early phase, CBF reduction and MTT prolongation might influence the clinical outcome of TBI. These parameters are helpful for evaluating the severity of cerebral circulatory disturbance and predicting the outcome of TBI patients. PMID:27356957

  7. Perfusion MRI Indexes Variability in the Functional Brain Effects of Theta-Burst Transcranial Magnetic Stimulation

    PubMed Central

    Gratton, Caterina; Lee, Taraz G.; Nomura, Emi M.; D’Esposito, Mark

    2014-01-01

    Transcranial Magnetic Stimulation (TMS) is an important tool for testing causal relationships in cognitive neuroscience research. However, the efficacy of TMS can be variable across individuals and difficult to measure. This variability is especially a challenge when TMS is applied to regions without well-characterized behavioral effects, such as in studies using TMS on multi-modal areas in intrinsic networks. Here, we examined whether perfusion fMRI recordings of Cerebral Blood Flow (CBF), a quantitative measure sensitive to slow functional changes, reliably index variability in the effects of stimulation. Twenty-seven participants each completed four combined TMS-fMRI sessions during which both resting state Blood Oxygen Level Dependent (BOLD) and perfusion Arterial Spin Labeling (ASL) scans were recorded. In each session after the first baseline day, continuous theta-burst TMS (TBS) was applied to one of three locations: left dorsolateral prefrontal cortex (L dlPFC), left anterior insula/frontal operculum (L aI/fO), or left primary somatosensory cortex (L S1). The two frontal targets are components of intrinsic networks and L S1 was used as an experimental control. CBF changes were measured both before and after TMS on each day from a series of interleaved resting state and perfusion scans. Although TBS led to weak selective increases under the coil in CBF measurements across the group, individual subjects showed wide variability in their responses. TBS-induced changes in rCBF were related to TBS-induced changes in functional connectivity of the relevant intrinsic networks measured during separate resting-state BOLD scans. This relationship was selective: CBF and functional connectivity of these networks were not related before TBS or after TBS to the experimental control region (S1). Furthermore, subject groups with different directions of CBF change after TBS showed distinct modulations in the functional interactions of targeted networks. These results suggest

  8. Near-Infrared Spectroscopy versus Magnetic Resonance Imaging To Study Brain Perfusion in Newborns with Hypoxic-Ischemic Encephalopathy Treated with Hypothermia

    PubMed Central

    Wintermark, P.; Hansen, A.; Warfield, SK.; Dukhovny, D.; Soul, JS.

    2014-01-01

    Background The measurement of brain perfusion may provide valuable information for assessment and treatment of newborns with hypoxic-ischemic encephalopathy (HIE). While arterial spin labeled perfusion (ASL) magnetic resonance imaging (MRI) provides noninvasive and direct measurements of regional cerebral blood flow (CBF) values, it is logistically challenging to obtain. Near-infrared spectroscopy (NIRS) might be an alternative, as it permits noninvasive and continuous monitoring of cerebral hemodynamics and oxygenation at the bedside. Objective The purpose of this study is to determine the correlation between measurements of brain perfusion by NIRS and by MRI in term newborns with HIE treated with hypothermia. Design/Methods In this prospective cohort study, ASL-MRI and NIRS performed during hypothermia were used to assess brain perfusion in these newborns. Regional cerebral blood flow values (CBF), measured from 1–2 MRI scans for each patient, were compared to mixed venous saturation values (SctO2) recorded by NIRS just before and after each MRI. Analysis included groupings into moderate versus severe HIE based on their initial background pattern of amplitude-integrated electroencephalogram. Results Twelve concomitant recordings were obtained of seven neonates. Strong correlation was found between SctO2 and CBF in asphyxiated newborns with severe HIE (r = 0.88; p value = 0.0085). Moreover, newborns with severe HIE had lower CBF (likely lower oxygen supply) and extracted less oxygen (likely lower oxygen demand or utilization) when comparing SctO2 and CBF to those with moderate HIE. Conclusions NIRS is an effective bedside tool to monitor and understand brain perfusion changes in term asphyxiated newborns, which in conjunction with precise measurements of CBF obtained by MRI at particular times, may help tailor neuroprotective strategies in term newborns with HIE. PMID:23631990

  9. Brain perfusion monitoring with frequency-domain and continuous-wave near-infrared spectroscopy: a cross-correlation study in newborn piglets

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Katz, A.; Alfano, R. R.; Kofinas, A. D.; Kofinas, D. A.; Stubblefield, P. G.; Rosenfeld, W.; Beyer, D.; Maulik, D.; Stankovic, M. R.

    2000-11-01

    The newborn piglet brain model was used to correlate continuous-wave (CW) and frequency-domain (FD) near-infrared spectroscopy. Six ventilated and instrumented newborn piglets were subjected to a series of manipulations in blood oxygenation with the effects on brain perfusion known to be associated with brain hypoxia-ischaemia. An excellent agreement between the CW and FD was demonstrated. This agreement improved when the scattering properties (determined by the FD device) were employed to calculate the differential pathlength factor, an important step in CW data processing.

  10. Penumbra Pattern Assessment in Acute Stroke Patients: Comparison of Quantitative and Non-Quantitative Methods in Whole Brain CT Perfusion

    PubMed Central

    Baumann, Alena B.; Meinel, Felix G.; Helck, Andreas D.; Opherk, Christian; Straube, Andreas; Reiser, Maximilian F.; Sommer, Wieland H.

    2014-01-01

    Background And Purpose While penumbra assessment has become an important part of the clinical decision making for acute stroke patients, there is a lack of studies measuring the reliability and reproducibility of defined assessment techniques in the clinical setting. Our aim was to determine reliability and reproducibility of different types of three-dimensional penumbra assessment methods in stroke patients who underwent whole brain CT perfusion imaging (WB-CTP). Materials And Methods We included 29 patients with a confirmed MCA infarction who underwent initial WB-CTP with a scan coverage of 100 mm in the z-axis. Two blinded and experienced readers assessed the flow-volume-mismatch twice and in two quantitative ways: Performing a volumetric mismatch analysis using OsiriX imaging software (MMVOL) and visual estimation of mismatch (MMEST). Complementarily, the semiquantitative Alberta Stroke Programme Early CT Score for CT perfusion was used to define mismatch (MMASPECTS). A favorable penumbral pattern was defined by a mismatch of ≥30% in combination with a cerebral blood flow deficit of ≤90 ml and an MMASPECTS score of ≥1, respectively. Inter- and intrareader agreement was determined by Kappa-values and ICCs. Results Overall, MMVOL showed considerably higher inter-/intrareader agreement (ICCs: 0.751/0.843) compared to MMEST (0.292/0.749). In the subgroup of large (≥50 mL) perfusion deficits, inter- and intrareader agreement of MMVOL was excellent (ICCs: 0.961/0.942), while MMEST interreader agreement was poor (0.415) and intrareader agreement was good (0.919). With respect to penumbra classification, MMVOL showed the highest agreement (interreader agreement: 25 agreements/4 non-agreements/κ: 0.595; intrareader agreement 27/2/0.833), followed by MMEST (22/7/0.471; 23/6/0.577), and MMASPECTS (18/11/0.133; 21/8/0.340). Conclusion The evaluated approach of volumetric mismatch assessment is superior to pure visual and ASPECTS penumbra pattern assessment in WB

  11. Octreoscan SPET evaluation in the diagnosis of pancreas neuroendocrine tumors.

    PubMed

    Briganti, V; Matteini, M; Ferri, P; Vaggelli, L; Castagnoli, A; Pieroni, C

    2001-12-01

    The study describes the results of Octreoscan SPET (OCTSPET) qualitative and semi-quantitative evaluation in 38 patients with suspected pancreatic neuroendocrine tumors. SPET studies were acquired at 4 and 24 hours after the injection of 111-220 MBq of 111-In-pentetreotide (Octreoscan). Qualitative and semi-quantitative evaluations were performed. The semi-quantitative approach was based on the time course of Tumor/Non Tumor ratios (TNTinc) from 4 and 24 hours. The OCTSPET results were true positive in 18 of 19 patients (10 gastrinoma, 5 insulinoma, 1 neuroendocrine tumor, 1 glucagonoma and 1 carcinoid) and false negative in one insulinoma. Besides, 20 of 38 patients (52%) had clinical plans modified after OCTSPET; OCTSPET was the only positive diagnostic test in 14 of 19 patients (73%) and guided the surgery decision in 14 of 25 patients (56%). In conclusion, these data indicate that Octreoscan represents an excellent tool for the diagnosis of pancreatic neuroendocrine tumors. PMID:11789028

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

    PubMed

    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

  13. 3D perfused brain phantom for interstitial ultrasound thermal therapy and imaging: design, construction and characterization

    NASA Astrophysics Data System (ADS)

    Martínez, José M.; Jarosz, Boguslaw J.

    2015-03-01

    Thermal therapy has emerged as an independent modality of treating some tumors. In many clinics the hyperthermia, one of the thermal therapy modalities, has been used adjuvant to radio- or chemotherapy to substantially improve the clinical treatment outcomes. In this work, a methodology for building a realistic brain phantom for interstitial ultrasound low dose-rate thermal therapy of the brain is proposed. A 3D brain phantom made of the tissue mimicking material (TMM) had the acoustic and thermal properties in the 20-32 °C range, which is similar to that of a brain at 37 °C. The phantom had 10-11% by mass of bovine gelatin powder dissolved in ethylene glycol. The TMM sonicated at 1 MHz, 1.6 MHz and 2.5 MHz yielded the amplitude attenuation coefficients of 62  ±  1 dB m-1, 115  ±  4 dB m-1 and 175  ±  9 dB m-1, respectively. The density and acoustic speed determination at room temperature (~24 °C) gave 1040  ±  40 kg m-3 and 1545  ±  44 m s-1, respectively. The average thermal conductivity was 0.532 W m-1 K-1. The T1 and T2 values of the TMM were 207  ±  4 and 36.2  ±  0.4 ms, respectively. We envisage the use of our phantom for treatment planning and for quality assurance in MRI based temperature determination. Our phantom preparation methodology may be readily extended to other thermal therapy technologies.

  14. CT-based attenuation and scatter correction compared with uniform attenuation correction in brain perfusion SPECT imaging for dementia

    NASA Astrophysics Data System (ADS)

    Gillen, Rebecca; Firbank, Michael J.; Lloyd, Jim; O'Brien, John T.

    2015-09-01

    This study investigated if the appearance and diagnostic accuracy of HMPAO brain perfusion SPECT images could be improved by using CT-based attenuation and scatter correction compared with the uniform attenuation correction method. A cohort of subjects who were clinically categorized as Alzheimer’s Disease (n=38 ), Dementia with Lewy Bodies (n=29 ) or healthy normal controls (n=30 ), underwent SPECT imaging with Tc-99m HMPAO and a separate CT scan. The SPECT images were processed using: (a) correction map derived from the subject’s CT scan or (b) the Chang uniform approximation for correction or (c) no attenuation correction. Images were visually inspected. The ratios between key regions of interest known to be affected or spared in each condition were calculated for each correction method, and the differences between these ratios were evaluated. The images produced using the different corrections were noted to be visually different. However, ROI analysis found similar statistically significant differences between control and dementia groups and between AD and DLB groups regardless of the correction map used. We did not identify an improvement in diagnostic accuracy in images which were corrected using CT-based attenuation and scatter correction, compared with those corrected using a uniform correction map.

  15. Evaluation of changes in the parameters of brain tissue perfusion in multi-slice computed tomography in patients after carotid artery stenting

    PubMed Central

    Szarmach, Arkadiusz; Halena, Grzegorz; Buczny, Jacek; Studniarek, Michał; Markiet, Karolina; Szurowska, Edyta; Retkowski, Mariusz; Piskunowicz, Maciej

    2011-01-01

    Summary Background: CT perfusion of the brain allows functional evaluation of cerebral blood flow. Patients with chronic internal carotid artery (ICA) stenosis may suffer from malperfusion. Improvement of cerebral blood flow and remission of neurological symptoms indicate the effectiveness of treatment of internal carotid artery stenosis. Material/Methods: The aim of the study was to analyze alterations within cerebral perfusion parameters in CT brain perfusion examination in patients who were scheduled for endovascular therapy due to ICA stenosis. Forty patients with ICA stenosis of over 79% who were included in this prospective study underwent perfusion CT examination twice – 24 hours prior to stenting and after 6–8 weeks following the procedure. CBF, CBV, MTT and TTP were evaluated. Results: Prior to endovascular therapy, an increase in MTT and TTP, and a decrease in CBV and CBF were observed within arterial supply of the hemisphere ipsilateral to stenosis. After the procedure, a decrease in MTT and TTP was seen in all cases, while no statistically significant changes of CBF or CBV were observed. MTT proved to be the most sensitive indicator of ICA stenosis, as its values allowed differentiation between critical and non-critical stenosis. No correlation between the degree of ICA stenosis and TTP values was found. Mild cerebral hyperperfusion syndrome (CHS) was observed in only one patient and the difference between pre-treatment MTT values calculated for both hemispheres was shown to be a prognostic factor for CHS incidence. Conclusions: Endovascular stent placing in patients with hemodynamically significant internal carotid artery stenosis results in alteration of perfusion parameters, especially concerning TTP and MTT. PMID:22802836

  16. Arterial Spin Labeling Magnetic Resonance Perfusion for Traumatic Brain Injury: Technical Challenges and Potentials.

    PubMed

    Andre, Jalal B

    2015-10-01

    Traumatic brain injury (TBI), including concussion, is a public health concern, as it affects over 1.7 million persons in the United States per year. Yet, the diagnosis of TBI, particularly mild TBI (mTBI), can be controversial, as neuroimaging findings can be sparse on conventional magnetic resonance and computed tomography examinations, and when present, often poorly correlate with clinical signs and symptoms. Furthermore, the discussion of TBI, concussion, and head impact exposure is immediately complicated by the many differing opinions of what constitutes each, their respective severities, and how the underlying biomechanics of the inciting head impact might alter the distribution, severity, and prognosis of the underlying brain injury. Advanced imaging methodologies hold promise in improving the sensitivity and detectability of associated imaging biomarkers that might better correlate with patient outcome and prognostication, allowing for improved triage and therapeutic guidance in the setting of TBI, particularly in mTBI. This work will examine the defining symptom complex associated with mTBI and explore changes in cerebral blood flow measured by arterial spin labeling, as a potential imaging biomarker for TBI, and briefly correlate these observations with findings identified by single photon emission computed tomography and positron emission tomography imaging. PMID:26502309

  17. Salicylic acid analogues as chemical exchange saturation transfer MRI contrast agents for the assessment of brain perfusion territory and blood-brain barrier opening after intra-arterial infusion.

    PubMed

    Song, Xiaolei; Walczak, Piotr; He, Xiaowei; Yang, Xing; Pearl, Monica; Bulte, Jeff Wm; Pomper, Martin G; McMahon, Michael T; Janowski, Mirosław

    2016-07-01

    The blood-brain barrier (BBB) is a major obstacle for drug delivery to the brain. Predicted, focal opening of the BBB through intra-arterial infusion of hyperosmolar mannitol is feasible, but there is a need to facilitate imaging techniques (e.g. MRI) to guide interventional procedures and assess the outcomes. Here, we show that salicylic acid analogues (SAA) can depict the brain territory supplied by the catheter and detect the BBB opening, through chemical exchange saturation transfer (CEST) MRI. Hyperosmolar SAA solutions themselves are also capable of opening the BBB, and, when multiple SAA agents were co-injected, their locoregional perfusion could be differentiated. PMID:26980755

  18. Quantitation of brain perfusion with {sup 99m}{Tc}-bicisate and single SPECT scan: Comparison with microsphere measurements

    SciTech Connect

    Pupi, A.; De Cristofaro, T.R.; Passeri, A.; Castagnoli, A.; Bacciottini, L.; Bottoncetti, A.; Dal Pozzo, G.; Santoro, G.M.; Antoniucci, D.

    1994-01-01

    This study describes and validates in a preliminary manner a method to measure the steady-state influx constant (K{sub 1}) of {sup 99m}{Tc}-bicisate with one single photon emission computed tomography (SPECT) scan. The method is based on the analysis of the arterial concentration of the radioactivity. The results of this quantitation procedure were compared with regional CBF (rCBF) measurements made using {sup 99m}{Tc}-microspheres (MI). Two quantitative indexes of perfusion, fractional brain uptake (FBU) and normalized (with cerebellum) brain uptake (NBU), were also evaluated. Two SPECT studies were performed on seven cardiovascular patients who had no signs of neurological disease. In the first of these, {sup 99m}{Tc}-bicisate was used, while in the other, which was performed 2 days later, MI were injected into the left heart ventricle. The values of the FBU, NBU, and K{sub 1} of {sup 99m}{Tc}-bicisate were calculated in several gray and white matter brain regions of interest (ROIs) and compared with the rCBF values measured with MI in coupled ROIs. Mean FBU values were 0.00008 {+-} 0.00002 and 0.00004 {+-} 0.00001 in the gray and the white matter, respectively. Mean NBU values were 0.99 {+-} 0.04 and 0.54 {+-} 0.05, mean K{sub 1} values were 0.36 {+-} 0.06 and 0.19 {+-} 0.03 ml g{sup {minus}1} min{sup {minus}1} and mean rCBF values were 0.51 {+-} 0.04 and 0.27 {+-} 0.04 ml g{sup {minus}1} min{sup {minus}1} in gray and white matter, respectively. Analysis of variance of the regression gave different F values for the regressions with rCBF of FBU (F = 19, n = 126), NBU (F = 289, n = 112), and K{sub 1}(F = 117, n = 112), and K{sub 1}(F = 117, n = 126). The regression of K{sub 1} versus rCBF was K{sub 1} = 0.08 {+-} 0.55 rCBF. 25 refs., 5 figs., 2 tabs.

  19. An electrophysiological study of the in vitro, perfused brain stem-cerebellum of adult guinea-pig.

    PubMed Central

    Llinás, R; Mühlethaler, M

    1988-01-01

    1. We describe here a technique which allows the long-term in vitro survival of the perfused isolated brain stem-cerebellum of adult guinea-pig. The viability of this preparation was assessed by comparing the electrophysiological properties of individual neurones and of neuronal pools to those obtained in vivo or in brain slices. The areas investigated included the cerebellar cortex, the inferior olive and the pontine nuclei. 2. Cerebellar field potential and intra- and extracellular single-cell recordings could be obtained for as long as 15 h after the preparation was initially isolated. The waveforms of field potentials recorded at various depths in the cerebellar cortex following surface folial stimulation were similar to those recorded in vivo. Extracellular recordings from single Purkinje cells following white matter stimulation demonstrated antidromic as well as mossy- and climbing fibre-mediated excitation. Stimulation of the cerebellar surface elicited orthodromic parallel fibre excitation of Purkinje cells and basket-stellate and Golgi cell inhibition. 3. Intrasomatic and intradendritic recordings from Purkinje cells reproduced all the phenomenology described earlier under in vivo conditions and in vitro slice preparations. In addition, spontaneous excitatory synaptic potentials generating simple spikes (mossy fibre-parallel fibre-mediated activity) and complex spikes (climbing fibre-mediated activity) were consistently observed. 4. Extracellular field potentials and extra- and intracellular recordings from inferior olive neurones were similar to those previously shown for the mammalian inferior olive. 5. Intracellular recordings were also obtained from pontine nuclei neurones, a major source of mossy fibre afferents to the cerebellum. Stimulation of the contralateral superior cerebellar peduncle produced antidromic invasion of these neurones whereas stimulation of the ipsilateral inferior cerebral peduncle resulted in their orthodromic activation. 6. The

  20. Evaluation of brain perfusion in specific Brodmann areas in Frontotemporal dementia and Alzheimer disease using automated 3-D voxel based analysis

    NASA Astrophysics Data System (ADS)

    Valotassiou, V.; Papatriantafyllou, J.; Sifakis, N.; Karageorgiou, C.; Tsougos, I.; Tzavara, C.; Zerva, C.; Georgoulias, P.

    2009-05-01

    Introduction. Brain perfusion studies with single-photon emission computed tomography (SPECT) have been applied in demented patients to provide better discrimination between frontotemporal dementia (FTD) and Alzheimer's disease (AD). Aim. To assess the perfusion of specific Brodmann (Br) areas of the brain cortex in FTD and AD patients, using NeuroGam processing program to provide 3D voxel-by-voxel cerebral SPECT analysis. Material and methods. We studied 34 consecutive patients. We used the established criteria for the diagnosis of dementia and the specific established criteria for the diagnosis of FTD and AD. All the patients had a neuropsychological evaluation with a battery of tests including the mini-mental state examination (MMSE).Twenty-six patients (16 males, 10 females, mean age 68.76±6.51 years, education 11.81±4.25 years, MMSE 16.69±9.89) received the diagnosis of FTD and 8 patients (all females, mean age 71.25±10.48 years, education 10±4.6 years, MMSE 12.5±3.89) the diagnosis of AD. All the patients underwent a brain SPECT. We applied the NeuroGam Software for the evaluation of brain perfusion in specific Br areas in the left (L) and right (R) hemispheres. Results. Statistically significant hypoperfusion in FTD compared to AD patients, was found in the following Br areas: 11L (p<0.0001), 11R, 20L, 20R, 32L, 38L, 38R, 44L (p<0.001), 32R, 36L, 36R, 45L, 45R, 47R (p<0.01), 9L, 21L, 39R, 44R, 46R, 47L (p<0.05). On the contrary, AD patients presented significant (p<0.05) hypoperfusion in 7R and 39R Br areas. Conclusion. NeuroGam processing program of brain perfusion SPECT could result in enhanced accuracy for the differential diagnosis between AD and FTD patients.

  1. MR Perfusion Imaging in Acute Ischemic Stroke

    PubMed Central

    Copen, William A.; Schaefer, Pamela W.; Wu, Ona

    2011-01-01

    MR perfusion imaging offers the potential for measuring brain perfusion in acute stroke patients, at a time when treatment decisions based upon these measurements may affect outcomes dramatically. Rapid advancements in both acute stroke therapy and perfusion imaging techniques have resulted in continuing redefinition of the role that perfusion imaging should play in patient management. This review first discusses the basic pathophysiology of acute stroke, with specific attention to alterations in the various perfusion-related parameters that can be studied by MR perfusion imaging. Although these parameters are sometimes treated as somewhat interchangeable, they reveal greatly different information about brain perfusion. Therefore, subsequent discussion of the utility of different kinds of perfusion images focuses on the differences between them, as well as important artifacts that can complicate their interpretation. Finally, research on the continually evolving role of MR perfusion imaging in acute stroke care is summarized. PMID:21640299

  2. Multislice perfusion imaging in human brain using the C-FOCI inversion pulse: comparison with hyperbolic secant.

    PubMed

    Yongbi, M N; Yang, Y; Frank, J A; Duyn, J H

    1999-12-01

    Perfusion studies based on pulsed arterial spin labeling have primarily applied hyperbolic secant (HS) pulses for spin inversion. To optimize perfusion sensitivity, it is highly desirable to implement the HS pulse with the same slice width as the width of the imaging pulse. Unfortunately, this approach causes interactions between the slice profiles and manifests as residual signal from static tissue in the resultant perfusion image. This problem is currently overcome by increasing the selective HS width relative to the imaging slice width. However, this solution increases the time for the labeled blood to reach the imaging slice (transit time), causing loss of perfusion sensitivity as a result of T(1) relaxation effects. In this study, we demonstrate that the preceding problems can be largely overcome by use of the C-shaped frequency offset corrected inversion (FOCI) pulse [Ordidge et al., Magn Reson Med 1996;36:562]. The implementation of this pulse for multislice perfusion imaging on the cerebrum is presented, showing substantial improvement in slice definition in vivo compared with the HS pulse. The sharper FOCI profile is shown to reduce the physical gap (or "safety margin") between the inversion and imaging slabs, resulting in a significant increase in perfusion signal without residual contamination from static tissue. The mean +/- SE (n = 6) gray matter perfusion-weighted signal (DeltaM/M(o)) without the application of vascular signal suppression gradients were 1.19 +/- 0. 10% (HS-flow-sensitive alternating inversion recovery [FAIR]), and 1. 51 +/- 0.11% for the FOCI-FAIR sequence. The corresponding values with vascular signal suppression were 0.64 +/- 0.14%, and 0.91 +/- 0. 08% using the HS- and FOCI-FAIR sequences, respectively. Compared with the HS-based data, the FOCI-FAIR results correspond to an average increase in perfusion signal of up to between 26%-30%. Magn Reson Med 42:1098-1105, 1999. PMID:10571931

  3. Better Glasgow outcome score, cerebral perfusion pressure and focal brain oxygenation in severely traumatized brain following direct regional brain hypothermia therapy: A prospective randomized study

    PubMed Central

    Idris, Zamzuri; Zenian, Mohd Sofan; Muzaimi, Mustapha; Hamid, Wan Zuraida Wan Abdul

    2014-01-01

    Background: Induced hypothermia for treatment of traumatic brain injury is controversial. Since many pathways involved in the pathophysiology of secondary brain injury are temperature dependent, regional brain hypothermia is thought capable to mitigate those processes. The objectives of this study are to assess the therapeutic effects and complications of regional brain cooling in severe head injury with Glasgow coma scale (GCS) 6-7. Materials and Methods: A prospective randomized controlled pilot study involving patients with severe traumatic brain injury with GCS 6 and 7 who required decompressive craniectomy. Patients were randomized into two groups: Cooling and no cooling. For the cooling group, analysis was made by dividing the group into mild and deep cooling. Brain was cooled by irrigating the brain continuously with cold Hartmann solution for 24-48 h. Main outcome assessments were a dichotomized Glasgow outcome score (GOS) at 6 months posttrauma. Results: A total of 32 patients were recruited. The cooling-treated patients did better than no cooling. There were 63.2% of patients in cooling group attained good GOS at 6 months compared to only 15.4% in noncooling group (P = 0.007). Interestingly, the analysis at 6 months post-trauma disclosed mild-cooling-treated patients did better than no cooling (70% vs. 15.4% attained good GOS, P = 0.013) and apparently, the deep-cooling-treated patients failed to be better than either no cooling (P = 0.074) or mild cooling group (P = 0.650). Conclusion: Data from this pilot study imply direct regional brain hypothermia appears safe, feasible and maybe beneficial in treating severely head-injured patients. PMID:25685201

  4. Optimising Golgi–Cox staining for use with perfusion-fixed brain tissue validated in the zQ175 mouse model of Huntington's disease

    PubMed Central

    Bayram-Weston, Zubeyde; Olsen, Elliott; Harrison, David J.; Dunnett, Stephen B.; Brooks, Simon P.

    2016-01-01

    Background The Golgi–Cox stain is an established method for characterising neuron cell morphology. The method highlights neurite processes of stained cells allowing the complexity of dendritic branching to be measured. New methods Conventional rapid Golgi and Golgi–Cox methods all require fresh impregnation in unfixed brain blocks. Here, we describe a modified method that gives high quality staining on brain tissue blocks perfusion-fixed with 4% paraformaldehyde (PFA) and post-fixed by immersion for 24 h. Results Tissue perfused with 4% PFA and post fixed for 24 h remained viable for the modified Golgi–Cox silver impregnation staining of mouse striatum from perfused wild type and zQ175. It was not found necessary to impregnate tissue blocks with Golgi solutions prior to sectioning, as post-sectioned tissues yielded equally good impregnation. Impregnation for 14 days resulted in optimal visualisation of striatal neuron and dendritic morphology. Although no modifications applied to the rapid Golgi method were reliable, the modified Golgi–Cox method yielded consistently reliable high-quality staining. Comparison with existing methods The current method used fixed tissues to reduce damage and preserve cell morphology. The revised method was found to be fast, reliable and cost effective without the need for expensive staining kits and could be performed in any neuroscience lab with limited specialist equipment. Conclusions The present study introduces a robust reproducible and inexpensive staining method for identifying neuronal morphological changes in the post fixed mouse brain, and is suitable for assessing changes in cell morphology in models of neurodegeneration and in response to experimental treatment. PMID:26459195

  5. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood-brain barrier permeability and cellular damage in the rat photothrombosis model.

    PubMed

    Schoknecht, Karl; Prager, Ofer; Vazana, Udi; Kamintsky, Lyn; Harhausen, Denise; Zille, Marietta; Figge, Lena; Chassidim, Yoash; Schellenberger, Eyk; Kovács, Richard; Heinemann, Uwe; Friedman, Alon

    2014-11-01

    Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood-brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood-brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex. PMID:25160672

  6. Monitoring stroke progression: in vivo imaging of cortical perfusion, blood–brain barrier permeability and cellular damage in the rat photothrombosis model

    PubMed Central

    Schoknecht, Karl; Prager, Ofer; Vazana, Udi; Kamintsky, Lyn; Harhausen, Denise; Zille, Marietta; Figge, Lena; Chassidim, Yoash; Schellenberger, Eyk; Kovács, Richard; Heinemann, Uwe; Friedman, Alon

    2014-01-01

    Focal cerebral ischemia is among the main causes of death and disability worldwide. The ischemic core often progresses, invading the peri-ischemic brain; however, assessing the propensity of the peri-ischemic brain to undergo secondary damage, understanding the underlying mechanisms, and adjusting treatment accordingly remain clinically unmet challenges. A significant hallmark of the peri-ischemic brain is dysfunction of the blood–brain barrier (BBB), yet the role of disturbed vascular permeability in stroke progression is unclear. Here we describe a longitudinal in vivo fluorescence imaging approach for the evaluation of cortical perfusion, BBB dysfunction, free radical formation and cellular injury using the photothrombosis vascular occlusion model in male Sprague Dawley rats. Blood–brain barrier dysfunction propagated within the peri-ischemic brain in the first hours after photothrombosis and was associated with free radical formation and cellular injury. Inhibiting free radical signaling significantly reduced progressive cellular damage after photothrombosis, with no significant effect on blood flow and BBB permeability. Our approach allows a dynamic follow-up of cellular events and their response to therapeutics in the acutely injured cerebral cortex. PMID:25160672

  7. Role of Brain Perfusion SPECT with 99mTc HMPAO in the Assessment of Response to Drug Therapy in Patients with Autoimmune Vasculitis: A Prospective Study

    PubMed Central

    Mauro, Liberatore; Manuela, Morreale; Valentina, Megna; Sara, Collorone; Chondrogiannis, Sotirios; Maria, Drudi Francesco; Christos, Anagnostou; Liana, Civitelli; Ada, Francia; Maffione, Anna Margherita; Marzola, Maria Cristina; Rubello, Domenico

    2015-01-01

    Background: The diagnosis of vasculitis in the brain remains a quite difficult achievement. To the best of our knowledge, there is no imaging method reported in literature which is capable of reaching to a diagnosis of vasculitis with very high sensitivity. Aim: The aim of this study was to determine whether perfusion brain single photon emission computed tomography (SPECT) can be usefully employed in monitoring the treatment of vasculitis, allowing treating only potentially responder patients and avoiding the side effects on patients who do not respond. Materials and Methods: Twenty patients (two males and 18 females) suffering from systemic lupus erythematosus (SLE; n = 5), Behcet's disease (BD; n = 5), undifferentiated vasculitis (UV; n = 5), and Sjogren's syndrome (SS; n = 5) were included in the study. All patients underwent a wide neurological anamnestic investigation, a complete objective neurological examination and SPECT of the brain with 99mTc-hexamethyl-propylene-aminoxime (HMPAO). The brain SPECT was then repeated after appropriate medical treatment. The neurological and neuropsychiatric follow-up was performed at 6 months after the start of the treatment. Results: Overall, the differences between the scintigraphic results obtained after and before the medical treatment indicated a statistically significant increase of the cerebral perfusion (CP). In 19 out of 200 regions of interest (ROI) studied, the difference between pre- and post treatment percentages had negative sign, indicating a worsening of CP. This latter event has occurred six times (five in the same patients) in the UV, 10 times (eight in the same patients) in the SLE, never in BD, and three times (two in the same patient) in the SS. Conclusion: The reported results seem to indicate the possibility of identifying, by the means of a brain SPECT, responder and nonresponder (unchanged or worsened CP) patients, affected by autoimmune vasculitis, to the therapy. PMID:25973400

  8. A database for estimating organ dose for coronary angiography and brain perfusion CT scans for arbitrary spectra and angular tube current modulation

    SciTech Connect

    Rupcich, Franco; Badal, Andreu; Kyprianou, Iacovos; Schmidt, Taly Gilat

    2012-09-15

    Purpose: The purpose of this study was to develop a database for estimating organ dose in a voxelized patient model for coronary angiography and brain perfusion CT acquisitions with any spectra and angular tube current modulation setting. The database enables organ dose estimation for existing and novel acquisition techniques without requiring Monte Carlo simulations. Methods: The study simulated transport of monoenergetic photons between 5 and 150 keV for 1000 projections over 360 Degree-Sign through anthropomorphic voxelized female chest and head (0 Degree-Sign and 30 Degree-Sign tilt) phantoms and standard head and body CTDI dosimetry cylinders. The simulations resulted in tables of normalized dose deposition for several radiosensitive organs quantifying the organ dose per emitted photon for each incident photon energy and projection angle for coronary angiography and brain perfusion acquisitions. The values in a table can be multiplied by an incident spectrum and number of photons at each projection angle and then summed across all energies and angles to estimate total organ dose. Scanner-specific organ dose may be approximated by normalizing the database-estimated organ dose by the database-estimated CTDI{sub vol} and multiplying by a physical CTDI{sub vol} measurement. Two examples are provided demonstrating how to use the tables to estimate relative organ dose. In the first, the change in breast and lung dose during coronary angiography CT scans is calculated for reduced kVp, angular tube current modulation, and partial angle scanning protocols relative to a reference protocol. In the second example, the change in dose to the eye lens is calculated for a brain perfusion CT acquisition in which the gantry is tilted 30 Degree-Sign relative to a nontilted scan. Results: Our database provides tables of normalized dose deposition for several radiosensitive organs irradiated during coronary angiography and brain perfusion CT scans. Validation results indicate

  9. Characterization of technetium-99m-L,L-ECD for brain perfusion imaging, Part 1: Pharmacology of technetium-99m ECD in nonhuman primates

    SciTech Connect

    Walovitch, R.C.; Hill, T.C.; Garrity, S.T.; Cheesman, E.H.; Burgess, B.A.; O'Leary, D.H.; Watson, A.D.; Ganey, M.V.; Morgan, R.A.; Williams, S.J. )

    1989-11-01

    Technetium-99m ethyl cysteinate dimer (({sup 99m}Tc)ECD) is a neutral, lipophilic complex which rapidly crosses the blood-brain barrier. Brain retention and tissue metabolism of ({sup 99m}Tc)ECD is dependent upon the stereochemical configuration of the complex. While both L,L and D,D enantiomers are extracted by the brain, only the L,L but not the D,D form, is metabolized and retained in the monkey brain (4.7% injected dose initially, T 1/2 greater than 24 hr). Dynamic single photon emission computed tomography imaging studies in one monkey indicates {sup 99m}Tc-L,L-ECD to be distributed in a pattern consistent with regional cerebral blood flow for up to 16 hr postinjection. Dual-labeled {sup 99m}Tc-L,L-ECD and ({sup 14}C)iodoantipyrine autoradiography studies performed 1 hr after administration show cortical gray to white matter ratios of both isotopes to be equivalent (approximately 4-5:1). These data suggest that {sup 99m}Tc-L,L-ECD will be useful for the scintigraphic assessment of cerebral perfusion in humans.

  10. Optimization of the method for assessment of brain perfusion in humans using contrast-enhanced reflectometry: multidistance time-resolved measurements

    NASA Astrophysics Data System (ADS)

    Milej, Daniel; Janusek, Dariusz; Gerega, Anna; Wojtkiewicz, Stanislaw; Sawosz, Piotr; Treszczanowicz, Joanna; Weigl, Wojciech; Liebert, Adam

    2015-10-01

    The aim of the study was to determine optimal measurement conditions for assessment of brain perfusion with the use of optical contrast agent and time-resolved diffuse reflectometry in the near-infrared wavelength range. The source-detector separation at which the distribution of time of flights (DTOF) of photons provided useful information on the inflow of the contrast agent to the intracerebral brain tissue compartments was determined. Series of Monte Carlo simulations was performed in which the inflow and washout of the dye in extra- and intracerebral tissue compartments was modeled and the DTOFs were obtained at different source-detector separations. Furthermore, tests on diffuse phantoms were carried out using a time-resolved setup allowing the measurement of DTOFs at 16 source-detector separations. Finally, the setup was applied in experiments carried out on the heads of adult volunteers during intravenous injection of indocyanine green. Analysis of statistical moments of the measured DTOFs showed that the source-detector separation of 6 cm is recommended for monitoring of inflow of optical contrast to the intracerebral brain tissue compartments with the use of continuous wave reflectometry, whereas the separation of 4 cm is enough when the higher-order moments of DTOFs are available.

  11. Time-resolved multi-channel optical system for assessment of brain oxygenation and perfusion by monitoring of diffuse reflectance and fluorescence

    NASA Astrophysics Data System (ADS)

    Milej, D.; Gerega, A.; Kacprzak, M.; Sawosz, P.; Weigl, W.; Maniewski, R.; Liebert, A.

    2014-03-01

    Time-resolved near-infrared spectroscopy is an optical technique which can be applied in tissue oxygenation assessment. In the last decade this method is extensively tested as a potential clinical tool for noninvasive human brain function monitoring and imaging. In the present paper we show construction of an instrument which allows for: (i) estimation of changes in brain tissue oxygenation using two-wavelength spectroscopy approach and (ii) brain perfusion assessment with the use of single-wavelength reflectometry or fluorescence measurements combined with ICG-bolus tracking. A signal processing algorithm based on statistical moments of measured distributions of times of flight of photons is implemented. This data analysis method allows for separation of signals originating from extra- and intracerebral tissue compartments. In this paper we present compact and easily reconfigurable system which can be applied in different types of time-resolved experiments: two-wavelength measurements at 687 and 832 nm, single wavelength reflectance measurements at 760 nm (which is at maximum of ICG absorption spectrum) or fluorescence measurements with excitation at 760 nm. Details of the instrument construction and results of its technical tests are shown. Furthermore, results of in-vivo measurements obtained for various modes of operation of the system are presented.

  12. In vivo evaluation of brain damage in the course of systemic lupus erythematosus using magnetic resonance spectroscopy, perfusion-weighted and diffusion-tensor imaging.

    PubMed

    Zimny, A; Szmyrka-Kaczmarek, M; Szewczyk, P; Bladowska, J; Pokryszko-Dragan, A; Gruszka, E; Wiland, P; Sasiadek, M

    2014-01-01

    Twenty-two neuropsychiatric (NPSLE) and 13 systemic lupus erythematosus (SLE) patients with a normal appearing brain on plain magnetic resonance (MR) as well as 20 age-matched healthy controls underwent MR spectroscopy (MRS), perfusion-weighted (PWI) and diffusion-tensor imaging (DTI). In MRS NAA/Cr, Cho/Cr and mI/Cr ratios were calculated from the posterior cingulate cortex and left parietal white matter. In PWI, values of cerebral blood volume (CBV) were assessed from 14 regions, including gray and white matter. In DTI fractional anisotropy (FA) values were obtained from 14 white matter tracts including projection, commissural and association fibers. All MR measurements were correlated with clinical data. SLE and NPSLE patients showed significantly (p < 0.05) lower NAA/Cr ratios within both evaluated regions and FA values within the cingulum, as well as a tendency to cortical hypoperfusion. Compared to SLE, NPSLE subjects revealed lower FA values within a wide range of association fibers and corpus callosum. Advanced MR techniques are capable of in vivo detection of complex microstructural brain damage in SLE and NPSLE subjects regarding neuronal loss, mild hypoperfusion and white matter disintegrity. MRS and DTI seem to show the highest usefulness in depicting early changes in normal appearing gray and white matter in SLE patients. PMID:24192079

  13. Effects of Open and Closed Endotracheal Suctioning on Intracranial Pressure and Cerebral Perfusion Pressure in Adult Patients With Severe Brain Injury: A Literature Review.

    PubMed

    Galbiati, Giancarlo; Paola, Cattaneo

    2015-08-01

    In neurologically impaired adult patients, endotracheal suctioning is a potentially dangerous nursing procedure because it can increase intracranial pressure (ICP) and decrease cerebral perfusion pressure (CPP). This article presents an overview of the literature relating to the appropriate techniques (open system suctioning and closed system suctioning) for minimizing variability in ICP and CPP. The research used databases such as Medline, CINAHL, Embase, Scopus, Cochrane Library, and TripDataBase. Literature published from January 1, 2002, to August 31, 2013, that involved adult patients was reviewed. The main search strings were obtained using the following keyword combinations: "suction AND intracranial pressure AND cerebrovascular circulation," "brain injuries OR craniocerebral trauma AND suction," and "brain injuries OR craniocerebral trauma AND suction AND intracranial pressure." Fourteen articles were included: two systematic reviews, two prospective nonrandomized studies, two prospective double-blind clinical trials, a crossover single-blind clinical trial, three prospective interventionist case studies, a case-control study, and three observational studies. Although most of the articles show an increased ICP above 20 mm Hg when using open system suctioning (as opposed to closed system suctioning), it is still not clear which technique is best for maintaining CPP. Therefore, further studies are needed to determine the best technique for nursing practice. PMID:25951310

  14. Central Nervous System Lymphoma in a 3-Year-Old Male Suffering from a Severe Juvenile Xanthogranuloma – the Usefulness of Perfusion Weighted Imaging and Diffusion Weighted Imaging in the Diagnostics of Pediatric Brain Tumors

    PubMed Central

    Neska-Matuszewska, Małgorzata; Zimny, Anna; Kałwak, Krzysztof; Sąsiadek, Marek J.

    2015-01-01

    Summary Background Primary Central Nervous System Lymphomas (PCNSLs) are rare, malignant brain tumors derived from lymphocytes B. Juvenile xanthogranuloma (JXG) is a non-Langerhans histiocytic cell disorder in children which mostly affects the skin. Rare fatalities have been reported in extracutaneous manifestation. Brain magnetic resonance imaging (MRI) is a method of choice in the diagnostics of all neoplastic CNS lesions. Perfusion weighted imaging (PWI) and diffusion weighted imaging (DWI) allow for more detailed analysis of brain tumors including the rate of neoangiogenesis and cellularity. We presented a pediatric patient suffering from JXG with CNS involvement and the role of brain MRI including DWI and PWI in the evaluation of brain focal lesions. Case Report A 3-year-old male with severe JXG underwent two stem cell transplantations with a development of neurological complications. The patient underwent emergency CT and MRI which revealed a non-specific enhancing focal brain lesion. In DWI it showed restricted diffusion while PWI revealed low values of rCBV and the signal intensity curve returning above the baseline level. Advanced MRI techniques such as DWI and PWI suggested PCNSL. Stereotactic biopsy confirmed PCNSL due to Ebstein-Barr virus reactivation. Conclusions The use of advanced MRI sequences is important to differentiate brain lesions in pediatric patients. The use of PWI and DWI facilitated the diagnosis of PCNSL. It is important to remember that PCNSLs show a very typical pattern of changes visualized with MRI such as: usually strong homogenous enhancement, restricted diffusion and low perfusion. PMID:25624957

  15. Effect of scatter correction on the compartmental measurement of striatal and extrastriatal dopamine D2 receptors using [123I]epidepride SPET.

    PubMed

    Fujita, Masahiro; Varrone, Andrea; Kim, Kyeong Min; Watabe, Hiroshi; Zoghbi, Sami S; Seneca, Nicholas; Tipre, Dnyanesh; Seibyl, John P; Innis, Robert B; Iida, Hidehiro

    2004-05-01

    Prior studies with anthropomorphic phantoms and single, static in vivo brain images have demonstrated that scatter correction significantly improves the accuracy of regional quantitation of single-photon emission tomography (SPET) brain images. Since the regional distribution of activity changes following a bolus injection of a typical neuroreceptor ligand, we examined the effect of scatter correction on the compartmental modeling of serial dynamic images of striatal and extrastriatal dopamine D(2) receptors using [(123)I]epidepride. Eight healthy human subjects [age 30+/-8 (range 22-46) years] participated in a study with a bolus injection of 373+/-12 (354-389) MBq [(123)I]epidepride and data acquisition over a period of 14 h. A transmission scan was obtained in each study for attenuation and scatter correction. Distribution volumes were calculated by means of compartmental nonlinear least-squares analysis using metabolite-corrected arterial input function and brain data processed with scatter correction using narrow-beam geometry micro (SC) and without scatter correction using broad-beam micro (NoSC). Effects of SC were markedly different among brain regions. SC increased activities in the putamen and thalamus after 1-1.5 h while it decreased activity during the entire experiment in the temporal cortex and cerebellum. Compared with NoSC, SC significantly increased specific distribution volume in the putamen (58%, P=0.0001) and thalamus (23%, P=0.0297). Compared with NoSC, SC made regional distribution of the specific distribution volume closer to that of [(18)F]fallypride. It is concluded that SC is required for accurate quantification of distribution volumes of receptor ligands in SPET studies. PMID:14730406

  16. Testing the hypothesis of neurodegeneracy in respiratory network function with a priori transected arterially perfused brain stem preparation of rat.

    PubMed

    Jones, Sarah E; Dutschmann, Mathias

    2016-05-01

    Degeneracy of respiratory network function would imply that anatomically discrete aspects of the brain stem are capable of producing respiratory rhythm. To test this theory we a priori transected brain stem preparations before reperfusion and reoxygenation at 4 rostrocaudal levels: 1.5 mm caudal to obex (n = 5), at obex (n = 5), and 1.5 (n = 7) and 3 mm (n = 6) rostral to obex. The respiratory activity of these preparations was assessed via recordings of phrenic and vagal nerves and lumbar spinal expiratory motor output. Preparations with a priori transection at level of the caudal brain stem did not produce stable rhythmic respiratory bursting, even when the arterial chemoreceptors were stimulated with sodium cyanide (NaCN). Reperfusion of brain stems that preserved the pre-Bötzinger complex (pre-BötC) showed spontaneous and sustained rhythmic respiratory bursting at low phrenic nerve activity (PNA) amplitude that occurred simultaneously in all respiratory motor outputs. We refer to this rhythm as the pre-BötC burstlet-type rhythm. Conserving circuitry up to the pontomedullary junction consistently produced robust high-amplitude PNA at lower burst rates, whereas sequential motor patterning across the respiratory motor outputs remained absent. Some of the rostrally transected preparations expressed both burstlet-type and regular PNA amplitude rhythms. Further analysis showed that the burstlet-type rhythm and high-amplitude PNA had 1:2 quantal relation, with burstlets appearing to trigger high-amplitude bursts. We conclude that no degenerate rhythmogenic circuits are located in the caudal medulla oblongata and confirm the pre-BötC as the primary rhythmogenic kernel. The absence of sequential motor patterning in a priori transected preparations suggests that pontine circuits govern respiratory pattern formation. PMID:26888109

  17. Contrast adaptive total p-norm variation minimization approach to CT reconstruction for artifact reduction in reduced-view brain perfusion CT

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Won; Kim, Jong-Hyo

    2011-03-01

    Perfusion CT (PCT) examinations are getting more frequently used for diagnosis of acute brain diseases such as hemorrhage and infarction, because the functional map images it produces such as regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), and mean transit time (MTT) may provide critical information in the emergency work-up of patient care. However, a typical PCT scans the same slices several tens of times after injection of contrast agent, which leads to much increased radiation dose and is inevitability of growing concern for radiation-induced cancer risk. Reducing the number of views in projection in combination of TV minimization reconstruction technique is being regarded as an option for radiation reduction. However, reconstruction artifacts due to insufficient number of X-ray projections become problematic especially when high contrast enhancement signals are present or patient's motion occurred. In this study, we present a novel reconstruction technique using contrast-adaptive TpV minimization that can reduce reconstruction artifacts effectively by using different p-norms in high contrast and low contrast objects. In the proposed method, high contrast components are first reconstructed using thresholded projection data and low p-norm total variation to reflect sparseness in both projection and reconstruction spaces. Next, projection data are modified to contain only low contrast objects by creating projection data of reconstructed high contrast components and subtracting them from original projection data. Then, the low contrast projection data are reconstructed by using relatively high p-norm TV minimization technique, and are combined with the reconstructed high contrast component images to produce final reconstructed images. The proposed algorithm was applied to numerical phantom and a clinical data set of brain PCT exam, and the resultant images were compared with those using filtered back projection (FBP) and conventional TV

  18. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion

    PubMed Central

    Ghisleni, Carmen; Bollmann, Steffen; Biason-Lauber, Anna; Poil, Simon-Shlomo; Brandeis, Daniel; Martin, Ernst; Michels, Lars; Hersberger, Martin; Suckling, John

    2015-01-01

    Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS) as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women). Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women. PMID:26356576

  19. Atrophy and lower regional perfusion of temporo-parietal brain areas are correlated with impairment in memory performances and increase of EEG upper alpha power in prodromal Alzheimer’s disease

    PubMed Central

    Moretti, Vito Davide

    2015-01-01

    Background: Temporo-parietal cortex thinning is associated with mild cognitive impairment (MCI) due to Alzheimer’s disease (AD). The increase of the EEG upper/low alpha power ratio has been associated with MCI due to AD subjects and to the atrophy of temporo-parietal brain areas. Moreover, subjects with a higher alpha3/alpha2 frequency power ratio showed lower brain perfusion than in the low alpha3/alpha2 group. The two groups have significantly different hippocampal volumes and correlation with the theta frequency activity. Methods: 74 adult subjects with MCI underwent clinical and neuropsychological evaluation, electroencephalogram (EEG) recording, and high resolution 3D magnetic resonance imaging (MRI). 27 of them underwent EEG recording and perfusion single-photon emission computed tomography (SPECT) evaluation. The alpha3/alpha2 power ratio as well as cortical thickness was computed for each subject. The difference in cortical thickness between the groups was estimated. Pearson’s r was used to assess the correlation topography between cortical thinning as well as between brain perfusion and memory impairment. Results: In the higher upper/low alpha group, memory impairment was more pronounced both in the MRI group and the SPECT MCI group. Moreover, it was correlated with greater cortical atrophy and lower perfusional rate in temporo-parietal cortex. Conclusion: High EEG upper/low alpha power ratio was associated with cortical thinning lower perfusion in temporo-parietal. Moreover, atrophy and lower perfusional rate were both significantly correlated with memory impairment in MCI subjects. The increase of EEG upper/low alpha frequency power ratio could be useful for identifying individuals at risk for progression to AD dementia and may be of value in the clinical context. PMID:26389016

  20. Sequential hypothesis testing for automatic detection of task-related changes in cerebral perfusion in a brain-computer interface.

    PubMed

    Faulkner, Hayley G; Myrden, Andrew; Li, Michael; Mamun, Khondaker; Chau, Tom

    2015-11-01

    Evidence suggests that the cerebral blood flow patterns accompanying cognitive activity are retained in many locked-in patients. These patterns can be monitored using transcranial Doppler ultrasound (TCD), a medical imaging technique that measures bilateral cerebral blood flow velocities. Recently, TCD has been proposed as an alternative imaging modality for brain-computer interfaces (BCIs). However, most previous TCD-BCI studies have performed offline analyses with impractically lengthy tasks. In this study, we designed a BCI that automatically differentiates between counting and verbal fluency tasks using sequential hypothesis testing to make decisions as quickly as possible. Ten able-bodied participants silently alternated between counting and verbal fluency tasks within the paradigm of a simulated on-screen keyboard. During this experiment, blood flow velocities were recorded within the left and right middle cerebral arteries using bilateral TCD. Twelve features were used to characterize TCD signals. In a simulated online analysis, sequential hypothesis testing was used to update estimates of class probability every 250 ms as TCD data were processed. Classification was terminated once a threshold level of certainty was reached. Mean classification accuracy across all participants was 72% after an average of 23s, compared to an offline analysis which obtained a classification accuracy of 80% after 45 s. This represents a substantial gain in data transmission rate, while maintaining classification accuracies exceeding 70%. Furthermore, a range of decision times between 19 and 28s was observed, suggesting that the ability of sequential hypothesis testing to adapt the task duration for each individual participant is critical to achieving consistent performance across participants. These results indicate that sequential hypothesis testing is a promising alternative for online TCD-BCIs. PMID:26163771

  1. Evaluation of a multiple spin- and gradient-echo (SAGE) EPI acquisition with SENSE acceleration: applications for perfusion imaging in and outside the brain.

    PubMed

    Skinner, Jack T; Robison, Ryan K; Elder, Christopher P; Newton, Allen T; Damon, Bruce M; Quarles, C Chad

    2014-12-01

    Perfusion-based changes in MR signal intensity can occur in response to the introduction of exogenous contrast agents and endogenous tissue properties (e.g. blood oxygenation). MR measurements aimed at capturing these changes often implement single-shot echo planar imaging (ssEPI). In recent years ssEPI readouts have been combined with parallel imaging (PI) to allow fast dynamic multi-slice imaging as well as the incorporation of multiple echoes. A multiple spin- and gradient-echo (SAGE) EPI acquisition has recently been developed to allow measurement of transverse relaxation rate (R2 and R2(*)) changes in dynamic susceptibility contrast (DSC)-MRI experiments in the brain. With SAGE EPI, the use of PI can influence image quality, temporal resolution, and achievable echo times. The effect of PI on dynamic SAGE measurements, however, has not been evaluated. In this work, a SAGE EPI acquisition utilizing SENSE PI and partial Fourier (PF) acceleration was developed and evaluated. Voxel-wise measures of R2 and R2(*) in healthy brain were compared using SAGE EPI and conventional non-EPI multiple echo acquisitions with varying SENSE and PF acceleration. A conservative SENSE factor of 2 with PF factor of 0.73 was found to provide accurate measures of R2 and R2(*) in white (WM) (rR2=[0.55-0.79], rR2*=[0.47-0.71]) and gray (GM) matter (rR2=[0.26-0.59], rR2*=[0.39-0.74]) across subjects. The combined use of SENSE and PF allowed the first dynamic SAGE EPI measurements in muscle, with a SENSE factor of 3 and PF factor of 0.6 providing reliable relaxation rate estimates when compared to multi-echo methods. Application of the optimized SAGE protocol in DSC-MRI of high-grade glioma patients provided T1 leakage-corrected estimates of CBV and CBF as well as mean vessel diameter (mVD) and simultaneous measures of DCE-MRI parameters K(trans) and ve. Likewise, application of SAGE in a muscle reperfusion model allowed dynamic measures of R2', a parameter that has been shown to correlate

  2. Evaluation of a Multiple Spin- and Gradient-Echo (SAGE) EPI Acquisition with SENSE Acceleration: Applications for Perfusion Imaging In and Outside the Brain

    PubMed Central

    Skinner, Jack T.; Robison, Ryan K.; Elder, Christopher P.; Newton, Allen T.; Damon, Bruce M.; Quarles, C. Chad

    2014-01-01

    Perfusion-based changes in MR signal intensity can occur in response to the introduction of exogenous contrast agents and endogenous tissue properties (e.g. blood oxygenation). MR measurements aimed at capturing these changes often implement single-shot echo planar imaging (ssEPI). In recent years ssEPI readouts have been combined with parallel imaging (PI) to allow fast dynamic multi-slice imaging as well as the incorporation of multiple echoes. A multiple spin- and gradient-echo (SAGE) EPI acquisition has recently been developed to allow measurement of transverse relaxation rate (R2 and R2*) changes in dynamic susceptibility contrast (DSC)-MRI experiments in the brain. With SAGE EPI, the use of PI can influence image quality, temporal resolution, and achievable echo times. The effect of PI on dynamic SAGE measurements, however, has not been evaluated. In this work, a SAGE EPI acquisition utilizing SENSE PI and partial Fourier (PF) acceleration was developed and evaluated. Voxel-wise measures of R2 and R2* in healthy brain were compared using SAGE EPI and conventional non-EPI multiple echo acquisitions with varying SENSE and PF acceleration. A conservative SENSE factor of 2 with PF factor of 0.73 was found to provide accurate measures of R2 and R2* in white (WM) (rR2 = [0.55–0.79], rR2* = [0.47–0.71]) and gray (GM) matter (rR2 = [0.26–0.59], rR2* = [0.39–0.74]) across subjects. The combined use of SENSE and PF allowed the first dynamic SAGE EPI measurements in muscle, with a SENSE factor of 3 and PF factor of 0.6 providing reliable relaxation rate estimates when compared to multi-echo methods. Application of the optimized SAGE protocol in DSC-MRI of high-grade glioma patients provided T1 leakage-corrected estimates of CBV and CBF as well as mean vessel diameter (mVD) and simultaneous measures of DCE-MRI parameters Ktrans and ve. Likewise, application of SAGE in a muscle reperfusion model allowed dynamic measures of R2′, a parameter that has been shown to

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

    PubMed

    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

  4. Voxel significance mapping using local image variances in subtraction ictal SPET.

    PubMed

    Brinkmann, B H; O'Brien, T J; Webster, D B; Mullan, B P; Robins, P D; Robb, R A

    2000-06-01

    Subtraction ictal SPET co-registered to MRI (SISCOM) has been shown to aid epileptogenic localization and improve surgical outcome in partial epilepsy patients. This paper reports a method of identifying significant areas of epileptogenic activation in the SISCOM subtraction image, taking into account normal variation between sequential 99Tcm-ethyl cysteinate diethylester SPET scans of single individuals, and attempts to assess the clinical value of statistical mapping in subtraction SPET. Non-linear inter-subject registration is used to combine a group of subtraction images into a common anatomical framework. A map of the pixel intensity standard deviation values in the subtraction images is created, and this map is non-linearly registered to a patient's SISCOM subtraction image. Pixels in the patient subtraction image were then evaluated based upon the statistical characteristics of corresponding pixels in the atlas. SISCOM images created with the voxel variance method were rated higher in quality than the conventional image variance method in 15 patients. No difference in localization rate was observed between the voxel variance mapping and image variance methods. The voxel significance mapping method was shown to improve the quality of clinical SISCOM images. PMID:10894564

  5. Magnetic Resonance Perfusion Imaging in the Study of Language

    ERIC Educational Resources Information Center

    Hillis, Argye E.

