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Sample records for cerebral perfusion imaging

  1. Cerebral perfusion imaging using contrast-enhanced MRI

    International Nuclear Information System (INIS)

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

  2. Personal computer aided cerebral perfusion imaging with dynamic CT

    Institute of Scientific and Technical Information of China (English)

    林燕; 高培毅

    2004-01-01

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

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

    Science.gov (United States)

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

    2010-02-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Pivawer, Gabriel; Law, Meng; Zagzag, David

    2006-01-01

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

  6. Methodological NMR imaging developments to measure cerebral perfusion

    International Nuclear Information System (INIS)

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

  7. Perfusion and diffusion MR imaging of cerebral ischemia

    International Nuclear Information System (INIS)

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

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

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

    2012-04-15

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

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

    Science.gov (United States)

    Pivawer, Gabriel; Law, Meng; Zagzag, David

    2007-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  11. Noninvasive Cerebral Perfusion Imaging in High-Risk Neonates

    OpenAIRE

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

    2010-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    施辛; 吴锦昌; 刘增礼; 唐军; 苏玉华

    2003-01-01

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

  13. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  17. Perfusion MRI in cerebral infarction

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

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

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

    2016-03-15

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

  2. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2000-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Ida,Kentaro

    2006-08-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2016-05-01

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Jianping Dai

    2006-10-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  14. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-03-15

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

  15. Diffusion and Perfusion MRI in Acute Cerebral Ischemia

    Institute of Scientific and Technical Information of China (English)

    Tchoyoson CC Lim; Chong-Tin Tan

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2011-01-01

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

  18. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-01-01

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

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

    International Nuclear Information System (INIS)

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

  2. Laser doppler perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 {mu}m. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs.

  3. Laser doppler perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Waardell, K.

    1992-11-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 {mu}m. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs.

  4. Laser doppler perfusion imaging

    International Nuclear Information System (INIS)

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

  5. 99mTc-ECD brain perfusion SPECT imaging for the assessment of brain perfusion in cerebral palsy (CP) patients with evaluation of the effect of hyperbaric oxygen therapy

    OpenAIRE

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  8. Computed tomography perfusion imaging in acute stroke

    International Nuclear Information System (INIS)

    The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel-by-pixel analysis allowed generation of perfusion maps. In two cases, CT-perfusion imaging usefully excluded acute stroke, including one patient in whom a low-density area on conventional CT was subsequently proven to be tumour Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non-haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis. Copyright (2002) Blackwell Science Pty Ltd

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

    International Nuclear Information System (INIS)

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

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

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

    2014-01-15

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

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    Inseon Ryoo

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

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

    International Nuclear Information System (INIS)

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

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

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

    2013-08-15

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

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

    International Nuclear Information System (INIS)

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

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

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

    2011-03-15

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  20. Cerebral perfusion deficits in divers with neurological decompression illness

    International Nuclear Information System (INIS)

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

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

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    Joanna Bladowska

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

  2. Acute stroke: the role of CT perfusion imaging

    International Nuclear Information System (INIS)

    Full text: The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the evaluation of acute stroke. This report illustrates the value of perfusion CT in the assessment of suspected acute stroke. Five cases are presented. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel by pixel analysis allowed generation of perfusion maps. Infarction is associated with reduced CBF and CBV whereas preserved CBV in the presence of reduced CBF implies intact autoregulation and hence potentially salvageable tissue (ie penumbra). The size of the perfusion defect indicates prognosis. In two cases, CT perfusion imaging usefully excluded acute stroke, including one patient in whom a low density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with nonhaemorrhage stroke in the presence of a normal conventional CT, to select those patients for whom thrombolysis is appropriate, and to provide an indication as to prognosis. Copyright (2002) Blackwell Science Pty Ltd

  3. CT angiography and perfusion imaging in patients with subarachnoid hemorrhage: correlation of vasospasm to perfusion abnormality

    International Nuclear Information System (INIS)

    We retrospectively evaluated computed tomography angiography (CTA) and perfusion imaging (CTP) of patients with aneurysmal subarachnoid hemorrhage (SAH) for any correlation between degree of vasospasm and perfusion deficit. Sequentially performed CTP and CTA of 41 patients at least at the third day of postbleeding were reviewed for vasospasm and perfusion deficit throughout the anterior and middle cerebral arteries and corresponding territories. Vasospasm was noted comparing the contralateral normal ones or extradural components of the vessel itself and graded to negative, mild, moderate, and severe as luminal narrowing none, <25%, between 25% and 50%, and ≥50%, respectively. CTP abnormality was noted using cerebral blood flow and volume and mean transit time maps. Of 41 patients, 20 had no vasospasm; 15 had mild to moderate and six had severe vasospasm. Three of 20 patients with no vasospasm (15%), four of 15 patients with mild to moderate vasospasm (26%), and five of six patients with severe vasospasm (83%) had perfusion abnormality. Perfusion abnormalities noted were ischemia, infarction, and hyperperfusion. Perfusion abnormality without vasospasm was observed in the watershed areas and adjacent to sulcal clots. In SAH patients, if there is a macrovascular vasospasm with luminal narrowing ≥50%, there is a high likelihood (83%) of perfusion abnormality in the territory of the vasospastic vessel. There may also be perfusion abnormality without macrovascular vasospasm in the watershed areas or in the vicinity of sulcal clots. (orig.)

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

    CERN Document Server

    Cluckie, A J

    2001-01-01

    Neurological images may be analysed by performing voxel by voxel comparisons with a group of control subject images. An automated, 3D, voxel-based method has been developed for the analysis of individual single photon emission tomography (SPET) scans. Clusters of voxels are identified that represent regions of abnormal radiopharmaceutical uptake. Morphological operators are applied to reduce noise in the clusters, then quantitative estimates of the size and degree of the radiopharmaceutical uptake abnormalities are derived. Statistical inference has been performed using a Monte Carlo method that has not previously been applied to SPET scans, or for the analysis of individual images. This has been validated for group comparisons of SPET scans and for the analysis of an individual image using comparison with a group. Accurate statistical inference was obtained independent of experimental factors such as degrees of freedom, image smoothing and voxel significance level threshold. The analysis method has been eval...

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

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    Andreas Habertheuer

    2015-01-01

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

  6. Quantitative perfusion imaging in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.)

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

    Institute of Scientific and Technical Information of China (English)

    曾裕镜

    2008-01-01

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

  8. Magnetic resonance spectroscopy and imaging in cerebral ischemia

    International Nuclear Information System (INIS)

    In-vivo proton and phosphorus magnetic resonance spectroscopy was used to detect changes in cerebral metabolism during ischemia and other types of metabolic stress. Magnetic resonance imaging was performed in an animal model to observe morphological alterations during focal cerebral ischemia. Spectroscopy was performed in animal models with global ischemia, in volunteers during hyperventilation and pharmaco-logically altered cerebral perfusion, and in patients with acute and prolonged focal cerebral ischemia. (author). 396 refs.; 44 figs.; 14 tabs

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  10. Perfusion-weighted MR imaging in persistent hemiplegic migraine

    Energy Technology Data Exchange (ETDEWEB)

    Mourand, Isabelle; Menjot de Champfleur, Nicolas; Carra-Dalliere, Clarisse; Le Bars, Emmanuelle; Bonafe, Alain; Thouvenot, Eric [Hopital Gui de Chauliac, Service de Neuroradiologie, Montpellier (France); Roubertie, Agathe [Hopital Gui de Chauliac, Service de Neuropediatrie, Montpellier (France)

    2012-03-15

    Hemiplegic migraine is a rare type of migraine that has an aura characterized by the presence of motor weakness, which may occasionally last up to several days, and then resolve without sequela. Pathogenesis of migraine remains unclear and, recently, perfusion-weighted imaging (PWI) has provided a non-invasive method to study hemodynamic changes during acute attacks. Two female patients were admitted in our hospital suffering from prolonged hemiparesis. In both cases, they underwent MRI examination using a 1.5 T magnet including axial diffusion-weighted and perfusion sequences. From each perfusion MRI acquisition two regions of interest were delineated on each hemisphere and, the index of flow, cerebral blood volume, mean transit time, and time to peak were recorded and asymmetry indices from each perfusion parameter were calculated. Perfusion alterations were detected during the attacks. In one case, we observed, after 3 h of left hemiparesia, hypoperfusion of the right hemisphere. In the other case, who presented a familial hemiplegic migraine attack, on the third day of a persistent aura consisting of right hemiplegia and aphasia, PWI revealed hyperperfusion of the left hemisphere. Asymmetry indices for temporal parameters (mean transit time and time to peak) were the most sensitive. These findings resolved spontaneously after the attacks without any permanent sequel or signs of cerebral ischemia on follow-up MRI. PWI should be indicated for patients with migraine attacks accompanied by auras to assess the sequential changes in cerebral perfusion and to better understand its pathogenesis. (orig.)

  11. Perfusion-weighted MR imaging in persistent hemiplegic migraine

    International Nuclear Information System (INIS)

    Hemiplegic migraine is a rare type of migraine that has an aura characterized by the presence of motor weakness, which may occasionally last up to several days, and then resolve without sequela. Pathogenesis of migraine remains unclear and, recently, perfusion-weighted imaging (PWI) has provided a non-invasive method to study hemodynamic changes during acute attacks. Two female patients were admitted in our hospital suffering from prolonged hemiparesis. In both cases, they underwent MRI examination using a 1.5 T magnet including axial diffusion-weighted and perfusion sequences. From each perfusion MRI acquisition two regions of interest were delineated on each hemisphere and, the index of flow, cerebral blood volume, mean transit time, and time to peak were recorded and asymmetry indices from each perfusion parameter were calculated. Perfusion alterations were detected during the attacks. In one case, we observed, after 3 h of left hemiparesia, hypoperfusion of the right hemisphere. In the other case, who presented a familial hemiplegic migraine attack, on the third day of a persistent aura consisting of right hemiplegia and aphasia, PWI revealed hyperperfusion of the left hemisphere. Asymmetry indices for temporal parameters (mean transit time and time to peak) were the most sensitive. These findings resolved spontaneously after the attacks without any permanent sequel or signs of cerebral ischemia on follow-up MRI. PWI should be indicated for patients with migraine attacks accompanied by auras to assess the sequential changes in cerebral perfusion and to better understand its pathogenesis. (orig.)

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

    OpenAIRE

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-15

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

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

    International Nuclear Information System (INIS)

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

  15. Measurements of diagnostic examination performance and correlation analysis using microvascular leakage, cerebral blood volume, and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading

    International Nuclear Information System (INIS)

    To assess the diagnostic accuracy of microvascular leakage (MVL), cerebral blood volume (CBV) and blood flow (CBF) values derived from dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging (DSC-MR imaging) for grading of cerebral glial tumors, and to estimate the correlation between vascular permeability/perfusion parameters and tumor grades. A prospective study of 79 patients with cerebral glial tumors underwent DSC-MR imaging. Normalized relative CBV (rCBV) and relative CBF (rCBF) from tumoral (rCBVt and rCBFt), peri-enhancing region (rCBVe and rCBFe), and the value in the tumor divided by the value in the peri-enhancing region (rCBVt/e and rCBFt/e), as well as MVL, expressed as the leakage coefficient K2 were calculated. Hemodynamic variables and tumor grades were analyzed statistically and with Pearson correlations. Receiver operating characteristic (ROC) curve analyses were also performed for each of the variables. The differences in rCBVt and the maximum MVL (MVLmax) values were statistically significant among all tumor grades. Correlation analysis using Pearson was as follows: rCBVt and tumor grade, r = 0.774; rCBFt and tumor grade, r = 0.417; MVLmax and tumor grade, r = 0.559; MVLmax and rCBVt, r = 0.440; MVLmax and rCBFt, r = 0.192; and rCBVt and rCBFt, r = 0.605. According to ROC analyses for distinguishing tumor grade, rCBVt showed the largest areas under ROC curve (AUC), except for grade III from IV. Both rCBVt and MVLmax showed good discriminative power in distinguishing all tumor grades. rCBVt correlated strongly with tumor grade; the correlation between MVLmax and tumor grade was moderate. (orig.)

  16. Displaying perfusion MRI images as color intensity projections

    CERN Document Server

    Hoefnagels, Friso; Sanchez, Ester; Lagerwaard, Frank J

    2007-01-01

    Dynamic susceptibility-weighted contrast-enhanced (DSC) MRI or perfusion-MRI plays an important role in the non-invasive assessment of tumor vascularity. However, the large number of images provided by the method makes display and interpretation of the results challenging. Current practice is to display the perfusion information as relative cerebral blood volume maps (rCBV). Color intensity projections (CIPs) provides a simple, intuitive display of the perfusion-MRI data so that regional perfusion characteristics are intrinsically integrated into the anatomy structure the T2 images. The ease of use and quick calculation time of CIPs should allow it to be easily integrated into current analysis and interpretation pipelines.

  17. Dosimetry in myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  18. Dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

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

    Science.gov (United States)

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

    2016-03-01

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

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

    DEFF Research Database (Denmark)

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

    1988-01-01

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

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

    OpenAIRE

    Podolsky Yu.S.; Hapy I.H.

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

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

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

    International Nuclear Information System (INIS)

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

  4. Multi-delay arterial spin labeling perfusion MRI in moyamoya disease-comparison with CT perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui [Chinese Academy of Sciences, State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Beijing (China); University of Chinese Academy of Sciences, Graduate School, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Los Angeles, CA (United States); Yu, Songlin [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); University of California Los Angeles, Department of Neurology, Los Angeles (United States); Alger, Jeffry R.; Wang, Danny J.J. [University of California Los Angeles, Department of Neurology, Los Angeles (United States); UCLA-Beijing Joint Center for Advanced Brain Imaging, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Los Angeles, CA (United States); Zuo, Zhentao; Wang, Bo [Chinese Academy of Sciences, State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Beijing (China); Chen, Juan [Beijing Hospital, Department of Radiology, Beijing (China); Wang, Rong; Zhao, Jizong [Capital Medical University, Department of Neurosurgery, Beijing Tiantan Hospital, Beijing (China); An, Jing [Siemens Shenzhen Magnetic Resonance Ltd, Shenzhen (China); Xue, Rong [Chinese Academy of Sciences, State Key Laboratory of Brain and Cognitive Science, Beijing MRI Center for Brain Research, Institute of Biophysics, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Beijing (China); UCLA-Beijing Joint Center for Advanced Brain Imaging, Los Angeles, CA (United States)

    2014-05-15

    To present a multi-delay pseudo-continuous ASL (pCASL) protocol that offers simultaneous measurements of cerebral blood flow (CBF) and arterial transit time (ATT), and to study correlations between multi-delay pCASL and CT perfusion in moyamoya disease. A 4 post-labeling delay (PLD) pCASL protocol was applied on 17 patients with moyamoya disease who also underwent CT perfusion imaging. ATT was estimated using the multi-delay protocol and included in the calculation of CBF. ASL and CT perfusion images were rated for lesion severity/conspicuity. Pearson correlation coefficients were calculated across voxels between the two modalities in grey and white matter of each subject respectively and between normalized mean values of ASL and CT perfusion measures in major vascular territories. Significant associations between ASL and CT perfusion were detected using subjective ratings, voxel-wise analysis in grey and white matter and region of interest (ROI)-based analysis of normalized mean perfusion. The correlation between ASL CBF and CT perfusion was improved using the multi-delay pCASL protocol compared to CBF acquired at a single PLD of 2 s (P < 0.05). There is a correlation between perfusion data from ASL and CT perfusion imaging in patients with moyamoya disease. Multi-delay ASL can improve CBF quantification, which could be a prognostic imaging biomarker in patients with moyamoya disease. (orig.)

  5. Multi-delay arterial spin labeling perfusion MRI in moyamoya disease-comparison with CT perfusion imaging

    International Nuclear Information System (INIS)

    To present a multi-delay pseudo-continuous ASL (pCASL) protocol that offers simultaneous measurements of cerebral blood flow (CBF) and arterial transit time (ATT), and to study correlations between multi-delay pCASL and CT perfusion in moyamoya disease. A 4 post-labeling delay (PLD) pCASL protocol was applied on 17 patients with moyamoya disease who also underwent CT perfusion imaging. ATT was estimated using the multi-delay protocol and included in the calculation of CBF. ASL and CT perfusion images were rated for lesion severity/conspicuity. Pearson correlation coefficients were calculated across voxels between the two modalities in grey and white matter of each subject respectively and between normalized mean values of ASL and CT perfusion measures in major vascular territories. Significant associations between ASL and CT perfusion were detected using subjective ratings, voxel-wise analysis in grey and white matter and region of interest (ROI)-based analysis of normalized mean perfusion. The correlation between ASL CBF and CT perfusion was improved using the multi-delay pCASL protocol compared to CBF acquired at a single PLD of 2 s (P < 0.05). There is a correlation between perfusion data from ASL and CT perfusion imaging in patients with moyamoya disease. Multi-delay ASL can improve CBF quantification, which could be a prognostic imaging biomarker in patients with moyamoya disease. (orig.)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  11. Perfusion imaging with single-photon emission computed tomography

    International Nuclear Information System (INIS)

    SPECT with perfusion tracers is useful in a number of circumstances: (1) In acute cerebral infarction while the CT scan may be normal for several days after onset of symptoms, the uptake of SPECT perfusion tracers will be altered immediately after the onset of the stroke. Even when the CT scan has become abnormal, the physiologic abnormality may exceed the anatomic abnormality. One may, therefore be able to measure the extent of the reversibly ischemic tissue early enough to justify more agressive therapeutic interventions. (2) For endarterectomy and other surgical and medical therapies serial measurements of regional cerebral perfusion with SPECT may provide a readily available tool to assess their efficacy. (3) SPECT perfusion imaging may become the method of choice for the diagnosis and evaluation of Alzheimer's disease. (4) In patients with epilepsy, the extent and location of the abnormally perfused focus may be important to medical and surgical management. Follow-up examination may be useful in documenting the effectiveness of therapy

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

    International Nuclear Information System (INIS)

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

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

    Institute of Scientific and Technical Information of China (English)

    陈唯唯; 漆剑频; 张进华; 黄文华; 宋金梅

    2004-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  15. 磁共振灌注加权成像在颅脑胶质瘤分级中的价值研究%Value of MR perfusion weighted imaging in differentiating the tumor grade of cerebral gliomas

    Institute of Scientific and Technical Information of China (English)

    李伟; 龙晚生; 罗学毛; 何义改; 兰勇; 蔡小琴

    2011-01-01

    目的 探讨相对脑血容积(rCBV)、相对脑血流量(rCBF)和相对平均通过时间(rMTT)在鉴别颅脑胶质瘤病理分级中的价值.方法 对病理证实为颅脑胶质瘤的患者(Ⅱ级胶质瘤9例,Ⅲ级胶质瘤11例,Ⅳ级胶质瘤14例)行MR灌注加权成像及常规MRI检查.由灌注加权成像数据获取脑血容积(CBV)图、脑血流量(CBF)图和平均通过时间(MTT)图,计算出rCBV、rCBF和rMTT值.结果 Ⅱ级胶质瘤的rCBV、rCBF和rMTT值分别为2.68±1.37、2.52±1.29和1.02±0.30,Ⅲ级胶质瘤的rCBV、rCBF和rMTT值分别为4.99±2.34、4.77±1.97和1.07±0.15,Ⅳ级胶质瘤的rCBV、rCBF和rMTT值分别为6.69±1.88、6.97±1.73和1.08±0.22,各组间rCBV和rCBF值比较差异有统计学意义(P0.05).结论 MR灌注加权成像能有效地在术前评价颅脑胶质瘤的病理级别,rCBV值结合rCBF值可以更好地对颅脑胶质瘤进行病理分级.%Objective To explore the value of relative cerebral blood volume(rCBV), relative cerebral blood flow(rCBF) and relative mean through time(rMTT) in differentiating the tumor grade of cerebral gliomas. Methods This study involved 34 patients (9 cases of grade Ⅱ,11 cases of grade Ⅲ,14 cases of grade Ⅳ) which were identified as gliomas proved by histopathologic. MR perfusion weighted imaging and conventional MR imaging were underwent on them preoperatively. The perfusion weighted imaging datas were deconvoluted to get a color map of CBV, CBF and MTT. The value of rCBV, rCBF and rMTT of each lesion were calculated and correlated with histopathologic grading of gliomas. Results The value of rCBV, rCBF and rMTT of grade Ⅱ,grade Ⅲ,grade Ⅳ gliomas was (2.68±1.37, 4.99±2.34,6.69±1.88), (2.52±1.29,4.77±1.97,6.97±1.73) and (1.02±0.30,1.07±0.15,1.08±0.22), respectively. The value of rCBV and rCBF had statistically difference in each groups (P0.05).Conclusions MR perfusion weighted imaging is useful in the preoperative assessment of the histopathologic grade

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Niklaus eDenier

    2013-10-01

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

  18. Advanced Imaging Modalities in the Detection of Cerebral Vasospasm

    OpenAIRE

    Mills, Jena N.; Vivek Mehta; Jonathan Russin; Amar, Arun P.; Anandh Rajamohan; William J. Mack

    2013-01-01

    The pathophysiology of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is complex and is not entirely understood. Mechanistic insights have been gained through advances in the capabilities of diagnostic imaging. Core techniques have focused on the assessment of vessel caliber, tissue metabolism, and/or regional perfusion parameters. Advances in imaging have provided clinicians with a multifaceted approach to assist in the detection of cerebral vasospasm and the diagnosis...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-15

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  4. Ventilation-perfusion imaging in pulmonary papillomatosis

    International Nuclear Information System (INIS)

    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

  5. Cerebral imaging in pediatrics

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, I. [London, Great Ormond Street Hospital for Children (United Kingdom)

    1998-06-01

    Radioisotope brain imaging has focused mainly on regional cerebral blood flow (rCBF). However the use of ligand which go to specific receptor sites is being introduced in pediatrics, mainly psychiatry. rCBF is potentially available in many institutions, especially with the availability of multi-headed gamma cameras. The use of this technique in pediatrics requires special attention to detail in the manner of data acquisition and handling the child. The interpretation of the rCBF study in a child requires knowledge of normal brain maturation. The major clinical use in pediatrics is epilepsy because of the advances in surgery and the frequency of complex partial seizures. Other indications in pediatric neurology include brain death, acute neurological loss including stroke, language disorders, cerebral palsy, hypertension due to renovascular disease, traumatic brain injury and migraine. There are pediatric physiological conditions in which rCBF has been undertaken, these include anorexia nervosa, autism, Gilles de la Tourette syndrome (GTS) and attention deficit disorder-hyperactivity (ADHD). Research using different ligands to specific receptor sites will also be reviewed in pediatrics.

  6. Cerebral imaging in pediatrics

    International Nuclear Information System (INIS)

    Radioisotope brain imaging has focused mainly on regional cerebral blood flow (rCBF). However the use of ligand which go to specific receptor sites is being introduced in pediatrics, mainly psychiatry. rCBF is potentially available in many institutions, especially with the availability of multi-headed gamma cameras. The use of this technique in pediatrics requires special attention to detail in the manner of data acquisition and handling the child. The interpretation of the rCBF study in a child requires knowledge of normal brain maturation. The major clinical use in pediatrics is epilepsy because of the advances in surgery and the frequency of complex partial seizures. Other indications in pediatric neurology include brain death, acute neurological loss including stroke, language disorders, cerebral palsy, hypertension due to renovascular disease, traumatic brain injury and migraine. There are pediatric physiological conditions in which rCBF has been undertaken, these include anorexia nervosa, autism, Gilles de la Tourette syndrome (GTS) and attention deficit disorder-hyperactivity (ADHD). Research using different ligands to specific receptor sites will also be reviewed in pediatrics

  7. Perfusion magnetic resonance imaging of the liver

    Institute of Scientific and Technical Information of China (English)

    Choon; Hua; Thng; Tong; San; Koh; David; J; Collins; Dow; Mu; Koh

    2010-01-01

    Perfusion magnetic resonance imaging (MRI) studies quantify the microcirculatory status of liver parenchyma and liver lesions, and can be used for the detection of liver metastases, assessing the effectiveness of antiangiogenic therapy, evaluating tumor viability after anticancer therapy or ablation, and diagnosis of liver cirrhosis and its severity. In this review, we discuss the basic concepts of perfusion MRI using tracer kinetic modeling, the common kinetic models applied for analyses, the MR scanning t...

  8. Measurement of radiation dose in cerebral CT perfusion study

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-01-15

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

  10. Brain imaging with radiolabeled amines and other perfusion tracers

    International Nuclear Information System (INIS)

    This paper discusses how emission CT with radiolabeled amines is useful in a number of circumstances. In acute cerebral infarction, the CT scan may be normal for several days after onset of symptoms, whereas the uptake of radiolabeled amines will be altered immediately after the onset of the stroke. Even when the CT scan has become abnormal, the physiologic abnormality may exceed the anatomic abnormality. We may therefore be able to measure the extent of the reversibly ischemic tissue early enough to justify more aggressive therapeutic interventions. Medical and surgical therapies, such as endarterectomy, have been without readily available objective methods to assess their efficacy. Serial measurements of regional cerebral perfusion with radiolabeled amines may provide such a tool. Of equal importance, SPECT imaging with I-123-labeled amines provides a useful screening test to determine which patients with carotid stenosis should be approached first. Iodine-123 IMP imaging may become the method of choice for the diagnosis and evaluation of Alzheimer's disease

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-01-01

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

  13. Comparative study of cerebral blood perfusion SPECT imaging and CT scan in evaluation of the curative effect of hyperbaric oxygen in patients with post-traumatic brain syndrome

    International Nuclear Information System (INIS)

    Objective: To comparatively study the results of cerebral SPECT and cerebral CT before and after hyperbaric oxygen (HBO) treatment in post-traumatic brain syndrome. Methods: HBO was used to treat 288 patients with post-traumatic brain syndrome for two courses, and made therapeutic surveillance and comparative analysis with 99Tcm-ECD SPECT, CT before and after treatment. Results: Before treatment, the positive rate of cerebral SPECT was 80.6%, but the positive rate of CT was only 10.2%; after treatment, 90% of SPECT became negative, and the clinical symptoms of the patients disappeared as SPECT became negative. The results showed that HBO treatment could evidently improve rCBF, and showed that SPECT was superior to CT in surveillance of HBO treatment. Conclusions: 99Tcm-ECD SPECT could play an important role in the diagnosis of post-traumatic brain syndrome and the therapeutic surveillance of HBO

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

    Science.gov (United States)

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

    2014-04-01

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

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

    OpenAIRE

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  17. MR Spectroscopy and Perfusion MR Imaging Findings of Intracranial Foreign Body Granuloma: a Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seung Won; Kim, Sang Joon; Kim, Sun Mi; Lee, Jeong Hyun; Choi, Choong Gon; Lee, Deok Hee; Lee, Jung Kyo [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Kim, Eun Ju [Philips Healthcare, Seoul (Korea, Republic of)

    2010-06-15

    We report a case of intracranial foreign body granuloma that showed features of a high grade tumor on magnetic resonance (MR) imaging. However, the relative cerebral blood volume was not increased in the enhancing mass on perfusion MRI and the choline/creatine ratio only slightly increased on MR spectroscopy. The results suggest that the lesion is benign in nature. Perfusion MRI and MR spectroscopy may be helpful to differentiate a foreign body granuloma from a neoplastic condition

  18. MR Spectroscopy and Perfusion MR Imaging Findings of Intracranial Foreign Body Granuloma: a Case Report

    International Nuclear Information System (INIS)

    We report a case of intracranial foreign body granuloma that showed features of a high grade tumor on magnetic resonance (MR) imaging. However, the relative cerebral blood volume was not increased in the enhancing mass on perfusion MRI and the choline/creatine ratio only slightly increased on MR spectroscopy. The results suggest that the lesion is benign in nature. Perfusion MRI and MR spectroscopy may be helpful to differentiate a foreign body granuloma from a neoplastic condition

  19. MR Spectroscopy and Perfusion MR Imaging Findings of Intracranial Foreign Body Granuloma: a Case Report

    OpenAIRE

    Jang, Seung Won; Kim, Sang Joon; Kim, Sun Mi; Lee, Jeong Hyun; Choi, Choong Gon; Lee, Deok Hee; Kim, Eun Ju; Lee, Jung-Kyo

    2010-01-01

    We report a case of intracranial foreign body granuloma that showed features of a high grade tumor on magnetic resonance (MR) imaging. However, the relative cerebral blood volume was not increased in the enhancing mass on perfusion MRI and the choline/creatine ratio only slightly increased on MR spectroscopy. The results suggest that the lesion is benign in nature. Perfusion MRI and MR spectroscopy may be helpful to differentiate a foreign body granuloma from a neoplastic condition.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-02-15

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

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

    International Nuclear Information System (INIS)

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

  2. Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

    International Nuclear Information System (INIS)

    The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries. (orig.)

  3. Fractal analysis in radiological and nuclear medicine perfusion imaging: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Michallek, Florian; Dewey, Marc [Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Charite - Universitaetsmedizin Berlin, Medical School, Department of Radiology, Berlin (Germany)

    2014-01-15

    To provide an overview of recent research in fractal analysis of tissue perfusion imaging, using standard radiological and nuclear medicine imaging techniques including computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) and to discuss implications for different fields of application. A systematic review of fractal analysis for tissue perfusion imaging was performed by searching the databases MEDLINE (via PubMed), EMBASE (via Ovid) and ISI Web of Science. Thirty-seven eligible studies were identified. Fractal analysis was performed on perfusion imaging of tumours, lung, myocardium, kidney, skeletal muscle and cerebral diseases. Clinically, different aspects of tumour perfusion and cerebral diseases were successfully evaluated including detection and classification. In physiological settings, it was shown that perfusion under different conditions and in various organs can be properly described using fractal analysis. Fractal analysis is a suitable method for quantifying heterogeneity from radiological and nuclear medicine perfusion images under a variety of conditions and in different organs. Further research is required to exploit physiologically proven fractal behaviour in the clinical setting. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

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

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  8. Arterial spin-labeling MR imaging of cerebral hemorrhages

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Tomoyuki [Department of Radiology, National Center for Global Health and Medicine, Tokyo (Japan); Saga University, Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga (Japan); Nishihara, Masashi; Egashira, Yoshiaki; Azama, Shinya; Hirai, Tetsuyoshi; Kitano, Isao; Irie, Hiroyuki [Saga University, Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga (Japan); Yakushiji, Yusuke [Saga University, Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Saga (Japan); Kawashima, Masatou [Saga University, Department of Neurosurgery, Faculty of Medicine and Graduate School of Medicine, Saga (Japan)

    2015-11-15

    The purpose of this study is to identify the characteristics of brain perfusion measured by arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cerebral hemorrhages. Brain blood flow values (CBF-ASL values) for cerebral and cerebellar hemispheres and segmented cerebral regions were measured by ASL-MRI in 19 putaminal hemorrhage patients and 20 thalamic hemorrhage patients in acute or subacute stages. We assessed the lateralities of CBF-ASL values and the relationships between CBF-ASL values and other imaging findings and clinical manifestations. Both the 19 putaminal hemorrhage patients and the 20 thalamic hemorrhage patients had significantly low CBF-ASL values of the contralateral cerebellum in subacute stage, suggesting that ASL-MRI might delineate crossed cerebellar diaschisis (CCD). Ipsilateral low CBF-ASL values were observed in frontal lobes and thalami with a putaminal hemorrhage and lentiform nuclei, temporal lobes, and parietal lobes with a thalamic hemorrhage, suggesting that ASL-MRI showed the ipsilateral cerebral diaschisis (ICD). In the putaminal hemorrhage patients, the hematoma volume negatively affected both the bilateral cerebellar and cerebral hemispheric CBF-ASL values. In the thalamic hemorrhage patients, a concomitant intraventricular hemorrhage caused low cerebral hemispheric CBF-ASL values. The use of ASL-MRI is sensitive to the perfusion abnormalities and could thus be helpful to estimate functional abnormalities in cerebral hemorrhage patients. (orig.)

  9. Clinical value of dipyridamole brain perfusion imaging in the diagnosis of ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Using dipyridamole stress test to evaluate cerebral blood flow reserve in cerebrovascular disease (CVD). Dipyridamole stress tests were performed first, the baseline SPECT images were obtained under similar conditions 2-5 days later. By visual and semiquantitative analysis, the responses of cerebral blood flow to dipyridamole were divided into the following four patterns: A: The dipyridamole SPECT showed an expanded area of hypoperfusion, Asymmetry Index(AI) and Uptake Rate(UR) were all decreased; B: Rest images was normal but new hypoperfused areas appeared on stress test with decreased Al and UR; C: Hypoperfused areas were decreased in size or disappeared after stress test with increased Al and UR; D: No changes showed in cerebral perfusion imaging patterns, and in Al and UR between stress and rest studies. Dipyridarnole brain perfusion imaging may be helpful to the diagnosis of CVD, to the decision the therapeutic plan, and to predicting the therapeutic effect.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Astudillo Ley, Rafael

    1998-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  15. Brain perfusion imaging in amyotrophic lateral sclerosis with dementia

    International Nuclear Information System (INIS)

    Single photon emission computed tomography (SPECT) studies have been applied for evaluation of regional cerebral blood flow (rCBF) in various neurodegenerative disorders including amyotrophic lateral sclerosis (ALS) and ALS with dementia (ALS-D). Brain perfusion SPECT using statistical image analysis is useful for accurate and objective diagnosis to evaluate slight decreases in rCBF, even in cases difficult to assess by visual inspection. We have used statistical parametric mapping (SPM), three-dimensional stereotactic surface projection (3D-SSP), easy Z-score imaging system (eZIS) as statistical image analyses. ALS-D cases, even if a case manifests minimal mentality change, showed obvious rCBF reduction in the bilateral prefrontal area with some irregularity and laterality of its decrease. This abnormality was clear in ALS-D compared with classic ALS. Our study has demonstrated that brain perfusion SPECT imaging using statistical image analyses is quite useful as an adjunct to presume the existence of dementia in ALS, even if ALS patients have trouble in verbal or manual communication of the language because of progressive bulbar symptoms and muscle weakness. Thus, for ALS patients with any subtle signs and symptoms suggesting dementia, we recommend a SPECT study with use of statistical image analyses. (author)

  16. New imaging techniques in myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Gated myocardial SPECT and attenuation correction gave birth to new insights into the pathophysiology of ischemic myocardial perfusion and function in clinical routine practice. Gated myocardial Tc-99m-compound SPECT improved diagnostic accuracy of coronary artery disease and enabled us to observe motion and thickening of myocardial walls as well as myocardial perfusion at the same time. Quantitative and qualitative assessment of myocardial performance and perfusion let us to understand the myocardial physiology in ischemia and infarction. In every patient who underwent gated perfusion SPECT, we will find ejection fraction, left ventricular volumes and regional wall motion. There are hopes to use gated Tl-201 SPECT for the same purpose and to use gated SPECT for evaluation of wall motion and thickening at stress or immediate post-stress. Attenuation correction could improve diagnostic accuracy mainly by increasing normalcy ratio or performance of non-expert physicians Both gated methods and attenuation correction improved specificity of non-expert physicians in diagnosing patients with moderate pretest likelihood. New imaging techniques will fill the desire of cardiologists to examine function and perfusion, and possibly metabolism in their clinical routine practice

  17. Perfusion weighted imaging and its application in stroke

    Science.gov (United States)

    Li, Enzhong; Tian, Jie; Han, Ying; Wang, Huifang; Li, Xingfeng; Zhu, Fuping

    2003-05-01

    To study the technique and application of perfusion weighted imaging (PWI) in the diagnosis and medical treatment of acute stroke, 25 patients were examined by 1.5 T or 1.0 T MRI scanner. The Data analysis was done with "3D Med System" developed by our Lab to process the data and obtain apparent diffusion coefficient (ADC) map, cerebral blood volume (CBV) map, cerebral blood flow (CBF) map as well as mean transit time (MTT) map. In accute stage of stroke, normal or slightly hypointensity in T1-, hyperintensity in T2- and diffusion-weighted images were seen in the cerebral infarction areas. There were hypointensity in CBV map, CBF map and ADC map; and hyperintensity in MTT map that means this infarct area could be saved. If the hyperintensity area in MTT map was larger than the area in diffusion weighted imaging (DWI), the larger part was called penumbra and could be cured by an appropriate thrombolyitic or other therapy. The CBV, CBF and MTT maps are very important in the diagnosis and medical treatment of acute especially hyperacute stroke. Comparing with DWI, we can easily know the situation of penumbra and the effect of curvative therapy. Besides, we can also make a differential diagnosis with this method.

