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Sample records for asl perfusion mri

  1. Neural Substrates Associated with Weather-Induced Mood Variability: An Exploratory Study Using ASL Perfusion fMRI

    OpenAIRE

    Gillihan, Seth J.; Detre, John A.; Farah, Martha J.; Rao, Hengyi

    2011-01-01

    Daily variations in weather are known to be associated with variations in mood. However, little is known about the specific brain regions that instantiate weather-related mood changes. We used a data-driven approach and ASL perfusion fMRI to assess the neural substrates associated with weather-induced mood variability. The data-driven approach was conducted with mood ratings under various weather conditions (N = 464). Forward stepwise regression was conducted to develop a statistical model of...

  2. Arterial spin labeling-fast imaging with steady-state free precession (ASL-FISP): a rapid and quantitative perfusion technique for high-field MRI.

    Science.gov (United States)

    Gao, Ying; Goodnough, Candida L; Erokwu, Bernadette O; Farr, George W; Darrah, Rebecca; Lu, Lan; Dell, Katherine M; Yu, Xin; Flask, Chris A

    2014-08-01

    Arterial spin labeling (ASL) is a valuable non-contrast perfusion MRI technique with numerous clinical applications. Many previous ASL MRI studies have utilized either echo-planar imaging (EPI) or true fast imaging with steady-state free precession (true FISP) readouts, which are prone to off-resonance artifacts on high-field MRI scanners. We have developed a rapid ASL-FISP MRI acquisition for high-field preclinical MRI scanners providing perfusion-weighted images with little or no artifacts in less than 2 s. In this initial implementation, a flow-sensitive alternating inversion recovery (FAIR) ASL preparation was combined with a rapid, centrically encoded FISP readout. Validation studies on healthy C57/BL6 mice provided consistent estimation of in vivo mouse brain perfusion at 7 and 9.4 T (249 ± 38 and 241 ± 17 mL/min/100 g, respectively). The utility of this method was further demonstrated in the detection of significant perfusion deficits in a C57/BL6 mouse model of ischemic stroke. Reasonable kidney perfusion estimates were also obtained for a healthy C57/BL6 mouse exhibiting differential perfusion in the renal cortex and medulla. Overall, the ASL-FISP technique provides a rapid and quantitative in vivo assessment of tissue perfusion for high-field MRI scanners with minimal image artifacts.

  3. Comparison of arterial spin labeling and dynamic susceptibility contrast perfusion MRI in patients with acute stroke.

    Directory of Open Access Journals (Sweden)

    Yen-Chu Huang

    Full Text Available BACKGROUND: The aim of this study was to evaluate whether arterial spin labeling (ASL perfusion magnetic resonance imaging (MRI can reliably quantify perfusion deficit as compared to dynamic susceptibility contrast (DSC perfusion MRI. METHODS: Thirty-nine patients with acute ischemic stroke in the anterior circulation territory were recruited. All underwent ASL and DSC MRI perfusion scans within 30 hours after stroke onset and 31 patients underwent follow-up MRI scans. ASL cerebral blood flow (CBF and DSC time to maximum (T(max maps were used to calculate the perfusion defects. The ASL CBF lesion volume was compared to the DSC Tmax lesion volume by Pearson's correlation coefficient and likewise the ASL CBF and DSC T(max lesion volumes were compared to the final infarct sizes respectively. A repeated measures analysis of variance and least significant difference post hoc test was used to compare the mean lesion volumes among ASL CBF, DSC T(max >4-6 s and final infarct. RESULTS: Mean patient age was 72.6 years. The average time from stroke onset to MRI was 13.9 hours. The ASL lesion volume showed significant correlation with the DSC lesion volume for T(max >4, 5 and 6 s (r = 0.81, 0.82 and 0.80; p5 s (29.2 ml, p6 s (21.8 ml, p5 or 6 s were close to mean final infarct size. CONCLUSION: Quantitative measurement of ASL perfusion is well correlated with DSC perfusion. However, ASL perfusion may overestimate the perfusion defects and therefore further refinement of the true penumbra threshold and improved ASL technique are necessary before applying ASL in therapeutic trials.