    2007-01-01

    This paper provides a brief review of various uses of magnetic resonance perfusion imaging in the investigation of brain/language relationships. The reviewed studies illustrate how perfusion imaging can reveal areas of brain where dysfunction due to low blood flow is associated with specific language deficits, and where restoration of blood flow…

  6. Optimizing limbic selective D2/D3 receptor occupancy by risperidone: a [123I]-epidepride SPET study.

    PubMed

    Bressan, Rodrigo A; Erlandsson, Kjell; Jones, Hugh M; Mulligan, Rachel S; Ell, Peter J; Pilowsky, Lyn S

    2003-02-01

    Selective action at limbic cortical dopamine D2-like receptors is a putative mechanism of atypical antipsychotic efficacy with few extrapyramidal side effects. Although risperidone is an atypical antipsychotic with high affinity for D2 receptors, low-dose risperidone treatment is effective without inducing extrapyramidal symptoms. The objective was to test the hypothesis that treatment with low-dose risperidone results in 'limbic selective' D2/D3 receptor blockade in vivo. Dynamic single photon emission tomography (SPET) sequences were obtained over 5 hours after injection of [123I]-epidepride (approximately 150 MBq), using a high-resolution triple-headed brain scanner (Marconi Prism 3000XP). Kinetic modelling was performed using the simplified reference region model to obtain binding potential values. Estimates of receptor occupancy were made relative to a normal volunteer control group (n = 5). Six patients treated with low-dose risperidone (mean = 2.6 mg) showed moderate levels of D2/D3 occupancy in striatum (49.9%), but higher levels of D2/D3 occupancy in thalamus (70.8%) and temporal cortex (75.2%). Occupancy values in striatum were significantly different from thalamus (F (1,4) = 26.3, p < 0.01) and from temporal cortex (F (1,4) = 53.4, p < 0.01). This is the first study to evaluate striatal and extrastriatal occupancy of risperidone. Low dose treatment with risperidone achieves a similar selectivity of limbic cortical over striatal D2/D3 receptor blockade to that of atypical antipsychotics with lower D2/D3 affinity such as clozapine, olanzapine and quetiapine. This finding is consistent with the relevance of 'limbic selective' D2/D3 receptor occupancy to the therapeutic efficacy of atypical antipsychotic drugs. PMID:12544369

  7. Early perfusion changes in patients with recurrent high-grade brain tumor treated with Bevacizumab: preliminary results by a quantitative evaluation

    PubMed Central

    2012-01-01

    Background To determine whether early monitoring of the effects of bevacizumab in patients with recurrent high-grade gliomas, by a Perfusion Computed Tomography (PCT), may be a predictor of the response to treatment assessed through conventional MRI follow-up. Methods Sixteen patients were enrolled in the present study. For each patient, two PCT examinations, before and after the first dose of bevacizumab, were acquired. Areas of abnormal Cerebral Blood Volume (CBV) were manually defined on the CBV maps, using co-registered T1- weighted images, acquired before treatment, as a guide to the tumor location. Different perfusion metrics were derived from the histogram analysis of the normalized CBV (nCBV) maps; both hyper and hypo-perfused sub-volumes were quantified in the lesion, including tumor necrosis. A two-tailed Wilcoxon test was used to establish the significance of changes in the different perfusion metrics, observed at baseline and during treatment. The relationships between changes in perfusion and morphological MRI modifications at first follow-up were investigated. Results Significant reductions in mean and median nCBV were detected throughout the entire patient population, after only a single dose of bevacizumab. The nCBV histogram modifications indicated the normalization effect of bevacizumab on the tumor abnormal vasculature. An improvement in hypoxia after a single dose of bevacizumab was predictive of a greater reduction in T1-weighted contrast-enhanced volumes at first follow-up. Conclusions These preliminary results show that a quantification of changes in necrotic intra-tumoral regions could be proposed as a potential imaging biomarker of tumor response to anti-VEGF therapies. PMID:22494770

  8. Pulmonary ventilation/perfusion scan

    MedlinePlus

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a health ...

  9. The “Skull Flap” a new conceived device for decompressive craniectomy experimental study on dogs to evaluate the safety and efficacy in reducing intracranial pressure and subsequent impact on brain perfusion

    PubMed Central

    Salvatore, Chibbaro; Fabrice, Vallee; Marco, Marsella; Leonardo, Tigan; Thomas, Lilin; Benoit, Lecuelle; Bernard, George; Pierre, Kehrli; Eric, Vicaut; Paolo, Diemidio

    2013-01-01

    Background: Decompressive craniectomy (DC) is a procedure performed increasingly often in current neurosurgical practice. Significant perioperative morbidity may be associated to this procedure because of the large skull defect; also, later closure of the skull defect (cranioplasty) may be associated to post-operative morbidity as much as any other reconstructive operation. The authors present a newly conceived/developed device: The “Skull Flap” (SF). This system, placed at the time of the craniectomy, offers the possibility to provide cranial reconstruction sparing patients a second operation. In other words, DC and cranioplasty essentially take place at the same time and in addition, patients retain their own bone flap. The current study conducted on animal models, represents the logical continuation of a prior recent study, realized on cadaver specimens, to assess the efficacy and safety of this recently developed device. Materials and Methods: This is an experimental pilot study on dogs to assess both safety and efficacy of the SF device. Two groups of experimental raised intracranial pressure animal models underwent DC; in the first group of dogs, the bone flap was left in raised position above the skull defect using the SF device; on the second group the flap was discarded. All dogs underwent transcranial Doppler (TCD) to assess brain perfusion. Head computed tomography (CT) scan to determine flap position was also obtained in the group in which the SF device was placed. Results: SF has proved to be a strong fixation device that allows satisfactory brain decompression by keeping the bone flap elevated from the swollen brain; later on, the SF allows cranial reconstruction in a simple way without requiring a second staged operation. In addition, it is relevant to note that brain perfusion was measured and found to be better in the group receiving the SF (while the flap being in a raised as well as in its natural position) comparing to the other group

  10. Brain

    MedlinePlus

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  11. The effect of head size/shape, miscentering, and bowtie filter on peak patient tissue doses from modern brain perfusion 256-slice CT: How can we minimize the risk for deterministic effects?

    SciTech Connect

    Perisinakis, Kostas; Seimenis, Ioannis; Tzedakis, Antonis; Papadakis, Antonios E.; Damilakis, John

    2013-01-15

    Purpose: To determine patient-specific absorbed peak doses to skin, eye lens, brain parenchyma, and cranial red bone marrow (RBM) of adult individuals subjected to low-dose brain perfusion CT studies on a 256-slice CT scanner, and investigate the effect of patient head size/shape, head position during the examination and bowtie filter used on peak tissue doses. Methods: The peak doses to eye lens, skin, brain, and RBM were measured in 106 individual-specific adult head phantoms subjected to the standard low-dose brain perfusion CT on a 256-slice CT scanner using a novel Monte Carlo simulation software dedicated for patient CT dosimetry. Peak tissue doses were compared to corresponding thresholds for induction of cataract, erythema, cerebrovascular disease, and depression of hematopoiesis, respectively. The effects of patient head size/shape, head position during acquisition and bowtie filter used on resulting peak patient tissue doses were investigated. The effect of eye-lens position in the scanned head region was also investigated. The effect of miscentering and use of narrow bowtie filter on image quality was assessed. Results: The mean peak doses to eye lens, skin, brain, and RBM were found to be 124, 120, 95, and 163 mGy, respectively. The effect of patient head size and shape on peak tissue doses was found to be minimal since maximum differences were less than 7%. Patient head miscentering and bowtie filter selection were found to have a considerable effect on peak tissue doses. The peak eye-lens dose saving achieved by elevating head by 4 cm with respect to isocenter and using a narrow wedge filter was found to approach 50%. When the eye lies outside of the primarily irradiated head region, the dose to eye lens was found to drop to less than 20% of the corresponding dose measured when the eye lens was located in the middle of the x-ray beam. Positioning head phantom off-isocenter by 4 cm and employing a narrow wedge filter results in a moderate reduction of

  12. Comparison between antegrade and retrograde cerebral perfusion or profound hypothermia as brain protection strategies during repair of type A aortic dissection

    PubMed Central

    Rausch, Laura A.; Kouchoukos, Nicholas T.; Lobdell, Kevin W.; Khabbaz, Kamal; Murphy, Edward; Hagberg, Robert C.

    2016-01-01

    Background The goal of this study was to compare early postoperative outcomes and actuarial-free survival between patients who underwent repair of acute type A aortic dissection by the method of cerebral perfusion used. Methods A total of 324 patients from five academic medical centers underwent repair of acute type A aortic dissection between January 2000 and December 2010. Of those, antegrade cerebral perfusion (ACP) was used for 84 patients, retrograde cerebral perfusion (RCP) was used for 55 patients, and deep hypothermic circulatory arrest (DHCA) was used for 184 patients during repair. Major morbidity, operative mortality, and 5-year actuarial survival were compared between groups. Multivariate logistic regression was used to determine predictors of operative mortality and Cox Regression hazard ratios were calculated to determine the predictors of long term mortality. Results Operative mortality was not influenced by the type of cerebral protection (19% for ACP, 14.5% for RCP and 19.1% for DHCA, P=0.729). In multivariable logistic regression analysis, hemodynamic instability [odds ratio (OR) =19.6, 95% confidence intervals (CI), 0.102–0.414, P<0.001] and CPB time >200 min(OR =4.7, 95% CI, 1.962–1.072, P=0.029) emerged as independent predictors of operative mortality. Actuarial 5-year survival was unchanged by cerebral protection modality (48.8% for ACP, 61.8% for RCP and 66.8% for no cerebral protection, log-rank P=0.844). Conclusions During surgical repair of type A aortic dissection, ACP, RCP or DHCA are safe strategies for cerebral protection in selected patients with type A aortic dissection. PMID:27563545

  13. Metabolism of [123I]epidepride may affect brain dopamine D2 receptor imaging with single-photon emission tomography.

    PubMed

    Bergström, K A; Yu, M; Kuikka, J T; Akerman, K K; Hiltunen, J; Lehtonen, J; Halldin, C; Tiihonen, J

    2000-02-01

    Iodine-123 labelled epidepride is a novel radiopharmaceutical for the study of cerebral dopamine D2 receptors using single-photon emission tomography (SPET). A lipophilic labelled metabolite of [123I]epidepride which may enter the brain and hamper the quantitation of receptors has been observed in human plasma. In the present study, gradient high-performance liquid chromatography (HPLC) was used to investigate the plasma concentration of the lipophilic labelled metabolite and its correlation to SPET imaging of striatal dopamine D2 receptors. A linear regression fit showed a negative correlation between the amount of the lipophilic labelled metabolite and the striatum to cerebellum ratio (n=16, R=-0.58, P<0.02), suggesting that plasma metabolite analysis is essential when imaging dopamine D2 receptors with SPET using [123I]epidepride. PMID:10755727

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

    PubMed

    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 < 0.05). The changes in glucose, lactate, and glycerol in the perfusate and α-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). Glutamate showed no difference between cortex and striatum in all groups (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

  15. Technetium-99m-d, 1-HM-PAO: a new radiopharmaceutical for imaging regional brain perfusion using SPECT--a comparison with iodine-123 HIPDM

    SciTech Connect

    Leonard, J.P.; Nowotnik, D.P.; Neirinckx, R.D.

    1986-12-01

    A new radiopharmaceutical, technetium-99m hexamethylpropyleneamine oxime (/sup 99m/Tc-d, 1-HM-PAO), has been reported to cross the blood-brain-barrier and to distribute in brain in proportion to regional blood flow. This study reports brain imaging obtained with /sup 99m/Tc-d,1 HM-PAO in 20 subjects; seven without evidence of cerebral disease and 13 with cerebrovascular disorders. In 16 patients comparative data were available with N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine ((/sup 123/I)HIPDM). Technetium-99m-d, 1-HM-PAO is retained sufficiently long to allow single photon emission computed tomography (SPECT) with widely available rotating gamma camera systems. The kinetics demonstrated a rapid brain uptake and prolonged retention of activity in cerebral structures. Good tomographic images are obtained with much higher uptake in gray than in white matter. Blood flow maps are comparable to those achieved with (/sup 123/I)HIPDM and established strokes were clearly seen, with similar details as in HIPDM studies. Delayed studies showed that the distribution in the brain remained virtually unchanged. Technetium-99m-d, 1-HM-PAO imaging appears particularly promising in routine examination of patients with cerebrovascular disorders.

  16. Radionuclide cerebral perfusion imaging: Normal pattern

    SciTech Connect

    Goldsmith, S.J.; Stritzke, P.; Losonczy, M.; Vallabhajosula, S.; Holan, V.; DaCosta, M.; Muzinic, M.

    1991-12-31

    Regional cerebral perfusion imaging using a new class of {sup 99m}Tc and {sup 123}I labeled compounds which traverse the blood brain barrier and SPECT imaging technology provides an opportunity to assess this physiologic phenomenon during normal cerebral function and as a manifestation of disease in the central nervous system disease. These applications pose a challenge to the nuclear medicine physician for several reasons: (a) the complex and somewhat unfamiliar functional anatomy, (b) the marked regional differences in regional cerebral perfusion at rest, (c) the lack of understanding of the effect of variations in ambient conditions on regional cerebral perfusion. The difficulties in interpretation are augmented by the display itself. There is frequently no difficulty in differentiating between gray and white matter. However, the frequently used {open_quotes}hot body{close_quotes} color maps, introduce a good deal of contrast, producing displays with apparent interruption in regional cortical perfusion whereas black and white displays provide minimal contrast in the regional cortical activity. The authors sought to define how much variation in regional cerebral perfusion is {open_quotes}allowed{close_quotes} under controlled conditions, to establish a basis to interpret if changes in the environment, psychological interventions, or disease states are accompanied by a measurable change. 2 figs., 1 tab.

  17. Accelerated median root prior reconstruction for pinhole single-photon emission tomography (SPET).

    PubMed

    Sohlberg, Antti; Ruotsalainen, Ulla; Watabe, Hiroshi; Iida, Hidehiro; Kuikka, Jyrki T

    2003-07-01

    Pinhole collimation can be used to improve spatial resolution in SPET. However, the resolution improvement is achieved at the cost of reduced sensitivity, which leads to projection images with poor statistics. Images reconstructed from these projections using the maximum likelihood expectation maximization (ML-EM) algorithms, which have been used to reduce the artefacts generated by the filtered backprojection (FBP) based reconstruction, suffer from noise/bias trade-off: noise contaminates the images at high iteration numbers, whereas early abortion of the algorithm produces images that are excessively smooth and biased towards the initial estimate of the algorithm. To limit the noise accumulation we propose the use of the pinhole median root prior (PH-MRP) reconstruction algorithm. MRP is a Bayesian reconstruction method that has already been used in PET imaging and shown to possess good noise reduction and edge preservation properties. In this study the PH-MRP algorithm was accelerated with the ordered subsets (OS) procedure and compared to the FBP, OS-EM and conventional Bayesian reconstruction methods in terms of noise reduction, quantitative accuracy, edge preservation and visual quality. The results showed that the accelerated PH-MRP algorithm was very robust. It provided visually pleasing images with lower noise level than the FBP or OS-EM and with smaller bias and sharper edges than the conventional Bayesian methods. PMID:12884928

  18. Accelerated median root prior reconstruction for pinhole single-photon emission tomography (SPET)

    NASA Astrophysics Data System (ADS)

    Sohlberg, Antti; Ruotsalainen, Ulla; Watabe, Hiroshi; Iida, Hidehiro; Kuikka, Jyrki T.

    2003-07-01

    Pinhole collimation can be used to improve spatial resolution in SPET. However, the resolution improvement is achieved at the cost of reduced sensitivity, which leads to projection images with poor statistics. Images reconstructed from these projections using the maximum likelihood expectation maximization (ML-EM) algorithms, which have been used to reduce the artefacts generated by the filtered backprojection (FBP) based reconstruction, suffer from noise/bias trade-off: noise contaminates the images at high iteration numbers, whereas early abortion of the algorithm produces images that are excessively smooth and biased towards the initial estimate of the algorithm. To limit the noise accumulation we propose the use of the pinhole median root prior (PH-MRP) reconstruction algorithm. MRP is a Bayesian reconstruction method that has already been used in PET imaging and shown to possess good noise reduction and edge preservation properties. In this study the PH-MRP algorithm was accelerated with the ordered subsets (OS) procedure and compared to the FBP, OS-EM and conventional Bayesian reconstruction methods in terms of noise reduction, quantitative accuracy, edge preservation and visual quality. The results showed that the accelerated PH-MRP algorithm was very robust. It provided visually pleasing images with lower noise level than the FBP or OS-EM and with smaller bias and sharper edges than the conventional Bayesian methods.

  19. Cerebral blood flow in patients with peritoneal dialysis by an easy Z-score imaging system for brain perfusion single-photon emission tomography.

    PubMed

    Isshiki, Rei; Kobayashi, Shuzo; Iwagami, Masao; Tsutumi, Daimu; Mochida, Yasuhiro; Ishioka, Kunihiro; Oka, Machiko; Maesato, Kyoko; Moriya, Hidekazu; Ohtake, Takayasu; Hidaka, Sumi

    2014-06-01

    Cognitive impairment has long been recognized as a complication of chronic kidney disease. However, there is little information available regarding regional cerebral blood flow (rCBF) in patients with peritoneal dialysis (PD). Therefore, we evaluated rCBF using brain single photon emission computed tomography (SPECT). We conducted a cross-sectional study in our hospital. Eighteen consecutive PD patients who could visit the hospital by themselves without any history of stroke were examined by Technetium-99 m-labeled ethylcrysteinate dimer brain SPECT. An easy Z-score imaging system (eZIS) was used to compare rCBF in PD patients with those in age-matched healthy controls. We also evaluated cognitive dysfunction with the mini-mental state examination (MMSE) questionnaire. Only one patient showed an MMSE score of 18 points, and the remaining 14 patients were considered as normal (MMSE ≥ 27), and three patients were considered to have mild cognitive impairment (24 ≤ MMSE ≤ 26). In all patients, rCBF in the posterior cingulated gyri, precunei, and parietal cortices was significantly decreased. The ratio of the reduction of rCBF in each region relative to that of rCBF across the whole brain correlated positively with the PD duration (r = 0.559; P < 0.05). The serum β2-microglobulin level was significantly higher in patients who had a higher ratio of rCBF reduction compared with those with lower ratios. In conclusion, all PD patients in the present study had decreased rCBF irrespective of MMSE scores. PMID:24965295

  20. Comparison of 99Tcm-pyrophosphate, 201T1 perfusion, 123I-labelled methyl-branched fatty acid and sympathetic imaging in acute coronary syndrome.

    PubMed

    Nakajima, K; Shuke, N; Nitta, Y; Taki, J; Matsubara, T; Terashima, N; Tonami, N; Hisada, K

    1995-06-01

    Among a group of patients (n = 15) with acute coronary syndrome, the results of using two new myocardial radiopharmaceuticals--123I-labelled 15-(p-iodo-phenyl)-3,R,S-methylpentadecanoic acid (BMIPP) and 123I-meta-iodobenzyl guanidine (MIBG)--were compared with dual 201Tl/99Tcm-pyrophosphate (Tl-PYP) imaging using single photon emission tomography (SPET). Defect scores were evaluated on a segment-by-segment basis for a total of 270 segments. For the 201Tl, BMIPP, and early and delayed MIBG studies, the mean (+/- S.D.) sums of defect scores were 9 +/- 8, 18 +/- 9, 22 +/- 12 and 29 +/- 9, respectively, revealing significantly higher scores for BMIPP and MIBG than 201Tl (P < 0.005). This was the case irrespective of various functional conditions, such as successful recanalization, failure of coronary angioplasty or restenosis. The culprit coronary artery was best identified using BMIPP, while MIBG SPET showed the most extensive defects. Normal perfusion with decreased BMIPP and MIBG uptake was frequently observed and associated with hypokinesis. 123I-BMIPP and MIBG are more sensitive for the detection of damaged myocardium, and the difference between perfusion and metabolism seems to reflect myocardial stunning. PMID:7675364

  1. Higher Brain Perfusion May Not Support Memory Functions in Cognitively Normal Carriers of the ApoE ε4 Allele Compared to Non-Carriers

    PubMed Central

    Zlatar, Zvinka Z.; Bischoff-Grethe, Amanda; Hays, Chelsea C.; Liu, Thomas T.; Meloy, M. J.; Rissman, Robert A.; Bondi, Mark W.; Wierenga, Christina E.

    2016-01-01

    Age-related changes in cerebral blood flow (CBF), which carries necessary nutrients to the brain, are associated with increased risk for mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Whether the association between CBF and cognition is moderated by apolipoprotein E (ApoE) ε4 genotype, a known risk factor for AD, remains understudied, with most research focusing on exploring brain regions in which there are diagnostic group differences in CBF (i.e., cognitively normal vs. MCI vs. AD). This study measured resting CBF via arterial spin labeling (ASL) magnetic resonance imaging (MRI) and verbal memory functions using a composite score in 59 older adults with normal cognition (38 ε3; 21 ε4). Linear mixed effect models were employed to investigate if the voxel-wise relationship between verbal memory performance and resting CBF was modified by ApoE genotype. Results indicated that carriers of the ApoE ε4 allele display negative associations between verbal memory functions and CBF in medial frontal cortex, medial and lateral temporal cortex, parietal regions, insula, and the basal ganglia. Contrarily, ε3 carriers exhibited positive associations between verbal memory functions and CBF in medial frontal cortex, thalamus, insula, and basal ganglia. Findings suggest that higher CBF was associated with worse verbal memory functions in cognitively normal ε4 carriers, perhaps reflecting dysregulation within the neurovascular unit, which is no longer supportive of cognition. Results are discussed within the context of the vascular theory of AD risk. PMID:27445794

  2. Higher Brain Perfusion May Not Support Memory Functions in Cognitively Normal Carriers of the ApoE ε4 Allele Compared to Non-Carriers.

    PubMed

    Zlatar, Zvinka Z; Bischoff-Grethe, Amanda; Hays, Chelsea C; Liu, Thomas T; Meloy, M J; Rissman, Robert A; Bondi, Mark W; Wierenga, Christina E

    2016-01-01

    Age-related changes in cerebral blood flow (CBF), which carries necessary nutrients to the brain, are associated with increased risk for mild cognitive impairment (MCI) and Alzheimer's disease (AD). Whether the association between CBF and cognition is moderated by apolipoprotein E (ApoE) ε4 genotype, a known risk factor for AD, remains understudied, with most research focusing on exploring brain regions in which there are diagnostic group differences in CBF (i.e., cognitively normal vs. MCI vs. AD). This study measured resting CBF via arterial spin labeling (ASL) magnetic resonance imaging (MRI) and verbal memory functions using a composite score in 59 older adults with normal cognition (38 ε3; 21 ε4). Linear mixed effect models were employed to investigate if the voxel-wise relationship between verbal memory performance and resting CBF was modified by ApoE genotype. Results indicated that carriers of the ApoE ε4 allele display negative associations between verbal memory functions and CBF in medial frontal cortex, medial and lateral temporal cortex, parietal regions, insula, and the basal ganglia. Contrarily, ε3 carriers exhibited positive associations between verbal memory functions and CBF in medial frontal cortex, thalamus, insula, and basal ganglia. Findings suggest that higher CBF was associated with worse verbal memory functions in cognitively normal ε4 carriers, perhaps reflecting dysregulation within the neurovascular unit, which is no longer supportive of cognition. Results are discussed within the context of the vascular theory of AD risk. PMID:27445794

  3. Low dose CT perfusion using k-means clustering

    NASA Astrophysics Data System (ADS)

    Pisana, Francesco; Henzler, Thomas; Schönberg, Stefan; Klotz, Ernst; Schmidt, Bernhard; Kachelrieß, Marc

    2016-03-01

    We aim at improving low dose CT perfusion functional parameters maps and CT images quality, preserving quantitative information. In a dynamic CT perfusion dataset, each voxel is measured T times, where T is the number of acquired time points. In this sense, we can think about a voxel as a point in a T-dimensional space, where the coordinates of the voxels would be the values of its time attenuation curve (TAC). Starting from this idea, a k-means algorithm was designed to group voxels in K classes. A modified guided time-intensity profile similarity (gTIPS) filter was implemented and applied only for those voxels belonging to the same class. The approach was tested on a digital brain perfusion phantom as well as on clinical brain and body perfusion datasets, and compared to the original TIPS implementation. The TIPS filter showed the highest CNR improvement, but lowest spatial resolution. gTIPS proved to have the best combination of spatial resolution and CNR improvement for CT images, while k-gTIPS was superior to both gTIPS and TIPS in terms of perfusion maps image quality. We demonstrate k-means clustering analysis can be applied to denoise dynamic CT perfusion data and to improve functional maps. Beside the promising results, this approach has the major benefit of being independent from the perfusion model employed for functional parameters calculation. No similar approaches were found in literature.

  4. Identification of a New Sea Urchin Ets Protein, SpEts4, by Yeast One-Hybrid Screening with the Hatching Enzyme Promoter

    PubMed Central

    Wei, Zheng; Angerer, Robert C.; Angerer, Lynne M.

    1999-01-01

    We report the use of a yeast one-hybrid system to isolate a transcriptional regulator of the sea urchin embryo hatching enzyme gene, SpHE. This gene is asymmetrically expressed along the animal-vegetal axis of sea urchin embryos under the cell-autonomous control of maternal regulatory activities and therefore provides an excellent entry point for understanding the mechanism that establishes animal-vegetal developmental polarity. To search for transcriptional regulators, we used a fragment of the SpHE promoter containing several individual elements instead of the conventional bait that contains a multimerized cis element. This screen yielded a number of positive clones that encode a new member of the Ets family, named SpEts4. This protein contains transcriptional activation activity, since expression of reporter genes in yeast does not depend on the presence of the yeast GAL4 activation domain. Sequences in the N-terminal region of SpEts4 mediate the activation activity, as shown by deletion or domain-swapping experiments. The newly identified DNA binding protein binds with a high degree of specificity to a SpHE promoter Ets element and forms a complex with a mobility identical to that obtained with 9-h sea urchin embryo nuclear extracts. SpEts4 positively regulates SpHE transcription, since mutation of the SpEts4 site in SpHE promoter transgenes reduces promoter activity in vivo while SpEts4 mRNA coinjection increases its output. As expected for a positive SpHE transcriptional regulator, the timing of SpEts4 gene expression precedes the transient expression of SpHE in the very early sea urchin blastula. PMID:9891061

  5. Parallel perfusion imaging processing using GPGPU

    PubMed Central

    Zhu, Fan; Gonzalez, David Rodriguez; Carpenter, Trevor; Atkinson, Malcolm; Wardlaw, Joanna

    2012-01-01

    Background and purpose The objective of brain perfusion quantification is to generate parametric maps of relevant hemodynamic quantities such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) that can be used in diagnosis of acute stroke. These calculations involve deconvolution operations that can be very computationally expensive when using local Arterial Input Functions (AIF). As time is vitally important in the case of acute stroke, reducing the analysis time will reduce the number of brain cells damaged and increase the potential for recovery. Methods GPUs originated as graphics generation dedicated co-processors, but modern GPUs have evolved to become a more general processor capable of executing scientific computations. It provides a highly parallel computing environment due to its large number of computing cores and constitutes an affordable high performance computing method. In this paper, we will present the implementation of a deconvolution algorithm for brain perfusion quantification on GPGPU (General Purpose Graphics Processor Units) using the CUDA programming model. We present the serial and parallel implementations of such algorithms and the evaluation of the performance gains using GPUs. Results Our method has gained a 5.56 and 3.75 speedup for CT and MR images respectively. Conclusions It seems that using GPGPU is a desirable approach in perfusion imaging analysis, which does not harm the quality of cerebral hemodynamic maps but delivers results faster than the traditional computation. PMID:22824549

  6. Towards robust deconvolution of low-dose perfusion CT: sparse perfusion deconvolution using online dictionary learning.

    PubMed

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C

    2013-05-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  7. Towards robust deconvolution of low-dose perfusion CT: Sparse perfusion deconvolution using online dictionary learning

    PubMed Central

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C.

    2014-01-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  8. Ex vivo lung perfusion.

    PubMed

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

    Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation. PMID:26700566

  9. Whole Animal Perfusion Fixation for Rodents

    PubMed Central

    Gage, Gregory J.; Kipke, Daryl R.; Shain, William

    2012-01-01

    The goal of fixation is to rapidly and uniformly preserve tissue in a life-like state. While placing tissue directly in fixative works well for small pieces of tissue, larger specimens like the intact brain pose a problem for immersion fixation because the fixative does not reach all regions of the tissue at the same rate 5,7. Often, changes in response to hypoxia begin before the tissue can be preserved 12. The advantage of directly perfusing fixative through the circulatory system is that the chemical can quickly reach every corner of the organism using the natural vascular network. In order to utilize the circulatory system most effectively, care must be taken to match physiological pressures 3. It is important to note that physiological pressures are dependent on the species used. Techniques for perfusion fixation vary depending on the tissue to be fixed and how the tissue will be processed following fixation. In this video, we describe a low-cost, rapid, controlled and uniform fixation procedure using 4% paraformaldehyde perfused via the vascular system: through the heart of the rat to obtain the best possible preservation of the brain for immunohistochemistry. The main advantage of this technique (vs. gravity-fed systems) is that the circulatory system is utilized most effectively. PMID:22871843

  10. Distribution of perfusion.

    PubMed

    Glenny, Robb; Robertson, H Thomas

    2011-01-01

    Local driving pressures and resistances within the pulmonary vascular tree determine the distribution of perfusion in the lung. Unlike other organs, these local determinants are significantly influenced by regional hydrostatic and alveolar pressures. Those effects on blood flow distribution are further magnified by the large vertical height of the human lung and the relatively low intravascular pressures in the pulmonary circulation. While the distribution of perfusion is largely due to passive determinants such as vascular geometry and hydrostatic pressures, active mechanisms such as vasoconstriction induced by local hypoxia can also redistribute blood flow. This chapter reviews the determinants of regional lung perfusion with a focus on vascular tree geometry, vertical gradients induced by gravity, the interactions between vascular and surrounding alveolar pressures, and hypoxic pulmonary vasoconstriction. While each of these determinants of perfusion distribution can be examined in isolation, the distribution of blood flow is dynamically determined and each component interacts with the others so that a change in one region of the lung influences the distribution of blood flow in other lung regions. PMID:23737171

  11. Importance of capillary perfusion.

    PubMed

    Hardaway, R M

    1979-11-01

    Perfusion is more critical than oxygen in the maintenance of cell viability. A high hematocrit or high fibrinogen level increases blood viscosity and predisposes to disseminated intravascular coagulation. It is recommended that a hematocrit of about 30 be maintained in periods of circulatory stress such as shock or extracorporeal circulation. PMID:495856

  12. New technique for retrograde cerebral perfusion during arch aneurysm repair.

    PubMed

    Bartoccioni, S; Lanzillo, G; deJong, A A; Fiaschini, P; Martinelli, G; Fedeli, C; Di Lazarro, D; Mercati, U

    1995-09-01

    Many techniques are used to reduce brain damage during surgery for dissecting aneurysms of the ascending aorta and arch. Recently, new techniques of protection were proposed, consistent with hypothermic circulatory arrest in association with retrograde cerebral perfusion via superior vena cava. We propose a simple, time-saving method, which does not require any manipulation of the heart. We use a multilumen cannula for cardioplegia (D 860-DIDECO FUNDARO') with pressure transducer. This cannula is inserted in superior vena cava by means of a simple purse-string, and linked to the arterial line with a "Y" derivation, allowing retrograde perfusion of the brain and monitoring the perfusion pressure at every moment. The superior vena cava placed downstream from the cannula is closed by a small vascular clamp, to avoid blood reflux in the right atrium. This method is time- and money-saving, is readily available, and can be prepared whenever necessary, also in the middle of the surgical procedure. PMID:7488786

  13. Lung Ventilation/Perfusion Scan

    MedlinePlus

    ... from the NHLBI on Twitter. What Is a Lung Ventilation/Perfusion Scan? A lung ventilation/perfusion scan, or VQ scan, is a ... that measures air and blood flow in your lungs. A VQ scan most often is used to ...

  14. Ex vivo lung perfusion.

    PubMed

    Machuca, Tiago N; Cypel, Marcelo

    2014-08-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  15. Ex vivo lung perfusion

    PubMed Central

    Machuca, Tiago N.

    2014-01-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. Its application in high-risk donor lungs has been successful and resulted in safe expansion of the donor pool. This article will: (I) review the technical details of EVLP; (II) the rationale behind the method; (III) report the worldwide clinical experience with the EVLP, including the Toronto technique and others; (IV) finally, discuss the growing literature on EVLP application for donation after cardiac death (DCD) lungs. PMID:25132972

  16. Framework for cognitive analysis of dynamic perfusion computed tomography with visualization of large volumetric data

    NASA Astrophysics Data System (ADS)

    Hachaj, Tomasz; Ogiela, Marek R.

    2012-10-01

    The proposed framework for cognitive analysis of perfusion computed tomography images is a fusion of image processing, pattern recognition, and image analysis procedures. The output data of the algorithm consists of: regions of perfusion abnormalities, anatomy atlas description of brain tissues, measures of perfusion parameters, and prognosis for infracted tissues. That information is superimposed onto volumetric computed tomography data and displayed to radiologists. Our rendering algorithm enables rendering large volumes on off-the-shelf hardware. This portability of rendering solution is very important because our framework can be run without using expensive dedicated hardware. The other important factors are theoretically unlimited size of rendered volume and possibility of trading of image quality for rendering speed. Such rendered, high quality visualizations may be further used for intelligent brain perfusion abnormality identification, and computer aided-diagnosis of selected types of pathologies.

  17. Double tracer autoradiographic method for sequential evaluation of regional cerebral perfusion

    SciTech Connect

    Matsuda, H.; Tsuji, S.; Oba, H.; Kinuya, K.; Terada, H.; Sumiya, H.; Shiba, K.; Mori, H.; Hisada, K.; Maeda, T. )

    1989-01-01

    A new double tracer autoradiographic method for the sequential evaluation of altered regional cerebral perfusion in the same animal is presented. This method is based on the sequential injection of two tracers, {sup 99m}Tc-hexamethylpropyleneamine oxime and N-isopropyl-({sup 125}I)p-iodoamphetamine. This method is validated in the assessment of brovincamine effects on regional cerebral perfusion in an experimental model of chronic brain ischemia in the rat. The drug enhanced perfusion recovery in low-flow areas, selectively in surrounding areas of infarction. The results suggest that this technique is of potential use in the study of neuropharmacological effects applied during the experiment.

  18. Hydrostatic determinants of cerebral perfusion

    SciTech Connect

    Wagner, E.M.; Traystman, R.J.

    1986-05-01

    We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure.

  19. Magnetic resonance perfusion imaging in proliferative cerebral angiopathy.

    PubMed

    Vargas, María Catalina; Castillo, Mauricio

    2011-01-01

    Cerebral proliferative angiopathy (CPA) is an unusual type of vascular malformation with unique clinical and imaging characteristics that distinguish it from the classic arteriovenous malformations. The features of CPA include absence of dominant arterial feeders or flow-related aneurysms, capillary angioectasia without large draining veins, and presence of intermingled normal brain parenchyma that is hypoperfused. We describe the magnetic resonance imaging findings including perfusion in 3 patients with CPA. PMID:21245687

  20. CAD of myocardial perfusion

    NASA Astrophysics Data System (ADS)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

    Our purpose is in the automated evaluation of the physiological relevance of lesions in coronary angiograms. We aim to extract as much as possible quantitative information about the physiological condition of the heart from standard angiographic image sequences. Coronary angiography is still the gold standard for evaluating and diagnosing coronary abnormalities as it is able to locate precisely the coronary artery lesions. The dimensions of the stenosis can be assessed nowadays successfully with image processing based Quantitative Coronary Angiography (QCA) techniques. Our purpose is to assess the clinical relevance of the pertinent stenosis. We therefore analyze the myocardial perfusion as revealed in standard angiographic image sequences. In a Region-of-Interest (ROI) on the angiogram (without an overlaying major blood vessel) the contrast is measured as a function of time (the so-called time-density curve). The required hyperemic state of exercise is induced artificially by the injection of a vasodilator drug e.g. papaverine. In order to minimize motion artifacts we select based on the recorded ECG signal end-diastolic images in both a basal and a hyperemic run in the same projection to position the ROI. We present the development of the algorithms together with results of a small study of 20 patients which have been catheterized following the standard protocol.

  1. Evaluation of CT Perfusion Biomarkers of Tumor Hypoxia

    PubMed Central

    Qi, Qi; Yeung, Timothy Pok Chi; Lee, Ting-Yim; Bauman, Glenn; Crukley, Cathie; Morrison, Laura; Hoffman, Lisa; Yartsev, Slav

    2016-01-01

    Background Tumor hypoxia is associated with treatment resistance to cancer therapies. Hypoxia can be investigated by immunohistopathologic methods but such procedure is invasive. A non-invasive method to interrogate tumor hypoxia is an attractive option as such method can provide information before, during, and after treatment for personalized therapies. Our study evaluated the correlations between computed tomography (CT) perfusion parameters and immunohistopathologic measurement of tumor hypoxia. Methods Wistar rats, 18 controls and 19 treated with stereotactic radiosurgery (SRS), implanted with the C6 glioma tumor were imaged using CT perfusion on average every five days to monitor tumor growth. A final CT perfusion scan and the brain were obtained on average 14 days (8–22 days) after tumor implantation. Tumor hypoxia was detected immunohistopathologically with pimonidazole. The tumor, necrotic, and pimonidazole-positive areas on histology samples were measured. Percent necrotic area and percent hypoxic areas were calculated. Tumor volume (TV), blood flow (BF), blood volume (BV), and permeability-surface area product (PS) were obtained from the CT perfusion studies. Correlations between CT perfusion parameters and histological parameters were assessed by Spearman’s ρ correlation. A Bonferroni-corrected P value < 0.05 was considered significant. Results BF and BV showed significant correlations with percent hypoxic area ρ = -0.88, P < 0.001 and ρ = -0.81, P < 0.001, respectively, for control animals and ρ = -0.7, P < 0.001 and ρ = -0.6, P = 0.003, respectively, for all animals, while TV and BV were correlated (ρ = -0.64, P = 0.01 and ρ = -0.43, P = 0.043, respectively) with percent necrotic area. PS was not correlated with either percent necrotic or percent hypoxic areas. Conclusions Percent hypoxic area provided significant correlations with BF and BV, suggesting that CT perfusion parameters are potential non-invasive imaging biomarkers of tumor

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

    PubMed Central

    Habertheuer, Andreas; Wiedemann, Dominik; Kocher, Alfred; Laufer, Guenther; Vallabhajosyula, Prashanth

    2015-01-01

    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. PMID:26713319

  3. An Appeal to Standardize CT- and MR-Perfusion.

    PubMed

    Turowski, B; Schramm, P

    2015-10-01

    Multiple treatment options and risk assessment in cerebrovascular diseases are the actual challenges in diagnostic as well as in interventional neuroradiology.Acute ischemic stroke essentially requires rapid detection of the location and extent of infarction and tissue at risk for making treatment decisions. In the acute setting, modern multiparametric perfusion imaging protocols help to determine infarct core and adjacent penumbral tissue, and they enable the estimation of collateral flow of intra- and extracranial arteries. In subacute delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) or chronic occlusive neurovascular diseases estimation of residual and collateral flow may be even more difficult.Prediction of sufficient or insufficient supply of brain tissue may be essential to balance conservative against interventional therapies. However, so far no established reliable thresholds are available for determining tissue at acute, subacute, chronic progressive, or chronic risk.Reliable and reproducible thresholds require quantitative perfusion measurements with a calibrated instrument. But the measurement instrument is not at all defined-a variety of parameter settings, different algorithms based on multiple assumptions and a wide variety of published normal and pathologic values for perfusion parameters indicate the problem. In the following text, we explain how deep the problem may be enrooted within techniques and algorithms impeding broad use of perfusion for many clinical issues. PMID:26289412

  4. Dynamic CT head phantom for perfusion and angiography studies

    NASA Astrophysics Data System (ADS)

    Russell, K.; Blazeski, A.; Dannecker, K.; Lee, Q. Y.; Holscher, C.; Donahue, C.; van Kampen, W.

    2010-03-01

    Contrast imaging is a compelling enhancement for the portable, flat panel-based brain CT scanner currently under development at Xoran. Due to the relative low temporal resolution of flat panel detectors, enabling tomographic imaging on such platform requires optimizing the imaging and injection protocols. A dynamic CT head phantom was designed to facilitate this task. The Dynamic Perfusion and Angiography Model (PAM), mimics tissue attenuation in CT images, provides physiological timing for angiography and perfusion studies, and moves fluid with properties similar to those of blood. The design consists of an arterial system, which contains bifurcating vessels that feed into perfusion chambers, mimicking blood flow through capillaries and smaller vessels, and a venous system, which is symmetrical to the arterial side and drains the perfusion chambers. The variation of geometry and flow rate in the phantom provides the physiological total time that fluid spends in the head, and the difference in material densities correlates to CT numbers for biological tissues. This paper discusses the design of Dynamic PAM and shows experimental results demonstrating its ability to realistically simulate blood flow. Results of dynamic imaging studies of the phantom are also presented.

  5. Susceptibility-Based Analysis Of Dynamic Gadolinium Bolus Perfusion MRI

    PubMed Central

    Bonekamp, David; Barker, Peter B.; Leigh, Richard; van Zijl, Peter C.M.; Li, Xu

    2014-01-01

    Purpose An algorithm is developed for the reconstruction of dynamic, gadolinium (Gd) bolus MR perfusion images of the human brain, based on quantitative susceptibility mapping (QSM). Methods The method is evaluated in 5 perfusion scans obtained from 4 different patients scanned at 3T, and compared to the conventional analysis based on changes in the transverse relaxation rate ΔR2* and to theoretical predictions. QSM images were referenced to ventricular CSF for each dynamic of the perfusion sequence. Results Images of cerebral blood flow and blood volume were successfully reconstructed from the QSM-analysis, and were comparable to those reconstructed using ΔR2*. The magnitudes of the Gd-associated susceptibility effects in gray and white matter were consistent with theoretical predictions. Conclusion QSM-based analysis may have some theoretical advantages compared to ΔR2*, including a simpler relationship between signal change and Gd concentration. However, disadvantages are its much lower contrast-to-noise ratio, artifacts due to respiration and other effects, and more complicated reconstruction methods. More work is required to optimize data acquisition protocols for QSM-based perfusion imaging. PMID:24604343

  6. Retrograde heart perfusion: the Langendorff technique of isolated heart perfusion.

    PubMed

    Bell, Robert M; Mocanu, Mihaela M; Yellon, Derek M

    2011-06-01

    In the late 19th century, a number of investigators were working on perfecting isolated heart model, but it was Oscar Langendorff who, in 1895, pioneered the isolated perfused mammalian heart. Since that time, the Langendorff preparation has evolved and provided a wealth of data underpinning our understanding of the fundamental physiology of the heart: its contractile function, coronary blood flow regulation and cardiac metabolism. In more recent times, the procedure has been used to probe pathophysiology of ischaemia/reperfusion and disease states, and with the dawn of molecular biology and genetic manipulation, the Langendorff perfused heart has remained a stalwart tool in the study of the impact upon the physiology of the heart by pharmacological inhibitors and targeted deletion or up-regulation of genes and their impact upon intracellular signalling and adaption to clinically relevant stressful stimuli. We present here the basic structure of the Langendorff system and the fundamental experimental rules which warrant a viable heart preparation. In addition, we discuss the use of the isolated retrograde perfused heart in the model of ischaemia-reperfusion injury ex-vivo, and its applicability to other areas of study. The Langendorff perfusion apparatus is highly adaptable and this is reflected not only in the procedure's longevity but also in the number of different applications to which it has been turned. PMID:21385587

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

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

    Aims: Differentiating intracranial mass lesions on CT scan is challenging. The purpose of our study was to determine the perfusion parameters in various intracranial space-occupying lesions (ICSOL), differentiate benign and malignant lesions, and differentiate between grades of gliomas. Materials and Methods: We performed CT perfusion (CTP) in 64 patients, with age ranging from 17 to 68 years, having space-occupying lesions in brain and calculated relative cerebral blood flow (rCBF) and relative cerebral blood volume (rCBV). Results: We found significantly lower perfusion in low-grade gliomas as compared to high-grade tumors, lymphoma, and metastases. Similarly in infective lesions, TWT and abscesses showed significantly lower perfusion compared to TOT. In ring enhancing lesions, capsule of TWT showed significantly lower perfusion as compared to abscesses, TOT, and metastases. Conclusion: Thus, in conclusion, infective lesions can be differentiated from tumors like lymphomas, high-grade gliomas, or metastases based on perfusion parameters. The cut off value of rCBV 1.64 can be used to differentiate between low grade and high grade gliomas. However, depending only on perfusion parameters, differentiation between the tumors like lymphomas, high-grade gliomas, and metastases may not be possible. PMID:25969639

  9. Arterial Spin Labeling Measurements of Cerebral Perfusion Territories in Experimental Ischemic Stroke

    PubMed Central

    Leoni, Renata F.; Paiva, Fernando F.; Kang, Byeong-Teck; Henning, Erica C.; Nascimento, George C.; Tannús, Alberto; De Araújo, Dráulio B.; Silva, Afonso C.

    2016-01-01

    Collateral circulation, defined as the supplementary vascular network that maintains cerebral blood flow (CBF) when the main vessels fail, constitutes one important defense mechanism of the brain against ischemic stroke. In the present study, continuous arterial spin labeling (CASL) was used to quantify CBF and obtain perfusion territory maps of the major cerebral arteries in spontaneously hypertensive rats (SHR) and their normotensive Wistar-Kyoto (WKY) controls. Results show that both WKY and SHR have complementary, yet significantly asymmetric perfusion territories. Right or left dominances were observed in territories of the anterior (ACA), middle and posterior cerebral arteries, and the thalamic artery. Magnetic resonance angiography showed that some of the asymmetries were correlated with variations of the ACA. The leptomeningeal circulation perfusing the outer layers of the cortex was observed as well. Significant and permanent changes in perfusion territories were obtained after temporary occlusion of the right middle cerebral artery in both SHR and WKY, regardless of their particular dominance. However, animals with right dominance presented a larger volume change of the left perfusion territory (23 ± 9%) than animals with left dominance (7 ± 5%, P < 0.002). The data suggest that animals with contralesional dominance primarily safeguard local CBF values with small changes in contralesional perfusion territory, while animals with ipsilesional dominance show a reversal of dominance and a substantial increase in contralesional perfusion territory. These findings show the usefulness of CASL to probe the collateral circulation. PMID:24323754

  10. Exercise training reinstates cortico-cortical sensorimotor functional connectivity following striatal lesioning: Development and application of a subregional-level analytic toolbox for perfusion autoradiographs of the rat brain

    NASA Astrophysics Data System (ADS)

    Peng, Yu-Hao; Heintz, Ryan; Wang, Zhuo; Guo, Yumei; Myers, Kalisa; Scremin, Oscar; Maarek, Jean-Michel; Holschneider, Daniel

    2014-12-01

    Current rodent connectome projects are revealing brain structural connectivity with unprecedented resolution and completeness. How subregional structural connectivity relates to subregional functional interactions is an emerging research topic. We describe a method for standardized, mesoscopic-level data sampling from autoradiographic coronal sections of the rat brain, and for correlation-based analysis and intuitive display of cortico-cortical functional connectivity (FC) on a flattened cortical map. A graphic user interface “Cx-2D” allows for the display of significant correlations of individual regions-of-interest, as well as graph theoretical metrics across the cortex. Cx-2D was tested on an autoradiographic data set of cerebral blood flow (CBF) of rats that had undergone bilateral striatal lesions, followed by 4 weeks of aerobic exercise training or no exercise. Effects of lesioning and exercise on cortico-cortical FC were examined during a locomotor challenge in this rat model of Parkinsonism. Subregional FC analysis revealed a rich functional reorganization of the brain in response to lesioning and exercise that was not apparent in a standard analysis focused on CBF of isolated brain regions. Lesioned rats showed diminished degree centrality of lateral primary motor cortex, as well as neighboring somatosensory cortex--changes that were substantially reversed in lesioned rats following exercise training. Seed analysis revealed that exercise increased positive correlations in motor and somatosensory cortex, with little effect in non-sensorimotor regions such as visual, auditory, and piriform cortex. The current analysis revealed that exercise partially reinstated sensorimotor FC lost following dopaminergic deafferentation. Cx-2D allows for standardized data sampling from images of brain slices, as well as analysis and display of cortico-cortical FC in the rat cerebral cortex with potential applications in a variety of autoradiographic and histologic

  11. Developing a tissue perfusion sensor.

    PubMed

    Harvey, S L R; Parker, K H; O'Hare, D

    2007-01-01

    The development of a electrochemical tissue perfusion sensor is presented. The sensor is a platinum/platinum ring-disc microelectrode that relies on the principle of collector-generator to monitor mass transport within its vicinity. Tissue perfusion is a mass transport mechanism that describes the movement of respiratory gases, nutrients and metabolites in tissue. The sensor's capability of detecting perfusion at the cellular level in a continuous fashion is unique. This sensor will provide insight into the way nutrients and metabolites are transported in tissue especially in cases were perfusion is low such as in wounds or ischemic tissue. We present experimental work for the development and testing of the sensors in vitro. Experimental flow recordings in free steam solutions as well as the flow through tissue-like media are shown. Tests on post operative human tissue are also presented. The sensor's feature such as the continuous recoding capacities, spatial resolution and the measurement range from ml/min to microl/min are highlighted. PMID:18002549

  12. CAD system for automatic analysis of CT perfusion maps

    NASA Astrophysics Data System (ADS)

    Hachaj, T.; Ogiela, M. R.

    2011-03-01

    In this article, authors present novel algorithms developed for the computer-assisted diagnosis (CAD) system for analysis of dynamic brain perfusion, computer tomography (CT) maps, cerebral blood flow (CBF), and cerebral blood volume (CBV). Those methods perform both quantitative analysis [detection and measurement and description with brain anatomy atlas (AA) of potential asymmetries/lesions] and qualitative analysis (semantic interpretation of visualized symptoms). The semantic interpretation (decision about type of lesion: ischemic/hemorrhagic, is the brain tissue at risk of infraction or not) of visualized symptoms is done by, so-called, cognitive inference processes allowing for reasoning on character of pathological regions based on specialist image knowledge. The whole system is implemented in.NET platform (C# programming language) and can be used on any standard PC computer with.NET framework installed.

  13. Perfusion Neuroimaging Abnormalities Alone Distinguish National Football League Players from a Healthy Population

    PubMed Central

    Amen, Daniel G.; Willeumier, Kristen; Omalu, Bennet; Newberg, Andrew; Raghavendra, Cauligi; Raji, Cyrus A.

    2016-01-01

    Background: National Football League (NFL) players are exposed to multiple head collisions during their careers. Increasing awareness of the adverse long-term effects of repetitive head trauma has raised substantial concern among players, medical professionals, and the general public. Objective: To determine whether low perfusion in specific brain regions on neuroimaging can accurately separate professional football players from healthy controls. Method: A cohort of retired and current NFL players (n = 161) were recruited in a longitudinal study starting in 2009 with ongoing interval follow up. A healthy control group (n = 124) was separately recruited for comparison. Assessments included medical examinations, neuropsychological tests, and perfusion neuroimaging with single photon emission computed tomography (SPECT). Perfusion estimates of each scan were quantified using a standard atlas. We hypothesized that hypoperfusion particularly in the orbital frontal, anterior cingulate, anterior temporal, hippocampal, amygdala, insular, caudate, superior/mid occipital, and cerebellar sub-regions alone would reliably separate controls from NFL players. Cerebral perfusion differences were calculated using a one-way ANOVA and diagnostic separation was determined with discriminant and automatic linear regression predictive models. Results: NFL players showed lower cerebral perfusion on average (p < 0.01) in 36 brain regions. The discriminant analysis subsequently distinguished NFL players from controls with 90% sensitivity, 86% specificity, and 94% accuracy (95% CI 95-99). Automatic linear modeling achieved similar results. Inclusion of age and clinical co-morbidities did not improve diagnostic classification. Conclusion: Specific brain regions commonly damaged in traumatic brain injury show abnormally low perfusion on SPECT in professional NFL players. These same regions alone can distinguish this group from healthy subjects with high diagnostic accuracy. This

  14. Central pain mechanisms following combined acid and capsaicin perfusion of the human oesophagus.

    PubMed

    Brock, Christina; Andresen, Trine; Frøkjaer, Jens Brøndum; Gale, Jeremy; Olesen, Anne Estrup; Arendt-Nielsen, Lars; Drewes, Asbjørn Mohr

    2010-03-01

    Visceral afferents originating from different gut-segments converge at the spinal level. We hypothesized that chemically-induced hyperalgesia in the oesophagus could provoke widespread visceral hypersensitivity and also influence descending modulatory pain pathways. Fifteen healthy volunteers were studied at baseline, 30, 60 and 90 min after randomized perfusion of the distal oesophagus with either saline or 180 ml 0.1M HCl+2mg capsaicin. Electro-stimulation of the oesophagus, 8 cm proximal to the perfusion site, rectosigmoid electrical stimulation and rectal mechanical and heat stimulations were used. Evoked brain potentials were recorded after electrical stimulations before and after oesophageal perfusion. After the perfusion, rectal hyperalgesia to heat (P<0.01, 37%) and mechanical (P=0.01, 11%) stimulations were demonstrated. In contrast, hypoalgesia to electro-stimulation was observed in both the oesophagus (P<0.03, 23%) and the sigmoid colon (P<0.001, 18%). Referred pain areas to electro-stimulation in oesophagus were reduced by 13% after perfusion (P=0.01). Evoked brain potentials to rectosigmoid stimulations showed decreased latencies and amplitudes of P1, N1 and P2 (P<0.05), whereas oesophagus-evoked brain potentials were unaffected after perfusion. In conclusion, modality-specific hyperalgesia was demonstrated in the lower gut following chemical sensitization of the oesophagus, reflecting widespread central hyperexcitability. Conversely, hypoalgesia to electrical stimulation, decreases in referred pain and latencies of evoked brain potentials was seen. This outcome may reflect a counterbalancing activation of descending inhibitory pathways. As these findings are also seen in the clinical setting, the model may be usable for future basic and pharmacological studies. PMID:19541517

  15. Ex vivo lung graft perfusion.

    PubMed

    Briot, Raphaël; Gennai, Stéphane; Maignan, Maxime; Souilamas, Redha; Pison, Christophe

    2016-04-01

    This review proposes an update of the state of the art and the ongoing clinical trials of ex vivo lung perfusion for lung transplantation in patients. Ex vivo lung perfusion techniques (EVLP) can be used to evaluate a lung graft outside of the body. The goal of EVLP is to study the functional status of lung grafts that were first rejected for transplantation because they did not match all criteria for a conventional transplantation. After an EVLP evaluation, some of these lungs may be requalified for a possible transplantation in patients. This article proposes an overview of the developments of EVLP techniques. During EVLP, the perfusion and ventilation of the isolated lung preparation are very progressive in order to avoid oedema due to ischaemia-reperfusion injuries. Lung evaluation is mainly based on gasometric (PaO2/FiO2) and rheological criteria (low pulmonary arterial resistance). Several series of patients transplanted with EVLP evaluated lungs have been recently published with promising results. EVLP preparations also allow a better understanding of the physiopathology and treatments of ischaemia-reperfusion injuries. Organ procurements from "non-heart-beating" donors will probably require a wider application of these ex vivo techniques. The development of semi-automated systems might facilitate the clinical use of EVLP techniques. PMID:26746565

  16. Intestinal perfusion monitoring using photoplethysmography

    NASA Astrophysics Data System (ADS)

    Akl, Tony J.; Wilson, Mark A.; Ericson, M. Nance; Coté, Gerard L.

    2013-08-01

    In abdominal trauma patients, monitoring intestinal perfusion and oxygen consumption is essential during the resuscitation period. Photoplethysmography is an optical technique potentially capable of monitoring these changes in real time to provide the medical staff with a timely and quantitative measure of the adequacy of resuscitation. The challenges for using optical techniques in monitoring hemodynamics in intestinal tissue are discussed, and the solutions to these challenges are presented using a combination of Monte Carlo modeling and theoretical analysis of light propagation in tissue. In particular, it is shown that by using visible wavelengths (i.e., 470 and 525 nm), the perfusion signal is enhanced and the background contribution is decreased compared with using traditional near-infrared wavelengths leading to an order of magnitude enhancement in the signal-to-background ratio. It was further shown that, using the visible wavelengths, similar sensitivity to oxygenation changes could be obtained (over 50% compared with that of near-infrared wavelengths). This is mainly due to the increased contrast between tissue and blood in that spectral region and the confinement of the photons to the thickness of the small intestine. Moreover, the modeling results show that the source to detector separation should be limited to roughly 6 mm while using traditional near-infrared light, with a few centimeters source to detector separation leads to poor signal-to-background ratio. Finally, a visible wavelength system is tested in an in vivo porcine study, and the possibility of monitoring intestinal perfusion changes is showed.

  17. A comparative analysis of the dependences of the hemodynamic parameters on changes in ROI's position in perfusion CT scans

    NASA Astrophysics Data System (ADS)

    Choi, Yong-Seok; Cho, Jae-Hwan; Namgung, Jang-Sun; Kim, Hyo-Jin; Yoon, Dae-Young; Lee, Han-Joo

    2013-05-01

    This study performed a comparative analysis of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and mean time-to-peak (TTP) obtained by changing the region of interest's (ROI) anatomical positions, during CT brain perfusion. We acquired axial source images of perfusion CT from 20 patients undergoing CT perfusion exams due to brain trauma. Subsequently, the CBV, CBF, MTT, and TTP values were calculated through data-processing of the perfusion CT images. The color scales for the CBV, CBF, MTT, and TTP maps were obtained using the image data. Anterior cerebral artery (ACA) was taken as the standard ROI for the calculations of the perfusion values. Differences in the hemodynamic average values were compared in a quantitative analysis by placing ROI and the dividing axial images into proximal, middle, and distal segments anatomically. By performing the qualitative analysis using a blind test, we observed changes in the sensory characteristics by using the color scales of the CBV, CBF, and MTT maps in the proximal, middle, and distal segments. According to the qualitative analysis, no differences were found in CBV, CBF, MTT, and TTP values of the proximal, middle, and distal segments and no changes were detected in the color scales of the the CBV, CBF, MTT, and TTP maps in the proximal, middle, and distal segments. We anticipate that the results of the study will useful in assessing brain trauma patients using by perfusion imaging.