  18. Magnetic Resonance Perfusion Imaging in Malformations of Cortical Development

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-15

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

  19. Advanced imaging modalities in the detection of cerebral vasospasm.

    Science.gov (United States)

    Mills, Jena N; Mehta, Vivek; Russin, Jonathan; Amar, Arun P; Rajamohan, Anandh; Mack, William J

    2013-01-01

    The pathophysiology of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is complex and is not entirely understood. Mechanistic insights have been gained through advances in the capabilities of diagnostic imaging. Core techniques have focused on the assessment of vessel caliber, tissue metabolism, and/or regional perfusion parameters. Advances in imaging have provided clinicians with a multifaceted approach to assist in the detection of cerebral vasospasm and the diagnosis of delayed ischemic neurologic deficits (DIND). However, a single test or algorithm with broad efficacy remains elusive. This paper examines both anatomical and physiological imaging modalities applicable to post-SAH vasospasm and offers a historical background. We consider cerebral blood flow velocities measured by Transcranial Doppler Ultrasonography (TCD). Structural imaging techniques, including catheter-based Digital Subtraction Angiography (DSA), CT Angiography (CTA), and MR Angiography (MRA), are reviewed. We examine physiologic assessment by PET, HMPAO SPECT, (133)Xe Clearance, Xenon-Enhanced CT (Xe/CT), Perfusion CT (PCT), and Diffusion-Weighted/MR Perfusion Imaging. Comparative advantages and limitations are discussed. PMID:23476766

  20. Advanced Imaging Modalities in the Detection of Cerebral Vasospasm

    Directory of Open Access Journals (Sweden)

    Jena N. Mills

    2013-01-01

    Full Text Available The pathophysiology of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH is complex and is not entirely understood. Mechanistic insights have been gained through advances in the capabilities of diagnostic imaging. Core techniques have focused on the assessment of vessel caliber, tissue metabolism, and/or regional perfusion parameters. Advances in imaging have provided clinicians with a multifaceted approach to assist in the detection of cerebral vasospasm and the diagnosis of delayed ischemic neurologic deficits (DIND. However, a single test or algorithm with broad efficacy remains elusive. This paper examines both anatomical and physiological imaging modalities applicable to post-SAH vasospasm and offers a historical background. We consider cerebral blood flow velocities measured by Transcranial Doppler Ultrasonography (TCD. Structural imaging techniques, including catheter-based Digital Subtraction Angiography (DSA, CT Angiography (CTA, and MR Angiography (MRA, are reviewed. We examine physiologic assessment by PET, HMPAO SPECT, 133Xe Clearance, Xenon-Enhanced CT (Xe/CT, Perfusion CT (PCT, and Diffusion-Weighted/MR Perfusion Imaging. Comparative advantages and limitations are discussed.

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

    Science.gov (United States)

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

    2009-07-01

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

  2. Speckles in laser Doppler perfusion imaging

    OpenAIRE

    Rajan, V; Varghese, B.; Leeuwen, van; W. Steenbergen

    2006-01-01

    We report on the quantitative influence of speckles in laser Doppler perfusion imaging. The influence of speckles on the signal amplitude and on the Doppler spectrum is demonstrated experimentally for particle suspensions with different scattering levels and various beam widths. It is shown that the type of tissue affects the instrumental response through the effect of lateral light diffusion on the number of speckles involved in the detection process. These effects are largest for narrow beams.

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

    International Nuclear Information System (INIS)

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

  4. Noise characteristics of CT perfusion imaging: how does noise propagate from source images to final perfusion maps?

    Science.gov (United States)

    Li, Ke; Chen, Guang-Hong

    2016-03-01

    Cerebral CT perfusion (CTP) imaging is playing an important role in the diagnosis and treatment of acute ischemic strokes. Meanwhile, the reliability of CTP-based ischemic lesion detection has been challenged due to the noisy appearance and low signal-to-noise ratio of CTP maps. To reduce noise and improve image quality, a rigorous study on the noise transfer properties of CTP systems is highly desirable to provide the needed scientific guidance. This paper concerns how noise in the CTP source images propagates to the final CTP maps. Both theoretical deviations and subsequent validation experiments demonstrated that, the noise level of background frames plays a dominant role in the noise of the cerebral blood volume (CBV) maps. This is in direct contradiction with the general belief that noise of non-background image frames is of greater importance in CTP imaging. The study found that when radiation doses delivered to the background frames and to all non-background frames are equal, lowest noise variance is achieved in the final CBV maps. This novel equality condition provides a practical means to optimize radiation dose delivery in CTP data acquisition: radiation exposures should be modulated between background frames and non-background frames so that the above equality condition is satisïnAed. For several typical CTP acquisition protocols, numerical simulations and in vivo canine experiment demonstrated that noise of CBV can be effectively reduced using the proposed exposure modulation method.

  5. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

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

    1994-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  8. MR imaging of cerebral palsy

    Energy Technology Data Exchange (ETDEWEB)

    Saginoya, Toshiyuki [Urasoe General Hospital, Okinawa (Japan); Yamaguchi, Keiichiro; Kuniyoshi, Kazuhide [and others

    1996-06-01

    We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n=11), spastic diplegia (n=9), spastic hemiplegia (n=2), double hemiplegia (n=1), athetosis (n=10) and mixed (n=2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease. (author)

  9. Cerebral imaging revealing Alzheimer's disease

    International Nuclear Information System (INIS)

    Cerebral imaging is the only non-invasive means of examining the brain and is essential in studying Alzheimer's disease. As a tool for early diagnosis, evaluation and treatment monitoring, this technology is at the heart of the research being done to further improve its reliability and sensitivity. (authors)

  10. MR imaging of cerebral palsy

    International Nuclear Information System (INIS)

    We evaluated 35 patients with cerebral palsy on the basis of MR imaging findings in the brain. The types of palsy were spastic quadriplegia (n=11), spastic diplegia (n=9), spastic hemiplegia (n=2), double hemiplegia (n=1), athetosis (n=10) and mixed (n=2). Of all patients, 28 (80%) generated abnormal findings. In spastic quadriplegia, although eight cases revealed severe brain damage, two cases showed no abnormal findings in the brain. One of the three had cervical cord compression caused by atlanto-axial subluxation. In spastic diplegia, the findings were divided according to whether the patient was born at term or preterm. If the patient had been born prematurely, the findings showed periventricular leukomalacia and abnormally high intensity in the posterior limbs of the internal capsule on T2-weighted images. MR imaging in spastic hemiplegia revealed cerebral infarction. In the athetoid type, half of all cases showed either no abnormal findings or slight widening of the lateral ventricle. Three cases showed abnormal signals of the basal ganglia. The reason why athetoid-type palsy did not show severe abnormality is unknown. We believe that MR imaging is a useful diagnostic modality to detect damage in the brain in cerebral palsy and plays an important role in the differentiation of cerebral palsy from the spastic palsy disease. (author)

  11. Perfusion computed tomography imaging of autoimmune pancreatitis

    International Nuclear Information System (INIS)

    Perfusion computed tomography (P-CT) is now available for the analysis of pancreatic blood flow. The aim of this study was to clarify pancreatic blood perfusion in AIP patients and the changes after steroid treatment. Color map imaging of P-CT and pancreatic time CT density curve (TDC) demonstrated that the pancreatic blood flow was attenuated in AIP patients. Pancreatic volumetric blood flow FV values of 11 AIP patients (82.7/min) were significantly lower than those of 12 normal controls (163.5/min, p=0.0006). AIP patients received steroid treatment and were re-examined, of these, 9 patients showed significantly elevated FV values after treatment (76.2/min and 109.8/min, p=0.0391, respectively). However, the changes of the values after the treatment differed in varying degrees among the individuals. P-CT is a useful method for the analysis of the blood flow in pancreatic diseases. (author)

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

    OpenAIRE

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

    2015-01-01

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

  13. Detection of myocardial perfusion defect with 320-row volume CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility of 320-row volume CT myocardial perfusion imaging (CT-MPI) in detecting myocardial perfusion defect. Methods: Fourteen patients with positive single-positron emission computed tomography myocardial perfusion imaging (SPECT-MPI) findings underwent both rest and adenosine stress 320-row volume CT-MPI. Rest and stress CT perfusion images were analyzed by employing dedicated software in 320-row CT workstation. Both SPECT-MPI and CT-MPI were evaluated for fixed and reversible perfusion defects using a 16-segment model (apex was excluded). The sensitivity, specificity of 320-row volume CT-MPI in detecting myocardial perfusion defect were evaluated by taking SPECT-MPI as a reference standard. Results: Both rest and stress 320-row volume CT-MPI were successfully performed in all patients. Thirty nine segments with fixed or reversible perfusion defects in all patients were depicted by SPECT-MPI, while 34 perfusion defects in 12 patients were identified by CT-MPI. The sensitivity, specificity of 320-row volume CT-MPI for detection of perfusion defects were 87.2%(34/39), 91.4% (169/185), respectively. Conclusion: 320-row volume CT-MPI has high sensitivity and specificity for detection of myocardial perfusion defects. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-01

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

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

    International Nuclear Information System (INIS)

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

  16. Preliminary application of brain perfusion SPECT imaging in schizophrenia

    International Nuclear Information System (INIS)

    The clinical value of 99mTc-ECD brain perfusion SPECT imaging was evaluated in patients with schizophrenia. 32 patients with schizophrenia and 21 normal controls were analyzed with 99mTc-ECD SPECT. 93.8% (30/32) of the patients showed decreased regional cerebral blood flow (rCBF). There was normal rCBF in controls. In the patient group rCBF decreased significantly in bilateral frontal lobes, left temporal lobe and right basal ganglion. The rCBF of left temporal lobe was significantly lower than that of right temporal lobe. The decreasing rCBF was not significantly related to previous treatment and duration of illness. 99mTc-ECD SPECT is useful for the study and diagnosis of patients with schizophrenia

  17. Pitfalls and Artifacts in Myocardial Perfusion Imaging

    International Nuclear Information System (INIS)

    Myocardial perfusion imaging (MPI) is an important modality in the management of patients with cardiovascular disease. It is useful for the diagnosis of cardiovascular disease, prognosis and evaluating viability. Although MPI is a valuable diagnostic modality, it is subject to several potential problems. These problems are the technical factors that alter the representation of the structures or displace it in the field of view. Technologists must be conscious of these pitfalls and artifacts as successful image interpretations depend on the prevention, recognition and correction of these problems. These technical issues are patient, equipment QC and processing related. Physiological patient related artifacts can be seen in cases of left bundle branch block, left ventricular hypertrophy, dextrocardia and heart valve disorders. Also incidental findings such as malignant tumor and pericardial effusion must be considered. Inappropriate patient preparation regarding fasting status, medications and adequacy of exercise are very critical in this imaging process. The attenuating structures between the heart and the detector cause apparent artifacts and this maybe the result of breast tissue or prosthesis, diaphragm, arm and adipose of the lateral chest wall. Patient motion is the most common artifacts leading to false positive readings and can be classified into vertical, horizontal and rotational movements. Generation of sinogram and linogram helps in the detection of movements. The presence of splanchnic activity as a normal excretory route for perfusion radiopharmaceuticals may lead to two problems: it obscures any defect in the inferior wall as a result of scatter and it may causes reduction in the activity in adjacent cardiac segments. An adequate amount of time between injection of the radiopharmaceutical and imaging is required to allow the clearance of this activity. Perfusion defects can also be artifactually created because of poor counting statistics as a result

  18. Radionuclide imaging of perfusion and hypoxia

    International Nuclear Information System (INIS)

    We present a review of radionuclide imaging of tumour vascular physiology as it relates to angiogenesis. We focus on clinical trials in human subjects using PET and SPECT to evaluate tumour physiology, in particular blood flow and hypoxia. A systematic review of literature based on MEDLINE searches updated in February 2010 was performed. Twenty-nine studies were identified for review: 14 dealt with 15O-water PET perfusion imaging, while 8 dealt with 18F-fluoromisonidazole PET hypoxia imaging. Five used SPECT methods. The studies varied widely in technical quality and reporting of methods. A subset of radionuclide methods offers accurate quantitative scientific observations on tumour vascular physiology of relevance to angiogenesis and its treatment. The relationship between cellular processes of angiogenesis and changing physiological function remains poorly defined. The promise of quantitative functional imaging at high specificity and low administered dose sustains interest in radionuclide methods. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Euclides Timóteo da Rocha

    2011-01-01

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

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

    NARCIS (Netherlands)

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

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hakimelahi Reza

    2012-11-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-15

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

  5. Cerebral imaging and dementia

    Energy Technology Data Exchange (ETDEWEB)

    Rascol, A.; Celsis, P.; Berry, I.

    1989-02-01

    Modern imaging techniques undoubtedly are of value when applied to the study of dementia. This value, however, varies with the technique utilized, and one must distinguish between acquired and potential knowledge. Morphological imaging with computerized tomography or magnetic resonance detects or confirms certain causes of dementia (tumours, lacunae, hydrocephalus with normal CSF pressure), but it is still not sensitive and specific enough to be very useful in primary dementias. Functional imaging (essentially with emission tomography) has already provided interesting data in the study of degenerative dementia (correlations with neuropsychology, subtyping), but what is most promising is its possibilities in the physiopathological approach of the disease.

  6. Cerebral imaging and dementia

    International Nuclear Information System (INIS)

    Modern imaging techniques undoubtedly are of value when applied to the study of dementia. This value, however, varies with the technique utilized, and one must distinguish between acquired and potential knowledge. Morphological imaging with computerized tomography or magnetic resonance detects or confirms certain causes of dementia (tumours, lacunae, hydrocephalus with normal CSF pressure), but it is still not sensitive and specific enough to be very useful in primary dementias. Functional imaging (essentially with emission tomography) has already provided interesting data in the study of degenerative dementia (correlations with neuropsychology, subtyping), but what is most promising is its possibilities in the physiopathological approach of the disease

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

    International Nuclear Information System (INIS)

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

  8. Imaging of ventilation/perfusion ratio by gated regional spirometry

    International Nuclear Information System (INIS)

    Gated 133Xe images of patients rebreathing into a closed system can provide images of the distribution of lung volumes, ventilation and specific ventilation. These have been shown to be accurate, precise, and do not require unusually sophisticated equipment or skills. A mathematical transformation is used to correct the images for lung movement, which does not alter the total number of counts in the image. Perfusion images are gated to remove motion blurring but not transformed. Ventilation/perfusion images showing the distribution of V/Q ratio are then generated from the individual ventilation and perfusion images. (author)

  9. Ventilation and perfusion display in a single image

    International Nuclear Information System (INIS)

    A new method of ventilation and perfusion display onto a single image is presented. From the data on regions of interest of the lungs, three-dimensional histograms are created, containing as parameters X and Y for the position of the pixels, Z for the perfusion and colour for local ventilation. The perfusion value is supplied by sets of curves having Z proportional to the local perfusion count rate. Ventilation modulates colour. Four perspective views of the histogram are simultaneously displayed to allow visualization of the entire organ. Information about the normal ranges for both ventilation and perfusion is also provided in the histograms. (orig.)

  10. Diffusion and perfusion imaging of bone marrow

    Energy Technology Data Exchange (ETDEWEB)

    Biffar, Andreas; Dietrich, Olaf [Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, LMU University Hospitals, Grosshadern-Munich (Germany); Sourbron, Steven [Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, LMU University Hospitals, Grosshadern-Munich (Germany); Division of Medical Physics, University of Leeds, Leeds (United Kingdom); Duerr, Hans-Roland [Department of Orthopedic Surgery, LMU University Hospitals, Grosshadern-Munich (Germany); Reiser, Maximilian F. [Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, LMU University Hospitals, Grosshadern-Munich (Germany); Department of Clinical Radiology, LMU University Hospitals, Grosshadern-Munich (Germany); Baur-Melnyk, Andrea, E-mail: andrea.baur@med.uni-muenchen.de [Department of Clinical Radiology, LMU University Hospitals, Grosshadern-Munich (Germany)

    2010-12-15

    In diffusion-weighted magnetic resonance imaging (DWI), the observed MRI signal intensity is attenuated by the self-diffusion of water molecules. DWI provides information about the microscopic structure and organization of a biological tissue, since the extent and orientation of molecular motion is influenced by these tissue properties. The most common method to measure perfusion in the body using MRI is T1-weighted dynamic contrast enhancement (DCE-MRI). The analysis of DCE-MRI data allows determining the perfusion and permeability of a biological tissue. DWI as well as DCE-MRI are established techniques in MRI of the brain, while significantly fewer studies have been published in body imaging. In recent years, both techniques have been applied successfully in healthy bone marrow as well as for the characterization of bone marrow alterations or lesions; e.g., DWI has been used in particular for the differentiation of benign and malignant vertebral compression fractures. In this review article, firstly a short introduction to diffusion-weighted and dynamic contrast-enhanced MRI is given. Non-quantitative and quantitative approaches for the analysis of DWI and semiquantitative and quantitative approaches for the analysis of DCE-MRI are introduced. Afterwards a detailed overview of the results of both techniques in healthy bone marrow and their applications for the diagnosis of various bone-marrow pathologies, like osteoporosis, bone tumors, and vertebral compression fractures are described.

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

    OpenAIRE

    Feng, Qi; Chen, Xue; Sun, Jinhua; Zhou, Yan; Sun, Yawen; Ding, Weina; Zhang, Yong; Zhuang, Zhiguo; Xu, Jianrong; Du, Yasong

    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 adolescen...

  12. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    Science.gov (United States)

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

    2015-11-01

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

  13. The clinical evaluation of Nimodipine treatment by SPECT brain perfusion imaging

    International Nuclear Information System (INIS)

    PURPOSE: Clinical evaluation of patients with cerebropathy by SPECT brain perfusion imaging before and after Nimodipine treatment were studied. METHODS: 53 patients were divided into 3 groups: 26 migraine (interictal), 19 cerebral ischemia (11 TIA and 8 cerebral infarction) and 8 brain trauma. SPECT brain perfusion imaging was performed before and after Nimodipine treatment, and quantitative analysis was processed with normal/focus mirror regions ratio on transverse images. RESULTS: Before Nimodipine administration, the focal defects with various magnitude were showed by SPECT, and after treatment with Nimodipine, the original focal defects were filled in varying degree. The rate of significant filling, filling, total filling and non-filling were 27.3%, 57.5%, 84.8% and 15.2% respectively in migraine, 64.3%, 28.5%, 92.8% and 7.2% respectively in TIA and 20%, 60%, 80% and 20% respectively in cerebral infarction, whereas in brain traumas, filling rate was 100%. CONCLUSION: Most patients have various improvement of the focal defect after Nimodipine treatment. Therefore, SPECT brain perfusion imaging can be used to observe and evaluate the therapeutic effects of Nimodipine

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

    Science.gov (United States)

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

    2016-01-01

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

  15. MR perfusion imaging study of the hepatic hemodynamics in pigs

    International Nuclear Information System (INIS)

    Objective: To evaluate the MR perfusion imaging in measuring the hemodynamics of liver. Methods: CT and MR perfusion imaging were performed in livers of 13 pigs. The hepatic artery perfusion (HAP), portal vein perfusion (PVP), total hepatic blood flow (THBF), portal vein perfusion index (PVI), distribution volume (DV) and mean transit time (MTT) were calculated and compared respectively. Hemodynamics of the liver from two kinds of imaging was compared by paired t-test, and the relativity was analyzed by Pearson correlation analysis. Results: In CT and MR perfusion imaging of the 13 pigs: the hepatic artery perfusion (HAP) were (37.71±7.38) and (35.80±7.31) ml·min-1 100 ml-1, the portal vein perfusion (PVP) were (123.16±35.89) and (121.40±36.81) ml·min-1· 100 ml-1, the total hepatic blood flow (THBF) were (160.88±37.05) and (157.21±38.71) ml·min-1 ·100 ml-1, the portal vein perfusion index (PVI) were (75.95±5.21)% and (76.63±5.24)%, the distribution volume (DV) were (35.10±11.17)% and (41.03±10.06)%, the mean transit time (MTT) were (14.08±1.40) and (14.94±1.32) s. There were no statistical diferences for HAP, PVP, THBF and PVI between CT and Mil perfusion imaging (t=1.263, 0.926, 1.225, -1.115, P>0.05). There were no statistical differences for DV and MTT (t=-3.345, -3.200, P0.85, P0.70, P<0.01). Conclusions: MR perfusion can quantify the blood flow parameters of liver accurately. It is close to that of the CT perfusion imaging. (authors)

  16. Myocardial Perfusion Spect Imaging in Dextrocardia: A Case Report

    Directory of Open Access Journals (Sweden)

    Semra Özdemir

    2013-08-01

    Full Text Available The myocardial perfusion scintigraphy acquisition and analysis present some technical differences in the rare dextrocardia cases. Here we report a case of a 38 year-old woman with dextrocardia who had been applied myocardial perfusion scintigraphy. Presented case showed that the thoracic and abdominal organs had a mirror image with situs inversus totalis type dextrocardia. The incidence of coronary heart disease and life span of people with situs inversus totalis are the same as the normal population. So we may apply myocardial perfusion scintigraphy to this patient group. The current case is presented in order to remind the special applications of myocardial perfusion SPECT imaging in patients with dextrocardia.

  17. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orrison, W.W. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Department of Medical Education, University of Nevada School of Medicine, Reno, NV (United States); Snyder, K.V.; Hopkins, L.N. [Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Buffalo, NY (United States); Roach, C.J. [School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Ringdahl, E.N. [Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV (United States); Nazir, R. [Shifa International Hospital, Islamabad (Pakistan); Hanson, E.H., E-mail: eric.hanson@amigenics.co [College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States)

    2011-06-15

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

  18. Whole-brain dynamic CT angiography and perfusion imaging

    International Nuclear Information System (INIS)

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  20. Monitoring cerebral perfusion after subarachnoid hemorrhage using CT

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    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

  4. Brain perfusion spect imaging with 99mTc-HM-PAO in Parkinson's disease

    International Nuclear Information System (INIS)

    Forty patients with Parkinson's disease were studied using 99mTc-HM-PAO brain perfusion SPECT. 62.5% (25 cases) showed abnormal blood perfusion. Among them 55% showed local decreased blood perfusion of cerebral cortex, 22% showed asymmetric decreased blood perfusion in basal gaglia, 10% showed decreased uptake of tracer in cerebellum. The pathophysiologic basis of the abnormality of brain blood perfusion were briefly discussed

  5. Pulmonary ventilation and perfusion imaging with dual-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Thieme, Sven F. [Klinikum Grosshadern, Department of Clinical Radiology, Ludwig Maximilians University, Muenchen (Germany); Klinikum Grosshadern, Institut fuer Klinische Radiologie, LMU Muenchen, Muenchen (Germany); Hoegl, Sandra; Fisahn, Juergen; Irlbeck, Michael [Klinikum Grosshadern, Department of Anesthesiology, Ludwig Maximilians University, Muenchen (Germany); Nikolaou, Konstantin; Maxien, Daniel; Reiser, Maximilian F.; Becker, Christoph R.; Johnson, Thorsten R.C. [Klinikum Grosshadern, Department of Clinical Radiology, Ludwig Maximilians University, Muenchen (Germany)

    2010-12-15

    To evaluate the feasibility of dual-energy CT (DECT) ventilation imaging in combination with DE perfusion mapping for a comprehensive assessment of ventilation, perfusion, morphology and structure of the pulmonary parenchyma. Two dual-energy CT acquisitions for xenon-enhanced ventilation and iodine-enhanced perfusion mapping were performed in patients under artificial respiration. Parenchymal xenon and iodine distribution were mapped and correlated with structural or vascular abnormalities. In all datasets, image quality was sufficient for a comprehensive image reading of the pulmonary CTA images, lung window images and pulmonary functional parameter maps and led to expedient results in each patient. With dual-source CT systems, DECT of the lung with iodine or xenon administration is technically feasible and makes it possible to depict the regional iodine or xenon distribution representing the local perfusion and ventilation. (orig.)

  6. Pulmonary ventilation and perfusion imaging with dual-energy CT

    International Nuclear Information System (INIS)

    To evaluate the feasibility of dual-energy CT (DECT) ventilation imaging in combination with DE perfusion mapping for a comprehensive assessment of ventilation, perfusion, morphology and structure of the pulmonary parenchyma. Two dual-energy CT acquisitions for xenon-enhanced ventilation and iodine-enhanced perfusion mapping were performed in patients under artificial respiration. Parenchymal xenon and iodine distribution were mapped and correlated with structural or vascular abnormalities. In all datasets, image quality was sufficient for a comprehensive image reading of the pulmonary CTA images, lung window images and pulmonary functional parameter maps and led to expedient results in each patient. With dual-source CT systems, DECT of the lung with iodine or xenon administration is technically feasible and makes it possible to depict the regional iodine or xenon distribution representing the local perfusion and ventilation. (orig.)

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

    Directory of Open Access Journals (Sweden)

    N. N. Tarabarko

    2011-01-01

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

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

    OpenAIRE

    Claassen, J.A.H.R.

    2008-01-01

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

  9. Differential diagnosis of regional cerebral hyperfixation of TC-99m HMPAO on SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shirazi, P.; Konopka, L.; Crayton, J.W. [Loyola Univ. Medical Center, Maywood, IL (United States)] [and others

    1994-05-01

    Accurate diagnostic evaluation of patients with neurologic and neuropsychiatric disease is important because early treatment may halt disease progression and prevent impairment or disability. Cerebral hyperfixation of HMPAO has been ascribed to luxury perfusion following ischemic infarction. The present study sought to identify other conditions that also display radiotracer hyperfixation in order to develop a differential diagnosis of this finding on SPECT imaging. Two hundred fifty (n=250) successive cerebral SPECT images were reviewed for evidence of HMPAO hyperfixation. Hyperfixation was defined as enhanced focal perfusion surrounded by a zone of diminished or normal cerebral perfusion. All patients were scanned after intravenous injection of 25 mCi Tc-99m HMPAO. Volume-rendered and oblique images were obtained with a Trionix triple-head SPECT system using ultra high resolution fan beam collimators. Thirteen (13/250; 5%) of the patients exhibited regions of HMPAO hyperfixation. CT or MRI abnormalities were detected in 6/13 cases. Clinical diagnoses in these patients included intractable psychosis, post-traumatic stress disorder, alcohol and narcotic dependence, major depression, acute closed-head trauma, hypothyroidism, as well as subacute ischemic infarction. A wide variety of conditions may be associated with cerebral hyperfixation of HMPAO. These conditions include neurologic and psychiatric diagnoses, and extend the consideration of hyperfixation beyond ischemic infarction. Consequently, a differential diagnosis of HMPAO hyperfixation may be broader than originally considered, and this may suggest a fundamental role for local cerebral hyperperfusion. Elucidation of the fundamental mechanism(s) for cerebral hyperperfusion requires further investigation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-03-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

  15. Adenosine stress protocols for myocardial perfusion imaging

    Directory of Open Access Journals (Sweden)

    Baškot Branislav

    2008-01-01

    Full Text Available Background/Aim. Treadmill test combined with myocardial perfusion scintigraphy (MPS is a commonly used technique in the assessment of coronary artery disease. There are many patients, however, who may not be able to undergo treadmill test. Such patients would benefit from pharmacological stress procedures combined with MPS. The most commonly used pharmacological agents for cardiac stress are coronary vasodilatators (adenosine, dipyridamol and catecholamines. Concomitant low-level treadmill exercise with adenosine pharmacologic stress (AdenoEX during MPS has become commonly used in recent years. A number of studies have demonstrated a beneficial impact of AdenoEX protocol. The aim of the study was, besides introducing into practice the two types of protocols of pharmatological stress test with adenosine, as a preparation for MPS, to compare and monitor the frequency of their side effects to quality, acquisition, as well as to standardize the onset time of acquisition (diagnostic imaging for both protocols. Methods. A total of 130 patients underwent pharmacological stress test with adenosine (vasodilatator. In 108 of the patients we performed concomitant exercise (AdenoEX of low level (50W by a bicycle ergometar. In 28 of the patients we performed Adenosine abbreviated protocol (AdenoSCAN. Side effects of adenosine were followed and compared between the two kinds of protocols AdenoEX and AdenoSCAN. Also compared were image quality and suggested time of acquisition after the stress test. Results. Numerous side effects were found, but being short-lived they did not require any active interventions. The benefit of AdenoEX versus AdenoSCAN included decreased side effects (62% vs 87%, improved safety and patients tolerance, improved target-to-background ratios because of less subdiaphragmatic activity, earlier acquisition, and improved sensitivity. Conclusion. The safety and efficacy of adenosine pharmacological stress is even better with concomitant

  16. Myocardial perfusion SPECT imaging in patients with myocardial bridging

    International Nuclear Information System (INIS)

    Objective: Stress myocardial perfusion SPECT imaging was used to assess myocardial ischemia in patients with myocardial bridging. Methods: Ninety-six patients with myocardial bridging of the left anterior descending artery documented by coronary angiography were included in this study. All under- went exercise or pharmacological stress myocardial perfusion SPECT assessing myocardial ischemia. None had prior myocardial infarction. One year follow-up by telephone interview was performed in all patients. Results The mean stenotic severity of systolic phase on angiography was (65 ± 19)%. In the SPECT study, 20 of 96 (20.8%) patients showed abnormal perfusion. This percentage was significantly higher than that of stress electrocardiogram (ECG). The higher positive rate of SPECT perfusion images was showed in the group of patients with severe systolic narrowing (≥75%) than that with mild-to-moderate systolic narrowing (50% vs 6.3%, P<0.001). The prevalence of abnormal image was significantly higher in ELDERLY PEOPLE; patients with STT change on rest ECG than in those with normal rest ECG (54.2% vs 9.7%, P<0.001). During follow-up, one patient with abnormal SPECT perfusion image sustained angina and accepted percutaneous coronary intervention, and no cardiac event occurred in patients with normal images. Conclusions: Stress myocardial perfusion SPECT imaging can be used effectively for assessing myocardial ischemia and has potential prognostic value for patients with myocardial bridging. (authors)

  17. Acute hypoxia increases the cerebral metabolic rate - a magnetic resonance imaging study.

    Science.gov (United States)

    Vestergaard, Mark B; Lindberg, Ulrich; Aachmann-Andersen, Niels Jacob; Lisbjerg, Kristian; Christensen, Søren Just; Law, Ian; Rasmussen, Peter; Olsen, Niels V; Larsson, Henrik Bw

    2016-06-01

    The aim of the present study was to examine changes in cerebral metabolism by magnetic resonance imaging of healthy subjects during inhalation of 10% O2 hypoxic air. Hypoxic exposure elevates cerebral perfusion, but its effect on energy metabolism has been less investigated. Magnetic resonance imaging techniques were used to measure global cerebral blood flow and the venous oxygen saturation in the sagittal sinus. Global cerebral metabolic rate of oxygen was quantified from cerebral blood flow and arteriovenous oxygen saturation difference. Concentrations of lactate, glutamate, N-acetylaspartate, creatine and phosphocreatine were measured in the visual cortex by magnetic resonance spectroscopy. Twenty-three young healthy males were scanned for 60 min during normoxia, followed by 40 min of breathing hypoxic air. Inhalation of hypoxic air resulted in an increase in cerebral blood flow of 15.5% (p = 0.058), and an increase in cerebral metabolic rate of oxygen of 8.5% (p = 0.035). Cerebral lactate concentration increased by 180.3% ([Formula: see text]), glutamate increased by 4.7% ([Formula: see text]) and creatine and phosphocreatine decreased by 15.2% (p[Formula: see text]). The N-acetylaspartate concentration was unchanged (p = 0.36). In conclusion, acute hypoxia in healthy subjects increased perfusion and metabolic rate, which could represent an increase in neuronal activity. We conclude that marked changes in brain homeostasis occur in the healthy human brain during exposure to acute hypoxia. PMID:26661163

  18. Magnetic resonance imaging (MRI) of cerebral infarction

    International Nuclear Information System (INIS)

    Fifty-five patients with cerebral infarction were studied with magnetic resonance imaging (MRI) and correlative CT scans. MRI was more sensitive than CT for detecting cerebral infarction, and T2-weighted spin-echo (SE) pulse sequence was most sensitive for detecting cerebral infarction except for some subcortical infarction. The size of infarcted areas on MRI was larger than that on CT in 29 of 51 infarcted areas, equal in 22. The pulse sequence using long repetition time (TR) and double echo delay time (TE), such as SE (2000/30, 90), improved the detectability of cerebral infarction. (author)

  19. Diagnostic value of perfusion source images in hyperacute stroke

    International Nuclear Information System (INIS)

    Objective: To investigate the diagnostic value of CT perfusion source images (CTPSI) in acute stroke less than 9 hours. Methods: 'One-stop' CT examination were performed in 100 patients with symptoms of acute stroke in less than 9 hours. Patients were divided into two groups according to with and without delayed perfusion on CTPSI, and compared Alberta stroke program early CT score study (ASPECTS) scores on non-contrast CT, arterial phase CTPSI and venous phase CTPSI with follow-up imaging. The ASPECTS were analyzed on arterial phase CTPSI and venous phase CTPSI using Wilcoxon rank-sum test, then compared with the follow up imaging ASPECTS using multiple linear regressions. Results: The median (min-max) scores of ASPECTS on NCCT, arterial phase CTPSI, venous phase CTPSI and follow-up imaging were 8.0 (6.0-10.0), 7.0 (1.0-8.0), 8.0 (3.0-10.0) and 7.5 (0-10.0) i group with delayed perfusion, respectively, and 8.0 (1.0-10.0), 7.5 (1.0-10.0), 8.5 (1.0-10.0) and 7.0 (0-10.0) in group without delayed perfusion respectively. ASPECTS scores measured on arterial phase CTPSI did not differ with venous phase CTPSI group without delayed per-fusion (Z=-1.00, P=0.459), while there was statistic difference in group with delayed perfusion (Z=-3.08, P=0.001). There were significant correlation of ASPECTS scores measured on mon-contrast CT, arterial phase CTPSI and venous phase CTPSI to follow-up imaging ASPECTS (r=0.879, 0.902, 0.945, P<0.01) in group without delayed perfusion; ASPECTS measured in venous phase CTPSI showed the best correlation to follow-up imaging ASPECTS (r=0.831, P=0.004) in group with delayed perfusion. Multiple linear regression showed that the correlation in only venous phase CTPSI with follow-up imaging ASPECTS was statistically significant: in group without delayed perfusion, β=0.946, P<0.001; in group with delayed perfusion, β=0.714, P=0.003. Conclusion: Presence of delayed perfusion in CTPSI is quit important in identifying ischemic penumbra, which plays

  20. Differences in 99mTc-HMPAO brain SPET perfusion imaging between Tourette's syndrome and chronic tic disorder in children

    International Nuclear Information System (INIS)

    Early differential diagnosis between Tourette's syndrome and chronic tic disorder is difficult but important because both the outcome and the treatment of these two childhood-onset diseases are distinct. We assessed the sensitivity and specificity of brain single-photon emission tomography (SPET) perfusion imaging in distinguishing the two diseases, and characterized their different cerebral perfusion patterns. Twenty-seven children with Tourette's syndrome and 11 with chronic tic disorder (mean age 9.5 and 8.6 years, respectively) underwent brain SPET with technetium-99m hexamethylpropylene amine oxime (HMPAO). Visual interpretation and semi-quantitative analysis of SPET images were performed. On visual interpretation, 22 of 27 (82%) of the Tourette's syndrome group had lesions characterized by decreased perfusion. The left hemisphere was more frequently involved. None of the children with chronic tic disorder had a visible abnormality. Semi-quantitative analysis showed that, compared with children with chronic tic disorder, children with Tourette's syndrome had significantly lower perfusion in the left lateral temporal area and asymmetric perfusion in the dorsolateral frontal, lateral and medial temporal areas. In conclusion, using the visual approach, brain SPET perfusion imaging is sensitive and specific in differentiating Tourette's syndrome and chronic tic disorder. The perfusion difference between the two groups, demonstrated by semi-quantitative analysis, may be related more to the co-morbidity in Tourette's syndrome than to tics per se. (orig.)