  4. Arterial spin-labelling perfusion MRI and outcome in neonates with hypoxic-ischemic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Vis, Jill B. de; Hendrikse, Jeroen [University Medical Center Utrecht, Department of Radiology, HP E 01.132, P.O. Box 85500, Utrecht (Netherlands); Petersen, Esben T. [University Medical Center Utrecht, Department of Radiology, HP E 01.132, P.O. Box 85500, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiotherapy, Utrecht (Netherlands); Vries, Linda S. de; Bel, Frank van; Alderliesten, Thomas; Negro, Simona; Groenendaal, Floris; Benders, Manon J.N.L. [Wilhelmina Children' s Hospital/University Medical Center Utrecht, Department of Neonatology, Utrecht (Netherlands)

    2015-01-15

    Hyperperfusion may be related to outcome in neonates with hypoxic-ischemic encephalopathy (HIE). The purpose of this study was to evaluate whether arterial spin labelling (ASL) perfusion is associated with outcome in neonates with HIE and to compare the predictive value of ASL MRI to known MRI predictive markers. Twenty-eight neonates diagnosed with HIE and assessed with MR imaging (conventional MRI, diffusion-weighted MRI, MR spectroscopy [MRS], and ASL MRI) were included. Perfusion in the basal ganglia and thalami was measured. Outcome at 9 or 18 months of age was scored as either adverse (death or cerebral palsy) or favourable. The median (range) perfusion in the basal ganglia and thalami (BGT) was 63 (28-108) ml/100 g/min in the neonates with adverse outcome and 28 (12-51) ml/100 g/min in the infants with favourable outcome (p < 0.01). The area-under-the-curve was 0.92 for ASL MRI, 0.97 for MRI score, 0.96 for Lac/NAA and 0.92 for ADC in the BGT. The combination of Lac/NAA and ASL MRI results was the best predictor of outcome (r {sup 2} = 0.86, p < 0.001). Higher ASL perfusion values in neonates with HIE are associated with a worse neurodevelopmental outcome. A combination of the MRS and ASL MRI information is the best predictor of outcome. (orig.)

  5. Noninvasive method for mapping CVR in moyamoya disease using ASL-MRI

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    Noguchi, Tomoyuki, E-mail: tnogucci@radiol.med.kyushu-u.ac.jp [Department of Radiology, National center for Global Health and Medicine, 1-21-1, Toyama, Shinjuku-ku, Tokyo 162-8655 (Japan); Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Kawashima, Masatou, E-mail: m996kawa@cc.saga-u.ac.jp [Department of Neurosugery, Faculty of Medicine and Graduate School of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Nishihara, Masashi, E-mail: nishiham@cc.saga-u.ac.jp [Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Egashira, Yoshiaki, E-mail: bunta1974@yahoo.co.jp [Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Azama, Shinya, E-mail: azama-ssam-71257@b2.bunbun.ne.jp [Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Irie, Hiroyuki, E-mail: irie@cc.saga-u.ac.jp [Department of Radiology, Faculty of Medicine and Graduate School of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan)

    2015-06-15

    Highlights: • A clinical use of a pulse-wave-synchronized ASL-MRI (pulsy ASL-MRI) was proposed. • Resting IMP-SPECT correlated with pulsy ASL-MRI in moyamoya disease. • ASL-MRI could measure cerebrovascular reserve noninvasively in moyamoya disease. - Abstract: Purpose: To project a noninvasive method for mapping cerebrovascular reserve (CVR) in moyamoya disease (MMD) using ASL-MRI. Methods: 16 MMD patients underwent cerebral blood flow (CBF) examinations by standard ASL-MRI, pulse-wave-synchronized ASL-MRI (pulsy ASL-MRI) which tagged the arterial blood coincident with a peak of a pulse wave, and single photon emission computed tomography (SPECT) imagings with iodine-123-N-isopropyl-p-iodoamphetamine in the resting (rest-IMP) and after acetazolamide challenge (ACZ-IMP). Hemispheric 32-sided cerebral blood flow (CBF) values were measured with normalized CBF maps created from standard ASL-MRI (standard-ASL value), pulsy ASL-MRI (pulsy-ASL value), rest-IMP (rest-IMP value), and ACZ-IMP (ACZ-IMP value). CVR based on rest-IMP and ACZ-IMP values (IMP-CVR) was calculated. ASL-CVR was also calculated on the basis of corrected standard-ASL values and pulsy-ASL values, which were adjusted to the ACZ-IMP values and rest-IMP values, respectively, by the least-squares method. We assessed the relationships between rest-IMP values and pulsy-ASL values, ACZ-IMP values and standard-ASL values, and IMP-CVR and ASL-CVR. Results: Significant relationships were observed between rest-IMP values and pulsy-ASL values (correlation coefficient (r = 0.557, p < 0.01)), ACZ-IMP values and standard-ASL values (r = 0.825, p < 0.01), and IMP-CVR and ASL-CVR (r = 0.736, p < 0.01). Conclusions: ASL-MRI is equivalent to SPECT and that it might serve as a noninvasive method for mapping CVR in MMD.