  18. Excorporeal Normothermic Machine Perfusion Resuscitates Pig DCD Livers with Extended Warm Ischemia

    PubMed Central

    Xu, Hongzhi; Berendsen, Tim; Kim, Karen; Soto-Gutiérrez, Alejandro; Bertheium, Francios; Yarmush, Martin L.; Hertl, Martin

    2013-01-01

    Background The shortage in donor livers has led to increased use of allografts derived from donation after cardiac death (DCD). The compromised viability in these livers leads to inferior post-transplantation allograft function and survival compared with donation after brain death (DBD) donor grafts. In this study, we reconditioned DCD livers using an optimized normothermic machine perfusion system. Methods Livers from 12 Yorkshire pigs (20–30 kg) were subjected to either 0 min (WI-0 group, n = 6) or 60 min (WI-60 group, n = 6) of warm ischemia and 2 h of cold storage in UW solution, followed by 4 h of oxygenated sanguineous normothermic machine perfusion. Liver viability and metabolic function were analyzed hourly. Results Warm ischemic livers showed elevated transaminase levels and reduced ATP concentration. After the start of machine perfusion, transaminase levels stabilized and there was recovery of tissue ATP, coinciding with an increase in bile production. These parameters reached comparable levels to the control group after 1 h of machine perfusion. Histology and gross morphology confirmed recovery of the ischemic allografts. Conclusion Our data demonstrate that metabolic and functional parameters of livers with extended warm ischemic time (60 min) can be significantly improved using normothermic machine perfusion. We hereby compound the existing body of evidence that machine perfusion is a viable solution for reconditioning marginal organs. PMID:22099594

  19. γ-Aminobutyric acid (GABA) concentration inversely correlates with basal perfusion in human occipital lobe.

    PubMed

    Donahue, Manus J; Rane, Swati; Hussey, Erin; Mason, Emily; Pradhan, Subechhya; Waddell, Kevin W; Ally, Brandon A

    2014-03-01

    Commonly used neuroimaging approaches in humans exploit hemodynamic or metabolic indicators of brain function. However, fundamental gaps remain in our ability to relate such hemo-metabolic reactivity to neurotransmission, with recent reports providing paradoxical information regarding the relationship among basal perfusion, functional imaging contrast, and neurotransmission in awake humans. Here, sequential magnetic resonance spectroscopy (MRS) measurements of the primary inhibitory neurotransmitter, γ-aminobutyric acid (GABA+macromolecules normalized by the complex N-acetyl aspartate-N-acetyl aspartyl glutamic acid: [GABA(+)]/[NAA-NAAG]), and magnetic resonance imaging (MRI) measurements of perfusion, fractional gray-matter volume, and arterial arrival time (AAT) are recorded in human visual cortex from a controlled cohort of young adult male volunteers with neurocognitive battery-confirmed comparable cognitive capacity (3 T; n=16; age=23±3 years). Regression analyses reveal an inverse correlation between [GABA(+)]/[NAA-NAAG] and perfusion (R=-0.46; P=0.037), yet no relationship between AAT and [GABA(+)]/[NAA-NAAG] (R=-0.12; P=0.33). Perfusion measurements that do not control for AAT variations reveal reduced correlations between [GABA(+)]/[NAA-NAAG] and perfusion (R=-0.13; P=0.32). These findings largely reconcile contradictory reports between perfusion and inhibitory tone, and underscore the physiologic origins of the growing literature relating functional imaging signals, hemodynamics, and neurotransmission. PMID:24398941

  20. Analysis of D2 dopamine receptor occupancy with quantitative SPET using the high-affinity ligand [123I]epidepride: resolving conflicting findings.

    PubMed

    Erlandsson, Kjell; Bressan, Rodrigo A; Mulligan, Rachel S; Ell, Peter J; Cunningham, Vincent J; Pilowsky, Lyn S

    2003-07-01

    Recent studies of limbic cortical dopamine D(2) receptor occupancy by clozapine using high-affinity PET and SPET radioligands have produced conflicting findings. It has been suggested that these divergent findings are due to between-study differences in the method used to estimate D(2) receptor-binding potential. We compared different methods for estimating striatal and temporal cortical D(2) receptor occupancy with high-affinity tracers. In vivo experimental SPET data, obtained with [(123)I]epidepride were analysed with reference tissue kinetic modeling and with the ratio method, applied to data corresponding to short (60 min) and long (240 min) acquisition times. Dopamine D(2) receptor occupancy by the atypical antipsychotic drug risperidone was evaluated. Simulation experiments were also performed, comparing occupancy values obtained for different receptor densities in relation to different data acquisition times. The simulation results revealed that previously published data regarding errors in occupancy estimation by analysis of time activity data acquired for 60 min cannot be extrapolated to studies performed over 240 min. The ratio method provided accurate temporal cortical D(2) receptor occupancy values when applied to data from a late time period, but underestimated the occupancy with earlier data. In striatum, both the late data ratio method and reference tissue kinetic modeling using all data underestimated D(2) receptor occupancy. However, more accurate analyses of striatal D(2) occupancy still showed selective limbic/cortical occupancy by risperidone. Our results substantiate the previous [(123)I]epidepride findings of high temporal cortical occupancy by other atypical antipsychotic drugs and suggest that a potential source of conflicting findings might be short scanning times imposed by [(11)C]FLB 457, leading to underestimation of temporal cortical D(2) receptor occupancy by this method. PMID:12880845

  1. Ultrasound perfusion signal processing for tumor detection

    NASA Astrophysics Data System (ADS)

    Kim, MinWoo; Abbey, Craig K.; Insana, Michael F.

    2016-04-01

    Enhanced blood perfusion in a tissue mass is an indication of neo-vascularity and a sign of a potential malignancy. Ultrasonic pulsed-Doppler imaging is a preferred modality for noninvasive monitoring of blood flow. However, the weak blood echoes and disorganized slow flow make it difficult to detect perfusion using standard methods without the expense and risk of contrast enhancement. Our research measures the efficiency of conventional power-Doppler (PD) methods at discriminating flow states by comparing measurement performance to that of an ideal discriminator. ROC analysis applied to the experimental results shows that power Doppler methods are just 30-50 % efficient at perfusion flows less than 1ml/min, suggesting an opportunity to improve perfusion assessment through signal processing. A new perfusion estimator is proposed by extending the statistical discriminator approach. We show that 2-D perfusion color imaging may be enhanced using this approach.

  2. Modern Brain Tumor Imaging

    PubMed Central

    Barajas, Ramon F.; Cha, Soonmee

    2015-01-01

    The imaging and clinical management of patients with brain tumor continue to evolve over time and now heavily rely on physiologic imaging in addition to high-resolution structural imaging. Imaging remains a powerful noninvasive tool to positively impact the management of patients with brain tumor. This article provides an overview of the current state-of-the art clinical brain tumor imaging. In this review, we discuss general magnetic resonance (MR) imaging methods and their application to the diagnosis of, treatment planning and navigation, and disease monitoring in patients with brain tumor. We review the strengths, limitations, and pitfalls of structural imaging, diffusion-weighted imaging techniques, MR spectroscopy, perfusion imaging, positron emission tomography/MR, and functional imaging. Overall this review provides a basis for understudying the role of modern imaging in the care of brain tumor patients. PMID:25977902

  3. Myocardial perfusion imaging using contrast echocardiography.

    PubMed

    Pathan, Faraz; Marwick, Thomas H

    2015-01-01

    Microbubbles are an excellent intravascular tracer, and both the rate of myocardial opacification (analogous to coronary microvascular perfusion) and contrast intensity (analogous to myocardial blood volume) provide unique insights into myocardial perfusion. A strong evidence base has been accumulated to show comparability with nuclear perfusion imaging and incremental diagnostic and prognostic value relative to wall motion analysis. This technique also provides the possibility to measure myocardial perfusion at the bedside. Despite all of these advantages, the technique is complicated, technically challenging, and has failed to scale legislative and financial hurdles. The development of targeted imaging and therapeutic interventions will hopefully rekindle interest in this interesting modality. PMID:25817740

  4. Estimating a regional ventilation-perfusion index

    PubMed Central

    Muller, P A; Li, T; Isaacson, D; Newell, J C; Saulnier, G J; Kao, Tzu-Jen; Ashe, Jeffrey

    2015-01-01

    This is a methods paper, where an approximation to the local ventilation-perfusion ratio is derived. This approximation, called the ventilation-perfusion index since it is not exactly the physiological ventilation-perfusion ratio, is calculated using conductivity reconstructions obtained using electrical impedance tomography. Since computation of the ventilation-perfusion index only requires knowledge of the internal conductivity, any conductivity reconstruction method may be used. The method is explained, and results are presented using conductivities obtained from two EIT systems, one using an iterative method and the other a linearization method. PMID:26006279

  5. Automatic detection of CT perfusion datasets unsuitable for analysis due to head movement of acute ischemic stroke patients.

    PubMed

    Fahmi, Fahmi; Marquering, Henk A; Streekstra, Geert J; Beenen, Ludo F M; Janssen, Natasja N Y; Majoie, Charles B L; van Bavel, Ed

    2014-01-01

    Head movement during brain Computed Tomography Perfusion (CTP) can deteriorate perfusion analysis quality in acute ischemic stroke patients. We developed a method for automatic detection of CTP datasets with excessive head movement, based on 3D image-registration of CTP, with non-contrast CT providing transformation parameters. For parameter values exceeding predefined thresholds, the dataset was classified as 'severely moved'. Threshold values were determined by digital CTP phantom experiments. The automated selection was compared to manual screening by 2 experienced radiologists for 114 brain CTP datasets. Based on receiver operator characteristics, optimal thresholds were found of respectively 1.0°, 2.8° and 6.9° for pitch, roll and yaw, and 2.8 mm for z-axis translation. The proposed method had a sensitivity of 91.4% and a specificity of 82.3%. This method allows accurate automated detection of brain CTP datasets that are unsuitable for perfusion analysis. PMID:24691387

  6. Noninvasive testing of cerebral perfusion reserve prior to coronary artery bypass graft surgery

    SciTech Connect

    Levine, R.L.; Lagreze, H.L.; Berkoff, H.A.; Turnipseed, W.D.; Hanson, J.M.; Sunderland, J.J.; Nickles, R.J.; Rowe, B.R.

    1988-05-01

    Cerebral perfusion reserve testing using fluorine-18-fluoromethane and positron emission tomographic brain scanning to define cerebral blood flow abnormalities was performed in 5 patients being considered for combined coronary and carotid reconstructive surgery. Blood flow testing during normocapnia and following hypercapnia was utilized in these patients to determine the hemodynamic significance of known extracranial carotid artery occlusive lesions. Reserve diminution in 2 of these patients prompted combined surgery, whereas normal reserve values in the other 3 prompted coronary surgery alone. Results obtained in this preliminary series show how preoperative noninvasive testing of cerebral perfusion reserve adds to the diagnostic evaluation of patients with widespread vascular disease.

  7. Comparison of stroke infarction between CT perfusion and diffusion weighted imaging: preliminary results

    NASA Astrophysics Data System (ADS)

    Abd. Rahni, Ashrani Aizzuddin; Arka, Israna Hossain; Chellappan, Kalaivani; Mukari, Shahizon Azura; Law, Zhe Kang; Sahathevan, Ramesh

    2016-03-01

    In this paper we present preliminary results of comparison of automatic segmentations of the infarct core, between that obtained from CT perfusion (based on time to peak parameter) and diffusion weighted imaging (DWI). For each patient, the two imaging volumes were automatically co-registered to a common frame of reference based on an acquired CT angiography image. The accuracy of image registration is measured by the overlap of the segmented brain from both images (CT perfusion and DWI), measured within their common field of view. Due to the limitations of the study, DWI was acquired as a follow up scan up to a week after initial CT based imaging. However, we found significant overlap of the segmented brain (Jaccard indices of approximately 0.8) and the percentage of infarcted brain tissue from the two modalities were still fairly highly correlated (correlation coefficient of approximately 0.9). The results are promising with more data needed in future for clinical inference.

  8. MANGANESE TOXICOKINETICS AT THE BLOOD-BRAIN BARRIER

    EPA Science Inventory

    Investigators expect to study the mechanisms by which manganese enters and leaves the brain across the blood–brain barrier and, in particular, whether transporter molecules are involved. The investigators plan to use in vivo brain perfusion in rats as well as in vitro...

  9. Technical Pitfalls of Signal Truncation in Perfusion MRI of Glioblastoma

    PubMed Central

    Wong, Kelvin K.; Fung, Steve H.; New, Pamela Z.; Wong, Stephen T. C.

    2016-01-01

    Dynamic susceptibility contrast (DSC) perfusion-weighted imaging (PWI) is widely used in clinical settings for the radiological diagnosis of brain tumor. The signal change in brain tissue in gradient echo-based DSC PWI is much higher than in spin echo-based DSC PWI. Due to its exquisite sensitivity, gradient echo-based sequence is the preferred method for imaging of all tumors except those near the base of the skull. However, high sensitivity also comes with a dynamic range problem. It is not unusual for blood volume to increase in gene-mediated cytotoxic immunotherapy-treated glioblastoma patients. The increase of fractional blood volume sometimes saturates the MRI signal during first-pass contrast bolus arrival and presents signal truncation artifacts of various degrees in the tumor when a significant amount of blood exists in the image pixels. It presents a hidden challenge in PWI, as this signal floor can be either close to noise level or just above and can go no lower. This signal truncation in the signal intensity time course is a significant issue that deserves attention in DSC PWI. In this paper, we demonstrate that relative cerebral blood volume and relative cerebral blood flow (rCBF) are underestimated due to signal truncation in DSC perfusion, in glioblastoma patients. We propose the use of second-pass tissue residue function in rCBF calculation using least-absolute-deviation deconvolution to avoid the underestimation problem. PMID:27531989

  10. Technical Pitfalls of Signal Truncation in Perfusion MRI of Glioblastoma.

    PubMed

    Wong, Kelvin K; Fung, Steve H; New, Pamela Z; Wong, Stephen T C

    2016-01-01

    Dynamic susceptibility contrast (DSC) perfusion-weighted imaging (PWI) is widely used in clinical settings for the radiological diagnosis of brain tumor. The signal change in brain tissue in gradient echo-based DSC PWI is much higher than in spin echo-based DSC PWI. Due to its exquisite sensitivity, gradient echo-based sequence is the preferred method for imaging of all tumors except those near the base of the skull. However, high sensitivity also comes with a dynamic range problem. It is not unusual for blood volume to increase in gene-mediated cytotoxic immunotherapy-treated glioblastoma patients. The increase of fractional blood volume sometimes saturates the MRI signal during first-pass contrast bolus arrival and presents signal truncation artifacts of various degrees in the tumor when a significant amount of blood exists in the image pixels. It presents a hidden challenge in PWI, as this signal floor can be either close to noise level or just above and can go no lower. This signal truncation in the signal intensity time course is a significant issue that deserves attention in DSC PWI. In this paper, we demonstrate that relative cerebral blood volume and relative cerebral blood flow (rCBF) are underestimated due to signal truncation in DSC perfusion, in glioblastoma patients. We propose the use of second-pass tissue residue function in rCBF calculation using least-absolute-deviation deconvolution to avoid the underestimation problem. PMID:27531989

  11. Long term perfusion system supporting adipogenesis

    PubMed Central

    Abbott, Rosalyn D.; Raja, Waseem K.; Wang, Rebecca Y.; Stinson, Jordan A.; Glettig, Dean L.; Burke, Kelly A.; Kaplan, David L.

    2015-01-01

    Adipose tissue engineered models are needed to enhance our understanding of disease mechanisms and for soft tissue regenerative strategies. Perfusion systems generate more physiologically relevant and sustainable adipose tissue models, however adipocytes have unique properties that make culturing them in a perfusion environment challenging. In this paper we describe the methods involved in the development of two perfusion culture systems (2D and 3D) to test their applicability for long term in vitro adipogenic cultures. It was hypothesized that a silk protein biomaterial scaffold would provide a 3D framework, in combination with perfusion flow, to generate a more physiologically relevant sustainable adipose tissue engineered model than 2D cell culture. Consistent with other studies evaluating 2D and 3D culture systems for adipogenesis we found that both systems successfully model adipogensis, however 3D culture systems were more robust, providing the mechanical structure required to contain the large, fragile adipocytes that were lost in 2D perfused culture systems. 3D perfusion also stimulated greater lipogenesis and lipolysis and resulted in decreased secretion of LDH compared to 2D perfusion. Regardless of culture configuration (2D or 3D) greater glycerol was secreted with the increased nutritional supply provided by perfusion of fresh media. These results are promising for adipose tissue engineering applications including long term cultures for studying disease mechanisms and regenerative approaches, where both acute (days to weeks) and chronic (weeks to months) cultivation are critical for useful insight. PMID:25843606

  12. Myocardial perfusion with rubidium-82. III. Theory relating severity of coronary stenosis to perfusion deficit

    SciTech Connect

    Mullani, N.A.

    1984-11-01

    The relation between the quantitative perfusion deficit, as measured by emission computerized tomography, and the severity of coronary artery stenosis is important for the noninvasive clinical evaluation of coronary artery disease in man. Positron emission tomography allows direct noninvasive measurement of myocardial perfusion and quantification of the size of the perfusion defect. Given this important imformation, a mathematical model has been derived to gauge the severity of a coronary stenosis from quantitative perfusion measurements in the normal and poststenotic regions of the heart. The theoretical basis is presented for relating regional myocardial perfusion and regional perfusion resistance to total, coronary blood flow and resistance at normal resting flow and during maximal coronary vasodilation. The concept of perfusion reserve is presented as a clinical measure of the severity of a stenosis.

  13. Increased perfusion in motor areas after constraint-induced movement therapy in chronic stroke: a single-photon emission computerized tomography study.

    PubMed

    Könönen, Mervi; Kuikka, Jyrki T; Husso-Saastamoinen, Minna; Vanninen, Esko; Vanninen, Ritva; Soimakallio, Seppo; Mervaala, Esa; Sivenius, Juhani; Pitkänen, Kauko; Tarkka, Ina M

    2005-12-01

    Hemiparesis is the most common deficit after cerebral stroke. Constraint-induced movement therapy (CIMT) is a new neurorehabilitation method that emphasizes task-relevant repetitive training for the stroke hand. Twelve chronic stroke patients were studied with single-photon emission computerized tomography at rest before and after the two-week CIMT period. Increased perfusion was found in motor control related areas. The specific areas with an increase in perfusion in the affected hemisphere were in the precentral gyrus, premotor cortex (Brodmann's area 6 (BA6)), frontal cortex, and superior frontal gyrus (BA10). In the nonaffected hemisphere, perfusion was increased in the superior frontal gyrus (BA6) and cingulate gyrus (BA31). In the cerebellum increased perfusion was seen bilaterally. The brain areas with increased perfusion receive and integrate the information from different sensory systems and plan the movement execution. Regional cerebral perfusion decreased in the lingual gyrus (BA18) in the affected hemisphere. In the nonaffected frontal cortex, two areas with decreased perfusion were found in the middle frontal gyrus (BA8/10). Also, the fusiform gyrus (BA20) and inferior temporal gyrus (BA37) in the nonaffected hemisphere showed decreased perfusion. Intensive movement therapy appears to change local cerebral perfusion in areas known to participate in movement planning and execution. These changes might be a sign of active reorganization processes after CIMT in the chronic state of stroke. PMID:15931162

  14. [Clinical applications of arterial spin labeling technique in brain diseases].

    PubMed

    Wang, Li; Zheng, Gang; Zhao, Tiezhu; Guo, Chao; Li, Lin; Lu, Guangming

    2013-02-01

    Arterial spin labeling (ASL) technique is a kind of perfusion functional magnetic resonance imaging method that is based on endogenous contrast, and it can measure cerebral blood flow (CBF) noninvasively. The ASL technique has advantages of noninvasiveness, simplicity and relatively lower costs so that it is more suitable for longitudinal studies compared with previous perfusion methods, such as positron emission tomography (PET), single photon emission computed tomography (SPECT), CT and the contrast agent based magnetic resonance perfusion imaging. This paper mainly discusses the current clinical applications of ASL in brain diseases as cerebrovascular diseases, brain tumors, Alzheimer's disease and epilepsy, etc. PMID:23488163

  15. Value of Dynamic Susceptibility Contrast Perfusion MRI in the Acute Phase of Transient Global Amnesia

    PubMed Central

    Förster, Alex; Al-Zghloul, Mansour; Kerl, Hans U.; Böhme, Johannes; Mürle, Bettina; Groden, Christoph

    2015-01-01

    Purpose Transient global amnesia (TGA) is a transitory, short-lasting neurological disorder characterized by a sudden onset of antero- and retrograde amnesia. Perfusion abnormalities in TGA have been evaluated mainly by use of positron emission tomography (PET) or single-photon emission computed tomography (SPECT). In the present study we explore the value of dynamic susceptibility contrast perfusion-weighted MRI (PWI) in TGA in the acute phase. Methods From a MRI report database we identified TGA patients who underwent MRI including PWI in the acute phase and compared these to control subjects. Quantitative perfusion maps (cerebral blood flow (CBF) and volume (CBV)) were generated and analyzed by use of Signal Processing In NMR-Software (SPIN). CBF and CBV values in subcortical brain regions were assessed by use of VOI created in FIRST, a model-based segmentation tool in the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FSL). Results Five TGA patients were included (2 men, 3 women). On PWI, no relevant perfusion alterations were found by visual inspection in TGA patients. Group comparisons for possible differences between TGA patients and control subjects showed significant lower rCBF values bilaterally in the hippocampus, in the left thalamus and globus pallidus as well as bilaterally in the putamen and the left caudate nucleus. Correspondingly, significant lower rCBV values were observed bilaterally in the hippocampus and the putamen as well as in the left caudate nucleus. Group comparisons for possible side differences in rCBF and rCBV values in TGA patients revealed a significant lower rCBV value in the left caudate nucleus. Conclusions Mere visual inspection of PWI is not sufficient for the assessment of perfusion changes in TGA in the acute phase. Group comparisons with healthy control subjects might be useful to detect subtle perfusion changes on PWI in TGA patients. However, this should be confirmed in

  16. Dissociative Part-Dependent Resting-State Activity in Dissociative Identity Disorder: A Controlled fMRI Perfusion Study

    PubMed Central

    Schlumpf, Yolanda R.; Reinders, Antje A. T. S.; Nijenhuis, Ellert R. S.; Luechinger, Roger; van Osch, Matthias J. P.; Jäncke, Lutz

    2014-01-01

    Background In accordance with the Theory of Structural Dissociation of the Personality (TSDP), studies of dissociative identity disorder (DID) have documented that two prototypical dissociative subsystems of the personality, the “Emotional Part” (EP) and the “Apparently Normal Part” (ANP), have different biopsychosocial reactions to supraliminal and subliminal trauma-related cues and that these reactions cannot be mimicked by fantasy prone healthy controls nor by actors. Methods Arterial spin labeling perfusion MRI was used to test the hypotheses that ANP and EP in DID have different perfusion patterns in response to rest instructions, and that perfusion is different in actors who were instructed to simulate ANP and EP. In a follow-up study, regional cerebral blood flow of DID patients was compared with the activation pattern of healthy non-simulating controls. Results Compared to EP, ANP showed elevated perfusion in bilateral thalamus. Compared to ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor-related areas. Perfusion patterns for simulated ANP and EP were different. Fitting their reported role-play strategies, the actors activated brain structures involved in visual mental imagery and empathizing feelings. The follow-up study demonstrated elevated perfusion in the left temporal lobe in DID patients, whereas non-simulating healthy controls had increased activity in areas which mediate the mental construction of past and future episodic events. Conclusion DID involves dissociative part-dependent resting-state differences. Compared to ANP, EP activated brain structures involved in self-referencing and sensorimotor actions more. Actors had different perfusion patterns compared to genuine ANP and EP. Comparisons of neural activity for individuals with DID and non-DID simulating controls suggest that the resting-state features of ANP and EP in DID are not due to imagination. The findings are

  17. TISSUE ENGINEERING PERFUSABLE CANCER MODELS

    PubMed Central

    Fong, E.L.; Santoro, M.; Farach-Carson, M.C.; Kasper, F.K.; Mikos, A.G.

    2014-01-01

    The effect of fluid flow on cancer progression is currently not well understood, highlighting the need for perfused tumor models to close this gap in knowledge. Enabling biological processes at the cellular level to be modeled with high spatiotemporal control, microfluidic tumor models have demonstrated applicability as platforms to study cell-cell interactions, effect of interstitial flow on tumor migration and the role of vascular barrier function. To account for the multi-scale nature of cancer growth and invasion, macroscale models are also necessary. The consideration of fluid dynamics within tumor models at both the micro- and macroscopic levels may greatly improve our ability to more fully mimic the tumor microenvironment. PMID:24634812

  18. Correlation of CT perfusion and CT volumetry in patients with Alzheimer’s disease

    PubMed Central

    Czarnecka, Anna; Zimny, Anna; Sąsiadek, Marek

    2010-01-01

    Summary Background: Both brain atrophy and decrease of perfusion are observed in dementive diseases. The aim of the study was to correlate the results of brain perfusion CT (pCT) and CT volumetry in patients with Alzheimer’s disease (AD). Material/Methods: Forty-eight patients with AD (mean age of 71.3 years) underwent brain pCT and CT volumetry. The pCT was performed at the level of basal ganglia after the injection of contrast medium (50 ml, 4 ml/sec.) with serial scanning (delay 7 sec, 50 scans, 1 scan/sec). Volumetric measurements were carried out on the basis of source images, with the use of a dedicated CT software combined with manual outlining of the regions of interest in extracerebral and intraventricular CSF spaces. Perfusion parameters of the cerebral blood flow (CBF) and cerebral blood volume (CBV) from the grey matter of frontal and temporal as well as basal ganglia were compared statistically with the volumetric measurements of frontal and temporal cortical atrophy as well as subcortical atrophy. Results: A statistically significant positive correlation was found between the values of CBF and CBV in the basal ganglia and the volumes of the lateral and third ventricles. The comparison of CBF and CBV results with the volumetric measurements in the areas of the frontal and temporal lobes showed mostly negative correlations, but none of them was of statistical significance. Conclusions: In patients with AD, the degree of cortical atrophy is not correlated with the decrease of perfusion in the grey matter and subcortical atrophy is not correlated with the decrease of perfusion in the basal ganglia region. It suggests that functional and structural changes in AD are not related to each other. PMID:22802771

  19. Functional cluster analysis of CT perfusion maps: a new tool for diagnosis of acute stroke?

    PubMed

    Baumgartner, Christian; Gautsch, Kurt; Böhm, Christian; Felber, Stephan

    2005-09-01

    CT perfusion imaging constitutes an important contribution to the early diagnosis of acute stroke. Cerebral blood flow (CBF), cerebral blood volume (CBV) and time-to-peak (TTP) maps are used to estimate the severity of cerebral damage after acute ischemia. We introduce functional cluster analysis as a new tool to evaluate CT perfusion in order to identify normal brain, ischemic tissue and large vessels. CBF, CBV and TTP maps represent the basis for cluster analysis applying a partitioning (k-means) and density-based (density-based spatial clustering of applications with noise, DBSCAN) paradigm. In patients with transient ischemic attack and stroke, cluster analysis identified brain areas with distinct hemodynamic properties (gray and white matter) and segmented territorial ischemia. CBF, CBV and TTP values of each detected cluster were displayed. Our preliminary results indicate that functional cluster analysis of CT perfusion maps may become a helpful tool for the interpretation of perfusion maps and provide a rapid means for the segmentation of ischemic tissue. PMID:15827821

  20. Ventilation-perfusion imaging in pulmonary papillomatosis

    SciTech Connect

    Espinola, D.; Rupani, H.; Camargo, E.E.; Wagner, H.N. Jr.

    1981-11-01

    Three children with laryngeal papillomas involving the lungs had serial ventilation-perfusion scintigrams to assess results of therapy designed to reduce the bronchial involvement. Different imaging patterns were observed depending on size, number, and location of lesions. In early parenchymal involvement a ventilation-perfusion mismatch was seen. The initial and follow-up studies correlated well with clinical and radiographic findings. This noninvasive procedure is helpful in evaluating ventilatory and perfusion impairment in these patients as well as their response to treatment.

  1. Cochlear perfusion with a viscous fluid.

    PubMed

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

    The flow of viscous fluid in the cochlea induces shear forces, which could provide benefit in clinical practice, for example to guide cochlear implant insertion or produce static pressure to the cochlear partition or wall. From a research standpoint, studying the effects of a viscous fluid in the cochlea provides data for better understanding cochlear fluid mechanics. However, cochlear perfusion with a viscous fluid may damage the cochlea. In this work we studied the physiological and anatomical effects of perfusing the cochlea with a viscous fluid. Gerbil cochleae were perfused at a rate of 2.4 μL/min with artificial perilymph (AP) and sodium hyaluronate (Healon, HA) in four different concentrations (0.0625%, 0.125%, 0.25%, 0.5%). The different HA concentrations were applied either sequentially in the same cochlea or individually in different cochleae. The perfusion fluid entered from the round window and was withdrawn from basal scala vestibuli, in order to perfuse the entire perilymphatic space. Compound action potentials (CAP) were measured after each perfusion. After perfusion with increasing concentrations of HA in the order of increasing viscosity, the CAP thresholds generally increased. The threshold elevation after AP and 0.0625% HA perfusion was small or almost zero, and the 0.125% HA was a borderline case, while the higher concentrations significantly elevated CAP thresholds. Histology of the cochleae perfused with the 0.0625% HA showed an intact Reissner's membrane (RM), while in cochleae perfused with 0.125% and 0.25% HA RM was torn. Thus, the CAP threshold elevation was likely due to the broken RM, likely caused by the shear stress produced by the flow of the viscous fluid. Our results and analysis indicate that the cochlea can sustain, without a significant CAP threshold shift, up to a 1.5 Pa shear stress. Beside these finding, in the 0.125% and 0.25% HA perfusion cases, a temporary CAP threshold shift was observed, perhaps due to the presence and

  2. Luminal distension as a possible consequence of experimental intestinal perfusion

    PubMed Central

    Wingate, David; Hyams, Ashley; Phillips, Sidney

    1974-01-01

    In an experimental jejunal perfusion study, distress in healthy subjects occurred during eight out of 16 perfusions in which intestinal secretion was provoked. Calculation demonstrates the volumetric consequences of inadequate recovery of secretory perfusates, and analysis of the perfusion studies shows that distress was significantly associated with poor recovery of the perfusate. These observations are pertinent to increasing interest in the phenomenon of intestinal fluid secretion. PMID:4435588

  3. Perfusion education and training in Europe.

    PubMed

    Merkle, Frank

    2006-01-01

    Perfusion education and training varies considerably throughout Europe. Unlike in the US, where a common curriculum for perfusion education has been established, each European country has its own education system. This fact is further complicated by a multitude of national languages and cultures. Thus, perfusion education programmes vary, not only in content, but also in their academic levels. This article aims to give a comprehensive overview of the situation in each of the 20 member states of the European Board of Cardiovascular Perfusion (EBCP). The EBCP delegates were polled for a description of the process of training and education of clinical perfusionists in their respective countries. Following the initial delegate poll in 2001, an update of the material was performed in spring 2005. In summary, training of clinical perfusionists in Europe varies considerably between countries. A professional body is necessary to oversee the training process and to guarantee a minimum level of clinical competency for cardiovascular perfusionists. PMID:16485693

  4. Myocardial perfusion imaging with 201Tl.

    PubMed

    Pagnanelli, Robert A; Basso, Danny A

    2010-03-01

    The object of this review is to provide information about (201)Tl-thallous chloride in radionuclide myocardial perfusion imaging. This technique has experienced a recent resurgence because of the shortage of (99m)Tc. After reading this article, the technologist will be able to describe the properties and uptake mechanism of (201)Tl, the procedure for myocardial perfusion imaging with this agent, and the advantages and disadvantages of thallium, compared with the technetium agents. PMID:20159930

  5. Improved exercise myocardial perfusion during lidoflazine therapy

    SciTech Connect

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-11-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise.

  6. Perfusion visualization and analysis for pulmonary embolism

    NASA Astrophysics Data System (ADS)

    Vaz, Michael S.; Kiraly, Atilla P.; Naidich, David P.; Novak, Carol L.

    2005-04-01

    Given the nature of pulmonary embolism (PE), timely and accurate diagnosis is critical. Contrast enhanced high-resolution CT images allow physicians to accurately identify segmental and sub-segmental emboli. However, it is also important to assess the effect of such emboli on the blood flow in the lungs. Expanding upon previous research, we propose a method for 3D visualization of lung perfusion. The proposed method allows users to examine perfusion throughout the entire lung volume at a single glance, with areas of diminished perfusion highlighted so that they are visible independent of the viewing location. This may be particularly valuable for better accuracy in assessing the extent of hemodynamic alterations resulting from pulmonary emboli. The method also facilitates user interaction and may help identify small peripheral sub-segmental emboli otherwise overlooked. 19 patients referred for possible PE were evaluated by CT following the administration of IV contrast media. An experienced thoracic radiologist assessed the 19 datasets with 17 diagnosed as being positive for PE with multiple emboli. Since anomalies in lung perfusion due to PE can alter the distribution of parenchymal densities, we analyzed features collected from histograms of the computed perfusion maps and demonstrate their potential usefulness as a preliminary test to suggest the presence of PE. These histogram features also offer the possibility of distinguishing distinct patterns associated with chronic PE and may even be useful for further characterization of changes in perfusion or overall density resulting from associated conditions such as pneumonia or diffuse lung disease.

  7. Methodology for ventilation/perfusion SPECT.

    PubMed

    Bajc, Marika; Neilly, Brian; Miniati, Massimo; Mortensen, Jan; Jonson, Björn

    2010-11-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices in all projections as well as in rotating volume images based upon maximum intensity projections. Probabilistic interpretation of V/Q SPECT should be replaced by a holistic interpretation strategy on the basis of all relevant information about the patient and all ventilation/perfusion patterns. PE is diagnosed when there is more than one subsegment showing a V/Q mismatch representing an anatomic lung unit. Apart from pulmonary embolism, other pathologies should be identified and reported, for example, obstructive disease, heart failure, and pneumonia. Pitfalls exist both with respect to imaging technique and scan interpretation. PMID:20920632

  8. Computed tomography perfusion imaging denoising using Gaussian process regression

    NASA Astrophysics Data System (ADS)

    Zhu, Fan; Carpenter, Trevor; Rodriguez Gonzalez, David; Atkinson, Malcolm; Wardlaw, Joanna

    2012-06-01

    Brain perfusion weighted images acquired using dynamic contrast studies have an important clinical role in acute stroke diagnosis and treatment decisions. However, computed tomography (CT) images suffer from low contrast-to-noise ratios (CNR) as a consequence of the limitation of the exposure to radiation of the patient. As a consequence, the developments of methods for improving the CNR are valuable. The majority of existing approaches for denoising CT images are optimized for 3D (spatial) information, including spatial decimation (spatially weighted mean filters) and techniques based on wavelet and curvelet transforms. However, perfusion imaging data is 4D as it also contains temporal information. Our approach using Gaussian process regression (GPR), which takes advantage of the temporal information, to reduce the noise level. Over the entire image, GPR gains a 99% CNR improvement over the raw images and also improves the quality of haemodynamic maps allowing a better identification of edges and detailed information. At the level of individual voxel, GPR provides a stable baseline, helps us to identify key parameters from tissue time-concentration curves and reduces the oscillations in the curve. GPR is superior to the comparable techniques used in this study.

  9. Computed tomography perfusion imaging denoising using gaussian process regression.

    PubMed

    Zhu, Fan; Carpenter, Trevor; Rodriguez Gonzalez, David; Atkinson, Malcolm; Wardlaw, Joanna

    2012-06-21

    Brain perfusion weighted images acquired using dynamic contrast studies have an important clinical role in acute stroke diagnosis and treatment decisions. However, computed tomography (CT) images suffer from low contrast-to-noise ratios (CNR) as a consequence of the limitation of the exposure to radiation of the patient. As a consequence, the developments of methods for improving the CNR are valuable. The majority of existing approaches for denoising CT images are optimized for 3D (spatial) information, including spatial decimation (spatially weighted mean filters) and techniques based on wavelet and curvelet transforms. However, perfusion imaging data is 4D as it also contains temporal information. Our approach using gaussian process regression (GPR), which takes advantage of the temporal information, to reduce the noise level. Over the entire image, GPR gains a 99% CNR improvement over the raw images and also improves the quality of haemodynamic maps allowing a better identification of edges and detailed information. At the level of individual voxel, GPR provides a stable baseline, helps us to identify key parameters from tissue time-concentration curves and reduces the oscillations in the curve. GPR is superior to the comparable techniques used in this study. PMID:22617159

  10. Hypothermic machine perfusion of the liver and the critical balance between perfusion pressures and endothelial injury.

    PubMed

    't Hart, N A; van der Plaats, A; Leuvenink, H G D; van Goor, H; Wiersema-Buist, J; Verkerke, G J; Rakhorst, G; Ploeg, R J

    2005-01-01

    Hypothermic machine perfusion (HMP) provides better protection against cold ischemic injury than cold storage in marginal donor kidneys. Also, in liver transplantation a switch from static cold storage to HMP could be beneficial as it would allow longer preservation times and the use of marginal donors. A critical question concerning application of HMP in liver preservation is the crucial balance between perfusion pressure and occurrence of endothelial injury. Rat livers were cold-perfused for 24 hours to study perfusion pressures for both hepatic artery and portal vein. Cold storage served as control and was compared to HMP-preserved livers using a mean arterial perfusion pressure of 25 mm Hg and a portal perfusion pressure of 4 mm Hg (25% of normothermic liver circulation) and to HMP at 50 mm Hg and 8 mm Hg perfusion, respectively (50% of normothermic liver circulation). UW solution was enriched with 14.9 micromol/L propidium iodide (PI) to stain for dead cells and with an additional 13.5 micromol/L acridine orange to stain for viable hepatocytes. A low PI-positive cell count was found using HMP at 25% of normal circulation compared to cold storage. The PI count was high for the HMP group perfused at just 50% of normal circulation compared to HMP at 25% and compared to cold storage. In summary, for liver HMP, perfusion at 25% showed complete perfusion with minimal cellular injury. HMP using perfusion pressures of 25 mm Hg for the hepatic artery and 4 mm Hg for the portal vein is feasible without induction of endothelial injury. PMID:15808634

  11. [Pulmonary ventilation/perfusion ratio].

    PubMed

    Guenard, H

    1987-01-01

    The ratios of ventilatory (V) and perfusion (Q) flow rates in the lung are to a large extent responsible for the efficiency of gas exchange. In a simplified monocompartmental model of the lung, the arterial partial pressure of a given gas (Pa) is a function of several factors: the solubility of this gas in blood, its venous and inspired partial pressures and the V/Q ratio. In a multicompartemental model, the mean arterial partial pressure of the gas is a function of the individual values of Pa in each compartment as well as the distribution of V/Q ratios in the lung and the relationship between the concentration and the partial pressure of the gas. The heterogeneity of the distribution of V/Q results from those of both V and Q. Two factors are mainly responsible for this heterogeneity: the gravity and the morphometric characteristics of bronchi and vessels. V/Q ratios are partially controlled at least in low V/Q compartments since hypoxia in these compartments leads to pulmonary arteriolar vasoconstriction. However lungs V/Q ratios range from 0.1 to 10 with a mode around 1. Age, muscular exercise, posture, accelerations, anesthesia, O2 breathing, pulmonary pathology are factors which may alter the distribution of V/Q ratios. PMID:3332289

  12. Permissive hypotension does not reduce regional organ perfusion compared to normotensive resuscitation: animal study with fluorescent microspheres

    PubMed Central

    2012-01-01

    Introduction The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation. Methods Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer’s was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison. Results Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion. Conclusions Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion. PMID:23531188

  13. Brain development in childhood.

    PubMed

    Taki, Yasuyuki; Kawashima, Ryuta

    2012-01-01

    Although human brain development continues throughout childhood and adolescence, it is a non-linear process both structurally and functionally. Here we review studies of brain development in healthy children from the viewpoint of structure and the perfusion of gray and white matter. Gray matter volume increases and then decreases with age, with the developmental time of the peak volume differing among brain regions in the first and second decades of life. On the other hand, white matter volume increase is mostly linear during those periods. As regards fractional anisotropy, most regions show an exponential trajectory with aging. In addition, cerebral blood flow and gray matter volume are proportional at similar developmental ages. Moreover, we show that several lifestyle choices, such as sleeping habits and breakfast staple, affect gray matter volume in healthy children. There are a number of uninvestigated important issues that require future study. PMID:23166579

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

    PubMed

    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

  15. Intravascular Perfusion of Carbon Black Ink Allows Reliable Visualization of Cerebral Vessels

    PubMed Central

    Hasan, Mohammad R.; Herz, Josephine; Hermann, Dirk M.; Doeppner, Thorsten R.

    2013-01-01

    The anatomical structure of cerebral vessels is a key determinant for brain hemodynamics as well as the severity of injury following ischemic insults. The cerebral vasculature dynamically responds to various pathophysiological states and it exhibits considerable differences between strains and under conditions of genetic manipulations. Essentially, a reliable technique for intracranial vessel staining is essential in order to study the pathogenesis of ischemic stroke. Until recently, a set of different techniques has been employed to visualize the cerebral vasculature including injection of low viscosity resin, araldite F, gelatin mixed with various dyes1 (i.e. carmine red, India ink) or latex with2 or without3 carbon black. Perfusion of white latex compound through the ascending aorta has been first reported by Coyle and Jokelainen3. Maeda et al.2 have modified the protocol by adding carbon black ink to the latex compound for improved contrast visualization of the vessels after saline perfusion of the brain. However, inefficient perfusion and inadequate filling of the vessels are frequently experienced due to high viscosity of the latex compound4. Therefore, we have described a simple and cost-effective technique using a mixture of two commercially available carbon black inks (CB1 and CB2) to visualize the cerebral vasculature in a reproducible manner5. We have shown that perfusion with CB1+CB2 in mice results in staining of significantly smaller cerebral vessels at a higher density in comparison to latex perfusion5. Here, we describe our protocol to identify the anastomotic points between the anterior (ACA) and middle cerebral arteries (MCA) to study vessel variations in mice with different genetic backgrounds. Finally, we demonstrate the feasibility of our technique in a transient focal cerebral ischemia model in mice by combining CB1+CB2-mediated vessel staining with TTC staining in various degrees of ischemic injuries. PMID:23328838

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

    PubMed

    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

  17. GPU-accelerated voxelwise hepatic perfusion quantification.

    PubMed

    Wang, H; Cao, Y

    2012-09-01

    Voxelwise quantification of hepatic perfusion parameters from dynamic contrast enhanced (DCE) imaging greatly contributes to assessment of liver function in response to radiation therapy. However, the efficiency of the estimation of hepatic perfusion parameters voxel-by-voxel in the whole liver using a dual-input single-compartment model requires substantial improvement for routine clinical applications. In this paper, we utilize the parallel computation power of a graphics processing unit (GPU) to accelerate the computation, while maintaining the same accuracy as the conventional method. Using compute unified device architecture-GPU, the hepatic perfusion computations over multiple voxels are run across the GPU blocks concurrently but independently. At each voxel, nonlinear least-squares fitting the time series of the liver DCE data to the compartmental model is distributed to multiple threads in a block, and the computations of different time points are performed simultaneously and synchronically. An efficient fast Fourier transform in a block is also developed for the convolution computation in the model. The GPU computations of the voxel-by-voxel hepatic perfusion images are compared with ones by the CPU using the simulated DCE data and the experimental DCE MR images from patients. The computation speed is improved by 30 times using a NVIDIA Tesla C2050 GPU compared to a 2.67 GHz Intel Xeon CPU processor. To obtain liver perfusion maps with 626 400 voxels in a patient's liver, it takes 0.9 min with the GPU-accelerated voxelwise computation, compared to 110 min with the CPU, while both methods result in perfusion parameters differences less than 10(-6). The method will be useful for generating liver perfusion images in clinical settings. PMID:22892645

  18. FATTY ACID CHAIN-ELONGATION IN PERFUSED RAT HEART: SYNTHESIS OF STEAROYLCARNITINE FROM PERFUSED PALMITATE

    PubMed Central

    Kerner, Janos; Minkler, Paul E.; Lesnefsky, Edward J.; Hoppel, Charles L.

    2009-01-01

    Rat hearts perfused for up to 60 min in the working mode with palmitate, but not with glucose, resulted in substantial formation of palmitoylcarnitine and stearoylcarnitine. To test whether lipolysis of endogenous lipids was responsible for the increased stearoylcarnitine content or whether some of the perfused palmitate underwent chain elongation, hearts were perfused with hexadecanoic-16,16,16-d3 acid (M+3). The pentafluorophenacyl ester of deuterium labeled stearoylcarnitine had an M+3 (639.4 m/z) compared to the unlabeled M+0 (636.3 m/z) consistent with a direct chain elongation of the perfused palmitate. Furthermore, the near equal isotope enrichment of palmitoyl- (90.2 ± 5.8 %) and stearoylcarnitine (78.0 ± 7.1 %) suggest that both palmitoyl- and stearoyl-CoA have ready access to mitochondrial carnitine palmitoyltransferase and that most of the stearoylcarnitine is derived from the perfused palmitate. PMID:17761175

  19. Pulmonary perfusion during anesthesia and mechanical ventilation.

    PubMed

    Hedenstierna, G

    2005-06-01

    Cardiac output and the pulmonary perfusion can be affected by anesthesia and by mechanical ventilation. The changes contribute to impeded oxygenation of the blood. The major determinant of perfusion distribution in the lung is the relation between alveolar and pulmonary capillary pressures. Perfusion increases down the lung, due to hydrostatic forces. Since atelectasis is located in dependent lung regions, perfusion of non-ventilated lung parenchyma is common, producing shunt of around 8-10% of cardiac output. In addition, non-gravitational inhomogeneity of perfusion, that can be greater than the gravitational inhomogeneity, adds to impeded oxygenation of blood. Essentially all anaesthetics exert some, although mild, cardiodepressant action with one exception, ketamine. Ketamine may also increase pulmonary artery pressure, whereas other agents have little effect on pulmonary vascular tone. Mechanical ventilation impedes venous return and pushes blood flow downwards to dependent lung regions, and the effect may be striking with higher levels of PEEP. During one-lung anesthesia, there is shunt blood flow both in the non-ventilated and the ventilated lung, and shunt can be much larger in the ventilated lung than thought of. Recruitment manoeuvres shall be directed to the ventilated lung and other physical and pharmacological measures can be taken to manipulate blood flow in one lung anesthesia. PMID:15886595

  20. The cadaveric perfusion and angiography as a teaching tool: imaging the intracranial vasculature in cadavers.

    PubMed

    Turkoglu, Erhan; Seckin, Hakan; Gurer, Bora; Ahmed, Azam; Uluc, Kutluay; Pulfer, Kari; Arat, Anıl; Niemann, David; Baskaya, Mustafa K

    2014-12-01

    Background and Study Aim To enhance the visualization of the intracranial vasculature of cadavers under gross examination with a combination of imaging modalities. Material and Methods A total of 20 cadaver heads were used to test two different perfusion techniques. First, fixed cadaver heads were perfused with water; second, fresh cadavers were perfused with saline and 10% formalin. Subsequently, brains were removed and fixed. The compounds used were silicone rubber, silicone rubber mixed with powdered barium sulfate, and silicone rubber mixed with tantalum dioxide prepared by the first perfusion technique and gelatin mixed with liquid barium prepared with the second technique. Conventional X-ray imaging, computed tomography (CT), dynamic computed tomography (dCT), and postprocessing three-dimensional (3D) images were used to evaluate all the heads. Results Gelatinized barium was better visualized when compared with tantalum dioxide in conventional X-ray images. The blood vessels injected with either tantalum dioxide or gelatinized barium demonstrated a higher enhancement than the surrounding soft tissues with CT or dCT. The quality of the 3D reconstruction of the intracranial vasculature was significantly better in the CT images obtained from the gelatinized barium group. Conclusions Radiologic examinations of the heads injected with gelatinized barium facilitates the 3D understanding of cerebrovascular anatomy as an important tool for neuroanatomy training. PMID:25452903

  1. The Cadaveric Perfusion and Angiography as a Teaching Tool: Imaging the Intracranial Vasculature in Cadavers

    PubMed Central

    Turkoglu, Erhan; Seckin, Hakan; Gurer, Bora; Ahmed, Azam; Uluc, Kutluay; Pulfer, Kari; Arat, Anıl; Niemann, David; Baskaya, Mustafa K.

    2014-01-01

    Background and Study Aim To enhance the visualization of the intracranial vasculature of cadavers under gross examination with a combination of imaging modalities. Material and Methods A total of 20 cadaver heads were used to test two different perfusion techniques. First, fixed cadaver heads were perfused with water; second, fresh cadavers were perfused with saline and 10% formalin. Subsequently, brains were removed and fixed. The compounds used were silicone rubber, silicone rubber mixed with powdered barium sulfate, and silicone rubber mixed with tantalum dioxide prepared by the first perfusion technique and gelatin mixed with liquid barium prepared with the second technique. Conventional X-ray imaging, computed tomography (CT), dynamic computed tomography (dCT), and postprocessing three-dimensional (3D) images were used to evaluate all the heads. Results Gelatinized barium was better visualized when compared with tantalum dioxide in conventional X-ray images. The blood vessels injected with either tantalum dioxide or gelatinized barium demonstrated a higher enhancement than the surrounding soft tissues with CT or dCT. The quality of the 3D reconstruction of the intracranial vasculature was significantly better in the CT images obtained from the gelatinized barium group. Conclusions Radiologic examinations of the heads injected with gelatinized barium facilitates the 3D understanding of cerebrovascular anatomy as an important tool for neuroanatomy training. PMID:25452903

  2. Altered Brain Response to Drinking Glucose and Fructose in Obese Adolescents.

    PubMed

    Jastreboff, Ania M; Sinha, Rajita; Arora, Jagriti; Giannini, Cosimo; Kubat, Jessica; Malik, Saima; Van Name, Michelle A; Santoro, Nicola; Savoye, Mary; Duran, Elvira J; Pierpont, Bridget; Cline, Gary; Constable, R Todd; Sherwin, Robert S; Caprio, Sonia

    2016-07-01

    Increased sugar-sweetened beverage consumption has been linked to higher rates of obesity. Using functional MRI, we assessed brain perfusion responses to drinking two commonly consumed monosaccharides, glucose and fructose, in obese and lean adolescents. Marked differences were observed. In response to drinking glucose, obese adolescents exhibited decreased brain perfusion in brain regions involved in executive function (prefrontal cortex [PFC]) and increased perfusion in homeostatic appetite regions of the brain (hypothalamus). Conversely, in response to drinking glucose, lean adolescents demonstrated increased PFC brain perfusion and no change in perfusion in the hypothalamus. In addition, obese adolescents demonstrated attenuated suppression of serum acyl-ghrelin and increased circulating insulin level after glucose ingestion; furthermore, the change in acyl-ghrelin and insulin levels after both glucose and fructose ingestion was associated with increased hypothalamic, thalamic, and hippocampal blood flow in obese relative to lean adolescents. Additionally, in all subjects there was greater perfusion in the ventral striatum with fructose relative to glucose ingestion. Finally, reduced connectivity between executive, homeostatic, and hedonic brain regions was observed in obese adolescents. These data demonstrate that obese adolescents have impaired prefrontal executive control responses to drinking glucose and fructose, while their homeostatic and hedonic responses appear to be heightened. Thus, obesity-related brain adaptations to glucose and fructose consumption in obese adolescents may contribute to excessive consumption of glucose and fructose, thereby promoting further weight gain. PMID:27207544

  3. Cardiac tissue engineering using perfusion bioreactor systems

    PubMed Central

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  4. Perfusion and ventilation of isolated canine lungs

    PubMed Central

    Otto, T. J.; Trenkner, M.; Stopczyk, A.; Gawdziński, M.; Chełstowska, B.

    1968-01-01

    In order to evaluate methods of preserving lungs for use in transplantation, experiments on 28 mongrel dogs were carried out. Two methods were tried—first, mechanical respiration of isolated lungs under deep hypothermia, with the vascular bed filled with blood; and, secondly, the perfusion of isolated lungs with the aid of a modified DeWall's apparatus. Allogenic transplantations of lungs preserved in both ways were carried out. Gasometric and histological examinations of preserved lungs, before and after transplantation, were performed. The best results were obtained with perfusion under hypothermic conditions; ventilation without perfusion resulted in failure. Lung transplantation was successful when, after being preserved, the lung remained unchanged. Major discrepancies between the macroscopic and microscopic findings in preserved lungs were observed. An original classification of the changes occurring in preserved lungs is proposed. PMID:4886091

  5. Perfusion in Britain: the early days.

    PubMed

    Braimbridge, Mark V

    2004-07-01

    Experimental perfusion was largely the province of Germany in the nineteenth century but in the mid-twentieth century the focus of perfusion switched to the USA with the explosive clinical advances of Lillehei, Kirklin and Cooley. British clinical perfusion started with Melrose in 1953 at the Postgraduate Medical School in London but, as in other centres at that time, stopped due to the high mortality. The arrival of hands-on experience of American expertise via returning research fellows and other visitors to the USA enabled the first successful on-going series to begin at the Hammersmith Hospital with Cleland in 1957 and then to spread around the country. The various problems of those early 1950s days are described in the units starting then. PMID:15376765

  6. Myocardial perfusion scintigraphy: the evidence.

    PubMed

    Underwood, S R; Anagnostopoulos, C; Cerqueira, M; Ell, P J; Flint, E J; Harbinson, M; Kelion, A D; Al-Mohammad, A; Prvulovich, E M; Shaw, L J; Tweddel, A C

    2004-02-01

    This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by

  7. In-vivo Fluorescent X-ray CT Imaging of Mouse Brain

    SciTech Connect

    Takeda, T.; Wu, J.; Lwin, Thet-Thet; Huo, Q.; Minami, M.; Sunaguchi, N.; Murakami, T.; Mouri, S.; Nasukawa, S.; Yuasa, T.; Akatsuka, T.; Hyodo, K.; Hontani, H.

    2007-01-19

    Using a non-radioactive iodine-127 labeled cerebral perfusion agent (I-127 IMP), fluorescent X-ray computed tomography (FXCT) clearly revealed the cross-sectional distribution of I-127 IMP in normal mouse brain in-vivo. Cerebral perfusion of cortex and basal ganglion was depicted with 1 mm in-plane spatial resolution and 0.1 mm slice thickness. Degree of cerebral perfusion in basal ganglion was about 2-fold higher than that in cortical regions. This result suggests that in-vivo cerebral perfusion imaging is realized quantitatively by FXCT at high volumetric resolution.

  8. Effects of laser acupuncture on blood perfusion rate

    NASA Astrophysics Data System (ADS)

    Wang, Xian-ju; Zeng, Chang-chun; Liu, Han-ping; Liu, Song-hao; Liu, Liang-gang

    2006-09-01

    Based on Pennes equation, the influences of the intensity and the impulse frequency of laser acupuncture on the point tissues' blood flow perfusion rate are discussed. We find that the blood perfusion rate of point tissue increases with the intensity of laser acupuncture increasing. After impulse laser acupuncture the point tissue blood perfusion rate increase little, but after continuum laser acupuncture the point tissues blood perfusion rate increase much.

  9. Acute toxicity of doxorubicin on isolated perfused heart: response of kinases regulating energy supply.

    PubMed

    Tokarska-Schlattner, Malgorzata; Zaugg, Michael; da Silva, Rafaela; Lucchinetti, Eliana; Schaub, Marcus C; Wallimann, Theo; Schlattner, Uwe

    2005-07-01

    Doxorubicin (DXR) is a widely used and efficient anticancer drug. However, its application is limited by the risk of severe cardiotoxicity. Impairment of cardiac high-energy phosphate homeostasis is an important manifestation of both acute and chronic DXR cardiotoxic action. Using the Langendorff model of the perfused rat heart, we characterized the acute effects of 1-h perfusion with 2 or 20 microM DXR on two key kinases in cardiac energy metabolism, creatine kinase (CK) and AMP-activated protein kinase (AMPK), and related them to functional responses of the perfused heart and structural integrity of the contractile apparatus as well as drug accumulation in cardiomyocytes. DXR-induced changes in CK were dependent on the isoenzyme, with a shift in protein levels of cytosolic isoenzymes from muscle-type CK to brain-type CK, and a destabilization of octamers of the mitochondrial isoenzyme (sarcometric mitochondrial CK) accompanied by drug accumulation in mitochondria. Interestingly, DXR rapidly reduced the protein level and phosphorylation of AMPK as well as phosphorylation of its target, acetyl-CoA-carboxylase. AMPK was strongly affected already at 2 microM DXR, even before substantial cardiac dysfunction occurred. Impairment of CK isoenzymes was mostly moderate but became significant at 20 microM DXR. Only at 2 microM DXR did upregulation of brain-type CK compensate for inactivation of other isoenzymes. These results suggest that an impairment of kinase systems regulating cellular energy homeostasis is involved in the development of DXR cardiotoxicity. PMID:15764680

  10. Three-dimensional MRI perfusion maps: a step beyond volumetric analysis in mental disorders

    PubMed Central

    Fabene, Paolo F; Farace, Paolo; Brambilla, Paolo; Andreone, Nicola; Cerini, Roberto; Pelizza, Luisa; Versace, Amelia; Rambaldelli, Gianluca; Birbaumer, Niels; Tansella, Michele; Sbarbati, Andrea

    2007-01-01

    A new type of magnetic resonance imaging analysis, based on fusion of three-dimensional reconstructions of time-to-peak parametric maps and high-resolution T1-weighted images, is proposed in order to evaluate the perfusion of selected volumes of interest. Because in recent years a wealth of data have suggested the crucial involvement of vascular alterations in mental diseases, we tested our new method on a restricted sample of schizophrenic patients and matched healthy controls. The perfusion of the whole brain was compared with that of the caudate nucleus by means of intrasubject analysis. As expected, owing to the encephalic vascular pattern, a significantly lower time-to-peak was observed in the caudate nucleus than in the whole brain in all healthy controls, indicating that the suggested method has enough sensitivity to detect subtle perfusion changes even in small volumes of interest. Interestingly, a less uniform pattern was observed in the schizophrenic patients. The latter finding needs to be replicated in an adequate number of subjects. In summary, the three-dimensional analysis method we propose has been shown to be a feasible tool for revealing subtle vascular changes both in normal subjects and in pathological conditions. PMID:17229290

  11. C-arm cone beam CT perfusion imaging using the SMART-RECON algorithm to improve temporal sampling density and temporal resolution

    NASA Astrophysics Data System (ADS)

    Li, Yinsheng; Niu, Kai; Li, Ke; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong

    2016-03-01

    In this work, a newly developed reconstruction algorithm, Synchronized MultiArtifact Reduction with Tomographic RECONstruction (SMART-RECON), was applied to C-arm cone beam CT perfusion (CBCTP) imaging. This algorithm contains a special rank regularizer, designed to reduce limited-view artifacts associated with super- short scan reconstructions. As a result, high temporal sampling and temporal resolution image reconstructions were achieved using an interventional C-arm x-ray system. The algorithm was evaluated in terms of the fidelity of the dynamic contrast update curves and the accuracy of perfusion parameters through numerical simulation studies. Results shows that, not only were the dynamic curves accurately recovered (relative root mean square error ∈ [3%, 5%] compared with [13%, 22%] for FBP), but also the noise in the final perfusion maps was dramatically reduced. Compared with filtered backprojection, SMART-RECON generated CBCTP maps with much improved capability in differentiating lesions with perfusion deficits from the surrounding healthy brain tissues.