  1. Automatic quantitative analysis of cardiac MR perfusion images

    NARCIS (Netherlands)

    Breeuwer, Marcel; Spreeuwers, Luuk; Quist, Marcel

    2001-01-01

    Magnetic Resonance Imaging (MRI) is a powerful technique for imaging cardiovascular diseases. The introduction of cardiovascular MRI into clinical practice is however hampered by the lack of efficient and accurate image analysis methods. This paper focuses on the evaluation of blood perfusion in the

  2. Digital perfusion images for estimating redistribution of pulmonary perfusion in patients with congestive heart failure

    International Nuclear Information System (INIS)

    For estimating redistribution of pulmonary perfusion in congestive heart failure (CHF), Tc-99m MAA pulmonary perfusion images were computerized to digital perfusion images (DPLs), and 100%-70% discount area was defined as hyperperfusion area (H). Various types of DPI were obtained from patients with various degree of CHF; however, they were simply classified into six types according to patterns of H, that is, from basal triangle to apical circle. DPIs changed according to aggravation and improvement of CHF. Patients without H in the lower zone suffered from refractory CHF, and their 2-year mortality was high (59%; 13 of 22). DPIs were useful for determining therapeutic policy and estimating prognosis of patients with CHF

  3. 基于动脉自旋标记技术的内侧颞叶癫痫病人脑血流灌注成像研究%A Cerebral Blood Flow Perfusion Analysis in Patients with Temporal Lobe Epilepsy by Use of Arterial Spin Labeled Perfusion MR Imaging

    Institute of Scientific and Technical Information of China (English)

    郭超; 郑罡; 陈春晓; 沈连芳; 张志强; 王利; 卢光明

    2011-01-01

    Using arterial spin labeling (ASL), the authors have studied and analyzed the present of perfusion abnormalities in patients with mesial temporal lobe epilepsy (mTLE). 30 interictal patients with mTLE and hippocampal sclerosis (HS) including 16 patients with left mTLE (LTLE) and 14 patients with right mTLE (RTLE), and 22 healthy volunteers underwent pulsed ASL (PASL) in resting state. Relative cerebral blood flow (rCBF) was calculated and compared using group analysis of statistic parameters mapping and perfusion asymmetric index of region of interest. The results demonstrated that compared to controls, the rCBF of epileptics decreased in bilateral parahippocampal, fusiform, frontal lobe, temporal lobe and ipsilateral insula, and hippocampus in patients with LTLE, bilateral hippocampus, parahippocampal, fusiform, frontal lobe and temporal lobe, and ipsilateral amygdale and insula in patients with RTLE, but decreasing degree and area in ipsilateral side was much more than contralateral side. This study provided evidences that the HS may cause functional abnormalities in seizure zones and influence the whole brain through seizures in patients with mTLE.%基于动脉自旋标记(arterial spin labeling,ASL)技术,分析内侧颞叶癫痫(mesialtemporal lobe epilepsy,mTLE)患者大脑血流灌注(perfusion)的改变情况.在静息态下,采集了30例内侧颞叶癫痫伴单侧海马硬化发作间期患者(其中左侧16例,右侧14例)及22例健康志愿者的ASL数据,并通过计算获取其相对脑血流量(relative CBF,rCBF)及灌注不对称率(asymmetric index,AI).癫痫病人与正常人的比较结果表明:左侧mTLE患者在两侧海马旁回、梭状回、额叶、颞叶和患侧海马回及岛叶,右侧mTLE患者在两侧海马回、海马旁回、额叶、颞叶和患侧杏仁核及岛叶,rCBF均有所下降,且患侧的下降程度和范围均大于对侧.说明mTLE患者的海马硬化可能导致了痫灶区功能异常,并通过癫痫的发作影响到全脑.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  5. Ventilation-perfusion lung imaging in diaphragmatic paralysis

    International Nuclear Information System (INIS)

    Clinical, radiological, physiological, and lung imaging findings from a patient with paralysis of the diaphragm are described. Dyspnea, hypoxemia and hypercapnia increased when the patient changed from the upright to the supine positions. Ventilation (V) and perfusion (P) images of the right lung appeared to be relatively normal and remained nearly the same in the upright and supine positions. In contrast, V/P images of the left lung were smaller than those of the right lung in the upright position and decreased further in the supine position. In addition, the size of the ventilation image was much smaller than that of the perfusion

  6. Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

    Energy Technology Data Exchange (ETDEWEB)

    Altinok, Deniz; Agarwal, Ajay [Children' s Hospital of Michigan, Department of Radiology, Detroit, MI (United States); Ascadi, Gyula; Luat, Aimee; Tapos, Daniela [Children' s Hospital of Michigan, Department of Neurology, Detroit, MI (United States)

    2010-12-15

    We report on an 11-year-old girl suffering from a typical attack of hemiplegic migraine with characteristic abnormalities in perfusion MR and susceptibility-weighted MR imaging findings. The imaging abnormalities were resolved 48 h after the attack. Susceptibility-weighted MR imaging findings correlated well with the MR perfusion, thus it can be used along with conventional MRI for evaluation of children with complex migraine attacks. Susceptibility-weighted MR imaging might have a diagnostic role in assessing the vascular events in hemiplegic migraine. (orig.)

  7. Pediatric hemiplegic migraine: susceptibility weighted and MR perfusion imaging abnormality

    International Nuclear Information System (INIS)

    We report on an 11-year-old girl suffering from a typical attack of hemiplegic migraine with characteristic abnormalities in perfusion MR and susceptibility-weighted MR imaging findings. The imaging abnormalities were resolved 48 h after the attack. Susceptibility-weighted MR imaging findings correlated well with the MR perfusion, thus it can be used along with conventional MRI for evaluation of children with complex migraine attacks. Susceptibility-weighted MR imaging might have a diagnostic role in assessing the vascular events in hemiplegic migraine. (orig.)

  8. Ventilation--perfusion lung imaging in diaphragmatic paralysis

    International Nuclear Information System (INIS)

    We have described a patient with paralysis of the diaphragm, in whom dyspnea, hypoxemia, and hypercapnia increased when he changed from the upright to the supine position. Ventilation (V) and perfusion (P) images of the right lung appeared to be normal and remained nearly the same in the upright and supine positions. In contrast, V and P images of the left lung were smaller than those of the right lung in the upright position and decreased further in the supine position. In addition, the ventilation image of the left lung was much smaller than the perfusion image in both positions

  9. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  10. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    International Nuclear Information System (INIS)

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  11. Automatic extraction of left ventricle in SPECT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    An automatic method of extracting left ventricle from SPECT myocardial perfusion data was introduced. This method was based on the least square analysis of the positions of all short-axis slices pixels from the half sphere-cylinder myocardial model, and used a iterative reconstruction technique to automatically cut off the non-left ventricular tissue from the perfusion images. Thereby, this technique provided the bases for further quantitative analysis

  12. CT perfusion image processing: analysis of liver tumors

    OpenAIRE

    D’Antò, Michela

    2013-01-01

    Perfusion CT imaging of the liver has potential to improve evaluation of tumour angiogenesis. Quantitative parameters can be obtained applying mathematical models to Time Attenuation Curve (TAC). However, there are still some difficulties for an accurate quantification of perfusion parameters due, for example, to algorithms employed, to mathematical model, to patient’s weight and cardiac output and to the acquisition system. In this thesis, new parameters and alternative methodologies ab...

  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].

    Science.gov (United States)

    Hirano, Keiko; Fukuda, Tokiko

    2016-05-01

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

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

    OpenAIRE

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

    2007-01-01

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

  15. Parallel imaging for first-pass myocardial perfusion.

    Science.gov (United States)

    Irwan, Roy; Lubbers, Daniël D; van der Vleuten, Pieter A; Kappert, Peter; Götte, Marco J W; Sijens, Paul E

    2007-06-01

    Two parallel imaging methods used for first-pass myocardial perfusion imaging were compared in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image artifacts. One used adaptive Time-adaptive SENSitivity Encoding (TSENSE) and the other used GeneRalized Autocalibrating Partially Parallel Acquisition (GRAPPA), which are both applied to a gradient-echo sequence. Both methods were tested on 12 patients with coronary artery disease. The order of perfusion sequences was inverted in every other patient. Image acquisition was started during the administration of a contrast bolus followed by a 20-ml saline flush (3 ml/s), and the next perfusion was started at least 15 min thereafter using an identical bolus. An acceleration rate of 2 was used in both methods, and acquisition was performed during breath-holding. Significantly higher SNR, CNR and image quality were obtained with GRAPPA images than with TSENSE images. GRAPPA, however, did not yield a higher CNR when applied after the second bolus. GRAPPA perfusion imaging produced larger differences between subjects than did TSENSE. Compared to TSENSE, GRAPPA produced significantly better CNR on the first bolus. More consistent SNR and CNR were obtained from TSENSE images than from GRAPPA images, indicating that the diagnostic value of TSENSE may be better. PMID:17540280

  16. Diagnostic value of CT perfusion source images in superacute stroke

    International Nuclear Information System (INIS)

    Objective: To investigate the diagnostic value of CTP-SI in acute stroke less than 9 hours. Methods: In present study, 'one-stop shop' CT examination were performed in 34 patients with symptoms of acute stroke in less than 9 hours. We divided patients into two groups according to with and without delayed perfusion on CTP-SI, and compared ASPECTS (Alberta Stroke Program Early CT Score Study) scores on non-contrast CT (NCCT), arterial phase CTP-SI, venous phase CTP-SI with follow-up imaging. The ASPECTS were analyzed on arterial phase CTP-SI and venous phase CTP-SI using Wilcoxon rank-sum test, then compared with the follow up imaging ASPECTS using multiple linear regression. Results The median (min-max) scores of ASPECTS on NCCT, arterial phase CTP-SI, venous phase CTP-SI and follow-up imaging were 9.0(6.0-10.0), 6.5 (1.0-8.0), 8.0(3.0-10.0) and 7.0(0-10.0) in group with delayed perfusion, respectively, and 9.0 (1.0-10.0), 8.5 (1.0-10.0), 8.5(1.0-10.0) and 8.0 (0-10.0) in group without delayed perfusion respectively. ASPECTS scores measured on arterial phase CTP-SI did not differ from venous phase CTP-SI in group without delayed perfusion (Z=-1.00, P= 0.317), while there was significant difference in group with delayed perfusion(Z=-3.08, P=0.002). There were significant correlation with ASPECTS scores measured on NCCT, arterial phase CTP-SI and venous phase CTP-SI to follow-up imaging ASPECTS (r= 0.899,0.926,0.928,P<0.01) in group without delayed perfusion; ASPECTS measured in venous phase CTP-SI showed the best correlation to follow-up imaging ASPECTS (r=0.762, P=0.004) in group with delayed perfusion. Multiple linear regression showed that the correlation in only venous phase CTP-SI with follow-up imaging ASPECTS was statistically significant: in group without delayed perfusion, Beta=0.966, P<0.001; in group with delayed perfusion, Beta=0.765, P=0.004. Conclusion: Presence of delayed perfusion in CTP-SI is quite important in identifying ischemic penumbra, which

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

    Science.gov (United States)

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

    2016-04-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  20. Perfusion vector - a new method to quantify myocardial perfusion scintigraphy images: a simulation study with validation in patients

    DEFF Research Database (Denmark)

    Minarik, David; Senneby, Martin; Wollmer, Per;

    2015-01-01

    for further assisting the visual interpretation and to test the concept using simulated MPS images as well as patients. Methods The perfusion vector is based on calculating the difference between the anatomical centroid and the perfusion center of gravity of the left ventricle. Simulated MPS images were...... obtained using the SIMIND Monte Carlo program together with XCAT phantom. Four different-sized anterior and four lateral defects were simulated, and perfusion vector components x-, y-, and z-axes were calculated. For the patient study, 40 normal and 80 abnormal studies were included. Perfusion vectors were......Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...

  1. Dynamic contrast-enhanced magnetic resonance perfusion weighted imaging in astrocytomas: correlation with histopathology and immunohistochemistry

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; HUANG Shu-Lan; LI Tao; CHEN Xi-lan

    2005-01-01

    Objective:To investigate magnetic resonance perfusion weighted imaging and its relationship with the grading and the expression of vascular endothelial growth factor (VEGF) and angiogenesis in astrocytomas. Methods: A collection of 34 patients with astrocytomas proved by surgery and pathology were examined by magnetic resonance imaging(MRI), with 26 cases of grade Ⅰ - Ⅱ (low-grade) and 8 cases of grade Ⅲ- Ⅳ (high-grade). MR perfusion images were obtained with spin-echo echo planar imaging (SEEPI) techniques. Expression of VEGF was examined by immunohistochemical method of streptavidin-biotin-peroxidase (SP). The vascular development was measured by micro-vascular density (MVD) which was immunostained with anti-factor Ⅷ-related antigen monoclonal antibody. Results: Both of the expression of VEGF and the angiogenesis in 34 cases of astrocytomas were significantly correlated to the maximum relative cerebral blood volume (Max rCBV) (r= 0. 604, P<0. 001 ;r= 0. 625, P<0. 001, respectively). The Max rCBV and the expression of VEGF, MVD in high-grade astrocytomas were significantly higher than that of in low-grade astrocytomas (t= 3.0, P=0.017; t=7.08, P=0.01;t=3.37,P=0. 011, respectively). Conclusion: MR perfusion weighted imaging might be a valuable method in in vivo study of the angiogenesis of astrocytomas and evaluating their malignant degree and prognosis.

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

    Science.gov (United States)

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

    2009-04-01

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

  3. Improvement of image quality and radiation dose of CT perfusion of the brain by means of low-tube voltage (70 KV)

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhen-lin; Zhang, Kai; Li, Wang-jiang; Chen, Xian; Wu, Bin; Song, Bin [West China Hospital of Sichuan University, Department of Radiology, Chengdu, Sichuan (China); Li, Hang [Sichuan Provincial People' s Hospital, Department of Radiology, Chengdu, Sichuan (China)

    2014-08-15

    To investigate the feasibility of 70 kV cerebral CT perfusion by comparing image quality and radiation exposure to 80 kV. Thirty patients with suspected cerebral ischemia who underwent dual-source CT perfusion were divided into group A (80 kV, 150 mAs) and group B (70 kV, 150 mAs). Quantitative comparisons were used for maximum enhancement, signal-to-noise index (SNI), and values of cerebral blood flow (CBF), cerebral blood flow (CBV), mean transit time (MTT) on CBF, CBV, and MTT images, and radiation dose from these two groups. Qualitative perfusion images were assessed by two readers. Maximum enhancement for group B was higher than group A (P < 0.05). There were no significant differences between the two groups for SNI on CBF and CBV maps (P = 0.06 - 0.576), but significant differences for MTT when SNI was measured on frontal white matter and temporo-occipital white matter (P < 0.05). There were no differences among values of CBF, CBV, and MTT for both groups (P = 0.251-0.917). Mean image quality score in group B was higher than group A for CBF (P < 0.05), but no differences for CBV (P = 0.542) and MTT (P = 0.962). Radiation dose for group B decreased compared with group A. 70 kV cerebral CT perfusion reduces radiation dose without compromising image quality. (orig.)

  4. Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis

    International Nuclear Information System (INIS)

    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. We 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. (Author)

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

    International Nuclear Information System (INIS)

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

  6. Intensity correlation of ventilation-perfusion lung images

    Science.gov (United States)

    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.

  7. Improved perfusion quantification in FAIR imaging by offset correction

    DEFF Research Database (Denmark)

    Sidaros, Karam; Andersen, Irene K.; Gesmar, Henrik;

    2001-01-01

    Perfusion quantification using pulsed arterial spin labeling has been shown to be sensitive to the RF pulse slice profiles. Therefore, in Flow-sensitive Alternating-Inversion Recovery (FAIR) imaging the slice selective (ss) inversion slab is usually three to four times thicker than the imaging...

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

    International Nuclear Information System (INIS)

    To search for a novel potential SPECT cerebral blood flow perfusion imaging agent of our country knowledge property right, and to prove its SPECT cerebral perfusion imaging characteristics by animal studies. Tridentated MBPDA with N2S obtained form chemical synthesis and characterized by IR, 1H, 13C NMR, element analysis and MS, and ECD provided by Shanghai Hongqi Medicinal Factory were labeled with technetium-99m under optional conditions, respectively. Biodistribution in 40 Kung Ming mice was measured at different time points after intravenous injection of 555 ∼ 740 KBq 99Tcm-MBPDA. The uptake percent dose per organ (%ID/organ) and per gram tissue (%ID/g) were calculated. Dynamic imaging of 30 scintigrams at a rate of 2 s/frame 28 at 30 s/frame, and 50 at 60 s/frame using GE Starcam 400 AC/4000i SPECT in 2 monkeys was immediately acquired after rapid injection of 218.3 ∼ 333 MBq of 99Tcm-MBPDA or 99Tcm-ECD, and SPECT monkey whole body and cerebral tomographic imaging were performed at 70 min postinjection, and images were processed and reconstructred to be transverse, coronal and sagittal sections. Acute toxic animal trials using 2 groups of mice (n=5, each group) and apyrogen experiment in 3 rabbits were studied respectively. The radiochemical purity of 99Tcm-MBPDA abd 99Tcm-ECD was more than 95% and 97% Biodistribution results in mice showed high brain uptake and good retention, and the brain uptake percents at 2, 5, 15, 30 and 60 min postinjection were 1.85 ± 0.38, 1.80±0.02, 1.32±0.02, 1.16±0.23, and 1.17±0.05 %ID. Sixty-three point two percent of initial activity remained in brain 60 min postinjection. The blood clearance half time was less than 15 min (6.19±0.07%ID). The brain/blood ratio was 7.3 at 60 min postinjection. The cerebral dynamic blood flow perfusion imaging in monkey demonstrated at 2 min after administration to attain the maximum radioactivity of 99Tcm-MBPDA in the brain. In comparison with activity at 2 min (99Tcm-MBPDA) and 5 min

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Chien Hung Chang

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

  12. 3D GRASE PROPELLER: Improved Image Acquisition Technique for Arterial Spin Labeling Perfusion Imaging

    Science.gov (United States)

    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

  13. Pancreas tumor model in rabbit imaged by perfusion CT scans

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  15. Quantitative analysis of SPECT imaging parameters in patients with resting perfusion defects on myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Functional status/contractile behaviour of hibernating myocardium was analyzed objectively by analyzing the available quantitative parameters obtained on gated SPECT myocardial perfusion imaging (MPI) using Emory cardiac toolbox (ECTB) software. Materials and Methods: In this retrospective study, 70 patients with perfusion defects on 99Tc-Sestamibi MPI (12 females, 58 males) who also underwent 18F-FDG Cardiac PET study for assessment of hibernating myocardium were included for analysis. Patients were divided in three categories based on summed rest score (SRS) obtained from ECTB software, depicting the extent of perfusion defects. In a study population matched for extent of perfusion defects, quantitative parameters obtained from ECTB software such as left ventricular ejection fraction (LVEF), left ventricular end diastolic volume (EDV), left ventricular end systolic volume (ESV) and left ventricular stroke volume (SV) were compared between patients showing evidence of hibernating myocardium and patients showing no evidence of hibernating myocardium. Student 't' test was applied on the given observations and a P-value <0.05 was considered as a significant difference between the means in two categories. Results: There was no significant difference in LVEF, EDV, ESV and SV measurements between those who demonstrate hibernating myocardium and those who show no evidence of hibernating myocardium across all the categories of patients. Few trends were evident in the present study in LVEF, EDV and ESV measurements i.e., fall in mean LVEF with increasing SRS and rise in mean EDV and ESV with increasing SRS. Conclusions: The findings were consistent with the nature of hibernating myocardium i.e., non-contractile and dysfunctional. The fall in the LVEF was suggestive of deteriorating myocardial function with increasing extent of perfusion defects. The increasing left ventricular EDV and ESV with increasing extent of perfusion defects was suggestive of rising incidence of

  16. Caveat of measuring perfusion indexes using intravoxel incoherent motion magnetic resonance imaging in the human brain

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wen-Chau [National Taiwan University, Graduate Institute of Oncology, Taipei (China); National Taiwan University, Graduate Institute of Clinical Medicine, Taipei (China); National Taiwan University, Graduate Institute of Biomedical Electronics and Bioinformatics, Taipei (China); National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Chen, Ya-Fang; Yang, Shun-Chung; My, Pei-Chi [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Tseng, Han-Min [National Taiwan University Hospital, Department of Neurology, Taipei (China)

    2015-08-15

    To numerically and experimentally investigate the robustness of intravoxel incoherent motion (IVIM) magnetic resonance imaging in measuring perfusion indexes in the human brain. Eighteen healthy volunteers were imaged on a 3 T clinical system. Data of IVIM imaging (12 b-values ranging from 0 to 1000 s/mm{sup 2}, 12 repetitions) were fitted with a bi-exponential model to extract blood volume fraction (f) and pseudo-diffusion coefficient (D*). The robustness of measurement was assessed by bootstrapping. Dynamic susceptibility contrast (DSC) imaging and arterial spin-labelling (ASL) imaging were performed for cross-modal comparison. Numerical simulations were performed to assess the accuracy and precision of f and D* estimates at varied signal-to-noise ratio (SNR{sub b1000}). Based on our experimental setting (SNR{sub b1000} ∝ 30), the average error/variability is ∝ 5 %/25 % for f and ∝ 100 %/30 % for D* in gray matter, and ∝ 10 %/50 % for f and ∝ 300 %/60 % for D* in white matter. Correlation was found between f and DSC-derived cerebral blood volume in gray matter (r = 0.29 - 0.48 across subjects, p < 10{sup -5}), but not in white matter. No correlation was found between f-D* product and ASL-derived cerebral blood flow. f may provide noninvasive measurement of cerebral blood volume, particularly in gray matter. D* has limited robustness and should be interpreted with caution. (orig.)

  17. The measurement of diffusion and perfusion in biological systems using magnetic resonance imaging

    International Nuclear Information System (INIS)

    The aim of this review is to describe two recent developments in the use of magnetic resonance imaging (MRI) in the study of biological systems: diffusion and perfusion MRI. Diffusion MRI measures the molecular mobility of water in tissue, while perfusion MRI measures the rate at which blood is delivered to tissue. Therefore, both these techniques measure quantities which have direct physiological relevance. It is shown that diffusion in biological systems is a complex phenomenon, influenced directly by tissue microstructure, and that its measurement can provide a large amount of information about the organization of this structure in normal and diseased tissue. Perfusion reflects the delivery of essential nutrients to tissue, and so is directly related to its status. The concepts behind the techniques are explained, and the theoretical models that are used to convert MRI data to quantitative physical parameters are outlined. Examples of current applications of diffusion and perfusion MRI are given. In particular, the use of the techniques to study the pathophysiology of cerebral ischaemia/stroke is described. It is hoped that the biophysical insights provided by this approach will help to define the mechanisms of cell damage and allow evaluation of therapies aimed at reducing this damage. (author)

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

    Directory of Open Access Journals (Sweden)

    Pillai S

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2001-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-05-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

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

  4. Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis.

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-15

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

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

    International Nuclear Information System (INIS)

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

  7. Registration of Ultrasound Image Sequences for Perfusion Analysis

    Czech Academy of Sciences Publication Activity Database

    Harabis, V.; Kolář, R.; Jiřík, Radovan

    Barcelona: EURASIP, 2011, s. 1015-1019. ISSN 2076-1465. [EUSIPCO 2011: European Signal Processing Conference /19./. Barcelona (ES), 29.08.2011-02.09.2011] Institutional research plan: CEZ:AV0Z20650511 Keywords : ultrasound image sequences * perfusion analysis * registration * NMI Subject RIV: FS - Medical Facilities ; Equipment

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

    Directory of Open Access Journals (Sweden)

    Tomoyasu Takahiro

    2008-10-01

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

  9. A comparison between dopamine transporters imaging and perfusion SPECT with HMPAO-99mTc in the diagnosis of dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Scintigraphic imaging of dementia relies today essentially on the study of brain single photo emission computed tomography (SPECT) perfusion, after intravenous injection of 99mTc radiopharmaceutical. This paper is based on the guidelines published in October 2001 by the European Association of Nuclear medicine (http:// eanm.org). Dementia with Lewy bodies is the second cause of degenerative dementia. Differential diagnosis may be difficult, in spite of the emergence of standardized diagnostic criteria. Tomo-scintigraphy using iodine 123-labelled FP-CIT (DaTSCAN) could play a role in this process. Cerebral perfusion SPECT imaging is an important step of demented patient evaluation. We compared the diagnostic performance of both of these procedures in the diagnosis of dementia with Lewy bodies. We studied 15 patients; ten DaTSCAN and 14 cerebral perfusion studies were performed. Clinical diagnosis at the end of follow-up was established as the diagnostic reference. Cerebral perfusion SPECT showed a very low sensitivity (20%) and a good specificity (89%); considering a prevalence of dementia with Lewy bodies of 20%, positive predictive value (PPV) was 31% and negative predictive value (NPV) 82%. Performances of DaTSCAN tomo-scintigraphy were more encouraging, (sensitivity and specificity of 100%); predictive values are both of 100%. As a conclusion, DaTSCAN tomo-scintigraphy performs better than cerebral perfusion SPECT in the diagnosis of dementia with Lewy bodies and no conjoint or sequential use of those tests can be recommended. (authors)

  10. Experimental study of astrocytic swelling in rats and evaluation with CT perfusion imaging and histopathology

    International Nuclear Information System (INIS)

    Objective: To evaluate the influence of astrocytic swelling on regional cerebral blood flow. Methods: Sixteen male Wistar rats weighing from 280 g to 360 g were used. 1-aminocyclopentanetrans-1, 3-dicarboxylic acid (tACPD) was microinjected into the right caudatum. Brain water content was determined by a wet weight/dry weight technique. Dynamic CT perfusion imaging was achieved from personal computer aided mapping. Extravasation of Evan's blue (EB) into the brain was determined as an indicator of disturbance in the blood-brain barrier (BBB) and endothelial cells. Histopathologic examination by both light and electron microscopy was performed in 6 hours after injection surgery. Results: Brain edema was induced after tACPD injection and astrocytic swelling was showed in histopathologic examination. EB extravasation showed no blue stain, indicating no increase in BBB permeability induced by tACPD-injection. Electron microscope study confirmed this finding and revealed remarkable swelling of astrocytes, especially endfoot processes of astrocytes around capillaries at 6 h after tACPD-injection. The abnormal extent on CT perfusion images matched with abnormal extent on histopathologic examination. There were statistical significant differences between operated group and control group (P<0.05). Conclusion: Astrocytic swelling can induce or deteriorate the decrease of regional cerebral blood flow. The effectually remission of primary astrocytic swelling may provide new clues for the therapeutic intervention

  11. Diagnosis of pneumothorax by ventilation-perfusion imaging

    International Nuclear Information System (INIS)

    Two patients with pneumothorax had ventilation-perfusion studies to rule out the possibility of pulmonary embolism; the presence of air in the pleural space was not known to the authors when the study was analyzed. A typical ventilatory pattern characterized by small volume difference at total lung capacity followed by disproportionately greater decrease of the volume of the affected lung at tidal breathing was observed. In one case, the routine chest radiograph failed to demonstrate air in the pleural space. A similar volume difference between the two lungs was noted on the perfusion images

  12. Positron Emission Tomography Imaging of Regional Pulmonary Perfusion and Ventilation

    OpenAIRE

    Musch, Guido; Venegas, Jose G.

    2005-01-01

    Positron emission tomography (PET) imaging is a noninvasive, quantitative method to assess pulmonary perfusion and ventilation in vivo. The core of this article focuses on the use of [13N]nitrogen (13N2) and PET to assess regional gas exchange. Regional perfusion and shunt can be measured with the 13N2–saline bolus infusion technique. A bolus of 13N2, dissolved in saline solution, is injected intravenously at the start of a brief apnea, while the tracer kinetics in the lung is measured by a s...

  13. Dynamic chest image analysis: model-based pulmonary perfusion analysis with pyramid images

    Science.gov (United States)

    Liang, Jianming; Haapanen, Arto; Jaervi, Timo; Kiuru, Aaro J.; Kormano, Martti; Svedstrom, Erkki; Virkki, Raimo

    1998-07-01

    The aim of the study 'Dynamic Chest Image Analysis' is to develop computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected at different phases of the respiratory/cardiac cycles in a short period of time. We have proposed a framework for ventilation study with an explicit ventilation model based on pyramid images. In this paper, we extend the framework to pulmonary perfusion study. A perfusion model and the truncated pyramid are introduced. The perfusion model aims at extracting accurate, geographic perfusion parameters, and the truncated pyramid helps in understanding perfusion at multiple resolutions and speeding up the convergence process in optimization. Three cases are included to illustrate the experimental results.

  14. Perfusion MRI (dynamic susceptibility contrast imaging) with different measurement approaches for the evaluation of blood flow and blood volume in human gliomas

    DEFF Research Database (Denmark)

    Thomsen, Henrik; Larsson, Elna-Marie; Steffensen, Elena

    2012-01-01

    Background: Perfusion magnetic resonance imaging (MRI) is increasingly used in the evaluation of brain tumors. Relative cerebral blood volume (rCBV) is usually obtained by dynamic susceptibility contrast (DSC) MRI using normal appearing white matter as reference region. The emerging perfusion...... glioblastomas. Results: rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r ¼ 0.60) and to the cerebellum (r ¼ 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated...

  15. CT Perfusion: applications in neuroimaging

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  17. Clinical Neuroimaging of cerebral ischemia

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2013-07-01

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

  19. A review on electrical impedance tomography for pulmonary perfusion imaging

    International Nuclear Information System (INIS)

    Although electrical impedance tomography (EIT) for ventilation monitoring is on the verge of clinical trials, pulmonary perfusion imaging with EIT remains a challenge, especially in spontaneously breathing subjects. In anticipation of more research on this subject, we believe a thorough review is called for. In this paper, findings related to the physiological origins and electrical characteristics of this signal are summarized, highlighting properties that are particularly relevant to EIT. The perfusion impedance change signal is significantly smaller in amplitude compared with the changes due to ventilation. Therefore, the hardware used for this purpose must be more sensitive and more resilient to noise. In previous works, some signal- or image-processing methods have been required to separate these two signals. Three different techniques are reviewed in this paper, including the ECG-gating method, frequency-domain-filtering-based methods and a principal-component-analysis-based method. In addition, we review a number of experimental studies on both human and animal subjects that employed EIT for perfusion imaging, with promising results in the diagnosis of pulmonary embolism (PE) and pulmonary arterial hypertension as well as other potential applications. In our opinion, PE is most likely to become the main focus for perfusion EIT in the future, especially for heavily instrumented patients in the intensive care unit (ICU). (paper)

  20. Machine Learning Algorithms at Myocardial Perfusion Imaging - a Preliminary Study

    OpenAIRE

    Vieira, Domingos, frei; Silva, Emanuel; Machado, Maria; Cunha, Lídia; Metello, Luís F.

    2010-01-01

    Introduction: A major focus of data mining process - especially machine learning researches - is to automatically learn to recognize complex patterns and help to take the adequate decisions strictly based on the acquired data. Since imaging techniques like MPI – Myocardial Perfusion Imaging on Nuclear Cardiology, can implicate a huge part of the daily workflow and generate gigabytes of data, there could be advantages on Computerized Analysis of data over Human Analysis: shorter time, homogene...