  6. Arterial spin labeling perfusion MRI: Inter-vendor reproducibility and clinical applicability

    NARCIS (Netherlands)

    H.J.M.M. Mutsaerts

    2015-01-01

    Arterial spin labeling (ASL) is a perfusion magnetic resonance imaging (MRI) technique that non-invasively measures cerebral blood flow (CBF). The first part of this thesis concerns the inter-vendor reproducibility of ASL. Studies in this thesis show that on a total gray matter (GM) level, long-term

  7. Technological advances in MRI measurement of brain perfusion.

    Science.gov (United States)

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

    2005-12-01

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

  8. 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.)

  9. Arterial spin-labelling perfusion MRI and outcome in neonates with hypoxic-ischemic encephalopathy

    International Nuclear Information System (INIS)

    Hyperperfusion may be related to outcome in neonates with hypoxic-ischemic encephalopathy (HIE). The purpose of this study was to evaluate whether arterial spin labelling (ASL) perfusion is associated with outcome in neonates with HIE and to compare the predictive value of ASL MRI to known MRI predictive markers. Twenty-eight neonates diagnosed with HIE and assessed with MR imaging (conventional MRI, diffusion-weighted MRI, MR spectroscopy [MRS], and ASL MRI) were included. Perfusion in the basal ganglia and thalami was measured. Outcome at 9 or 18 months of age was scored as either adverse (death or cerebral palsy) or favourable. The median (range) perfusion in the basal ganglia and thalami (BGT) was 63 (28-108) ml/100 g/min in the neonates with adverse outcome and 28 (12-51) ml/100 g/min in the infants with favourable outcome (p 2 = 0.86, p < 0.001). Higher ASL perfusion values in neonates with HIE are associated with a worse neurodevelopmental outcome. A combination of the MRS and ASL MRI information is the best predictor of outcome. (orig.)

  10. 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.)

  11. Automatic assessment of cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Stegmann, Mikkel Bille; Larsson, Henrik B.W.

    2004-01-01

    In this paper, a method based on Active Appearance Models (AAM) is applied for automatic registration of myocardial perfusion MRI. A semi-quantitative perfusion assessment of the registered image sequences is presented. This includes the formation of perfusion maps for three parameters; maximum up...

  12. Regional and voxel-wise comparisons of blood flow measurements between dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and arterial spin labeling (ASL) in brain tumors.

    Science.gov (United States)

    White, Carissa M; Pope, Whitney B; Zaw, Taryar; Qiao, Joe; Naeini, Kourosh M; Lai, Albert; Nghiemphu, Phioanh L; Wang, J J; Cloughesy, Timothy F; Ellingson, Benjamin M

    2014-01-01

    The objective of the current study was to evaluate the regional and voxel-wise correlation between dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) measurement of cerebral blood flow (CBF) in patients with brain tumors. Thirty patients with histologically verified brain tumors were evaluated in the current study. DSC-MRI was performed by first using a preload dose of gadolinium contrast, then collecting a dynamic image acquisition during a bolus of contrast, followed by posthoc contrast agent leakage correction. Pseudocontinuous ASL was collected using 30 pairs of tag and control acquisition using a 3-dimensional gradient-echo spin-echo (GRASE) acquisition. All images were registered to a high-resolution anatomical atlas. Average CBF measurements within regions of contrast-enhancement and T2 hyperintensity were evaluated between the two modalities. Additionally, voxel-wise correlation between CBF measurements obtained with DSC and ASL were assessed. Results demonstrated a positive linear correlation between DSC and ASL measurements of CBF when regional average values were compared; however, a statistically significant voxel-wise correlation was only observed in around 30-40% of patients. These results suggest DSC and ASL may provide regionally similar, but spatially different measurements of CBF.

  13. Physiological and psychological individual differences influence resting brain function measured by ASL perfusion.

    Science.gov (United States)

    Kano, M; Coen, S J; Farmer, A D; Aziz, Q; Williams, S C R; Alsop, D C; Fukudo, S; O'Gorman, R L

    2014-09-01

    Effects of physiological and/or psychological inter-individual differences on the resting brain state have not been fully established. The present study investigated the effects of individual differences in basal autonomic tone and positive and negative personality dimensions on resting brain activity. Whole-brain resting cerebral perfusion images were acquired from 32 healthy subjects (16 males) using arterial spin labeling perfusion MRI. Neuroticism and extraversion were assessed with the Eysenck Personality Questionnaire-Revised. Resting autonomic activity was assessed using a validated measure of baseline cardiac vagal tone (CVT) in each individual. Potential associations between the perfusion data and individual CVT (27 subjects) and personality score (28 subjects) were tested at the level of voxel clusters by fitting a multiple regression model at each intracerebral voxel. Greater baseline perfusion in the dorsal anterior cingulate cortex (ACC) and cerebellum was associated with lower CVT. At a corrected significance threshold of p personality traits (amygdala, caudate, etc.) during active task processing. The resting brain state may therefore need to be taken into account when interpreting the neurobiology of individual differences in structural and functional brain activity.