  12. N-isopropyl-(/sup 123/I)p-iodoamphetamine: single-pass brain uptake and washout; binding to brain synaptosomes; and localization in dog and monkey brain

    SciTech Connect

    Winchell, H.S.; Horst, W.D.; Braun, L.; Oldendorf, W.H.; Hattner, R.; Parker, H.

    1980-10-01

    The kinetics of N-isopropyl-p-(/sup 123/I)iodoamphetamine in rat brains were determined by serial measurements of brain uptake index (BUI) after intracarotid injection; also studied were its effects on amine uptake and release in rat's brain cortical synaptosomes; and its in vivo distribution in the dog and monkey. No specific localization in brain nuclei of the dog was seen, but there was progressive accumulation in the eyes. Rapid initial brain uptake in the ketamine-sedated monkey was noted, and further slow brain uptake occurred during the next 20 min but without retinal localization. High levels of brain activity were maintained for several hours. The quantitative initial single-pass clearance of the agent in the brain suggests its use in evaluation of regional brain perfusion. Its interaction with brain amine-binding sites suggests its possible application in studies of cerebral amine metabolism.

  13. The prognostic value of non-perfusion variables obtained during vasodilator stress myocardial perfusion imaging.

    PubMed

    Bajaj, Navkaranbir S; Singh, Siddharth; Farag, Ayman; El-Hajj, Stephanie; Heo, Jack; Iskandrian, Ami E; Hage, Fadi G

    2016-06-01

    Myocardial perfusion imaging (MPI) is an established diagnostic test that provides useful prognostic data in patients with known or suspected coronary artery disease. In more than half of the patients referred for stress testing, vasodilator stress is used in lieu of exercise. Unlike exercise, vasodilator stress does not provide information on exercise and functional capacity, heart rate recovery, and chronotropy, and ECG changes are less frequent. These non-perfusion data provide important prognostic and patient management information. Further, event rates in patients undergoing vasodilator MPI are higher than in those undergoing exercise MPI and even in those with normal images probably due to higher pretest risk. However, there are a number of non-perfusion variables that are obtained during vasodilator stress testing, which have prognostic relevance but their use has not been well emphasized. The purpose of this review is to summarize the prognostic values of these non-perfusion data obtained during vasodilator MPI. PMID:26940574

  14. Gradient-enhanced FAWSETS perfusion measurements

    NASA Astrophysics Data System (ADS)

    Marro, Kenneth I.; Lee, Donghoon; Hyyti, Outi M.

    2005-08-01

    This work describes the use of custom-built gradients to enhance skeletal muscle perfusion measurements acquired with a previously described arterial spin labeling technique known as FAWSETS (flow-driven arterial water stimulation with elimination of tissue signal). Custom-built gradients provide active control of the static magnetic field gradient on which FAWSETS relies for labeling. This allows selective, 180° modulations of the phase of the perfusion component of the signal. Phase cycling can then be implemented to eliminate all extraneous components leaving a signal that exclusively reflects capillary-level perfusion. Gradient-enhancement substantially reduces acquisition time and eliminates the need to acquire an ischemic signal to quantify perfusion. This removes critical obstacles to application of FAWSETS in organs other than skeletal muscle and makes the measurements more desirable for clinical environments. The basic physical principles of gradient-enhancement are demonstrated in flow phantom experiments and in vivo utility is demonstrated in rat hind limb during stimulated exercise.

  15. Urate synthesis in the perfused chick liver

    PubMed Central

    Barratt, Eileen; Buttery, Peter J.; Boorman, K. Neil

    1974-01-01

    Urate synthesis was studied in a perfused chicken liver preparation. The perfused liver had an ATP/ADP ratio of 0.29±0.05(6) compared with 0.34±0.07(10) in liver obtained from chicks under ether anaesthesia. Lactate/pyruvate ratios were 9.4±1.7(5) in the perfused liver and 14.8±1.8(5) in the rapidly sampled liver. Urate synthesis was only marginally stimulated by glycine, glutamine, aspartic acid or NH4Cl, but significant increases were observed with phosphoribosyl pyrophosphate, aminoimidazolecarboxylic acid riboside, inosine, inosinic acid and xanthine. Urate synthesis from glycine, glutamine, NH4Cl, asparagine, alanine, histidine and a mixture of 21 amino acids was obtained on inclusion of insulin in the perfusion medium. Evidence for the inclusion of the carbon of histidine into uric acid was obtained. Aspects of the energy consumption associated with the conversion of excess of amino acid into uric acid are considered. PMID:4462579

  16. Automated sonographic evaluation of testicular perfusion

    NASA Astrophysics Data System (ADS)

    Thierman, Jonathan S.; Clement, Gregory T.; Kalish, Leslie A.; O'Kane, Patrick L.; Frauscher, Ferdinand; Paltiel, Harriet J.

    2006-07-01

    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the investigation of vascular disorders of the testis. We investigated the ability of two automated computer algorithms to analyse contrast-enhanced pulse inversion US data in a rabbit model of unilateral testicular ischaemia and to correctly determine relative testicular perfusion: nonlinear curve fitting of the US backscatter intensity as a function of time; and spectral analysis of the intensity time trace. We compared (i) five metrics based on the algorithmic data to testicular perfusion ratios obtained with radiolabelled microspheres, a reference standard; (ii) qualitative assessment of the US images by two independent readers blinded to the side of the experimental and control testes to the radiolabelled microsphere perfusion ratios; and (iii) results of the algorithmically-derived metrics to the qualitative assessments of the two readers. For the curve fit method, the algorithmically-derived metrics agreed with the reference standard in 54% to 68% of all cases. For the spectral method, the results agreed in 70% of all cases. The two readers agreed with the reference standard in 40% and 35% of all cases, respectively. These results suggest that automated methods of analysis may provide useful information in the assessment of testicular perfusion.

  17. Asynchronicity of Facial Blood Perfusion in Migraine

    PubMed Central

    Zaproudina, Nina; Teplov, Victor; Nippolainen, Ervin; Lipponen, Jukka A.; Kamshilin, Alexei A.; Närhi, Matti; Karjalainen, Pasi A.; Giniatullin, Rashid

    2013-01-01

    Asymmetrical changes in blood perfusion and asynchronous blood supply to head tissues likely contribute to migraine pathophysiology. Imaging was widely used in order to understand hemodynamic variations in migraine. However, mapping of blood pulsations in the face of migraineurs has not been performed so far. We used the Blood Pulsation Imaging (BPI) technique, which was recently developed in our group, to establish whether 2D-imaging of blood pulsations parameters can reveal new biomarkers of migraine. BPI characteristics were measured in migraineurs during the attack-free interval and compared to healthy subjects with and without a family history of migraine. We found a novel phenomenon of transverse waves of facial blood perfusion in migraineurs in contrast to healthy subjects who showed synchronous blood delivery to both sides of the face. Moreover, the amplitude of blood pulsations was symmetrically distributed over the face of healthy subjects, but asymmetrically in migraineurs and subjects with a family history of migraine. In the migraine patients we found a remarkable correlation between the side of unilateral headache and the direction of the blood perfusion wave. Our data suggest that migraine is associated with lateralization of blood perfusion and asynchronous blood pulsations in the facial area, which could be due to essential dysfunction of the autonomic vascular control in the face. These findings may further enhance our understanding of migraine pathophysiology and suggest new easily available biomarkers of this pathology. PMID:24324592

  18. Simplified prototyping of perfusable polystyrene microfluidics

    PubMed Central

    Tran, Reginald; Ahn, Byungwook; R. Myers, David; Qiu, Yongzhi; Sakurai, Yumiko; Moot, Robert; Mihevc, Emma; Trent Spencer, H.; Doering, Christopher; A. Lam, Wilbur

    2014-01-01

    Cell culture in microfluidic systems has primarily been conducted in devices comprised of polydimethylsiloxane (PDMS) or other elastomers. As polystyrene (PS) is the most characterized and commonly used substrate material for cell culture, microfluidic cell culture would ideally be conducted in PS-based microsystems that also enable tight control of perfusion and hydrodynamic conditions, which are especially important for culture of vascular cell types. Here, we report a simple method to prototype perfusable PS microfluidics for endothelial cell culture under flow that can be fabricated using standard lithography and wet laboratory equipment to enable stable perfusion at shear stresses up to 300 dyn/cm2 and pumping pressures up to 26 kPa for at least 100 h. This technique can also be extended to fabricate perfusable hybrid PS-PDMS microfluidics of which one application is for increased efficiency of viral transduction in non-adherent suspension cells by leveraging the high surface area to volume ratio of microfluidics and adhesion molecules that are optimized for PS substrates. These biologically compatible microfluidic devices can be made more accessible to biological-based laboratories through the outsourcing of lithography to various available microfluidic foundries. PMID:25379106

  19. Nuclear cardiology: Myocardial perfusion and function

    SciTech Connect

    Seldin, D.W. )

    1991-08-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references.

  20. SU-E-QI-06: Design and Initial Validation of a Precise Capillary Phantom to Test Perfusion Systems

    SciTech Connect

    Wood, R; Iacobucci, G; Khobragade, P; Ying, L; Snyder, K; Wack, D; Rudin, S; Ionita, C

    2014-06-15

    Purpose: To design a precise perfusion phantom mimicking capillaries of the brain vasculature which could be used to test various perfusion protocols and algorithms which generate perfusion maps. Methods: A perfusion phantom was designed in Solidworks and built using additive manufacturing. The phantom was an overall cylindrical shape of diameter and height 20mm and containing capillaries of 200μm or 300μm which were parallel and in contact making up the inside volume where flow was allowed. We created a flow loop using a peristaltic pump and contrast agent was injected manually. Digital Subtraction Angiographic images and low contrast images with cone beam CT were acquired after the contrast was injected. These images were analyzed by our own code in LabVIEW software and Time-Density Curve, MTT and TTP was calculated. Results: Perfused area was visible in the cone beam CT images; however, individual capillaries were not distinguishable. The Time-Density Curve acquired was accurate, sensitive and repeatable. The parameters MTT, and TTP offered by the phantom were very sensitive to slight changes in the TDC shape. Conclusion: We have created a robust calibrating model for evaluation of existing perfusion data analysis systems. This approach is extremely sensitive to changes in the flow due to the high temporal resolution and could be used as a golden standard to assist developers in calibrating and testing of imaging perfusion systems and software algorithms. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.

  1. Brain Science, Brain Fiction.

    ERIC Educational Resources Information Center

    Bruer, John T.

    1998-01-01

    Three big ideas from brain science have arisen during the past 20 to 30 years: neural connections form rapidly early in life; critical periods occur in development; and enriched environments profoundly affect brain development during the early years. Current brain research has little to offer educational practice or policy. (10 references) (MLH)

  2. A metabolic index of ischemic injury for perfusion-recovery of cadaveric rat livers.

    PubMed

    Perk, Sinem; Izamis, Maria-Louisa; Tolboom, Herman; Uygun, Basak; Berthiaume, Francois; Yarmush, Martin L; Uygun, Korkut

    2011-01-01

    With over 110,000 patients waiting for organ transplantation, the current crisis in organ transplantation is based on a lack of donors after brain-death (DBD). A very large alternative pool of donor organs that remain untapped are the donors after cardiac death (DCD), recovered after cardiac activity has ceased and therefore sustained some ischemic injury. Machine perfusion has been proposed as a novel modality of organ preservation and treatment to render such cadaveric organs, and in particular livers, transplantable. Two key issues that remain unaddressed are how to assess whether a DCD liver is damaged beyond repair, and whether machine perfusion has rendered an injured organ sufficiently viable for transplantation. In this work, we present a metabolic analysis of the transient responses of cadaveric rat livers during normothermic machine perfusion (NMP), and develop an index of ischemia that enables evaluation of the organ ischemic injury level. Further, we perform a discriminant analysis to construct a classification algorithm with >0.98 specificity to identify whether a given perfused liver is ischemic or fresh, in effect a precursor for an index of transplantability and a basis for the use of statistical process control measures for automated feedback control of treatment of ischemic injury in DCD livers. The analyses yield an index based on squared prediction error (SPE) as log(SPE) >1.35 indicating ischemia. The differences between metabolic functions of fresh and ischemic livers during perfusion are outlined and the metabolites that varied significantly for ischemic livers are identified as ornithine, arginine, albumin and tyrosine. PMID:22194843

  3. The impact of age on cerebral perfusion, oxygenation and metabolism during exercise in humans.

    PubMed

    Braz, Igor D; Fisher, James P

    2016-08-15

    Age is one of the most important risk factors for dementia and stroke. Examination of the cerebral circulatory responses to acute exercise in the elderly may help to pinpoint the mechanisms by which exercise training can reduce the risk of brain diseases, inform the optimization of exercise training programmes and assist with the identification of age-related alterations in cerebral vascular function. During low-to-moderate intensity dynamic exercise, enhanced neuronal activity is accompanied by cerebral perfusion increases of ∼10-30%. Beyond ∼60-70% maximal oxygen uptake, cerebral metabolism remains elevated but perfusion in the anterior portion of the circulation returns towards baseline, substantively because of a hyperventilation-mediated reduction in the partial pressure of arterial carbon dioxide (P aC O2) and cerebral vasoconstriction. Cerebral perfusion is lower in older individuals, both at rest and during incremental dynamic exercise. Nevertheless, the increase in the estimated cerebral metabolic rate for oxygen and the arterial-internal jugular venous differences for glucose and lactate are similar in young and older individuals exercising at the same relative exercise intensities. Correction for the age-related reduction in P aC O2 during exercise by the provision of supplementary CO2 is suggested to remove ∼50% of the difference in cerebral perfusion between young and older individuals. A multitude of candidates could account for the remaining difference, including cerebral atrophy, and enhanced vasoconstrictor and blunted vasodilatory pathways. In summary, age-related reductions in cerebral perfusion during exercise are partly associated with a lower P aC O2 in exercising older individuals; nevertheless the cerebral extraction of glucose, lactate and oxygen appear to be preserved. PMID:26435295

  4. A Metabolic Index of Ischemic Injury for Perfusion-Recovery of Cadaveric Rat Livers

    PubMed Central

    Tolboom, Herman; Uygun, Basak; Berthiaume, Francois; Yarmush, Martin L.; Uygun, Korkut

    2011-01-01

    With over 110,000 patients waiting for organ transplantation, the current crisis in organ transplantation is based on a lack of donors after brain-death (DBD). A very large alternative pool of donor organs that remain untapped are the donors after cardiac death (DCD), recovered after cardiac activity has ceased and therefore sustained some ischemic injury. Machine perfusion has been proposed as a novel modality of organ preservation and treatment to render such cadaveric organs, and in particular livers, transplantable. Two key issues that remain unaddressed are how to assess whether a DCD liver is damaged beyond repair, and whether machine perfusion has rendered an injured organ sufficiently viable for transplantation. In this work, we present a metabolic analysis of the transient responses of cadaveric rat livers during normothermic machine perfusion (NMP), and develop an index of ischemia that enables evaluation of the organ ischemic injury level. Further, we perform a discriminant analysis to construct a classification algorithm with >0.98 specificity to identify whether a given perfused liver is ischemic or fresh, in effect a precursor for an index of transplantability and a basis for the use of statistical process control measures for automated feedback control of treatment of ischemic injury in DCD livers. The analyses yield an index based on squared prediction error (SPE) as log(SPE) >1.35 indicating ischemia. The differences between metabolic functions of fresh and ischemic livers during perfusion are outlined and the metabolites that varied significantly for ischemic livers are identified as ornithine, arginine, albumin and tyrosine. PMID:22194843

  5. Comparing Normothermic Machine Perfusion Preservation With Different Perfusates on Porcine Livers From Donors After Circulatory Death.

    PubMed

    Liu, Q; Nassar, A; Farias, K; Buccini, L; Mangino, M J; Baldwin, W; Bennett, A; O'Rourke, C; Iuppa, G; Soliman, B G; Urcuyo-Llanes, D; Okamoto, T; Uso, T D; Fung, J; Abu-Elmagd, K; Miller, C; Quintini, C

    2016-03-01

    The utilization of normothermic machine perfusion (NMP) may be an effective strategy to resuscitate livers from donation after circulatory death (DCD). There is no consensus regarding the efficacy of different perfusates on graft and bile duct viability. The aim of this study was to compare, in an NMP porcine DCD model, the preservation potential of three different perfusates. Twenty porcine livers with 60 min of warm ischemia were separated into four preservation groups: cold storage (CS), NMP with Steen solution (Steen; XVIVO Perfusion Inc., Denver, CO), Steen plus red blood cells (RBCs), or whole blood (WB). All livers were preserved for 10 h and reperfused to simulate transplantation for 24 h. During preservation, the NMP with Steen group presented the highest hepatocellular injury. At reperfusion, the CS group had the lowest bile production and the worst hepatocellular injury compared with all other groups, followed by NMP with Steen; the Steen plus RBC and WB groups presented the best functional and hepatocellular injury outcomes, with WB livers showing lower aspartate aminotransferase release and a trend toward better results for most parameters. Based on our results, a perfusate that contains an oxygen carrier is most effective in a model of NMP porcine DCD livers compared with Steen solution. Specifically, WB-perfused livers showed a trend toward better outcomes compared with Steen plus RBCs. PMID:26663737

  6. SU-E-I-36: A KWIC and Dirty Look at Dose Savings and Perfusion Metrics in Simulated CT Neuro Perfusion Exams

    SciTech Connect

    Hoffman, J; Martin, T; Young, S; McNitt-Gray, M; Wang, D

    2015-06-15

    Purpose: CT neuro perfusion scans are one of the highest dose exams. Methods to reduce dose include decreasing the number of projections acquired per gantry rotation, however conventional reconstruction of such scans leads to sampling artifacts. In this study we investigated a projection view-sharing reconstruction algorithm used in dynamic MRI – “K-space Weighted Image Contrast” (KWIC) – applied to simulated perfusion exams and evaluated dose savings and impacts on perfusion metrics. Methods: A FORBILD head phantom containing simulated time-varying objects was developed and a set of parallel-beam CT projection data was created. The simulated scans were 60 seconds long, 1152 projections per turn, with a rotation time of one second. No noise was simulated. 5mm, 10mm, and 50mm objects were modeled in the brain. A baseline, “full dose” simulation used all projections and reduced dose cases were simulated by downsampling the number of projections per turn from 1152 to 576 (50% dose), 288 (25% dose), and 144 (12.5% dose). KWIC was further evaluated at 72 projections per rotation (6.25%). One image per second was reconstructed using filtered backprojection (FBP) and KWIC. KWIC reconstructions utilized view cores of 36, 72, 144, and 288 views and 16, 8, 4, and 2 subapertures respectively. From the reconstructed images, time-to-peak (TTP), cerebral blood flow (CBF) and the FWHM of the perfusion curve were calculated and compared against reference values from the full-dose FBP data. Results: TTP, CBF, and the FWHM were unaffected by dose reduction (to 12.5%) and reconstruction method, however image quality was improved when using KWIC. Conclusion: This pilot study suggests that KWIC preserves image quality and perfusion metrics when under-sampling projections and that the unique contrast weighting of KWIC could provided substantial dose-savings for perfusion CT scans. Evaluation of KWIC in clinical CT data will be performed in the near future. R01 EB014922, NCI

  7. Using Flat-Panel Perfusion Imaging to Measure Cerebral Hemodynamics

    PubMed Central

    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

    2016-01-01

    Abstract 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

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

    PubMed Central

    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 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 <3 h) ischemic stroke. Most of the patients underwent admission multimodal CT, and all patients had follow-up NCCT at 24 h. ASPECTS was assigned to all modalities and correlated with clinical and imaging parameters. Receiver-operating characteristic curve analysis was performed to determine optimal thresholds for different parameters to predict clinical outcome. 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

  9. Selective cerebro-myocardial perfusion in complex congenital aortic arch pathology: a novel technique.

    PubMed

    De Rita, Fabrizio; Lucchese, Gianluca; Barozzi, Luca; Menon, Tiziano; Faggian, Giuseppe; Mazzucco, Alessandro; Luciani, Giovanni Battista

    2011-11-01

    Simultaneous cerebro-myocardial perfusion has been described in neonatal and infant arch surgery, suggesting a reduction in cardiac morbidity. Here reported is a novel technique for selective cerebral perfusion combined with controlled and independent myocardial perfusion during surgery for complex or recurrent aortic arch lesions. From April 2008 to April 2011, 10 patients with arch pathology underwent surgery (two hypoplastic left heart syndrome [HLHS], four recurrent arch obstruction, two aortic arch hypoplasia + ventricular septal defect [VSD], one single ventricle + transposition of the great arteries + arch hypoplasia, one interrupted aortic arch type B + VSD). Median age was 63 days (6 days-36 years) and median weight 4.0 kg (1.6-52). Via midline sternotomy, an arterial cannula (6 or 8 Fr for infants) was directly inserted into the innominate artery or through a polytetrafluoroethylene (PTFE) graft (for neonates <2.0 kg). A cardioplegia delivery system was inserted into the aortic root. Under moderate hypothermia, ascending and descending aorta were cross-clamped, and "beating heart and brain" aortic arch repair was performed. Arch repair was composed of patch augmentation in five, end-to-side anastomosis in three, and replacement in two patients. Average cardiopulmonary bypass time was 163 ± 68 min (71-310). In two patients only (one HLHS, one complex single ventricle), a period of cardiac arrest was required to complete intracardiac repair. In such cases, antegrade blood cardioplegia was delivered directly via the same catheter used for selective myocardial perfusion. Average time of splanchnic ischemia during cerebro-myocardial perfusion was 39 ± 18 min (17-69). Weaning from cardiopulmonary bypass was achieved without inotropic support in three and with low dose in seven patients. One patient required veno-arterial extracorporeal membrane oxygenation. Four patients, body weight <3.0 kg, needed delayed sternal closure. No neurologic dysfunction was noted

  10. Early Time Points Perfusion Imaging

    PubMed Central

    Kwong, Kenneth K.; Reese, Timothy G.; Nelissen, Koen; Wu, Ona; Chan, Suk-Tak; Benner, Thomas; Mandeville, Joseph B.; Foley, Mary; Vanduffel, Wim; Chesler, David A.

    2010-01-01

    The aim was to investigate the feasibility of making relative cerebral blood flow (rCBF) maps from MR images acquired with short TR by measuring the initial arrival amount of Gd-DTPA evaluated within a time window before any contrast agent has a chance to leave the tissue. We named this rCBF measurement technique utilizing the early data points of the Gd-DTPA bolus the “early time points” method (ET), based on the hypothesis that early time point signals were proportional to rCBF. Simulation data were used successfully to examine the ideal behavior of ET while monkey’s MRI results offered encouraging support to the utility of ET for rCBF calculation. A better brain coverage for ET could be obtained by applying the Simultaneous Echo Refocusing (SER) EPI technique. A recipe to run ET was presented, with attention paid to the noise problem around the time of arrival (TOA) of the contrast agent. PMID:20851196

  11. Clinical Neuroimaging Using Arterial Spin-Labeled Perfusion MRI

    PubMed Central

    Wolf, Ronald L.; Detre, John A.

    2007-01-01

    SUMMARY The two most common methods for measuring perfusion with MRI are based on dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL). Although clinical experience to date is much more extensive with DSC perfusion MRI, ASL methods offer several advantages. The primary advantages are that completely noninvasive absolute cerebral blood flow (CBF) measurements are possible with relative insensitivity to permeability, and that multiple repeated measurements can be obtained to evaluate one or more interventions or to perform perfusion-based functional MRI. ASL perfusion and perfusion-based fMRI methods have been applied in many clinical settings, including acute and chronic cerebrovascular disease, CNS neoplasms, epilepsy, aging and development, neurodegenerative disorders, and neuropsychiatric diseases. Recent technical advances have improved the sensitivity of ASL perfusion MRI, and increasing use is expected in the coming years. This review focuses on ASL perfusion MRI and applications in clinical neuroimaging. PMID:17599701

  12. [Increased intracranial pressure and brain edema].

    PubMed

    Dietrich, W; Erbguth, F

    2013-03-01

    In primary and secondary brain diseases, increasing volumes of the three compartments of brain tissue, cerebrospinal fluid, or blood lead to a critical increase in intracranial pressure (ICP). A rising ICP is associated with typical clinical symptoms; however, during analgosedation it can only be detected by invasive ICP monitoring. Other neuromonitoring procedures are not as effective as ICP monitoring; they reflect the ICP changes and their complications by other metabolic and oxygenation parameters. The most relevant parameter for brain perfusion is cerebral perfusion pressure (CPP), which is calculated as the difference between the middle arterial pressure (MAP) and the ICP. A mixed body of evidence exists for the different ICP-reducing treatment measures, such as hyperventilation, hyperosmolar substances, hypothermia, glucocorticosteroids, CSF drainage, and decompressive surgery. PMID:23503630

  13. [Increased intracranial pressure and brain edema].

    PubMed

    Dietrich, W; Erbguth, F

    2013-09-01

    In primary and secondary brain diseases, increasing volumes of the three compartments of brain tissue, cerebrospinal fluid, or blood lead to a critical increase in intracranial pressure (ICP). A rising ICP is associated with typical clinical symptoms; however, during analgosedation it can only be detected by invasive ICP monitoring. Other neuromonitoring procedures are not as effective as ICP monitoring; they reflect the ICP changes and their complications by other metabolic and oxygenation parameters. The most relevant parameter for brain perfusion is cerebral perfusion pressure (CPP), which is calculated as the difference between the middle arterial pressure (MAP) and the ICP. A mixed body of evidence exists for the different ICP-reducing treatment measures, such as hyperventilation, hyperosmolar substances, hypothermia, glucocorticosteroids, CSF drainage, and decompressive surgery. PMID:24061872

  14. Multi-modality imaging for the assessment of myocardial perfusion with emphasis on stress perfusion CT and MR imaging.

    PubMed

    Ko, Sung Min; Hwang, Hweung Kon; Kim, Sung Mok; Cho, Ihn Ho

    2015-06-01

    High-quality and non-invasive diagnostic tools for assessing myocardial ischemia are necessary for therapeutic decisions regarding coronary artery disease. Myocardial perfusion has been studied using myocardial contrast echo perfusion, single-photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and, more recently, computed tomography. The addition of coronary computed tomography angiography to myocardial perfusion imaging improves the specificity and overall diagnostic accuracy of detecting the hemodynamic significance of coronary artery stenosis. This study reviews the benefits, limitations, and imaging findings of various imaging modalities for assessing myocardial perfusion, with particular emphasis on stress perfusion computed tomography and cardiovascular magnetic resonance imaging. PMID:25809387

  15. Brain herniation

    MedlinePlus

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  16. Hyperosmolar opening of the blood-brain barrier in the energy-depleted rat brain. Part 1. Permeability studies

    SciTech Connect

    Greenwood, J.; Luthert, P.J.; Pratt, O.E.; Lantos, P.L.

    1988-02-01

    A simple saline perfusion system was used to investigate the effects of hyperosmolar solutions of arabinose and mannitol upon the permeability of the blood-brain barrier. The small, polar molecule (/sup 14/C)mannitol and the larger, visual marker Evans blue were used as indicators of barrier integrity in the perfused energy-depleted brain. One-minute perfusion of hyperosmolar solutions consistently opened the barrier suggesting that the mechanism of osmotic barrier opening is independent of energy-producing metabolism. The accumulation of radiolabel in the brain was expressed as the ratio of tissue to perfusate radioactivity (Rt/Rp) and, for cerebrum, this increased from a control value of 0.0022 +/- 0.0007 (mean +/- SEM; n = 4) to a value of 0.0124 +/- 0.0008 (n = 4) following 0.9 M arabinose and to 0.0495 +/- 0.0072 (n = 4) following 1.8 M arabinose. There was a significant reduction of water content of hyperosmolar perfused brains. These findings support the hypothesis that osmotic barrier opening is the result of the passive shrinkage of endothelial cells and the surrounding tissue.

  17. Luminal perfusion of isolated gastric glands.

    PubMed

    Waisbren, S J; Geibel, J; Boron, W F; Modlin, I M

    1994-04-01

    We have extended to rabbit gastric glands the technique for perfusing single isolated renal tubules. We isolated glands by hand dissection and used concentric glass pipettes to hold them and perfuse their lumina. Parietal cells (PCs), which tended to be located toward the gland opening, were identified by their pyramidal shape, large size, and autofluorescence. Chief cells (CCs) were identified by their round shape and smaller size. In some experiments, we perfused the lumen with hydroxypyrenetrisulfonate, a pH-sensitive fluorophore, at pH 7.4 and used digital image processing to monitor luminal pH (pH1). Solutions were buffered with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid to pH 7.4 at 37 degrees C. With fast perfusion, we found no evidence of decreased pH1, even with stimulation by 10 microM carbachol. With slow perfusion, pH1 often fell below the dye's sensitive range (pH < 5), especially at low perfusate buffering power. In other experiments, we loaded cells with the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein and monitored intracellular pH (pHi) in multiple individual PCs and CCs in a single gland. Mean pHi was 7.21 +/- 0.02 (n = 136 cells) for PCs and 7.27 +/- 0.03 (n = 103) for CCs. To examine the response to decreased pH1 and basolateral pH (pHb), we lowered pHb to 6.4 or lowered pH1 to 3.4 or 1.4. Lowering pHb to 6.4 for approximately 1 min caused pHi to fall reversibly by 0.39 +/- 0.05 (n = 53) in PCs and 0.58 +/- 0.03 (n = 50) in CCs. Lowering pH1 to 3.4 or 1.4 caused no significant pHi changes in PCs (n = 38 and 82) or in CCs (n = 44 and 77). Carbachol did not affect the response to changes in pH1 or pHb. We conclude that the apical surfaces of PCs and CCs are unusually resistant to extreme pH gradients. PMID:8178950

  18. Perfusion techniques for minimally invasive valve procedures.

    PubMed

    de Jong, A; Popa, B A; Stelian, E; Karazanishvili, L; Lanzillo, G; Simonini, S; Renzi, L; Diena, M; Tesler, U F

    2015-05-01

    In this paper, we present, in detail, the simplified perfusion technique that we have adopted since January 2009 and that we have utilized in 200 cases for cardiac minimally invasive valvular procedures that were performed through a right lateral mini-thoracotomy in the 3(rd)-4(th) intercostal space. Cardiopulmonary bypass was achieved by means of the direct cannulation of the ascending aorta and the insertion of a percutaneous venous cannula in the femoral vein. A flexible aortic cross-clamp was applied through the skin incision and cardioplegic arrest was obtained with the antegrade delivery of a crystalloid solution. Gravity drainage was enhanced by vacuum-assisted aspiration. There were no technical complications related to this perfusion technique that we have adopted in minimally invasive surgical procedures. PMID:25280878

  19. Assessment of cerebral perfusion in childhood strokes

    SciTech Connect

    Gates, G.F.; Fishman, L.S.; Segall, H.D.

    1982-11-01

    Thirty-three children who had strokes were studied by dynamic and static scintigraphy, 29 by CT scanning, and 10 by cerebral angiography. The accuracy of dynamic scintigraphy in stroke detection during the first week of clinical symptoms was 94% while CT scanning was 60% accurate and static scintigraphy 11% accurate. During the second week the accuracy of CT scanning increased to 100%, but static scintigraphy improved to only 50%. Fifty percent of scintiangiograms performed during the first week showed either luxuriant perfusion or flip-flop patterns. In some patients these two flow patterns changed to that of cerebral hemispheric ischemia after going through a phase during which perfusion appeared to be equal in the two hemispheres. Dynamic scintigraphy is believed to be the test of choice for stroke detection in children during the first week.

  20. Gluconeogenesis in the perfused rat liver.

    PubMed

    Hems, R; Ross, B D; Berry, M N; Krebs, H A

    1966-11-01

    1. A modification of the methods of Miller and of Schimassek for the perfusion of the isolated rat liver, suitable for the study of gluconeogenesis, is described. 2. The main modifications concern the operative technique (reducing the period of anoxia during the operation to 3min.) and the use of aged (non-glycolysing) red cells in the semi-synthetic perfusion medium. 3. The performance of the perfused liver was tested by measuring the rate of gluconeogenesis, of urea synthesis and the stability of adenine nucleotides. Higher rates of gluconeogenesis (1mumole/min./g.) from excess of lactate and of urea synthesis from excess of ammonia (4mumoles/min./g. in the presence of ornithine) were observed than are likely to occur in vivo where rates are limited by the rate of supply of precursor. The concentrations of the three adenine nucleotides in the liver tissue were maintained within 15% over a perfusion period of 135min. 4. Ca(2+), Na(+), K(+), Mg(2+) and phosphate were found to be required at physiological concentrations for optimum gluconeogenesis but bicarbonate and carbon dioxide could be largely replaced by phosphate buffer without affecting the rate of gluconeogenesis. 5. Maximal gluconeogenesis did not decrease maximal urea synthesis in the presence of ornithine and ammonia and vice versa. This indicates that the energy requirements were not limiting the rates of gluconeogenesis or of urea synthesis. 6. Addition of lactate, and especially ammonium salts, increased the uptake of oxygen more than expected on the basis of the ATP requirements of the gluconeogenesis and urea synthesis. PMID:5966267

  1. Dynamic CT perfusion measurement in a cardiac phantom.

    PubMed

    Ziemer, Benjamin P; Hubbard, Logan; Lipinski, Jerry; Molloi, Sabee

    2015-10-01

    Widespread clinical implementation of dynamic CT myocardial perfusion has been hampered by its limited accuracy and high radiation dose. The purpose of this study was to evaluate the accuracy and radiation dose reduction of a dynamic CT myocardial perfusion technique based on first pass analysis (FPA). To test the FPA technique, a pulsatile pump was used to generate known perfusion rates in a range of 0.96-2.49 mL/min/g. All the known perfusion rates were determined using an ultrasonic flow probe and the known mass of the perfusion volume. FPA and maximum slope model (MSM) perfusion rates were measured using volume scans acquired from a 320-slice CT scanner, and then compared to the known perfusion rates. The measured perfusion using FPA (P(FPA)), with two volume scans, and the maximum slope model (P(MSM)) were related to known perfusion (P(K)) by P(FPA) = 0.91P(K) + 0.06 (r = 0.98) and P(MSM) = 0.25P(K) - 0.02 (r = 0.96), respectively. The standard error of estimate for the FPA technique, using two volume scans, and the MSM was 0.14 and 0.30 mL/min/g, respectively. The estimated radiation dose required for the FPA technique with two volume scans and the MSM was 2.6 and 11.7-17.5 mSv, respectively. Therefore, the FPA technique can yield accurate perfusion measurements using as few as two volume scans, corresponding to approximately a factor of four reductions in radiation dose as compared with the currently available MSM. In conclusion, the results of the study indicate that the FPA technique can make accurate dynamic CT perfusion measurements over a range of clinically relevant perfusion rates, while substantially reducing radiation dose, as compared to currently available dynamic CT perfusion techniques. PMID:26156231

  2. Multitracer study in Heidenhain variant of Creutzfeldt-Jakob disease: mismatch pattern of cerebral hypometabolism and perfusion imaging.

    PubMed

    Pichler, Robert; Ciovica, Ioana; Rachinger, Johanna; Weiss, Serge; Aichner, Franz T

    2008-02-01

    Creutzfeldt-Jakob disease (CJD) is a subacute spongiform encephalopathy. This fatal prion disease is characterized by rapidly progressive dementia with a variety of neurological disorders. Diagnostic methods provided by nuclear medicine might be helpful for evaluation of patients with probable CJD as additional diagnostic tools to MRI and cerebro-spinal fluid evaluation. The experience with FDG-PET and brain perfusion SPECT is presented. PMID:18283251

  3. Inhomogeneity of pulmonary perfusion during sustained microgravity

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; West, John B.

    1994-01-01

    The effects of gravity on the inhomogeneity of pulmonary perfusion in man were studied by performing hyperventilation-breathhold single-breath measurements before, during and after 9 days of continuous exposure to microgravity. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase 4, were both markedly reduced. Cardiogenic oscillations were reduced to approximately 60 of their preflight standing size, while the height of phase 4 was between 0 and -8% (a terminal fall became a small terminal rise) of preflights standing. The terminal change in CO2 was nearly abolished in microgravity indicating more uniformity of blood flow between lung units that close at the end of expiration and units that remain open. This may result from the disappearance of gravity-dependent topographical inequality of blood flow. The residual cardiographic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity at a level larger than acinar.

  4. Regulation of skeletal muscle perfusion during exercise

    NASA Technical Reports Server (NTRS)

    Delp, M. D.; Laughlin, M. H.

    1998-01-01

    For exercise to be sustained, it is essential that adequate blood flow be provided to skeletal muscle. The local vascular control mechanisms involved in regulating muscle perfusion during exercise include metabolic control, endothelium-mediated control, propagated responses, myogenic control, and the muscle pump. The primary determinant of muscle perfusion during sustained exercise is the metabolic rate of the muscle. Metabolites from contracting muscle diffuse to resistance arterioles and act directly to induce vasodilation, or indirectly to inhibit noradrenaline release from sympathetic nerve endings and oppose alpha-adrenoreceptor-mediated vasoconstriction. The vascular endothelium also releases vasodilator substances (e.g., prostacyclin and nitric oxide) that are prominent in establishing basal vascular tone, but these substances do not appear to contribute to the exercise hyperemia in muscle. Endothelial and smooth muscle cells may also be involved in propagating vasodilator signals along arterioles to parent and daughter vessels. Myogenic autoregulation does not appear to be involved in the exercise hyperemia in muscle, but the rhythmic propulsion of blood from skeletal muscle veins facilitates venous return to the heart and muscle perfusion. It appears that the primary determinants of sustained exercise hyperemia in skeletal muscle are metabolic vasodilation and increased vascular conductance via the muscle pump. Additionally, sympathetic neural control is important in regulating muscle blood flow during exercise.

  5. Perfusion computed tomography in renal cell carcinoma.

    PubMed

    Das, Chandan J; Thingujam, Usha; Panda, Ananya; Sharma, Sanjay; Gupta, Arun Kumar

    2015-07-28

    Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma (RCC). While contrast enhanced computed tomography (CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT (pCT), goes down to the molecular level and provides new perspectives in imaging of RCC. pCT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using pCT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of pCT in staging and response assessment in patients with RCCs. PMID:26217456

  6. Noncontact blood perfusion mapping in clinical applications

    NASA Astrophysics Data System (ADS)

    Iakovlev, Dmitry; Dwyer, Vincent; Hu, Sijung; Silberschmidt, Vadim

    2016-04-01

    Non-contact imaging photoplethysmography (iPPG) to detect pulsatile blood microcirculation in tissue has been selected as a successor to low spatial resolution and slow scanning blood perfusion techniques currently employed by clinicians. The proposed iPPG system employs a novel illumination source constructed of multiple high power LEDs with narrow spectral emission, which are temporally modulated and synchronised with a high performance sCMOS sensor. To ensure spectrum stability and prevent thermal wavelength drift due to junction temperature variations, each LED features a custom-designed thermal management system to effectively dissipate generated heat and auto-adjust current flow. The use of a multi-wavelength approach has resulted in simultaneous microvascular perfusion monitoring at various tissue depths, which is an added benefit for specific clinical applications. A synchronous detection algorithm to extract weak photoplethysmographic pulse-waveforms demonstrated robustness and high efficiency when applied to even small regions of 5 mm2. The experimental results showed evidences that the proposed system could achieve noticeable accuracy in blood perfusion monitoring by creating complex amplitude and phase maps for the tissue under examination.

  7. [Brain metastases imaging].

    PubMed

    Delmaire, C; Savatovsky, J; Boulanger, T; Dhermain, F; Le Rhun, E; Météllus, P; Gerber, S; Carsin-Nicole, B; Petyt, G

    2015-02-01

    The therapeutic management of brain metastases depends upon their diagnosis and characteristics. It is therefore imperative that imaging provides accurate diagnosis, identification, size and localization information of intracranial lesions in patients with presumed cerebral metastatic disease. MRI exhibits superior sensitivity to CT for small lesions identification and to evaluate their precise anatomical location. The CT-scan will be made only in case of MRI's contraindication or if MRI cannot be obtained in an acceptable delay for the management of the patient. In clinical practice, the radiologic metastasis evaluation is based on visual image analyses. Thus, a particular attention is paid to the imaging protocol with the aim to optimize the diagnosis of small lesions and to evaluate their evolution. The MRI protocol must include: 1) non-contrast T1, 2) diffusion, 3) T2* or susceptibility-weighted imaging, 4) dynamic susceptibility contrast perfusion, 5) FLAIR with contrast injection, 6) T1 with contrast injection preferentially using the 3D spin echo images. The role of the nuclear medicine imaging is still limited in the diagnosis of brain metastasis. The Tc-sestamibi brain imaging or PET with amino acid tracers can differentiate local brain metastasis recurrence from radionecrosis but still to be evaluated. PMID:25649387

  8. Diagnosis of brain death

    PubMed Central

    Machado, Calixto

    2010-01-01

    Brain death (BD) should be understood as the ultimate clinical expression of a brain catastrophe characterized by a complete and irreversible neurological stoppage, recognized by irreversible coma, absent brainstem reflexes, and apnea. The most common pattern is manifested by an elevation of intracranial pressure to a point beyond the mean arterial pressure, and hence cerebral perfusion pressure falls and, as a result, no net cerebral blood flow is present, in due course leading to permanent cytotoxic injury of the intracranial neuronal tissue. A second mechanism is an intrinsic injury affecting the nervous tissue at a cellular level which, if extensive and unremitting, can also lead to BD. We review here the methodology of diagnosing death, based on finding any of the signs of death. The irreversible loss of cardio-circulatory and respiratory functions can cause death only when ischemia and anoxia are prolonged enough to produce an irreversible destruction of the brain. The sign of such loss of brain functions, that is to say BD diagnosis, is fully reviewed. PMID:21577338

  9. Dynamic subcortical blood flow during male sexual activity with ecological validity: a perfusion fMRI study.

    PubMed

    Georgiadis, Janniko R; Farrell, Michael J; Boessen, Ruud; Denton, Derek A; Gavrilescu, Maria; Kortekaas, Rudie; Renken, Remco J; Hoogduin, Johannes M; Egan, Gary F

    2010-03-01

    This study used arterial spin labeling (ASL) fMRI to measure brain perfusion in a group of healthy men under conditions that closely resembled customary sexual behavior. Serial perfusion measures for 30 min during two self-limited periods of partnered penis stimulation, and during post-stimulatory periods, revealed novel sexual activity-related cerebral blood flow (rCBF) changes, mainly in subcortical parts of the brain. Ventral pallidum rCBF was highest during the onset of penile erection, and lowest after the termination of penis stimulation. The perceived level of sexual arousal showed the strongest positive association with rCBF in the right basal forebrain. In addition, our results demonstrate that distinct subregions of the hypothalamus and cingulate cortex subserve opposite functions during human male sexual behavior. The lateral hypothalamus and anterior part of the middle cingulate cortex showed increased rCBF correlated with penile erection. By contrast, the anteroventral hypothalamus and subgenual anterior cingulate cortex exhibited rCBF changes correlated with penile detumescence after penile stimulation. Continuous rapid and high-resolution brain perfusion imaging during normal sexual activity has provided novel insights into the central mechanisms that control male sexual arousal. PMID:20006720

  10. Review of diagnostic uses of shunt fraction quantification with technetium-99m macroaggregated albumin perfusion scan as illustrated by a case of Osler–Weber–Rendu syndrome

    PubMed Central

    Chokkappan, Kabilan; Kannivelu, Anbalagan; Srinivasan, Sivasubramanian; Babut, Suresh Balasubramanian

    2016-01-01

    Bilateral pulmonary arteriovenous malformations (AVMs) are rare and are often associated with the hereditary hemorrhagic telangiectasia (HHT/Osler–Weber–Rendu) syndrome. We present a woman who presented with neurological symptoms due to a cerebral abscess. On further evaluation, bilateral pulmonary AVMs were identified. The patient was diagnosed with HHT, based on positive family history and multiple cerebral AVMs recognized on subsequent catheter angiogram, in addition to the presence of bilateral pulmonary AVMs. Craniotomy with drainage of the brain abscess and endovascular embolization of the pulmonary AVMs was offered to the patient. As a preembolization work-up, the patient underwent nuclear lung perfusion scan with technetium-99m macroaggregated albumin (Tc-99m MAA) to assess the right-to-left shunt secondary to the pulmonary AVMs. Postembolization follow-up perfusion scan was also obtained to estimate the hemodynamic response. The case is presented to describe the role of Tc-99m MAA perfusion lung scan in preoperatively evaluating patients with pulmonary AVMs and to emphasize on the scan's utility in posttreatment follow-up. Various present day usages of the Tc-99m MAA lung perfusion scan, other than diagnosing pulmonary thromboembolism, are discussed. Providing background knowledge on the physiological and hemodynamic aspects of the Tc-99m MAA lung perfusion scan is also attempted. Various imaging pitfalls and necessary precautions while performing Tc-99m MAA lung perfusion scan are highlighted. PMID:27168866

  11. Review of diagnostic uses of shunt fraction quantification with technetium-99m macroaggregated albumin perfusion scan as illustrated by a case of Osler-Weber-Rendu syndrome.

    PubMed

    Chokkappan, Kabilan; Kannivelu, Anbalagan; Srinivasan, Sivasubramanian; Babut, Suresh Balasubramanian

    2016-01-01

    Bilateral pulmonary arteriovenous malformations (AVMs) are rare and are often associated with the hereditary hemorrhagic telangiectasia (HHT/Osler-Weber-Rendu) syndrome. We present a woman who presented with neurological symptoms due to a cerebral abscess. On further evaluation, bilateral pulmonary AVMs were identified. The patient was diagnosed with HHT, based on positive family history and multiple cerebral AVMs recognized on subsequent catheter angiogram, in addition to the presence of bilateral pulmonary AVMs. Craniotomy with drainage of the brain abscess and endovascular embolization of the pulmonary AVMs was offered to the patient. As a preembolization work-up, the patient underwent nuclear lung perfusion scan with technetium-99m macroaggregated albumin (Tc-99m MAA) to assess the right-to-left shunt secondary to the pulmonary AVMs. Postembolization follow-up perfusion scan was also obtained to estimate the hemodynamic response. The case is presented to describe the role of Tc-99m MAA perfusion lung scan in preoperatively evaluating patients with pulmonary AVMs and to emphasize on the scan's utility in posttreatment follow-up. Various present day usages of the Tc-99m MAA lung perfusion scan, other than diagnosing pulmonary thromboembolism, are discussed. Providing background knowledge on the physiological and hemodynamic aspects of the Tc-99m MAA lung perfusion scan is also attempted. Various imaging pitfalls and necessary precautions while performing Tc-99m MAA lung perfusion scan are highlighted. PMID:27168866

  12. CT Perfusion Dynamics of Intracranial Tuberculomas

    PubMed Central

    N., Jayakumar Peruvumba; Shivashankar, Ravishankar

    2015-01-01

    Aims To study perfusion characteristics of intracranial tuberculomas and analyze changes with anti tubercular treatment. Materials and Methods Nineteen patients of histologically proven intracranial tuberculomas were included in the study of which 9 were not on antitubercular treatment and ten were on antitubercular treatment (6 patients on treatment for less than 2 months and 4 were more than 6 months). All patients underwent CT perfusion (CTP) and CTP parameters like rCBV and rCBF were obtained from entire lesion, center and capsule of lesions and compared. Results CTP parameters like rCBF and rCBV were significantly low in all the three ROIs in the group not on treatment compared to that of on treatment ; rCBF and rCBV of entire lesion (p=0.018 and p=0.005 respectively), capsule (p=0.045 and p=0.010 respectively) and center of the lesion (p=0.020 and p=0.009) respectively). Tuberculomas on antitubercular treatment of more than six months showed reduced rCBF and rCBV in entire lesion (p=0.01 & p=0.01 respectively), capsule (p=0.04 & p=0.03 respectively) and center (p=0.08 & p=0.05 respectively) compared to those on treatment for less than two months. Similarly tuberculomas on treatment for six months did not show significant difference in rCBF and rCBV compared to tuberculomas who were not on treatment. Tuberculomas on treatment for less than two months showed statistically increased rCBF and rCBV in entire lesion (p=0.01 & p=0.04 respectively), capsule (p=0.03 & p=0.01 respectively) and center (p= 0.03 &=0.01) compared to those not on treatment. Conclusion Intracranial tuberculomas not on treatment and those on treatment for around six months show low perfusion and tuberculomas on treatment for less than two months show high perfusion. These findings suggest that serial perfusion profiles of tuberculomas on treatment could possibly be seen as surrogate markers of response to treatment. PMID:26155528

  13. [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].

    PubMed

    Hirano, Keiko; Fukuda, Tokiko

    2016-05-01

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

  14. Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

    PubMed Central

    Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

    2012-01-01

    Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

  15. Measurement of cerebrospinal fluid formation and absorption by ventriculo-cisternal perfusion: what is really measured?

    PubMed Central

    Orešković, Darko; Klarica, Marijan

    2014-01-01

    The generally accepted hypothesis on cerebrospinal fluid (CSF) hydrodynamics suggests that CSF is actively formed mainly by choroid plexuses, circulates unidirectionally along the brain ventricles and subarachnoid space, and is passively absorbed mainly into the dural venous sinuses. CSF formation rate (Vf) has been extensively studied using the ventriculo-cisternal perfusion technique and the results have been used as the key evidence confirming the mentioned hypothesis. This method and the equation for Vf calculation are based on the assumption that the dilution of the indicator substance is a consequence of the newly formed CSF, ie, that a higher CSF formation rate will result in a higher degree of dilution. However, it has been experimentally shown that the indicator substance dilution inside the CSF system does not occur because of a “newly formed” CSF, but as consequence of a number of other factors (departure of substances into the surrounding tissue, flowing around the collecting cannula into the cortical and spinal subarachnoid space, departure into the contralateral ventricle, etc). This technique allows “calculation” of the CSF formation even in dead animals, in an in vitro model, and in any other part of the CSF system outside the ventricles that is being perfused. Therefore, this method is indirect and any dilution of the indicator substance in the perfusate caused by other reasons would result in questionable and often contradictory conclusions regarding CSF formation rates. PMID:25165046

  16. A Phantom Tissue System for the Calibration of Perfusion Measurements

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Scott, Elaine P.; Diller, Thomas E.

    2008-01-01

    A convenient method for testing and calibrating surface perfusion sensors has been developed. A phantom tissue model is used to simulate the nondirectional blood flow of tissue perfusion. A computational fluid dynamics (CFD) model was constructed in Fluent® to design the phantom tissue and validate the experimental results. The phantom perfusion system was used with a perfusion sensor based on clearance of thermal energy. A heat flux gage measures the heat flux response of tissue when a thermal event (convective cooling) is applied. The blood perfusion and contact resistance are estimated by a parameter estimation code. From the experimental and analytical results, it was concluded that the probe displayed good measurement repeatability and sensitivity. The experimental perfusion measurements in the tissue were in good agreement with those of the CFD models and demonstrated the value of the phantom tissue system. PMID:19045509

  17. Cerebral extracellular lactate increase is predominantly nonischemic in patients with severe traumatic brain injury

    PubMed Central

    Sala, Nathalie; Suys, Tamarah; Zerlauth, Jean-Baptiste; Bouzat, Pierre; Messerer, Mahmoud; Bloch, Jocelyne; Levivier, Marc; Magistretti, Pierre J; Meuli, Reto; Oddo, Mauro

    2013-01-01

    Growing evidence suggests that endogenous lactate is an important substrate for neurons. This study aimed to examine cerebral lactate metabolism and its relationship with brain perfusion in patients with severe traumatic brain injury (TBI). A prospective cohort of 24 patients with severe TBI monitored with cerebral microdialysis (CMD) and brain tissue oxygen tension (PbtO2) was studied. Brain lactate metabolism was assessed by quantification of elevated CMD lactate samples (>4 mmol/L); these were matched to CMD pyruvate and PbtO2 values and dichotomized as glycolytic (CMD pyruvate >119 μmol/L vs. low pyruvate) and hypoxic (PbtO2 <20 mm Hg vs. nonhypoxic). Using perfusion computed tomography (CT), brain perfusion was categorized as oligemic, normal, or hyperemic, and was compared with CMD and PbtO2 data. Samples with elevated CMD lactate were frequently observed (41±8%), and we found that brain lactate elevations were predominantly associated with glycolysis and normal PbtO2 (73±8%) rather than brain hypoxia (14±6%). Furthermore, glycolytic lactate was always associated with normal or hyperemic brain perfusion, whereas all episodes with hypoxic lactate were associated with diffuse oligemia. Our findings suggest predominant nonischemic cerebral extracellular lactate release after TBI and support the concept that lactate may be used as an energy substrate by the injured human brain. PMID:23963367

  18. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  19. Scintigraphic perfusion patterns in patients with diffuse lung disease

    SciTech Connect

    Newman, G.E.; Sullivan, D.C.; Gottschalk, A.; Putman, C.E.

    1982-04-01

    Perfusion scintigrams of 55 patients with radiographic evidence of diffuse lung disease were reviewed. Thirty-nine had acute and/or chronic changes caused by congestive heart failure, and 16 had diffuse reticulonodular disease. A normal or near-normal perfusion pattern was seen in 40/55 (73%), and this finding was equally common in the two groups. The authors conclude that perfusion scintigraphy is useful in excluding pulmonary embolism in patients with radiographic evidence of diffuse, symmetrical lung disease.

  20. A method of thymic perfusion and its evaluation

    PubMed Central

    Ekwueme, O.

    1973-01-01

    The development and evaluation of a method of isolated ex vivo perfusion of the rabbit thymus using diluted autologous blood is described. The data indicate that the viability of the preparation is maintained at a satisfactory level during the period of perfusion. These results suggest that the isolated perfused thymus would be a useful new approach to studies of thymus function. ImagesFig. 2Fig. 8Fig. 9Fig. 10Fig. 11 PMID:4747584

  1. Perfusion Scintigraphy and Patient Selection for Lung Volume Reduction Surgery

    PubMed Central

    Chandra, Divay; Lipson, David A.; Hoffman, Eric A.; Hansen-Flaschen, John; Sciurba, Frank C.; DeCamp, Malcolm M.; Reilly, John J.; Washko, George R.

    2010-01-01

    Rationale: It is unclear if lung perfusion can predict response to lung volume reduction surgery (LVRS). Objectives: To study the role of perfusion scintigraphy in patient selection for LVRS. Methods: We performed an intention-to-treat analysis of 1,045 of 1,218 patients enrolled in the National Emphysema Treatment Trial who were non–high risk for LVRS and had complete perfusion scintigraphy results at baseline. The median follow-up was 6.0 years. Patients were classified as having upper or non–upper lobe–predominant emphysema on visual examination of the chest computed tomography and high or low exercise capacity on cardiopulmonary exercise testing at baseline. Low upper zone perfusion was defined as less than 20% of total lung perfusion distributed to the upper third of both lungs as measured on perfusion scintigraphy. Measurements and Main Results: Among 284 of 1,045 patients with upper lobe–predominant emphysema and low exercise capacity at baseline, the 202 with low upper zone perfusion had lower mortality with LVRS versus medical management (risk ratio [RR], 0.56; P = 0.008) unlike the remaining 82 with high perfusion where mortality was unchanged (RR, 0.97; P = 0.62). Similarly, among 404 of 1,045 patients with upper lobe–predominant emphysema and high exercise capacity, the 278 with low upper zone perfusion had lower mortality with LVRS (RR, 0.70; P = 0.02) unlike the remaining 126 with high perfusion (RR, 1.05; P = 1.00). Among the 357 patients with non–upper lobe–predominant emphysema (75 with low and 282 with high exercise capacity) there was no improvement in survival with LVRS and measurement of upper zone perfusion did not contribute new prognostic information. Conclusions: Compared with optimal medical management, LVRS reduces mortality in patients with upper lobe–predominant emphysema when there is low rather than high perfusion to the upper lung. PMID:20538961

  2. Brain vascular and hydrodynamic physiology

    PubMed Central

    Tasker, Robert C.