  1. Magnetic Resonance Imaging in Ischemic Stroke and Cerebral Venous Thrombosis.

    Science.gov (United States)

    Krieger, Daniel A; Dehkharghani, Seena

    2015-12-01

    Imaging is indispensable in the evaluation of patients presenting with central nervous system emergencies. Although computed tomography (CT) is the mainstay of initial assessment and triage, magnetic resonance imaging (MRI) has become vital in expanding diagnostic capabilities, refining management strategies, and developing our understanding of disease processes. Ischemic stroke and cerebral venous thrombosis are 2 areas wherein MRI is actively revolutionizing patient care. Familiarity with the imaging manifestations of these 2 disease processes is crucial for any radiologist reading brain MR studies. In this review, the fundamentals of image interpretation will be addressed in-depth. Furthermore, advanced imaging techniques which are redefining the role of emergency MRI will be outlined, with a focus on the pathophysiological mechanisms that underlie image interpretation. In particular, emerging data surrounding the use of MR perfusion imaging in acute stroke management portend dramatic shifts in neurointerventional management. To this end, a review of the recent stroke literature will hopefully enhance the radiologist's role in both meaningful reporting and multidisciplinary teamwork. PMID:26636639

  2. Unevenness of lung perfusion images and pulmonary diseases

    International Nuclear Information System (INIS)

    The purpose of the study was to quantify the unevenness of perfusion distribution in the lungs in conjunction with underlying lung pathology. Twenty-one parameters as described previously were defined out of horizontal radioactive count profiles on perfusion lung image data taken in 64x64 matrixes. Principal component analysis has revealed that the 1st component or Z1 is represented by AREA, the area of the lung, and ANG, the slope of the mean count profile, Z2, by N, the number of peaks, Z3 and Z4, by YG and XG, the barycentric coordinates of count distribution, Z5, by MAC, the maximal count and Z6, by CSD, the degree of scatter in count from the peak count. How those parameters differ in each lung pathology has been determined from 657 lung perfusion image data. In pulmonary emphysema, the lung volumes are larger than those in normal subjects. The AREA and ANG were consequently larger in value and N was also significantly larger, indicating the increased regional alveolar pressure and the compressed or destroyed vascular beds. In diffuse panbronchiolitis (DPB), N was increased probably because the distal airways were either narrowed or obstructed by inflammatory processes inducing regional alveolar hypoxia and/or alveolar hyperinflation. In fibrosis, both AREA and N were significantly smaller. In congestive heart failure with postcapillary pulmonary hypertension, YG was smaller probably because of 'reversal of perfusion'. In pulmonary sarcoidosis, an increase in YG was the only abnormality. (author)

  3. Unevenness of lung perfusion images and pulmonary diseases

    Energy Technology Data Exchange (ETDEWEB)

    Teshima, Takeo; Isawa, Toyoharu; Hirano, Tomio; Anazawa, Yoshiki; Miki, Makoto; Konno, Kiyoshi; Motomiya, Masakichi (Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis and Cancer)

    1989-07-01

    The purpose of the study was to quantify the unevenness of perfusion distribution in the lungs in conjunction with underlying lung pathology. Twenty-one parameters as described previously were defined out of horizontal radioactive count profiles on perfusion lung image data taken in 64x64 matrixes. Principal component analysis has revealed that the 1st component or Z1 is represented by AREA, the area of the lung, and ANG, the slope of the mean count profile, Z2, by N, the number of peaks, Z3 and Z4, by YG and XG, the barycentric coordinates of count distribution, Z5, by MAC, the maximal count and Z6, by CSD, the degree of scatter in count from the peak count. How those parameters differ in each lung pathology has been determined from 657 lung perfusion image data. In pulmonary emphysema, the lung volumes are larger than those in normal subjects. The AREA and ANG were consequently larger in value and N was also significantly larger, indicating the increased regional alveolar pressure and the compressed or destroyed vascular beds. In diffuse panbronchiolitis (DPB), N was increased probably because the distal airways were either narrowed or obstructed by inflammatory processes inducing regional alveolar hypoxia and/or alveolar hyperinflation. In fibrosis, both AREA and N were significantly smaller. In congestive heart failure with postcapillary pulmonary hypertension, YG was smaller probably because of 'reversal of perfusion'. In pulmonary sarcoidosis, an increase in YG was the only abnormality. (author).

  4. Ventilation and perfusion magnetic resonance imaging of the lung

    International Nuclear Information System (INIS)

    A close interaction between the respiratory pump, pulmonary parenchyma and blood circulation is essential for a normal lung function. Many pulmonary diseases present, especially in their initial phase, a variable regional impairment of ventilation and perfusion. In the last decades various techniques have been established to measure the lung function. Besides the global pulmonary function tests (PFTs) imaging techniques gained increasing importance to detect local variations in lung function, especially for ventilation and perfusion assessment. Imaging modalities allow for a deeper regional insight into pathophysiological processes and enable improved planning of invasive procedures. In contrast to computed tomography (CT) and the nuclear medicine techniques, magnetic resonance imaging (MRI), as a radiation free imaging modality gained increasing importance since the early 1990 for the assessment of pulmonary function. The major inherent problems of lung tissue, namely the low proton density and the pulmonary and cardiac motion, were overcome in the last years by a constant progress in MR technology. Some MR techniques are still under development, a process which is driven by scientific questions regarding the physiology and pathophysiology of pulmonary diseases, as well as by the need for fast and robust clinically applicable imaging techniques as safe therapy monitoring tools. MRI can be considered a promising ionizing-free alternative to techniques like CT or nuclear medicine techniques for the evaluation of lung function. The goal of this article is to provide an overview on selected MRI techniques for the assessment of pulmonary ventilation and perfusion

  5. Multiparametric Characterization of Grade 2 Glioma Subtypes Using Magnetic Resonance Spectroscopic, Perfusion, and Diffusion Imaging1

    Science.gov (United States)

    Bian, Wei; Khayal, Inas S; Lupo, Janine M; McGue, Colleen; Vandenberg, Scott; Lamborn, Kathleen R; Chang, Susan M; Cha, Soonmee; Nelson, Sarah J

    2009-01-01

    BACKGROUND AND PURPOSE: The purpose of this study was to derive quantitative parameters from magnetic resonance (MR) spectroscopic, perfusion, and diffusion imaging of grade 2 gliomas according to the World Health Organization and to investigate how these multiple imaging modalities can contribute to evaluating their histologic subtypes and spatial characteristics. MATERIALS AND METHODS: MR spectroscopic, perfusion, and diffusion images from 56 patients with newly diagnosed grade 2 glioma (24 oligodendrogliomas, 18 astrocytomas, and 14 oligoastrocytomas) were retrospectively studied. Metabolite intensities, relative cerebral blood volume (rCBV), and apparent diffusion coefficient (ADC) were statistically evaluated. RESULTS: The 75th percentile rCBV and median ADC were significantly different between oligodendrogliomas and astrocytomas (P < .0001) and between oligodendrogliomas and oligoastrocytomas (P < .001). Logistic regression analysis identified both 75th percentile rCBV and median ADC as significant variables in the differentiation of oligodendrogliomas from astrocytomas and oligoastrocytomas. Group differences in metabolite intensities were not significant, but there was a much larger variation in the volumes and maximum values of metabolic abnormalities for patients with oligodendroglioma compared with the other tumor subtypes. CONCLUSIONS: Perfusion and diffusion imaging provide quantitative MR parameters that can help to differentiate grade 2 oligodendrogliomas from grade 2 astrocytomas and oligoastrocytomas. The large variations in the magnitude and spatial extent of the metabolic lesions between patients and the fact that their values are not correlated with the other imaging parameters indicate that MR spectroscopic imaging may provide complementary information that is helpful in targeting therapy, evaluating residual disease, and assessing response to therapy. PMID:19956389

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

    Science.gov (United States)

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

    2016-01-01

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

  7. Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

    Science.gov (United States)

    Liang, Jianming; Järvi, Timo; Kiuru, Aaro; Kormano, Martti; Svedström, Erkki

    2003-12-01

    The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion analysis. According to perfusion properties, we first devise a novel mathematical function to form a perfusion model. A simple yet accurate approach is further introduced to extract cardiac systolic and diastolic phases from the heart, so that this cardiac information may be utilized to accelerate the perfusion analysis and improve its sensitivity in detecting pulmonary perfusion abnormalities. This makes perfusion analysis not only fast but also robust in computation; consequently, perfusion analysis becomes computationally feasible without using contrast media. Our clinical case studies with 52 patients show that this technique is effective for pulmonary embolism even without using contrast media, demonstrating consistent correlations with computed tomography (CT) and nuclear medicine (NM) studies. This fluoroscopical examination takes only about 2 seconds for perfusion study with only low radiation dose to patient, involving no preparation, no radioactive isotopes, and no contrast media.

  8. Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

    Directory of Open Access Journals (Sweden)

    Kiuru Aaro

    2003-01-01

    Full Text Available The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion analysis. According to perfusion properties, we first devise a novel mathematical function to form a perfusion model. A simple yet accurate approach is further introduced to extract cardiac systolic and diastolic phases from the heart, so that this cardiac information may be utilized to accelerate the perfusion analysis and improve its sensitivity in detecting pulmonary perfusion abnormalities. This makes perfusion analysis not only fast but also robust in computation; consequently, perfusion analysis becomes computationally feasible without using contrast media. Our clinical case studies with 52 patients show that this technique is effective for pulmonary embolism even without using contrast media, demonstrating consistent correlations with computed tomography (CT and nuclear medicine (NM studies. This fluoroscopical examination takes only about 2 seconds for perfusion study with only low radiation dose to patient, involving no preparation, no radioactive isotopes, and no contrast media.

  9. Contrast MR imaging of acute cerebral infarction

    International Nuclear Information System (INIS)

    Thirty patients with acute and subacute cerebral infarction (13 and 17 deep cerebral infarction) were studied with 0.5 T MR unit before and after intravenous injection of Gd-DTPA. Thirteen patients were studied within 7 days after neurological ictus, 17 patients were studied between 7 and 14 days. Two types of abnormal enhancement, cortical arterial and parenchymal enhancement, were noted. The former was seen in 3 of 4 cases of very acute cortical infarction within 4 days after clinical ictus. The latter was detected in all 7 cases of cortical infarction after the 6th day of the ictus, and one patient with deep cerebral infarction at the 12th day of the ictus. Gd-DTPA enhanced MR imaging seems to detect gyral enhancement earlier compared with contrast CT, and depict intra-arterial sluggish flow which was not expected to see on contrast CT scans. (author)

  10. Role of myocardial perfusion imaging in acute coronary syndrome

    International Nuclear Information System (INIS)

    Full text: In the cardiac emergency department, a number of patients present with acute chest pain. In case of non diagnostic ECG and enzymes, accurately categorizing the patient in high and low probability is difficult. Aim of study was to evaluate the role of resting myocardial perfusion imaging (MPI) in patients with acute coronary syndrome (ACS) and then to compare the results with subsequent stress imaging. Material and Methods. A total of 34 patients were selected for the study, which were divided into three groups on the basis of respective probabilities of having ACS. This probability was decided on the basis of nature of chest pain, ECG findings, enzymes levels, and age and sex. Arbitrary score was given to patient's condition. This score ranged from 1 to 14. Patients with score between 1-6 were assigned low probability, from 7-10 were assigned intermediate probability and patients having score greater than 11 were placed in high probability groups. Patients in the low and intermediate probability groups were injected with Tc99m- MIBI within 6 hours of onset of chest pain and were undergone resting myocardial perfusion imaging (MPI) 3 to five hours after injection.. Imaging in high probability group was performed at discharge. Four weeks after the acute event all the patients underwent stress myocardial perfusion imaging. Results: All patients (100%) with low probability of ACS (n=10) showed negative resting scans. On stress MPI two patients (20%) showed new defects. Patient with high probability of ACS (n=12), all were positive 100% on resting MPI. On stress MPI, three showed (25%) no change from rest MPI, while nine patients (75%) showed augmentation of defects and four out of these nine patients (33%) also showed new perfusion defects. Patients with intermediate probability of ACS (n=12), three showed positive rest MPI (25%). On stress MPI out of these three cases, one showed (8%) no change from rest MPI and two showed (17%) augmentation of defect shown

  11. The evaluation of perfusion CT imaging in thyroid nodule

    International Nuclear Information System (INIS)

    Objective: To investigate the value of perfusion CT imaging in thyroid nodule. Methods: Of the 40 cases of post-surgical thyroid nodule identified by pathology, nodular goiter was verified in 22 cases, thyroid adenoma in 6 cases, and thyroid carcinoma in 12 cases. All cases underwent CT perfusion scan at preoperative, The perfusion parameters including the blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability of surface (PS) of region of interest (ROI) were calculated. The Mann-whitney test was used to comparing the differences of the different perfusion parameters. The ones with statistical significance would be introduced into the discriminatory analysis to distinguish the benign and malignant thyroid nodule. Results: The median MTT in 28 cases with benign thyroid nodule were 4.33 s (Min 1.42 s, Max 10.93 s), and that in 12 cases with malignant nodules were 2.18 s (Min 1.95 s, Max 2.87 s). The difference had statistical significance (P=0.00). The median BF in cases with thyroid carcinoma was 560.23 (Min 330.66, Max 1000.00) ml·100 g-1·min-1, and that in cases with the benign nodular were 374.79 (Min 117.47, Max 1000.00) ml·100 g-1·min-1. There was a significant statistical difference (P=0.01). Through the discriminatory analysis, the difference of MTT between benign and malignant nodules were statistically significant (P=0.00). After establishing the Bayes discriminatory function, the overall diagnostic accuracy was 87.5% (35/40). Conclusions: MTT and BF are useful parameters in CT perfusion imaging to distinguish the benign and malignant thyroid nodules and the MTT is more accuracy. (authors)

  12. MR imaging of glioblastoma in children: usefulness of diffusion/perfusion-weighted MRI and MR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yun-Woo; Yoon, Hye-Kyung; Roh, Hong Gee; Cho, Jae Min [Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul 135-710 (Korea); Shin, Hyung-Jin [Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Kangnam-gu, Seoul 135-710 (Korea)

    2003-12-01

    Glioblastoma is relatively uncommon in childhood and maybe difficult to differentiate from other brain tumors such as primitive neuroectodermal tumor, ependymoma, or benign astrocytoma. To describe the characteristic MR features in children with glioblastoma and to evaluate the usefulness of diffusion and perfusion MR imaging and MR spectroscopy in pediatric glioblastoma. MR imaging in 11 children (12 tumors) with biopsy-proven glioblastoma was reviewed retrospectively. In one patient, there was a recurrent glioblastoma. We reviewed CT and MRI imaging for tumor location, density/signal intensity, and enhancement pattern. Routine MR imaging was performed with a 1.5-T scanner. In six patients, diffusion-weighted MR images (DWIs) were obtained with a single-shot spin echo EPI technique with two gradient steps, and apparent diffusion coefficients (ADCs) were calculated. Using the gradient EPI technique, perfusion-weighted MR images (PWIs) were obtained in four patients from the data of dynamic MR images. The maximum relative cerebral blood volume (rCBV) ratio was calculated between the tumor and contralateral white matter in two cases. In three patients, proton MR spectroscopy was performed using a single voxel technique with either STEAM or PRESS sequences. The locations of the tumor were the thalamus and basal ganglia (n=8), deep white matter (n=3), and brain stem (n=1). Intratumoral hemorrhage was seen in four tumors. The tumors showed high-signal intensity or DWIs, having a wide range of ADC values of 0.53-1.30 (mean {+-}SD=1.011{+-}0.29). The maximum rCBV ratios of glioblastoma were 10.2 and 8.5 in two cases. MR spectroscopy showed decreased N-acetylaspartate (NAA) and increased choline in three cases. The MR findings of glioblastoma in children were: a diffusely infiltrative mass with hemorrhage involving the deep cerebral white matter, thalami, and basal ganglia. Diffusion/perfusion MR imaging and MR spectroscopy are very helpful in diagnosing glioblastoma

  13. Perfusion MR imaging and proton MR spectroscopy in a case of dysembryroplastic neuroepithelial tumor

    Institute of Scientific and Technical Information of China (English)

    WANG Liang; LI Kun-cheng; CHEN Li; LU De-hong; ZHANG Guo-jun; LI Yong-jie

    2005-01-01

    @@ Dysembryoplastic neuroepithelial tumors (DNTs), which were first described by Daumas-Duport in 1988, are one of rare benign tumors usually associated with medically intractable seizures which date from childhood.1 The clinical, pathologic and neuroradiologic findings of DNT have been described.2 Recent advances in magnetic resonance imaging (MRI) technology allow the acquisition of cerebral microcirculation parameters by perfusion weighted imaging (PWI) and brain metabolic indices by MR spectroscopy (MRS). Several studies have shown the utility of PWI and MRS can improve the diagnostic accuracy of brain tumor,3 we combine the two techniques to evaluate a case with DNT and suggest that wider application of these techniques is warranted.

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

    Directory of Open Access Journals (Sweden)

    Niklaus Denier

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

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

    Science.gov (United States)

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

    2009-07-01

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

  16. Ultrasound imaging of breast tumor perfusion and neovascular morphology.

    Science.gov (United States)

    Hoyt, Kenneth; Umphrey, Heidi; Lockhart, Mark; Robbin, Michelle; Forero-Torres, Andres

    2015-09-01

    A novel image processing strategy is detailed for simultaneous measurement of tumor perfusion and neovascular morphology parameters from a sequence of dynamic contrast-enhanced ultrasound (DCE-US) images. After normalization and tumor segmentation, a global time-intensity curve describing contrast agent flow was analyzed to derive surrogate measures of tumor perfusion (i.e., peak intensity, time-to-peak intensity, area under the curve, wash-in rate, wash-out rate). A maximum intensity image was generated from these same segmented image sequences, and each vascular component was skeletonized via a thinning algorithm. This skeletonized data set and collection of vessel segments were then investigated to extract parameters related to the neovascular network and physical architecture (i.e., vessel-to-tissue ratio, number of bifurcations, vessel count, average vessel length and tortuosity). An efficient computation of local perfusion parameters was also introduced and operated by averaging time-intensity curve data over each individual neovascular segment. Each skeletonized neovascular segment was then color-coded by these local measures to produce a parametric map detailing spatial properties of tumor perfusion. Longitudinal DCE-US image data sets were collected in six patients diagnosed with invasive breast cancer using a Philips iU22 ultrasound system equipped with a L9-3 transducer and Definity contrast agent. Patients were imaged using US before and after contrast agent dosing at baseline and again at weeks 6, 12, 18 and 24 after treatment started. Preliminary clinical results suggested that breast tumor response to neoadjuvant chemotherapy may be associated with temporal and spatial changes in DCE-US-derived parametric measures of tumor perfusion. Moreover, changes in neovascular morphology parametric measures may also help identify any breast tumor response (or lack thereof) to systemic treatment. Breast cancer management from early detection to therapeutic

  17. 2D imaging of functional structures in perfused pig heart

    Science.gov (United States)

    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.

  18. Myocardial Perfusion SPECT Imaging in Patients after Percutaneous Coronary Intervention

    OpenAIRE

    Georgoulias, Panagiotis; Valotassiou, Varvara; Tsougos, Ioannis; Demakopoulos, Nikolaos

    2010-01-01

    Coronary artery disease (CAD) is the most prevalent form of cardiovascular disease affecting about 13 million Americans, while more than one million percutaneous transluminal intervention (PCI) procedures are performed annually in the USA. The relative high occurrence of restenosis, despite stent implementation, seems to be the primary limitation of PCI. Over the last decades, single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), has proven an invaluable tool ...

  19. Ventilation and perfusion magnetic resonance imaging of the lung

    OpenAIRE

    Bauman, Grzegorz; Eichinger, Monika

    2012-01-01

    Summary A close interaction between the respiratory pump, pulmonary parenchyma and blood circulation is essential for a normal lung function. Many pulmonary diseases present, especially in their initial phase, a variable regional impairment of ventilation and perfusion. In the last decades various techniques have been established to measure the lung function. Besides the global pulmonary function tests (PFTs) imaging techniques gained increasing importance to detect local variations in lung f...

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

    Science.gov (United States)

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

    2006-03-01

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

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

    OpenAIRE

    StefanBorgwardt; Ernst-WilhelmRadue

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

  3. Visualization of perfusion changes with laser speckle contrast imaging using the method of motion history image.

    Science.gov (United States)

    Ansari, Mohammad Zaheer; Humeau-Heurtier, Anne; Offenhauser, Nikolas; Dreier, Jens P; Nirala, Anil Kumar

    2016-09-01

    Laser speckle contrast imaging (LSCI) is a real-time imaging modality reflecting microvascular perfusion. We report on the application of the motion history image (MHI) method on LSCI data obtained from the two hemispheres of a mouse. Through the generation of a single image, MHI stresses the microvascular perfusion changes. Our experimental results performed during a pinprick-triggered spreading depolarization demonstrate the effectiveness of MHI: MHI allows the visualization of perfusion changes without loss of resolution and definition. Moreover, MHI provides close results to the ones given by the generalized differences (GD) algorithm. However, MHI has the advantage of giving information on the temporal evolution of the perfusion variations, which GD does not. PMID:27321386

  4. Automated prediction of tissue outcome after acute ischemic stroke in computed tomography perfusion images

    Science.gov (United States)

    Vos, Pieter C.; Bennink, Edwin; de Jong, Hugo; Velthuis, Birgitta K.; Viergever, Max A.; Dankbaar, Jan Willem

    2015-03-01

    Assessment of the extent of cerebral damage on admission in patients with acute ischemic stroke could play an important role in treatment decision making. Computed tomography perfusion (CTP) imaging can be used to determine the extent of damage. However, clinical application is hindered by differences among vendors and used methodology. As a result, threshold based methods and visual assessment of CTP images has not yet shown to be useful in treatment decision making and predicting clinical outcome. Preliminary results in MR studies have shown the benefit of using supervised classifiers for predicting tissue outcome, but this has not been demonstrated for CTP. We present a novel method for the automatic prediction of tissue outcome by combining multi-parametric CTP images into a tissue outcome probability map. A supervised classification scheme was developed to extract absolute and relative perfusion values from processed CTP images that are summarized by a trained classifier into a likelihood of infarction. Training was performed using follow-up CT scans of 20 acute stroke patients with complete recanalization of the vessel that was occluded on admission. Infarcted regions were annotated by expert neuroradiologists. Multiple classifiers were evaluated in a leave-one-patient-out strategy for their discriminating performance using receiver operating characteristic (ROC) statistics. Results showed that a RandomForest classifier performed optimally with an area under the ROC of 0.90 for discriminating infarct tissue. The obtained results are an improvement over existing thresholding methods and are in line with results found in literature where MR perfusion was used.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

    Wang, Ze

    2012-12-01

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

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

    OpenAIRE

    Wang, Ze

    2012-01-01

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

  8. Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

    OpenAIRE

    Kiuru Aaro; Kormano Martti; Svedström Erkki; Liang Jianming; Järvi Timo

    2003-01-01

    The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion ana...

  9. Clinical value of ventilation perfusion imaging for pulmonary embolism

    International Nuclear Information System (INIS)

    The results and clinical value of ventilation perfusion (VP) imaging in 434 patients is reported. Pulmonary arteriography has been performed independently in 47 of these patients. Pulmonary arteriography provides the only specific test for intraluminal thrombus in pulmonary vessels. It is, however, invasive, time consuming and expensive, and has a significant morbidity and occasional mortality. For these reasons, VP imaging has been widely adopted as a screening test for pulmonary embolism (PE). The non-specific nature of perfusion abnormalities of lung demonstrated by this technique are a drawback, and controversy has been generated concerning the value of VP imaging to clinicians who must make decisions on clinical management. It is found that VP imaging provides valuable information in two-thirds of all patients referred to Nuclear Medicine with a clinical suspicion of PE. Among these patients, VP imaging confirmed the clinical suspicion in one-third, clarified or corrected the clinical diagnosis in one-third, and was non-diagnostic in one-third. It is concluded that VP imaging is a safe, reliable and valuable screening test in a significant number of patients suspected of having PE

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  11. Assessment of tissue viability in hyperacute infarction with using the diffusion-and perfusion-weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Mi Ock; Kim, Sang Joon; Lee, Jeong Hyun; Lee, Deok Hee; Choi, Choong Gon; Suh, Dae Chul [University of Ulsan, Asan Medical Center, Seoul (Korea, Republic of)

    2007-05-15

    The presence of a perfusion-diffusion mismatch is a useful indicator for predicting the progression of acute cerebral infarction. However, not all the area of the perfusion-diffusion mismatch progresses to infarction and a large proportion survives with hypoperfusion. The purpose of this study was to assess 1) whether tissue viability can be predicted using quantitative perfusion values and 2) whether there is correlation between the perfusion value and the time that elapsed after the onset of symptoms. Twenty-two patients with acute infarction in the middle cerebral artery territory within 12 hours after symptom onset were included in this study. We excluded those patients in whom thrombolysis was attempted or the lesion volume was less than 5 mL. Patients without perfusion-diffusion mismatch on the mean transit time (MTT)map were also excluded. We categorized the ischemic lesions into 3 areas: 1) the initial infarction, 2) the area that progressed to infarction, and 3) the hypoperfused but surviving area, based on the initial and follow up diffusion-weighted images and initial mean transit time (MTT) map. We obtained the relative cerebral blood volume (rCBV), the cerebral blood flow (rCBF) and the MTT in each early by comparing to the contralateral normal area. Statistical analysis was performed using one-way ANOVA to test whether there was a difference in perfusion values between each area. The threshold value was calculated between areas 2 and 3 using the receiver operating characteristics curve. We analyzed the correlation between the perfusion values of each area and the time that elapsed after the inset of symptoms. The perfusion values among each region were significantly different on the rCBV, rCBF and MTT maps. Between regions 2 and 3, the rCBV and rCBF maps showed a significant difference (Bonferroni post hoc analysis), but in case of rCBV, the mean perfusion values in each region approached to the normal level and it was difficult to differentiate

  12. "Matching" ventilation/perfusion images in fat embolization.

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Shinya Kobayashi

    2014-01-01

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

  14. Perfusion Magnetic Resonance Imaging: A Comprehensive Update on Principles and Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Jahng, Geon Ho [Dept. of Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Li, Ka Loh [Wolfson Molecular Imaging Center, The University of Manchester, Manchester (United Kingdom); Ostergaard, Leif [Center for Functionally Integrative Neuroscience, Dept. of Neuroradiology, Aarhus University Hospital, Aarhus (Denmark); Calamante, Femando [Florey Institute of Neuroscience and Mental Health, Heidelberg, Victoria (Austria)

    2014-10-15

    Perfusion is a fundamental biological function that refers to the delivery of oxygen and nutrients to tissue by means of blood flow. Perfusion MRI is sensitive to microvasculature and has been applied in a wide variety of clinical applications, including the classification of tumors, identification of stroke regions, and characterization of other diseases. Perfusion MRI techniques are classified with or without using an exogenous contrast agent. Bolus methods, with injections of a contrast agent, provide better sensitivity with higher spatial resolution, and are therefore more widely used in clinical applications. However, arterial spin-labeling methods provide a unique opportunity to measure cerebral blood flow without requiring an exogenous contrast agent and have better accuracy for quantification. Importantly, MRI-based perfusion measurements are minimally invasive overall, and do not use any radiation and radioisotopes. In this review, we describe the principles and techniques of perfusion MRI. This review summarizes comprehensive updated knowledge on the physical principles and techniques of perfusion MRI.

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Bradley J MacIntosh

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

  17. Differences in {sup 99m}Tc-HMPAO brain SPET perfusion imaging between Tourette's syndrome and chronic tic disorder in children

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, N.-T.; Lee, B.-F. [Dept. of Nuclear Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan (Taiwan); Chang, Y.-C. [Dept. of Pediatrics, Kaohsiung Chang Kang Children' s Hospital, Kaohsiung, Taiwan (Taiwan); Huang, C.-C. [Dept. of Pediatrics, College of Medicine, National Cheng Kung University, Tainan (Taiwan); Wang, S.-T. [Dept. of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan (Taiwan)

    2001-02-01

    Early differential diagnosis between Tourette's syndrome and chronic tic disorder is difficult but important because both the outcome and the treatment of these two childhood-onset diseases are distinct. We assessed the sensitivity and specificity of brain single-photon emission tomography (SPET) perfusion imaging in distinguishing the two diseases, and characterized their different cerebral perfusion patterns. Twenty-seven children with Tourette's syndrome and 11 with chronic tic disorder (mean age 9.5 and 8.6 years, respectively) underwent brain SPET with technetium-99m hexamethylpropylene amine oxime (HMPAO). Visual interpretation and semi-quantitative analysis of SPET images were performed. On visual interpretation, 22 of 27 (82%) of the Tourette's syndrome group had lesions characterized by decreased perfusion. The left hemisphere was more frequently involved. None of the children with chronic tic disorder had a visible abnormality. Semi-quantitative analysis showed that, compared with children with chronic tic disorder, children with Tourette's syndrome had significantly lower perfusion in the left lateral temporal area and asymmetric perfusion in the dorsolateral frontal, lateral and medial temporal areas. In conclusion, using the visual approach, brain SPET perfusion imaging is sensitive and specific in differentiating Tourette's syndrome and chronic tic disorder. The perfusion difference between the two groups, demonstrated by semi-quantitative analysis, may be related more to the co-morbidity in Tourette's syndrome than to tics per se. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Gonzalez-Brito Manuel

    2008-02-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2005-12-01

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

  1. Functional imaging for brain tumors (perfusion, DTI and MR spectroscopy); Funktionelle Bildgebung bei Hirntumoren (Perfusion, DTI, MR-Spektroskopie)

    Energy Technology Data Exchange (ETDEWEB)

    Essig, M.; Giesel, F.; Stieltjes, B.; Weber, M.A. [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Abt. Radiologie

    2007-06-15

    This contribution considers the possibilities involved with using functional methods in magnetic resonance imaging (MRI) diagnostics for brain tumors. Of the functional methods available, we discuss perfusion MRI (PWI), diffusion MRI (DWI and DTI) and MR spectroscopy (H-MRS). In cases of brain tumor, PWI aids in grading and better differentiation in diagnostics as well as for pre-therapeutic planning. In addition, the course of treatment, both after chemo- as well as radiotherapy in combination with surgical treatment, can be optimized. PWI allows better estimates of biological activity and aggressiveness in low grade brain tumors, and in the case of WHO grade II astrocytoma showing anaplastically transformed tumor areas, allows more rapid visualization and a better prediction of the course of the disease than conventional MRI diagnostics. Diffusion MRI, due to the directional dependence of the diffusion, can illustrate the course and direction of the nerve fibers, as well as reconstructing the nerve tracts in the cerebrum, pons and cerebellum 3-dimensionally. Diffusion imaging can be used for describing brain tumors, for evaluating contralateral involvement and the course of the nerve fibers near the tumor. Due to its operator dependence, DTI based fiber tracking for defining risk structures is controversial. DWI can also not differentiate accurately between cystic and necrotic brain tumors, or between metastases and brain abscesses. H-MRS provides information on cell membrane metabolism, neuronal integrity and the function of neuronal structures, energy metabolism and the formation of tumors and brain tissue necroses. Diagnostic problems such as the differentiation between neoplastic and non-neoplastic lesions, grading cerebral glioma and distinguishing between primary brain tumors and metastases can be resolved. An additional contribution will discuss the control of the course of glial tumors after radiotherapy. (orig.)