  14. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill;

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...

  15. Fast Registration of Cardiac Perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsson, Henrik B. W.

    2003-01-01

    This abstract presents a novel method for registration of cardiac perfusion MRI sequences. By performing complex analyses of variance and clustering in an annotated training set off-line, our method provides real-time segmentation in an on-line setting. This renders the method feasible for live...

  16. Dynamic contrast enhanced MRI for perfusion quantification

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke

    2002-01-01

    Magnetic resonance imaging, during bolus passage of a paramagnetic contrast agent, is used world-wide to obtain parameters that reflect the pathological state of tissue. Abnormal perfusion occurs in diseases such as stoke and tumour. Consequently, perfusion quantication could have signi cant...... clinical value both in diagnosis and treatment of such pathologies. One approach for perfusion quanti cation involves using the contrast mechanism that a ects the transverse relaxation rates of the magnetization, R2 or R 2 , since this provides the most pronounced effect. However, the linearity between...... the contrastagent concentration, [Ca], and the changes in R2 or R 2 has been questioned. In this thesis, an MRI scanner sequence for detection of the longitudinal relaxation rate, R1 during bolus passage was modied for brain perfusion measurements, since the linearity between the changes in R1 and [Ca] is expected...

  17. Chronic and treatment-resistant depression: a study using arterial spin labeling perfusion MRI at 3Tesla.

    OpenAIRE

    Duhameau, Bérengère; Ferré, Jean-Christophe; Jannin, Pierre; Gauvrit, Jean-Yves; Vérin, Marc; Millet, Bruno; Drapier, Dominique

    2010-01-01

    International audience The aim of the present study was to compare patients displaying chronic and treatment-resistant depression with healthy controls, using the resting-state perfusion with arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) technique at 3T. The study focused on the subgenual anterior cingulate cortex (sACC), which is a key component in the pathophysiology of depression. Six patients with chronic and treatment-resistant depression and six healthy cont...

  18. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill;

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...... of Gd-DTPA (lambda), the vascular blood volume (Vb), and the time delay through the coronary arteries (delta T). The model was evaluated by computer simulation and used on experimental results from seven healthy subjects. The results in the healthy volunteers for a region of interest placed...... in the anterior myocardial wall were (mean +/- SD) Ki = 54 +/- 10 ml/100 g/min, lambda = 30 +/- 3 ml/100 g, Vb = 9 +/- 2 ml/100 g, delta T = 3.2 +/- 1.1 s. These results are in good agreement with similar results obtained by other methods....

  19. 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.)

  20. Non-invasive and quantitative evaluation of peripheral vascular resistances in rats by combined NMR measurements of perfusion and blood pressure using ASL and dynamic angiography.

    Science.gov (United States)

    Ménard, Jacques C; Giacomini, Eric; Baligand, Céline; Fromes, Yves; Carlier, Pierre G

    2010-02-01

    The in vivo determination of peripheral vascular resistances (VR) is crucial for the assessment of arteriolar function. It requires simultaneous determination of organ perfusion (F) and arterial blood pressure (BP). A fully non-invasive method was developed to measure systolic and diastolic BP in the caudal artery of rats based on dynamic NMR angiography. A good agreement was found between the NMR approach and the gold standard techniques (linear regression slope = 0.98, R(2) = 0.96). This method and the ASL-MRI measurement of skeletal muscle perfusion were combined into one single NMR experiment to quantitatively evaluate the local vascular resistances in the calf muscle of anaesthetized rats, in vivo and non-invasively 1) at rest: VR = 7.0 +/- 1.0 mmHg x min 100 g x ml(-1), F = 13 +/- 3 ml min(-1) x 100 g(-1) and mean BP (MBP) = 88 +/- 10 mmHg; 2) under vasodilator challenge (milrinone): VR = 3.7 +/- 1.1 mmHg min x 100 g ml(-1), F = 21 +/- 4 ml min(-1) x 100 g(-1) and MBP = 75 +/- 14 mmHg; 3) under vasopressor challenge (norepinephrine): VR = 9.8 +/- 1.2 mmHg min 100 g ml(-1), F = 14 +/- 3 ml min(-1) x 100 g(-1) and MBP = 137 +/- 2 mmHg. PMID:19795372

  1. Perfusion MRI in neuro-psychiatric systemic lupus erthemathosus.

    NARCIS (Netherlands)

    Emmer, B.J.; Osch, M.J. van; Wu, O.; Steup-Beekman, G.M.; Steens, S.; Huizinga, T.W.J.; Buchem, M.A. van; Grond, J. van der

    2010-01-01

    PURPOSE: To use perfusion weighted MR to quantify any perfusion abnormalities and to determine their contribution to neuropsychiatric (NP) involvement in systemic lupus erythematosus (SLE). MATERIALS AND METHODS: We applied dynamic susceptibility contrast (DSC) perfusion MRI in 15 active NPSLE, 26 i

  2. [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.