    2013-01-01

    Protecting the brain in vulnerable infants undergoing surgery is a central aspect of perioperative care. Understanding the link between blood flow, oxygen delivery and oxygen consumption leads to a more informed approach to bedside care. In some cases, we need to consider how high can we let the partial pressure of carbon dioxide go before we have concerns about risk of increased cerebral blood volume and change in intracranial hydrodynamics? Alternatively, in almost all such cases, we have to address the question of how low can we let the blood pressure drop before we should be concerned about brain perfusion? This review, provides a basic understanding of brain bioenergetics, hemodynamics, hydrodynamics, autoregulation and vascular homeostasis to changes in blood gases that is fundamental to our thinking about bedside care and monitoring. PMID:24331089

  3. Tbx1 regulates brain vascularization.

    PubMed

    Cioffi, Sara; Martucciello, Stefania; Fulcoli, Filomena Gabriella; Bilio, Marchesa; Ferrentino, Rosa; Nusco, Edoardo; Illingworth, Elizabeth

    2014-01-01

    The transcription factor TBX1 is the major gene involved in 22q11.2 deletion syndrome (22q11.2DS). Using mouse models of these diseases, we have previously shown that TBX1 activates VEGFR3 in endothelial cells (EC), and that this interaction is critical for the development of the lymphatic vasculature. In this study, we show that TBX1 regulates brain angiogenesis. Using loss-of-function genetics and molecular approaches, we show that TBX1 regulates the VEGFR3 and DLL4 genes in brain ECs. In mice, loss of TBX1 causes global brain vascular defects, comprising brain vessel hyperplasia, enhanced angiogenic sprouting and vessel network disorganization. This phenotype is recapitulated in EC-specific Tbx1 conditional mutants and in an EC-only 3-dimensional cell culture system (matrigel), indicating that the brain vascular phenotype is cell autonomous. Furthermore, EC-specific conditional Tbx1 mutants have poorly perfused brain vessels and brain hypoxia, indicating that the expanded vascular network is functionally impaired. In EC-matrigel cultures, a Notch1 agonist is able to partially rescue microtubule hyperbranching induced by TBX1 knockdown. Thus, we have identified a novel transcriptional regulator of angiogenesis that exerts its effect in brain by negatively regulating angiogenesis through the DLL4/Notch1-VEGFR3 regulatory axis. Given the similarity of the phenotypic consequences of TBX1 mutation in humans and mice, this unexpected role of TBX1 in murine brain vascularization should stimulate clinicians to search for brain microvascular anomalies in 22q11.2DS patients and to evaluate whether some of the anatomical and functional brain anomalies in patients may have a microvascular origin. PMID:23945394

  4. Extracorporeal Free Flap Perfusion in Case of Prolonged Ischemia Time

    PubMed Central

    Präbst, K.; Beier, J. P.; Meyer, A.; Horch, R. E.

    2016-01-01

    Summary: In free flap surgery, a clinically established concept still has to be found for the reduction of ischemia-related cell damage in the case of prolonged ischemia. Although promising results using extracorporeal free flap perfusion in the laboratory have been published in the past, until now this concept has not yet paved its way into clinical routine. This might be due to the complexity of perfusion systems and a lack of standardized tools. Here, we want to present the results of the first extracorporeal free flap perfusion in a clinical setting using a simple approach without the application of a complex perfusion machinery. PMID:27200244

  5. New imaging technology: measurement of myocardial perfusion by contrast echocardiography

    NASA Technical Reports Server (NTRS)

    Rubin, D. N.; Thomas, J. D.

    2000-01-01

    Myocardial perfusion imaging has long been a goal for the non-invasive echocardiographic assessment of the heart. However, many factors at play in perfusion imaging have made this goal elusive. Harmonic imaging and triggered imaging with newer contrast agents have made myocardial perfusion imaging potentially practical in the very near future. The application of indicator dilution theory to the coronary circulation and bubble contrast agents is fraught with complexities and sources of error. Therefore, quantification of myocardial perfusion by non-invasive echocardiographic imaging requires further investigation in order to make this technique clinically viable.

  6. Perfusion CT imaging of the liver: review of clinical applications

    PubMed Central

    Oğul, Hayri; Kantarcı, Mecit; Genç, Berhan; Pirimoğlu, Berhan; Çullu, Neşat; Kızrak, Yeşim; Yılmaz, Ömer; Karabulut, Nevzat

    2014-01-01

    Perfusion computed tomography (CT) has a great potential for determining hepatic and portal blood flow; it offers the advantages of quantitative determination of lesion hemodynamics, distinguishing malignant and benign processes, as well as providing morphological data. Many studies have reported the use of this method in the assessment of hepatic tumors, hepatic fibrosis associated with chronic liver disease, treatment response following radiotherapy and chemotherapy, and hepatic perfusion changes after radiological or surgical interventions. The main goal of liver perfusion imaging is to improve the accuracy in the characterization of liver disorders. In this study, we reviewed the clinical application of perfusion CT in various hepatic diseases. PMID:24834487

  7. Radionuclide Tracers for Myocardial Perfusion Imaging and Blood Flow Quantification.

    PubMed

    deKemp, Robert A; Renaud, Jennifer M; Klein, Ran; Beanlands, Rob S B

    2016-02-01

    Myocardial perfusion imaging is performed most commonly using Tc-99m-sestamibi or tetrofosmin SPECT as well as Rb-82-rubidium or N-13-ammonia PET. Diseased-to-normal tissue contrast is determined by the tracer retention fraction, which decreases nonlinearly with flow. Reduced tissue perfusion results in reduced tracer retention, but the severity of perfusion defects is typically underestimated by 20% to 40%. Compared to SPECT, retention of the PET tracers is more linearly related to flow, and therefore, the perfusion defects are measured more accurately using N-13-ammonia or Rb-82. PMID:26590778

  8. The effects of perfusion conditions on melphalan distribution in the isolated perfused rat hindlimb bearing a human melanoma xenograft.

    PubMed

    Wu, Z Y; Smithers, B M; Parsons, P G; Roberts, M S

    1997-01-01

    An isolated rat hindlimb perfusion model carrying xenografts of the human melanoma cell line MM96 was used to study the effects of perfusion conditions on melphalan distribution. Krebs-Henseleit buffer and Hartmann's solution containing 4.7% bovine serum albumin (BSA) or 2.8% dextran 40 were used as perfusates. Melphalan concentrations in perfusate, tumour nodules and normal tissues were measured using high-performance liquid chromatography (HPLC). Increasing the perfusion flow rates (from 4 to 8 ml min(-1)) resulted in higher tissue blood flow (determined with 51Cr-labelled microspheres) and melphalan uptake by tumour and normal tissues. The distribution of melphalan within tumour nodules and normal tissues was similar for both Krebs-Henseleit buffer and Hartmann's solution; however, tissue concentrations of melphalan were significantly higher for a perfusate containing 2.8% dextran 40 than for one containing 4.7% BSA. The melphalan concentration in the tumour was one-third of that found in the skin if the perfusate contained 4.7% BSA. In conclusion, this study has shown that a high perfusion flow enhances the delivery of melphalan into implanted tumour nodules and normal tissues, and a perfusate with low melphalan binding (no albumin) is preferred for maximum uptake of drug by the tumour. PMID:9099965

  9. Voxel-level comparison of arterial spin-labeled perfusion magnetic resonance imaging in adolescents with internet gaming addiction

    PubMed Central

    2013-01-01

    Background Although recent studies have clearly demonstrated functional and structural abnormalities in adolescents with internet gaming addiction (IGA), less is known about how IGA affects perfusion in the human brain. We used pseudocontinuous arterial spin-labeling (ASL) perfusion functional magnetic resonance imaging (fMRI) to measure the effects of IGA on resting brain functions by comparing resting cerebral blood flow in adolescents with IGA and normal subjects. Methods Fifteen adolescents with IGA and 18 matched normal adolescents underwent structural and perfusion fMRI in the resting state. Direct subtraction, voxel-wise general linear modeling was performed to compare resting cerebral blood flow (CBF) between the 2 groups. Correlations were calculated between the mean CBF value in all clusters that survived AlphaSim correction and the Chen Internet Addiction Scale (CIAS) scores, Barratt Impulsiveness Scale-11 (BIS-11) scores, or hours of Internet use per week (hours) in the 15 subjects with IGA. Results Compared with control subjects, adolescents with IGA showed significantly higher global CBF in the left inferior temporal lobe/fusiform gyrus, left parahippocampal gyrus/amygdala, right medial frontal lobe/anterior cingulate cortex, left insula, right insula, right middle temporal gyrus, right precentral gyrus, left supplementary motor area, left cingulate gyrus, and right inferior parietal lobe. Lower CBF was found in the left middle temporal gyrus, left middle occipital gyrus, and right cingulate gyrus. There were no significant correlations between mean CBF values in all clusters that survived AlphaSim correction and CIAS or BIS-11 scores or hours of Internet use per week. Conclusions In this study, we used ASL perfusion fMRI and noninvasively quantified resting CBF to demonstrate that IGA alters the CBF distribution in the adolescent brain. The results support the hypothesis that IGA is a behavioral addiction that may share similar neurobiological

  10. Experimental glomerulonephritis in the isolated perfused rat kidney.

    PubMed Central

    Couser, W G; Steinmuller, D R; Stilmant, M M; Salant, D J; Lowenstein, L M

    1978-01-01

    The development of immune deposits on the subepithelial surface of the glomerular capillary wall was studied in isolated rat kidneys perfused at controlled perfusion pressure, pH, temperature, and flow rates with recirculating oxygenated perfusate containing bovine serum albumin (BSA) in buffer and sheep antibody to rat proximal tubular epithelial cell brush border antigen (Fx1A). Control kidney were perfused with equal concentrations of non-antibody immunoglobulin (Ig)G. Renal function was monitored by measuring inulin clearance, sodium reabsorption, and urine flow as well as BSA excretion and fractional clearance. Perfused kidneys were studied by light, immunofluorescence, and electron microscopy. All kidneys perfused with anti-Fx1A developed diffuse, finely granular deposits of IgG along the glomerular capillary wall by immunofluorescence. Electron microscopy revealed these deposits to be localized exclusively in the subepithelial space and slit pores. Similar deposits were produced in a nonrecirculating perfusion system, thereby excluding the formation of immune complexes in the perfusate caused by renal release of tubular antigen. Control kidneys perfused with nonantibody IgG did not develop glomerular immune deposits. Renal function and BSA excretion were the same in experimental and control kidneys. Glomerular deposits in antibody perfused kidneys were indistinguishable from deposits in rats injected with anti-Fx1A or immunized with Fx1A to produce autologous immune complex nephropathy. These studies demonstrate that subepithelial immune deposits can be produced in the isolated rat kidney by perfusion with specific antibody to Fx1A in the absence of circulating immune complexes. In this model deposits result from in situ complex formation rather than circulating immune complex deposition. Images PMID:372233

  11. Perfusion single photon emission computed tomography in a mouse model of neurofibromatosis type 1: towards a biomarker of neurologic deficits.

    PubMed

    Apostolova, Ivayla; Niedzielska, Dagmara; Derlin, Thorsten; Koziolek, Eva J; Amthauer, Holger; Salmen, Benedikt; Pahnke, Jens; Brenner, Winfried; Mautner, Victor F; Buchert, Ralph

    2015-08-01

    Neurofibromatosis type 1 (NF1) is a single-gene disorder affecting neurologic function in humans. The NF1+/- mouse model with germline mutation of the NF1 gene presents with deficits in learning, attention, and motor coordination, very similar to NF1 patients. The present study performed brain perfusion single-photon emission computed tomography (SPECT) in NF1+/- mice to identify possible perfusion differences as surrogate marker for altered cerebral activity in NF1. Cerebral perfusion was measured with hexamethyl-propyleneamine oxime (HMPAO) SPECT in NF1+/- mice and their wild-type littermates longitudinally at juvenile age and at young adulthood. Histology and immunohistochemistry were performed to test for structural changes. There was increased HMPAO uptake in NF1 mice in the amygdala at juvenile age, which reduced to normal levels at young adulthood. There was no genotype effect on thalamic HMPAO uptake, which was confirmed by ex vivo measurements of F-18-fluorodeoxyglucose uptake in the thalamus. Morphologic analyses showed no major structural abnormalities. However, there was some evidence of increased density of microglial somata in the amygdala of NF1-deficient mice. In conclusion, there is evidence of increased perfusion and increased density of microglia in juvenile NF1 mice specifically in the amygdala, both of which might be associated with altered synaptic plasticity and, therefore, with cognitive deficits in NF1. PMID:25785829

  12. Brain Tumors

    MedlinePlus

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  13. Feasibility of Using Pseudo-Continuous Arterial Spin Labeling Perfusion in a Geriatric Population at 1.5 Tesla

    PubMed Central

    Sigurdsson, Sigurdur; Forsberg, Lars; Aspelund, Thor; van der Geest, Rob J.; van Buchem, Mark A.; Launer, Lenore J.; Gudnason, Vilmundur; van Osch, Matthias J.

    2015-01-01

    Objectives To evaluate the feasibility of using pseudo-continuous arterial spin labeling (pCASL) perfusion in a geriatric population at 1.5-Tesla. Materials and Methods In 17 participants (mean age 78.8±1.63 years) we assessed; 1) inter-session repeatability and reliability of resting state perfusion in 27 brain regions; 2) brain activation using finger-tapping as a means to evaluate the ability to detect flow differences; 3) reliability by comparing cerebral blood flow (CBF) with pCASL to CBF with phase contrast (PC-MR). Results The CBF (mean±standard deviation (SD)) for the whole brain grey matter (GM) was 40.6±8.4 and 41.4±8.7 ml/100g/min for the first and second scan respectively. The within-subject standard deviation (SDw), the repeatability index (RI) and intra-class correlation coefficient (ICC) across the 27 regions ranged from 1.1 to 7.9, 2.2 to 15.5 and 0.35 to 0.98 respectively. For whole brain GM the SDw, RI and ICC were 1.6, 3.2 and 0.96 respectively. The between-subject standard deviation (SDB) was larger than the SDw for all regions. Comparison of CBF at rest and activation on a voxel level showed significantly higher perfusion during finger tapping in the motor- and somatosensory regions. The mean CBF for whole brain GM was 40.6±8.4 ml/100g/min at rest and 42.6±8.6 ml/100g/min during activation. Finally the reliability of pCASL against the reference standard of PC-MR was high (ICC = 0.80). The mean CBF for whole brain measured with PC-MRI was 54.3±10.1 ml/100g/min and 38.3±7.8 ml/100g/min with pCASL. Conclusions The results demonstrate moderate to high levels of repeatability and reliability for most brain regions, comparable to what has been reported for younger populations. The performance of pCASL at 1.5-Tesla shows that region-specific perfusion measurements with this technique are feasible in studies of a geriatric population. PMID:26659363

  14. Perfusion Electronic Record Documentation Using Epic Systems Software.

    PubMed

    Riley, Jeffrey B; Justison, George A

    2015-12-01

    The authors comment on Steffens and Gunser's article describing the University of Wisconsin adoption of the Epic anesthesia record to include perfusion information from the cardiopulmonary bypass patient experience. We highlight the current-day lessons and the valuable quality and safety principles the Wisconsin-Epic model anesthesia-perfusion record provides. PMID:26834289

  15. Brain abscess

    MedlinePlus

    Brain abscesses commonly occur when bacteria or fungi infect part of the brain. As a result, swelling and irritation (inflammation) develop. Infected brain cells, white blood cells, live and dead bacteria, ...

  16. Brain Tumors

    MedlinePlus

    ... brain. Brain tumors can be benign, with no cancer cells, or malignant, with cancer cells that grow quickly. Some are primary brain ... targeted therapy. Targeted therapy uses substances that attack cancer cells without harming normal cells. Many people get ...

  17. Brain components

    MedlinePlus Videos and Cool Tools

    The brain is composed of more than a thousand billion neurons. Specific groups of them, working in concert, provide ... of information. The 3 major components of the brain are the cerebrum, cerebellum, and brain stem. The ...

  18. Brain surgery

    MedlinePlus

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  19. Brain Malformations

    MedlinePlus

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  20. Sustained ventilation: perfusion imbalance during hemodialysis.

    PubMed

    Milner, L S; Rothberg, A D; Thomson, P D; Stothart, M

    1983-06-01

    Five children between the ages of 6 and 15 years, who required chronic hemodialysis (HD) for renal failure, were studied to evaluate the central and pulmonary effects of HD on gas exchange. Acetate dialysate was used, and dialysate pO2 and pCO2, arterial pO2 and pCO2, endtidal CO2 and minute ventilation were measured pre-HD and 15, 30, 60, 120 and 240 minutes after commencement of HD. Arterial-alveolar CO2 gradient (aADCO2) was calculated to determine the ventilation: perfusion (V/Q) status. Minute ventilation did not change significantly from the pre-HD value of 8.9 +/- 1.1 l/min (mean +/- SD). The aADCO2 increased significantly from 3.2 +/- 3.7 mmHg to 8.4 +/- 2.4 mmHg at 15 mins (p less than .01) and was still elevated at 120 mins. (9.1 +/- 3.4 mmHg, p less than .02). There was a weak but significant inverse relationship between aADCO2 and arterial pO2 (r -0.42, p less than 0.05). The results suggest that, in these children, dialysed at altitude, dialysis-related hypoxemia appears to be the result of a sustained V/Q mismatch, possibly related to a decrease in pulmonary perfusion. PMID:6413444

  1. Diagnosing acute lacunar infarction using CT perfusion.

    PubMed

    Cao, Wenjie; Yassi, Nawaf; Sharma, Gagan; Yan, Bernard; Desmond, Patricia M; Davis, Stephen M; Campbell, Bruce C V

    2016-07-01

    The value of CT perfusion (CTP) in detecting acute lacunar infarcts (LACI) has not been well established. We tested the sensitivity of CTP for LACI. CTP maps of consecutive stroke patients from 2009-2013 were examined. MRI diffusion imaging was used to identify those with LACI. Two stroke neurologists independently evaluated the CTP maps for evidence of a perfusion lesion in a deep perforating artery territory. Cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT) and time to maximum (Tmax) maps were first examined in isolation and then in combination. Inter-observer agreement was measured using Cohen's κ. The lesions identified were later confirmed against the diffusion MRI reference and the sensitivity and specificity of CTP maps calculated. A total of 63 patient scans were analysed. There were 32 patients with MRI-confirmed LACI within the coverage of CTP; 18 in the striatum, 10 thalamic, and four in the corona radiata. Another 31 patients had normal MRI. Inter-rater agreement was good (κ=0.83). Sensitivity (blinded consensus) was highest for MTT (56.2%) compared to Tmax (25%, p<0.001), CBV (9.3%, p=0.021) and CBF (43.7%, p<0.001). MTT maps enable detection of a significant proportion of LACI using CTP. PMID:26899357

  2. Hepatic perfusion abnormalities during CT angiography: Detection and interpretation

    SciTech Connect

    Freeny, P.C.; Marks, W.M.

    1986-06-01

    Twenty-seven perfusion abnormalities were detected in 17 of 50 patients who underwent computed tomographic angiography (CTA) of the liver. All but one of the perfusion abnormalities occurred in patients with primary or metastatic liver tumors. Perfusion abnormalities were lobar in nine cases, segmental in 11, and subsegmental in seven; 14 were hypoperfusion and 13 were hyperperfusion abnormalities. The causes for the abnormalities included nonperfusion of a replaced hepatic artery (n = 11), cirrhosis and nodular regeneration (n = 3), altered hepatic hemodynamics (e.g., siphoning, laminar flow) caused by tumor (n = 7), contrast media washout from a nonperfused vessel (n = 1), compression of adjacent hepatic parenchyma (n = 1), and unknown (n = 4). Differentiation of perfusion abnormalities from tumor usually can be made by comparing the morphology of the known tumor with the suspected perfusion abnormality, changes of each on delayed CTA scans, and review of initial angiograms and other imaging studies.

  3. [Ocular perfusion pressure and its relevance for glaucoma].

    PubMed

    Schmidl, D; Werkmeister, R; Garhöfer, G; Schmetterer, L

    2015-02-01

    Ocular perfusion pressure is defined as the difference between arterial and venous pressure in ocular vessels. In practice, mean arterial pressure is used to substitute for arterial pressure in ocular vessels while intraocular pressure gives an estimate for ocular venous pressure. This results in a value that is easy to calculate and which is of importance since several studies have shown that it is correlated to the prevalence, incidence and progression of primary open angle glaucoma. Today, ocular perfusion pressure is used to estimate individual risks. Since no target value for ocular perfusion pressure can be defined, direct therapeutic intervention is difficult. Still, it has to be kept in mind that lowering intraocular pressure automatically leads to an increase in ocular perfusion pressure. The present article also points out problems and limitations in the concept of ocular perfusion pressure and suggests possible solutions for these problems in the future. PMID:25700252

  4. Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis

    SciTech Connect

    Kahan, A.; Devaux, J.Y.; Amor, B.; Menkes, C.J.; Weber, S.; Nitenberg, A.; Venot, A.; Guerin, F.; Degeorges, M.; Roucayrol, J.C.

    1986-05-29

    Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined.

  5. Regional Myocardial Perfusion Rates in Patients with Coronary Artery Disease

    PubMed Central

    Cannon, Paul J.; Dell, Ralph B.; Dwyer, Edward M.

    1972-01-01

    Regional myocardial perfusion rates were estimated from the myocardial washout of 133Xenon in 24 patients with heart disease whose coronary arteriograms were abnormal and 17 similar subjects whose coronary arteriograms were judged to be normal. Disappearance rates of 133Xe from multiple areas of the heart were monitored externally with a multiple-crystal scintillation camera after the isotope had been injected into a coronary artery and local myocardial perfusion rates were calculated by the Kety formula. The mean myocardial perfusion rates in the left ventricle exceeded those in the right ventricle or atrial regions in subjects without demonstrable coronary artery disease. In this group there was a significant lack of homogeneity of local perfusion rates in left ventricular myocardium; the mean coefficient of variation of left ventricular local perfusion rates was 15.8%. In the patients with radiographically demonstrable coronary artery disease, a variety of myocardial perfusion patterns were observed. Local capillary blood flow rates were depressed throughout the myocardium of patients with diffuse coronary disease but were subnormal only in discrete myocardial regions of others with localized occlusive disease. Local myocardial perfusion rates were similar to those found in the group with normal coronary arteriograms in patients with slight degrees of coronary disease and in those areas of myocardium distal to marked coronary constrictions or occlusions which were well supplied by collateral vessels. In subjects with right coronary disease, the mean right ventricular perfusion rates were significantly subnormal; in seven subjects of this group perfusion of the inferior left ventricle by a dominant right coronary artery was absent or depressed. The average mean left ventricular perfusion rate of 12 subjects with significant disease of two or more branches of the left coronary artery was significantly lower than that of the group with normal left coronary

  6. Increased Resting-State Perfusion after Repeated Encoding Is Related to Later Retrieval of Declarative Associative Memories

    PubMed Central

    Groen, Georg; Sokolov, Alexander N.; Jonas, Christina; Roebling, Robert; Spitzer, Manfred

    2011-01-01

    Electrophysiological studies in animals have shown coordinated reactivation of neuronal ensembles during a restricted time period of behavioral inactivity that immediately followed active encoding. In the present study we directly investigated off-line processing of associative memory formation in the human brain. Subjects' regional cerebral blood flow (rCBF) as a surrogate marker of neural activity during rest was measured by MR-based perfusion imaging in a sample of 14 healthy male subjects prior to (Pre2) and after (Post) extensive learning of 24 face-name associations within a selective reminding task (SR). Results demonstrated significant Post-Pre2 rCBF increases in hippocampal and temporal lobe regions, while in a control comparison of two perfusion scans with no learning task in-between (Pre2-Pre1) no differences in rCBF emerged. Post perfusion scanning was followed by a surprise cued associative recall task from which two types of correctly retrieved names were obtained: older names already correctly retrieved at least once during one of the SR blocks, and recent names acquired during the last SR block immediately prior to the Post scan. In the anterior hippocampus individual perfusion increases were correlated with both correct retrievals of older and recent names. By contrast, older but not recently learned names showed a significant correlation with perfusion increases in the left lateral temporal cortex known to be associated with long-term memory. Recent, but not older names were correlated with dopaminergic midbrain structures reported to contribute to the persistence of memory traces for novel information. Although the direct investigation of off-line memory processing did not permit concomitant experimental control, neither intentional rehearsal, nor substantial variations in subjects' states of alertness appear to contribute to present results. We suggest that the observed rCBF increases might reflect processes that possibly contribute to the long

  7. Dynamic contrast-enhanced magnetic resonance imaging: fundamentals and application to the evaluation of the peripheral perfusion

    PubMed Central

    Gordon, Yaron; Partovi, Sasan; Müller-Eschner, Matthias; Amarteifio, Erick; Bäuerle, Tobias; Weber, Marc-André; Kauczor, Hans-Ulrich

    2014-01-01

    Introduction The ability to ascertain information pertaining to peripheral perfusion through the analysis of tissues’ temporal reaction to the inflow of contrast agent (CA) was first recognized in the early 1990’s. Similar to other functional magnetic resonance imaging (MRI) techniques such as arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) MRI, dynamic contrast-enhanced MRI (DCE-MRI) was at first restricted to studies of the brain. Over the last two decades the spectrum of ailments, which have been studied with DCE-MRI, has been extensively broadened and has come to include pathologies of the heart notably infarction, stroke and further cerebral afflictions, a wide range of neoplasms with an emphasis on antiangiogenic treatment and early detection, as well as investigations of the peripheral vascular and musculoskeletal systems. Applications to peripheral perfusion DCE-MRI possesses an unparalleled capacity to quantitatively measure not only perfusion but also other diverse microvascular parameters such as vessel permeability and fluid volume fractions. More over the method is capable of not only assessing blood flowing through an organ, but in contrast to other noninvasive methods, the actual tissue perfusion. These unique features have recently found growing application in the study of the peripheral vascular system and most notably in the diagnosis and treatment of peripheral arterial occlusive disease (PAOD). Review outline The first part of this review will elucidate the fundamentals of data acquisition and interpretation of DCE-MRI, two areas that often remain baffling to the clinical and investigating physician because of their complexity. The second part will discuss developments and exciting perspectives of DCE-MRI regarding the assessment of perfusion in the extremities. Emerging clinical applications of DCE-MRI will be reviewed with a special focus on investigation of physiology and pathophysiology of the microvascular and

  8. Measuring perfusion with light (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Jansen, Sanne M. A.; de Bruin, Daniel M.; Faber, Dirk J.; van Leeuwen, Ton G.

    2016-03-01

    There is no gold standard test for perfusion evaluation in surgery. Optical Imaging techniques are able to image tissue at high resolution and in real-time. Laser Speckle Contrast Imaging, Optical Coherence Tomography, Sidestream Darkfield and Incident Darkfield all use the interaction of light with tissue to create an image. To test their feasibility and explore validity in a controlled setting, we created a phantom with the optical properties of tissue and microvascular channels of 30-400 micrometer. With a Hamilton Syringe Pump we mimicked blood flow velocities of 0-20 mm/sec. Images of all different modalities at different blood flow velocities were compared in terms of imaging depth, resoluation and hemodynamic parameters.

  9. Adenosine thallium 201 myocardial perfusion scintigraphy

    SciTech Connect

    Verani, M.S. )

    1991-07-01

    Pharmacologic coronary vasodilation as an adjunct to myocardial perfusion imaging has become increasingly important in the evaluation of patients with coronary artery disease, in view of the large number of patients who cannot perform an adequate exercise test or in whom contraindications render exercise inappropriate. Adenosine is a very potent coronary vasodilator and when combined with thallium 201 scintigraphy produces images of high quality, with the added advantages of a very short half-life (less than 10 seconds) and the ability to adjust the dose during the infusion, which may enhance safety and curtail the duration of side effects. The reported sensitivity and specificity of adenosine thallium 201 scintigraphy for the detection of coronary artery disease are high and at least comparable with imaging after exercise or dipyridamole administration. 23 refs.

  10. Hydrogels for Engineering of Perfusable Vascular Networks

    PubMed Central

    Liu, Juan; Zheng, Huaiyuan; Poh, Patrina S. P.; Machens, Hans-Günther; Schilling, Arndt F.

    2015-01-01

    Hydrogels are commonly used biomaterials for tissue engineering. With their high-water content, good biocompatibility and biodegradability they resemble the natural extracellular environment and have been widely used as scaffolds for 3D cell culture and studies of cell biology. The possible size of such hydrogel constructs with embedded cells is limited by the cellular demand for oxygen and nutrients. For the fabrication of large and complex tissue constructs, vascular structures become necessary within the hydrogels to supply the encapsulated cells. In this review, we discuss the types of hydrogels that are currently used for the fabrication of constructs with embedded vascular networks, the key properties of hydrogels needed for this purpose and current techniques to engineer perfusable vascular structures into these hydrogels. We then discuss directions for future research aimed at engineering of vascularized tissue for implantation. PMID:26184185

  11. Ex vivo lung perfusion in Brazil

    PubMed Central

    Abdalla, Luis Gustavo; Braga, Karina Andrighetti de Oliveira; Nepomuceno, Natalia Aparecida; Fernandes, Lucas Matos; Samano, Marcos Naoyuki; Pêgo-Fernandes, Paulo Manuel

    2016-01-01

    Objective: To evaluate the use of ex vivo lung perfusion (EVLP) clinically to prepare donor lungs for transplantation. Methods: A prospective study involving EVLP for the reconditioning of extended-criteria donor lungs, the criteria for which include aspects such as a PaO2/FiO2 ratio < 300 mmHg. Between February of 2013 and February of 2014, the lungs of five donors were submitted to EVLP for up to 4 h each. During EVLP, respiratory mechanics were continuously evaluated. Once every hour during the procedure, samples of the perfusate were collected and the function of the lungs was evaluated. Results: The mean PaO2 of the recovered lungs was 262.9 ± 119.7 mmHg at baseline, compared with 357.0 ± 108.5 mmHg after 3 h of EVLP. The mean oxygenation capacity of the lungs improved slightly over the first 3 h of EVLP-246.1 ± 35.1, 257.9 ± 48.9, and 288.8 ± 120.5 mmHg after 1, 2, and 3 h, respectively-without significant differences among the time points (p = 0.508). The mean static compliance was 63.0 ± 18.7 mmHg, 75.6 ± 25.4 mmHg, and 70.4 ± 28.0 mmHg after 1, 2, and 3 h, respectively, with a significant improvement from hour 1 to hour 2 (p = 0.029) but not from hour 2 to hour 3 (p = 0.059). Pulmonary vascular resistance remained stable during EVLP, with no differences among time points (p = 0.284). Conclusions: Although the lungs evaluated remained under physiological conditions, the EVLP protocol did not effectively improve lung function, thus precluding transplantation. PMID:27167429

  12. Aβ degradation or cerebral perfusion? Divergent effects of multifunctional enzymes

    PubMed Central

    Miners, J. Scott; Palmer, Jennifer C.; Tayler, Hannah; Palmer, Laura E.; Ashby, Emma; Kehoe, Patrick G.; Love, Seth

    2014-01-01

    There is increasing evidence that deficient clearance of β-amyloid (Aβ) contributes to its accumulation in late-onset Alzheimer disease (AD). Several Aβ-degrading enzymes, including neprilysin (NEP), endothelin-converting enzyme (ECE), and angiotensin-converting enzyme (ACE) reduce Aβ levels and protect against cognitive impairment in mouse models of AD. In post-mortem human brain tissue we have found that the activity of these Aβ-degrading enzymes rise with age and increases still further in AD, perhaps as a physiological response that helps to minimize the build-up of Aβ. ECE-1/-2 and ACE are also rate-limiting enzymes in the production of endothelin-1 (ET-1) and angiotensin II (Ang II), two potent vasoconstrictors, increases in the levels of which are likely to contribute to reduced blood flow in AD. This review considers the possible interdependence between Aβ-degrading enzymes, ischemia and Aβ in AD: ischemia has been shown to increase Aβ production both in vitro and in vivo, whereas increased Aβ probably enhances ischemia by vasoconstriction, mediated at least in part by increased ECE and ACE activity. In contrast, NEP activity may help to maintain cerebral perfusion, by reducing the accumulation of Aβ in cerebral blood vessels and lessening its toxicity to vascular smooth muscle cells. In assessing the role of Aβ-degrading proteases in the pathogenesis of AD and, particularly, their potential as therapeutic agents, it is important to bear in mind the multifunctional nature of these enzymes and to consider their effects on other substrates and pathways. PMID:25309424

  13. The TRAP (twin reversed arterial perfusion) sequence - case presentation.

    PubMed

    Mărginean, Claudiu; Mărginean, Maria Oana; Mureşan, Daniel; Zahiu, LuminiŢa; Horváth, Emőke

    2016-01-01

    We present a particular case of TRAP (twin reversed arterial perfusion) syndrome, which has a very rarely association of the simultaneous existence of a rudimentary malformed heart and brain, and also other malformations like abdominal wall abnormality, absent bladder with present kidneys, and absence of the lungs, which appear only in a few cases on the receptor twin from this sequence, malformations incompatible with life. A Caucasian 26-year-old pregnant woman, at the first pregnancy, with a monochorionic-diamniotic pregnancy, 26 weeks of gestation was referred to our hospital, for polyhydramnios. The patient delivered a living female newborn, weighing 950 g, with an Apgar score of 2 at one minute - the donor fetus and a second female newborn with multiple malformations, no signs of life and who weighed 2300 g - the receptor fetus. The anatomopathological examination confirmed the TRAP sequence associated with severe facial dysmorphism, bilateral phocomelia and cardiac malformations (rudimentary hypoplastic, univentricular) and a vascular anastomosis between the two umbilical cords. Anemia and cardiac complications which can lead to cardiac failure, appear early during pregnancy and caused the death of the pumping twin. We emphasize that in our case of TRAP sequence, the ultrasound examination established the diagnosis of the syndrome with high accuracy. Therefore, we can conclude that the existence of a rudimentary heart and a vascular anastomosis between the two umbilical cords supports the apparition of TRAP sequence. The early diagnosis of this pathology, the observation of the pregnancy with the help of weekly ultrasounds and the intrauterine interventions can increase the survival chances of the donor fetus from the TRAP sequence. PMID:27151718

  14. CT Perfusion of the Liver: Principles and Applications in Oncology

    PubMed Central

    Kim, Se Hyung; Kamaya, Aya

    2014-01-01

    With the introduction of molecularly targeted chemotherapeutics, there is an increasing need for defining new response criteria for therapeutic success because use of morphologic imaging alone may not fully assess tumor response. Computed tomographic (CT) perfusion imaging of the liver provides functional information about the microcirculation of normal parenchyma and focal liver lesions and is a promising technique for assessing the efficacy of various anticancer treatments. CT perfusion also shows promising results for diagnosing primary or metastatic tumors, for predicting early response to anticancer treatments, and for monitoring tumor recurrence after therapy. Many of the limitations of early CT perfusion studies performed in the liver, such as limited coverage, motion artifacts, and high radiation dose of CT, are being addressed by recent technical advances. These include a wide area detector with or without volumetric spiral or shuttle modes, motion correction algorithms, and new CT reconstruction technologies such as iterative algorithms. Although several issues related to perfusion imaging—such as paucity of large multicenter trials, limited accessibility of perfusion software, and lack of standardization in methods—remain unsolved, CT perfusion has now reached technical maturity, allowing for its use in assessing tumor vascularity in larger-scale prospective clinical trials. In this review, basic principles, current acquisition protocols, and pharmacokinetic models used for CT perfusion imaging of the liver are described. Various oncologic applications of CT perfusion of the liver are discussed and current challenges, as well as possible solutions, for CT perfusion are presented. © RSNA, 2014 Online supplemental material is available for this article. PMID:25058132

  15. Contactless mapping of rhythmical phenomena in tissue perfusion using PPGI

    NASA Astrophysics Data System (ADS)

    Huelsbusch, Markus; Blazek, Vladimir

    2002-04-01

    This paper presents the experimental setup and preliminary results of a near infrared CCD camera based Photoplethysmography Imaging (PPGI) system, which has been shown to be suitable for contactless and spatially resolved assessment of rhythmical blood volume changes in the skin. To visualize the complex rhythmical patterns in the dermal perfusion the Wavelet Transform is utilized. It is able to jointly assess time and frequency behavior of signals and thus allows to analyze instationary oscillations and variabilities in the different human rhythmics. The presented system is expected to provide new insights into the functional sequences of physiological tissue perfusion as well as of the perfusion status in ulcer formation and wound healing.

  16. Perfusion CT imaging of treatment response in oncology.

    PubMed

    Prezzi, Davide; Khan, Aisha; Goh, Vicky

    2015-12-01

    Perfusion CT was first described in the 1970s but has become accepted as a clinical technique in recent years. In oncological practice Perfusion CT allows the downstream effects of therapies on the tumour vasculature to be monitored. From the dynamic changes in tumour and vascular enhancement following intravenous iodinated contrast agent administration, qualitative and quantitative parameters may be derived that reflect tumour perfusion, blood volume, and microcirculatory changes with treatment. This review outlines the mechanisms of action of available therapies and state-of-the-art imaging practice. PMID:25864440

  17. Deep Vein Thrombosis Presenting on Pulmonary Ventilation and Perfusion Scintigraphy.

    PubMed

    Itani, Malak; Fair, Joanna; Hillman, Zachary; Behnia, Fatemeh; Elojeimy, Saeed

    2016-10-01

    A 52-year-old woman presenting with dyspnea was referred for a ventilation and perfusion scan (VQ). VQ images (with Tc-DTPA [diethylene triamine pentaacetic acid aerosol] and Tc-MAA [macroaggregated albumin]) initially appeared normal; however, count rates on perfusion images were similar to ventilation images, implying little Tc-MAA had reached the lungs. Spot images of the injected extremity demonstrated focal Tc-MAA accumulation worrisome for a venous thrombus, subsequently confirmed by Doppler ultrasound. Careful attention to relative radiotracer count rates on VQ scans is crucial to ensure diagnostic utility. In addition, abnormal low perfusion radiotracer counts may unveil other pathology with important clinical implications. PMID:27556796

  18. Prognostic value of normal regadenoson stress perfusion cardiovascular magnetic resonance

    PubMed Central

    2013-01-01

    Background Regadenoson is a vasodilator stress agent that selectively activates the A2A receptor. Compared to adenosine, regadenoson is easier to administer and results in fewer side effects. Although extensively studied in patients undergoing nuclear perfusion imaging (MPI), its use for perfusion cardiovascular magnetic resonance (CMR) is not well described. The aim of this study was to determine the prognostic value of a normal regadenoson perfusion CMR in patients with known or suspected coronary artery disease. Methods Patients with known or suspected coronary artery disease were prospectively enrolled to receive perfusion CMR (Philips 1.5 T) with regadenoson. Three short-axis slices of the left ventricle (LV) were obtained during first pass of contrast using a hybrid GRE-EPI pulse sequence (0.075 mmol/kg Gadolinium-DTPA-BMA at 4 ml/sec). Imaging was performed 1 minute after injection of regadenoson (0.4 mg) and repeated 15 minutes after reversal of hyperemia with aminophylline (125 mg). Perfusion defects were documented if they persisted for ≥2 frames after peak enhancement of the LV cavity. CMR was considered abnormal if there was a resting wall motion abnormality, decreased LVEF (<40%), presence of LGE, or the presence of a perfusion defect during hyperemia. All patients were followed for a minimum of 1 year for major adverse cardiovascular event (MACE) defined as coronary revascularization, non-fatal myocardial infarction, and cardiovascular death. Results 149 patients were included in the final analysis. Perfusion defects were noted in 43/149 (29%) patients; 59/149 (40%) had any abnormality on CMR. During the mean follow-up period of 24 ± 9 months, 17/149 (11.4%) patients experienced MACE. The separation in the survival distributions for those with perfusion defects and those without perfusion defects was highly significant (log-rank p = 0.0001). When the absence of perfusion defects was added to the absence of other resting CMR

  19. Altered resting perfusion and functional connectivity of default mode network in youth with autism spectrum disorder

    PubMed Central

    Jann, Kay; Hernandez, Leanna M; Beck-Pancer, Devora; McCarron, Rosemary; Smith, Robert X; Dapretto, Mirella; Wang, Danny J J

    2015-01-01

    Background Neuroimaging studies can shed light on the neurobiological underpinnings of autism spectrum disorders (ASD). Studies of the resting brain have shown both altered baseline metabolism from PET/SPECT and altered functional connectivity (FC) of intrinsic brain networks based on resting-state fMRI. To date, however, no study has investigated these two physiological parameters of resting brain function jointly, or explored the relationship between these measures and ASD symptom severity. Methods Here, we used pseudo-continuous arterial spin labeling with 3D background-suppressed GRASE to assess resting cerebral blood flow (CBF) and FC in 17 youth with ASD and 22 matched typically developing (TD) children. Results A pattern of altered resting perfusion was found in ASD versus TD children including frontotemporal hyperperfusion and hypoperfusion in the dorsal anterior cingulate cortex. We found increased local FC in the anterior module of the default mode network (DMN) accompanied by decreased CBF in the same area. In our cohort, both alterations were associated with greater social impairments as assessed with the Social Responsiveness Scale (SRS-total T scores). While FC was correlated with CBF in TD children, this association between FC and baseline perfusion was disrupted in children with ASD. Furthermore, there was reduced long-range FC between anterior and posterior modules of the DMN in children with ASD. Conclusion Taken together, the findings of this study – the first to jointly assess resting CBF and FC in ASD – highlight new avenues for identifying novel imaging markers of ASD symptomatology. PMID:26445698

  20. Postmortem changes in the neuroanatomical characteristics of the primate brain: hippocampal formation.

    PubMed

    Lavenex, Pierre; Lavenex, Pamela Banta; Bennett, Jeffrey L; Amaral, David G

    2009-01-01

    Comparative studies of the structural organization of the brain are fundamental to our understanding of human brain function. However, whereas brains of experimental animals are fixed by perfusion of a fixative through the vasculature, human or ape brains are fixed by immersion after varying postmortem intervals. Although differential treatments might affect the fundamental characteristics of the tissue, this question has not been evaluated empirically in primate brains. Monkey brains were either perfused or acquired after varying postmortem intervals before immersion-fixation in 4% paraformaldehyde. We found that the fixation method affected the neuroanatomical characteristics of the monkey hippocampal formation. Soma size was smaller in Nissl-stained, immersion-fixed tissue, although overall brain volume was larger as compared to perfusion-fixed tissue. Nonphosphorylated high-molecular-weight neurofilament immunoreactivity was lower in CA3 pyramidal neurons, dentate mossy cells, and the entorhinal cortex, whereas it was higher in the mossy fiber pathway in immersion-fixed tissue. Serotonin-immunoreactive fibers were well stained in perfused tissue but were undetectable in immersion-fixed tissue. Although regional immunoreactivity patterns for calcium-binding proteins were not affected, intracellular staining degraded with increasing postmortem intervals. Somatostatin-immunoreactive clusters of large axonal varicosities, previously reported only in humans, were observed in immersion-fixed monkey tissue. In addition, calretinin-immunoreactive multipolar neurons, previously observed only in rodents, were found in the rostral dentate gyrus in both perfused and immersion-fixed brains. In conclusion, comparative studies of the brain must evaluate the effects of fixation on the staining pattern of each marker in every structure of interest before drawing conclusions about species differences. PMID:18972553

  1. EFFECT ON PERFUSION VALUES OF SAMPLING INTERVAL OF CT PERFUSION ACQUISITIONS IN NEUROENDOCRINE LIVER METASTASES AND NORMAL LIVER

    PubMed Central

    Ng, Chaan S.; Hobbs, Brian P.; Wei, Wei; Anderson, Ella F.; Herron, Delise H.; Yao, James C.; Chandler, Adam G.

    2014-01-01

    Objective To assess the effects of sampling interval (SI) of CT perfusion acquisitions on CT perfusion values in normal liver and liver metastases from neuroendocrine tumors. Methods CT perfusion in 16 patients with neuroendocrine liver metastases were analyzed by distributed parameter modeling to yield tissue blood flow, blood volume, mean transit time, permeability, and hepatic arterial fraction, for tumor and normal liver. CT perfusion values for the reference sampling interval of 0.5s (SI0.5) were compared with those of SI datasets of 1s, 2s, 3s and 4s, using mixed-effects model analyses. Results Increases in SI beyond 1s were associated with significant and increasing departures of CT perfusion parameters from reference values at SI0.5 (p≤0.0009). CT perfusion values deviated from reference with increasing uncertainty with increasing SIs. Findings for normal liver were concordant. Conclusion Increasing SIs beyond 1s yield significantly different CT perfusion parameter values compared to reference values at SI0.5. PMID:25626401

  2. Intracranial CT angiography obtained from a cerebral CT perfusion examination

    SciTech Connect

    Gratama van Andel, H. A. F.; Venema, H. W.; Majoie, C. B.; Den Heeten, G. J.; Grimbergen, C. A.; Streekstra, G. J.

    2009-04-15

    CT perfusion (CTP) examinations of the brain are performed increasingly for the evaluation of cerebral blood flow in patients with stroke and vasospasm after subarachnoid hemorrhage. Of the same patient often also a CT angiography (CTA) examination is performed. This study investigates the possibility to obtain CTA images from the CTP examination, thereby possibly obviating the CTA examination. This would save the patient exposure to radiation, contrast, and time. Each CTP frame is a CTA image with a varying amount of contrast enhancement and with high noise. To improve the contrast-to-noise ratio (CNR) we combined all 3D images into one 3D image after registration to correct for patient motion between time frames. Image combination consists of weighted averaging in which the weighting factor of each frame is proportional to the arterial contrast. It can be shown that the arterial CNR is maximized in this procedure. An additional advantage of the use of the time series of CTP images is that automatic differentiation between arteries and veins is possible. This feature was used to mask veins in the resulting 3D images to enhance visibility of arteries in maximum intensity projection (MIP) images. With a Philips Brilliance 64 CT scanner (64x0.625 mm) CTP examinations of eight patients were performed on 80 mm of brain using the toggling table technique. The CTP examination consisted of a time series of 15 3D images (2x64x0.625 mm; 80 kV; 150 mAs each) with an interval of 4 s. The authors measured the CNR in images obtained with weighted averaging, images obtained with plain averaging, and images with maximal arterial enhancement. The authors also compared CNR and quality of the images with that of regular CTA examinations and examined the effectiveness of automatic vein masking in MIP images. The CNR of the weighted averaged images is, on the average, 1.73 times the CNR of an image at maximal arterial enhancement in the CTP series, where the use of plain averaging

  3. In-vivo quantitative evaluation of perfusion zones and perfusion gradient in the deep inferior epigastric artery perforator flap

    NASA Astrophysics Data System (ADS)

    Saint-Cyr, Michel; Lakhiani, Chrisovalantis; Cheng, Angela; Mangum, Michael; Liang, Jinyang; Teotia, Sumeet; Livingston, Edward H.; Zuzak, Karel J.

    2013-03-01

    The selection of well-vascularized tissue during DIEP flap harvest remains controversial. While several studies have elucidated cross-midline perfusion, further characterization of perfusion to the ipsilateral hemiabdomen is necessary for minimizing rates of fat necrosis or partial fat necrosis in bilateral DIEP flaps. Eighteen patients (29 flaps) underwent DIEP flap harvest using a prospectively designed protocol. Perforators were marked and imaged with a novel system for quantitatively measuring tissue oxygenation, the Digital Light Hyperspectral Imager. Images were then analyzed to determine if perforator selection influenced ipsilateral flap perfusion. Flaps based on a single lateral row perforator (SLRP) were found to have a higher level of hemoglobin oxygenation in Zone I (mean %HbO2 = 76.1) compared to single medial row perforator (SMRP) flaps (%HbO2 = 71.6). Perfusion of Zone III relative to Zone I was similar between SLRP and SMRP flaps (97.4% vs. 97.9%, respectively). These differences were not statistically significant (p>0.05). Perfusion to the lateral edge of the flap was slightly greater for SLRP flaps compared SMRP flaps (92.1% vs. 89.5%, respectively). SMRP flaps had superior perfusion travelling inferiorly compared to SLRP flaps (88.8% vs. 83.9%, respectively). Overall, it was observed that flaps were better perfused in the lateral direction than inferiorly. Significant differences in perfusion gradients directed inferiorly or laterally were observed, and perforator selection influenced perfusion in the most distal or inferior aspects of the flap. This suggests broader clinical implications for flap design that merit further investigation.

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

    PubMed

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

    2016-01-01

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

  5. A Selective Insular Perfusion Deficit Contributes to Compromised Salience Network Connectivity in Recovering Alcoholic Men

    PubMed Central

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

    2013-01-01

    Background Alcoholism can disrupt neural synchrony between nodes of intrinsic functional networks that are maximally active when resting relative to engaging in a task, the default mode network (DMN) pattern. Untested, however, are whether the DMN in alcoholics can rebound normally from the relatively depressed task-state to the active resting-state and whether local perfusion deficits could disrupt network synchrony when switching from conditions of rest to task to rest, thereby indicating a physiological mechanism of neural network adaptation capability. Methods Whole-brain, 3D pulsed-continuous arterial spin labeling (PCASL) provided measurements of regional cerebral blood flow (rCBF) in 12 alcoholics and 12 controls under three conditions: pre-task rest, spatial working-memory task, post-task rest. Results With practice, alcoholics and controls achieved similar task accuracy and reaction times. Both groups exhibited a high-low-high pattern of perfusion levels in DMN regions during the rest-task-rest runs and the opposite pattern in posterior and cerebellar regions known to be associated with spatial working memory. Alcoholics showed selective differences from controls in the rest-task-rest CBF pattern in the anterior precuneus and CBF level in the insula, a hub of the salience network. Connectivity analysis identified activation synchrony from an insula seed to salience nodes (parietal, medial frontal, anterior cingulate cortices) in controls only. Conclusions We propose that attenuated insular CBF is a mechanism underlying compromised connectivity among salience network nodes. This local perfusion deficit in alcoholics has the potential to impair ability to switch from cognitive states of interoceptive cravings to cognitive control for curbing internal urges. PMID:23587427

  6. Spatial distribution of ventilation and perfusion: mechanisms and regulation.

    PubMed

    Glenny, Robb W; Robertson, H Thomas

    2011-01-01

    With increasing spatial resolution of regional ventilation and perfusion, it has become more apparent that ventilation and blood flow are quite heterogeneous in the lung. A number of mechanisms contribute to this regional variability, including hydrostatic gradients, pleural pressure gradients, lung compressibility, and the geometry of the airway and vascular trees. Despite this marked heterogeneity in both ventilation and perfusion, efficient gas exchange is possible through the close regional matching of the two. Passive mechanisms, such as the shared effect of gravity and the matched branching of vascular and airway trees, create efficient gas exchange through the strong correlation between ventilation and perfusion. Active mechanisms that match local ventilation and perfusion play little if no role in the normal healthy lung but are important under pathologic conditions. PMID:23737178

  7. Metabolism of 7-ethyoxycoumarin by Isolated Perfused Rainbow Trout Livers

    EPA Science Inventory

    Isolated trout livers were perfused using methods designed to preserve tissue viability and function. Liver performance was evaluated by measuring O2 consumption, vascular resistance, K+ leakage, glucose flux, lactate flux, alanine aminotransferase leakage, and metabolic clearanc...

  8. Pulmonary ventilation and perfusion studies in lung cancer

    SciTech Connect

    Narabayashi, I.; Otsuka, N.

    1984-02-01

    In 46 patients with bronchogenic carcinoma, the diagnostic significance of pulmonary ventilation images by the continuous inhalation of Kr-81m gas, which has an extremely short half life, was studied in comparison with pulmonary perfusion images with Tc-99m MAA. The data were processed using digital analysis techniques. There were 15 cases with discrepancies between ventilation and perfusion. The V/Q ratios of the affected lung among the 43 patients showed values above 1.2 in nine cases and below 0.8 in six cases. The Kr-81m ventilation and Tc-99m perfusion images were compared before and after radiation therapy in eight patients. It was possible to assess the therapeutic effect on regional ventilation and regional perfusion, which could not be evaluated by chest x-ray alone, under the same conditions of normal breathing.

  9. Arterial Perfusion Imaging–Defined Subvolume of Intrahepatic Cancer

    SciTech Connect

    Wang, Hesheng; Farjam, Reza; Feng, Mary; Hussain, Hero; Ten Haken, Randall K.; Lawrence, Theodore S.; Cao, Yue

    2014-05-01

    Purpose: To assess whether an increase in a subvolume of intrahepatic tumor with elevated arterial perfusion during radiation therapy (RT) predicts tumor progression after RT. Methods and Materials: Twenty patients with unresectable intrahepatic cancers undergoing RT were enrolled in a prospective, institutional review board–approved study. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed before RT (pre-RT), after delivering ∼60% of the planned dose (mid-RT) and 1 month after completion of RT to quantify hepatic arterial perfusion. The arterial perfusions of the tumors at pre-RT were clustered into low-normal and elevated perfusion by a fuzzy clustering-based method, and the tumor subvolumes with elevated arterial perfusion were extracted from the hepatic arterial perfusion images. The percentage changes in the tumor subvolumes and means of arterial perfusion over the tumors from pre-RT to mid-RT were evaluated for predicting tumor progression post-RT. Results: Of the 24 tumors, 6 tumors in 5 patients progressed 5 to 21 months after RT completion. Neither tumor volumes nor means of tumor arterial perfusion at pre-RT were predictive of treatment outcome. The mean arterial perfusion over the tumors increased significantly at mid-RT in progressive tumors compared with the responsive tumors (P=.006). From pre-RT to mid-RT, the responsive tumors had a decrease in the tumor subvolumes with elevated arterial perfusion (median, −14%; range, −75% to 65%), whereas the progressive tumors had an increase of the subvolumes (median, 57%; range, −7% to 165%) (P=.003). Receiver operating characteristic analysis of the percentage change in the subvolume for predicting tumor progression post-RT had an area under the curve of 0.90. Conclusion: The increase in the subvolume of the intrahepatic tumor with elevated arterial perfusion during RT has the potential to be a predictor for tumor progression post-RT. The tumor subvolume could be a radiation

  10. Arterial Perfusion Imaging-Defined Subvolume of Intrahepatic Cancer

    PubMed Central

    Wang, Hesheng; Farjam, Reza; Feng, Mary; Hussain, Hero; Ten Haken, Randall K.; Lawrence, Theodore S.; Cao, Yue

    2014-01-01

    Purpose To assess whether an increase in a subvolume of intrahepatic tumor with elevated arterial perfusion during radiation therapy (RT) predicts tumor progression post RT. Methods and Materials Twenty patients with unresectable intrahepatic cancers undergoing RT were enrolled in a prospective IRB-approved study. Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) were performed prior to RT (pre-RT), after delivering ~60% of the planned dose (mid-RT) and one month after completion of RT to quantify hepatic arterial perfusion. The arterial perfusions of the tumors at pre-RT were clustered into low-normal and elevated perfusion by a fuzzy clustering-based method, and the tumor subvolumes with elevated arterial perfusion were extracted from the hepatic arterial perfusion images. The percentage changes in the tumor subvolumes and means of arterial perfusion over the tumors from pre-RT to mid-RT were evaluated for predicting tumor progression post-RT. Results Of the 24 tumors, 6 tumors in 5 patients progressed 5–21 months after RT completion. Neither tumor volumes nor means of tumor arterial perfusion at pre-RT were predictive of treatment outcome. The mean arterial perfusion over the tumors increased significantly at mid-RT in progressive tumors comparing to the responsive ones (p=0.006). From pre-RT to mid-RT, the responsive tumors had a decrease in the tumor subvolumes with elevated arterial perfusion (median: −14%, range: −75% – 65%), while the progressing tumors had an increase of the subvolumes (median: 57%, range: −7% – 165%) (p=0.003). Receiver operating characteristic (ROC) analysis of the percentage change in the subvolume for predicting tumor progression post-RT had an area under the curve (AUC) of 0.90. Conclusion The increase in the subvolume of the intrahepatic tumor with elevated arterial perfusion during RT has the potential to be a predictor for tumor progression post-RT. The tumor subvolume could be a radiation boost candidate

  11. A perfusion chamber for physiological studies with acutely dissociated neurons.

    PubMed

    Wonderlin, W F; Weinreich, D

    1987-11-01

    We describe a recording chamber that immobilizes acutely dissociated neurons on an ultra-fine mesh grid positioned above a moving stream of perfusate. This chamber is easily fabricated and has two attributes for single-electrode voltage-clamp or patch-clamp recording: (1) shallow immersion (less than 20 micron) of the neurons, and (2) stable recording with rapid perfusion rates. PMID:3695568

  12. Perfusion of nonventilated lung: failure of hypoxic vasoconstriction

    SciTech Connect

    Sostman, H.D.; Neumann, R.D.; Gottschalk, A.; Greenspan, R.H.

    1983-07-01

    Alveolar hypoxia is a well established cause of regional vasoconstriction such that nonventilated segments are not perfused. The paradoxical situation of retained perfusion of nonventilated lung has seldom been discussed. Three clinical examples are illustrated. In each case coexistent chronic obstructive lung disease may have contributed to this unexpected finding by reducing pulmonary vascular capacity such that blood flow diversion from hypoxic segments was not possible.