  2. Perfusion MR imaging: clinical utility for the differential diagnosis of various brain tumors

    International Nuclear Information System (INIS)

    To determine the utility of perfusion MR imaging in the differential diagnosis of brain tumors. Fifty-seven patients with pathologically proven brain tumors (21 high-grade gliomas, 8 low-grade gliomas, 8 lymphomas, 6 hemangioblastomas, 7 metastases, and 7 various other tumors) were included in this study. Relative cerebral blood volume (rCBV) and time-to-peak (TTP) ratios were quantitatively analyzed and the rCBV grade of each tumor was also visually assessed on an rCBV map. The highest rCBV ratios were seen in hemangioblastomas, followed by high-grade gliomas, metastases, low-grade gliomas, and lymphomas. There was no significant difference in TTP ratios between each tumor group (p>0.05). At visual assessment, rCBV was high in 17 (81%) of 21 high-grade gliomas and in 4 (50%) of 8 low-grade gliomas. Hemangioblastomas showed the highest rCBV and lymphomas the lowest. Perfusion MR imaging may be helpful in the differentiation of the various solid tumors found in the brain, and in assessing the grade of the various glial tumors occurring there

  3. Functional and perfusion magnetic resonance imaging at 3 tesla

    International Nuclear Information System (INIS)

    This thesis deals with the development and optimization of fast magnetic resonance imaging (MRI) methods for non-invasive functional studies of the human brain and perfusion imaging on a 3 Tesla (T) whole body NMR system. The functional MRI (fMRI) experiments performed showed that single-shot multi-echo EPI and spiral imaging techniques provide fast tools to obtain information about T2* distributions during functional activation in the human brain. Both sequences were found to be useful in the separation of different sources contributing to the functional MR signal like inflow or susceptibility effects in the various vascular environments. An fMRI study dealing with the involvement of prefrontal brain regions in movement preparation lead to inconsistent results. It could not be clarified if these were caused by problems during a spatial normalization process of the individual brains or if the functional paradigm, using very short inter-stimulus intervals, was not suited for the problem investigated. Blood flow velocity measurements in the human finger showed that the use of a strong, small-bore gradient system permits short echo times that reduce flow artefacts and allows high spatial resolution in order to keep systematic errors due to partial volume effects small. With regard to the perfusion investigations an inversion recovery snapshot-FLASH sequence was implemented, which allowed the acquisition of T1 parameter maps of the human brain within a few seconds. The accuracy of this method was demonstrated in test objects. The perfusion investigations with FAIR showed good qualitative results, whereas the quantitative analysis did not yield reproducible findings. A reason for the poor results could be the low signal-to-noise ratio (SNR) of the FAIR images or an incomplete global inversion of the magnetization due to the transmission characteristics of the radio-frequency coil. The BASE sequence that did not require a global inversion yielded quantitative perfusion

  4. Application of CT perfusion imaging in radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Objective: To investigate the value of CT perfusion imaging in evaluation of therapeutic effect and prognosis in radiotherapy for lung cancer. Methods: Fifty-one cases of lung cancer who were unable or refused to be operated on, 36 males and 15 females, aged 37-80, underwent CT perfusion imaging, 29 of which only before radiotherapy and 22 before and after radiotherapy twice. The images were collected by cine dynamic scanning (5 mm/4 slices) and input into the GE AW4.0 workstation for data processing. The slice positions of CT imaging were determined according to the largest tumor size in CT scan. Regions of interest of tumor were drawn at the region corresponding to the original images of CT perfusion. Radiotherapy was performed after CT perfusion imaging. Relevant parameters, including blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface (PS) were calculated. The treatment response after radiotherapy was evaluated by RECIST. At 2 -4 weeks after the treatment, CT examination was conducted once more. Results: The tests of the 51 patients showed that the BV was 13.6 ml·100 g-1, the BF was 129.5 ml·min-1 ·100 g-1, the MTT was 9.1 s, and the PS was 10.0 ml· min-1· 100 g-1 before radiotherapy. The tests of the 22 of the 51 patients showed that the values of BV and BF after radiotherapy were 7.6 ml· 100 g-1 and 97.8 ml·min-1· 100 g-1, respectively, both lower than those before radiotherapy (11.2 and 108.7 ml·min-1·100 g-1, respectively), however, both not significantly (t=1.28, 0.40, P>0.05); and the values of MTT and PS after radiotherapy were 8.9 s and 7.8 ml·min-1· 100 g-1, respectively, both not significantly higher than those before radiotherapy (7.2 s and 6.8 ml· min-1· 100 g-1, respectively, t=-1.15, -0.57, P>0.05). The mean area of tumor after radiotherapy was 1189.6 mm2, significantly less than that before radiotherapy (1920.3 mm2, t=3.98, P<0.05). The MTT of the SCLC patients was 12.9 s, significantly longer than

  5. Delayed imaging and additional methods to reduce subdiaphragmatic activity in myocardial perfusion SPECT imaging

    OpenAIRE

    Wosnitzer, Brian; Ata, Pashmina; DePuey, Ernest Gordon

    2015-01-01

    Compton scatter from radiotracer in structures close to the heart may partially or completely mask myocardial perfusion defects on SPECT imaging. Previous reports have discussed benefits of additional delayed imaging. We present a case in which additional delayed stress imaging reduced Compton scatter and unveiled clinically significant, stress-induced ischemia.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-15

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

  7. Newly found pulmonary pathophysiology from automated breath-hold perfusion-SPECT-CT fusion image

    International Nuclear Information System (INIS)

    Pulmonary perfusion single photon emission computed tomography (SPECT)-CT fusion image largely contributes to objective and detailed correlation between lung morphologic and perfusion impairment in various lung diseases. However, traditional perfusion SPECT obtained during rest breathing usually shows a significant mis-registration on fusion image with conventional CT obtained during deep-inspiratory phase. There are also other adverse effects caused by respiratory lung motion such as blurring or smearing of small perfusion defects. To resolve these disadvantages of traditional perfusion SPECT, an innovative method of deep-inspiratory breath-hold (DIBrH) SPECT scan is developed in the Nuclear Medicine Institute of Yamaguchi University Hospital. This review article briefly describes the new findings of pulmonary pathophysiology which has been reveled by detailed lung morphologic-perfusion correlation on automated reliable DIBrH perfusion SPECT-CT fusion image. (author)

  8. The alphabet soup of perfusion CT and MR imaging: terminology revisited and clarified in five questions

    Energy Technology Data Exchange (ETDEWEB)

    Leiva-Salinas, Carlos [University of Virginia, Department of Radiology, Neuroradiology Division, Charlottesville, VA (United States); Hospital Universitario y Politecnico la Fe, Department of Radiology, Neuroradiology Division, Valencia (Spain); Universidad Autonoma de Barcelona, Department of Medicine, Barcelona (Spain); Provenzale, James M. [Duke University Medical Center, Department of Radiology, Durham, NC (United States); Emory University School of Medicine, Departments of Radiology, Oncology and Biomedical Engineering, Atlanta, GA (United States); Kudo, Kohsuke; Sasaki, Makoto [Iwate Medical University, Division of Ultra-high Field MRI, Institute for Biomedical Sciences, Morioka (Japan); Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, Charlottesville, VA (United States); University of Virginia Medical Center, Department of Radiology, Neuroradiology Division, 1215 Lee Street-New Hospital, 1st Floor, Room 1011, PO Box 800170, Charlottesville, VA (United States)

    2012-09-15

    The five questions answered in this article revolve around the different parameters resulting from perfusion imaging processing, and this clarifies the frequently confusing terminology used to describe these parameters. More specifically, the article discusses the different imaging techniques and main mathematical models behind perfusion imaging, reviews the perfusion attributes of brain tissue, and proposes a standardized parameter terminology to facilitate understanding and avoid common misinterpretations. (orig.)

  9. The alphabet soup of perfusion CT and MR imaging: terminology revisited and clarified in five questions

    International Nuclear Information System (INIS)

    The five questions answered in this article revolve around the different parameters resulting from perfusion imaging processing, and this clarifies the frequently confusing terminology used to describe these parameters. More specifically, the article discusses the different imaging techniques and main mathematical models behind perfusion imaging, reviews the perfusion attributes of brain tissue, and proposes a standardized parameter terminology to facilitate understanding and avoid common misinterpretations. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-15

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

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

    International Nuclear Information System (INIS)

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

  12. Stress myocardial perfusion imaging versus echocardiography for the diagnosis and risk stratification of patients with CAD

    International Nuclear Information System (INIS)

    Stress myocardial perfusion imaging and stress echocardiography are both noninvasive diagnostic techniques. Both techniques are very valuable for assessment of diagnosis and risk stratification of patients with coronary artery disease, while both have their advantages and disadvantages. The overall sensitivity for diagnosis of coronary artery disease is higher by stress myocardial perfusion imaging than by stress echocardiography, whereas the specificity is slightly higher by the later. With regard to risk stratification of patients with coronary artery disease, stress myocardial perfusion imaging is more valuable than stress echocardiography. A normal stress myocardial perfusion imaging result indicate an exceedingly low risk even in patients with angiographic coronary artery disease

  13. Proton and fluorine NMR imaging for the assessment of myocardial perfusion

    International Nuclear Information System (INIS)

    A high field, small bore NMR spectrometer was converted to an imaging system for the detection of fluorine and protons in phantoms and small biological samples. The modified spectrometer system was used to image various phantoms for the assessment of imaging performance. After assessment of the imaging system performance, a water soluble fluorinated compound of relatively low toxicity was investigated for use as an imaging agent for the detection of myocardial perfusion. New Zealand white rabbits were used as the model. Hearts were rapidly extracted and hung via the aorta to a perfusion apparatus which was capable of prolonging heart function throughout the course of the experiment. Perfusion with a standard nutrient solution was followed either by perfusion with a solution to which the fluorinated compound had been added or by ligation of the left coronary artery with subsequent perfusion with the fluorinated compound in perfusate solution. The hearts were then sectioned and imaged. The ligation of the left coronary artery produced a region of impaired perfusion in the left ventricular wall and parts of the septum. The regions of reduced perfusion appeared in the F-19 NMR images as areas of reduced intensity. Proton images of the tissue sections were also obtained for comparison. It was found that infarcted regions may be best visualized by combining the fluorine and proton images. Infarct damage was verified by Gentian violet stain. Relaxation times of fluorine and protons were measured both in perfused tissue and in various concentration solutions

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-15

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

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

    International Nuclear Information System (INIS)

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

  16. Applications of radionuclide myocardial perfusion imaging in acute coronary syndrome

    International Nuclear Information System (INIS)

    In recent years, acute coronary syndrome(ACS) has been getting more and more attentions. Radionuclide myocardial perfusion imaging (MPI) can make a quick accurate diagnosis for patients with acute chest pain who cann't be diagnosed by conventional methods. The sensitivity and negative predictive value of MPI are relatively high. Besides, MPI can be applicated in the detection of ischemic and infarct size and degree, the risk stratification and the assessment of prognosis of the patients with ACS, and the appraisal of the effect of strategies. (authors)

  17. MRI methods for pulmonary ventilation and perfusion imaging

    International Nuclear Information System (INIS)

    Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment. Magnetic resonance imaging (MRI) with hyperpolarized gases, O2-enhanced MRI, MRI with fluorinated gases and Fourier decomposition MRI (FD-MRI) are available for assessment of pulmonary ventilation. For assessment of pulmonary perfusion dynamic contrast-enhanced MRI (DCE-MRI), arterial spin labeling (ASL) and FD-MRI can be used. Imaging provides a more precise insight into the pathophysiology of pulmonary function on a regional level. The advantages of MRI are a lack of ionizing radiation, which allows a protective acquisition of dynamic data as well as the high number of available contrasts and therefore accessible lung function parameters. Sufficient clinical data exist only for certain applications of DCE-MRI. For the other techniques, only feasibility studies and case series of different sizes are available. The clinical applicability of hyperpolarized gases is limited for technical reasons. The clinical application of the techniques described, except for DCE-MRI, should be restricted to scientific studies. (orig.)

  18. Tc99m-sestamibi dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    This paper addressed myocardial perfusion imaging providing a spatial dosimetric investigation of the 99mTc-radiopharmaceutical dose distribution at the myocardium. Radiological data manipulation was performed in order to create a computational voxel model of the heart. A set of images obtained by thoracic angiotomography and abdominal aorta was set up providing anatomic and functional information for heart modeling in SISCODES code. A homogeneous distribution of 99mTc was assumed into the cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissues were performed on the MCNP - Monte Carlo Code. The spatial dose distribution in the heart model is displayed as well as the dose versus volume histogram of the heart muscle. The present computational tools can generate spatial doses distribution in myocardial perfusion imaging. Specially, the dosimetry performed elucidates imparted dose distribution in the myocardial muscle per unit of injected 99m Tc activity, which can contribute to future deterministic effect investigations. (author)

  19. Potential lung perfusion imaging agent of synthetic origin

    International Nuclear Information System (INIS)

    99mTc-labelled macroaggregated albumin (MAA) is the radiopharmaceutical routinely used for perfusion lung scans. However MAA formulations contain excipients of biological origin, that may potentially cause allergic hypersensitivity in patients. The aim of this study was to prepare a non-biological lung imaging agent, with physiological uptake based on a mechanism of colloid localisation in the pulmonary vasculature. To a frozen stannous fluoride cold kit (RAH Radiopharmacy) was added 99mTc-pcrtcchnetate (99mTc-products were analysed for % radiolabelling efficiciency (RE), radioactive particle size distribution (RPSD). qualitative and quantitative rat biodistribution studies. Results indicated that all radioactive particles were formed with >99% RE. and 1-47% were >8 um. The optimum radiotracer formulation containing the highest proportion of the largest particles, was prepared by mixing SnF2 and 99mTc-pertechnetate with a low [Na+] at room temperature for 50 minutes. Results from the quantitative organ assays gave 88+/-1% tracer in the lungs. 7+/-l% in the liver and l+/-0% in the spleen. The images showed excellent lung uptake with minimal interference from liver and spleen to the lower regions of right and left lobes. In conclusion, the synthetic radiopharmaceutical 99mTc-stan-nous fluoride colloid can be prepared with a large particle size, from a commercially available cold kit in a simple and practical manner, and it has high potential for use as a perfusion imaging agent in lung scans

  20. Dynamic CT perfusion imaging of the myocardium: a technical note on improvement of image quality.

    Directory of Open Access Journals (Sweden)

    Daniela Muenzel

    Full Text Available OBJECTIVE: To improve image and diagnostic quality in dynamic CT myocardial perfusion imaging (MPI by using motion compensation and a spatio-temporal filter. METHODS: Dynamic CT MPI was performed using a 256-slice multidetector computed tomography scanner (MDCT. Data from two different patients-with and without myocardial perfusion defects-were evaluated to illustrate potential improvements for MPI (institutional review board approved. Three datasets for each patient were generated: (i original data (ii motion compensated data and (iii motion compensated data with spatio-temporal filtering performed. In addition to the visual assessment of the tomographic slices, noise and contrast-to-noise-ratio (CNR were measured for all data. Perfusion analysis was performed using time-density curves with regions-of-interest (ROI placed in normal and hypoperfused myocardium. Precision in definition of normal and hypoperfused areas was determined in corresponding coloured perfusion maps. RESULTS: The use of motion compensation followed by spatio-temporal filtering resulted in better alignment of the cardiac volumes over time leading to a more consistent perfusion quantification and improved detection of the extend of perfusion defects. Additionally image noise was reduced by 78.5%, with CNR improvements by a factor of 4.7. The average effective radiation dose estimate was 7.1±1.1 mSv. CONCLUSION: The use of motion compensation and spatio-temporal smoothing will result in improved quantification of dynamic CT MPI using a latest generation CT scanner.

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

    Science.gov (United States)

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

    2003-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-01

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

  3. A statistical investigation of normal regional intra-subject heterogeneity of brain metabolism and perfusion by F-18 FDG and O-15 H2O PET imaging

    International Nuclear Information System (INIS)

    The definite evaluation of the regional cerebral heterogeneity using perfusion and metabolism by a single modality of PET imaging has not been well addressed. Thus a statistical analysis of voxel variables from identical brain regions on metabolic and perfusion PET images was carried out to determine characteristics of the regional heterogeneity of F-18 FDG and O-15 H2O cerebral uptake in normal subjects. Fourteen normal subjects with normal CT and/or MRI and physical examination including MMSE were scanned by both F-18 FDG and O-15 H2O PET within same day with head-holder and facemask. The images were co-registered and each individual voxel counts (Q) were normalized by the gloabl maximal voxel counts (M) as R = Q/M. The voxel counts were also converted to z-score map by z = (Q - mean)/SD. Twelve pairs of ROIs (24 total) were systematically placed on the z-score map at cortical locations 15-degree apart and identically for metabolism and perfusion. Inter- and intra-subject correlation coefficients (r) were computed, both globally and hemispherically, from metabolism and perfusion: between regions for the same tracer and between tracers for the same region. Moments of means and histograms were computed globally along with asymmetric indices as their hemispherical differences. Statistical investigations verified with data showed that, for a given scan, correlation analyses are expectedly alike regardless of variables (Q, R, z) used. The varieties of correlation (r's) of normal subjects, showing symmetry, were mostly around 0.8 and with coefficient of variations near 10%. Analyses of histograms showed non-Gaussian behavior (skew = -0.3 and kurtosis = 0.4) of metabolism on average, in contrast to near Gaussian perfusion. The co-registered cerebral metabolism and perfusion z maps demonstrated regional heterogeneity but with attractively low coefficient of variations in the correlation markers

  4. Laser Speckle Imaging of Cerebral Blood Flow

    Science.gov (United States)

    Luo, Qingming; Jiang, Chao; Li, Pengcheng; Cheng, Haiying; Wang, Zhen; Wang, Zheng; Tuchin, Valery V.

    Monitoring the spatio-temporal characteristics of cerebral blood flow (CBF) is crucial for studying the normal and pathophysiologic conditions of brain metabolism. By illuminating the cortex with laser light and imaging the resulting speckle pattern, relative CBF images with tens of microns spatial and millisecond temporal resolution can be obtained. In this chapter, a laser speckle imaging (LSI) method for monitoring dynamic, high-resolution CBF is introduced. To improve the spatial resolution of current LSI, a modified LSI method is proposed. To accelerate the speed of data processing, three LSI data processing frameworks based on graphics processing unit (GPU), digital signal processor (DSP), and field-programmable gate array (FPGA) are also presented. Applications for detecting the changes in local CBF induced by sensory stimulation and thermal stimulation, the influence of a chemical agent on CBF, and the influence of acute hyperglycemia following cortical spreading depression on CBF are given.

  5. Superimposition of MR angiography and three dimensional radionuclide brain perfusion image with personal computer

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Jinsaku; Taki, Suzuka; Tanada, Kimikazu (Tonami General Hospital, Toyama (Japan))

    1994-11-01

    To investigate the correlation of arterial obstruction with brain perfusion, MR angiography (MRA) and three dimensional (3D) radionuclide brain perfusion image were superimposed. Eleven cases with intracranial artery obstructive patients were studied. Three dimensional brain perfusion images were generated based on the ray-tracing method. Superimposition of MRA on to 3D brain perfusion image was performed on a personal computer. Reconstructing time for 3D image was about 15 minutes for each patient, Superimposing time was about 5 minutes for each image. Correlation of arterial obstruction with decrease in brain perfusion was demonstrated clearly by superimposed image. With a personal computer, it was possible to produce clinically useful synthesized images with relatively short time and conveniently. (author).

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

    Directory of Open Access Journals (Sweden)

    Ansgar Reising

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

  7. Estimation of mitral stenosis by using digital perfusion images (DPI)

    International Nuclear Information System (INIS)

    Pulmonary perfusion images were modified by computer system to digital perfusion images (DPI) to estimate the distribution of pulmonary blood flow of the patients with mitral stenosis and 27 patients admitted at the Heart Institute Japan were selected and DPI were obtained by using standard method (Tc-99m MAA were injected in sitting state). DPI of the patients were classified into 6 types according to the hemodynamics and the patterns of DPI, i.e. mitral stenosis with sinus rhythm, without regurgitation, with regurgitation (10), with regurgitation (20-) with giant atrium, and with low output state. In each type the pattern of DPI changed gradually according to the hemodynamic changes and eventually showed its own characteristic patterns. Right lateral DPI (r-DPI) showed characteristic patterns which could not be suspected from both anterior and posterior DPI. Patterns of DPI changed after exercise and the postexercise DPI were similar to patterns of DPI with more pulmonary hypertensive state. From these findings it might be suspected as followings. The classification of mitral stenosis into 6 types might be reasonable from the stand point of distribution of pulmonary blood flow. The distribution of pulmonary blood flow might change according to the pulmonary hemodynamic changes. In each type there might be critical pulmonary pressure. R-DPI might be one of the best DPI to estimate the distribution of pulmonary blood flow. By using DPI it might be possible to estimate the pulmonary hemodynamics and severity of the patients with mitral stenosis. (author)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  10. A comparison between dopamine transporters imaging and perfusion SPECT with HMPAO-{sup 99m}Tc in the diagnosis of dementia with Lewy bodies; Comparaison des performances de l'imagerie des transporteurs dopaminergiques et de la tomoscintigraphie de perfusion cerebrale a l MPAO-{sup 99m}Tc dans le diagnostic de maladie a corps de Lewy diffus

    Energy Technology Data Exchange (ETDEWEB)

    Voitota, J.B.; Emptaz, A.; Szurhaj, W.; Steinling, M. [Unite d' Imagerie Fonctionnelle Cerebrale du Service Central de Medecine Nucleaire (France); Bombois, St.; Pasquier, F. [Hopital Roger-Salengro, CHRU de Lille, Centre Memoire de Ressources et de Recherche, 59 - Lille (France)

    2007-06-15

    Scintigraphic imaging of dementia relies today essentially on the study of brain single photo emission computed tomography (SPECT) perfusion, after intravenous injection of {sup 99m}Tc radiopharmaceutical. This paper is based on the guidelines published in October 2001 by the European Association of Nuclear medicine (http:// eanm.org). Dementia with Lewy bodies is the second cause of degenerative dementia. Differential diagnosis may be difficult, in spite of the emergence of standardized diagnostic criteria. Tomo-scintigraphy using iodine 123-labelled FP-CIT (DaTSCAN) could play a role in this process. Cerebral perfusion SPECT imaging is an important step of demented patient evaluation. We compared the diagnostic performance of both of these procedures in the diagnosis of dementia with Lewy bodies. We studied 15 patients; ten DaTSCAN and 14 cerebral perfusion studies were performed. Clinical diagnosis at the end of follow-up was established as the diagnostic reference. Cerebral perfusion SPECT showed a very low sensitivity (20%) and a good specificity (89%); considering a prevalence of dementia with Lewy bodies of 20%, positive predictive value (PPV) was 31% and negative predictive value (NPV) 82%. Performances of DaTSCAN tomo-scintigraphy were more encouraging, (sensitivity and specificity of 100%); predictive values are both of 100%. As a conclusion, DaTSCAN tomo-scintigraphy performs better than cerebral perfusion SPECT in the diagnosis of dementia with Lewy bodies and no conjoint or sequential use of those tests can be recommended. (authors)

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  12. Composite pseudocolor images: a technique to enhance the visual correlation between ventilation-perfusion lung images

    Science.gov (United States)

    Vaz de Carvalho, Carlos; Costa, Antonio A.; Seixas, M.; Ferreira, F. N.; Guedes, M. A.; Amaral, I.

    1993-07-01

    Lung ventilation and perfusion raw nuclear medicine images obtained from a gamma camera can be difficult to analyze on a per si basis. A method to optimize the visual correlation between these images was established through the use of new combination images: Composite Pseudo-Color (CPC) images. The major topic of this study is the assessment of the usefulness of this method in the detection of lung malfunction.

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

    International Nuclear Information System (INIS)

    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

  14. Magnetic resonance first pass perfusion imaging for detecting coronary artery disease

    International Nuclear Information System (INIS)

    Magnetic resonance first pass perfusion imaging can be used to detect abnormalities in myocardial blood flow. This technique involves imaging the first pass of gadolinium based contrast through the myocardium. Images are initially read qualitatively for areas of reduced signal intensity. Additionally, at our institution a quantitative method is applied that can aid both detection and diagnosis of perfusion defects. This method involves fitting the myocardial signal intensity curves and then calculates absolute myocardial blood flow. Our approach to first pass perfusion imaging will be reviewed. Magnetic resonance first pass perfusion imaging has a complimentary role with coronary angiography either non-invasively using CT or with catheterization. Perfusion imaging defines the physiology and angiography in the anatomy of coronary artery disease

  15. Hemodynamic segmentation of brain perfusion images with delay and dispersion effects using an expectation-maximization algorithm.

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  17. Hemodynamic segmentation of brain perfusion images with delay and dispersion effects using an expectation-maximization algorithm.

    Directory of Open Access Journals (Sweden)

    Chia-Feng Lu

    Full Text Available 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.

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

    Directory of Open Access Journals (Sweden)

    Kelly N H Nudelman

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

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

    International Nuclear Information System (INIS)

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

  20. Automatic quantitative analysis of cardiac MR perfusion images

    Science.gov (United States)

    Breeuwer, Marcel M.; Spreeuwers, Luuk J.; Quist, Marcel J.

    2001-07-01

    Magnetic Resonance Imaging (MRI) is a powerful technique for imaging cardiovascular diseases. The introduction of cardiovascular MRI into clinical practice is however hampered by the lack of efficient and accurate image analysis methods. This paper focuses on the evaluation of blood perfusion in the myocardium (the heart muscle) from MR images, using contrast-enhanced ECG-triggered MRI. We have developed an automatic quantitative analysis method, which works as follows. First, image registration is used to compensate for translation and rotation of the myocardium over time. Next, the boundaries of the myocardium are detected and for each position within the myocardium a time-intensity profile is constructed. The time interval during which the contrast agent passes for the first time through the left ventricle and the myocardium is detected and various parameters are measured from the time-intensity profiles in this interval. The measured parameters are visualized as color overlays on the original images. Analysis results are stored, so that they can later on be compared for different stress levels of the heart. The method is described in detail in this paper and preliminary validation results are presented.

  1. Perfusion lung imaging in the adult respiratory distress syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Pistolesi, M.; Miniati, M.; Di Ricco, G.; Marini, C.; Giuntini, C.

    1986-07-01

    In 29 perfusion lung scans (PLS) of 19 patients with ARDS, 20 of which were obtained within six days from the onset of respiratory symptoms, perfusion abnormalities were the rule. These included focal, nonsegmental defects, mostly peripheral and dorsal, and perfusion redistribution away from the dependent lung zones. PLS were scored for the presence and intensity of perfusion abnormalities and the scores of perfusion redistribution were validated against numerical indices of blood flow distribution per unit lung volume. PLS scores were correlated with arterial blood gas values, hemodynamic parameters, and chest radiographic scores of ARDS. Arterial oxygen tension correlated with the scores of both perfusion defects and redistribution. Perfusion defects correlated better with the radiographic score of ARDS, and perfusion redistribution with PAP and vascular resistance. ARDS patients exhibit peculiar patterns of PLS abnormalities not observed in other disorders. Thus, PLS may help considerably in the detection and evaluation of pulmonary vascular injury in ARDS.

  2. Perfusion lung imaging in the adult respiratory distress syndrome

    International Nuclear Information System (INIS)

    In 29 perfusion lung scans (PLS) of 19 patients with ARDS, 20 of which were obtained within six days from the onset of respiratory symptoms, perfusion abnormalities were the rule. These included focal, nonsegmental defects, mostly peripheral and dorsal, and perfusion redistribution away from the dependent lung zones. PLS were scored for the presence and intensity of perfusion abnormalities and the scores of perfusion redistribution were validated against numerical indices of blood flow distribution per unit lung volume. PLS scores were correlated with arterial blood gas values, hemodynamic parameters, and chest radiographic scores of ARDS. Arterial oxygen tension correlated with the scores of both perfusion defects and redistribution. Perfusion defects correlated better with the radiographic score of ARDS, and perfusion redistribution with PAP and vascular resistance. ARDS patients exhibit peculiar patterns of PLS abnormalities not observed in other disorders. Thus, PLS may help considerably in the detection and evaluation of pulmonary vascular injury in ARDS

  3. Simultaneous Multiagent Hyperpolarized 13C Perfusion Imaging

    DEFF Research Database (Denmark)

    von Morze, Cornelius; Bok, Robert A.; Reed, Galen D.;

    2014-01-01

    and spectral-spatial readout by multiband frequency encoding, designed for the wide, regular spectral separation of these compounds. We exploited the varying bilayer permeability of these tracers to quantify vascular permeability and perfusion parameters simultaneously, using perfusion modeling...

  4. Myocardial perfusion imaging in patients with a recent, normal exercise test

    DEFF Research Database (Denmark)

    Bovin, Ann; Klausen, Ib Christian; Petersen, Lars Jelstrup

    2013-01-01

    To investigate the added value of myocardial perfusion scintigraphy imaging (MPI) in consecutive patients with suspected coronary artery disease (CAD) and a recent, normal exercise electrocardiography (ECG).......To investigate the added value of myocardial perfusion scintigraphy imaging (MPI) in consecutive patients with suspected coronary artery disease (CAD) and a recent, normal exercise electrocardiography (ECG)....

  5. PET scan perfusion imaging in the Prader-Willi syndrome: new insights into the psychiatric and social disturbances

    International Nuclear Information System (INIS)

    The Prader-Willi syndrome (PWS), a rare multisystem genetic disease, leads to severe disabilities, such as morbid obesity, endocrine dysfunctions, psychiatric disorders, and social disturbances. We explored the whole brain of patients with PWS to detect abnormalities that might explain the behavioral and social disturbances, as well as the psychiatric disorders of these patients. Nine patients with PWS (six males, three females; mean age 16.4 years) underwent a positron emission tomography (PET) scan with H(2)(15)O as a tracer to measure regional cerebral blood flow (rCBF). The images were compared with those acquired from nine controls (six males, three females; mean age 21.2 years). A morphologic magnetic resonance imaging (MRI) was also performed in PWS patients, and their cognitive and behavioral skills were assessed with Wechsler Intelligence Scale for Children III and the Child Behavior Check List (CBCL). The MRI images showed no evident anatomic abnormalities, whereas PET scans revealed hypo-perfused brain regions in PWS patients compared with controls, particularly in the anterior cingulum and superior temporal regions. We observed a significant relationship (P≤0.05) between rCBF in the hypo-perfused regions and CBCL scores. The functional consequences of these perfusion abnormalities in specific brain regions might explain the behavioral and social problems observed in these individuals. (authors)

  6. Assessment of smoking-induced impairment of pulmonary perfusion using three-dimensional SPECT images

    International Nuclear Information System (INIS)

    The effects of smoking on ventilation-perfusion lung scintigrams were investigated. The subjects comprised 40 healthy males (28 smokers and 12 nonsmokers) without a history of cardiopulmonary disease and with normal chest radiographs. After acquisition of planar images of ventilation lung scintigrams with 370 MBq of 133Xe gas, planar images and SPECT images of pulmonary perfusion flow were obtained using 185 MBq of 99mTc-MAA. Planar imaging showed perfusion defects in only 5 smokers. In contrast, 16 subjects were found to have perfusion defects on SPECT images (p133Xe in 4 smokers, suggesting that smoking-induced abnormal perfusion on SPECT appears earlier than impaired ventilation on scintigrams. (author)

  7. Diagnosis of ictal hyperperfusion using subtraction image of ictal and interictal brain perfusion SPECT

    International Nuclear Information System (INIS)

    A robust algorithm to disclose and display the difference of ictal and interictal perfusion may facilitate the detection of ictal hyperfusion foci. Diagnostic performance of localizing epileptogenic zones with subtracted SPECT images was compared with the visual diagnosis using ictal and interictal SPECT, MR, or PET. Ictal and interictal Tc-99m-HMPAO cerebral perfusion SPECT images of 48 patients(pts) were processed to get parametric subtracted images. Epileptogenic foci of all pts were diagnosed by seizure free state after resection of epileptogenic zones. In subtraction SPECT, we used normalized difference ratio of pixel counts(ictal-interictal)/interictal X 100%) after correcting coordinates of ictal and interictal SPECT in semi-automatized 3-dimensional fashion. We found epileptogenic zones in subtraction SPECT and compared the performance with visual diagnosis of ictal and interictal SPECT, MR and PET using post-surgical diagnosis as gold standard. The concordance of subtraction SPECT and ictal-interictal SPECT was moderately good(kappa=0.49). The sensitivity of ictal-interictal SPECT was 73% and that of subtraction SPECT 58%. Positive predictive value of ictal-interictal SPECT was 76% and that of subtraction SPECT was 64%. There was no statistical difference between sensitivity or positive predictive values of subtraction SPECT and ictal-interictal SPECT, MR or PET. Such was also the case when we divided patients into temporal lobe epilepsy and neocortical epilepsy. We conclude that subtraction SPECT we produced had equivalent diagnostic performance compared with ictal-interictal SPECT in localizing epileptogenic zones. Additional value of these subtraction SPECT in clinical interpretation of ictal and interictal SPECT should be further evaluated

  8. Development of 17O NMR approach for fast imaging of cerebral metabolic rate of oxygen in rat brain at high field

    OpenAIRE

    Zhu, Xiao-Hong; Zhang, Yi; Tian, Run-Xia; Lei, Hao; Zhang, Nanyin; Zhang, Xiaoliang; Merkle, Hellmut; Ugurbil, Kamil; Chen, Wei(Department of Physics, State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871, China)

    2002-01-01

    A comprehensive technique was developed for using three-dimensional 17O magnetic resonance spectroscopic imaging at 9.4T for rapidly imaging the cerebral metabolic rate of oxygen consumption (CMRO2) in the rat brain during a two-min inhalation of 17O2. The CMRO2 value (2.19 ± 0.14 μmol/g/min, n = 7) was determined in the rat anesthetized with α-chloralose by independent and concurrent 17O NMR measurements of cerebral H217O content, arterial input function, and cerebral perfusion. CMRO2 values...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  11. Mean transit time image - a new method of analyzing brain perfusion studies

    International Nuclear Information System (INIS)

    Point-by-point calculation of the mean transit time based on gamma fit was used to analyze brain perfusion studies in a vertex view. The algorithm and preliminary results in normal brain and in different stages of cerebral perfusion abnormality (ischemia, stroke, migraine, tumor, abscess) are demonstrated. In contrast to the traditional methods using fixed, a priori defined regions of interest this type of mapping of the relative regions cerebral perfusion shows more clearly the irregular outlines of the disturbance. Right to left activity ratios in the arterial part of the time-activity curves showed significant correlation with the mean transit time ratios (Q1=1.185-0.192 Qsub(a), n=38, r=0.716, P<0.001). (orig.)

  12. Study on the cerebrovascular reserve capacity by MR perfusion weighted imaging in SHR

    Science.gov (United States)

    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 (Pstress test" can provide more qualitative and half-quantitative information on the cerebral perfusion to evaluate the CVRC in SHR.