  3. Inter-study reproducibility of arterial spin labelling magnetic resonance imaging for measurement of renal perfusion in healthy volunteers at 3 Tesla

    OpenAIRE

    Gillis, Keith A.; McComb, Christie; Foster, John E.; Taylor, Alison; Patel, Rajan K.; Morris, Scott; Alan G. Jardine; Schneider, Markus P; Roditi, Giles H; Delles, Christian; Mark, Patrick B.

    2014-01-01

    Background: Measurement of renal perfusion is a crucial part of measuring kidney function. Arterial spin labelling magnetic resonance imaging (ASL MRI) is a non-invasive method of measuring renal perfusion using magnetised blood as endogenous contrast. We studied the reproducibility of ASL MRI in normal volunteers. Methods: ASL MRI was performed in healthy volunteers on 2 occasions using a 3.0 Tesla MRI scanner with flow-sensitive alternating inversion recovery (FAIR) perfusion prep...

  4. Improved visualization of delayed perfusion in lung MRI

    Energy Technology Data Exchange (ETDEWEB)

    Risse, Frank [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Eichinger, Monika [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Semmler, Wolfhard [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Puderbach, Michael, E-mail: m.puderbach@dkfz.de [Department of Radiology, German Cancer Research Center, Heidelberg (Germany)

    2011-01-15

    Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S{sub n,max} normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement {tau} to visualize regions with delayed bolus onset; and (3) ratio R = S{sub n,max}/{tau} was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

  5. Hepatocellular carcinoma: perfusion quantification with dynamic contrast-enhanced MRI

    NARCIS (Netherlands)

    Taouli, B.; Johnson, R.S.; Hajdu, C.H.; Oei, M.T.H.; Merad, M.; Yee, H.; Rusinek, H.

    2013-01-01

    The objective of our study was to report our initial experience with dynamic contrast-enhanced MRI (DCE-MRI) for perfusion quantification of hepatocellular carcinoma (HCC) and surrounding liver.DCE-MRI of the liver was prospectively performed on 31 patients with HCC (male-female ratio, 26:5; mean ag

  6. Non-contrast MRI perfusion angiosome in diabetic feet

    International Nuclear Information System (INIS)

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  7. Non-contrast MRI perfusion angiosome in diabetic feet

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jie [Cardiovascular Imaging Lab, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Hastings, Mary K.; Mueller, Michael J. [Washington University School of Medicine, The Program in Physical Therapy, St. Louis, MO (United States); Muccigross, David; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Fan, Zhaoyang [Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA (United States); Gao, Fabao [West China Hospital, Sichuan University, Department of Radiology, Chengdu (China); Curci, John [Washington University School of Medicine, The Department of Surgery, St. Louis, MO (United States)

    2015-01-15

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  8. Diagnostic value of perfusion MRI in classifying stroke

    International Nuclear Information System (INIS)

    Our study was designed to determine whether supplementary information obtained with perfusion MRI can enhance accuracy. We used delayed perfusion, as represented by time to peak map on perfusion MRI, to classify strokes in 39 patients. Strokes were classified as hemodynamic if delayed perfusion extended to a whole territory of the occluded arterial trunk; as embolic if delayed perfusion was absent or restricted to infarcts; as arteriosclerotic if infarcts were small, multiple, and located mainly in the basal ganglias; or as unclassified if the pathophysiology was unclear. We compared these findings with vascular lesions on cerebral angiography, neurological signs, infarction on MRI, ischemia on xenon-enhanced CT (Xe/CT) and collateral pathway development. Delayed perfusion clearly indicated the area of arterial occlusion. Strokes were classified as hemodynamic in 13 patients, embolic in 14 patients, arteriosclerotic in 6 patients and unclassified in 6 patients. Hemodynamic infarcts were seen only in deep white-matter areas such as the centrum semiovale or corona radiata, whereas embolic infarcts were in the cortex, cortex and subjacent white matter, and lenticulo-striatum. Embolic and arteriosclerotic infarcts occurred even in hemo-dynamically compromized hemispheres. Our findings indicate that perfusion MRI, in association with adetailed analysis of T2-weighted MRI of cerebral infarcts in the axial and coronal planes, can accurately classify stroke as hemodynamic, embolic or arteriosclerotic. (author)

  9. 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.