  13. Evaluation of Microvascular Perfusion and Resuscitation after Severe Injury.

    PubMed

    Lee, Yann-Leei L; Simmons, Jon D; Gillespie, Mark N; Alvarez, Diego F; Gonzalez, Richard P; Brevard, Sidney B; Frotan, Mohammad A; Schneider, Andrew M; Richards, William O

    2015-12-01

    Achieving adequate perfusion is a key goal of treatment in severe trauma; however, tissue perfusion has classically been measured by indirect means. Direct visualization of capillary flow has been applied in sepsis, but application of this technology to the trauma population has been limited. The purpose of this investigation was to compare the efficacy of standard indirect measures of perfusion to direct imaging of the sublingual microcirculatory flow during trauma resuscitation. Patients with injury severity scores >15 were serially examined using a handheld sidestream dark-field video microscope. In addition, measurements were also made from healthy volunteers. The De Backer score, a morphometric capillary density score, and total vessel density (TVD) as cumulative vessel area within the image, were calculated using Automated Vascular Analysis (AVA3.0) software. These indices were compared against clinical and laboratory parameters of organ function and systemic metabolic status as well as mortality. Twenty severely injured patients had lower TVD (X = 14.6 ± 0.22 vs 17.66 ± 0.51) and De Backer scores (X = 9.62 ± 0.16 vs 11.55 ± 0.37) compared with healthy controls. These scores best correlated with serum lactate (TVD R(2) = 0.525, De Backer R(2) = 0.576, P < 0.05). Mean arterial pressure, heart rate, oxygen saturation, pH, bicarbonate, base deficit, hematocrit, and coagulation parameters correlated poorly with both TVD and De Backer score. Direct measurement of sublingual microvascular perfusion is technically feasible in trauma patients, and seems to provide real-time assessment of microcirculatory perfusion. This study suggests that in severe trauma, many indirect measurements of perfusion do not correlate with microvascular perfusion. However, visualized perfusion deficiencies do reflect a shift toward anaerobic metabolism. PMID:26736167

  14. Simulation in perfusion: where do we go from here?

    PubMed

    Fernandez, Adam

    2010-01-01

    Simulation is a common training modality used in aviation, the nuclear industry and by many medical specialties. The adoption of simulation by introductory perfusion education for beginning students and continuing medical education by cardiovascular perfusion has not kept pace with other fields and this paper explores issues connected with simulation in other professions, including training as it currently exists, access to simulator technology, and what could be achieved by utilizing simulator technology. PMID:20159937

  15. Diurnal Curve of the Ocular Perfusion Pressure

    PubMed Central

    Moreira, TCA; Bezerra, BSP; Vianello, MP; Corradi, J; Dorairaj, SK; Prata, TS

    2016-01-01

    ABSTRACT Purpose: To describe the diurnal variation of the ocular perfusion pressure (OPP) in normal, suspects and glaucoma patients. Materials and methods: Seventy-nine subjects were enrolled in a prospective study. The diurnal curve of intraocular pressure (IOP) was performed and blood pressure measurements were obtained. Each participant was grouped into one of the following based upon the clinical evaluation of the optic disk, IOP and standard achromatic perimetry (SAP): 18 eyes were classified as normal (normal SAP, normal optic disk evaluation and IOP < 21 mm Hg in two different measurements), 30 eyes as glaucoma suspect (GS) (normal SAP and mean deviation (MD), C/D ration > 0.5 or asymmetry > 0.2 and/or ocular hypertension), 31 eyes as early glaucoma (MD < -6 dB, glaucomatous optic neuropathy and SAP and MDs on SAP. Standard achromatic perimetry was performed with the Octopus 3.1.1 Dynamic 24-2 program. Intraocular pressure and blood pressure measurements were taken at 6 am, 9 am, 12, 3 and 6 pm. The patients stayed in the seated position for 5 minutes prior to blood pressure measurements. Results: The mean IOP values in all groups did not follow any regular pattern. The peak IOP was found to be greater in suspect [18.70 ± 3.31 (mm Hg ± SD)] and glaucoma (18.77 ± 4.30 mm Hg) patients as compared to normal subjects (16.11 ± 2.27 mm Hg). In studying the diurnal variation of the OPP, we found lower values at 3 pm in normals (34.21 ± 2.07 mm Hg), at 9 am in suspects (54.35 ± 3.32 mm Hg) and at 12 pm in glaucoma patients (34.84 ± 1.44 mm Hg). Conclusion: Each group has a specific OPP variation during the day with the most homogeneous group being the suspect one. It is important to keep studying the IOP and OPP variation for increased comprehension of the pathophysiology of glaucomatous optic neuropathy. How to cite this article: Kanadani FN, Moreira TCA, Bezerra BSP, Vianello MP, Corradi J, Dorairaj SK, Prata TS. Diurnal Curve of the Ocular Perfusion

  16. Transepithelial transport of glutathione in isolated perfused small intestine

    SciTech Connect

    Hagen, T.M.; Jones, D.P.

    1986-03-01

    Uptake of GSH was studied in isolated perfused segment of jejunum in the adult rat. Krebs-Henseleit buffer was infused through the superior mesenteric artery and fractions were collected from the portal vein. The maintenance of vascular and epithelial integrity was established by lack of transfer of /sup 14/C-inulin or /sup 14/C-polyethylene glycol from the lumen to the perfusate. (glycine-2-/sup 3/H)GSH was introduced in the lumen and perfusate fractions collected every min. With 1 mM GSH and 10 mM Gly in the lumen, transport into the perfusate was 220 nmol/min. Analysis by HPLC showed that 80% was at the intact tripeptide, GSH. No cysteinylgylcine was detected in the perfusate. Pretreatment of the segment with 0.25 mM acivicin and 1 mM buthionine sulfoximine had no significant effect on GSH transport rate, thus showing that degradation and resynthesis of GSH did not contribute to the appearance of GSH in the perfusate. GSH transport was inhibited 50% by replacing lumenal NaCl with choline Cl. Addition of 10 mM ..gamma..-Clu-Glu or 10 mM ophthalmic acid decreased the rat of transport by 60-70%. These results establish that transepithelial transport of intact GSH occurs in rat small intestine. This may allow utilization of dietary GSH or reutilization of biliary GSH. In addition, the results suggest that oral GSH may be of therapeutic benefit.

  17. A pump-free membrane-controlled perfusion microfluidic platform.

    PubMed

    Goral, Vasiliy N; Tran, Elizabeth; Yuen, Po Ki

    2015-09-01

    In this article, we present a microfluidic platform for passive fluid pumping for pump-free perfusion cell culture, cell-based assay, and chemical applications. By adapting the passive membrane-controlled pumping principle from the previously developed perfusion microplate, which utilizes a combination of hydrostatic pressure generated by different liquid levels in the wells and fluid wicking through narrow strips of a porous membrane connecting the wells to generate fluid flow, a series of pump-free membrane-controlled perfusion microfluidic devices was developed and their use for pump-free perfusion cell culture and cell-based assays was demonstrated. Each pump-free membrane-controlled perfusion microfluidic device comprises at least three basic components: an open well for generating fluid flow, a micron-sized deep chamber/channel for cell culture or for fluid connection, and a wettable porous membrane for controlling the fluid flow. Each component is fluidically connected either by the porous membrane or by the micron-sized deep chamber/channel. By adapting and incorporating the passive membrane-controlled pumping principle into microfluidic devices, all the benefits of microfluidic technologies, such as small sample volumes, fast and efficient fluid exchanges, and fluid properties at the micro-scale, can be fully taken advantage of with this pump-free membrane-controlled perfusion microfluidic platform. PMID:26392835

  18. Correlations of leuko-araiosis with cerebral atrophy and perfusion in elderly normal subjects and demented patients.

    PubMed Central

    Kawamura, J; Meyer, J S; Ichijo, M; Kobari, M; Terayama, Y; Weathers, S

    1993-01-01

    CT images of leuko-araiosis in brain slices were quantified according to volumes of reduced Hounsfield units in frontal periventricular white matter in groups of elderly patients with multi-infarct dementia (MID, n = 23) and dementia of the Alzheimer type (DAT, n = 16). Volumes of leuko-araiosis, estimates of atrophic cerebral tissue, and local cerebral perfusion utilising inhalation of xenon gas as the indicator were correlated on the same CT slices. Ratios of frontal leuko-araiosis to total brain tissue volume were similar for patients with MID and DAT (mean 5.7 (SD 2.1)% v 6.5 (3.2%)), and both were significantly greater than ratios in elderly normal volunteers (3.1(1.3)%, 0 < 0.001). Cerebral atrophy (measured as the ratio of volumes of cerebrospinal fluid to total brain area) for DAT patients was 17.0 (6.7)%, which was greater than for MID patients (12.5 (5.4)%; p < 0.05) and both types of patients showed more cerebral atrophy than did age matched, elderly normal subjects. Cerebral perfusion was decreased in all regions measured in patients with MID and DAT compared with elderly normal subjects. Multi variate regression analyses correlated frontal leuko-araiosis with reductions of local cerebral blood flow in subcortical grey matter (p < 0.025) in patients with vascular dementia but not in those with DAT. These quantitative measures implicate decreased perfusion due to atherosclerosis in territories supplied by the deep penetrating cerebral arteries in the pathogenesis of leuko-araiosis in patients with vascular dementia, but suggest a different pathogenesis for leuko-araiosis in Alzheimer's disease. Images PMID:8437007

  19. Comparison of dynamic susceptibility contrast-MRI perfusion quantification methods in the presence of delay and dispersion

    NASA Astrophysics Data System (ADS)

    Maan, Bianca; Simões, Rita Lopes; Meijer, Frederick J. A.; Klaas Jan Renema, W.; Slump, Cornelis H.

    2011-03-01

    The perfusion of the brain is essential to maintain brain function. Stroke is an example of a decrease in blood flow and reduced perfusion. During ischemic stroke the blood flow to tissue is hampered due to a clot inside a vessel. To investigate the recovery of stroke patients, follow up studies are necessary. MRI is the preferred imaging modality for follow up because of the absence of radiation dose concerns, contrary to CT. Dynamic Susceptibility Contrast (DSC) MRI is an imaging technique used for measuring perfusion of the brain, however, is not standard applied in the clinical routine due to lack of immediate patient benefit. Several post processing algorithms are described in the literature to obtain cerebral blood flow (CBF). The quantification of CBF relies on the deconvolution of a tracer concentration-time curve in an arterial and a tissue voxel. There are several methods to obtain this deconvolution based on singular-value decomposition (SVD). This contribution describes a comparison between the different approaches as currently there is no best practice for (all) clinical relevant situations. We investigate the influence of tracer delay, dispersion and recirculation on the performance of the methods. In the presence of negative delays, the truncated SVD approach overestimates the CBF. Block-circulant and reformulated SVD are delay-independent. Due to its delay dependent behavior, the truncated SVD approach performs worse in the presence of dispersion as well. However all SVD approaches are dependent on the amount of dispersion. Moreover, we observe that the optimal truncation parameter varies when recirculation is added to noisy data, suggesting that, in practice, these methods are not immune to tracer recirculation. Finally, applying the methods to clinical data resulted in a large variability of the CBF estimates. Block-circulant SVD will work in all situations and is the method with the highest potential.

  20. Oncolytic vesicular stomatitis virus administered by isolated limb perfusion suppresses osteosarcoma growth.

    PubMed

    Kubo, Tadahiko; Shimose, Shoji; Matsuo, Toshihiro; Fujimori, Jun; Sakaguchi, Takemasa; Yamaki, Minoru; Shinozaki, Katsunori; Woo, Savio L C; Ochi, Mitsuo

    2011-05-01

    A significant limitation to oncolytic virotherapy in vivo is the lack of a clinically relevant means of delivering the virus. We evaluated the oncolytic activity of vesicular stomatitis virus (VSV) in human osteosarcoma cells and explored isolated limb perfusion (ILP) as a novel oncolytic virus delivery system to extremity sarcoma in immune-competent rats. Human and rat osteosarcoma cells transduced with rVSV-lacZ uniformly expressed β-gal. VSV was fully capable of replicating its RNA genome in all osteosarcoma cell lines, and efficiently killed them in time- and dose-dependent manners, whereas normal bone marrow stromal cells were refractory to the virus. VSV delivered by ILP inhibited growth of osteosarcoma xenografts more potently than that injected intravenously and intratumorally in the hind limb of immune-competent rats. Histopathological sections of tumor lesions treated by ILP-delivered VSV showed positive for VSV-G protein. There were no VSV-G expressions in perfused leg muscle, nonperfused leg muscle, brain, lung, and liver in VSV-treated rats. Our findings show efficient VSV gene expression and replication in osteosarcoma cells, suggesting that osteosarcoma may be a promising target for oncolytic virotherapy with VSV. Furthermore, we firstly showed that ILP of VSV against extremity sarcoma caused antitumor activity. PMID:21437961

  1. Isolated limb perfusion with fotemustine after chemosensitization with dacarbazine in melanoma.

    PubMed

    Pontes, L; Lopes, M; Ribeiro, M; Santos, J G; Azevedo, M C

    1997-10-01

    Isolated limb perfusion (ILP) has been reported as the most effective treatment for localized recurrent melanoma of the limbs. In terms of local and regional control with melphalan, complete remission is achieved in about 40% of patients, with frequent toxicity causing significant short-term disability in many and long-term incapacity in a few. Since 1989, several studies have reported success using a combination of fotemustine and dacarbazine (DTIC) in the systemic treatment of disseminated melanoma and brain metastasis. In May 1995, we began a pilot study with systemic DTIC 400 mg/m2 given intravenously about 4 h before ILP using fotemustine in an intra-arterial bolus of 100-150 mg/m2 as the perfusion agent. By July 1996, 10 patients had been included in the study. The results were evaluated in terms of the response rate (five complete responses and one partial response in the six patients who could be evaluated), local toxicity (nine patients with level I and one with level II, measured on the Wieberdink scale) and systemic toxicity (nine patients with level 0 and one with level 1, measured on the World Health Organization scale). Treatment was effective, with a similar response rate to that obtained with melphalan but with much lower toxicity, so this protocol may represent an innovation in loco-regional therapy and should be further investigated in a large trial. PMID:9429225

  2. 3D GRASE PROPELLER: Improved Image Acquisition Technique for Arterial Spin Labeling Perfusion Imaging

    PubMed Central

    Tan, Huan; Hoge, W. Scott; Hamilton, Craig A.; Günther, Matthias; Kraft, Robert A.

    2014-01-01

    Arterial spin labeling (ASL) is a non-invasive technique that can quantitatively measure cerebral blood flow (CBF). While traditionally ASL employs 2D EPI or spiral acquisition trajectories, single-shot 3D GRASE is gaining popularity in ASL due to inherent SNR advantage and spatial coverage. However, a major limitation of 3D GRASE is through-plane blurring caused by T2 decay. A novel technique combining 3D GRASE and a PROPELLER trajectory (3DGP) is presented to minimize through-plane blurring without sacrificing perfusion sensitivity or increasing total scan time. Full brain perfusion images were acquired at a 3×3×5mm3 nominal voxel size with Q2TIPS-FAIR as the ASL preparation sequence. Data from 5 healthy subjects was acquired on a GE 1.5T scanner in less than 4 minutes per subject. While showing good agreement in CBF quantification with 3D GRASE, 3DGP demonstrated reduced through-plane blurring, improved anatomical details, high repeatability and robustness against motion, making it suitable for routine clinical use. PMID:21254211

  3. Brain abscess

    MedlinePlus

    ... with certain heart disorders, may receive antibiotics before dental or other procedures to help reduce the risk of infection. Alternative Names Abscess - brain; Cerebral abscess; CNS abscess Images Amebic brain ...

  4. Brain Diseases

    MedlinePlus

    The brain is the control center of the body. It controls thoughts, memory, speech, and movement. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, ...

  5. Brain surgery

    MedlinePlus

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... Before surgery, the hair on part of the scalp is shaved and the area is cleaned. The doctor makes ...

  6. Brain Health

    MedlinePlus

    ... exercise, diet and nutrition, cognitive activity, and social engagement — can help keep your body and brain ... Stay Mentally Active > Mentally challenging activities and social engagement may support brain health. Learn More Plan ahead ...

  7. Integrating evidence-based perfusion into practices: the International Consortium for Evidence-Based Perfusion.

    PubMed

    Likosky, Donald S

    2006-12-01

    There is surmounting pressure for clinicians domestically and abroad not only to practice evidence-based perfusion, but also to supplement practice with documentation thereof. In this editorial, I shall describe an international initiative aimed at embracing this dictum from patients, regulatory bodies, and payers. "Research is the only hope that the future will be different than the past"- Daniel Mintz, MD "Practical men who believe themselves to be quite exempt from any intellectual influences are usually the slaves of some defunct economist.... It is ideas not vested interests which are dangerous for good or evil."-John Maynard Keynes. PMID:17312899

  8. Integrating Evidence-Based Perfusion Into Practices: The International Consortium for Evidence-Based Perfusion

    PubMed Central

    Likosky, Donald S.

    2006-01-01

    Abstract: There is surmounting pressure for clinicians domestically and abroad not only to practice evidence-based perfusion, but also to supplement practice with documentation thereof. In this editorial, I shall describe an international initiative aimed at embracing this dictum from patients, regulatory bodies, and payers. “Research is the only hope that the future will be different than the past”—Daniel Mintz, MD “Practical men who believe themselves to be quite exempt from any intellectual influences are usually the slaves of some defunct economist…. It is ideas not vested interests which are dangerous for good or evil.”—John Maynard Keynes PMID:17312899

  9. Perfusion Angiography in Acute Ischemic Stroke.

    PubMed

    Scalzo, Fabien; Liebeskind, David S

    2016-01-01

    Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and T max, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. PMID:27446232

  10. Myocardial perfusion echocardiography and coronary microvascular dysfunction

    PubMed Central

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-01-01

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  11. Myocardial perfusion echocardiography and coronary microvascular dysfunction.

    PubMed

    Barletta, Giuseppe; Del Bene, Maria Riccarda

    2015-12-26

    Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking. PMID:26730291

  12. Perfusion Angiography in Acute Ischemic Stroke

    PubMed Central

    Liebeskind, David S.

    2016-01-01

    Visualization and quantification of blood flow are essential for the diagnosis and treatment evaluation of cerebrovascular diseases. For rapid imaging of the cerebrovasculature, digital subtraction angiography (DSA) remains the gold standard as it offers high spatial resolution. This paper lays out a methodological framework, named perfusion angiography, for the quantitative analysis and visualization of blood flow parameters from DSA images. The parameters, including cerebral blood flow (CBF) and cerebral blood volume (CBV), mean transit time (MTT), time-to-peak (TTP), and Tmax, are computed using a bolus tracking method based on the deconvolution of the time-density curve on a pixel-by-pixel basis. The method is tested on 66 acute ischemic stroke patients treated with thrombectomy and/or tissue plasminogen activator (tPA) and also evaluated on an estimation task with known ground truth. This novel imaging tool provides unique insights into flow mechanisms that cannot be observed directly in DSA sequences and might be used to evaluate the impact of endovascular interventions more precisely. PMID:27446232

  13. New Trends in Radionuclide Myocardial Perfusion Imaging

    PubMed Central

    Hung, Guang-Uei; Wang, Yuh-Feng; Su, Hung-Yi; Hsieh, Te-Chun; Ko, Chi-Lun; Yen, Ruoh-Fang

    2016-01-01

    Radionuclide myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) has been widely used clinically as one of the major functional imaging modalities for patients with coronary artery disease (CAD) for decades. Ample evidence has supported the use of MPI as a useful and important tool in the diagnosis, risk stratification and treatment planning for CAD. Although popular in the United States, MPI has become the most frequently used imaging modality among all nuclear medicine tests in Taiwan. However, it should be acknowledged that MPI SPECT does have its limitations. These include false-positive results due to certain artifacts, false-negative due to balanced ischemia, complexity and adverse reaction arising from current pharmacological stressors, time consuming nature of the imaging procedure, no blood flow quantitation and relatively high radiation exposure. The purpose of this article was to review the recent trends in nuclear cardiology, including the utilization of positron emission tomography (PET) for MPI, new stressor, new SPECT camera with higher resolution and higher sensitivity, dynamic SPECT protocol for blood flow quantitation, new software of phase analysis for evaluation of LV dyssynchrony, and measures utilized for reducing radiation exposure of MPI. PMID:27122946

  14. In Vitro Perfused Human Capillary Networks

    PubMed Central

    Moya, Monica L.; Hsu, Yu-Hsiang; Lee, Abraham P.; Hughes, Christopher C.W.

    2013-01-01

    Replicating in vitro the complex in vivo tissue microenvironment has the potential to transform our approach to medicine and also our understanding of biology. In order to accurately model the 3D arrangement and interaction of cells and extracellular matrix, new microphysiological systems must include a vascular supply. The vasculature not only provides the necessary convective transport of oxygen, nutrients, and waste in 3D culture, but also couples and integrates the responses of organ systems. Here we combine tissue engineering and microfluidic technology to create an in vitro 3D metabolically active stroma (∼1 mm3) that, for the first time, contains a perfused, living, dynamic, interconnected human capillary network. The range of flow rate (μm/s) and shear rate (s−1) within the network was 0–4000 and 0–1000, respectively, and thus included the normal physiological range. Infusion of FITC dextran demonstrated microvessels (15–50 μm) to be largely impermeable to 70 kDa. Our high-throughput biology-directed platform has the potential to impact a broad range of fields that intersect with the microcirculation, including tumor metastasis, drug discovery, vascular disease, and environmental chemical toxicity. PMID:23320912

  15. The Brain.

    ERIC Educational Resources Information Center

    Hubel, David H.

    1979-01-01

    This article on the brain is part of an entire issue about neurobiology and the question of how the human brain works. The brain as an intricate tissue composed of cells is discussed based on the current knowledge and understanding of its composition and structure. (SA)

  16. Brain Aneurysm

    MedlinePlus

    A brain aneurysm is an abnormal bulge or "ballooning" in the wall of an artery in the brain. They are sometimes called berry aneurysms because they ... often the size of a small berry. Most brain aneurysms produce no symptoms until they become large, ...

  17. Color-Doppler sonographic tissue perfusion measurements reveal significantly diminished renal cortical perfusion in kidneys with vesicoureteral reflux

    PubMed Central

    Scholbach, T. M.; Sachse, C.

    2016-01-01

    Vesicoureteral reflux (VUR) and its sequelae may lead to reduced renal perfusion and loss of renal function. Methods to describe and monitor tissue perfusion are needed. We investigated dynamic tissue perfusion measurement (DTPM) with the PixelFlux-software to measure microvascular changes in the renal cortex in 35 children with VUR and 28 healthy children. DTPM of defined horizontal slices of the renal cortex was carried out. A kidney was assigned to the “low grade reflux”-group if the reflux grade of the voiding cystourethrogram was 1 to 3 and to the “high grade reflux”-group if the reflux grade was 4 to 5. Kidneys with VUR showed a significantly reduced cortical perfusion. Compared to healthy kidneys, this decline reached in low and high grade refluxes within the proximal 50% of the cortex: 3% and 12 %, in the distal 50% of the cortex: 21% and 44 % and in the most distal 20 % of the cortex 41% and 44%. DTPM reveals a perfusion loss in kidneys depending on the degree of VUR, which is most pronounced in the peripheral cortex. Thus, DTPM offers the tool to evaluate microvascular perfusion, to help planning treatment decisions in children with VUR. PMID:27051133

  18. Left Brain. Right Brain. Whole Brain

    ERIC Educational Resources Information Center

    Farmer, Lesley S. J.

    2004-01-01

    As the United States student population is becoming more diverse, library media specialists need to find ways to address these distinctive needs. However, some of these differences transcend culture, touching on variations in the brain itself. Most people have a dominant side of the brain, which can affect their personality and learning style.…

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

    PubMed

    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

  20. Denoising and artefact reduction in dynamic flat detector CT perfusion imaging using high speed acquisition: first experimental and clinical results.

    PubMed

    Manhart, Michael T; Aichert, André; Struffert, Tobias; Deuerling-Zheng, Yu; Kowarschik, Markus; Maier, Andreas K; Hornegger, Joachim; Doerfler, Arnd

    2014-08-21

    Flat detector CT perfusion (FD-CTP) is a novel technique using C-arm angiography systems for interventional dynamic tissue perfusion measurement with high potential benefits for catheter-guided treatment of stroke. However, FD-CTP is challenging since C-arms rotate slower than conventional CT systems. Furthermore, noise and artefacts affect the measurement of contrast agent flow in tissue. Recent robotic C-arms are able to use high speed protocols (HSP), which allow sampling of the contrast agent flow with improved temporal resolution. However, low angular sampling of projection images leads to streak artefacts, which are translated to the perfusion maps. We recently introduced the FDK-JBF denoising technique based on Feldkamp (FDK) reconstruction followed by joint bilateral filtering (JBF). As this edge-preserving noise reduction preserves streak artefacts, an empirical streak reduction (SR) technique is presented in this work. The SR method exploits spatial and temporal information in the form of total variation and time-curve analysis to detect and remove streaks. The novel approach is evaluated in a numerical brain phantom and a patient study. An improved noise and artefact reduction compared to existing post-processing methods and faster computation speed compared to an algebraic reconstruction method are achieved. PMID:25069101

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Denoising and artefact reduction in dynamic flat detector CT perfusion imaging using high speed acquisition: first experimental and clinical results

    NASA Astrophysics Data System (ADS)

    Manhart, Michael T.; Aichert, André; Struffert, Tobias; Deuerling-Zheng, Yu; Kowarschik, Markus; Maier, Andreas K.; Hornegger, Joachim; Doerfler, Arnd

    2014-08-01

    Flat detector CT perfusion (FD-CTP) is a novel technique using C-arm angiography systems for interventional dynamic tissue perfusion measurement with high potential benefits for catheter-guided treatment of stroke. However, FD-CTP is challenging since C-arms rotate slower than conventional CT systems. Furthermore, noise and artefacts affect the measurement of contrast agent flow in tissue. Recent robotic C-arms are able to use high speed protocols (HSP), which allow sampling of the contrast agent flow with improved temporal resolution. However, low angular sampling of projection images leads to streak artefacts, which are translated to the perfusion maps. We recently introduced the FDK-JBF denoising technique based on Feldkamp (FDK) reconstruction followed by joint bilateral filtering (JBF). As this edge-preserving noise reduction preserves streak artefacts, an empirical streak reduction (SR) technique is presented in this work. The SR method exploits spatial and temporal information in the form of total variation and time-curve analysis to detect and remove streaks. The novel approach is evaluated in a numerical brain phantom and a patient study. An improved noise and artefact reduction compared to existing post-processing methods and faster computation speed compared to an algebraic reconstruction method are achieved.

  3. Incidentally detected diaphragmatic hernia mimicking angina pectoris with Tc-99m MIBI myocardial perfusion imaging

    PubMed Central

    Cınar, Alev; Sadıc, Murat; Demırel, Koray; Korkmaz, Meliha

    2013-01-01

    In recent years 99mTechnetium methoxy-isobutyl-isonitrile (99mTc MIBI) is widely used in the evaluation of myocardial perfusion imaging (MPI). In this imaging protocol besides the cardiac evaluation, numerous other organs are included in the field of view. 99mTechnetium MIBI is taken up in all metabolically active tissue in the body except for the brain. Extracardiac uptake patterns as benign or serious conditions can be revealed during the MPI. In the imaging protocol, we should be aware of distribution of this radiotracer in order to recognize the abnormal uptake. Here in, we present a large diaphragmatic hernia, seemed as a mirror vision of myocardium that was determined incidentally during the MPI with 99mTc MIBI. PMID:24379540

  4. Brain Basics: Know Your Brain

    MedlinePlus

    ... fact sheet is a basic introduction to the human brain. It may help you understand how the healthy ... largest and most highly developed part of the human brain: it consists primarily of the cerebrum ( 2 ) and ...

  5. Schizophrenia patients differentiation based on MR vascular perfusion and volumetric imaging

    NASA Astrophysics Data System (ADS)

    Spanier, A. B.; Joskowicz, L.; Moshel, S.; Israeli, D.

    2015-03-01

    Candecomp/Parafac Decomposition (CPD) has emerged as a framework for modeling N-way arrays (higher-order matrices). CPD is naturally well suited for the analysis of data sets comprised of observations of a function of multiple discrete indices. In this study we evaluate the prospects of using CPD for modeling MRI brain properties (i.e. brain volume and gray-level) for schizophrenia diagnosis. Taking into account that 3D imaging data consists of millions of pixels per patient, the diagnosis of a schizophrenia patient based on pixel analysis constitutes a methodological challenge (e.g. multiple comparison problem). We show that the CPD could potentially be used as a dimensionality redaction method and as a discriminator between schizophrenia patients and match control, using the gradient of pre- and post Gd-T1-weighted MRI data, which is strongly correlated with cerebral blood perfusion. Our approach was tested on 68 MRI scans: 40 first-episode schizophrenia patients and 28 matched controls. The CPD subject's scores exhibit statistically significant result (P < 0.001). In the context of diagnosing schizophrenia with MRI, the results suggest that the CPD could potentially be used to discriminate between schizophrenia patients and matched control. In addition, the CPD model suggests for brain regions that might exhibit abnormalities in schizophrenia patients for future research.

  6. Hyperpolarized xenon magnetic resonance of the lung and the brain

    NASA Astrophysics Data System (ADS)

    Venkatesh, Arvind Krishnamachari

    2001-04-01

    Hyperpolarized noble gas Magnetic Resonance Imaging (MRI) is a new diagnostic modality that has been used successfully for lung imaging. Xenon is soluble in blood and inhaled xenon is transported to the brain via circulating blood. Xenon also accumulates in the lipid rich white matter of the brain. Hyperpolarized xenon can hence be used as a tissue- sensitive probe of brain function. The goals of this study were to identify the NMR resonances of xenon in the rat brain and evaluate the role of hyperpolarized xenon for brain MRI. We have developed systems to produce sufficient volumes of hyperpolarized xenon for in vivo brain experiments. The specialized instrumentation developed include an apparatus for optical pump-cell manufacture and high purity gas manifolds for filling cells. A hyperpolarized gas delivery system was designed to ventilate small animals with hyperpolarized xenon for transport to the brain. The T1 of xenon dissolved in blood indicates that the lifetime of xenon in the blood is sufficient for significant magnetization to be transferred to distal tissues. A variety of carrier agents for intravenous delivery of hyperpolarized xenon were tested for transport to distal tissues. Using our new gas delivery system, high SNR 129Xe images of rat lungs were obtained. Spectroscopy with hyperpolarized xenon indicated that xenon was transported from the lungs to the blood and tissues with intact magnetization. After preliminary studies that indicated the feasibility for in vivo rat brain studies, experiments were performed with adult rats and young rats with different stages of white matter development. Both in vivo and in vitro experiments showed the prominence of one peak from xenon in the rat brain, which was assigned to brain lipids. Cerebral brain perfusion was calculated from the wash-out of the hyperpolarized xenon signal in the brain. An increase in brain perfusion during maturation was observed. These experiments showed that hyperpolarized xenon MRI

  7. Coronary artery occlusion extends perfusion territory boundaries through microvascular collaterals.

    PubMed

    Cicutti, N; Rakusan, K; Downey, H F

    1994-01-01

    Simultaneous in vivo infusions of two different colored 10 microns microsphere suspensions into the left anterior descending (LAD; red spheres) and left circumflex (LCx; blue spheres) coronary arteries of nine anesthetized dogs identified a specific region of canine myocardium perfused by both arterial branches. Subsequently, the LAD was ligated and a third (green) set of micropheres was infused into the patent LCx artery. Analysis of 40 microns serial sections of tissue revealed interface zones with capillaries perfused by both arteries. The first zone, defined as the Interface Transistion Zone (ITZ) was formed by an intermingling of microvessels supplied by the parent arteries of the adjacent perfusion territories; it separated tissue containing only one or the other colored microspheres. Another zone, defined as the Boundary Watershed Zone was located within the ITZ and had capillaries containing both red and blue microspheres. The width of ITZ was 53377 +/- 817 microns (mean +/- SD), and the width of the BWZ was 3358 +/- 618 microns. Green microspheres, infused into the LCx following coronary occlusion were also found in the ITZ and BWZ. Furthermore, capillaries perfused exclusively by the LAD before occlusion (tissue with red but not blue microspheres) adjacent to the perfusion interface contained green microspheres as well as red/green aggregates, indicating lateral extension of the LCx perfusion territory. This extension of the LCx territory was quantitated by comparing the location at which densities of green microspheres or green/red aggregates decreased abruptly compared to the location of the original ITZ and BWZ boundaries, respectively. Results showed that LAD occlusion caused a 24% expansion of the ITZ and a 48% expansion of the BWZ. In addition, all expansions were significantly greater in subepicardial compared to subendocardial regions (p < 0.001). These results clearly demonstrate the capability of microvascular anastomoses in providing blood flow

  8. Parametric perfusion imaging based on low-cost ultrasound platform.

    PubMed

    Gu, Xiaolin; Zhong, Hui; Wan, Mingxi; Hu, Xiaowen; Lv, Dan; Shen, Liang; Zhang, Xiaomei

    2010-01-01

    In this study, we attempted to implement parametric perfusion imaging to quantify blood perfusion based on modified low-cost ultrasound platform. A novel ultrasound contrast-specific imaging method called pulse-inversion harmonic sum-squared-differences (PIHSSD) was proposed for improving the sensitivity for detecting contrast agents and the accuracy of parametric perfusion imaging, which combined pulse-inversion harmonic (PIH) with pulse-inversion sum-squared-differences (PISSD) threshold-based decision. PIHSSD method just involved simple operations including addition and multiplication and was easy to realize. The sequences of contrast images without logarithmic compression were used to acquire time intensity curves (TICs) from numerous equal-sized regions-of-interest (ROI) covering the entire image plane. Parametric perfusion images were obtained based on the parameters extracted from the TICs, including peak value (PV), area under curve (AUC), mean transit time (MTT), peak value time (PVT), peak width (PW) and climbing rate (CR). Flow phantom was used for validation and the results suggested that PIHSSD method provided 9.6 to 20.3 dB higher contrast-to-tissue ratio (CTR) than PIH method. The results of the experiments of rabbit kidney also showed that the CTR of PIHSSD images was higher than that of PIH images, and the parametric perfusion images based on PIHSSD method provided more accurate quantification of blood perfusion compared with those based on PIH and PISSD methods. It demonstrated that the parametric perfusion imaging achieved good performance though implemented on low-cost ultrasound platform. (E-mail: mxwan@mail.xjtu.edu.cn). PMID:19931972

  9. The Brains Behind the Brain.

    ERIC Educational Resources Information Center

    D'Arcangelo, Marcia

    1998-01-01

    Interviews with five neuroscientists--Martin Diamond, Pat Wolfe, Robert Sylwester, Geoffrey Caine, and Eric Jensen--disclose brain-research findings of practical interest to educators. Topics include brain physiology, environmental enrichment, memorization, windows of learning opportunity, brain learning capacity, attention span, student interest,…

  10. Regulation of brain copper homeostasis by the brain barrier systems: Effects of Fe-overload and Fe-deficiency

    SciTech Connect

    Monnot, Andrew D.; Behl, Mamta; Ho, Sanna; Zheng, Wei

    2011-11-15

    Maintaining brain Cu homeostasis is vital for normal brain function. The role of systemic Fe deficiency (FeD) or overload (FeO) due to metabolic diseases or environmental insults in Cu homeostasis in the cerebrospinal fluid (CSF) and brain tissues remains unknown. This study was designed to investigate how blood-brain barrier (BBB) and blood-SCF barrier (BCB) regulated Cu transport and how FeO or FeD altered brain Cu homeostasis. Rats received an Fe-enriched or Fe-depleted diet for 4 weeks. FeD and FeO treatment resulted in a significant increase (+ 55%) and decrease (- 56%) in CSF Cu levels (p < 0.05), respectively; however, neither treatment had any effect on CSF Fe levels. The FeD, but not FeO, led to significant increases in Cu levels in brain parenchyma and the choroid plexus. In situ brain perfusion studies demonstrated that the rate of Cu transport into the brain parenchyma was significantly faster in FeD rats (+ 92%) and significantly slower (- 53%) in FeO rats than in controls. In vitro two chamber Transwell transepithelial transport studies using primary choroidal epithelial cells revealed a predominant efflux of Cu from the CSF to blood compartment by the BCB. Further ventriculo-cisternal perfusion studies showed that Cu clearance by the choroid plexus in FeD animals was significantly greater than control (p < 0.05). Taken together, our results demonstrate that both the BBB and BCB contribute to maintain a stable Cu homeostasis in the brain and CSF. Cu appears to enter the brain primarily via the BBB and is subsequently removed from the CSF by the BCB. FeD has a more profound effect on brain Cu levels than FeO. FeD increases Cu transport at the brain barriers and prompts Cu overload in the CNS. The BCB plays a key role in removing the excess Cu from the CSF.

  11. Perfusion imaging with non-contrast ultrasound

    NASA Astrophysics Data System (ADS)

    Tierney, Jaime E.; Dumont, Douglas M.; Byram, Brett C.

    2016-04-01

    A Doppler ultrasound clutter filter that enables estimation of low velocity blood flow could considerably improve ultrasound as a tool for clinical diagnosis and monitoring, including for the evaluation of vascular diseases and tumor perfusion. Conventional Doppler ultrasound is currently used for visualizing and estimating blood flow. However, conventional Doppler is limited by frame rate and tissue clutter caused by involuntary movement of the patient or sonographer. Spectral broadening of the clutter due to tissue motion limits ultrasound's ability to detect blood flow less than about 5mm/s at an 8MHz center frequency. We propose a clutter filtering technique that may increase the sensitivity of Doppler measurements to at least as low as 0.41mm/s. The proposed filter uses an adaptive demodulation scheme that decreases the bandwidth of the clutter. To test the performance of the adaptive demodulation method at removing sonographer hand motion, six volunteer subjects acquired data from a basic quality assurance phantom. Additionally, to test initial in vivo feasibility, an arterial occlusion reactive hyperemia study was performed to assess the efficiency of the proposed filter at preserving signals from blood velocities 2mm/s or greater. The hand motion study resulted in initial average bandwidths of 577Hz (28.5mm/s), which were decreased to 7.28Hz (0.36mm/s) at -60 dB at 3cm using our approach. The in vivo power Doppler study resulted in 15.2dB and 0.15dB dynamic ranges between the lowest and highest blood flow time points for the proposed filter and conventional 50Hz high pass filter, respectively.

  12. Ventilation-perfusion matching during exercise

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.

    1992-01-01

    In normal subjects, exercise widens the alveolar-arterial PO2 difference (P[A-a]O2) despite a more uniform topographic distribution of ventilation-perfusion (VA/Q) ratios. While part of the increase in P(A-a)O2 (especially during heavy exercise) is due to diffusion limitation, a considerable amount is caused by an increase in VA/Q mismatch as detected by the multiple inert gas elimination technique. Why this occurs is unknown, but circumstantial evidence suggests it may be related to interstitial pulmonary edema rather than to factors dependent on ventilation, airway gas mixing, airway muscle tone, or pulmonary vascular tone. In patients with lung disease, the gas exchange consequences of exercise are variable. Thus, arterial PO2 may increase, remain the same, or fall. In general, patients with advanced chronic obstructive pulmonary disease (COPD) or interstitial fibrosis who exercise show a fall in PO2. This is usually not due to worsening VA/Q relationships but mostly to the well-known fall in mixed venous PO2, which itself results from a relatively smaller increase in cardiac output than VO2. However, in interstitial fibrosis (but not COPD), there is good evidence that a part of the fall in PO2 on exercise is caused by alveolar-capillary diffusion limitation of O2 transport; in COPD (but not interstitial fibrosis), a frequent additional contributing factor to the hypoxemia of exercise is an inadequate ventilatory response, such that minute ventilation does not rise as much as does CO2 production or O2 uptake, causing arterial PCO2 to increase and PO2 to fall.

  13. Traumatic brain injury: pathophysiology for neurocritical care.

    PubMed

    Kinoshita, Kosaku

    2016-01-01

    Severe cases of traumatic brain injury (TBI) require neurocritical care, the goal being to stabilize hemodynamics and systemic oxygenation to prevent secondary brain injury. It is reported that approximately 45 % of dysoxygenation episodes during critical care have both extracranial and intracranial causes, such as intracranial hypertension and brain edema. For this reason, neurocritical care is incomplete if it only focuses on prevention of increased intracranial pressure (ICP) or decreased cerebral perfusion pressure (CPP). Arterial hypotension is a major risk factor for secondary brain injury, but hypertension with a loss of autoregulation response or excess hyperventilation to reduce ICP can also result in a critical condition in the brain and is associated with a poor outcome after TBI. Moreover, brain injury itself stimulates systemic inflammation, leading to increased permeability of the blood-brain barrier, exacerbated by secondary brain injury and resulting in increased ICP. Indeed, systemic inflammatory response syndrome after TBI reflects the extent of tissue damage at onset and predicts further tissue disruption, producing a worsening clinical condition and ultimately a poor outcome. Elevation of blood catecholamine levels after severe brain damage has been reported to contribute to the regulation of the cytokine network, but this phenomenon is a systemic protective response against systemic insults. Catecholamines are directly involved in the regulation of cytokines, and elevated levels appear to influence the immune system during stress. Medical complications are the leading cause of late morbidity and mortality in many types of brain damage. Neurocritical care after severe TBI has therefore been refined to focus not only on secondary brain injury but also on systemic organ damage after excitation of sympathetic nerves following a stress reaction. PMID:27123305

  14. Modelling of temperature and perfusion during scalp cooling

    NASA Astrophysics Data System (ADS)

    Janssen, F. E. M.; Van Leeuwen, G. M. J.; Van Steenhoven, A. A.

    2005-09-01

    Hair loss is a feared side effect of chemotherapy treatment. It may be prevented by cooling the scalp during administration of cytostatics. The supposed mechanism is that by cooling the scalp, both temperature and perfusion are diminished, affecting drug supply and drug uptake in the hair follicle. However, the effect of scalp cooling varies strongly. To gain more insight into the effect of cooling, a computer model has been developed that describes heat transfer in the human head during scalp cooling. Of main interest in this study are the mutual influences of scalp temperature and perfusion during cooling. Results of the standard head model show that the temperature of the scalp skin is reduced from 34.4 °C to 18.3 °C, reducing tissue blood flow to 25%. Based upon variations in both thermal properties and head anatomies found in the literature, a parameter study was performed. The results of this parameter study show that the most important parameters affecting both temperature and perfusion are the perfusion coefficient Q10 and the thermal resistances of both the fat and the hair layer. The variations in the parameter study led to skin temperature ranging from 10.1 °C to 21.8 °C, which in turn reduced relative perfusion to 13% and 33%, respectively.

  15. Hyperventilation induces release of cytokines from perfused mouse lung.

    PubMed

    von Bethmann, A N; Brasch, F; Nüsing, R; Vogt, K; Volk, H D; Müller, K M; Wendel, A; Uhlig, S

    1998-01-01

    Artificial mechanical ventilation represents a major cause of iatrogenic lung damage in intensive care. It is largely unknown which mediators, if any, contribute to the onset of such complications. We investigated whether stress caused by artificial mechanical ventilation leads to induction, synthesis, and release of cytokines or eicosanoids from lung tissue. We used the isolated perfused and ventilated mouse lung where frequent perfusate sampling allows determination of mediator release into the perfusate. Hyperventilation was executed with either negative (NPV) or positive pressure ventilation (PPV) at a transpulmonary pressure that was increased 2.5-fold above normal. Both modes of hyperventilation resulted in an approximately 1.75-fold increased expression of tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) mRNA, but not of cyclooxygenase-2 mRNA. After switching to hyperventilation, prostacyclin release into the perfusate increased almost instantaneously from 19 +/- 17 pg/min to 230 +/- 160 pg/min (PPV) or 115 +/- 87 pg/min (NPV). The enhancement in TNFalpha and IL-6 production developed more slowly. In control lungs after 150 min of perfusion and ventilation, TNFalpha and IL-6 production was 23 +/- 20 pg/min and 330 +/- 210 pg/min, respectively. In lungs hyperventilated for 150 min, TNFalpha and IL-6 production were increased to 287 +/- 180 pg/min and more than 1,000 pg/min, respectively. We conclude that artificial ventilation might cause pulmonary and systemic adverse reactions by inducing the release of mediators into the circulation. PMID:9445308

  16. Real-time vascular mechanosensation through ex vivo artery perfusion

    PubMed Central

    2014-01-01

    Background Cell-based perfusion studies have provided great insight into fluid-sensing mechanisms, such as primary cilia in the renal and vascular systems. However, the intrinsic limitations of in vitro cell culture, such as the inability to reflect cellular organization within tissues, has distanced observed paradigms from possible clinical developments. Here we describe a protocol that applies ex vivo artery perfusion and calcium imaging to observe real-time cellular responses to fluid-shear stress. Results Through our ex vivo artery perfusion method, we were able to simulate physiological flow and initiate distinct fluid shear stress mechanosensory responses, as well as induced acetylcholine responses in mouse aortic tissue. The observed calcium profiles confirm results found through previous in vitro cell culture experiments. The overall procedure, including dissection, sample preparation and perfusion, takes around 3 hours to complete. Conclusion Through our unique method, we are able to induce laminar flow within intact mouse aortic tissue and illicit subsequent cellular responses. This method of ex vivo artery perfusion provides the opportunity to bridge the novel findings of in vitro studies with subsequent physiological models of fluid-shear stress mechanosensation in vascular tissues. PMID:24685068

  17. Perfused Multiwell Plate for 3D Liver Tissue Engineering

    PubMed Central

    Domansky, Karel; Inman, Walker; Serdy, James; Dash, Ajit; Lim, Matthew H. M.

    2014-01-01

    In vitro models that capture the complexity of in vivo tissue and organ behaviors in a scalable and easy-to-use format are desirable for drug discovery. To address this, we have developed a bioreactor that fosters maintenance of 3D tissue cultures under constant perfusion and we have integrated multiple bioreactors into an array in a multiwell plate format. All bioreactors are fluidically isolated from each other. Each bioreactor in the array contains a scaffold that supports formation of hundreds of 3D microscale tissue units. The tissue units are perfused with cell culture medium circulated within the bioreactor by integrated pneumatic diaphragm micropumps. Electronic controls for the pumps are kept outside the incubator and connected to the perfused multiwell by pneumatic lines. The docking design and open-well bioreactor layout make handling perfused multiwell plates similar to using standard multiwell tissue culture plates. A model of oxygen consumption and transport in the circulating culture medium was used to predict appropriate operating parameters for primary liver cultures. Oxygen concentrations at key locations in the system were then measured as a function of flow rate and time after initiation of culture to determine oxygen consumption rates. After seven days in culture, tissue formed from cells seeded in the perfused multiwell reactor remained functionally viable as assessed by immunostaining for hepatocyte and liver sinusoidal endothelial cell (LSEC) phenotypic markers. PMID:20024050

  18. Renal vascular perfusion index in a canine model.

    PubMed

    Shau, Yio-Wha; Pao, Sun-Hua; Chou, Nai-Kuan; Chang, King-Jen; Shyu, Jeou-Jong

    2009-01-01

    Decreased renal perfusion plays an important role in the progression toward renal failure. In this study, a novel measure was proposed to quantify renal perfusion using canine model. Serial renal vascular images at different vascular areas including the whole vascular tree, interlobar, arcuate and interlobular vessels were captured. Image processing software was designed to analyze the changes of power Doppler intensity of colored pixels within regions-of-interest (ROI). For a given ROI, the power Doppler vascular index (PDVI) was found to fluctuate with the cardiac cycle. It was also noted that the power Doppler signals generated by arterial vessels have different fluctuating waveforms and different phase compared with the signal derived from venous vessels. A power Doppler correlation-map was developed to differentiate the arteries and veins in the ROI. Using the serial power Doppler images and the derived flow direction information, the interlobular perfusion can be strongly quantified. The renal vascular perfusion index (RVPI) defined as the ratio of PDVI(max) versus PDVI(min) was significantly higher in the interlobular vessel areas than three other areas for seven healthy dogs. The RVPI resembles the systolic/diastolic (S/D) ratio that commonly reflects arterial hemodynamics. RVPI and power Doppler correlation-map reveal more "dynamic" sense of vascular perfusion and provide a novel approach for the examination of renal function in clinical practice. PMID:18805627

  19. Tomographic digital subtraction angiography for lung perfusion estimation in rodents

    SciTech Connect

    Badea, Cristian T.; Hedlund, Laurence W.; De Lin, Ming; Boslego Mackel, Julie S.; Samei, Ehsan; Allan Johnson, G.

    2007-05-15

    In vivo measurements of perfusion present a challenge to existing small animal imaging techniques such as magnetic resonance microscopy, micro computed tomography, micro positron emission tomography, and microSPECT, due to combined requirements for high spatial and temporal resolution. We demonstrate the use of tomographic digital subtraction angiography (TDSA) for estimation of perfusion in small animals. TDSA augments conventional digital subtraction angiography (DSA) by providing three-dimensional spatial information using tomosynthesis algorithms. TDSA is based on the novel paradigm that the same time density curves can be reproduced in a number of consecutive injections of {mu}L volumes of contrast at a series of different angles of rotation. The capabilities of TDSA are established in studies on lung perfusion in rats. Using an imaging system developed in-house, we acquired data for four-dimensional (4D) imaging with temporal resolution of 140 ms, in-plane spatial resolution of 100 {mu}m, and slice thickness on the order of millimeters. Based on a structured experimental approach, we optimized TDSA imaging providing a good trade-off between slice thickness, the number of injections, contrast to noise, and immunity to artifacts. Both DSA and TDSA images were used to create parametric maps of perfusion. TDSA imaging has potential application in a number of areas where functional perfusion measurements in 4D can provide valuable insight into animal models of disease and response to therapeutics.

  20. Potentials and pitfalls using high affinity radioligands in PET and SPET determinations on regional drug induced D2 receptor occupancy--a simulation study based on experimental data.

    PubMed

    Olsson, H; Farde, L

    2001-10-01

    The D2 dopamine receptor density ranges from 0.2 to 40 nM among human brain regions. For high density regions radioligands like [(11)C]raclopride provide accurate and reliable estimates of the receptor density. In research on neuropsychiatric disorders there is, however, a growing need for quantitative approaches that accurately measure D2 dopamine receptor occupancy induced by drugs or endogenous dopamine in regions with low receptor density. The new high affinity radioligands [(11)C]FLB 457 and [(123)I]epidepride have been shown to provide a signal for extrasriatal D2 dopamine receptor populations in the human brain in vivo. Initial observations indicate, however, that the time required to reach equilibrium is dependent on receptor density. Ratio analyses may thus not be readily used for comparisons among different brain regions. The aim of the present simulation study was to examine commonly used approaches for calculation of drug induced D2 dopamine receptor occupancy among regions with widely different receptor density. The input functions and the rate constants of [(11)C]FLB 457 and the reference ligand [(11)C]raclopride were first used in a simulation estimating the effect of receptor density on equilibrium time. In a second step we examined how errors produced by inaccurate determination of the binding potential parameter propagate to calculations of drug induced receptor occupancy. The simulations showed a marked effect of receptor density on equilibrium time for [(11)C]FLB 457, but not for [(11)C]raclopride. For [(11)C]FLB 457, a receptor density above about 7 nM caused the time of equilibrium to fall beyond time of data acquisition (1 h). The use of preequilibrium data caused the peak equilibrium and the end time ratio approaches but not the simplified reference tissue model (SRTM) approach to underestimate the binding potential and thus also the drug occupancy calculated for high-density regions. The study supports the use of ratio and SRTM analyses in

  1. 3-Fluoro-Deoxyglucose for the assessment of cerebral perfusion and glucose transport - Indications for extracranial-intracranial arterial bypass and followup studies

    SciTech Connect

    Mehdorn, H.M.; Vyska, K.; Machulla, H.J.; Knust, E.J.

    1985-05-01

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

  2. Brain tumors.

    PubMed Central

    Black, K. L.; Mazziotta, J. C.; Becker, D. P.

    1991-01-01

    Recent advances in experimental tumor biology are being applied to critical clinical problems of primary brain tumors. The expression of peripheral benzodiazepine receptors, which are sparse in normal brain, is increased as much as 20-fold in brain tumors. Experimental studies show promise in using labeled ligands to these receptors to identify the outer margins of malignant brain tumors. Whereas positron emission tomography has improved the dynamic understanding of tumors, the labeled selective tumor receptors with positron emitters will enhance the ability to specifically diagnose and greatly aid in the pretreatment planning for tumors. Modulation of these receptors will also affect tumor growth and metabolism. Novel methods to deliver antitumor agents to the brain and new approaches using biologic response modifiers also hold promise to further improve the management of brain tumors. Images PMID:1848735

  3. Evaluating acellular versus cellular perfusate composition during prolonged ex vivo lung perfusion after initial cold ischaemia for 24 hours.

    PubMed

    Becker, Simon; Steinmeyer, Jasmin; Avsar, Murat; Höffler, Klaus; Salman, Jawad; Haverich, Axel; Warnecke, Gregor; Ochs, Matthias; Schnapper, Anke

    2016-01-01

    Normothermic ex vivo lung perfusion (EVLP) has developed as a powerful technique to evaluate particularly marginal donor lungs prior to transplantation. In this study, acellular and cellular perfusate compositions were compared in an identical experimental setting as no consensus has been reached on a preferred technique yet. Porcine lungs underwent EVLP for 12 h on the basis of an acellular or a cellular perfusate composition after 24 h of cold ischaemia as defined organ stress. During perfusion, haemodynamic and respiratory parameters were monitored. After EVLP, the lung condition was assessed by light and transmission electron microscopy. Aerodynamic parameters did not show significant differences between groups and remained within the in vivo range during EVLP. Mean oxygenation indices were 491 ± 39 in the acellular group and 513 ± 53 in the cellular group. Groups only differed significantly in terms of higher pulmonary artery pressure and vascular resistance in the cellular group. Lung histology and ultrastructure were largely well preserved after prolonged EVLP and showed only minor structural alterations which were similarly present in both groups. Prolonged acellular and cellular EVLP for 12 h are both feasible with lungs prechallenged by ischaemic organ stress. Physiological and ultrastructural analysis showed no superiority of either acellular or cellular perfusate composition. PMID:26264867

  4. Revival of impaired lung perfusion after sleeve lobectomy

    PubMed Central

    Shibano, Tomoki; Endo, Shunsuke; Yamamoto, Shinichi; Maki, Mitsuru

    2016-01-01

    Sleeve resection, a mainstay for centrally-located lung cancer, is a challenging procedure when the preserved lung is impaired. We herein reported a 61-year-old male who underwent right upper sleeve lobectomy for squamous cell carcinoma located at the orifice of the upper bronchus. The tumor invaded the main bronchus. A lung perfusion scan showed severe impairment, while the right middle and lower lobes were well expanded. Not only the spirogram, but also the lung perfusion in the residual lung, had markedly recovered at 2 months after the right upper extended sleeve lobectomy. The patient is currently living his normal daily life. Residual lung perfusion can be revived, even if it is impaired preoperatively. PMID:27076980

  5. Complete inhibition of creatine kinase in isolated perfused rat hearts

    SciTech Connect

    Fossel, E.T.; Hoefeler, H.

    1987-01-01

    Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts are able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. /sup 31/P-NMR of the heart was carried out.

  6. Testosterone biotransformation by the isolated perfused canine pancreas

    SciTech Connect

    Fernandez-del Castillo, C.; Diaz-Sanchez, V.; Varela-Fascinetto, G.; Altamirano, A.; Odor-Morales, A.; Lopez-Medrano, R.M.; Robles-Diaz, G. )

    1991-01-01

    There is strong evidence indicating that the pancreas is under the influence of sex steroid hormones, and that it may even participate in their biosynthesis and metabolism. In the present study, (3H)testosterone was perfused into the isolated canine pancreas, and measured in the effluent with several of its metabolites (5 alpha-dihydrotestosterone, androstenedione, and estradiol). Results show that testosterone is readily transformed by the canine pancreas. The main product found in the effluent is androstenedione. The testis and spleen were also perfused with (3H)testosterone and used as controls. In both cases, this hormone appeared mostly unchanged in the effluent as compared to the pancreatic perfusion (p less than 0.0001). From our data, we conclude that the canine pancreas has the capacity to transform sex steroid hormones, and could be considered an extragonadal site of sex steroid biosynthesis.

  7. Regional pulmonary perfusion following human heart-lung transplantation

    SciTech Connect

    Lisbona, R.; Hakim, T.S.; Dean, G.W.; Langleben, D.; Guerraty, A.; Levy, R.D. )

    1989-08-01

    Ventilation and perfusion scans were obtained in six subjects who had undergone heart-lung transplantation with consequent denervation of the cardiopulmonary axis. Two of the subjects had developed obliterative bronchiolitis, which is believed to be a form of chronic rejection. Their pulmonary function tests demonstrated airflow obstruction and their scintigraphic studies were abnormal. In the remaining four subjects without obstructive airways disease, ventilation and planar perfusion scans were normal. Single photon emission computed tomography imaging of pulmonary perfusion in these patients revealed a layered distribution of blood flow indistinguishable from that of normal individuals. It is concluded that neurogenic mechanisms have little influence on the pattern of local pulmonary blood flow at rest.

  8. Reversibility of hepatopulmonary syndrome evidenced by serial pulmonary perfusion scan.

    PubMed

    Shijo, H; Sasaki, H; Sakata, H; Kusuhara, H; Ueki, T; Okumura, M

    1993-02-01

    A patient with liver cirrhosis who exhibited marked hypoxemia is presented. An abnormal dilatation of intrapulmonary capillaries was evidenced by perfusion lung scan, contrast-enhanced echocardiography, and histological examinations of lungs. Serial perfusion lung scan disclosed that the radioisotope uptake by extrapulmonary organs was significantly increased and uptake by both lungs was significantly decreased during the state of severer hypoxemia. Shunt quantification method revealed that intrapulmonary right-to-left shunt ratio also paralleled the extent of hypoxemia. The pathophysiology of hepatopulmonary syndrome appeared to involve a reversible intrapulmonary vascular dilatation. The perfusion lung scan could semiquantitate the severity of intrapulmonary vascular dilatation and could offer the efficient method to follow their progress. PMID:8440418

  9. Laser-induced macular holes demonstrate impaired choroidal perfusion

    NASA Astrophysics Data System (ADS)

    Brown, Jeremiah, Jr.; Allen, Ronald D.; Zwick, Harry; Schuschereba, Steven T.; Lund, David J.; Stuck, Bruce E.

    2003-06-01

    Choroidal perfusion was evaluated following the creation of a laser induced macular hole in a nonhuman primate model. Two Rhesus monkeys underwent macular exposures delivered by a Q-switched Nd:YAG laser. The lesions were evaluated with fluorescein angiography and indocyanine green (ICG) angiography . Each lesion produced vitreous hemorrhage and progressed to a full thickness macular hole. ICG angiography revealed no perfusion of the choriocapillaris beneath the lesion centers. Histopathologic evaluation showed replacement of the choriocapillaris with fibroblasts and connective tissue. Nd:YAG, laser-induced macular holes result in long term impairment of choroidal perfusion at the base of the hole due to choroidal scarring and obliteration of the choriocapillaris.