  13. Non-traumatic neurological emergencies: imaging of cerebral ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Grunwald, Iris; Reith, Wolfgang [Department of Neuroradiology, Saarland University Clinic, Homburg/Saar (Germany)

    2002-07-01

    Cardiovascular disease is the leading cause of death worldwide with almost one-third of all cardiovascular deaths ascribed to stroke. Imaging modalities, such as CT, MRI, positron emission tomography (PET), and single photon emission CT (SPECT) provide tremendous insight into the pathophysiology of acute stroke. Computed tomography is considered the most important initial diagnostic study in patients with acute stroke, because underlying structural lesions, such as tumor, vascular malformation, or subdural hematoma, can mimic stroke clinically. Diffusion-weighted imaging (DWI) has the ability to visualize changes in diffusion within minutes after the onset of ischemia and has become a powerful tool in the evaluation of patients with stroke syndrome. Territories with diffusion and perfusion mismatch may define tissues at risk, but with potential recovery. An alternative strategy with CT technology uses rapid CT for dynamic perfusion imaging, with similar goals in mind. Angiography can be performed in the hyperacute stage if thrombolytic therapy is being considered. Indications for diagnostic angiography include transient ischemic attacks in a carotid distribution, amaurosis fugax, prior stroke in a carotid distribution, a high-grade stenotic lesion in a carotid artery, acquiring an angiographic correlation of magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) concerning stenotic findings. In 50% of all angiograms performed in the hyperacute stage, occlusion of a vessel is observed; however, the need for angiography has been made less necessary due to the improvements of MRA, duplex ultrasound, and CTA. Numerous etiologies can lead to infarction. In children, pediatric stroke is very uncommon. The most common cause is an embolus from congenital heart disease with right-to-left shunts. Also a dissection of large extracranial vessels may result in cerebral infarction, and although the brain is equipped with numerous venous drainage routes

  14. Non-traumatic neurological emergencies: imaging of cerebral ischemia

    International Nuclear Information System (INIS)

    Cardiovascular disease is the leading cause of death worldwide with almost one-third of all cardiovascular deaths ascribed to stroke. Imaging modalities, such as CT, MRI, positron emission tomography (PET), and single photon emission CT (SPECT) provide tremendous insight into the pathophysiology of acute stroke. Computed tomography is considered the most important initial diagnostic study in patients with acute stroke, because underlying structural lesions, such as tumor, vascular malformation, or subdural hematoma, can mimic stroke clinically. Diffusion-weighted imaging (DWI) has the ability to visualize changes in diffusion within minutes after the onset of ischemia and has become a powerful tool in the evaluation of patients with stroke syndrome. Territories with diffusion and perfusion mismatch may define tissues at risk, but with potential recovery. An alternative strategy with CT technology uses rapid CT for dynamic perfusion imaging, with similar goals in mind. Angiography can be performed in the hyperacute stage if thrombolytic therapy is being considered. Indications for diagnostic angiography include transient ischemic attacks in a carotid distribution, amaurosis fugax, prior stroke in a carotid distribution, a high-grade stenotic lesion in a carotid artery, acquiring an angiographic correlation of magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) concerning stenotic findings. In 50% of all angiograms performed in the hyperacute stage, occlusion of a vessel is observed; however, the need for angiography has been made less necessary due to the improvements of MRA, duplex ultrasound, and CTA. Numerous etiologies can lead to infarction. In children, pediatric stroke is very uncommon. The most common cause is an embolus from congenital heart disease with right-to-left shunts. Also a dissection of large extracranial vessels may result in cerebral infarction, and although the brain is equipped with numerous venous drainage routes

  15. Diffusion tensor imaging patients with major cerebral artery occlusive disease

    International Nuclear Information System (INIS)

    Diffusion tensor (DT) imaging provides quantitative information about the magnitude and the directionality (anisotropy) of water diffusion in vivo and can detect pathologic changes in brain ischemia. This study tried to detect ischemic brain damage using DT imaging in patients with symptomatic chronic major cerebral artery occlusive disease. DT imaging was performed using a 3.0 Tesla magnetic resonance (MR) scanner in 50 patients with unilateral internal carotid artery or middle cerebral artery stenosis or occlusion, who had no obvious infarct lesions on conventional MR imaging. Thirty-three patients underwent DT imaging before and after vascular reconstruction surgery. Fractional anisotropy (FA) was calculated in the middle cerebral artery territory. Preoperative FA values in the ipsilateral side were significantly lower than those in the contralateral side. After surgery, the FA value was significantly increased. DT imaging may indicate ischemic brain damage, not visualized by conventional MR imaging, in patients with major cerebral artery occlusive disease. (author)

  16. Myocardial perfusion imaging for the detection of coronary heart disease

    International Nuclear Information System (INIS)

    A method of myocardial perfusion imaging using 201Tl is described. Thallium is able to substitute for potassium in biological systems including transport by the sodium--potassium ATP-ase system. The high extraction efficiency of the heart for 201Tl offers a method whereby a tracer may be administered intravenously and is concentrated to a significant degree by the heart. However, only about 3 to 4 percent of the dose administered lodges in the myocardium. Experiments with dogs indicated that the regional distribution of Tl in the heart reflects the regional distribution of blood flow. The goal is to develop a procedure that can detect those patients with significant disease prior to the onset of a catastrophic event and studies are being undertaken to improve the sensitivity of the method for the detection of smaller lesions in the myocardium

  17. Thallium-201 myocardial perfusion imaging during transient coronary occlusion at the time of PTCA

    International Nuclear Information System (INIS)

    To evaluate myocardial perfusion during transient coronary arterial occlusion, thallium-201 was administered intravenously during percutaneous transluminall coronary angioplasty (PTCA) in 12 patients with effort angina, and the resulting perfusion images were compared with those of exercise stress obtained before PTCA. Thallium-201 was injected at the last inflation of an angioplastic baloon and occlusion was maintained for 60 to 90 sec. Three projections of planar images were obtained immediately after PTCA, using a portable gamma camera in an angiography room. These perfusion images obtained during PTCA and exercise were visually interpreted and compared. Myocardial perfusion defects due to the responsible vessel occlusion were observed at early imaging after PTCA, and were fully redistributed three hrs post injection. In 10 patients without angiographically imaged collateral vessels, there were no significatn differences in perfusion between images during PTCA and during exercise. Two patients whose collaterals were observed during coronary angiography before PTCA had higher perfusion scores during PTCA than during exercise. We concluded that intravenous injection of thallium-201 during PTCA is a useful means for assessing alteration of myocardial perfusion due to transient coronary occlusion without increasing the risk of angioplastic procedures, and that it provides more precise information about the jeopardized myocardium, perfused by antegrade blood flow. (author)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Reporting of ventilation perfusion images for pulmonary embolism

    International Nuclear Information System (INIS)

    Thirty-four hospital patients with suspected pulmonary embolism (PE) had ventilation perfusion (VP) imaging after pulmonary angiography to assess the performance of highly specific criteria for diagnosis of PE and to evaluate the precision of image reporting. A diagnostic result was obtained from VP imaging in 21 of 34 patients giving a sensitivity for PE of 80% and a specificity of 100% in this subgroup. Six of 11 patients with PE had an indeterminate study which reduced the overall sensitivity of the technique for PE in the whole group. A critical analysis of image reporting by two readers gave an 85% inter-observer agreement on ranking as diagnostic or indeterminate for PE (kappa 0.69) and 91%-94% agreement for consensus reproducibility (kappa 0.82). We conclude that the degree of accuracy and precision of reporting that can be obtained using specific criteria will provide a reliable diagnosis in a significant number of patients suspected of having PE. Consensus reporting by two readers is shown to be more reliable than individual reporting. (orig.)

  2. Factors of Transient Ischemic Dilation on Gated Myocardial Perfusion Imaging

    International Nuclear Information System (INIS)

    That transient ischemic dilation (TID) of the left ventricle on SPECT myocardial perfusion imaging (MPI) is the marker of severe and extensive coronary artery disease (CAD). But other clinic factors influencing TID is less certain. The object of this study was to investigate that of the factors,as left ventricle hypertrophy (LVH) and diabetes (DM). MPI 87 patients who undertaken coronary angiography and transthoracic echocardiography within 1 month of stress electrocardiography-gated MPI were retrospectively analyzed. TID was assessed quantitatively using a soft program.A ratio cutoff of ≥1.22 was to represent TID. Summed stress score and summed different score (ischemia score) were determined using 20-segment 5-point scoring system to quantify myocardial ischemia. LVH was defined as a left ventricular wall thickness of >11 mm on M-mode echocardiography. Severe CAD was defined as severe stenosis (≥90%) of either the left anterior descending artery or both the right coronary and lateral circumflex arteries. All of the 87 patients, 13 of them had TID, 9 of them TID had LVH, and 10 of the TID had severe CAD. A high percentage had DM (84%). Severe CAD,diabetes and LVH were independent predictors of TID, the effect of LVH on the incidence of TID was additive increasing the incidence from without LVH 10% to with LVH 55% (P<0.01). Likewise, with severe CAD, the incidence of TID rose from in patient without diabetes 4% to in those with diabetes 86% (P<0.01). Transient ischemic dilation of the left ventricle on Gated SPECT myocardial perfusion imaging is associated with the severe CAD, but this association is modified by LVH and DM. (authors)

  3. Apolipoprotein E polymorphism and acute ischemic stroke: a diffusion- and perfusion-weighted magnetic resonance imaging study.

    Science.gov (United States)

    Liu, Yawu; Laakso, Mikko P; Karonen, Jari O; Vanninen, Ritva L; Nuutinen, Juho; Soimakallio, Seppo; Aronen, Hannu J

    2002-11-01

    Diffusion- and perfusion-weighted magnetic resonance imaging (MRI) was used to study the putative effects of apolipoprotein E (ApoE) polymorphism in stroke. Thirty-one patients with acute stroke, comparative for age and gender were scanned, nine of whom were ApoE allele epsilon 4 carriers. Initially, less than 24 hours from the onset of stroke, the epsilon 4 carriers had significantly smaller volumes of hypoperfusion on relative cerebral blood volume map (P = 0.001), and smaller infarct volumes (P = 0.008) compared with the noncarriers. By day 8, this difference in the infarct volumes had disappeared, suggesting relatively enhanced infarct growth. On average, the total infarct volume increased 145% of the initial infarct volume in the epsilon 4 carriers, and 84% in the noncarriers. There were strong correlations between the imaging findings and clinical status initially and with the outcome 3 months after the stroke in the epsilon 4 noncarriers, but, with a single exception at acute phase, a lack thereof in the epsilon 4 carriers. These patterns were virtually similar in a subgroup of patients with middle cerebral artery stroke. These data support the hypothesis of increased general vulnerability of the brain in the epsilon 4 carriers. Thus, the effects of ApoE polymorphism should be accounted for when interpreting diffusion- and perfusion-weighted MRI studies, particularly if predicting lesion growth. PMID:12439291

  4. Evidence for myocardial CT perfusion imaging in the diagnosis of hemodynamically significant coronary artery disease

    OpenAIRE

    Sun, Zhonghua

    2015-01-01

    This editorial discusses a recent paper published in the August issue of Radiology about the diagnostic value of myocardial computer tomography (CT) perfusion imaging in the detection of hemodynamically significant coronary stenosis when compared to single-photon emission CT (SPECT) imaging based on a secondary analysis of CORE320 study. Three aspects including high diagnostic sensitivity of CT perfusion imaging, moderate specificity of SPECT imaging and lack of use of attenuation correction ...

  5. Myocardial first-pass perfusion imaging with hybrid-EPI: frequency-offsets and potential artefacts

    OpenAIRE

    Ferreira Pedro F; Gatehouse Peter D; Firmin David N

    2012-01-01

    Abstract Background First-pass myocardial perfusion is often imaged with a tailored hybrid centric interleaved echo-planar-imaging sequence, providing rapid image acquisition with good contrast enhancement. The centric interleaved phase-encode order minimises the effective time-of-echo but it is sensitive to frequency-offsets. This short article aims to show possible artefacts that might originate with this sequence, in the context of first-pass perfusion imaging, when frequency-offsets are p...

  6. Functional MRI procedures in the diagnosis of brain tumors. Perfusion- and diffusion-weighted imaging

    International Nuclear Information System (INIS)

    Despite the increased diagnostic accuracy of contrast material enhanced MR imaging, specification and grading of brain tumors are still only approximate at best: neither morphology, nor relaxation times or contrast material enhancement reliably predict tumor histology or tumor grade. As histology and tumor grade strongly influence which therapy concept is chosen, a more precise diagnosis is mandatory. With diffusion- and perfusion-weighted MR imaging (DWI, PWI) it is now possible to obtain important information regarding the cellular matrix and the relative regional cerebral blood volume (rrCBV) of brain tumors, which cannot be obtained with standard MR techniques. These dynamic-functional imaging techniques are very useful in the preoperative diagnosis of gliomas, lymphomas, and metastases, as well as in the differentiation of these neoplastic lesions from abscesses, atypical ischemic infarctions, and tumor-like manifestations of demyelinating disease. Additionally, they appear suitable for determining glioma grade and regions of active tumor growth which should be the target of stereotactic biopsy and therapy. After therapy these techniques are helpful to better assess the tumor response to therapy, possible therapy failure and therapy complications such as radiation necrosis. (orig.)

  7. Mr imaging and mr spectroscopy of brain metastases by mr perfusion

    International Nuclear Information System (INIS)

    In follow-up examinations of irradiated brain metastases conventional contrast-enhanced morphological MR imaging is often unable to distinguish between transient radiation effects, radionecrosis, and tumor recurrence. To evaluate changes of relative cerebral blood flow (rCBF) in irradiated brain metastases arterial spin-labeling techniques (ASL) were applied and compared to the outcome of 1H MR spectroscopy and spectroscopic imaging (1H MRS, SI). Patients and methods In 2 patients follow-up examinations of irradiated brain metastases were performed on a 1.5-T tomograph (average single dose: 20 Gy/80% isodose). Relative CBF values of gray matter (GM), white matter (WM), and metastases (Met) were measured by means of the ASL techniques ITS-FAIR and Q2TIPS. 1H MRS was performed with PRESS 1500/135. In both patients with initially hyperperfused metastases (Met/GM >1) the reduction of rCBF after stereotactic radiosurgery indicated response to treatment - even if the contrast-enhancing region increased - while increasing rCBF values indicated tumor progression. The findings were confirmed by 1H MRS, SI and subsequent follow-up. The ASL techniques ITS-FAIR and Q2TIPS are able to monitor changes of rCBF in irradiated brain metastases. The two cases imply a possible role for ASL-MR perfusion imaging and 1H MR spectroscopy in differentiating radiation effects from tumor progression. (orig.)

  8. Serial magnetic resonance imaging of evolving focal cerebral ischemia in the CAT

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) is recognized as a sensitive medium for detecting lesions within the central nervous system. Three cats were scanned under light pentobarbital anesthesia using various MRI techniques before and after right middle cerebral artery (MCA) occlusion. Scanning began as early as four minutes after MCA occlusion and continued 8 to 10 hours. The animals were subsequently perfused with a colloidal carbon and phosphate buffered formalin. Brains were removed and sliced for histopathologic examination. The sharpest images were produced with a single spin-echo, multi-slice technique using a 0.6 Tesla (T) FIELD, 0.4 cm slice thickness, and a surface coil. Changes were apparent within 1 hr after MCA occlusion with T2 weighting (TR 2000 msec, TE 120 msec). Increased signal with this technique correlated with areas of decreased colloidal carbon perfusion. One animal with a large cortical infarction showed increased cortical signal at the time of the first MRI scan completed in the first 20 min. An animal with only mild cortical changes and severe ischemic changes in the dorsal thalamus nuclei had similar MRI results. T1 weighted images (TR 500 msec, TE 30 msec) revealed changes in hemispheric contour possibly corresponding to edema at 4 hours post occlusion. One animal imaged with almost double the slice thickness (0.75 cm) and with a 1.5 T field showed poor image quality using the above techniques but without a surface coil. MRI is sensitive in detecting changes due to cerebral ischemia within 30 minutes of onset. Increased MRI signal correlated with areas of decreased colloidal carbon perfusion, demonstrated at later times

  9. Transient ischemic stunning of the myocardium in stress thallium-201 gated SPET myocardial perfusion imaging: segmental analysis of myocardial perfusion, wall motion and wall thickening changes

    International Nuclear Information System (INIS)

    Prolonged and persistent myocardial stunning has recently been demonstrated using technetium-99m sestamibi gated single-photon emission tomography (SPET) myocardial perfusion imaging post exercise or pharmacological stress test. In this study, we investigated the early postischemic transient myocardial stunning on early and delayed poststress thallium-201 gated SPET myocardial perfusion imaging using segmental wall motion (WM) and wall thickening (WT) analysis. A total of 1,680 segments from 84 patients' studies (53 men and 31 women, mean age 60 years) were evaluated on both early and delayed thallium-201 gated SPET treadmill exercise (59) or dobutamine stress (25) myocardial perfusion imaging. Semiquantitative analysis of perfusion, WM and WT in all segments was performed by two observers. Segments were classified according to changes in WM and WT between early and delayed images into normal, fixed abnormality, or improved abnormality (transient stunning), and were further classified according to changes in perfusion into normal, fixed defects, or ischemic. There were significant correlations between perfusion and WM, perfusion and WT, and WM and WT segmental scores on both early and delayed images. Transient stunning was seen significantly (P201Tl myocardial perfusion imaging using WM and WT was comparable, and results correlated well with the myocardial perfusion assessment. Early transient myocardial stunning was frequently observed in ischemic segments and was related to the severity of myocardial ischemia. (orig.)

  10. Advances in the imaging of cerebral aneurysm inflammation

    Directory of Open Access Journals (Sweden)

    Michael R Levitt

    2015-06-01

    Full Text Available Cerebral aneurysm formation, growth and rupture are thought to be the result of a complex interaction between cerebrovascular hemodynamics and pathobiology. Recently, new evidence has emerged regarding the role of inflammation in the walls of cerebral aneurysms. Noninvasive methods to characterize the degree of inflammation in aneurysms could enable clinicians to estimate the risk of future aneurysm growth and rupture, influencing treatment. This review examines emerging techniques of imaging inflammatory biomarkers in cerebral aneurysms.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-02-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-15

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

  16. Characteristics of Brain Perfusion in Patients of Parkinson's Disease

    International Nuclear Information System (INIS)

    It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9±6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4±9.2 y/o) as normal controls who had no past illness history were performed 99mTc-HMPAO brain perfusion SPECT and neuropsychological test. At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood

  17. Cerebral infarction mimicking brain tumor on Tc-99m tetrofosmin brain SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soon [College of Medicine, Dongguk Univ., Gyeongju (Korea, Republic of); Zeon, Seok Kil; Won, Kyoung Sook [School of Medicine, Keimyung Univ., Daegu (Korea, Republic of)

    2004-06-01

    A 43-year-old man was presented with persistent headache for two weeks. T2 weighted MR imaging showed high signal intensity with surrounding edema in the left frontal lobe. These findings were considered with intracranial tumor such as glioma or metastasis. Tc-99m tetrofosmin SPECT showed focal radiotracer accumulation in the left frontal lobe. The operative specimen contained cerebral infarction with organizing leptomeningeal hematoma by pathologist. Another 73-year-old man was hospitalized for chronic headache. Initial CT showed ill-defined hypodensity with mass effect in the right parietal lobe. Tc-99m tetrofosmin SPECT showed focal radiotracer uptake in the right parietal lobe. These findings were considered with low-grade glioma or infarction. Follow-up CT after 5 months showed slightly decreased in size of low density in the right parietal lobe, and cerebral infarction is more likely than others. Tc-99m tetrofosmin has been proposed as a cardiotracer of myocardial perfusion imaging and an oncotropic radiotracer. Tc-99 tetrofosmin SPECT image provides a better attractive alternative agent than TI-201 as a tumor-imaging agent, with characteristics such as high-energy flux, short half-life, favorable biodistribution, dosimetry and lower background radioactivity. We have keep in mind on the analysis of Tc-99m tetrofosmin imaging when cerebral infarction is being differentiated from brain tumor.

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

    Science.gov (United States)

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

    2015-05-30

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

  19. Application of contrast-enhanced perfusion MR imaging in patients with subclinical hepatic encephalopathy

    International Nuclear Information System (INIS)

    Objective: To investigate the perfusion pattern of the brain in patients with subclinical hepatic encephalopathy (SHE) by using MRI perfusion technique. Methods: Twelve patients with SHE diagnosed by neuropsychologic tests and 10 age and education-matched healthy volunteers accepted examinations on a 1.5 T MR scanner. The scanning protocol included conventional brain scan and dynamic susceptibility contrast enhanced perfusion MR imaging. Using the MGH perfusion software, the parameter maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were created. Bilateral head of caudate nucleus, globus pallidus, putamen, thalamus were selected as regions of interest (ROI), and ipsilateral white matter of frontal lobe was used as a reference. The ratios (ROI versus ipsilateral white matter in frontal lobe) in patient group were calculated and compared with those in the control group. Results: In SHE group, CBV ratio of head of caudate nucleus, globus pallidus, putamen, thalamus was 1.32±0.25, 1.19±0.46, 1.51±0.20, and 1.69±0.53, respectively, CBF ratio was 1.64±0.50, 1.61±0.65, 2.06±0.61, and 2.23±0.75, respectively, and MTT ratio was 0.83±0.17, 0.76±0.20, 0.78±0.19, and 0.78±0.17, respectively. CBV ratio in control group was 1.32±0.33, 1.02±0.29, 1.44±0.37, and 1.66±0.57, respectively, CBF ratio was 1.36±0.24, 1.08±0.28, 1.55±0.51, and 1.58 ±0.64, respectively, and MTT ratio was 0.95±0.18, 0.91±0.19, 0.93±0.15, and 0.93±0.13, respectively. CBF increased in SHE group compared with that in control group, and statistical increase can be detected in left globus pallidus (P<0.05). MTT reduced in SHE group, and statistical reduction can be detected in bilateral thalamus and right head of caudate nucleus (P<0.05). CBV had no statistical change in SHE patients. Conclusion: The increasing CBF and decreasing MTT in basal ganglion and thalamus could be identified in patients with SHE. CBF increase was compatible with the

  20. Local cortical hypoperfusion imaged with CT perfusion during postictal Todd's paresis

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, Marlon S.; Binder, Devin K. [University of California, Department of Neurological Surgery, Irvine, CA (United States); Smith, Wade S. [University of California, Department of Neurology, San Francisco, CA (United States); Wintermark, Max; Dillon, William P. [University of California, Department of Radiology, San Francisco, CA (United States)

    2008-05-15

    Postictal ('Todd's') paralysis, or 'epileptic hemiplegia,' is a well-known complication of focal or generalized epileptic seizures. However, it is unclear whether the pathophysiology of Todd's paralysis is related to alterations in cerebral perfusion. We report CT perfusion findings in a patient presenting with postictal aphasia and right hemiparesis. A 62-year-old woman with a history of alcohol abuse, closed head injury and posttraumatic epilepsy, presented with acute onset aphasia and right hemiparesis. A non-contrast head CT scan demonstrated no acute hemorrhage. Left hemispheric ischemia was suspected, and the patient was considered for acute thrombolytic therapy. MRI revealed a subtle increase in signal intensity involving the left medial temporal, hippocampal and parahippocampal regions on both T2-weighted FLAIR and diffusion-weighted sequences. CT angiography and CT perfusion study were performed. The CT perfusion study and CT angiography demonstrated a dramatic reduction in cerebral blood flow and blood volume involving the entire left hemisphere, but with relative symmetry of mean transit time, ruling out a large vessel occlusion. Clinical resolution of the aphasia and hemiparesis occurred within a few hours, and correlated with normalization of perfusion to the left hemisphere (detected by MR perfusion). This unique case is the first in which clinical evidence of Todd's paralysis has been correlated with reversible postictal hemispheric changes on CT and MR perfusion studies. This is important because CT perfusion study is being used more and more in the diagnosis of acute stroke, and one needs to be careful to not misinterpret the data. (orig.)

  1. Local cortical hypoperfusion imaged with CT perfusion during postictal Todd's paresis

    International Nuclear Information System (INIS)

    Postictal (''Todd's'') paralysis, or ''epileptic hemiplegia,'' is a well-known complication of focal or generalized epileptic seizures. However, it is unclear whether the pathophysiology of Todd's paralysis is related to alterations in cerebral perfusion. We report CT perfusion findings in a patient presenting with postictal aphasia and right hemiparesis. A 62-year-old woman with a history of alcohol abuse, closed head injury and posttraumatic epilepsy, presented with acute onset aphasia and right hemiparesis. A non-contrast head CT scan demonstrated no acute hemorrhage. Left hemispheric ischemia was suspected, and the patient was considered for acute thrombolytic therapy. MRI revealed a subtle increase in signal intensity involving the left medial temporal, hippocampal and parahippocampal regions on both T2-weighted FLAIR and diffusion-weighted sequences. CT angiography and CT perfusion study were performed. The CT perfusion study and CT angiography demonstrated a dramatic reduction in cerebral blood flow and blood volume involving the entire left hemisphere, but with relative symmetry of mean transit time, ruling out a large vessel occlusion. Clinical resolution of the aphasia and hemiparesis occurred within a few hours, and correlated with normalization of perfusion to the left hemisphere (detected by MR perfusion). This unique case is the first in which clinical evidence of Todd's paralysis has been correlated with reversible postictal hemispheric changes on CT and MR perfusion studies. This is important because CT perfusion study is being used more and more in the diagnosis of acute stroke, and one needs to be careful to not misinterpret the data. (orig.)

  2. Functional and perfusion magnetic resonance imaging at 3 tesla

    CERN Document Server

    Klarhoefer, M

    2001-01-01

    This thesis deals with the development and optimization of fast magnetic resonance imaging (MRI) methods for non-invasive functional studies of the human brain and perfusion imaging on a 3 Tesla (T) whole body NMR system. The functional MRI (fMRI) experiments performed showed that single-shot multi-echo EPI and spiral imaging techniques provide fast tools to obtain information about T2* distributions during functional activation in the human brain. Both sequences were found to be useful in the separation of different sources contributing to the functional MR signal like inflow or susceptibility effects in the various vascular environments. An fMRI study dealing with the involvement of prefrontal brain regions in movement preparation lead to inconsistent results. It could not be clarified if these were caused by problems during a spatial normalization process of the individual brains or if the functional paradigm, using very short inter-stimulus intervals, was not suited for the problem investigated. Blood flo...

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

    International Nuclear Information System (INIS)

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

  4. Aid in the detection of myocardial perfusion abnormality utilizing SPECT atlas and images registration: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Padua, Rodrigo Donizete Santana de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Div. de Cardiologia]. E-mail: rodrigo_dsp@hcrp.fmrp.usp.br; Oliveira, Lucas Ferrari de [Universidade Federal de Pelotas (UFPel), RS (Brazil). Inst. de Fisica e Matematica. Dept. de Tecnologia da Informacao; Marques, Paulo Mazzoncini de Azevedo [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Groote, Jean-Jacques Georges Soares de [Instituto de Ensino Superior COC, Ribeirao Preto, SP (Brazil). Lab. of Artifical Intelligence and Applications; Castro, Adelson Antonio de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina; Ana, Lauro Wichert [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Simoes, Marcus Vinicius [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina. Divisao de Cardiologia

    2008-11-15

    To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observe. The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended. (author)

  5. Aid in the detection of myocardial perfusion abnormality utilizing SPECT atlas and images registration: preliminary results

    International Nuclear Information System (INIS)

    To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observe. The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended. (author)

  6. Evaluation of myocardial involvement in Duchenne's progressive muscular dystrophy with thallium-201 myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. A qualitative analysis was performed from five projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in the LV posterolateral or posterior wall (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle involvements or thoracic deformities assessed by transmission computed tomography. Extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. Progression of the myocardial scintigraphic abnormalities were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies over 2 to 3 years. It was concluded that thallium myocardial perfusion imaging is a useful clinical technique to assess myocardial involvement in Duchenne's progressive muscular dystrophy. (author)

  7. Regional assessment of treatment in lung cancer using lung perfusion and ventilation images

    International Nuclear Information System (INIS)

    In 30 patients with lung cancer undergoing non-surgical treatment, we performed perfusion lung imaging using 99mTc-MAA and inhalation lung studies using Technegas before and after treatment and evaluated regional perfusion and ventilation status in the lung regions where bronchogenic carcinoma was located. Regional ventilation status was preserved rather than perfusion counterpart (V>P) in 18 patients (18/30=60.0%) before treatment, while the former was better than the latter in 27 patients (27/30=90.0%) after treatment, indicating that regional ventilation status improved more significantly than regional perfusion counterpart after treatment (P=0.005). We also classified the therapeutic effect for regional perfusion and ventilation status as improved, unchanged, or worsened, respectively; improvement in regional perfusion status was observed in 17 patients (56.7%) and that in regional ventilation status in 24 patients (80.0%). There was a statistically significant correlation between improved regional perfusion and ventilation status (P=0.0018) when therapeutic effect was recognized. The patients who showed improvement in regional perfusion status after treatment always showed improved regional ventilation status, but 7 patients showed either unchanged or worsened regional perfusion status after treatment, although regional ventilation status was improved. In conclusion the pulmonary vascular beds seem more vulnerable to bronchogenic carcinoma and improvement in regional perfusion status was revealed to be more difficult than that in regional ventilation status after treatment. (author)

  8. Kinetic assessment of manganese using magnetic resonance imaging in the dually perfused human placenta in vitro.

    OpenAIRE

    Miller, R.K.; Mattison, D.R.; Panigel, M.; Ceckler, T; Bryant, R; Thomford, P

    1987-01-01

    The transfer and distribution of paramagnetic manganese was investigated in the dually perfused human placenta in vitro (using 10, 20, 100 microM Mn with and without 54Mn) using magnetic resonance imaging (MRI) and conventional radiochemical techniques. The human placenta concentrated 54Mn rapidly during the first 15 min of perfusion and by 4 hr was four times greater than the concentrations of Mn in the maternal perfusate, while the concentration of Mn in the fetal perfusate was 25% of the m...

  9. Clinical applications of brain perfusion imaging with 99mTc-HM-PAO

    International Nuclear Information System (INIS)

    200 patients with central nervous system diseases were studied with 99mTc-HM-PAO and SPECT, including Parkinson's disease (PD) 47, Vascular headache 69, CVD 34, Epilepsy 26, Head truma 10, Brain tumor 5 and other 9 cases. Part of them have been compared with the results of MRI, X-CT and EEG. The positivity of SPECT in PD is 61.7% with decrease perfusion in local area of cerebram and basal ganglia and only 4 cases had lower perfusion in cerebellum; in headache is 46.4%, showing variable perfusion patterns; in CVD is 79.4% with decrease perfusion, luxury perfusion and the phenomenon of 'diaschsis'. In epilepsy, the abnormal foci mostly localize in temporal lobe and have close relation to the results of EEG. In brain tumor it also denotes decreased uptake of tracer. The clinicl singnificance of brain perfusion imaging with 99mTc-HM-PAO was discussed

  10. Myocardial perfusion image with attentuation correction by X-ray in detection of CAD

    International Nuclear Information System (INIS)

    Purpose: Attenuation correction by transmission image has been demonstrated to be a good method to improve the image quality and the diagnostic accuracy of myocardial perfusion. The purpose of this research is to evaluate the myocardial peffusion image with attenuation correction by X-ray. Methods: Twenty-six patients suspected coronary artery disease (CAD) underwent stress-rest 99mTc-MIBI myocardial perfusion image (MPI) with and without X-ray transmission image by an SPECT/CT system, and coronary angiography (CAG). The MPIs were reconstructed into two types: with and without X-ray attenuation correction (AC) and analyzed by nuclear physician. Results: There were 12 patients and 14 patients with and without CAD, respectively. Image quality of MPI with AC is much better than that of MPI without AC. The sensitivity MPI with and without AC in detection of CAD were 83.3% and 91.7%, respectively, p value is 0.537. Both specificities of MPI with and without AC in excluding to CAD were 100%. However, MPI with AC overestimate myocardial perfusion abnormality in anterior wall of let ventricle and underestimate that in posterior wall, compared with MPI without AC. Conclusion: X-ray attenuation correction can obviously improve the image quality of myocardial perfusion image. Myocardial perfusion image with X-ray attenuation correction has comparable diagnostic accuracy to that myocardial perfusion image without attenuation correction. However, its clinical value in detection of coronary artery disease is needed more researches. (authors)

  11. Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging

    OpenAIRE

    Lauzier, Pascal Thériault; Jie TANG; Speidel, Michael A.; Chen, Guang-Hong

    2012-01-01

    Purpose: To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a di...

  12. Acute cerebral vascular accident associated with hyperperfusion

    International Nuclear Information System (INIS)

    Cerebral radionuclide angiography can demonstrate decreased or normal radioactivity in the affected region during the arterial phase in patients who have sustained a cerebral vascular accident and thus enhances the diagnostic specificity of the static brain image. In an occasional patient, however, a seemingly paradoxical pattern of regional hyperperfusion with a return to normal or subnormal perfusion following the acute phase has been observed. This phenomenon, called luxury perfusion, has been defined using intra-arterial 133Xe for semiquantitative cerebral blood flow measurements and should be kept in mind as a potentially misleading cerebral imaging pattern

  13. Strategies for Reducing Respiratory Motion Artifacts in Renal Perfusion Imaging with Arterial Spin Labeling

    OpenAIRE

    Robson, Philip M.; Madhuranthakam, Ananth J.; Dai, Weiying; Pedrosa, Ivan; Rofsky, Neil M.; Alsop, David C.

    2009-01-01

    Arterial Spin Labeling (ASL) perfusion measurements may have many applications outside the brain. In the abdomen, severe image-artifacts can arise from motions between acquisitions of multiple signal averages in ASL, even with single-shot image-acquisition. Background suppression and respiratory motion synchronization techniques can be used to ameliorate these artifacts. Two separate in-vivo studies of renal perfusion imaging using pulsed-continuous ASL were performed. The first study assesse...

  14. Cerebral MR imaging of malignant melanoma

    International Nuclear Information System (INIS)

    Melanoma is the third leading cancer entity to metastasize to the central nervous system (CNS) after lung and breast cancer. This is often an early event in the disease course and limits survival. Metastasis in the CNS is the cause of death in 10-40 % of melanoma patients and the incidence of brain metastasis is even higher (50-75 %). Cerebral metastases are commonly found in the subcortical white matter. The signal characteristics can vary substantially and may change over time due to hemorrhages or the accumulation of melanin and paramagnetic ions. It is not yet clear whether novel targeted therapies (e.g. immunotherapy and kinase inhibitors) alter imaging characteristics. Also immune-related side effects, such as hypophysitis (in approximately 5 % of patients receiving ipilimumab therapy) or granulomatous disease (neurosarcoid) can occur. Melanoma metastases are usually hyperdense in computed tomography (CT). In magnetic resonance imaging (MRI) T2-weighted (T2-w) fluid-attentuated inversion recovery (FLAIR) and T1-w sequences (with and without i.v. contrast) should be obtained. Coronal and axial imaging planes should be scanned to cross-correlate findings. Susceptibility-weighted imaging is a new sensitive method to detect melanoma metastases. Approximately 66 % of melanoma metastases show intratumoral susceptibility signals (ITSS). This sets them apart from other metastases (e.g. lung and breast cancer show less ITSSs, specificity approximately 81-96 %). Diffusion imaging plays no major role in melanoma brain imaging. Susceptibility-weighted imaging increases the sensitivity to detect metastases but lacks specificity. Differentiating metastases, microbleeding or calcification can be impossible. It is controversial how to interpret susceptibility signals without correlative signs on other sequences (differential diagnosis: metastasis, microbleeding and calcification). CNS metastases are common in melanoma. MRI screening starting in stage IIc should be considered

  15. Simulation of realistic abnormal SPECT brain perfusion images: application in semi-quantitative analysis

    International Nuclear Information System (INIS)

    Simulation is useful in the validation of functional image analysis methods, particularly when considering the number of analysis techniques currently available lacking thorough validation. Problems exist with current simulation methods due to long run times or unrealistic results making it problematic to generate complete datasets. A method is presented for simulating known abnormalities within normal brain SPECT images using a measured point spread function (PSF), and incorporating a stereotactic atlas of the brain for anatomical positioning. This allows for the simulation of realistic images through the use of prior information regarding disease progression. SPECT images of cerebral perfusion have been generated consisting of a control database and a group of simulated abnormal subjects that are to be used in a UK audit of analysis methods. The abnormality is defined in the stereotactic space, then transformed to the individual subject space, convolved with a measured PSF and removed from the normal subject image. The dataset was analysed using SPM99 (Wellcome Department of Imaging Neuroscience, University College, London) and the MarsBaR volume of interest (VOI) analysis toolbox. The results were evaluated by comparison with the known ground truth. The analysis showed improvement when using a smoothing kernel equal to system resolution over the slightly larger kernel used routinely. Significant correlation was found between effective volume of a simulated abnormality and the detected size using SPM99. Improvements in VOI analysis sensitivity were found when using the region median over the region mean. The method and dataset provide an efficient methodology for use in the comparison and cross validation of semi-quantitative analysis methods in brain SPECT, and allow the optimization of analysis parameters

  16. Assessment of smoking-induced impairment of pulmonary perfusion using three-dimensional SPECT images

    Energy Technology Data Exchange (ETDEWEB)

    Miyasaka, Takashi [Toho Univ., Tokyo (Japan). School of Medicine

    1997-09-01

    The effects of smoking on ventilation-perfusion lung scintigrams were investigated. The subjects comprised 40 healthy males (28 smokers and 12 nonsmokers) without a history of cardiopulmonary disease and with normal chest radiographs. After acquisition of planar images of ventilation lung scintigrams with 370 MBq of {sup 133}Xe gas, planar images and SPECT images of pulmonary perfusion flow were obtained using 185 MBq of {sup 99m}Tc-MAA. Planar imaging showed perfusion defects in only 5 smokers. In contrast, 16 subjects were found to have perfusion defects on SPECT images (p<0.05), indicating the usefulness of SPECT images in detecting minor vascular damage of the lung. Although perfusion defects were common in the smokers (p<0.05), their relationship to the BRINKMAN index was uncertain. The perfusion defects found in the smokers were nonsegmental and commonly involved the right upper lobe. Ventilation scans revealed only delayed washout of {sup 133}Xe in 4 smokers, suggesting that smoking-induced abnormal perfusion on SPECT appears earlier than impaired ventilation on scintigrams. (author)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  19. Asymptomatic cerebral infarction examined by magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    To find the real incidence and risk factors in asymptomatic cerebral infarction, a retrospective review was made on magnetic resonance (MR) images, which were obtained from 713 outpatients seen at the Geriatrics Research Institute Hospital between March and November of 1990. The criteria for asymptomatic cerebral infarction are: high signal intensity areas larger than 3 mm in diameter on T2-weighted image; no history of stroke; no neurological and psychological signs or symptoms with or without subjective symptoms. Symptomatic cerebral stroke was defined as stroke episodes associated with neurological signs and infarction lesions on CT or MR imaging. Of a total of 713 patients, 215 (30.2%) had symtomatic cerebral infarction and 384 (53.9%) had no cerebral lesions. The incidence of asymptomatic cerebral infarction increased with aging. Cerebral risk factors, i.e. hypertension, atrial fibrillation, and diabetes mellitus, were more significantly common in both symptomatic and asymptomatic groups than the normal control group. In the group of asymptomatic patients, T2-weighted images showed hyperintensity in the corona radiata in 60.9%, in the frontal lobe in 32.1%, in the semioval center in 28.8%, and in the basal ganglia in 23.7%. Periventricular hyperintensity was present in 124 of all 713 patients (17.4%). Common complaints in asymptomatic patients were headache (40.0%), dizziness (14.4%), and neck muscle contraction (9.8%). In conclusion, MR imaging may contribute to manage asymptomatic patients. (N.K.)