  10. Applications of arterial spin labeled MRI in the brain.

    Science.gov (United States)

    Detre, John A; Rao, Hengyi; Wang, Danny J J; Chen, Yu Fen; Wang, Ze

    2012-05-01

    Perfusion provides oxygen and nutrients to tissues and is closely tied to tissue function while disorders of perfusion are major sources of medical morbidity and mortality. It has been almost two decades since the use of arterial spin labeling (ASL) for noninvasive perfusion imaging was first reported. While initial ASL magnetic resonance imaging (MRI) studies focused primarily on technological development and validation, a number of robust ASL implementations have emerged, and ASL MRI is now also available commercially on several platforms. As a result, basic science and clinical applications of ASL MRI have begun to proliferate. Although ASL MRI can be carried out in any organ, most studies to date have focused on the brain. This review covers selected research and clinical applications of ASL MRI in the brain to illustrate its potential in both neuroscience research and clinical care.

  11. Automatic Characterization of Myocardial Perfusion in Contrast Enhanced MRI

    Science.gov (United States)

    Positano, Vincenzo; Santarelli, Maria Filomena; Landini, Luigi

    2003-12-01

    The use of contrast medium in cardiac MRI allows joining the high-resolution anatomical information provided by standard magnetic resonance with functional information obtained by means of the perfusion of contrast agent in myocardial tissues. The current approach to perfusion MRI characterization is the qualitative one, based on visual inspection of images. Moving to quantitative analysis requires extraction of numerical indices of myocardium perfusion by analysis of time/intensity curves related to the area of interest. The main problem in quantitative image sequence analysis is the heart movement, mainly due to patient respiration. We propose an automatic procedure based on image registration, segmentation of the myocardium, and extraction and analysis of time/intensity curves. The procedure requires a minimal user interaction, is robust with respect to the user input, and allows effective characterization of myocardial perfusion. The algorithm was tested on cardiac MR images acquired from voluntaries and in clinical routine.

  12. Diffusion and perfusion MRI of the lung and mediastinum

    Energy Technology Data Exchange (ETDEWEB)

    Henzler, Thomas, E-mail: Thomas.Henzler@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University (Germany); Schmid-Bindert, Gerald [Interdisciplinary Thoracic Oncology, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University (Germany); Schoenberg, Stefan O.; Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim - Heidelberg University (Germany)

    2010-12-15

    With ongoing technical improvements such as multichannel MRI, systems with powerful gradients as well as the development of innovative pulse sequence techniques implementing parallel imaging, MRI has now entered the stage of a radiation-free alternative to computed tomography (CT) for chest imaging in clinical practice. Whereas in the past MRI of the lung was focused on morphological aspects, current MRI techniques also enable functional imaging of the lung allowing for a comprehensive assessment of lung disease in a single MRI exam. Perfusion imaging can be used for the visualization of regional pulmonary perfusion in patients with different lung diseases such as lung cancer, chronic obstructive lung disease, pulmonary embolism or for the prediction of postoperative lung function in lung cancer patients. Over the past years diffusion-weighted MR imaging (DW-MRI) of the thorax has become feasible with a significant reduction of the acquisition time, thus minimizing artifacts from respiratory and cardiac motion. In chest imaging, DW-MRI has been mainly suggested for the characterization of lung cancer, lymph nodes and pulmonary metastases. In this review article recent MR perfusion and diffusion techniques of the lung and mediastinum as well as their clinical applications are reviewed.

  13. Diffusion and perfusion MRI of the lung and mediastinum.

    Science.gov (United States)

    Henzler, Thomas; Schmid-Bindert, Gerald; Schoenberg, Stefan O; Fink, Christian

    2010-12-01

    With ongoing technical improvements such as multichannel MRI, systems with powerful gradients as well as the development of innovative pulse sequence techniques implementing parallel imaging, MRI has now entered the stage of a radiation-free alternative to computed tomography (CT) for chest imaging in clinical practice. Whereas in the past MRI of the lung was focused on morphological aspects, current MRI techniques also enable functional imaging of the lung allowing for a comprehensive assessment of lung disease in a single MRI exam. Perfusion imaging can be used for the visualization of regional pulmonary perfusion in patients with different lung diseases such as lung cancer, chronic obstructive lung disease, pulmonary embolism or for the prediction of postoperative lung function in lung cancer patients. Over the past years diffusion-weighted MR imaging (DW-MRI) of the thorax has become feasible with a significant reduction of the acquisition time, thus minimizing artifacts from respiratory and cardiac motion. In chest imaging, DW-MRI has been mainly suggested for the characterization of lung cancer, lymph nodes and pulmonary metastases. In this review article recent MR perfusion and diffusion techniques of the lung and mediastinum as well as their clinical applications are reviewed. PMID:20627435

  14. Diffusion and perfusion MRI of the lung and mediastinum

    International Nuclear Information System (INIS)