  10. A New Method of Selective, Rapid Cooling of the Brain: An Experimental Study

    SciTech Connect

    Allers, Mats; Boris-Moeller, Fredrik; Lunderquist, Anders; Wieloch, Tadeusz

    2006-04-15

    Purpose. To determine whether retrograde perfusion of cooled blood into one internal jugular vein (IJV) in the pig can selectively reduce the brain temperature without affecting the core body temperature (CBT). Methods. In 7 domestic pigs, the left IJV was catheterized on one side and a catheter placed with the tip immediately below the rete mirabile. Thermistors were placed in both brain hemispheres and the brain temperature continuously registered. Thermistors placed in the rectum registered the CBT. From a catheter in the right femoral vein blood was aspirated with the aid of a roller pump, passed through a cooling device, and infused into the catheter in the left IJV at an initial rate of 200 ml/min. Results. Immediately after the start of the infusion of cooled blood (13.8 deg. C) into the IJV, the right brain temperature started to drop from its initial 37.9 deg. C and reached 32 deg. C within 5 min. By increasing the temperature of the perfusate a further drop in the brain temperature was avoided and the brain temperature could be kept around 32 deg. C during the experiment. In 4 of the animals a heating blanket was sufficient to compensate for the slight drop in CBT during the cooling period. Conclusions. We conclude that brain temperature can be reduced in the pig by retrograde perfusion of the internal jugular vein with cooled blood and that the core body temperature can be maintained with the aid of a heating blanket.

  11. Characterizing potential heart agents with an isolated perfused heart system

    SciTech Connect

    Pendleton, D.B.; Sands, H.; Gallagher, B.M.; Camin, L.L.

    1984-01-01

    The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex is extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood.

  12. Preservation of Donor Hearts Using Hypothermic Oxygenated Perfusion

    PubMed Central

    Michel, Sebastian G.; La Muraglia, Glenn M.; Madariaga, Maria Lucia L.; Titus, James S.; Selig, Martin K.; Farkash, Evan A.; Allan, James S.; Anderson, Lisa M.; Madsen, Joren C.

    2015-01-01

    Background Hypothermic machine perfusion of donor hearts enables continuous aerobic metabolism and washout of toxic metabolic byproducts. We evaluated the effect of machine perfusion on cardiac myocyte integrity in hearts preserved for 4 h in a novel device that provides pulsatile oxygenated hypothermic perfusion (Paragonix Sherpa Perfusion™ Cardiac Transport System). Material/Methods Pig hearts were harvested and stored in Celsior® solution for 4 h using either conventional cold storage on ice (4-h CS, n=6) or the Sherpa device (4-h pulsatile perfusion (PP), n=6). After cold preservation, hearts were evaluated using a non-working heart Langendorff system. Controls (n=3) were reperfused immediately after organ harvest. Biopsies were taken from the apex of the left ventricle before storage, after storage, and after reperfusion to measure ATP content and endothelin-1 in the tissue. Ultrastructural analysis using electron microscopy was performed. Results Four-hour CS, 4-h PP, and control group did not show any significant differences in systolic or diastolic function (+dP/dt, −dP/dt, EDP). Four-hour PP hearts showed significantly more weight gain than 4-h CS after preservation, which shows that machine perfusion led to myocardial edema. Four-hour CS led to higher endothelin-1 levels after preservation, suggesting more endothelial dysfunction compared to 4-h PP. Electron microscopy revealed endothelial cell rupture and damaged muscle fibers in the 4-h CS group after reperfusion, but the cell structures were preserved in the 4-h PP group. Conclusions Hypothermic pulsatile perfusion of donor hearts leads to a better-preserved cell structure compared to the conventional cold storage method. This may lead to less risk of primary graft failure after orthotopic heart transplantation. PMID:25139381

  13. Resting cerebral glucose metabolism and perfusion patterns in women with posttraumatic stress disorder related to sexual assault.

    PubMed

    Kim, Shin-Young; Chung, Young-Ki; Kim, Bom Sahn; Lee, Su Jin; Yoon, Joon-Kee; An, Young-Sil

    2012-03-31

    In the literature, numerous trials using neuroimaging techniques have investigated brain function in patients with post-traumatic stress disorder (PTSD). However, the contrasting results showed that improvements, including in the study design, were required to reach consistent and convincing conclusions. This study evaluated the functional neuroimaging pattern of resting cerebral blood flow and glucose metabolism in patients with PTSD related to sexual assault. Twelve patients were enrolled for both brain single photon emission computed tomography (SPECT) and (18)F-fluorodeoxyglucose positron emission tomography (PET) investigations. All data were analyzed with statistical parametric mapping 2 (SPM2). The PTSD patients showed significant relative decreases in perfusion in the left hippocampus and in the basal ganglia compared with the control group. The PTSD group also had significantly lower cerebral glucosemetabolic activity in the left hippocampus and the superior temporal and precentral gyri than in the control group. These specific patterns of perfusion and glucose metabolism may be closely related to various neurophysiologic symptoms of PTSD. PMID:22464826

  14. Myocardial perfusion as an indicator of graft patency after coronary artery bypass surgery. [Thallium 201

    SciTech Connect

    Kolibash, A.J.; Call, T.D.; Bush, C.A.; Tetalman, M.R.; Lewis, R.P.

    1980-05-01

    Stress and resting myocardial perfusion were assessed in 38 patients who received 96 grafts. Stress perfusion was evaluated with thallium-201 and resting myocardial blood flow distribution with radiolabeled particles. When both stress and rest perfusion were normal, graft patency was 82% (51 of 62 grafts). Graft patency was also high (81%, 13 of 16) in areas where stress perfusion abnormalities resolved or become less apparent at rest. However, when stress perfusion defects remained unchanged at rest, the graf was likely to be occuluded (73%, 11 of 15). Maintenance of normal rest perfusion or improvement of rest perfusion postoperatively was also associated with a high graft patency rate (80%, 35 of 44), whereas the development of new rest perfusion defects postoperatively implied graft occlusion (86%, six of seven).

  15. Static and dynamic assessment of myocardial perfusion by computed tomography.

    PubMed

    Danad, Ibrahim; Szymonifka, Jackie; Schulman-Marcus, Joshua; Min, James K

    2016-08-01

    Recent developments in computed tomography (CT) technology have fulfilled the prerequisites for the clinical application of myocardial CT perfusion (CTP) imaging. The evaluation of myocardial perfusion by CT can be achieved by static or dynamic scan acquisitions. Although both approaches have proved clinically feasible, substantial barriers need to be overcome before its routine clinical application. The current review provides an outline of the current status of CTP imaging and also focuses on disparities between static and dynamic CTPs for the evaluation of myocardial blood flow. PMID:27013250

  16. Pancreas tumor model in rabbit imaged by perfusion CT scans

    NASA Astrophysics Data System (ADS)

    Gunn, Jason; Tichauer, Kenneth; Moodie, Karen; Kane, Susan; Hoopes, Jack; Stewart, Errol E.; Hadway, Jennifer; Lee, Ting-Yim; Pereira, Stephen P.; Pogue, Brian W.

    2013-03-01

    The goal of this work was to develop and validate a pancreas tumor animal model to investigate the relationship between photodynamic therapy (PDT) effectiveness and photosensitizer drug delivery. More specifically, this work lays the foundation for investigating the utility of dynamic contrast enhanced blood perfusion imaging to be used to inform subsequent PDT. A VX2 carcinoma rabbit cell line was grown in the tail of the pancreas of three New Zealand White rabbits and approximately 3-4 weeks after implantation the rabbits were imaged on a CT scanner using a contrast enhanced perfusion protocol, providing parametric maps of blood flow, blood volume, mean transit time, and vascular permeability surface area product.

  17. Perfusion Quality Improvement and the Reduction of Clinical Variability

    PubMed Central

    Stammers, Alfred H.; Trowbridge, Cody C.; Pezzuto, James; Casale, Alfred

    2009-01-01

    Abstract: The purpose of this study was to describe the development and utilization of a perfusion quality improvement program to reduce perfusion-to-perfusion variability in a large multi-center perfusion practice. Phase I of the study included the establishment of a perfusion database using standard spreadsheet format to serve multiple administrative functions including patient and procedure sequencing, predictive algorithms for yearly caseload, summary statistics, and inter-perfusionist comparison. The database used 236 separate variables, including demographic and clinical procedure-related categories. Forty of these variables are modifiable by perfusion interaction as established via protocol and algorithm. Phase II of the study used a perfusion electronic data recording system to automatically obtain patient data from physiologic monitors and the heart-lung machine. Data were transferred to a central database for perfusionist comparison. Data analysis used logical functions and macros programming, and statistical analysis used both parametric and non-parametric models within the program. Each quarter all variables underwent analysis with summary data established for the most recent 225 patients undergoing CPB. Twenty-five cases from each perfusionist (n = 9) were compared with the aggregate data of the entire staff, with reference to previous quarter’s summary statistics. The results were discussed in monthly staff meetings and methods for improving compliance were discussed. Individual variation (p < .01) varied in 17 of 40 variables (26.0 ± 8.6), with quarterly improvement (27.4 ± 2.3 vs. 24.2 ± 2.1 vs. 17.0 ± 2.1) demonstrated in seven of nine individuals. In Phase II, performance was analyzed using the same variables as in Phase I but it also included the electronically recorded data from which 27 core measures were derived. All results were discussed with the staff at monthly departmental quality improvement meetings. The perfusion quality

  18. Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health

    PubMed Central

    Stephen, Ian D.; Coetzee, Vinet; Law Smith, Miriam; Perrett, David I.

    2009-01-01

    Skin blood perfusion and oxygenation depends upon cardiovascular, hormonal and circulatory health in humans and provides socio-sexual signals of underlying physiology, dominance and reproductive status in some primates. We allowed participants to manipulate colour calibrated facial photographs along empirically-measured oxygenated and deoxygenated blood colour axes both separately and simultaneously, to optimise healthy appearance. Participants increased skin blood colour, particularly oxygenated, above basal levels to optimise healthy appearance. We show, therefore, that skin blood perfusion and oxygenation influence perceived health in a way that may be important to mate choice. PMID:19337378

  19. Myocardial Perfusion Scintigraphy: Techniques, Interpretation, Indications and Reporting

    PubMed Central

    Fathala, Ahmed

    2011-01-01

    Myocardial perfusion single photon emission-computed tomography (MPS) has been one of the most important and common non-invasive diagnostic cardiac test. Gated MPS provides simultaneous assessment of myocardial perfusion and function with only one study. With appropriate attention to the MPS techniques, appropriate clinical utilization and effective reporting, gated MPS will remain a useful diagnostic test for many years to come. The aim of this article is to review the basic techniques of MPS, a simplified systematic approach for study interpretation, current clinical indications and reporting. After reading this article the reader should develop an understanding of the techniques, interpretation, current clinical indications and reporting of MPS studies. PMID:22048510

  20. Perfusion Electronic Record Documentation Using Epic Systems Software

    PubMed Central

    Steffens, Thomas G.; Gunser, John M.; Saviello, George M.

    2015-01-01

    Abstract: This paper describes the design and use of Epic Systems software for documentation of perfusion activities as part of the patient electronic medical record. The University of Wisconsin Hospital and Clinics adapted the Anesthesia software module and developed an integrated perfusion/anesthesia record for the documentation of cardiac and non-cardiac surgical procedures. This project involved multiple committees, approvals, and training to successfully implement. This article will describe our documentation options, concepts, design, challenges, training, and implementation during our initial experience. PMID:26834288

  1. Vascular Tissue Engineering: Building Perfusable Vasculature for Implantation

    PubMed Central

    Gui, Liqiong; Niklason, Laura E.

    2014-01-01

    Tissue and organ replacement is required when there are no alternative therapies available. Although vascular tissue engineering was originally developed to meet the clinical demands of small-diameter vascular conduits as bypass grafts, it has evolved into a highly advanced field where perfusable vasculatures are generated for implantation. Herein, we review several cutting-edge techniques that have led to implantable human blood vessels in clinical trials, the novel approaches that build complex perfusable microvascular networks in functional tissues, the use of stem cells to generate endothelial cells for vascularization, as well as the challenges in bringing vascular tissue engineering technologies into the clinics. PMID:24533306

  2. Uptake of free choline by isolated perfused rat liver.

    PubMed Central

    Zeisel, S H; Story, D L; Wurtman, R J; Brunengraber, H

    1980-01-01

    The uptake of free choline by isolated perfused rat liver was characterized. A saturable uptake mechanism [Ka = 0.17 +/- 0.07 mM (SD); Vmax = 0.84 +/- 0.16 mumol/min X g dry weight] and a nonsaturable mechanism (through which uptake is proportional to choline concentration in the perfusate) were identified. Most of the choline transported into hepatocytes was converted to betaine, phosphorylcholine, or lecithin. Free choline also accumulated within the intracellular space, suggesting that choline oxidase activity does not always limit choline's uptake by the liver. PMID:6933493

  3. ACUTE INDUCTION OF EPILEPTIFORM DISCHARGES BY PILOCARPINE IN THE IN VITRO ISOLATED GUINEA-PIG BRAIN REQUIRES ENHANCEMENT OF BLOOD–BRAIN BARRIER PERMEABILITY

    PubMed Central

    UVA, L.; LIBRIZZI, L.; MARCHI, N.; NOE, F.; BONGIOVANNI, R.; VEZZANI, A.; JANIGRO, D.; DE CURTIS, M.

    2008-01-01

    Systemic application of the muscarinic agonist, pilocarpine, is commonly utilized to induce an acute status epilepticus that evolves into a chronic epileptic condition characterized by spontaneous seizures. Recent findings suggest that the status epilepticus induced by pilocarpine may be triggered by changes in the blood–brain barrier (BBB) permeability. We tested the role of the BBB in an acute pilocarpine model by using the in vitro model brain preparation and compared our finding with in vivo data. Arterial perfusion of the in vitro isolated guinea-pig brain with <1 mM pilocarpine did not cause epileptiform activity, but rather reduced synaptic transmission and induced steady fast (20–25 Hz) oscillatory activity in limbic cortices. These effects were reversibly blocked by co-perfusion of the muscarinic antagonist atropine sulfate (5 μM). Brain pilocarpine measurements in vivo and in vitro suggested modest BBB penetration. Pilocarpine induced epileptiform discharges only when perfused with compounds that enhance BBB permeability, such as bradykinin (n=2) or histamine (n=10). This pro-epileptic effect was abolished when the BBB-impermeable muscarinic antagonist atropine methyl bromide (5 μM) was co-perfused with histamine and pilocarpine. In the absence of BBB permeability enhancing drugs, pilocarpine induced epileptiform activity only after arterial perfusion at concentrations >10 mM. Ictal discharges correlated with a high intracerebral pilocarpine concentration measured by high pressure liquid chromatography. We propose that acute epileptiform discharges induced by pilocarpine treatment in the in vitro isolated brain preparation are mediated by a dose-dependent, atropine-sensitive muscarinic effect promoted by an increase in BBB permeability. Pilocarpine accumulation secondary to BBB permeability changes may contribute to in vivo ictogenesis in the pilocarpine epilepsy model. PMID:18082973

  4. High-frequency Electrocardiogram Analysis in the Ability to Predict Reversible Perfusion Defects during Adenosine Myocardial Perfusion Imaging

    NASA Technical Reports Server (NTRS)

    Tragardh, Elin; Schlegel, Todd T.; Carlsson, Marcus; Pettersson, Jonas; Nilsson, Klas; Pahlm, Olle

    2007-01-01

    Background: A previous study has shown that analysis of high-frequency QRS components (HF-QRS) is highly sensitive and reasonably specific for detecting reversible perfusion defects on myocardial perfusion imaging (MPI) scans during adenosine. The purpose of the present study was to try to reproduce those findings. Methods: 12-lead high-resolution electrocardiogram recordings were obtained from 100 patients before (baseline) and during adenosine Tc-99m-tetrofosmin MPI tests. HF-QRS were analyzed regarding morphology and changes in root mean square (RMS) voltages from before the adenosine infusion to peak infusion. Results: The best area under the curve (AUC) was found in supine patients (AUC=0.736) in a combination of morphology and RMS changes. None of the measurements, however, were statistically better than tossing a coin (AUC=0.5). Conclusion: Analysis of HF-QRS was not significantly better than tossing a coin for determining reversible perfusion defects on MPI scans.

  5. Non-contact tissue perfusion and oxygenation imaging using a LED based multispectral and a thermal imaging system, first results of clinical intervention studies

    NASA Astrophysics Data System (ADS)

    Klaessens, John H. G. M.; Nelisse, Martin; Verdaasdonk, Rudolf M.; Noordmans, Herke Jan

    2013-03-01

    During clinical interventions objective and quantitative information of the tissue perfusion, oxygenation or temperature can be useful for the surgical strategy. Local (point) measurements give limited information and affected areas can easily be missed, therefore imaging large areas is required. In this study a LED based multispectral imaging system (MSI, 17 different wavelengths 370nm-880nm) and a thermo camera were applied during clinical interventions: tissue flap transplantations (ENT), local anesthetic block and during open brain surgery (epileptic seizure). The images covered an area of 20x20 cm, when doing measurements in an (operating) room, they turned out to be more complicated than laboratory experiments due to light fluctuations, movement of the patient and limited angle of view. By constantly measuring the background light and the use of a white reference, light fluctuations and movement were corrected. Oxygenation concentration images could be calculated and combined with the thermal images. The effectively of local anesthesia of a hand could be predicted in an early stage using the thermal camera and the reperfusion of transplanted skin flap could be imaged. During brain surgery, a temporary hyper-perfused area was witnessed which was probably related to an epileptic attack. A LED based multispectral imaging system combined with thermal imaging provide complementary information on perfusion and oxygenation changes and are promising techniques for real-time diagnostics during clinical interventions.

  6. Brain Diseases

    MedlinePlus

    ... know what causes some brain diseases, such as Alzheimer's disease. The symptoms of brain diseases vary widely depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines, or physical therapy can correct the source of the problem or ...

  7. How to monitor the brain in septic patients?

    PubMed

    Oddo, M; Taccone, F S

    2015-07-01

    Brain injury is frequently observed after sepsis and may be primarily related to the direct effects of the septic insult on the brain (e.g., brain edema, ischemia, seizures) or to secondary/indirect injuries (e.g., hypotension, hypoxemia, hypocapnia, hyperglycemia). Management of brain injury in septic patients is first focused to exclude structural intracranial complications (e.g., ischemic/hemorrhagic stroke) and possible confounders (e.g., electrolyte alterations or metabolic disorders, such as dysglycemia). Sepsis-associated brain dysfunction is frequently a heterogeneous syndrome. Despite increasing understanding of main pathophysiologic determinants, therapy is essentially limited to protect the brain against further cerebral damage, by way of "simple" therapeutic manipulations of cerebral perfusion and oxygenation and by avoiding over-sedation. Non-invasive monitoring of cerebral perfusion and oxygenation with transcranial Doppler (TCD) and near-infrared spectroscopy (NIRS) is feasible in septic patients. Electroencephalography (EEG) allows detection of sepsis-related seizures and holds promise also as sedation monitoring. Brain CT-scan detects intra-cerebral structural lesions, while magnetic resonance imaging (MRI) provides important insights into primary mechanisms of sepsis-related direct brain injury, (e.g., cytotoxic vs. vasogenic edema) and the development of posterior reversible encephalopathy. Together with EEG and evoked potentials (EP), MRI is also important for coma prognostication. Emerging clinical evidence suggests monitoring of the brain in septic patients can be implemented in the ICU. The objective of this review was to summarize recent clinical data about the role of brain monitoring - including TCD, NIRS, EEG, EP, CT, and MRI - in patients with sepsis and to illustrate its potential utility for the diagnosis, management and prognostication. PMID:25812488

  8. 21 CFR 876.5880 - Isolated kidney perfusion and transport system and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Isolated kidney perfusion and transport system and....5880 Isolated kidney perfusion and transport system and accessories. (a) Identification. An isolated kidney perfusion and transport system and accessories is a device that is used to support a donated or...

  9. 21 CFR 876.5880 - Isolated kidney perfusion and transport system and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Isolated kidney perfusion and transport system and....5880 Isolated kidney perfusion and transport system and accessories. (a) Identification. An isolated kidney perfusion and transport system and accesssories is a device that is used to support a donated or...

  10. 21 CFR 876.5880 - Isolated kidney perfusion and transport system and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Isolated kidney perfusion and transport system and....5880 Isolated kidney perfusion and transport system and accessories. (a) Identification. An isolated kidney perfusion and transport system and accessories is a device that is used to support a donated or...

  11. 21 CFR 876.5880 - Isolated kidney perfusion and transport system and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Isolated kidney perfusion and transport system and....5880 Isolated kidney perfusion and transport system and accessories. (a) Identification. An isolated kidney perfusion and transport system and accesssories is a device that is used to support a donated or...

  12. 21 CFR 876.5880 - Isolated kidney perfusion and transport system and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Isolated kidney perfusion and transport system and....5880 Isolated kidney perfusion and transport system and accessories. (a) Identification. An isolated kidney perfusion and transport system and accesssories is a device that is used to support a donated or...

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

    PubMed

    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. PMID:26327608

  14. [Multimodal neuromonitoring in traumatic brain injury: contribution of PTiO2].

    PubMed

    Domínguez-Berrot, A M; González-Vaquero, M; Díaz-Domínguez, F J; Robla-Costales, J

    2014-11-01

    The main goal of exhaustively monitoring neurocritical patients is to avoid secondary injury. In the last few years we have witnessed an increase in brain monitoring tools, beyond the checking of intracranial and brain perfusion pressures. These widely used systems offer valuable but possibly insufficient information. Awareness and correction of brain hypoxia is a useful and interesting measure, not only for diagnostic purposes but also when deciding treatment, and to predict an outcome. In this context, it would be of great interest to use all the information gathered from brain oxygenation monitoring systems in conjunction with other available multimodal monitoring devices, in order to offer individualized treatment for each patient. PMID:24793091

  15. Role of Extracranial Carotid Duplex and Computed Tomography Perfusion Scanning in Evaluating Perfusion Status of Pericarotid Stenting

    PubMed Central

    Lin, Chih-Ming; Chang, Yu-Jun; Liu, Chi-Kuang; Yu, Cheng-Sheng

    2016-01-01

    Carotid stenting is an effective treatment of choice in terms of treating ischemic stroke patients with concomitant carotid stenosis. Though computed tomography perfusion scan has been recognized as a standard tool to monitor/follow up this group of patients, not everyone could endure due to underlying medical illness. In contrast, carotid duplex is a noninvasive assessment tool and could track patient clinical condition in real time. In this study we found that “resistance index” of the carotid ultrasound could detect flow changes before and after the stenting procedure, thus having great capacity to replace the role of computed tomography perfusion exam. PMID:27051669

  16. SPECT study of low intensity He-Ne laser intravascular irradiation therapy for brain infarction

    NASA Astrophysics Data System (ADS)

    Xiao, Xue-Chang; Dong, Jia-Zheng; Chu, Xiao-Fan; Jia, Shao-Wei; Liu, Timon C.; Jiao, Jian-Ling; Zheng, Xi-Yuan; Zhou, Ci-Xiong

    2003-12-01

    We used single photon emission computed tomography (SPECT) in brain perfusion imaging to study the changes of regional cerebral blood flow (rCBF) and cerebral function in brain infarction patients treated with intravascular laser irradiation of blood (ILIB). 17 of 35 patients with brain infarction were admitted to be treated by ILIB on the base of standard drug therapy, and SPECT brain perfusion imaging was performed before and after ILIB therapy with self-comparison. The results were analyzed in quantity with brain blood flow function change rate (BFCR%) model. Effect of ILIB during the therapy process in the other 18 patients were also observed. In the 18 patients, SPECT indicated an improvement of rCBF (both in focus and in total brain) and cerebral function after a 30 min-ILIB therapy. And the 17 patients showed an enhancement of total brain rCBF and cerebral function after ILIB therapy in comparison with that before, especially for the focus side of the brain. The enhancement for focus itself was extremely obvious with a higher significant difference (P<0.0001). The mirror regions had no significant change (P>0.05). BFCR% of foci was prominently higher than that of mirror regions (P<0.0001). In conclusion, the ILIB therapy can improve rCBF and cerebral function and activate brain cells of patients with brain infarction. The results denote new evidence of ILIB therapy for those patients with cerebral ischemia.

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

    PubMed Central

    Teng, Michael Mu Huo; Cho, I-Chieh; Kao, Yi-Hsuan; Chuang, Chi-Shuo; Chiu, Fang-Ying; Chang, Feng-Chi

    2013-01-01

    Objective. To improve the quantitative assessment of cerebral blood volume (CBV) and flow (CBF) in the brain voxels from MR perfusion images. Materials and Methods. Normal brain parenchyma was automatically segmented with the time-to-peak criteria after cerebrospinal fluid removal and preliminary vessel voxel removal. Two scaling factors were calculated by comparing the relative CBV and CBF of the segmented normal brain parenchyma with the absolute values in the literature. Using the scaling factors, the relative values were converted to the absolute CBV and CBF. Voxels with either CBV > 8 mL/100 g or CBF > 100 mL/100 g/min were characterized as vessel voxels and were excluded from the quantitative measurements. Results. The segmented brain parenchyma with normal perfusion was consistent with the angiographic findings for each patient. We confirmed the necessity of dual thresholds including CBF and CBV for proper removal of vessel voxels. The scaling factors were 0.208 ± 0.041 for CBV, and 0.168 ± 0.037, 0.172 ± 0.037 for CBF calculated using standard and circulant singular value decomposition techniques, respectively. Conclusion. The automatic scaling and vessel removal techniques provide an alternative method for obtaining improved quantitative assessment of CBV and CBF in patients with thromboembolic cerebral arterial disease. PMID:23586033

  18. Electroencephalography reveals lower regional blood perfusion and atrophy of the temporoparietal network associated with memory deficits and hippocampal volume reduction in mild cognitive impairment due to Alzheimer’s disease

    PubMed Central

    Moretti, Davide Vito

    2015-01-01

    Background An increased electroencephalographic (EEG) upper/lower alpha power ratio has been associated with less regional blood perfusion, atrophy of the temporoparietal region of the brain, and reduction of hippocampal volume in subjects affected by mild cognitive impairment due to Alzheimer’s disease as compared with subjects who do not develop the disease. Moreover, EEG theta frequency activity is quite different in these groups. This study investigated the correlation between biomarkers and memory performance. Methods EEG α3/α2 power ratio and cortical thickness were computed in 74 adult subjects with prodromal Alzheimer’s disease. Twenty of these subjects also underwent assessment of blood perfusion by single-photon emission computed tomography (SPECT). Pearson’s r was used to assess the correlation between cortical thinning, brain perfusion, and memory impairment. Results In the higher α3/α2 frequency power ratio group, greater cortical atrophy and lower regional perfusion in the temporoparietal cortex was correlated with an increase in EEG theta frequency. Memory impairment was more pronounced in the magnetic resonance imaging group and SPECT groups. Conclusion A high EEG upper/low alpha power ratio was associated with cortical thinning and less perfusion in the temporoparietal area. Moreover, atrophy and less regional perfusion were significantly correlated with memory impairment in subjects with prodromal Alzheimer’s disease. The EEG upper/lower alpha frequency power ratio could be useful for identifying individuals at risk for progression to Alzheimer’s dementia and may be of value in the clinical context. PMID:25750526

  19. Ventilation-perfusion scintiscanning in tropical pulmonary eosinophilia.

    PubMed

    Ray, D; Jayachandran, C A

    1993-08-01

    We report the findings of ventilation and perfusion scintiscanning performed in three untreated patients with acute tropical pulmonary eosinophilia (TPE). In a 26-year-old man whose arterial blood gas values were normal, the lung scan showed normal radioactivity. The scintigrams of a 20-year-old woman who had hypoxemia and hypercapnea showed gross ventilation defects of both lungs that were mainly mismatched; changes in the perfusion scan were minimal. Scintiscanning in a 14-year-old girl who had moderate arterial hypoxia and mild hypocapnea, on the other hand, showed ventilation defects in both lungs, more marked in left lung; multiple matching ventilation-perfusion defects were also seen; however, the V/Q defects did not appear to be equally matched. The scintigraphic findings were compatible with arterial blood gas status of the individual patients and consistent with the notion that a disturbed ventilation-perfusion relationship may be responsible for hypoxemia in some of the patients with TPE. PMID:8339640

  20. Hypothermic Machine Perfusion Preservation of the DCD Kidney: Machine Effects

    PubMed Central

    Lindell, Susanne L.; Muir, Heather; Brassil, John; Mangino, Martin J.

    2013-01-01

    Purpose. Kidneys from DCD donors represent a significant pool, but preservation problems exist. The study objective was to test the importance of machine type for hypothermic preservation of DCD kidneys. Methods. Adult Beagle dog kidneys underwent 45 minutes of warm in situ ischemia followed by hypothermic perfusion for 24 hours (Belzer-MPS Solution) on either an ORS LifePort or a Waters RM3 using standard perfusion protocols. Kidneys were then autotransplanted, and renal function was assessed over 7 days following contralateral nephrectomy. Results. Renal vascular resistance was not different between the two pumps. After 24 hours, the oxygen partial pressure and oxygen delivery in the LifePort perfusate were significantly lower than those in the RM3 but not low enough to change lactate production. TheLifePort ran significantly colder than RM3 (2° versus 5°C). The arterial pressure waveform of the RM3 was qualitatively different from the waveform of the LifePort. Preservation injury after transplantation was not different between the devices. When the LifePort was changed to nonpulsatile flow, kidneys displayed significantly greater preservation injury compared to RM3. Conclusions. Both LifePort and RM3 can be used for hypothermic machine perfusion preservation of DCD kidneys with equal outcomes as long as the duty cycle remains pulsatile. PMID:24222842

  1. Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging

    SciTech Connect

    Baillet, G.Y.; Mena, I.G.; Kuperus, J.H.; Robertson, J.M.; French, W.J.

    1989-01-01

    Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

  2. Determination of regional myocardial perfusion by x-ray fluorescence.

    PubMed

    Palmer, B M; McInerney, J J

    1990-05-01

    Validation studies were performed to demonstrate the effectiveness of an x-ray induced fluorescence system in quantitating regional myocardial perfusion in vivo. In a series of 13 open-chested canines, x-ray induced fluorescence was used to simultaneously monitor iodine concentration transients which arose in the left ventricular lumen and in the myocardium after the intravenous injection of an iodinated flow tracer. Deconvolution of the recorded transients produced a transfer function from which the mean transit time for the tracer to travel between the left ventricular lumen and the myocardium was calculated. Measurements of regional myocardial perfusion (Q) made by radioactive microspheres were compared with the reciprocals of the mean transit times (MTT-1) and gave a linear correlation (n = 38): MTT-1 = 0.033 + 0.069 Q, r = 0.71. Comparison of the percent change in perfusion (dQ) relative to a control study for each dog with the percent change in the respective reciprocals of the mean transit times (dMTT-1) produced a linear correlation coefficient of r = 0.88 for the regression line dMTT-1 = 0.46 dQ - 10.7. The x-ray induced fluorescence system may provide a minimally invasive means for monitoring iodine concentration transients and determining relative, if not absolute, measures of regional myocardial perfusion. PMID:2345078

  3. Teaching Ventilation/Perfusion Relationships in the Lung

    ERIC Educational Resources Information Center

    Glenny, Robb W.

    2008-01-01

    This brief review is meant to serve as a refresher for faculty teaching respiratory physiology to medical students. The concepts of ventilation and perfusion matching are some of the most challenging ideas to learn and teach. Some strategies to consider in teaching these concepts are, first, to build from simple to more complex by starting with a…

  4. Postresection bronchopleural fistula: detection by regional ventilation-perfusion studies

    SciTech Connect

    Dixon, C.; Ali, M.K.; Atallah, M.R.; Ewer, M.S.

    1983-04-01

    In three patients, bronchopleural fistula developed after right pneumonectomy for bronchogenic carcinoma. In each instance, radiologic and clinical evidence was inconclusive. Xenon 133 regional ventilation-perfusion studies confirmed the diagnosis of a bronchopleural fistula in both the immediate and late postoperative periods.

  5. Ex Vivo Perfusion Treatment of Infection in Human Donor Lungs.

    PubMed

    Nakajima, D; Cypel, M; Bonato, R; Machuca, T N; Iskender, I; Hashimoto, K; Linacre, V; Chen, M; Coutinho, R; Azad, S; Martinu, T; Waddell, T K; Hwang, D M; Husain, S; Liu, M; Keshavjee, S

    2016-04-01

    Ex vivo lung perfusion (EVLP) is a platform to treat infected donor lungs with antibiotic therapy before lung transplantation. Human donor lungs that were rejected for transplantation because of clinical concern regarding infection were randomly assigned to two groups. In the antibiotic group (n = 8), lungs underwent EVLP for 12 h with high-dose antibiotics (ciprofloxacin 400 mg or azithromycin 500 mg, vancomycin 15 mg/kg, and meropenem 2 g). In the control group (n = 7), lungs underwent EVLP for 12 h without antibiotics. A quantitative decrease in bacterial counts in bronchoalveolar lavage (BAL) was found in all antibiotic-treated cases but in only two control cases. Perfusate endotoxin levels at 12 h were significantly lower in the antibiotic group compared with the control group. EVLP with broad-spectrum antibiotic therapy significantly improved pulmonary oxygenation and compliance and reduced pulmonary vascular resistance. Perfusate endotoxin levels at 12 h were strongly correlated with levels of perfusates tumor necrosis factor α, IL-1β and macrophage inflammatory proteins 1α and 1β at 12 h. In conclusion, EVLP treatment of infected donor lungs with broad-spectrum antibiotics significantly reduced BAL bacterial counts and endotoxin levels and improved donor lung function. PMID:26730551

  6. FATE OF INHALED NITROGEN DIOXIDE IN ISOLATED PERFUSED RAT LUNG

    EPA Science Inventory

    The fate of inhaled NO2 was studied with isolated perfused rat lungs. The isolated lungs were exposed to 5 ppm NO2 for 90 min at a ventilation rate of 45 ml/min. The NO2 exposure had no adverse effects on the lungs as judged from their weights, glucose uptake, or lactate producti...

  7. Intensity correlation of ventilation-perfusion lung images

    NASA Astrophysics Data System (ADS)

    Costa, Antonio A.; Vaz de Carvalho, Carlos; Seixas, M.; Ferreira, F. N.; Guedes, M. A.; Amaral, I.

    1993-07-01

    The purpose of this study is to develop a method to create new images, based on lung verification and perfusion raw nuclear medicine images obtained from a gamma camera, that may help the correlation of their intrinsic information. Another major topic of this study is the assessment of the usefulness of this method in the detection of lung malfunction.

  8. Pulsatile roller pump perfusion is safe in high risk patients.

    PubMed

    Kocakulak, M; Küçükaksu, S; Pişkin, E

    2004-05-01

    In this study, controllability, safety, blood cell depletion, and hemolysis of a pulsatile roller pump in high-risk patients was evaluated. Sarns 8000 roller pump (Sams, Terumo CVS, Ann Arbor, MI, USA) with a pulsatile control module was used as arterial pump in a clinical setting. Forty patients undergoing elective open heart surgery with high-risk either having chronically obstructive pulmonary disease or chronic renal failure were randomly included in the study to be operated on using pulsatile perfusion or non-pulsatile perfusion. Blood samples were withdrawn at induction of anesthesia, at the time of aortic clamping and de-clamping and at 1 hour and 24 hours following cessation of the bypass. Hematocrit and plasma free hemoglobin values were measured. We observed that the pulsatile roller pump perfusion and the extracorporeal circuit used in the clinical study is safe in high-risk patients undergoing cardiopulmonary bypass. We did not face any emboli, hemolysis, or technical problems. Pulsatile roller pump perfusion with Sarns 8000 heart-lung machine is a simple and reliable technique and can be easily applied during open heart surgery. PMID:15202823

  9. Perfusion from angiogram and a priori (PAP) with temporal regularization

    NASA Astrophysics Data System (ADS)

    Taguchi, Katsuyuki; Geschwind, Jean-Francois H.

    2009-02-01

    Perfusion imaging is often used for diagnosis and for assessment of the response to the treatment. If perfusion can be measured during interventional procedures, it could lead to quantitative, more efficient and accurate treatment; however, imaging modalities that allow continuous dynamic scanning are not available in most of procedure rooms. Thus, we developed a method to measure the perfusion-time attenuation curves (TACs)-of regions-of-interest (ROIs) using xray C-arm angiography system with no gantry rotation but with a priori. The previous study revealed a problem of large oscillations in the estimated TACs and the lack of comparison with CT-based approaches. Thus the purposes of this study were (1) to reduce the variance of TDCs; and (2) to compare the performance of the improved PAP with that of the CT-based perfusion method. Our computer simulation study showed that the standard deviation of PAP method was decreased by 10.7-59.0% and that it outperformed (20× or 200× times) higher dose CT methods in terms of the accuracy, variance, and the temporal resolution.

  10. Brain investigation and brain conceptualization

    PubMed Central

    Redolfi, Alberto; Bosco, Paolo; Manset, David; Frisoni, Giovanni B.

    Summary The brain of a patient with Alzheimer’s disease (AD) undergoes changes starting many years before the development of the first clinical symptoms. The recent availability of large prospective datasets makes it possible to create sophisticated brain models of healthy subjects and patients with AD, showing pathophysiological changes occurring over time. However, these models are still inadequate; representations are mainly single-scale and they do not account for the complexity and interdependence of brain changes. Brain changes in AD patients occur at different levels and for different reasons: at the molecular level, changes are due to amyloid deposition; at cellular level, to loss of neuron synapses, and at tissue level, to connectivity disruption. All cause extensive atrophy of the whole brain organ. Initiatives aiming to model the whole human brain have been launched in Europe and the US with the goal of reducing the burden of brain diseases. In this work, we describe a new approach to earlier diagnosis based on a multimodal and multiscale brain concept, built upon existing and well-characterized single modalities. PMID:24139654

  11. Clearance of Immunoreactive Somatostatin by Perfused Rat Liver

    PubMed Central

    Sacks, Harold; Terry, L. Cass

    1981-01-01

    Other investigators have demonstrated that concentrations of immunoreactive somatostatin (IRS) are higher in blood from the hepatic portal vein or its tributaries than in blood from the hepatic or peripheral systemic veins of man and animals. This suggests that there is hepatic extraction of IRS from the portal system in vivo. In the rat, portal vein plasma IRS is reported to be heterogeneous and to contain, in part, a 1,600 mol wt form of IRS which is immunochemically similar to synthetic somatostatin and not significantly bound to high molecular weight plasma protein. Our study was undertaken to determine directly whether unbound synthetic cyclic somatostatin was cleared by the rat liver perfused through the hepatic portal vein in vitro with a recirculating, plasma-free, erythrocyte-containing perfusate. At 37°C and pH 7.40, perfusate IRS, at initial concentrations (1,728 pg/ml) within the range previously reported in rat portal venous blood, was removed by the liver at a rate commensurate with first-order kinetics. Hepatic clearance was 0.84±0.04 ml/min per g postperfusion wet weight (SE). Hepatic extraction was 36±2%, and t½ was 20.0±1.3 min. Recovery of IRS from the perfusate without the liver was >85%, excluding significant degradation by the medium. Clearance, extraction, and t½ of IRS were not changed by an unphysiologic IRS concentration (621,500 pg/ml), or by pharmacologic concentrations of insulin (8.2 μM) or glucagon (2.9 μM). The t½ was prolonged significantly to 28.2±1.9 and 45.6±4.7 min during perfusions at liver temperatures of 25° and 16°C, respectively. At 37°C, the t½ was also significantly increased to 28.7±3.2 and 24.2±1.1 min at perfusate pH 7.06 and 6.78, respectively. These studies indicate that the rat liver clears unbound IRS from the perfusate by a first-order kinetic process that is (a) unsaturable at pharmacologic concentrations, (b) temperature-sensitive and, to a lesser extent, influenced by lowered pH, and (c) not

  12. Reversing brain damage in former NFL players: implications for traumatic brain injury and substance abuse rehabilitation.

    PubMed

    Amen, Daniel G; Wu, Joseph C; Taylor, Derek; Willeumier, Kristen

    2011-01-01

    Brain injuries are common in professional American football players. Finding effective rehabilitation strategies can have widespread implications not only for retired players but also for patients with traumatic brain injury and substance abuse problems. An open label pragmatic clinical intervention was conducted in an outpatient neuropsychiatric clinic with 30 retired NFL players who demonstrated brain damage and cognitive impairment. The study included weight loss (if appropriate); fish oil (5.6 grams a day); a high-potency multiple vitamin; and a formulated brain enhancement supplement that included nutrients to enhance blood flow (ginkgo and vinpocetine), acetylcholine (acetyl-l-carnitine and huperzine A), and antioxidant activity (alpha-lipoic acid and n-acetyl-cysteine). The trial average was six months. Outcome measures were Microcog Assessment of Cognitive Functioning and brain SPECT imaging. In the retest situation, corrected for practice effect, there were statistically significant increases in scores of attention, memory, reasoning, information processing speed and accuracy on the Microcog. The brain SPECT scans, as a group, showed increased brain perfusion, especially in the prefrontal cortex, parietal lobes, occipital lobes, anterior cingulate gyrus and cerebellum. This study demonstrates that cognitive and cerebral blood flow improvements are possible in this group with multiple interventions. PMID:21615001

  13. Prognostic value of quantitative high-speed myocardial perfusion imaging

    PubMed Central

    Nakazato, Ryo; Berman, Daniel S.; Gransar, Heidi; Hyun, Mark; Miranda-Peats, Romalisa; Kite, Faith C.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Rozanski, Alan; Slomka, Piotr J.

    2012-01-01

    Background Most studies have reported using semi-quantitative analysis to assess the prognostic utility of SPECT myocardial perfusion imaging (MPI). Thus we studied the prognostic value of fully automated quantitative analysis software applied to new solid-state, high-speed (HS) SPECT-MPI. Methods 1613 consecutive patients undergoing exercise or adenosine HS-MPI were followed for 2.6±0.5 years for all-cause mortality (ACM). Automated quantitative software was used for assessing stress total perfusion deficit (sTPD) and was compared to semi-quantitative visual analysis. MPI was characterized as 0% (normal); 1–4% (minimal perfusion defect); 5–10% (mildly abnormal); and >10% (moderately/severely abnormal). Results During follow-up, 79 patients died (4.9%). Annualized ACM increased with progressively increasing sTPD; 0% (0.87%), 1–4% (1.94%), 5–10% (3.10%) and >10% (5.33%) (log-rank p<0.0001). While similar overall findings were observed with visual analysis, only sTPD demonstrated increased risk in patients with minimal perfusion defects. In multivariable analysis, sTPD >10% was a mortality predictor (HR 3.03, 95% CI 1.30–7.09, p=0.01). Adjusted mortality rate was substantial in adenosine MPI, but low in exercise MPI (9.0% versus 1.0%, p<0.0001). Conclusions By quantitative analysis, ACM increases with increasing perfusion abnormality among patients undergoing stress HS-MPI. These findings confirm previous results obtained with visual analysis using conventional Anger camera imaging systems. PMID:23065414

  14. Photoacoustic perfusion measurements: a comparison with power Doppler in phantoms

    NASA Astrophysics Data System (ADS)

    Heres, H. M.; Arabul, M. Ü.; Tchang, B. C.; van de Vosse, F. N.; Rutten, M. C.; Lopata, R. G.

    2015-03-01

    Ultrasound-based measurements using Doppler, contrast, and more recently photoacoustics (PA), have emerged as techniques for tissue perfusion measurements. In this study, the feasibility of in vitro perfusion measurements with a fully integrated, hand-held, photoacoustic probe was investigated and compared to Power Doppler (PD). Three cylindrical polyvinyl alcohol (PVA) phantoms were made (diameter = 15 mm) containing 100, 200 and 400 parallel polysulfone tubes (diameter = 0.2 mm), resulting in a perfused cross-sectional area of 1.8, 3.6 and 7.1% respectively. Each phantom was perfused with porcine blood (15 mL/min). Cross-sectional PA images (λ = 805nm, frame rate = 10Hz) and PD images (PRF = 750Hz) were acquired with a MyLab One and MyLab 70 scanner (Esaote, NL), respectively. Data were averaged over 70 frames. The average PA signal intensity was calculated in a region-of-interest of 4 mm by 6 mm. The percentage of colored PD pixels was measured in the entire phantom region. The average signal intensity of the PA images increased linearly with perfusion density, being 0.54 (+/- 0.01), 0.56 (+/- 0.01), 0.58 (+/- 0.01) with an average background signal of 0.53 in the three phantoms, respectively. For PD, the percentage of colored pixels in the phantom area (1.5% (+/- 0.2%), 4.4% (+/- 0.2%), 13.7% (+/- 0.8%)) also increased linearly. The preliminary results suggest that PA, like PD, is capable of detecting an increase of blood volume in tissue. In the future, in vivo measurements will be explored, although validation will be more complex.

  15. Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis.

    PubMed

    Bourke, S J; Hawkins, T; Keavey, P M; Gascoigne, A D; Corris, P A

    1993-06-01

    There is increasing interest in ventilation perfusion (V/Q) imaging in cryptogenic fibrosing alveolitis because of the data these scans provide on the dynamic V/Q relationships in such patients undergoing single lung transplantation. However, the full spectrum of V/Q abnormalities in this disease is poorly defined. We therefore analysed the V/Q scans of 45 consecutive patients with advanced cryptogenic fibrosing alveolitis being considered for single lung transplantation. Scans were classified according to the presence, severity and degree of matching of defects in ventilation and perfusion images and the results were compared with the data obtained from lung function tests. Ventilation images showed defects in 13 (29%) and 'washout delay' in 15 (33%) patients; 10 (22%) patients had asymmetric distribution of ventilation with one lung receiving > 60% of total ventilation. Perfusion images showed normal perfusion in 8 (18%), mild defects in 18 (40%) and major defects in 19 (42%) patients. The distribution of perfusion between lungs was significantly asymmetric in 20 (45%) patients. V/Q images were matched in 15 (33%), mildly mismatched in 15 (33%) and severely mismatched in 15 (33%) patients, but the degree of V/Q mismatch did not show a relationship to KCO, PaO2 or A-aO2 gradient. The appearances were atypical of pulmonary embolism in eight patients. V/Q images in cryptogenic fibrosing alveolitis show a diverse range of appearances and may mimic pulmonary embolism. V/Q imaging complements the data obtained from lung function tests and is particularly useful in defining the differential function of each lung which is particularly important in the assessment of patients for single lung transplantation. PMID:8321484

  16. Laser Doppler imaging of myocardial perfusion during coronary bypass surgery

    NASA Astrophysics Data System (ADS)

    Wardell, Karin; Hermansson, Ulf; Nilsson, Gert E.; Casimir-Ahn, Henrik

    2000-05-01

    Laser Doppler perfusion imaging has been used to assess the myocardium perfusion on the arrested heart during bypass surgery. Twenty-two patients undergoing coronary artery bypass grafting, including usage of the left internal thoracic artery, were included in the study. The anticipated perfusion increase following declamping of the internal thoracic artery was investigated by mapping areas at the size of 10 cm X 11 cm, (n equals 11) and 7 cm X 5 cm (n equals 11). The larger images allowed quantification of blood flow in different regions of the myocardium. The size of the affected area was 32.2 +/- 12.9 cm2 with a total increase of 3.17 +/- 0.75 a.u. (range 0 - 10 a.u.). Corresponding values for areas surrounding the vessels and areas defined as the larger vessels in the myocardium were 29.0 +/- 10.9 cm2 (2.85 +/- 0.57 a.u.) and 3.5 +/- 2.8 cm2 (6.78 +/- 0.18 a.u.). All subjects but two showed a substantial blood flow increase (> 2 a.u.) after release of the clamp. Six subjects had a total increase of at least 4 a.u. Correlation analysis between areas including various number of sites showed an r equals 0.91 (p < 0,0001) or better. In conclusion, laser Doppler perfusion imaging can easily be used intraoperatively in conjunction with bypass surgery. It enables immediate assessment of both the increase and spatial distribution of myocardial perfusion following declamping of an arterial graft.

  17. Vascular effects of acetylcholine in the perfused rabbit lung

    SciTech Connect

    Cherry, P.D.; Gillis, C.N.

    1986-03-05

    Acetylcholine (ACh) relaxes large, isolated arteries by releasing an endothelium-derived relaxing factor (EDRF). The authors decided to determine if ACh releases EDRF in rabbit lungs (RL) perfused in situ and if chemical injury with tetradecanoyl phorbol myristate acetate (TPA) could modify EDRF release in RL and in rabbit pulmonary arteries (RPA) in vitro. RL were perfused at 15 ml/min with Krebs-dextran solution. 1 ..mu..M ACh infusion raised perfusion pressure (P) in RL that was blocked by 30 ..mu..M indomethacin (IND) in the perfusate. However, when IND-treated RL were perfused with the stable endoperoxide analog, U46619 (2-6nM) to increase P, ACh infusion (0.01-1.0 ..mu..M) consistently decreased elevated P. The vasodilator response to infusion of 1 ..mu..M ACh was acutely antagonized by infusion of either 20 ..mu..M quinacrine (Q) or 10 ..mu..M Fe/sup + +/-hemoglobin (Hb). ACh did not decrease P in IND-treated RL pre-equilibrated with Q or Hb. TPA (10 nM) antagonized ACh-reduction of P and the ACh-induced relaxation of isolated RPA. The TPA antagonism of ACh-relaxation of RPA was prevented by catalase (300 U/ml). From these results they conclude that: 1) ACh-induced vasoconstriction in RL depends on cyclooxygenase product(s). 2) IND unmasks ACh-induced vasodilatation in RL that is inhibited by Q and by Hb suggesting that the effect is mediated by EDRF. 3) TPA inhibits ACh-induced vasodilatation and relaxation of RPA via the release of H/sub 2/O/sub 2/ or a related oxidant that injures the endothelium.

  18. Computed tomography perfusion imaging in spectacular shrinking deficit.

    PubMed

    Lee, Vivien H; John, Sayona; Mohammad, Yousef; Prabhakaran, Shyam

    2012-02-01

    Spectacular shrinking deficit (SSD) is characterized by abrupt onset of a major hemispheric stroke syndrome, followed by dramatic and rapid improvement. We retrospectively identified patients with SSD diagnosed at our institution between December 1, 2007, and June 30, 2009. We reviewed computed tomography perfusion (CTP) imaging to determine perfusion defect as a measure of initial ischemic penumbra, and magnetic resonance imaging diffusion-weighted imaging (DWI) to determine the final infarct core. Among the 472 consecutive ischemic stroke patients, 126 (27%) presented with major hemispheric ischemic stroke syndrome, defined as National Institutes of Health Stroke Scale score (NIHSS) ≥8 in the territory of the middle cerebral artery (MCA) or internal carotid artery (ICA). Out of these patients, we identified 8 SSD patients with available CTP data. In these 8 patients, the mean time to dramatic recovery was 3.4 hours (range, 0.75-7 hours), and the mean time from onset to CTP was 12.7 hours (range, 3-30 hours). All 8 patients had perfusion abnormalities in portions of the MCA territory (partial MCA territory in 5 patients and complete MCA territory in 3 patients). The mean time from onset to MRI DWI was 15.5 hours (range, 7.9-34 hours). Restricted diffusion was present in all patients in the corresponding MCA distribution. Vascular imaging revealed MCA occlusion in 2 patients. Cervical vascular imaging revealed carotid occlusion in 2 patients and high-grade carotid stenosis in 2 patients. The stroke mechanisms were cardioembolism in 2 patients, large artery in 4 patients, and unknown in 2 patients. Four patients had repeat CTP imaging available that demonstrated eventual resolution of the perfusion defect. SSD is associated with a "shrinking" clinical syndrome and a "shrinking" perfusion pattern on CTP that lags behind clinical recovery. CTP imaging corroborates that a larger territory is at risk in SSD and contributes to better understanding of SSD. PMID:20702113

  19. Cardiovascular responses to water immersion in humans: impact on cerebral perfusion

    PubMed Central

    Spence, Angela L.; Pugh, Christopher J. A.; Ainslie, Philip; Naylor, Louise H.; Green, Daniel J.

    2014-01-01

    Episodic increases in cerebrovascular perfusion and shear stress may have beneficial impacts on endothelial function that improve brain health. We hypothesized that water immersion to the level of the right atrium in humans would increase cerebral perfusion. We continuously measured, in 9 young (means ± SD, 24.6 ± 2.0 yr) healthy men, systemic hemodynamic variables along with blood flows in the common carotid and middle and posterior cerebral arteries during controlled filling and emptying of a water tank to the level of the right atrium. Mean arterial pressure (80 ± 9 vs. 91 ± 12 mmHg, P < 0.05), cardiac output (4.8 ± 0.7 vs. 5.1 ± 0.6 l/min, P < 0.05) and end-tidal carbon dioxide (PetCO2, 39.5 ± 2.0 vs. 44.4 ± 3.5 mmHg, P < 0.05) increased with water immersion, along with middle (59 ± 6 vs. 64 ± 6 cm/s, P < 0.05) and posterior cerebral artery blood flow velocities (41 ± 9 vs. 44 ± 10 cm/s, P < 0.05). These changes were reversed when the tank was emptied. Water immersion is associated with hemodynamic and PetCO2 changes, which increase cerebral blood velocities in humans. This study provides an evidence base for future studies to examine the potential additive effect of exercise in water on improving cerebrovascular health. PMID:24553298

  20. Altered Cerebral Perfusion in Executive, Affective, and Motor Networks During Adolescent Depression

    PubMed Central

    Ho, Tiffany C.; Wu, Jing; Shin, David D.; Liu, Thomas T.; Tapert, Susan F.; Yang, Guang; Connolly, Colm G.; Frank, Guido K.W.; Max, Jeffrey E.; Wolkowitz, Owen; Eisendrath, Stuart; Hoeft, Fumiko; Banerjee, Dipavo; Hood, Korey; Hendren, Robert L.; Paulus, Martin P.; Simmons, Alan N.; Yang, Tony T.

    2013-01-01

    Objective While substantial literature has reported regional cerebral blood flow (rCBF) abnormalities in adults with depression, these studies commonly necessitated the injection of radioisotopes into subjects. The recent development of arterial spin labeling (ASL), however, allows for noninvasive measurements of rCBF. Currently, no published ASL studies have examined cerebral perfusion in adolescents with depression. Thus, the aim of the present study was to examine baseline cerebral perfusion in adolescent depression using a newly developed ASL technique: pseudocontinuous arterial spin labeling (PCASL). Method 25 medication-naive adolescents (ages 13–17 years) diagnosed with major depressive disorder (MDD) and 26 well-matched controls underwent functional magnetic resonance imaging. Baseline rCBF was measured via a novel PCASL method that optimizes tagging efficiency. Results Voxel-based whole brain analyses revealed significant frontal, limbic, paralimbic, and cingulate hypoperfusion in the group with depression (p<0.05, corrected). Hyperperfusion was also observed within the subcallosal cingulate, putamen, and fusiform gyrus (p<0.05, corrected). Similarly, region-of-interest analyses revealed amygdalar and insular hypoperfusion in the group with depression, as well as hyperperfusion in the putamen and superior insula (p<0.05, corrected). Conclusions Adolescents with depression and healthy adolescents appear to differ on rCBF in executive, affective, and motor networks. Dysfunction in these regions may contribute to the cognitive, emotional, and psychomotor symptoms commonly present in adolescent depression. These findings point to possible biomarkers for adolescent depression that could inform early interventions and treatments and establishes a methodology for using PCASL to noninvasively measure rCBF in clinical and healthy adolescent populations. PMID:24074474

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

    PubMed

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

    2010-10-01

    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) (P < 0.01) and cardiac output by approximately 40% (P < 0.05), but did not affect mean arterial pressure. The central cardiovascular responses to exercise with glycopyrrolate were similar to the control responses, except that cardiac output did not increase during static handgrip with glycopyrrolate. Glycopyrrolate did not significantly affect cerebral metabolism during static handgrip, but a parallel increase in MCA V(mean) (approximately 16%; P < 0.01) and CBF (approximately 12%; P < 0.01) during static handgrip, as well as the increase in MCA V(mean) during cycling (approximately 15%; P < 0.01), were abolished by glycopyrrolate (P < 0.05). Thus, during both cycling and static handgrip, a cholinergic receptor mechanism is important for the exercise-induced increase in cerebral perfusion without affecting the cerebral metabolic rate for oxygen. PMID:20660020

  2. Comparison of lung preservation solutions in human lungs using an ex vivo lung perfusion experimental model

    PubMed Central

    Medeiros, Israel L.; Pêgo-Fernandes, Paulo M.; Mariani, Alessandro W.; Fernandes, Flávio G.; Unterpertinger, Fernando V.; Canzian, Mauro; Jatene, Fabio B.