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

    International Nuclear Information System (INIS)

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

  1. Early detection of cerebral infarction by 31P spectroscopic imaging

    International Nuclear Information System (INIS)

    Recent advances in magnetic resonance spectroscopy permit noninvasive study of brain metabolism in vivo, 31P spectroscopic imaging being the method for evaluation of localized phosphorous metabolism. Experimentally, an ischemic-hypoxic brain insult is characterized by depletion of high energy metabolites. These changes are seen immediately after an ischemic insult. We had the opportunity of carrying out 31P spectroscopic imaging of hyperacute cerebral infarction, while MRI and CT were negative. Cerebral infarction of the middle cerebral artery territory was suggested by 31P spectroscopic imaging, which was closely consistent with a later-developing region of low density on CT. In cerebral infarction, early detection of the lesion is a useful pointer to the patient's prognosis, making 31P spectroscopic imaging a potential tool. (orig.)

  2. Optimizing ventilation-perfusion lung scintigraphy: parting with planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Reinartz, P.; Schirp, U.; Zimny, M.; Sabri, O.; Nowak, B.; Schaefer, W.; Cremerius, U.; Buell, U. [University Hospital, Aachen (Germany). Dept. of Nuclear Medicine

    2001-04-01

    Aim of the study was to introduce and verify a ventilation-perfusion (V/Q) acquisition protocol that incorporates new developments in scinitgraphy in order to allow for a more balanced comparison with other diagnostic procedures. Methods: In 103 patients suspect of having pulmonary embolism, V/Q scans were acquired exclusively with SPECT technique. Ventilation was done with ultrafine aerosol. Planar images in eight directions were reconstructed through addition of three consecutive SPECT projections. Three referees examined the scans in regard to type, localization, and extent of V/Q defects. Results: Using this protocol, significantly more defects, especially of subsegmental size, were detected (p<0.01). Sensitivity, and diagnostic accuracy were also significantly improved (p<0.01) to 0.96, and 0.99, respectively. Furthermore, kappa values were increased up to 0.82 - a relevant enhancement in the ability to precisely localize V/Q defects. Conclusion: In conclusion this protocol provides high-resolution tomographic scans as well as high-quality planar images within a short acquisition time. Due to the significant increase in lesion detection, sensitivity, diagnostic accuracy, and anatomical localization of defects, it is a substantial improvement in the diagnosis of pulmonary embolism that will put V/Q scintigraphy on a par with other tomographic methods. (orig.) [German] Ziel der Studie ist die Einfuehrung und Evaluierung eines Ventilations-Perfusions-Akquisitionsprotokolles (V/Q), das neue technische Entwicklungen beruecksichtigt und auf diese Weise einen ausgewogeneren Vergleich mit anderen tomographischen Verfahren erlaubt. Methodik: Bei 103 Patienten mit Verdacht auf Lungenembolie wurden V/Q-Akquisitionen ausschliesslich in SPECT-Technik angefertigt. Die Ventilationsstudien erfolgten dabei unter Verwendung eines ultrafeinen Aerosols. Durch Addition von jeweils drei aufeinander folgenden SPECT-Projektionen wurden planare Bilder in acht Ansichten rekonstruiert

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

    International Nuclear Information System (INIS)

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

  4. Quantitative perfusion imaging in magnetic resonance imaging; Quantitative Perfusionsbildgebung in der Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, F.G.; Gaa, T.; Zimmer, F. [Universitaet Heidelberg, Computerunterstuetzte Klinische Medizin, Medizinische Fakultaet Mannheim, Mannheim (Germany); Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M. [Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim, Mannheim (Germany)

    2016-02-15

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [German] Die Magnetresonanztomographie (MRT) zeichnet sich durch einen ueberlegenen Gewebekontrast aus, waehrend sie nichtinvasiv und frei von ionisierender Strahlung ist. Sie bietet Zugang zu Gewebe- und Organfunktion. Eine dieser funktionellen bildgebenden Verfahren ist die Perfusionsbildgebung. Mit dieser Technik koennen u. a. Gewebeperfusion und Kapillarpermeabilitaet aus dynamischen Bilddaten bestimmt werden. Perfusionsbildgebung mithilfe der MRT kann durch 2 Ansaetze, naemlich ''arterial spin labeling'' (ASL) und dynamische kontrastverstaerkte (DCE-)MRT durchgefuehrt werden. Waehrend die erste Methode magnetisch

  5. Functional Cluster Analysis of CT Perfusion Maps: A New Tool for Diagnosis of Acute Stroke?

    OpenAIRE

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

    2005-01-01

    CT perfusion imaging constitutes an important contribution to the early diagnosis of acute stroke. Cerebral blood flow (CBF), cerebral blood volume (CBV) and time-to-peak (TTP) maps are used to estimate the severity of cerebral damage after acute ischemia. We introduce functional cluster analysis as a new tool to evaluate CT perfusion in order to identify normal brain, ischemic tissue and large vessels. CBF, CBV and TTP maps represent the basis for cluster analysis applying a partitioning (k-...

  6. Comparison of technetium-99m-HMPAO and technetium-99m-ECD cerebral SPECT images in Alzheimer`s disease

    Energy Technology Data Exchange (ETDEWEB)

    Dyck, C.H. van; Lin, C.H.; Smith, E.O. [Yale Univ. School of Medicine, New Haven, CT (United States)] [and others

    1996-11-01

    SPECT has shown increasing promise as a diagnostic tool in Alzheimer`s disease (AD). Recently, a new SPECT brain perfusion agent, {sup 99m}Tc-ethyl cysteinate dimer ({sup 99m}Tc-ECD) has emerged with purported advantages in image quality over the established tracer, {sup 99m}Tc-hexamethylpropyleneamine oxime ({sup 99m}Tc-HMPAO). This research aimed to compare cerebral images for ({sup 99m}Tc-HMPAO). This research aimed to compare cerebral images for {sup 99}mTc-HMPAO and {sup 99m}Tc-ECD in discriminating patients with AD form control subjects. 51 refs., 5 figs., 3 tabs.

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

    Science.gov (United States)

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

    2014-05-01

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

  8. Contralateral thalamic hypoperfusion on brain perfusion SPECT

    International Nuclear Information System (INIS)

    Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

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

    Institute of Scientific and Technical Information of China (English)

    顾正章; 邢伟; 金真; 李科

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  11. The veracity and reproducibility of hepatic CT perfusion imaging: an animal experiment and clinical study

    International Nuclear Information System (INIS)

    Objective: To evaluate the veracity and reproducibility of quantitative measurement of hepatic blood flow with CT perfusion imaging. Methods: Twenty-one healthy adult canines were selected to perform single-section hepatic CT perfusion imaging. The scanning plain simultaneously including liver, abdominal aorta and portal vein was selected to measure the blood flow parameters and the time-density curve was obtained from the region of interest. Individual hepatic arterial perfusion and portal venous perfusion parameters were calculated by the method of deconvolution and converted to hepatic arterial blood flow and portal venous blood flow. The hepatic artery and portal venous blood flow were measured by the electromagnetic flowmeter in order to evaluate the veracity of CT perfusion imaging. The reproducibility of CT perfusion imaging in humans was assessed by three observers in two sessions in the 18 healthy volunteers. Results: The hepatic artery flow, portal venous flow and total liver flow measured by CT perfusion were (145 ± 35), (611 ± 161) and (755 ± 179)ml/min, respectively. The hepatic artery flow, portal venous flow and total liver flow measured by electromagnetic flowmeter were (127 ± 44), (637 ± 165) and (764 ± 182) ml/min, respectively. The correlation coefficients of the three parameters measured by the two measurements were 0.671, 0.828 and 0.899, respectively. Two-way ANOVA showed high concordance between the three observers or between the two measurements performed by each observer (ICC>0.9). Conclusions: CT perfusion imaging could quantify the hepatic blood flow. The accuracy is similar to electromagnetic flowmeter, and it could effectively reflect physiological or pathological hemodynamics of liver. CT perfusion is noninvasive, high reproducible and convenient, which could be widely used in clinical practice. (authors)

  12. Quantitative perfusion imaging with pulsed arterial spin labeling. A phantom study

    International Nuclear Information System (INIS)

    Pulsed arterial spin labeling (PASL) is a magnetic resonance (MR) method for measuring cerebral blood flow. Although several validation studies for PASL in animals and humans have been reported, no reports have detailed the fundamental study of PASL using a flow phantom. We compared the true and theoretical flow rates in a flow phantom to confirm the analytical validity of quantitative perfusion imaging with Q2TIPS sequence. We built a flow phantom consisting of a 40-mm diameter plastic syringe filled with plastic beads and small plastic tubes 4 mm in diameter. Gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA)-doped 8L water solution (0.1 mM) was circulated between the syringe and a tank through a plastic tube by a constant flow pump while the flow rate was adjusted between 0 and 2.61 cm/s. Q2TIPS sequence parameters were TI1=50 ms and TI2=1400 ins. Five imaging slices of 50 subtraction images were acquired sequentially in a distal-to-proximal direction using a single-shot echo planar imaging (EPI) technique. The theoretical flow rate calculated based upon the previously reported kinetic model for Q2TIPS was compared with the true flow rate. A good linear relationship was observed between the theoretical, F', and true flow rates, F, in a flow rate range of 1.43 to 1.95 cm/s (F'=1.024·F-1.915, R2=0.902). The ratio of theoretical to true flow rate was 92 (+/-) 4%. Flow rate was quantified with reasonable accuracy when the entire amount of labeled bolus within the phantom could be recovered. Our experiment confirmed the analytical validity of Q2TIPS and suggested that blood flow measurement may be feasible using the Q2TIPS pulse sequence and kinetic model of the PASL equation. (author)

  13. Schizophrenia patients differentiation based on MR vascular perfusion and volumetric imaging

    Science.gov (United States)

    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 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.

  14. Computer processsing of perfusion, ventilation, and V/Q images to highlight pulmonary embolism

    International Nuclear Information System (INIS)

    A method is described for generating regional ventilation/perfusion (V/Q) images of the lung to aid assessment of suspected pulmonary embolism, especially in patients with obstructive airways disease. The radionuclide scans used for this are stored on a computer and comprise: lung perfusion (P) with Tc-99m MAA, lung ventilation at equilibrium (E) with Xe-127, and the sum of the Xe-127 washout images (W). A functional ventilation image is calculated as V = E/W and a functional perfusion image as Q = P/E. Finally a ventilation perfusion ratio image is obtained by taking V/Q. This is normalised by a factor determined from the cumulative frequency distributions of the counts per pixel in the Q and V images so that areas which are well ventilated and perfused are given a V/Q value of 1.0. Areas with normalised V/Q values > 1.5 suggest pulmonary embolism. In 100 studies on patients with abnormal perfusion scans this method proved very helpful by assisting the recognition or exculsion of areas with abnormally high V/Q values. (orig.)

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

    International Nuclear Information System (INIS)

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

  16. Organ perfusion during voluntary pulmonary hyperinflation; a magnetic resonance imaging study.

    Science.gov (United States)

    Kyhl, Kasper; Drvis, Ivan; Barak, Otto; Mijacika, Tanja; Engstrøm, Thomas; Secher, Niels H; Dujic, Zeljko; Buca, Ante; Madsen, Per Lav

    2016-02-01

    Pulmonary hyperinflation is used by competitive breath-hold divers and is accomplished by glossopharyngeal insufflation (GPI), which is known to compress the heart and pulmonary vessels, increasing sympathetic activity and lowering cardiac output (CO) without known consequence for organ perfusion. Myocardial, pulmonary, skeletal muscle, kidney, and liver perfusion were evaluated by magnetic resonance imaging in 10 elite breath-hold divers at rest and during moderate GPI. Cardiac chamber volumes, stroke volume, and thus CO were determined from cardiac short-axis cine images. Organ volumes were assessed from gradient echo sequences, and organ perfusion was evaluated from first-pass images after gadolinium injection. During GPI, lung volume increased by 5.2 ± 1.5 liters (mean ± SD; P hyperinflation by GPI, CO and organ perfusion, including the myocardium, as well as perfusion of skeletal muscles, are reduced, and yet perfusion of the liver is maintained. Liver perfusion seems to be prioritized when CO decreases during GPI. PMID:26589331

  17. Preoperative localization of epileptic foci with SPECT brain perfusion imaging, electrocorticography, surgery and pathology

    International Nuclear Information System (INIS)

    Objective: The value of preoperative localization of epileptic foci with SPECT brain perfusion imaging was investigated. Methods: The study population consisted of 23 patients with intractable partial seizures which was difficult to control with anticonvulsant for long period. In order to preoperatively locate the epileptic foci, double SPECT brain perfusion imaging was performed during interictal and ictal stage. The foci were confirmed with electrocorticography (EcoG), surgery and pathology. Results: The author checked with EcoG the foci shown by SPECT, 23 patients had all typical spike discharge. The regions of radioactivity increase in ictal matched with the abnormal electrical activity areas that EcoG showed. The spike wave originated in the corresponding cerebrum cortex instead of hyperplastic and adherent arachnoid or tumor itself. Conclusions: SPECT brain perfusion imaging contributes to distinguishing location, size, perfusion and functioning of epileptogenic foci, and has some directive function on to making out a treatment programme at preoperation

  18. An attempt of thallium-201 myocardial perfusion imaging during transient coronary arterial occlusion by PTCA

    International Nuclear Information System (INIS)

    To evaluate the myocardial perfusion during transient coronary occlusion, we attempted to obtain the myocardial scintigraphy during percutaneous transluminal coronary angioplasty (PTCA). Tl-201 was injected at the last inflation of angioplastic balloon and occlusion was kept on for 60 sec. Planar images or SPECT were obtained immediately after PTCA. With this protocol, myocardial perfusion defects were observed during PTCA and fully redistributed 3 hours after Tl injection. Extent of ischemic lesions were almost same as that observed during exercise in two cases without collateral vessels. In a case with well visualized collateral vessels, perfusion defect was smaller in PTCA images than that in exercise stressed images. We conclude that intravenous injection of Tl-201 during PTCA is useful to assess the alteration of myocardial perfusion due to transient coronary occlusion without increasing the risk of angioplastic procedure. (author)

  19. Evaluation of the effects of rehabilitation exercise on cerebral infarction with 99Tcm-ECD SPECT brain imaging

    International Nuclear Information System (INIS)

    Objective: To investigate the therapeutic effects of motor therapy on hemiplegia with SPECT brain perfusion imaging. Methods: The study population consisted of 59 patients with cerebral infarction, and all patients were treated with motor therapy. Among them, 30 cases were assigned to undertake single bridging exercise and 29 cases passive exercise. SPECT brain perfusion imaging was performed before and after motor therapy under the same condition, and the regional cerebral blood flow (rCBF) changes were compared and analysed with visual and semi-quantitative methods; in addition, the relationship between rCBF changes and scores of Fugl-Meyer or Barthel index were also analysed. Results: After motor therapy, various degrees of radioactivity increase were compared with the pretreatment radioactivity hypoperfusion in patients with cerebral infarction, and showed that motor therapy could evidently improve rCBF of regional hypoperfusion. The posttreatment rCBF was higher than the pretreatment level (P<0.01), and the rCBF of group of single bridging was higher than that of passive exercise group. And the changes of rCBF were all significant after motor therapy. In addition, the variation of the rCBF after motor therapy was positively correlated with the variation of Fugl-Meyer and Barthel score. Conclusions: SPECT brain perfusion imaging can serve as a useful method for evaluating the effectiveness of motor therapy in cerebral infarction rehabilitation. The single bridging exercise and the passive exercise are both beneficial to brain rehabilitation, but the former improves the rCBF in lesions better than the later does

  20. MR imaging of fetal cerebral anomalies

    International Nuclear Information System (INIS)

    Background. Prenatal diagnosis of fetal brain anomalies relies mainly upon ultrasonography. However, even in the most experienced hands, the technique has limitations for some difficult diagnoses. MRI is an excellent imaging modality for the paediatric and adult brain. Objective. To assess the value of prenatal MRI when a cerebral anomaly was detected by US and where the prognosis depended on the identification of other anomalies undetectable by US, or where fetuses were at risk for a CNS lesion even when the US was normal. Materials and methods. Four hundred prenatal MRI examinations were performed since 1988, and confirmed by postnatal follow-up or pathological examination. Two-thirds of the examinations were performed after 25 weeks of gestation, one-third between 21 and 26 weeks. Fetal immobilisation was obtained by maternal premedication with flunitrazepam, administered orally 1 h before the examination. The examinations were performed on 1.5 T scanners using one or two surface coils. Results. Prenatal MRI allowed the diagnosis of serious unsuspected lesions such as neuronal migration disorders, ischaemic and haemorrhagic lesions and the abnormalities observed in tuberous sclerosis. It helped to characterise ventricular dilatation and anomalies of the corpus callosum and of the posterior fossa. Conclusions. MRI is a valuable complementary tool when prenatal US is incomplete, doubtful or limited. Prenatal MRI is particularly useful for the detection of ischaemic and haemorrhagic lesions, neuronal migration disorders and tuberous sclerosis lesions. Detection of these associated anomalies worsens the fetal prognosis, has medico-legal implications and modifies obstetric management. Normal prenatal MRI does not exclude an anomaly. (orig.)

  1. MR imaging of fetal cerebral anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Sonigo, P.C.; Carteret, M.; Brunelle, F.O. [Department of Radiology, Hopital Des Enfants Malades, Paris (France); Rypens, F.F. [Department of Radiology, Hopital Des Enfants Malades, Paris (France)]|[Department of Radiology, Hopital Erasme, Brussels (Belgium); Delezoide, A.L. [Department of Pathology, Hopital Des Enfants Malades, Paris (France)

    1998-04-01

    Background. Prenatal diagnosis of fetal brain anomalies relies mainly upon ultrasonography. However, even in the most experienced hands, the technique has limitations for some difficult diagnoses. MRI is an excellent imaging modality for the paediatric and adult brain. Objective. To assess the value of prenatal MRI when a cerebral anomaly was detected by US and where the prognosis depended on the identification of other anomalies undetectable by US, or where fetuses were at risk for a CNS lesion even when the US was normal. Materials and methods. Four hundred prenatal MRI examinations were performed since 1988, and confirmed by postnatal follow-up or pathological examination. Two-thirds of the examinations were performed after 25 weeks of gestation, one-third between 21 and 26 weeks. Fetal immobilisation was obtained by maternal premedication with flunitrazepam, administered orally 1 h before the examination. The examinations were performed on 1.5 T scanners using one or two surface coils. Results. Prenatal MRI allowed the diagnosis of serious unsuspected lesions such as neuronal migration disorders, ischaemic and haemorrhagic lesions and the abnormalities observed in tuberous sclerosis. It helped to characterise ventricular dilatation and anomalies of the corpus callosum and of the posterior fossa. Conclusions. MRI is a valuable complementary tool when prenatal US is incomplete, doubtful or limited. Prenatal MRI is particularly useful for the detection of ischaemic and haemorrhagic lesions, neuronal migration disorders and tuberous sclerosis lesions. Detection of these associated anomalies worsens the fetal prognosis, has medico-legal implications and modifies obstetric management. Normal prenatal MRI does not exclude an anomaly. (orig.) With 19 figs., 33 refs.

  2. Value of multidetector computed tomography evaluation of myocardial perfusion in the assessment of ischemic heart disease: comparison with nuclear perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kachenoura, Nadjia; Lodato, Joseph A.; Bardo, Dianna M.E.; Newby, Barbara; Lang, Roberto M.; Mor-Avi, Victor [University of Chicago Medical Center, Chicago, IL (United States); Gaspar, Tamar; Gips, Sarah; Peled, Nathan [Lady Davis Carmel Medical Center, Haifa (Israel)

    2009-08-15

    MDCT-derived myocardial perfusion has not yet been validated against accepted standards. We developed a technique for quantification of myocardial perfusion from MDCT images and studied its diagnostic value against SPECT myocardial perfusion imaging (MPI). Ninety-eight patients were studied. Abnormal perfusion was detected by comparing normalized segmental x-ray attenuation against values obtained in 20 control subjects. Disagreement with resting MPI was investigated in relationship to MDCT image quality, severity of MPI abnormalities, and stress MPI findings. Resting MPI detected mild or worse abnormalities in 20/78 patients. MDCT detected abnormalities in 15/20 patients (sensitivity of 0.75). Most abnormalities missed by MDCT analysis were graded as mild on MPI. Additional abnormalities found in 16/78 patients were not confirmed on resting MPI (specificity of 0.72). However, 8 of these 16 apparently false positive MDCT perfusion tests had abnormal stress MPI; of these 8 patients, 7 had optimal MDCT image quality, while in 6/8 remaining patients, image quality was suboptimal. When compared with resting MPI, MDCT detected perfusion abnormalities with high accuracy. Moreover, half of MDCT perfusion abnormalities not confirmed by resting MPI were associated with abnormal stress MPI. Importantly, this information can be obtained without additional radiation dose or contrast agent. (orig.)

  3. Non-negative constraint for image-based breathing gating in ultrasound hepatic perfusion data

    Science.gov (United States)

    Wu, Kaizhi; Ding, Mingyue; Chen, Xi; Deng, Wenjie; Zhang, Zhijun

    2015-12-01

    Images acquired during free breathing using contrast enhanced ultrasound hepatic perfusion imaging exhibits a periodic motion pattern. It needs to be compensated for if a further accurate quantification of the hepatic perfusion analysis is to be executed. To reduce the impact of respiratory motion, image-based breathing gating algorithm was used to compensate the respiratory motion in contrast enhanced ultrasound. The algorithm contains three steps of which respiratory kinetics extracted, image subsequences determined and image subsequences registered. The basic performance of the algorithm was to extract the respiratory kinetics of the ultrasound hepatic perfusion image sequences accurately. In this paper, we treated the kinetics extracted model as a non-negative matrix factorization (NMF) problem. We extracted the respiratory kinetics of the ultrasound hepatic perfusion image sequences by non-negative matrix factorization (NMF). The technique involves using the NMF objective function to accurately extract respiratory kinetics. It was tested on simulative phantom and used to analyze 6 liver CEUS hepatic perfusion image sequences. The experimental results show the effectiveness of our proposed method in quantitative and qualitative.

  4. Carotid color doppler flow imaging of cerebral infarction in Korea

    International Nuclear Information System (INIS)

    Until now, there have been no reported document concerning the incidence of atheroma of the carotid artery associated with occlusive cerebrovascular disease in Korea. We tried to identify atheroma of the carotid artery in acute cerebral infarction patients using duplex sonography and color flow imaging. Recent reports state that duplex sonography and color flow imaging were reported to be more accurate and safer non-invasive method of detecting carotid atheroma than carotid angiography. Atheromas were detected in 41(56%) out of total of 73 acute cerebral infarction patients. However, other conditions such as hypertension (37/73), cardiac problems(22/73), diabetes mellitus(10/73), and conditions of unknown etiologiest (13/73) were also observed in association with acute cerebral infarction. We conclude that carotid atheroma presents as the most important cause of cerebral infraction in Korea

  5. Carotid color doppler flow imaging of cerebral infarction in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Lee, Eun Joo; Yang, Hee Chul; Choi, Il Saing; Lee, Myung Sik; Lee, Byung In [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1990-10-15

    Until now, there have been no reported document concerning the incidence of atheroma of the carotid artery associated with occlusive cerebrovascular disease in Korea. We tried to identify atheroma of the carotid artery in acute cerebral infarction patients using duplex sonography and color flow imaging. Recent reports state that duplex sonography and color flow imaging were reported to be more accurate and safer non-invasive method of detecting carotid atheroma than carotid angiography. Atheromas were detected in 41(56%) out of total of 73 acute cerebral infarction patients. However, other conditions such as hypertension (37/73), cardiac problems(22/73), diabetes mellitus(10/73), and conditions of unknown etiologiest (13/73) were also observed in association with acute cerebral infarction. We conclude that carotid atheroma presents as the most important cause of cerebral infraction in Korea.

  6. Efficacy of dynamic CT perfusion imaging in conjunction with three dimensional CT angiography for the evaluation of acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Nakaguchi, Hiroshi; Teraoka, Akira; Adachi, Shinobu; Yanagibashi, Kazutaka [Teraoka Memorial Hospital, Shinichi, Hiroshima (Japan)

    2003-01-01

    Through the use of a high-speed spiral CT scanner (GEMedical HiSpeedZX/i), CT/P/A technique, where conventional CT, CT perfusion imaging (CTP) and CT angiography (CTA) are consecutively performed, can now be performed with an imaging time of 90 seconds and a total contrast medium volume of 100 ml. A prospective clinical study was performed to ascertain the effectiveness of CT/P/A in diagnosing acute ischemic strokes. Twenty-nine consecutive patients of Teraoka Memorial Hospital suspected of suffering from the occlusion or constriction of cerebral arteries and who underwent CT/P/A within 3 hours from the onset served as subjects. The sensitivity, specificity, or Odds ratio of CTP and CTA in detecting lesions that caused cerebral infarction was calculated. CTP detected a hypoperfusion area with a sensitivity, specificity, and Odds ratio of 80%, 64%, and 7.2. The sensitivity in lobar infarcts, white matter infarcts, basal ganglia infarcts, and brainstem infarcts was 100%, 100%, 100%, 0% (p=0.0022). The sensitivity and Odds ratio of CT/P/A in cerebral infarcts differed according to the diameter of the infarcts. That with infarcts of 10 mm or more was 91%, 20. That with infarcts smaller than 10 mm was 50%, 2. CTA detected arterial lesions that caused cerebral ischemic attack with a sensitivity of 94% and specificity of 90%. The examination time for CT/P/A was 18 minutes, total radiation time being 90 seconds. Although CT/P/A was ineffective for the diagnosis of brainstem infarcts and lesions smaller than 10 mm, CT/P/A was useful in detecting moderate-sized hypoperfusion areas and arterial lesions three-dimensionally before an infarct is completed. (author)

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

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  8. Noninvasive quantification of myocardial perfusion heterogeneity by Markovian analysis in SPECT nuclear imaging

    International Nuclear Information System (INIS)

    Cardiovascular diseases are the leading cause of mortality worldwide, and third of these deaths are caused by coronary artery disease and rupture of vulnerable atherosclerotic plaques. The heterogeneous alteration of the coronary microcirculation is an early phenomenon associated with many cardiovascular risk factors that can strongly predict the subsequent development of coronary artery disease, and lead to the appearance of myocardial perfusion heterogeneity. Nuclear medicine allows the study of myocardial perfusion in clinical routine through scintigraphic scans performed after injection of a radioactive tracer of coronary blood flow. Analysis of scintigraphic perfusion images currently allows the detection of myocardial ischemia, but the ability of the technique to measure the perfusion heterogeneity in apparently normally perfused areas is unknown. The first part of this thesis focuses on a retrospective clinical study to determine the feasibility of myocardial perfusion heterogeneity quantification measured by Thallium-201 single photon emission computed tomography (SPECT) in diabetic patients compared with healthy subjects. The clinical study has demonstrated the ability of routine thallium-201 SPECT imaging to quantify greater myocardial perfusion heterogeneity in diabetic patients compared with normal subjects. The second part of this thesis tests the hypothesis that the myocardial perfusion heterogeneity could be quantified in small animal SPECT imaging by Thallium-201 and/or Technetium-99m-MIBI in an experimental study using two animal models of diabetes, and is correlated with histological changes. The lack of difference in myocardial perfusion heterogeneity between control and diabetic animals suggests that animal models are poorly suited, or that the technology currently available does not seem satisfactory to obtain similar results as the clinical study. (author)

  9. Quantitative evaluation of benign meningioma and hemangiopericytoma with peritumoral brain edema by 64-slice CT perfusion imaging

    Institute of Scientific and Technical Information of China (English)

    REN Guang; CHEN Shuang; WANG Yin; ZHU Rui-jiang; GENG Dao-ying; FENG Xiao-yuan

    2010-01-01

    Background Hemangiopericytomas (HPCs) have a relentless tendency for local recurrence and metastases,differentiating between benign meningiomas and HPCs before surgery is important for both treatment planning and the prognosis appraisal.The purpose of this study was to evaluate the correlations between CT perfusion parameters and microvessel density (MVD) in extra-axial tumors and the possible role of CT perfusion imaging in preoperatively differentiating benign meningiomas and HPCs.Methods Seventeen patients with benign meningiomas and peritumoral edema, 12 patients with HPCs and peritumoral edema underwent 64-slice CT perfusion imaging pre-operation.Perfusion was calculated using the Patlak method.The quantitative parameters, include cerebral blood volume (CBV), permeability surface (PS) of parenchyma, peritumoral edema among benign meningiomas and HPCs were compared respectively.CBV and PS in parenchyma, peritumoral edema of benign meningiomas and HPCs were also compared to that of the contrallateral normal white matter respectively.The correlations between CBV, PS of tumoral parenchyma and MVD were examined.Results The value of CBV and PS in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05), while the values of CBV and PS in peritumoral edema of benign meningiomas and HPCs were not significantly different (P >0.05).MVD in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05).There were positive correlations between CBV and MVD (r=0.648, P<0.05), PS and MVD (r=0.541, P<0.05) respectively.Furthermore, the value of CBV and PS in parenchyma of benign meningiomas and HPCs were significantly higher than that of contrallateral normal white matter (P<0.05), the value of CBV in peritumoral edema of benign meningiomas and HPCs were significantly lower than that of contrallateral normal white matter (P<0.05), while the value of PS in peritumoral edema of benign meningiomas and HPCs were not

  10. A combined procedure for sup(99m)Tc aerosol ventilation and perfusion imaging

    International Nuclear Information System (INIS)

    For several years, radioaerosols have been successfully used to provide detailed images of regional ventilation to aid in the differential diagnosis of pulmonary embolism. It has been widely advocated that the ventilation images should follow the perfusion scan and that the amount of aerosol deposited in the patient's lungs should be three times greater than the perfusion dose. We employed an alternative approach which avoided the deposition of an unpredictable amount of aerosol in individual patients. The aerosol study was performed first, and the activity of the microspheres used for the perfusion images was then tailored to the actual amount of aerosol which the patient had retained. This allowed a microsphere/aerosol activity ratio of 10:1 to be readily achieved, thus successfully masking the ventilation pattern by the perfusion activity. The faster biological clearance of sup(99m)Tc-DTPA aerosol from the lung fields, as compared to sup(99m)Tc-sulphur-colloid aerosol, allowed higher initial activities to be deposited in the lungs, thus enabling a high-resolution collimator to be used. When the perfusion study was delayed by 1 h (one effective half-life for the sup(99m)Tc-DTPA aerosol), it was not necessary to increase the perfusion activity required to mask the ventilation image. (orig.)

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

    Science.gov (United States)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

  13. Assessment of SPECT ventilation-perfusion imaging in patients with lung cancer

    International Nuclear Information System (INIS)

    Ventilation and perfusion SPECT images during tidal breathing were studied in 15 cases of lung cancer using 81mKr gas and 99mTc-microspheres. Furthermore, functional images of V/Q ratio and Q/V ratio were prepared, and their clinical significance is discussed with reference to general lung function. There was a decrease in %VC and %FEVi.0 in 7 of 15 cases, and an increase of AaDo2 in the blood gas analysis in 12 of 15 cases. Both planar and SPECT images showed ventilation and perfusion abnormalities in all 15 cases. Of these, 12 patients showed matched ventilation and perfusion defects, 2 patients a dead-space effect and 1 patient a shunt effect. In comparing planar and SPECT images, depiction of ventilation and perfusion impairments were equally clear in 11 cases, but in 3, showing a lobar or segmental defect with a shunt effect, the SPECT images were superior. In a patient with markedly impaired function of the affected lung, the remaining function could not be depicted by SPECT. From the above, it seems that better information can be obtained for understanding the ventilation and perfusion states of lung cancer by adding the SPECT images to the planar image. (orig.)

  14. Non-ischemic perfusion defects due to delayed arrival of contrast material on stress perfusion cardiac magnetic resonance imaging after coronary artery bypass graft surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeo Koon; Park, Eun Ah; Park, Sang Joon; Cheon, Gi Jeong; Lee, Whal; Chung, Jin Wook; Park, Jae Hyung [Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-04-15

    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.

  15. Non-ischemic perfusion defects due to delayed arrival of contrast material on stress perfusion cardiac magnetic resonance imaging after coronary artery bypass graft surgery

    International Nuclear Information System (INIS)

    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.