    With ongoing technical improvements such as multichannel MRI, systems with powerful gradients as well as the development of innovative pulse sequence techniques implementing parallel imaging, MRI has now entered the stage of a radiation-free alternative to computed tomography (CT) for chest imaging in clinical practice. Whereas in the past MRI of the lung was focused on morphological aspects, current MRI techniques also enable functional imaging of the lung allowing for a comprehensive assessment of lung disease in a single MRI exam. Perfusion imaging can be used for the visualization of regional pulmonary perfusion in patients with different lung diseases such as lung cancer, chronic obstructive lung disease, pulmonary embolism or for the prediction of postoperative lung function in lung cancer patients. Over the past years diffusion-weighted MR imaging (DW-MRI) of the thorax has become feasible with a significant reduction of the acquisition time, thus minimizing artifacts from respiratory and cardiac motion. In chest imaging, DW-MRI has been mainly suggested for the characterization of lung cancer, lymph nodes and pulmonary metastases. In this review article recent MR perfusion and diffusion techniques of the lung and mediastinum as well as their clinical applications are reviewed.

  15. Nonrigid registration of myocardial perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur

    2005-01-01

    This paper describes a fully automatic registration of 10 multi-slice myocardial perfusion magnetic resonance image sequences. The registration of these sequences is crucial for the clinical interpretation, which currently is subjected to manual labour. The approach used in this study is a nonrigid...... registration algorithm based on free-form deformations due to Rueckert et al. Inspection of difference images from the wash-out part of the perfusion sequences indicates that a good registration accuracy is obtained....

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

    Science.gov (United States)

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

    2015-03-01

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

  17. Measuring myocardial perfusion: the role of PET, MRI and CT.

    Science.gov (United States)

    Qayyum, A A; Kastrup, J

    2015-06-01

    Recently, focus has changed from anatomical assessment of coronary arteries towards functional testing to evaluate the effect of stenosis on the myocardium before intervention. Besides positron-emission tomography (PET), cardiac MRI (CMR), and cardiac CT are able to measure myocardial perfusion. Myocardial perfusion abnormalities are the first sign of the ischaemic cascade in the development of coronary artery disease (CAD). PET is considered the non-invasive clinical reference standard for absolute quantification of myocardial perfusion. The diagnostic and prognostic value of PET is well-known and is used in routine clinical practice. However, PET uses radioactive tracers and has a lower spatial resolution compared to CMR and CT. CMR and CT are emerging techniques in the field of myocardial perfusion imaging. CMR uses magnetic resonance to obtain images, whereas CT uses x-rays during first-pass of non-ionic and ionic contrast agents, respectively. Absolute quantification with CMR has yet to be established in routine clinical practice, while CT has yet to prove its diagnostic and prognostic value. The upcoming years may change the way we diagnose and treat patients suspected of having CAD with more precise methods for measuring myocardial perfusion. The aim of this comprehensive review is to discuss current and emerging imaging techniques used for myocardial perfusion imaging.

  18. Glial fibrillary acidic protein (GFAP) immunoreactivity correlates with cortical perfusion parameters determined by bolus tracking arterial spin labelling (bt-ASL) magnetic resonance (MR) imaging in the Wistar Kyoto rat.

    Science.gov (United States)

    Gormley, Shane; Rouine, Jennifer; McIntosh, Allison; Kerskens, Christian; Harkin, Andrew

    2016-06-01

    Alterations in astrocyte number and function have been implicated in the pathophysiology of a number of psychiatric disorders. The development of magnetic resonance imaging (MRI) as a tool in the animal laboratory has enabled an investigation of the relationship between pathological and neuroimaging markers in animal models. However the physiological processes which underlie these markers and their role in mediating behavioural deficits is still poorly understood. Rodent models have provided us with important insights into physiological and cellular mechanisms which may mediate anxiety and depression-related behaviours. The Wistar-Kyoto (WKY) rat is a strain which endogenously expresses highly anxious and depressive-like behaviours and has previously been reported to exhibit alterations in immunoreactivity for the astrocytic marker glial fibrillary acidic protein (GFAP) in brain sub-regions relative to more stress resilient out-bred strains. Here we report that the depressive and anxiety-like behaviours exhibited by the WKY rat strain are associated with alterations in brain morphology including a decrease in hippocampal volume, coupled with reduced resting state frontal cortical perfusion as assessed by MR bolus tracking arterial spin labelling (bt-ASL) relative to the out-bred Wistar strain. Pre-limbic cortical GFAP immunoreactivity and astrocyte cell number were positively correlated with cortical blood perfusion in the WKY strain. These experiments provide a link between pathological and neuroimaging markers of aberrant astrocytic function and add validity to the WKY rat as a model for co-morbid anxiety and depression. PMID:27068181

  19. Quantification of MRI measured myocardial perfusion reserve in healthy humans: a comparison with positron emission tomography

    DEFF Research Database (Denmark)

    Fritz-Hansen, Thomas; Hove, Jens D; Kofoed, Klaus F;

    2008-01-01

    PURPOSE: To validate a noninvasive quantitative MRI technique, the K(i) perfusion method, for myocardial perfusion in humans using (13)N-ammonia PET as a reference method. MATERIALS AND METHODS: Ten healthy males (64 +/- 8 years) were examined with combined PET and MRI perfusion imaging at rest a...