    2012-01-01

    OBJECTIVE: Experimental studies on lung preservation have always been performed using animal models. We present ex vivo lung perfusion as a new model for the study of lung preservation. Using human lungs instead of animal models may bring the results of experimental studies closer to what could be expected in clinical practice. METHOD: Brain-dead donors whose lungs had been declined by transplantation teams were used. The cases were randomized into two groups. In Group 1, Perfadex® was used for pulmonary preservation, and in Group 2, LPDnac, a solution manufactured in Brazil, was used. An ex vivo lung perfusion system was used, and the lungs were ventilated and perfused after 10 hours of cold ischemia. The extent of ischemic-reperfusion injury was measured using functional and histological parameters. RESULTS: After reperfusion, the mean oxygenation capacity was 405.3 mmHg in Group 1 and 406.0 mmHg in Group 2 (p = 0.98). The mean pulmonary vascular resistance values were 697.6 and 378.3 dyn·s·cm-5, respectively (p = 0.035). The mean pulmonary compliance was 46.8 cm H2O in Group 1 and 49.3 ml/cm H2O in Group 2 (p = 0.816). The mean wet/dry weight ratios were 2.06 and 2.02, respectively (p = 0.87). The mean Lung Injury Scores for the biopsy performed after reperfusion were 4.37 and 4.37 in Groups 1 and 2, respectively (p = 1.0), and the apoptotic cell counts were 118.75/mm2 and 137.50/mm2, respectively (p = 0.71). CONCLUSION: The locally produced preservation solution proved to be as good as Perfadex®. The clinical use of LPDnac may reduce costs in our centers. Therefore, it is important to develop new models to study lung preservation. PMID:23018310

  3. Study on the cerebrovascular reserve capacity by MR perfusion weighted imaging in SHR

    NASA Astrophysics Data System (ADS)

    Zhou, Quan; Dong, Yang; Chen, WenLi; Lin, Xueying; Xing, Da; Huang, Li

    2007-05-01

    Cerebrovascular disease is one of the leading causes of death, and approximately 50% of survivors have a residual neurologic deficit and greater than 25% require chronic care. Cerebrovascular reserve capacity (CVRC) describes how far cerebral perfusion can increase from a baseline value after stimulation. High blood pressure is the most important independent risk factor for stroke and other vascular diseases. The incidence of stroke in the hypertensive is six times higher than in the patient with normal blood pressure. CVRC in the hypertensive was even lower than in control patients. MR perfusion weighted imaging (MR PWI) with the well-established acetazolamide (ACZ) stimulation test has been used for assessing brain function. The aim of this work is to assess the cerebrovascular reserve capacity by MR PWI with "ACZ" tolerance test in spontaneous hypertensive rat (SHR) and to identify its value in evaluating the CVRC. Experimental animal including 3 groups: Wistar-Kyoto rats (WKY) (12-week-old) as control group, SHR (12-week-old and 20-week-old) as experimental group. MR PWI was performed respectively before and after acetazolamide administrated orally in 3 groups on a clinical 1.5 Tesla GE Signa MR fx/i whole-body MR system. The ROI was chosen in the bilateral frontal lobe to measure the value of rCBV, rCBF and MTT. The results showed that before ACZ-test, there was statistic differences between the WKY and SHR(12-week-old), and between SHR(12-week-old) and SHR(20-week-old) in the values of rCBV and rCBF (P>0.05), and after ACZ-test, there were statistic differences between WKY and SHR (20-week-old), and between SHR(12-week-old) and SHR(20-week-old) in the rCBV value (P<0.05). It is concluded that the method of MRI PWI combined with the "ACZ stress test" can provide more qualitative and half-quantitative information on the cerebral perfusion to evaluate the CVRC in SHR.

  4. Steady-state first pass perfusion (SSFPP): A new approach to 3D first-pass myocardial perfusion imaging

    PubMed Central

    Giri, Shivraman; Xue, Hui; Maiseyeu, Andrei; Kroeker, Randall; Rajagopalan, Sanjay; White, Richard D.; Zuehlsdorff, Sven; Raman, Subha V.; Simonetti, Orlando P

    2013-01-01

    Purpose To describe and characterize a new approach to first-pass myocardial perfusion utilizing balanced steady-state free precession acquisition without the use of saturation recovery or other magnetization preparation. Theory The balanced steady-state free precession sequence is inherently sensitive to contrast agent enhancement of the myocardium. This sensitivity can be used to advantage in first-pass myocardial perfusion imaging by eliminating the need for magnetization preparation. Methods Bloch equation simulations, phantom experiments, and in vivo 2D imaging studies were run comparing the proposed technique with three other methods: saturation recovery spoiled gradient echo, saturation recovery steady-state free precession, and steady-state spoiled gradient echo without magnetization preparation. Additionally, an acquisition-reconstruction strategy for 3D perfusion imaging is proposed and initial experience with this approach is demonstrated in healthy subjects and one patient. Results Phantom experiments verified simulation results showing the sensitivity of the balanced steady-state free precession sequence to contrast agent enhancement in solid tissue is similar to that of magnetization-prepared acquisitions. Images acquired in normal volunteers showed the proposed technique provided superior signal and signal-to-noise ratio compared with all other sequences at baseline as well as post-contrast. Conclusion A new approach to first-pass myocardial perfusion is presented that obviates the need for magnetization preparation and provides high signal-to-noise ratio. PMID:23440705

  5. Venovenous perfusion in ECMO for newborn respiratory insufficiency. A clinical comparison with venoarterial perfusion.

    PubMed Central

    Klein, M D; Andrews, A F; Wesley, J R; Toomasian, J; Nixon, C; Roloff, D; Bartlett, R H

    1985-01-01

    Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been successful in the treatment of newborns less than 1 week of age and greater than 2000 gm birthweight with respiratory failure resistant to current medical and surgical management. While VA ECMO supports the heart as well as the lungs, it has the disadvantage of requiring carotid artery ligation and the possibility of perfusing air bubbles or particles into the arterial tree. We have treated 11 newborns with respiratory failure with venovenous (VV) ECMO returning the oxygenated blood to a cannula in the distal iliac vein. We compared these patients with 16 patients treated during the same period of time with VA ECMO. Three of the 11 VV patients required conversion to VA ECMO because of inadequate oxygenation and unstable hemodynamic situations. Ten of the 11 VV patients survived. Eleven of the 16 VA patients survived. The better survival in these patients treated with VV ECMO is attributed to their more favorable initial condition compared to patients treated with VA ECMO. The disadvantages of VV ECMO include a longer operative time to place the cannulas, groin wound problems, and persistent leg swelling along with the necessity to convert some patients to VA ECMO. Although this experience demonstrates that newborns with severe respiratory failure can be supported with VV ECMO, the complications and lack of practical advantages over VA lead us to recommend VA ECMO for routine clinical use at present. PMID:3977454

  6. Right Hemisphere Brain Damage

    MedlinePlus

    ... Language and Swallowing / Disorders and Diseases Right Hemisphere Brain Damage [ en Español ] What is right hemisphere brain ... right hemisphere brain damage ? What is right hemisphere brain damage? Right hemisphere brain damage (RHD) is damage ...

  7. Brain tumor - primary - adults

    MedlinePlus

    ... Vestibular schwannoma (acoustic neuroma) - adults; Meningioma - adults; Cancer - brain tumor (adults) ... Primary brain tumors include any tumor that starts in the brain. Primary brain tumors can start from brain cells, ...

  8. Brain radiation - discharge

    MedlinePlus

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  9. Thyrotropin-releasing hormone metabolism and extraction by the perfused guinea pig placenta

    SciTech Connect

    Nogimori, T.; Alex, S.; Baker, S.; Emerson, C.H.

    1985-08-01

    This report describes the extraction of synthetic TRH and its metabolic conversion in the perfused guinea pig placenta. These studies were performed to obtain an estimate of fractional fetal TRH losses through the placenta and to determine if some of these losses are due to TRH metabolism. Experiments were performed in which the perfusion buffer contained 0.01, 1, and 10 micrograms/ml or no synthetic TRH. In experiments in which TRH was perfused, the perfusion reservoir contents and placental effluent fractions were counted for TH, and TRH and deamido-TRH were determined by RIA. Similarly, cyclo(His-Pro) was measured when 10 micrograms/ml TRH were perfused. When synthetic TRH was perfused, steady state TRH concentrations were achieved in placental effluent fractions by 20-30 min. The single pass extraction of TRH by the placenta was 11.4 +/- 2.6% (mean +/- SE) compared to 56.9 +/- 7.0% for TH22O. No significant difference was detected regardless of whether 10, 1, or 0.01 micrograms/ml TRH were perfused. A portion of the TRH that perfused the placenta was converted to deamido-TRH at all concentrations of perfused TRH. The conversion of TRH to TRH-OH was 4.2 +/- 0.7% in a single pass. When the perfusion buffer was devoid of synthetic TRH, a small but significant increase in the content of TRH immunoreactivity was noted in the placental effluent compared to that in the perfusion reservoir.

  10. Noninvasive Blood Perfusion Measurements of an Isolated Rat Liver and an Anesthetized Rat Kidney

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Lee, Charles Y.; Diller, Thomas E.; Scott, Elaine P.

    2008-01-01

    A simple, cost effective, and noninvasive blood perfusion system is tested in animal models. The system uses a small sensor to measure the heat transfer response to a thermal event (convective cooling) imposed on the tissue surface. Heat flux data are compared with a mathematical model of the tissue to estimate both blood perfusion and thermal contact resistance between the tissue and the probe. The perfusion system was evaluated for repeatability and sensitivity using isolated rat liver and exposed rat kidney tests. Perfusion in the isolated liver tests was varied by controlling the flow of the perfusate into the liver, and the perfusion in the exposed kidney tests was varied by temporarily occluding blood flow through the renal artery and vein. The perfusion estimated by the convective perfusion probe was in good agreement with that of the metered flow of the perfusate into the liver model. The liver tests indicated that the probe can be used to detect small changes in perfusion (0.005 ml/ml/s). The probe qualitatively tracked the changes in the perfusion in the kidney model due to occlusion of the renal artery and vein. PMID:19045542

  11. Development of an Extracorporeal Perfusion Device for Small Animal Free Flaps

    PubMed Central

    Fichter, Andreas M.; Ritschl, Lucas M.; Borgmann, Anna; Humbs, Martin; Luppa, Peter B.; Wolff, Klaus-Dietrich; Mücke, Thomas

    2016-01-01

    Background Extracorporeal perfusion (ECP) might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps. Methods After establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood) were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7. Results ECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27%) was even lower than after in vivo perfusion (49%), although not statistically significant (P = 0,083). After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%). Angiographic and histological findings confirmed these observations. Conclusions Vital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies. PMID:26808996

  12. Brain Development

    MedlinePlus

    ... new neural connections every second. This growing brain development is influenced by many factors, including a child’s relationships, experiences and environment. Learn more about the crucial role you play ...

  13. Brain herniation

    MedlinePlus

    Ling GSF. Traumatic brain injury and spinal cord injury. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 406. Stippler M. Trauma of ...

  14. A Short Period of Ventilation without Perfusion Seems to Reduce Atelectasis without Harming the Lungs during Ex Vivo Lung Perfusion

    PubMed Central

    Pierre, Leif

    2013-01-01

    To evaluate the lung function of donors after circulatory deaths (DCDs), ex vivo lung perfusion (EVLP) has been shown to be a valuable method. We present modified EVLP where lung atelectasis is removed, while the lung perfusion is temporarily shut down. Twelve pigs were randomized into two groups: modified EVLP and conventional EVLP. When the lungs had reached 37°C in the EVLP circuit, lung perfusion was temporarily shut down in the modified EVLP group, and positive end-expiratory pressure (PEEP) was increased to 10 cm H2O for 10 minutes. In the conventional EVLP group, PEEP was increased to 10 cm H2O for 10 minutes with unchanged lung perfusion. In the modified EVLP group, the arterial oxygen partial pressure (PaO2) was 18.5 ± 7.0 kPa before and 64.5 ± 6.0 kPa after the maneuver (P < 0.001). In the conventional EVLP group, the PaO2 was 16.8 ± 3.1 kPa and 46.8 ± 2.7 kPa after the maneuver (P < 0.01; P < 0.01). In the modified EVLP group, the pulmonary graft weight was unchanged, while in the conventional EVLP group, the pulmonary graft weight was significantly increased. Modified EVLP with normoventilation of the lungs without ongoing lung perfusion for 10 minutes may eliminate atelectasis almost completely without harming the lungs. PMID:24102021

  15. A Short Period of Ventilation without Perfusion Seems to Reduce Atelectasis without Harming the Lungs during Ex Vivo Lung Perfusion.

    PubMed

    Lindstedt, Sandra; Pierre, Leif; Ingemansson, Richard

    2013-01-01

    To evaluate the lung function of donors after circulatory deaths (DCDs), ex vivo lung perfusion (EVLP) has been shown to be a valuable method. We present modified EVLP where lung atelectasis is removed, while the lung perfusion is temporarily shut down. Twelve pigs were randomized into two groups: modified EVLP and conventional EVLP. When the lungs had reached 37°C in the EVLP circuit, lung perfusion was temporarily shut down in the modified EVLP group, and positive end-expiratory pressure (PEEP) was increased to 10 cm H2O for 10 minutes. In the conventional EVLP group, PEEP was increased to 10 cm H2O for 10 minutes with unchanged lung perfusion. In the modified EVLP group, the arterial oxygen partial pressure (PaO2) was 18.5 ± 7.0 kPa before and 64.5 ± 6.0 kPa after the maneuver (P < 0.001). In the conventional EVLP group, the PaO2 was 16.8 ± 3.1 kPa and 46.8 ± 2.7 kPa after the maneuver (P < 0.01; P < 0.01). In the modified EVLP group, the pulmonary graft weight was unchanged, while in the conventional EVLP group, the pulmonary graft weight was significantly increased. Modified EVLP with normoventilation of the lungs without ongoing lung perfusion for 10 minutes may eliminate atelectasis almost completely without harming the lungs. PMID:24102021

  16. Uptake of ANG1005, a Novel Paclitaxel Derivative, Through the Blood-Brain Barrier into Brain and Experimental Brain Metastases of Breast Cancer

    PubMed Central

    Thomas, Fancy C.; Taskar, Kunal; Rudraraju, Vinay; Goda, Satyanarayana; Thorsheim, Helen R.; Gaasch, Julie A.; Palmieri, Diane; Steeg, Patricia S.; Lockman, Paul R.; Smith, Quentin R.

    2010-01-01

    Purpose We evaluated the uptake of angiopep-2 paclitaxel conjugate, ANG1005, into brain and brain metastases of breast cancer in rodents. Most anticancer drugs show poor delivery to brain tumors due to limited transport across the blood-brain barrier (BBB). To overcome this, a 19-amino acid peptide (angiopep-2) was developed that binds to low density lipoprotein receptor-related protein (LRP) receptors at the BBB and has the potential to deliver drugs to brain by receptor-mediated transport. Methods The transfer coefficient (Kin) for brain influx was measured by in situ rat brain perfusion. Drug distribution was determined at 30 min after i.v. injection in mice bearing intracerebral MDA-MB-231BR metastases of breast cancer. Results The BBB Kin for 125I-ANG1005 uptake (7.3 ± 0.2 × 10−3 mL/s/g) exceeded that for 3H-paclitaxel (8.5 ± 0.5 × 10−5) by 86 fold. Over 70% of 125I-ANG1005 tracer stayed in brain after capillary depletion or vascular washout. Brain 125I-ANG1005 uptake was reduced by unlabeled angiopep-2 vector and by LRP ligands, consistent with receptor transport. In vivo uptake of 125I-ANG1005 into vascularly corrected brain and brain metastases exceeded that of 14C-paclitaxel by 4–54 fold. Conclusions The results demonstrate that ANG1005 shows significantly improved delivery to brain and brain metastases of breast cancer compared to free paclitaxel. PMID:19774344

  17. Brain imaging and brain function

    SciTech Connect

    Sokoloff, L.

    1985-01-01

    This book is a survey of the applications of imaging studies of regional cerebral blood flow and metabolism to the investigation of neurological and psychiatric disorders. Contributors review imaging techniques and strategies for measuring regional cerebral blood flow and metabolism, for mapping functional neural systems, and for imaging normal brain functions. They then examine the applications of brain imaging techniques to the study of such neurological and psychiatric disorders as: cerebral ischemia; convulsive disorders; cerebral tumors; Huntington's disease; Alzheimer's disease; depression and other mood disorders. A state-of-the-art report on magnetic resonance imaging of the brain and central nervous system rounds out the book's coverage.

  18. Contrast-Enhanced Ultrasound Imaging for the Detection of Focused Ultrasound-Induced Blood-Brain Barrier Opening

    PubMed Central

    Fan, Ching-Hsiang; Lin, Wun-Hao; Ting, Chien-Yu; Chai, Wen-Yen; Yen, Tzu-Chen; Liu, Hao-Li; Yeh, Chih-Kuang

    2014-01-01

    The blood-brain barrier (BBB) can be transiently and locally opened by focused ultrasound (FUS) in the presence of microbubbles (MBs). Various imaging modalities and contrast agents have been used to monitor this process. Unfortunately, direct ultrasound imaging of BBB opening with MBs as contrast agent is not feasible, due to the inability of MBs to penetrate brain parenchyma. However, FUS-induced BBB opening is accompanied by changes in blood flow and perfusion, suggesting the possibility of perfusion-based ultrasound imaging. Here we evaluated the use of MB destruction-replenishment, which was originally developed for analysis of ultrasound perfusion kinetics, for verifying and quantifying FUS-induced BBB opening. MBs were intravenously injected and the BBB was disrupted by 2 MHz FUS with burst-tone exposure at 0.5-0.7 MPa. A perfusion kinetic map was estimated by MB destruction-replenishment time-intensity curve analysis. Our results showed that the scale and distribution of FUS-induced BBB opening could be determined at high resolution by ultrasound perfusion kinetic analysis. The accuracy and sensitivity of this approach was validated by dynamic contrast-enhanced MRI. Our successful demonstration of ultrasound imaging to monitor FUS-induced BBB opening provides a new approach to assess FUS-dependent brain drug delivery, with the benefit of high temporal resolution and convenient integration with the FUS device. PMID:25161701

  19. Culturing thick brain slices: An interstitial 3D microperfusion system for enhanced viability

    PubMed Central

    Rambani, Komal; Vukasinovic, Jelena; Glezer, Ari; Potter, Steve M.

    2009-01-01

    Brain slice preparations are well-established models for a wide spectrum of in vitro investigations in the neuroscience discipline. However, these investigations are limited to acute preparations or thin organotypic culture preparations due to the lack of a successful method that allows culturing of thick organotypic brain slices. Thick brain slice cultures suffer necrosis due to ischemia deep in the tissue resulting from a destroyed circulatory system and subsequent diffusion-limited supply of nutrients and oxygen. Although thin organotypic brain slice cultures can be successfully cultured using a well established roller tube method (a monolayer organotypic culture) (Gahwiler B H, 1981) or a membrane insert method (up to 1–4 cell layers, <150μm)(Stoppini L et al., 1991), these methods fail to support thick tissue preparations. A few perfusion methods (using submerged or interface/microfluidic chambers) have been reported to enhance the longevity (up to few hours) of acute slice preparations (up to 600μm thick) (Hass H L et al., 1979; Nicoll R A and Alger B E, 1981; Passeraub P A et al., 2003). Here, we report a unique interstitial microfluidic perfusion technique to culture thick (700μm) organotypic brain slices. The design of the custom-made micro-perfusion chamber facilitates laminar, interstitial perfusion of oxygenated nutrient medium throughout the tissue thickness with concomitant removal of depleted medium and catabolites. We examined the utility of this perfusion method to enhance the viability of the thick organotypic brain slice cultures after 2 days and 5 days in vitro (DIV). We investigated the range of amenable flow rates that enhance the viability of 700μm thick organotypic brain slices compared to the unperfused control cultures. Our perfusion method allows up to 84.6% viability (P<0.01) and up to 700μm thickness, even after 5 DIV. Our results also confirm that these cultures are functionally active and have their in vivo cytoarchitecture

  20. Measurement of steroid concentrations in brain tissue: methodological considerations.

    PubMed

    Taves, Matthew D; Ma, Chunqi; Heimovics, Sarah A; Saldanha, Colin J; Soma, Kiran K

    2011-01-01

    It is well recognized that steroids are synthesized de novo in the brain (neurosteroids). In addition, steroids circulating in the blood enter the brain. Steroids play numerous roles in the brain, such as influencing neural development, adult neuroplasticity, behavior, neuroinflammation, and neurodegenerative diseases such as Alzheimer's disease. In order to understand the regulation and functions of steroids in the brain, it is important to directly measure steroid concentrations in brain tissue. In this brief review, we discuss methods for the detection and quantification of steroids in the brain. We concisely present the major advantages and disadvantages of different technical approaches at various experimental stages: euthanasia, tissue collection, steroid extraction, steroid separation, and steroid measurement. We discuss, among other topics, the potential effects of anesthesia and saline perfusion prior to tissue collection; microdissection via Palkovits punch; solid phase extraction; chromatographic separation of steroids; and immunoassays and mass spectrometry for steroid quantification, particularly the use of mass spectrometry for "steroid profiling." Finally, we discuss the interpretation of local steroid concentrations, such as comparing steroid levels in brain tissue with those in the circulation (plasma vs. whole blood samples; total vs. free steroid levels). We also present reference values for a variety of steroids in different brain regions of adult rats. This brief review highlights some of the major methodological considerations at multiple experimental stages and provides a broad framework for designing studies that examine local steroid levels in the brain as well as other steroidogenic tissues, such as thymus, breast, and prostate. PMID:22654806

  1. Brain death.

    PubMed

    Wijdicks, Eelco F M

    2013-01-01

    The diagnosis of brain death should be based on a simple premise. If every possible confounder has been excluded and all possible treatments have been tried or considered, irreversible loss of brain function is clinically recognized as the absence of brainstem reflexes, verified apnea, loss of vascular tone, invariant heart rate, and, eventually, cardiac standstill. This condition cannot be reversed - not even partly - by medical or surgical intervention, and thus is final. Many countries in the world have introduced laws that acknowledge that a patient can be declared brain-dead by neurologic standards. The U.S. law differs substantially from all other brain death legislation in the world because the U.S. law does not spell out details of the neurologic examination. Evidence-based practice guidelines serve as a standard. In this chapter, I discuss the history of development of the criteria, the current clinical examination, and some of the ethical and legal issues that have emerged. Generally, the concept of brain death has been accepted by all major religions. But patients' families may have different ideas and are mostly influenced by cultural attitudes, traditional customs, and personal beliefs. Suggestions are offered to support these families. PMID:24182378

  2. [Continuous perfusion culture hybridoma cells for production of monoclonal antibody].

    PubMed

    Mi, Li; Li, Ling; Feng, Qiang; Yu, Xiao-Ling; Chen, Zhi-Nan

    2002-05-01

    Hybridoma cells were cultured by continuous perfusion in Fibra-Cel of 5L packed-bed bioreactor for 22 days in low serum or serum-free media. The corresponded amino acids were fed and serum concentration was decreased by analyzing glucose concentration, oxygen uptake rate, secretary antibody amount and amino acids concentration in culture supernatant. Comparing with continuous perfusion culture that amino acids were not fed, antibody amount of production was increased about 2-3 times. The inoculated cell density was 2.5 x 10(5) cells/mL, while the final cell density was 8.79 x 10(8) cells/mL. Antibody production was reached 295 mg/L/d at average level, and the highest level was reached 532 mg/L/d. These results provided a primary mode of enlarge culture for monoclonal antibody industralization. PMID:12192875

  3. The role of perfusion bioreactors in bone tissue engineering

    PubMed Central

    Gaspar, Diana Alves; Gomide, Viviane; Monteiro, Fernando Jorge

    2012-01-01

    Tissue engineering has emerged as a possible alternative to current treatments for bone injuries and defects. However, the common tissue engineering approach presents some obstacles to the development of functional tissues, such as insufficient nutrient and metabolite transport and non-homogenous cell distribution. Culture of bone cells in three-dimensional constructs in bioreactor systems is a solution for those problems as it improves mass transport in the culture system. For bone tissue engineering spinner flasks, rotating wall vessels and perfusion systems have been investigated, and based on these, variations that support cell seeding and mechanical stimulation have also been researched. This review aims at providing an overview of the concepts, advantages and future applications of bioreactor systems for bone tissue engineering with emphasis on the design of different perfusion systems and parameters that can be optimized. PMID:23507883

  4. Myocardial perfusion abnormalities in asymptomatic patients with systemic lupus erythematosus

    SciTech Connect

    Hosenpud, J.D.; Montanaro, A.; Hart, M.V.; Haines, J.E.; Specht, H.D.; Bennett, R.M.; Kloster, F.E.

    1984-08-01

    Accelerated coronary artery disease and myocardial infarction in young patients with systemic lupus erythematosus is well documented; however, the prevalence of coronary involvement is unknown. Accordingly, 26 patients with systemic lupus were selected irrespective of previous cardiac history to undergo exercise thallium-201 cardiac scintigraphy. Segmental perfusion abnormalities were present in 10 of the 26 studies (38.5 percent). Five patients had reversible defects suggesting ischemia, four patients had persistent defects consistent with scar, and one patient had both reversible and persistent defects in two areas. There was no correlation between positive thallium results and duration of disease, amount of corticosteroid treatment, major organ system involvement or age. Only a history of pericarditis appeared to be associated with positive thallium-201 results (p less than 0.05). It is concluded that segmental myocardial perfusion abnormalities are common in patients with systemic lupus erythematosus. Whether this reflects large-vessel coronary disease or small-vessel abnormalities remains to be determined.

  5. Experimental intraocular malignancy: the effect of intracameral perfusion.

    PubMed Central

    Wong, V G; Green, W R; Liu, Y P; Marsden, E R

    1979-01-01

    Transplantable Brown-Pearce carcinoma was adapted successfully in the rabbit anterior chamber. Regression of tumor growth was attained on tri-weekly perfusion of the AC with 10 micromolar of methotrexate. Tumor cyclic nucleotide phosphodiesterase (PDE) and protein activator were found to be markedly depressed during the course of chemotherapy and the PDE cAMP/cGMP ratio was similarly altered. Corroborative light and electron-microscopic studies showed specific alterations of intracellular organelles in relation to MTX and tumor cell death. These findings suggest that metabolic pathways of cyclic nucleotides are important biochemical modulators of neoplastic cells. The method of intraocular perfusion precludes systemic toxic effects and avoids compromising the animals' immunocompetence. Images FIGURE 3 A FIGURE 3 B FIGURE 4 A FIGURE 4 B PMID:232585

  6. Myocardial perfusion imaging for detection of silent myocardial ischemia

    SciTech Connect

    Beller, G.A.

    1988-04-21

    Despite the widespread use of the exercise stress test in diagnosing asymptomatic myocardial ischemia, exercise radionuclide imaging remains useful for detecting silent ischemia in numerous patient populations, including those who are totally asymptomatic, those who have chronic stable angina, those who have recovered from an episode of unstable angina or an uncomplicated myocardial infarction, and those who have undergone angioplasty or received thrombolytic therapy. Studies show that thallium scintigraphy is more sensitive than exercise electrocardiography in detecting ischemia, i.e., in part, because perfusion defects occur more frequently than ST depression and before angina in the ischemic cascade. Thallium-201 scintigraphy can be performed to differentiate a true- from a false-positive exercise electrocardiographic test in patients with exercise-induced ST depression and no angina. The development of technetium-labeled isonitriles may improve the accuracy of myocardial perfusion imaging. 11 references.

  7. Scalable Approach for Extrusion and Perfusion of Tubular, Heterotypic Biomaterials

    NASA Astrophysics Data System (ADS)

    Jeronimo, Mark David

    Soft material tubes are critical in the vasculature of mammalian tissues, forming networks of blood vessels and airways. Homogeneous and heterogeneous hydrogel tubes were extruded in a one-step process using a three layer microfluidic device. Co-axial cylindrical flow of crosslinking solutions and an alginate matrix is generated by a radial arrangement of microfluidic channels at the device's vertical extrusion outlet. The flow is confined and begins a sol-gel transition immediately as it extrudes at velocities upwards of 4 mm/s. This approach allows for predictive control over the dimensions of the rapidly formed tubular structures for outer diameters from 600 microm to 3 mm. A second microfluidic device hosts tube segments for controlled perfusion and pressurization using a reversible vacuum seal. On-chip tube deflection is observed and modeled as a measure of material compliance and circumferential elasticity. I anticipate applications of these devices for perfusion cell culture of cell-laden hydrogel tubes.

  8. Cardiac PET Perfusion: Prognosis, Risk Stratification, Clinical Management

    PubMed Central

    Dorbala, Sharmila; Di Carli, Marcelo F.

    2014-01-01

    Myocardial perfusion imaging (MPI) with positron emission tomography (PET) has expanded significantly over the past decade. With the wider availability of PET scanners and the routine use of quantitative blood flow imaging, the clinical use of PET MPI is expected to increase further. PET MPI is a powerful tool to identify risk, to quantify risk, and to guide therapy in patients with known or suspected coronary artery disease (CAD). A large body of evidence supports the prognostic value of PET MPI and ejection fraction in intermediate to high risk subjects, in women, in obese individuals and in post coronary artery bypass grafting (CABG) individuals. A normal perfusion study indicates low risk (< 1% annualized rate of cardiac events of cardiac death and non-fatal myocardial infarction), while an abnormal study indicates high risk. With accurate risk stratification, high quality images, and quantitation PET MPI may transform the management of patients with known or suspected CAD. PMID:25234079

  9. "Matching" ventilation/perfusion images in fat embolization.

    PubMed

    Skarzynski, J J; Slavin, J D; Spencer, R P; Karimeddini, M K

    1986-01-01

    Forty-eight hours after fracture of the tibia and fibula, a 27-year-old man developed the triad of findings noted in the fat embolism syndrome (neurologic changes, respiratory distress, and petechiae). An initially normal chest-x-ray, which progressed to one of bilateral fluffy diffuse infiltrates, aided in making the diagnosis. Ventilation/perfusion lung images were performed at the time of the radiographic changes and showed "matching" defects. Transcapillary passage of lipid breakdown products was considered to be the cause. While all parts of the lung showed reduced ventilation/perfusion, the upper half of the lung fields was affected more prominently, as opposed to emboli of venous origin, which most frequently involve the lung bases. PMID:3943243

  10. Topographic distribution of pulmonary ventilation and perfusion in the horse

    SciTech Connect

    Amis, T.C.; Pascoe, J.R.; Hornof, W.

    1984-08-01

    The regional distribution of ventilation to perfusion ratios (VA/Q) in the lungs of 8 healthy standing Thoroughbred geldings (4.4 +/- 1.5 years, 465.7 +/- 46.6 kg) was studied, using steady-state inhalation and IV infusion of the radioactive gas krypton-81m. The VA/Q was uniformly distributed within a vertical lung strip centered over the 9th rib on the right side. Ventilation per unit of alveolar volume (V/VA) assessed from the clearance of inhaled radioactive gas in 5 horses increased from 0.49 +/- 0.13 (arbitrary units) in nondependent lung zones to 1.45 +/- 0.16 in dependent lung zones. Seemingly, a vertical gradient of pulmonary ventilation exists in the horse that is matched by a similar gradient of perfusion.

  11. Photoplethysmographic sensors for perfusion measurements in spinal cord tissue

    NASA Astrophysics Data System (ADS)

    Phillips, J. P.; Kyriacou, P. A.

    2011-08-01

    Sensors for recording photoplethysmographic signals from the nervous tissue of the spinal cord are described. The purpose of these sensors is to establish whether perfusion is compromised in various states of injury which occur in certain animal models of spinal cord injury, for example compression injury. Various measures of perfusion are applicable such as the amplitude of the photoplethysmograph signal and the oxygen saturation, measured using a dual wavelength configuration. Signals are usually compared to baseline measurements made in uninjured subjects. This paper describes two types of probe, one based on optical fibres, and one in which optotes are placed in direct contact with the tissue surface. Results from a study based on a compression model utilising a fibreoptic sensor are presented.

  12. Non-Ischemic Perfusion Defects due to Delayed Arrival of Contrast Material on Stress Perfusion Cardiac Magnetic Resonance Imaging after Coronary Artery Bypass Graft Surgery

    PubMed Central

    Kim, Yeo Koon; Park, Sang Joon; Cheon, Gi Jeong; Lee, Whal; Chung, Jin Wook; Park, Jae Hyung

    2014-01-01

    Herein we report about the adenosine stress perfusion MR imaging findings of a 50-year-old man who exhibited two different perfusion defects resulting from two different mechanisms after a coronary artery bypass surgery. An invasive coronary angiography confirmed that one perfusion defect at the mid-anterior wall resulted from an ischemia due to graft stenosis. However, no stenosis was detected on the graft responsible for the mid-inferior wall showing the other perfusion defect. It was assumed that the perfusion defect at the mid-inferior wall resulted from delayed perfusion owing to the long pathway of the bypass graft. The semiquantitative analysis of corrected signal-time curves supported our speculation, demonstrating that the rest-to-stress ratio index of the maximal slope of the myocardial territory in question was similar to those of normal myocardium, whereas that of myocardium with the stenotic graft showed a typical ischemic pattern. A delayed perfusion during long graft pathway in a post-bypass graft patient can mimick a true perfusion defect on myocardial stress MR imaging. Radiologists should be aware of this knowledge to avoid misinterpretation of graft and myocardial status in post bypass surgery patients. PMID:24644408

  13. Myocardial Perfusion and Function Are Distinctly Altered by Sevoflurane Anesthesia in Diet-Induced Prediabetic Rats.

    PubMed

    van den Brom, Charissa E; Boly, Chantal A; Bulte, Carolien S E; van den Akker, Rob F P; Kwekkeboom, Rick F J; Loer, Stephan A; Boer, Christa; Bouwman, R Arthur

    2016-01-01

    Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial perfusion and function in prediabetic rats. Rats were fed a western diet (WD; n = 18) or control diet (CD; n = 18) for 8 weeks and underwent (contrast) echocardiography to determine perfusion and function during baseline and sevoflurane exposure. Myocardial perfusion was estimated based on the product of microvascular filling velocity and blood volume. WD-feeding resulted in a prediabetic phenotype characterized by obesity, hyperinsulinemia, hyperlipidemia, glucose intolerance, and hyperglycemia. At baseline, WD-feeding impaired myocardial perfusion and systolic function compared to CD-feeding. Exposure of healthy rats to sevoflurane increased the microvascular filling velocity without altering myocardial perfusion but impaired systolic function. In prediabetic rats, sevoflurane did also not affect myocardial perfusion; however, it further impaired systolic function. Diet-induced prediabetes is associated with impaired myocardial perfusion and function in rats. While sevoflurane further impaired systolic function, it did not affect myocardial perfusion in prediabetic rats. Our findings suggest that sevoflurane anesthesia leads to uncoupling of myocardial perfusion and function, irrespective of the metabolic state. PMID:26824042

  14. Myocardial Perfusion and Function Are Distinctly Altered by Sevoflurane Anesthesia in Diet-Induced Prediabetic Rats

    PubMed Central

    van den Brom, Charissa E.; Boly, Chantal A.; Bulte, Carolien S. E.; van den Akker, Rob F. P.; Kwekkeboom, Rick F. J.; Loer, Stephan A.; Boer, Christa; Bouwman, R. Arthur

    2016-01-01

    Preservation of myocardial perfusion during surgery is particularly important in patients with increased risk for perioperative complications, such as diabetes. Volatile anesthetics, like sevoflurane, have cardiodepressive effects and may aggravate cardiovascular complications. We investigated the effect of sevoflurane on myocardial perfusion and function in prediabetic rats. Rats were fed a western diet (WD; n = 18) or control diet (CD; n = 18) for 8 weeks and underwent (contrast) echocardiography to determine perfusion and function during baseline and sevoflurane exposure. Myocardial perfusion was estimated based on the product of microvascular filling velocity and blood volume. WD-feeding resulted in a prediabetic phenotype characterized by obesity, hyperinsulinemia, hyperlipidemia, glucose intolerance, and hyperglycemia. At baseline, WD-feeding impaired myocardial perfusion and systolic function compared to CD-feeding. Exposure of healthy rats to sevoflurane increased the microvascular filling velocity without altering myocardial perfusion but impaired systolic function. In prediabetic rats, sevoflurane did also not affect myocardial perfusion; however, it further impaired systolic function. Diet-induced prediabetes is associated with impaired myocardial perfusion and function in rats. While sevoflurane further impaired systolic function, it did not affect myocardial perfusion in prediabetic rats. Our findings suggest that sevoflurane anesthesia leads to uncoupling of myocardial perfusion and function, irrespective of the metabolic state. PMID:26824042

  15. Reflectance Photoplethysmography as Noninvasive Monitoring of Tissue Blood Perfusion.

    PubMed

    Abay, Tomas Ysehak; Kyriacou, Panayiotis A

    2015-09-01

    In the last decades, photoplethysmography (PPG) has been used as a noninvasive technique for monitoring arterial oxygen saturation by pulse oximetry (PO), whereas near-infrared spectroscopy (NIRS) has been employed for monitoring tissue blood perfusion. While NIRS offers more parameters to evaluate oxygen delivery and consumption in deep tissues, PO only assesses the state of oxygen delivery. For a broader assessment of blood perfusion, this paper explores the utilization of dual-wavelength PPG by using the pulsatile (ac) and continuous (dc) PPG for the estimation of arterial oxygen saturation (SpO2) by conventional PO. Additionally, the Beer-Lambert law is applied to the dc components only for the estimation of changes in deoxyhemoglobin (HHb), oxyhemoglobin (HbO2), and total hemoglobin (tHb) as in NIRS. The system was evaluated on the forearm of 21 healthy volunteers during induction of venous occlusion (VO) and total occlusion (TO). A reflectance PPG probe and NIRS sensor were applied above the brachioradialis, PO sensors were applied on the fingers, and all the signals were acquired simultaneously. While NIRS and forearm SpO2 indicated VO, SpO2 from the finger did not exhibit any significant drop from baseline. During TO, all the indexes indicated the change in blood perfusion. HHb, HbO2, and tHb changes estimated by PPG presented high correlation with the same parameters obtained by NIRS during VO (r(2) = 0.960, r(2) = 0.821, and r(2) = 0.974, respectively) and during TO (r(2) = 0.988, r(2) = 0.940, and r(2) = 0.938, respectively). The system demonstrated the ability to extract valuable information from PPG signals for a broader assessment of tissue blood perfusion. PMID:25838515

  16. Cardiac PET perfusion tracers: current status and future directions.

    PubMed

    Maddahi, Jamshid; Packard, René R S

    2014-09-01

    PET myocardial perfusion imaging (MPI) is increasingly being used for noninvasive detection and evaluation of coronary artery disease. However, the widespread use of PET MPI has been limited by the shortcomings of the current PET perfusion tracers. The availability of these tracers is limited by the need for an onsite ((15)O water and (13)N ammonia) or nearby ((13)N ammonia) cyclotron or commitment to costly generators ((82)Rb). Owing to the short half-lives, such as 76 seconds for (82)Rb, 2.06 minutes for (15)O water, and 9.96 minutes for (13)N ammonia, their use in conjunction with treadmill exercise stress testing is either not possible ((82)Rb and (15)O water) or not practical ((13)N ammonia). Furthermore, the long positron range of (82)Rb makes image resolution suboptimal and its low myocardial extraction limits its defect resolution. In recent years, development of an (18)F-labeled PET perfusion tracer has gathered considerable interest. The longer half-life of (18)F (109 minutes) would make the tracer available as a unit dose from regional cyclotrons and allow use in conjunction with treadmill exercise testing. Furthermore, the short positron range of (18)F would result in better image resolution. Flurpiridaz F 18 is by far the most thoroughly studied in animal models and is the only (18)F-based PET MPI radiotracer currently undergoing clinical evaluation. Preclinical and clinical experience with Flurpiridaz F 18 demonstrated a high myocardial extraction fraction, high image and defect resolution, high myocardial uptake, slow myocardial clearance, and high myocardial-to-background contrast that was stable over time-important properties of an ideal PET MPI radiotracer. Preclinical data from other (18)F-labeled myocardial perfusion tracers are encouraging. PMID:25234078

  17. Perfusion lung scan: an aid in detection of lymphangitic carcinomatosis

    SciTech Connect

    Bates, S.E.; Tranum, B.L.

    1982-07-15

    Lymphangitic carcinomatosis is usually a late manifestation of metastatic disease. The patient usually presents with cough or dyspnea, and the chest radiograph is often nondiagnostic. Two patients are presented who developed symptoms while on adjuvant chemotherapy. Both had abnormal perfusion lung scans. One had matching ventilation defects; the other a normal ventilation study. Biopsy revealed metastatic carcinoma; in one case tumor was seen in both the pulmonary lymphatics and arterioles; in technique which can speed diagnosis and institution of therapy in lymphangitic carcinomatosis.

  18. 2D imaging of functional structures in perfused pig heart

    NASA Astrophysics Data System (ADS)

    Kessler, Manfred D.; Cristea, Paul D.; Hiller, Michael; Trinks, Tobias

    2002-06-01

    In 2000 by 2D-imaging we were able for the first time to visualize in subcellular space functional structures of myocardium. For these experiments we used hemoglobin-free perfused pig hearts in our lab. Step by step we learned to understand the meaning of subcellular structures. Principally, the experiment revealed that in subcellular space very fast changes of light scattering can occur. Furthermore, coefficients of different parameters were determined on the basis of multicomponent system theory.

  19. Properties of sodium pumps in internally perfused barnacle muscle fibers.

    PubMed

    Nelson, M T; Blaustein, M P

    1980-02-01

    To study the properties of the Na extrusion mechanism, giant muscle fibers from barnacle (Balanus nubilus) were internally perfused with solutions containing tracer 22Na. In fibers perfused with solutions containing adenosine 5'-triphosphate (ATP) and 30 mM Na, the Na efflux into 10 mM K seawater was approximately 25-30 pmol/cm2.s; 70% of this efflux was blocked by 50-100 microM ouabain, and approximately 30% was blocked by removal of external K. The ouabain-sensitive and K-dependent Na effluxes were abolished by depletion of internal ATP and were sigmoid-shaped functions of the internal Na concentration ([Na]i), with half-maxima at [Na]i approximately or equal to 20 mM. These sigmoid functions fit the Hill equation with Hill coefficients of approximately 3.5. Ouabain depolarized ATP-fueled fibers by 1.5-2 mV ([Na]i greater than or equal to 30 mM) but had very little effect on the membrane potential of ATP-depleted fibers; ATP depletion itself caused a 2-2.5-mV depolarization. When fueled fibers were treated with 3,4-diaminopyridine or Ba2+ (to reduce the K conductance and increase membrane resistance), application of ouabain produced a 4-5 mV depolarization. These results indicate that an electrogenic, ATP-dependent Na-K exchange pump is functional in internally perfused fibers; the internal perfusion technique provides a convenient method for performing transport studies that require good intracellular solute control. PMID:7373278

  20. Sublingual microvascular perfusion is altered during normobaric and hyperbaric hyperoxia.

    PubMed

    Milstein, Dan M J; Helmers, Renée; Hackmann, Sanne; Belterman, Charly N W; van Hulst, Robert A; de Lange, Jan

    2016-05-01

    Hyperoxia and hyperbaric oxygen therapy can restore oxygen tensions in tissues distressed by ischemic injury and poor vascularization and is believed to also yield angiogenesis and regulate tissue perfusion. The aim of this study was to develop a model in which hyperoxia-driven microvascular changes could be quantified and to test the hypothesis that microcirculatory responses to both normobaric (NB) and hyperbaric (HB) hyperoxic maneuvers are reversible. Sublingual mucosa microcirculation vessel density, proportion of perfused vessels, vessel diameters, microvascular flow index, macrohemodynamic, and blood gas parameters were examined in male rabbits breathing sequential O2/air mixtures of 21%, 55%, 100%, and return to 21% during NB (1.0bar) and HB (2.5bar) conditions. The results indicate that NB hyperoxia (55% and 100%) produced significant decreases in microvascular density and vascular diameters (p<0.01 and p<0.05, respectively) accompanied by significant increases in systolic and mean arterial blood pressure (p<0.05, respectively) with no changes in blood flow indices when compared to NB normoxia. HB normoxia/hyperoxia resulted in significant decreases in microvascular density (p<0.05), a transient rise in systolic blood pressure at 55% (p<0.01), and no changes in blood vessel diameter and blood flow indices when compared to NB hyperoxia. All microcirculation parameters reverted back to normal values upon return to NB normoxia. We conclude that NB/HB hyperoxia-driven changes elicit reversible physiological control of sublingual mucosa blood perfusion in the presence of steady cardiovascular function and that the absence of microvascular vasoconstriction during HB conditions suggests a beneficial mechanism associated with maintaining peak tissue perfusion states. PMID:26851620

  1. Cardiac PET Perfusion Tracers: Current Status and Future Directions

    PubMed Central

    Maddahi, Jamshid; Packard, René R. S.

    2015-01-01

    Positron emission tomography (PET) myocardial perfusion imaging (MPI) is increasingly used for non-invasive detection and evaluation of coronary artery disease (CAD). However, the widespread use of PET MPI has been limited by shortcomings of the current PET perfusion tracers. Availability of these tracers is limited by need for an on-site (15O water and 13N ammonia) or nearby (13N ammonia) cyclotron or commitment to costly generators (82Rb). Due to short half-lives ranging from 76sec for 82Rb, to 2.1min for 15O water and 10min for 13N ammonia, their use in conjunction with treadmill exercise stress testing is either not possible (82Rb and 15O water) or is not practical (13N ammonia). Furthermore, the long positron range of 82Rb makes image resolution suboptimal and its low extraction limits its defect resolution. In recent years, development of an 18F labeled PET perfusion tracer has gathered considerable interest. The longer half-life of 18F (108 minutes) would make the tracer available as a unit dose from regional cyclotrons and allow use in conjunction with treadmill exercise testing. Furthermore, the short positron range of 18F would result in better image resolution. 18F flurpiridaz is by far the most thoroughly studied in animal models, and is the only F18-based PET MPI radiotracer currently undergoing clinical evaluation. Pre-clinical and clinical experience with 18F flurpiridaz demonstrated a high myocardial extraction fraction, high image and defect resolution, high myocardial uptake, slow myocardial clearance, and high myocardial-to-background contrast which was stable over time – important properties of an ideal PET MPI radiotracer. Pre-clinical data from other 18F labeled myocardial perfusion tracers are encouraging. PMID:25234078

  2. Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging

    SciTech Connect

    Cao Yue; Wang Hesheng; Johnson, Timothy D.; Pan, Charlie; Hussain, Hero; Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary

    2013-01-01

    Purpose: To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials: Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results: There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions: This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which

  3. Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging

    PubMed Central

    Cao, Yue; Wang, Hesheng; Johnson, Timothy D.; Pan, Charlie; Hussain, Hero; Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary

    2013-01-01

    Purpose To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which

  4. Diffusion and perfusion MRI of the lung and mediastinum.

    PubMed

    Henzler, Thomas; Schmid-Bindert, Gerald; Schoenberg, Stefan O; Fink, Christian

    2010-12-01

    With ongoing technical improvements such as multichannel MRI, systems with powerful gradients as well as the development of innovative pulse sequence techniques implementing parallel imaging, MRI has now entered the stage of a radiation-free alternative to computed tomography (CT) for chest imaging in clinical practice. Whereas in the past MRI of the lung was focused on morphological aspects, current MRI techniques also enable functional imaging of the lung allowing for a comprehensive assessment of lung disease in a single MRI exam. Perfusion imaging can be used for the visualization of regional pulmonary perfusion in patients with different lung diseases such as lung cancer, chronic obstructive lung disease, pulmonary embolism or for the prediction of postoperative lung function in lung cancer patients. Over the past years diffusion-weighted MR imaging (DW-MRI) of the thorax has become feasible with a significant reduction of the acquisition time, thus minimizing artifacts from respiratory and cardiac motion. In chest imaging, DW-MRI has been mainly suggested for the characterization of lung cancer, lymph nodes and pulmonary metastases. In this review article recent MR perfusion and diffusion techniques of the lung and mediastinum as well as their clinical applications are reviewed. PMID:20627435

  5. A microfluidically perfused three dimensional human liver model.

    PubMed

    Rennert, Knut; Steinborn, Sandra; Gröger, Marko; Ungerböck, Birgit; Jank, Anne-Marie; Ehgartner, Josef; Nietzsche, Sandor; Dinger, Julia; Kiehntopf, Michael; Funke, Harald; Peters, Frank T; Lupp, Amelie; Gärtner, Claudia; Mayr, Torsten; Bauer, Michael; Huber, Otmar; Mosig, Alexander S

    2015-12-01

    Within the liver, non-parenchymal cells (NPCs) are critically involved in the regulation of hepatocyte polarization and maintenance of metabolic function. We here report the establishment of a liver organoid that integrates NPCs in a vascular layer composed of endothelial cells and tissue macrophages and a hepatic layer comprising stellate cells co-cultured with hepatocytes. The three-dimensional liver organoid is embedded in a microfluidically perfused biochip that enables sufficient nutrition supply and resembles morphological aspects of the human liver sinusoid. It utilizes a suspended membrane as a cell substrate mimicking the space of Disse. Luminescence-based sensor spots were integrated into the chip to allow online measurement of cellular oxygen consumption. Application of microfluidic flow induces defined expression of ZO-1, transferrin, ASGPR-1 along with an increased expression of MRP-2 transporter protein within the liver organoids. Moreover, perfusion was accompanied by an increased hepatobiliary secretion of 5(6)-carboxy-2',7'-dichlorofluorescein and an enhanced formation of hepatocyte microvilli. From this we conclude that the perfused liver organoid shares relevant morphological and functional characteristics with the human liver and represents a new in vitro research tool to study human hepatocellular physiology at the cellular level under conditions close to the physiological situation. PMID:26322723

  6. Inhomogeneity of pulmonary perfusion during sustained microgravity on SLS-1.

    PubMed

    Prisk, G K; Guy, H J; Elliott, A R; West, J B

    1994-04-01

    We studied the effects of gravity on the inhomogeneity of pulmonary perfusion in humans by performing hyperventilation-breath-hold single-breath measurements before, during, and after 9 days of continuous exposure to microgravity during the Spacelab Life Sciences-1 (SLS-1) mission. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase IV, were markedly reduced. Cardiogenic oscillations were reduced to approximately 60% of their preflight standing size, and the height of phase IV was between 0 and -8% (a terminal fall became a small terminal rise) of the preflight standing value. The terminal change in expired CO2 was nearly abolished in microgravity, indicating more uniformity of blood flow between lung units that close and those that remain open at the end of expiration. A possible explanation of this observation is the disappearance of gravity-dependent topographic inequality of blood flow. The residual cardiogenic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity, probably in lung regions that are not within the same acinus. PMID:8045853

  7. Inhomogeneity of pulmonary perfusion during sustained microgravity on SLS-1

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; West, John B.

    1994-01-01

    We studied the effects of gravity on the inhomogeneity of pulmonary perfusion in humans by performing hyperventilation-breath-hold single-breath measurements before, during, and after 9 days of continuous exposure to microgravity during the Spacelab Life Sciences-1 (SLS-1) mission. In microgravity the indicators of inhomogeneity of perfusion, especially the size of cardiogenic oscillations in expired CO2 and the height of phase IV, were markedly reduced. Cardiogenic oscillations were reduced to approximately 60% of their preflight standing size, and the height of phase IV was between 0 and -8% (a terminal fall became a small terminal rise) of the preflight standing value. The terminal change in expired CO2 was nearly abolished in microgravity, indicating more uniformity of blood flow between lung units that close and those that remain open at the end of expiration. A possible explanation of this observation is the disappearance of gravity-dependent topographic inequality of blood flow. The residual cardiogenic oscillations in expired CO2 imply a persisting inhomogeneity of perfusion in the absence of gravity, probably in lung regions that are not within the same acinus.

  8. Mapping resting-state functional connectivity using perfusion MRI

    PubMed Central

    Chuang, Kai-Hsiang; van Gelderen, Peter; Merkle, Hellmut; Bodurka, Jerzy; Ikonomidou, Vasiliki N.; Koretsky, Alan P.; Duyn, Jeff H.; Talagala, S. Lalith

    2008-01-01

    Resting-state, low frequency (< 0.08 Hz) fluctuations of blood oxygenation level dependent (BOLD) magnetic resonance signal have been shown to exhibit high correlation among functionally connected regions. However, correlations of cerebral blood flow (CBF) fluctuations during the resting state have not been extensively studied. The main challenges of using arterial spin labeling perfusion magnetic resonance imaging to detect CBF fluctuations are low sensitivity, low temporal resolution, and contamination from BOLD. This work demonstrates CBF-based quantitative functional connectivity mapping by combining continuous arterial spin labeling (CASL) with a neck labeling coil and a multi-channel receiver coil to achieve high perfusion sensitivity. In order to reduce BOLD contamination, the CBF signal was extracted from the CASL signal time course by high frequency filtering. This processing strategy is compatible with sinc interpolation for reducing the timing mismatch between control and label images and has the flexibility of choosing an optimal filter cutoff frequency to minimize BOLD fluctuations. Most subjects studied showed high CBF correlation in bilateral sensorimotor areas with good suppression of BOLD contamination. Root-mean-square CBF fluctuation contributing to bilateral correlation was estimated to be 29% ± 19% (N = 13) of the baseline perfusion, while BOLD fluctuation was 0.26% ± 0.14% of the mean intensity (at 3T and 12.5 ms echo time). PMID:18314354

  9. MR mapping of temperature and perfusion for hyperthermia therapy

    NASA Astrophysics Data System (ADS)

    Wlodarczyk, Waldemar; Vlad, Julia; Lange, Thomas; Wust, Peter; Felix, Roland

    2001-05-01

    The promising results, recently obtained in phantom experiments employing the MR-based proton resonance frequency (PRF) method as a non-invasive tool for the temperature monitoring of hyperthermia therapy, are not easily reproduced in vivo. One of the reasons is the impact of perfusion changes on the PRF-measured temperature. In our experiments in vivo, heat was supplied on one side of the volunteers knee or pelvis by a rubber hose with circulating warm water (50iC). The PRF method was calibrated by the constant temperature sensitivity of pure water of 0.011 ppm/iC. MR mapping of perfusion changes was based on T2*-weighted tracking of the first-pass kinetics of contrast agent. The hemodynamic parameters of regional blood volume (rBV) and mean transit time (MTT) were extracted by fitting pixel-by-pixel the first- pass kinetics to the gamma-variate model. Special attention was directed to improve a quality of the automatic non-linear fit at low signal-to-noise values. The distributions of PRF- based temperature changes show large areas of apparently high temperature elevations (exceeding 10iC) in regions close to the heat source, and others with just as large temperature decays in more distant regions. Areas of apparently high temperature elevations correlate with areas of blood flow increase and vice versa. In conclusion, the visible heat- induced PRF changes in vivo are primarily perfusion changes, which mask the much smaller true temperature changes.

  10. Parametric imaging of tumor perfusion and neovascular morphology using ultrasound

    NASA Astrophysics Data System (ADS)

    Hoyt, Kenneth

    2015-03-01

    A new image processing strategy is detailed for the simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. A technique for locally mapping tumor perfusion parameters using skeletonized neovascular data is also introduced. Simulated images were used to test the neovascular skeletonization technique and variance (error) of relevant parametric estimates. Preliminary DCE-US image datasets were collected in 6 female patients diagnosed with invasive breast cancer and using a Philips iU22 ultrasound system equipped with a L9-3 MHz transducer and Definity contrast agent. Simulation data demonstrates that neovascular morphology parametric estimation is reproducible albeit measurement error can occur at a lower signal-to-noise ratio (SNR). Experimental results indicate the feasibility of our approach to performing both tumor perfusion and neovascular morphology measurements from DCE-US images. Future work will expand on our initial clinical findings and also extent our image processing strategy to 3-dimensional space to allow whole tumor characterization.

  11. Ventilation-perfusion matching in long-term microgravity

    NASA Technical Reports Server (NTRS)

    Verbandt, Y.; Wantier, M.; Prisk, G. K.; Paiva, M.; West, J. B. (Principal Investigator)

    2000-01-01

    We studied the ventilation-perfusion matching pattern in normal gravity (1 G) and short- and long-duration microgravity (microG) using the cardiogenic oscillations in the sulfur hexaflouride (SF(6)) and CO(2) concentration signals during the phase III portion of vital capacity single-breath washout experiments. The signal power of the cardiogenic concentration variations was assessed by spectral analysis, and the phase angle between the oscillations of the two simultaneously expired gases was obtained through cross-correlation. For CO(2), a significant reduction of cardiogenic power was observed in microG, with respect to 1 G, but the reduction was smaller and more variable in the case of SF(6). A shift from an in-phase condition in 1 G to an out-of-phase condition was found for both short- and long-duration microG. We conclude that, although the distribution of ventilation and perfusion becomes more homogeneous in microG, significant inhomogeneities persist and that areas of high perfusion become associated with areas of relatively lower ventilation. In addition, these modifications seem to remain constant during long-term exposure to microG.

  12. Single perfusion defect and pulmonary embolism: Angiographic correlation

    SciTech Connect

    Catania, T.A.; Caride, V.J. )

    1990-03-01

    One hundred and thirty-three ventilation-perfusion scans (V-P) with angiographic correlation were retrospectively reviewed to evaluate the frequency of pulmonary emboli (PE) in single perfusion defects (SPD), regardless of ventilation or radiographic findings. By angiography, 15 of 30 SPD cases had PE. Demographic data and clinical presentation were similar for PE and non-PE patients. However, 9 out of 15 patients with PE had recent surgery compared to none of the non-PE patients. SPD were seen in areas of ventilation and chest x-ray abnormalities in 12 of 15 PE and 11 of 19 non-PE cases. Size of the actual lesion was underestimated by scintigraphy in most cases. In 7 of 15 PE cases, the perfusion defect was larger than the corresponding ventilation abnormality. Most SPD were located at the bases. Twelve of 15 SPD in the PE group were at the posterior basilar segment. In the appropriate clinical setting, SPD carries at least a moderate probability for PE. When the clinical suspicion is high, a pulmonary angiography will be needed to confirm the diagnosis.

  13. Psychosis of Alzheimer's disease: Gender differences in regional perfusion.

    PubMed

    Moran, E K; Becker, J A; Satlin, A; Lyoo, In Kyoon; Fischman, A J; Johnson, K A

    2008-08-01

    We sought to determine whether the presence of psychotic symptoms in patients with Alzheimer's disease is associated with abnormal regional cerebral function. Perfusion single photon emission computed tomography images from 51 AD patients with psychotic symptoms were compared to images of 52 AD patients without such symptoms. Group comparisons were made with a voxel-based method, Statistical Parametric Mapping. We found that perfusion was lower in female patients with psychotic symptoms in right infero-lateral prefrontal cortex and in inferior temporal regions compared to female patients without such symptoms. In contrast, perfusion was higher in male patients with psychotic symptoms in the right striatum compared to male patients without such symptoms. Comparison groups did not differ in age or in dementia severity, as estimated by the Mini-Mental State Examination (MMSE). These results support the role of right hemisphere prefrontal and lateral temporal cortex in the psychosis of AD in women but not in men, and raise the possibility that these dysfunctional processes have a gender-specific regional pathophysiology in AD. PMID:17408808

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

    NASA Astrophysics Data System (ADS)

    Teng, Yichao; Ding, HaiShu