  16. The Role of Rest Image in patients Showing Normal Stress Image on Tc-99m Myocardial Perfusion Scan

    International Nuclear Information System (INIS)

    Tc-99m myocardial perfusion agents such as Tc-99m sestamibi or Tc-99m tetrofosmin has advantages over T1-201 for myocardial perfusion scan such as low attenuation and easy availability. However, Tc-99m agents do not redistribute so they need to 13 be given 2 times, namely after stress and at rest. To evaluate whether rest image is needed in patients showing normal stress images, 43 patients who underwent both myocardial perfusion scan and coronary angiography and showed normal stress images were evaluated. Findings of rest images of them were evaluated whether they change the diagnosis or treatment plans. Among 43 patients who showed normal stress myocardial perfusion imaging, 31 (72.1%) showed no additional information. However, among 5 patients with vasospastic angina 4(80%) showed abnormal rest images in spite of normal stress images. So, when vasospastic angina is suspected clinically, rest image could be helpful identifying patients with coronary vasospasm. In conclusion, rest myocardial perfusion images were not helpful in 72.1 % of patients with angina when stress images were normal. In only exception was those with vasospastic angina.

  17. Perfusion and ventilation filters for Fourier-decomposition MR lung imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wujcicki, Artur; Materka, Andrzej [Lodz University of Technology (Poland). Inst. of Electronics; Corteville, Dominique; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine

    2015-05-01

    MR imaging without the use of contrast agents has recently been used for creating perfusion and ventilation functional lung images. The technique incorporates frequency- or wavelet-domain filters to separate the MR signal components. This paper presents a new, subject-adaptive algorithm for perfusion and ventilation filters design. The proposed algorithm uses a lung signal model for separation of the signal components in the frequency domain. Non-stationary lung signals are handled by a short time Fourier transform. This method was applied to sets of 192 and 90 co-registered non-contrast MR lung images measured for five healthy subjects at the rate of 3,33 images per second, using different slice thicknesses. In each case, the resulted perfusion and ventilation images showed a smaller amount of mutual information, when compared to those obtained using the known lowpass/highpass filter approach.

  18. Intravoxel incoherent motion perfusion imaging in acute stroke: initial clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Federau, C.; Becce, F.; Maeder, P.; Meuli, R. [Centre Hospitalier Universitaire Vaudois (CHUV) and University of Lausanne, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland); Sumer, S.; Wintermark, M. [University of Virginia, Neuroradiology Division, Department of Radiology, Charlottesville, VA (United States); O' Brien, K. [University of Geneva, Center for Biomedical Imaging (CIBM), Geneva (Switzerland)

    2014-08-15

    Intravoxel incoherent motion (IVIM) imaging is an MRI perfusion technique that uses a diffusion-weighted sequence with multiple b values and a bi-compartmental signal model to measure the so-called pseudo-diffusion of blood caused by its passage through the microvascular network. The goal of the current study was to assess the feasibility of IVIM perfusion fraction imaging in patients with acute stroke. Images were collected in 17 patients with acute stroke. Exclusion criteria were onset of symptoms to imaging >5 days, hemorrhagic transformation, infratentorial lesions, small lesions <0.5 cm in minimal diameter and hemodynamic instability. IVIM imaging was performed at 3 T, using a standard spin-echo Stejskal-Tanner pulsed gradients diffusion-weighted sequence, using 16 b values from 0 to 900 s/mm{sup 2}. Image quality was assessed by two radiologists, and quantitative analysis was performed in regions of interest placed in the stroke area, defined by thresholding the apparent diffusion coefficient maps, as well as in the contralateral region. IVIM perfusion fraction maps showed an area of decreased perfusion fraction f in the region of decreased apparent diffusion coefficient. Quantitative analysis showed a statistically significant decrease in both IVIM perfusion fraction f (0.026 ± 0.019 vs. 0.056 ± 0.025, p = 2.2 . 10{sup -6}) and diffusion coefficient D compared with the contralateral side (3.9 ± 0.79 . 10{sup -4} vs. 7.5 ± 0.86 . 10{sup -4} mm{sup 2}/s, p = 1.3 . 10{sup -20}). IVIM perfusion fraction imaging is feasible in acute stroke. IVIM perfusion fraction is significantly reduced in the visible infarct. Further studies should evaluate the potential for IVIM to predict clinical outcome and treatment response. (orig.)

  19. A case of cerebral infarction showing interesting SPECT images

    International Nuclear Information System (INIS)

    A case of cerebral infarction showing interesting SPECT images was reported. One month after stroke, 81mKr and 99mTc-HMPAO-SPECT were showed post ischemic high flow area as hot lesion, but 123I-IMP-SPECT was showed as cold lesion in early scan. Two months after stroke, all SPECT images showed infarction as cold area. (author)

  20. Direct myocardial perfusion imaging in valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Soto, R.C.; Durante, M.L.; Villacorta, E.V.; Torres, J.F.; Monzon, O.P.

    1981-02-01

    Twenty two patients with rheumatic valvular heart disease - 21 having a history of heart failure - were studied using direct coronary injection of /sup 99m/Tc labelled MAA particles during the course of hemodynamic and arteriographic studies. Myocardial perfusion deficit patterns have been shown to be consistent or indicative of either patchy, regional or gross ischemia. In patients with history of documented heart failure 90% (18 cases) had ischemic perfusion deficit in the involved ventricle. We conclude that diminished myocardial blood flow is an important mechanism contributing to the development of heart failure.

  1. Study on 64-layer Spiral Computed Tomography Perfusion Imaging in Patients with Fatty Liver

    Institute of Scientific and Technical Information of China (English)

    RAO Xiao-hui; SU Qi; CAI Lei; QIN Jia-sheng; CAI Li-quan; HONG He; WANG Kang-hua; AI Zhi-guo; ZHANG Sheng

    2014-01-01

    Objective:To analyze the changes of hemodynamics of patients with fatty liver by detecting their blood perfusion parameter changes with Philips Brilliance 64-layer spiral computed tomography (CT) perfusion technique. Methods: A total of 74 patients undergoing 64-layer spiral CT perfusion imaging were selected as study objects, in which 39 were with fatty liver and the other 35 were healthy people. The parameters of liver blood perfusion were observed. Results: Hepatic arterial perfusion (Art.Perf), portal perfusion (Port.Perf) and total perfusion (Total.Perf) values as well as hepatic perfusion index (HPI) were (18.4±4.1), (71.5±14.2) and (93.2±6.7) mL/100 g·min as well as (25.15±5.22)% in control group, in which the Art.Perf, Port.Perf and Total.Perf were in close association with the severity of fatty liver and of great significance. Art.Perf of patients with mild, moderate and severe fatty liver was (15.4±4.0), (7.3±9.6) and (4.1±1.3) mL/100 g·min, Port.Perf was (56.5±10.7), (48.6±6.8) and (37.0±4.1) mL/100 g·min and Total.Perf was (71.3±5.7), (55.7±5.8) and (40.2±5.0) mL/100 g·min, respectively. However, HPI could not be considered as the evaluation index for the severity of fatty liver. Conclusion:CT perfusion imaging of liver can relfect blood changes of patients with fatty liver, which can be used to evaluate their blood-supply condition, thus providing more diagnostic evidences for the clinic.

  2. High accuracy of arterial spin labeling perfusion imaging in differentiation of pilomyxoid from pilocytic astrocytoma

    International Nuclear Information System (INIS)

    Pilomyxoid astrocytoma (PMA) is a relatively new tumor entity which has been added to the 2007 WHO Classification of tumors of the central nervous system. The goal of this study is to utilize arterial spin labeling (ASL) perfusion imaging to differentiate PMA from pilocytic astrocytoma (PA). Pulsed ASL and conventional MRI sequences of patients with PMA and PA in the past 5 years were retrospectively evaluated. Patients with history of radiation or treatment with anti-angiogenic drugs were excluded. A total of 24 patients (9 PMA, 15 PA) were included. There were statistically significant differences between PMA and PA in mean tumor/gray matter (GM) cerebral blood flow (CBF) ratios (1.3 vs 0.4, p < 0.001) and maximum tumor/GM CBF ratio (2.3 vs 1, p < 0.001). Area under the receiver operating characteristic (ROC) curves for differentiation of PMA from PA was 0.91 using mean tumor CBF, 0.95 using mean tumor/GM CBF ratios, and 0.89 using maximum tumor/GM CBF. Using a threshold value of 0.91, the mean tumor/GM CBF ratio was able to diagnose PMA with 77 % sensitivity, 100 % specificity, and a threshold value of 0.7, provided 88 % sensitivity and 86 % specificity. There was no statistically significant difference between the two tumors in enhancement pattern (p = 0.33), internal architecture (p = 0.15), or apparent diffusion coefficient (ADC) values (p = 0.07). ASL imaging has high accuracy in differentiating PMA from PA. The result of this study may have important applications in prognostication and treatment planning especially in patients with less accessible tumors such as hypothalamic-chiasmatic gliomas. (orig.)

  3. High accuracy of arterial spin labeling perfusion imaging in differentiation of pilomyxoid from pilocytic astrocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, S.A.; Assadsangabi, R.; Hajmomenian, M.; Vossough, A. [Perelman School of Medicine of the University of Pennsylvania, Department of Radiology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Santi, M. [Perelman School of Medicine of the University of Pennsylvania, Department of Pathology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States)

    2015-05-01

    Pilomyxoid astrocytoma (PMA) is a relatively new tumor entity which has been added to the 2007 WHO Classification of tumors of the central nervous system. The goal of this study is to utilize arterial spin labeling (ASL) perfusion imaging to differentiate PMA from pilocytic astrocytoma (PA). Pulsed ASL and conventional MRI sequences of patients with PMA and PA in the past 5 years were retrospectively evaluated. Patients with history of radiation or treatment with anti-angiogenic drugs were excluded. A total of 24 patients (9 PMA, 15 PA) were included. There were statistically significant differences between PMA and PA in mean tumor/gray matter (GM) cerebral blood flow (CBF) ratios (1.3 vs 0.4, p < 0.001) and maximum tumor/GM CBF ratio (2.3 vs 1, p < 0.001). Area under the receiver operating characteristic (ROC) curves for differentiation of PMA from PA was 0.91 using mean tumor CBF, 0.95 using mean tumor/GM CBF ratios, and 0.89 using maximum tumor/GM CBF. Using a threshold value of 0.91, the mean tumor/GM CBF ratio was able to diagnose PMA with 77 % sensitivity, 100 % specificity, and a threshold value of 0.7, provided 88 % sensitivity and 86 % specificity. There was no statistically significant difference between the two tumors in enhancement pattern (p = 0.33), internal architecture (p = 0.15), or apparent diffusion coefficient (ADC) values (p = 0.07). ASL imaging has high accuracy in differentiating PMA from PA. The result of this study may have important applications in prognostication and treatment planning especially in patients with less accessible tumors such as hypothalamic-chiasmatic gliomas. (orig.)

  4. Kinetic assessment of manganese using magnetic resonance imaging in the dually perfused human placenta in vitro

    International Nuclear Information System (INIS)

    The transfer and distribution of paramagnetic manganese was investigated in the dually perfused human placenta in vitro (using 10, 20, 100 μM Mn with and without 54Mn) using magnetic resonance imaging (MRI) and conventional radiochemical techniques. The human placenta concentrated 54Mn rapidly during the first 15 min of perfusion and by 4 hr was four times greater than the concentrations of Mn in the maternal perfusate, while the concentration of Mn in the fetal perfusate was 25% of the maternal perfusate levels. Within placentae, 45% of the 54Mn was free in the 100,000g supernatant, with 45% in the 1000g pellet. The magnetic field dependence of proton nuclear spin-lattice relaxation time (T1) in placental tissue supports this Mn binding. Mn primarily affected the MRI partial saturation rather than spin-echo images of the human placenta, which provided for the separation of perfusate contributions from those produced by Mn. The washout of the Mn from the placenta was slow compared with its uptake, as determined by MRI. Thus, Mn was concentrated by the human placenta, but transfer of Mn across the placenta was limited in either direction. These studies also illustrate the opportunity for studies of human placental function using magnetic resonance imaging as a noninvasive biomarker

  5. Blood-brain barrier permeability imaging using perfusion computed tomography

    Directory of Open Access Journals (Sweden)

    Avsenik Jernej

    2015-06-01

    Full Text Available Background. The blood-brain barrier represents the selective diffusion barrier at the level of the cerebral microvascular endothelium. Other functions of blood-brain barrier include transport, signaling and osmoregulation. Endothelial cells interact with surrounding astrocytes, pericytes and neurons. These interactions are crucial to the development, structural integrity and function of the cerebral microvascular endothelium. Dysfunctional blood-brain barrier has been associated with pathologies such as acute stroke, tumors, inflammatory and neurodegenerative diseases.

  6. Intravoxel incoherent motion perfusion imaging in acute stroke: initial clinical experience

    International Nuclear Information System (INIS)

    Intravoxel incoherent motion (IVIM) imaging is an MRI perfusion technique that uses a diffusion-weighted sequence with multiple b values and a bi-compartmental signal model to measure the so-called pseudo-diffusion of blood caused by its passage through the microvascular network. The goal of the current study was to assess the feasibility of IVIM perfusion fraction imaging in patients with acute stroke. Images were collected in 17 patients with acute stroke. Exclusion criteria were onset of symptoms to imaging >5 days, hemorrhagic transformation, infratentorial lesions, small lesions 2. Image quality was assessed by two radiologists, and quantitative analysis was performed in regions of interest placed in the stroke area, defined by thresholding the apparent diffusion coefficient maps, as well as in the contralateral region. IVIM perfusion fraction maps showed an area of decreased perfusion fraction f in the region of decreased apparent diffusion coefficient. Quantitative analysis showed a statistically significant decrease in both IVIM perfusion fraction f (0.026 ± 0.019 vs. 0.056 ± 0.025, p = 2.2 . 10-6) and diffusion coefficient D compared with the contralateral side (3.9 ± 0.79 . 10-4 vs. 7.5 ± 0.86 . 10-4 mm2/s, p = 1.3 . 10-20). IVIM perfusion fraction imaging is feasible in acute stroke. IVIM perfusion fraction is significantly reduced in the visible infarct. Further studies should evaluate the potential for IVIM to predict clinical outcome and treatment response. (orig.)

  7. Contribution of perfusion-weighted magnetic resonance imaging in the differentiation of meningiomas and other extra-axial tumors: case reports and literature review.

    Science.gov (United States)

    Zimny, Anna; Sasiadek, Marek

    2011-07-01

    We present six cases of extra-axial lesions: three meningiomas [including one intraventricular and one cerebellopontine angle (CPA) meningioma], one dural metastasis, one CPA schwannoma and one choroid plexus papilloma which were chosen from a larger cohort of extra-axial tumors evaluated in our institution. Apart from conventional MR examinations, all the patients also underwent perfusion-weighted imaging (PWI) using dynamic susceptibility contrast method on a 1.5 T MR unit (contrast: 0.3 mmol/kg, rate 5 ml/s). Though the presented tumors showed very similar appearance on conventional MR images, they differed significantly in perfusion examinations. The article draws special attention to the usefulness of PWI in the differentiation of various extra-axial tumors and its contribution in reaching final correct diagnoses. Finding a dural lesion with low perfusion parameters strongly argues against the diagnosis of meningioma and should raise a suspicion of a dural metastasis. In cases of CPA tumors, a lesion with low relative cerebral blood volume values should be suspected to be schwannoma, allowing exclusion of meningioma to be made. In intraventricular tumors arising from choroid plexus, low perfusion parameters can exclude a diagnosis of meningioma. In our opinion, PWI as an easy and quick to perform functional technique should be incorporated into the MR protocol of all intracranial tumors including extra-axial neoplasms. PMID:21061142

  8. Intra-voxel incoherent motion perfusion MR Imaging: a wake-up call

    International Nuclear Information System (INIS)

    This work gives the results of several studies made by different authors on IVIM MR Imaging. It appears that there are genuine potential applications for IVIM MR imaging. Perfusion is a very important surrogate marker of many physiologic or pathologic processes. MR imaging perfusion parameters can be obtained by using gadolinium-based contrast agents, either injected as a bolus (to determine blood flow, transit times, etc) or in a steady-state mode (to address blood volume, vessel permeability, etc). With the rising concern of nephrogenic systemic fibrosis, some patients cannot be examined with such an approach. IVIM MR imaging may then appear as an interesting alternative to provide crucial clues on perfusion in tissues, such as the kidneys, the liver, or even the placenta during pregnancy. (O.M.)

  9. Effects of smoking on lung uptake of 201Tl during exercise myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Objective: To investigate the influence of smoking on lung uptake of 201Tl during myocardial perfusion imaging. Methods: Ninety-two healthy subjects, with normal 201Tl myocardial perfusion imaging findings but no evidence of left ventricular hypertrophy and pulmonary disease, were divided into three groups, smoker, nonsmoker and quitted smoker groups. Exercise/delay 201Tl myocardial perfusion imaging was performed on all subjects included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: Both the lung/heart ratios during exercise in smoker (0.40 ± 0.07, F=10.635, P201Tl lung/heart ratios in smokers are higher than in nonsmokers and this must be kept in mind when 201Tl lung/heart ratios are used clinically, even in quitted smokers

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  11. Myocardial CT perfusion imaging and SPECT for the diagnosis of coronary artery disease

    DEFF Research Database (Denmark)

    George, Richard T; Mehra, Vishal C; Chen, Marcus Y;

    2014-01-01

    . MATERIALS AND METHODS: This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise or...... pharmacologic stress SPECT before and within 60 days of coronary angiography. Images from CT perfusion imaging, SPECT, and coronary angiography were interpreted at blinded, independent core laboratories. The primary diagnostic parameter was the area under the receiver operating characteristic curve (Az...

  12. The value of brain blood perfusion SPECT imaging in evaluation of the curative effect of hyperbaric oxygen in patients with ischemic brain injury

    International Nuclear Information System (INIS)

    Objective: Brain blood flow SPECT perfusion can detect changes in brain blood flow. The obiective of this study was to explore the clinical value of SPECT perfusion imaging in brain ischemic injury due to traumatic at before and after hyperbaric oxygen (HBO)treatment.Methods: Sixty-five cases of secondary ischemic brain injury patients were randomly divided into two groups. One was with HBO treatment group and the other was with conventional treatment. All had brain perfusion SPECT at before and after treatment. Computer region of interest (ROI)technology was applied in the cross-sectional images using lo-cat mirror ratio (Ra) method to determine cerebral ischemic lesions. The t-test was used to analyze the quantitative data. It would be considered as abnormal if the brain perfusion SPECT reduce Ra ≤ 0.9 aftertreatment. Results: In HBO treatment group.regional cerebral blood flow (rCBF) before and after treatment to reduce the district Ra values were 0.58 ± 0.1l and 0.82 ± 0.12 (t=7.327, P<0.01). In con-ventional treatment group. Rcbf before and after treatment to reduce the district Ra values were 0.6l ± 0.13 and 0.73 ± 0.12 (t=2.153. P=0.038). IncreaSed Rcbf at ischemic lesions in HBO treatment group was 0.24 ± 0.08 and was 0.12 ± 0.06 for conventional treatment group (t=2.571. P=0.015). Conclusions: Brain SPECT imaging could sensitively reflect the rCBF before and after treatment and was considered to be useful for therapeutic monitoring of HBO treatment efficacy. (authors)

  13. Relative indexes of cutaneous blood perfusion measured by real-time laser Doppler imaging (LDI) in healthy volunteers.

    Science.gov (United States)

    Seyed Jafari, S Morteza; Schawkat, Megir; Van De Ville, Dimitri; Shafighi, Maziar

    2014-07-01

    We used real-time LDI to study regional variations in microcirculatory perfusion in healthy candidates to establish a new methodology for global perfusion body mapping that is based on intra-individual perfusion index ratios. Our study included 74 (37 female) healthy volunteers aged between 22 and 30 years (mean 24.49). Imaging was performed using a recent microcirculation-imaging camera (EasyLDI) for different body regions of each volunteer. The perfusion values were reported in Arbitrary Perfusion Units (APU). The relative perfusion indexes for each candidate's body region were then obtained by normalization with the perfusion value of the forehead. Basic parameters such as weight, height, and blood pressure were also measured and analyzed. The highest mean perfusion value was reported in the forehead area (259.21APU). Mean perfusion in the measured parts of the body correlated positively with mean forehead value, while there was no significant correlation between forehead blood perfusion values and room temperature, BMI, systolic blood pressure and diastolic blood pressure (p=0.420, 0.623, 0.488, 0.099, respectively). Analysis of the data showed that perfusion indexes were not significantly different between male and female volunteers except for the ventral upper arm area (p=.001). LDI is a non-invasive, fast technique that opens several avenues for clinical applications. The mean perfusion indexes are useful in clinical practice for monitoring patients before and after surgical interventions. Perfusion values can be predicted for different body parts for patients only by taking the forehead perfusion value and using the perfusion index ratios to obtain expected normative perfusion values. PMID:24788075

  14. Functional MRI using Fourier decomposition of lung signal: Reproducibility of ventilation- and perfusion-weighted imaging in healthy volunteers

    International Nuclear Information System (INIS)

    Purpose: To assess the reproducibility of Fourier decomposition (FD) based ventilation- and perfusion-weighted lung MRI. Methods: Sixteen healthy volunteers were examined on a 1.5 T whole-body MR-scanner with 4–6 sets of coronal slices over the chest volume with a non-contrast enhanced steady-state free precession sequence. The identical protocol was repeated after 24 h. Reconstructed perfusion- and ventilation-weighted images were obtained through non-rigid registration and FD post-processing of images. Analysis of signal in segmented regions of interest was performed for both native and post-processed data. Two blinded chest radiologists rated image quality of perfusion- and ventilation-weighted images using a 3-point scale. Results: Reproducibility of signal between the two time points was very good with intra-class correlation coefficients of 0.98, 0.94 and 0.86 for native, perfusion- and ventilation-weighted images, respectively. Perfusion- and ventilation-weighted images were of overall good quality with proportions of diagnostic images of 87–95% and 69–75%, respectively. Lung signal decreased from posterior to anterior slices with image quality of ventilation-weighted images in anterior areas rated worse than in posterior or perfusion-weighted images. Inter- and intra-observer agreement of image quality was good for perfusion and ventilation. Conclusions: The study demonstrates high reproducibility of ventilation- and perfusion-weighted FD lung MRI

  15. Functional MRI using Fourier decomposition of lung signal: Reproducibility of ventilation- and perfusion-weighted imaging in healthy volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Lederlin, Mathieu, E-mail: mathieu.lederlin@chu-bordeaux.fr [Department of Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Department of Thoracic and Cardiovascular Imaging, University Hospital of Bordeaux, Av de Magellan, 33600 Pessac (France); Bauman, Grzegorz, E-mail: g.bauman@dkfz.de [Division of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Eichinger, Monika, E-mail: m.eichinger@dkfz.de [Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Dinkel, Julien, E-mail: julien.dinkel@googlemail.com [Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114 (United States); Brault, Mathilde, E-mail: mathilde.brault@isped.u-bordeaux2.fr [Methodological Unit of Support for Research (USMR), University Bordeaux Segalen, 146 rue Léo Saignat, 33076 Bordeaux (France); Biederer, Jürgen, E-mail: juergen.biederer@uni-heidelberg.de [Department of Radiology, University Hospital Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Puderbach, Michael, E-mail: m.puderbach@dkfz.de [Division of Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Chest Clinics at the University of Heidelberg, Clinics for Interventional and Diagnostic Radiology, Amalienstr. 5, 69126 Heidelberg (Germany)

    2013-06-15

    Purpose: To assess the reproducibility of Fourier decomposition (FD) based ventilation- and perfusion-weighted lung MRI. Methods: Sixteen healthy volunteers were examined on a 1.5 T whole-body MR-scanner with 4–6 sets of coronal slices over the chest volume with a non-contrast enhanced steady-state free precession sequence. The identical protocol was repeated after 24 h. Reconstructed perfusion- and ventilation-weighted images were obtained through non-rigid registration and FD post-processing of images. Analysis of signal in segmented regions of interest was performed for both native and post-processed data. Two blinded chest radiologists rated image quality of perfusion- and ventilation-weighted images using a 3-point scale. Results: Reproducibility of signal between the two time points was very good with intra-class correlation coefficients of 0.98, 0.94 and 0.86 for native, perfusion- and ventilation-weighted images, respectively. Perfusion- and ventilation-weighted images were of overall good quality with proportions of diagnostic images of 87–95% and 69–75%, respectively. Lung signal decreased from posterior to anterior slices with image quality of ventilation-weighted images in anterior areas rated worse than in posterior or perfusion-weighted images. Inter- and intra-observer agreement of image quality was good for perfusion and ventilation. Conclusions: The study demonstrates high reproducibility of ventilation- and perfusion-weighted FD lung MRI.

  16. Prognostic value of normal myocardial perfusion images using technetium-99m based compounds

    International Nuclear Information System (INIS)

    Full text: The prognostic value of 201Tl myocardial perfusion imaging is well established. The purpose of this study was to describe the clinical outcome of patients with known or suspected ischemic heart disease and a normal myocardial perfusion scan using 99mTc labelled agents (Sestamibi/Tetrofosmin). Fifty-three patients (29 males, 24 females, mean age 51.58 years) with known or suspected coronary artery disease (CAD) were stressed (3 with dipyridamole and 50 with bicycle ergometer) and gated SPECT myocardial perfusion scan obtained with triple head gamma camera. All patients had normal myocardial perfusion and wall motion. Patients were followed up for 21-24 months and follow up data was obtained from telephone interview. Cardiac events were defined as, hard events (myocardial infarct, unstable angina, death) or soft events (angioplasty or other revascularization). ST segment depression occurred in 11 (20.75%), 6 (11.32%) had pre-test angiographically significant CAD, 4 (7.55%) were studied post CABG and 3 (5.6%) patients had a normal post scan angiography. Cardiac events occurred in none of the patients. Our study confirms the benign outcome of patients with normal myocardial perfusion scan using 99mTc labelled agents, even in patients with angiographically significant CAD, consistent with prior observation for 201Tl cardiac imaging. The lesser number of patients who underwent coronary angiography following a normal perfusion scan shows the determination by treating physicians, that no further evaluation was necessary

  17. Implementation of quantitative perfusion imaging using pulsed arterial spin labeling at ultra-high field.

    Science.gov (United States)

    Gardener, A G; Gowland, P A; Francis, S T

    2009-04-01

    This study compares the implementation of the STAR and FAIR pulsed arterial spin labeling (PASL) schemes to form quantitative perfusion maps at ultra-high field, 7 Tesla (T), and high field, 3 T. Phantom experiments were performed to compare the inversion efficiency and profile of the labeling pulses at 7 T and 3 T and to optimize in-plane saturation techniques. The perfusion weighted (PW) signal was measured at a range of postlabeling delay times and quantitative perfusion maps were calculated on a voxel-by-voxel basis. An increase in PW signal was found with field strength, and together with the increased signal-to-noise ratio, this led to improved image signal-to-noise and quality of fit of perfusion maps at 7 T. PMID:19189295

  18. Scatter and attenuation correction changes interpretation of gated myocardial perfusion imaging

    DEFF Research Database (Denmark)

    Johansen, Allan; Grupe, Peter; Veje, Annegrete;

    2004-01-01

    Attenuation correction may improve the diagnostic accuracy of myocardial perfusion imaging (MPI). However, few studies have dealt with the clinical consequences for reporting. We compared routine reports based on scatter-corrected MPI (MPI-routine) with consensus readings of scatter-corrected (MPI......-scatter) and scatter plus attenuation-corrected studies (MPI-attenuation) to investigate the impact of attenuation correction on reporting. One hundred consecutive stable angina patients (including 55 men) were investigated in a 99mTc-sestamibi 2-day gated protocol with scatter and attenuation correction. With...... MPI-routine, 53 patients had normal perfusion and 47 abnormal perfusion, compared to 62 and 38 with MPI-attenuation, and 54 and 46, respectively, with MPI-scatter. Agreement between MPI-routine and MPI-attenuation with respect to overall diagnosis (normal/abnormal perfusion) was 89% (kappa=0...

  19. Myocardial first-pass perfusion imaging with hybrid-EPI: frequency-offsets and potential artefacts

    Directory of Open Access Journals (Sweden)

    Ferreira Pedro F

    2012-06-01

    Full Text Available Abstract Background First-pass myocardial perfusion is often imaged with a tailored hybrid centric interleaved echo-planar-imaging sequence, providing rapid image acquisition with good contrast enhancement. The centric interleaved phase-encode order minimises the effective time-of-echo but it is sensitive to frequency-offsets. This short article aims to show possible artefacts that might originate with this sequence, in the context of first-pass perfusion imaging, when frequency-offsets are present. Non-uniform magnitude modulation effects were also analysed. Methods Numerical and phantom simulations were used to illustrate the effects of frequency-offsets and non-uniform magnitude modulation with this sequence in a typical perfusion protocol. In vivo data was post-processed to analyse the h-EPI’s sensitivity to the frequency-offsets. Results The centric phase-order was shown to be highly sensitive to frequency-offsets due to its symmetrical phase slope. Resulting artefacts include blurring, and splitting of the image into two identical copies along the phase-encode direction. It was also shown that frequency-offsets can introduce signal loss and ghosting of the right ventricle signal into the myocardium. The in vivo results were confirmed by numerical and phantom simulations. Magnitude modulation effects were found to be small. Conclusions Imaging first-pass myocardial perfusion with an hybrid centric echo-planar-imaging sequence can be corrupted with ghosting and splitting of the image due to frequency-offsets.

  20. Non-invasive imaging in detecting myocardial viability: Myocardial function versus perfusion

    Directory of Open Access Journals (Sweden)

    Iqbal A. Elfigih

    2014-12-01

    Full Text Available Coronary artery disease (CAD is the most prevalent and single most common cause of morbidity and mortality [1] with the resulting left ventricular (LV dysfunction an important complication. The distinction between viable and non-viable myocardium in patients with LV dysfunction is a clinically important issue among possible candidates for myocardial revascularization. Several available non-invasive techniques are used to detect and assess ischemia and myocardial viability. These techniques include echocardiography, radionuclide images, cardiac magnetic resonance imaging and recently myocardial computed tomography perfusion imaging. This review aims to distinguish between the available non-invasive imaging techniques in detecting signs of functional and perfusion viability and identify those which have the most clinical relevance in detecting myocardial viability in patients with CAD and chronic ischemic LV dysfunction. The most current available studies showed that both myocardial perfusion and function based on non-invasive imaging have high sensitivity with however wide range of specificity for detecting myocardial viability. Both perfusion and function imaging modalities provide complementary information about myocardial viability and no optimum single imaging technique exists that can provide very accurate diagnostic and prognostic viability assessment. The weight of the body of evidence suggested that non-invasive imaging can help in guiding therapeutic decision making in patients with LV dysfunction.

  1. Cerebral Fat Embolism: Diffusion-weighted Magnetic Resonance Imaging Findings

    International Nuclear Information System (INIS)

    PURPOSE: To demonstrate the diffusion-weighted (DWI) magnetic resonance imaging (MRI) findings, and the follow-up MRI findings, of cerebral fat embolism in the acute stage. MATERIAL AND METHODS: The initial DWI and clinical findings of six patients with cerebral fat embolism were retrospectively evaluated. The finding of DWI with a b-value of 1000 s/mm2 (b=1000) was compared with that of DWI with a b-value of 0 s/mm2 (b=0). In three patients who underwent follow-up MRI, the interval change of the lesion on T2-weighted images was investigated. RESULTS: The characteristic DWI finding of cerebral fat embolism in the acute stage was multiple, hyperintense, dot-like lesions disseminated in the brain. These lesions were distributed dominantly in the bilateral border-zone areas. Some lesions had an ancillary location including the cortex, deep white matter, basal ganglia, and cerebellum. The lesions were more intense and numerous in DWI (b=1000) than in DWI (b=0). The findings on the follow-up T2-weighted images were multiple confluent hyperintense lesions in the white matter with progression since the initial MRI. CONCLUSION: DWI could be a sensitive tool for detecting cerebral fat embolism in the acute phase. It is recommended that DWI be included in the initial evaluation of cerebral fat embolism with MRI

  2. 3-Fluoro-Deoxyglucose for the assessment of cerebral perfusion and glucose transport - Indications for extracranial-intracranial arterial bypass and followup studies

    International Nuclear Information System (INIS)

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

  3. The imaging of myocardial perfusion with sup(81m)Kr during coronary arteriography

    International Nuclear Information System (INIS)

    The use of 81sup(m)Kr was investigated for imaging myocardial perfusion during coronary arteriography using conventional catheters. When the significance of stenosis judged by arteriography is unclear, the effect on tissue perfusion can be established and the contribution to collateral flow by each artery separately evaluated. The distribution of sup(81m)Kr, due to its 13-s half-life, represents regional blood flow. In order to evaluate interventions, studies can be repeated at a low radiation risk to patients. A sterile pyrogen-free 81Rb-81Kr generator was developed. With slow infusion, inadequate mixing and streaming takes place due to laminar flow in coronary arteries. Fast intermittent 3-ml 81K-dextrose bolus injections convincingly eliminated streaming artefacts. Imaging was performed in 13 patients with a mobile scintillation camera and digital imaging system. Blood flow was calculated using the inert gas washout technique. There was good correlation (r = 0.91) between coronary blood flow determinations using sup(81m)Kr and 133Xe respectively. The perfusion images correlated well with the coronary angiograms. Total coronary arterial occlusions as demonstrated by arteriography were all shown as perfusion defects during rest. During atrial pacing myocardial flow was increased two-fold in normal coronary arteries and to a lesser extent in arteries with significant disease. The most critical lesion in a branch of a left coronary artery leads to a redistribution of perfusion during pacing. (orig.)

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

    International Nuclear Information System (INIS)

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

  5. The impact of exercise myocardial perfusion SPECT imaging on the selection of patients for coronary angiography

    International Nuclear Information System (INIS)

    Objective: Exercise 99Tcm-MIBI myocardial perfusion SPECT is accurate for the diagnosis of coronary artery disease (CAD). This study assessed the impact of exercise myocardial perfusion imaging on the selection of patients for coronary angiography. Methods: 2188 consecutive patients who underwent exercise myocardial perfusion SPECT in authors' department in 1999 were retrospectively analyzed. Among them, 1807 were men, 381 women (average age: 53.5 +- 7.2 years). Overall, exercise myocardial SPECT was normal in 1731 patients, abnormal in 359 cases, and equivocal in 98 patients. There were 141 patients who underwent CAG within 60 days after myocardial SPECT. Results: Overall, 12% of the patients with abnormal SPECT imaging underwent coronary angiography, but only 5% of the patients with a normal SPECT imaging did (P < 0.001). Among these 141 patients who underwent coronary angiography, significant coronary stenosis was present in 91% of the patients who had had an abnormal SPECT imaging, but only 8% of those who had had a normal SPECT imaging (P < 0.001). In those patients who underwent coronary angiography, revascularization rate was 25% for the patients with abnormal SPECT