  20. 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.

  1. 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

    technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose: To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC......, and 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......-MRI using two different regions for normalization and two different measurement approaches. Material and Methods: Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and r...

  2. Quantification of MRI measured myocardial perfusion reserve in healthy humans: A comparison with positron emission tomography

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Hove, J.D.; Kofoed, K.F.;

    2008-01-01

    and during stress induced by dipyridamole in order to determine the myocardial perfusion reserve. Myocardial and blood time concentration curves obtained by Gd-DTPA-enhanced MRI and N-13-ammonia PET were fitted by a two-compartment perfusion model. Results: Mean perfusion values (+/- SD) derived from the MRI......Purpose: To validate a noninvasive quantitative MRI technique, the K-i perfusion method, for myocardial perfusion in humans using N-13-ammonia PET as a reference method. Materials and Methods: Ten healthy males (64 +/- 8 years) were examined with combined PET and MRI perfusion imaging at rest...... method at rest and at hyperemia were 80 +/- 20 and 183 +/- 56 mL/min/100 g, respectively. The same data for PET were 71 +/- 16 and 203 +/- 67 mL/min/100 g. A linear relationship was observed between MRI and PET-derived myocardial perfusion reserve for regional and global data. Linear regression...

  3. 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.)

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

    Science.gov (United States)

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

    2012-05-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacik, Jan; Fiehler, Jens [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Neuroradiology; Reitz, Matthias; Schmidt, Nils O. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Neurosurgery; Bolar, Divya S. [Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA (United States). Radiology; Adalsteinsson, Elfar [Massachusetts Institute of Technology, Cambridge, MA (United States). Electrical Engineering and Computer Science

    2015-05-01

    The non-invasive assessment of (patho-)physiological parameters such as, perfusion and oxygenation, is of great importance for the characterization of pathologies e.g., tumors, which may be helpful to better predict treatment response and potential outcome. To better understand the influence of physiological parameters on the investigated oxygenation and perfusion sensitive MRI methods, MRI measurements were correlated with subsequent invasive micro probe measurements during free breathing conditions of air, air+10% CO2 and 100% O2 in healthy mice brain. MRI parameters were the irreversible (R2), reversible (R2') and effective (R2*) transverse relaxation rates, venous blood oxygenation level assessed by quantitative blood oxygenation level dependent (qBOLD) method and cerebral blood flow (CBF) assessed by arterial spin labeling (ASL) using a 7T small animal MRI scanner. One to two days after MRI, tissue perfusion and pO2 were measured by Laser-Doppler flowmetry and fluorescence quenching micro probes, respectively. The tissue pO2 values were converted to blood oxygen saturation by using the Hill equation. The animals were anesthetized by intra peritoneal injection of ketamine-xylazine-acepromazine (10-2-0.3 mg/ml.kg). Results for normal/hypercapnia/hyperoxia conditions were: R2[s {sup and} -1] = 20.7/20.4/20.1, R2*[s {sup and} -1] = 31.6/29.6/25.9, R2'[s {sup and} 1] = 10.9/9.2/5.7, qBOLD venous blood oxygenation level = 0.43/0.51/0.56, CBF[ml.min {sup and} -1.100g {sup and} -1] = 70.6/105.5/81.8, Laser-Doppler flowmetry[a.u.] = 89.2/120.2/90.6 and pO2[mmHg] = 6.3/32.3/46.7. All parameters were statistically significantly different with P < 0.001 between all breathing conditions. All MRI and the corresponding micro probe measurements were also statistically significantly (P ≤ 0.03) correlated with each other. However, converting the tissue pO2 to blood oxygen saturation = 0.02/0.34/0.63, showed only very limited agreement with the qBOLD venous blood

  6. Quantification of renal allograft perfusion using arterial spin labeling MRI: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Lanzman, Rotem S.; Wittsack, Hans-Joerg; Bilk, Philip; Kroepil, Patric; Blondin, Dirk [University Hospital Duesseldorf, Department of Radiology, Duesseldorf (Germany); Martirosian, Petros; Schick, Fritz [University Hospital Tuebingen, Section for Experimental Radiology, Department of Diagnostic Radiology, Tuebingen (Germany); Zgoura, Panagiota; Voiculescu, Adina [University Hospital Duesseldorf, Department of Nephrology, Duesseldorf (Germany)

    2010-06-15

    To quantify renal allograft perfusion in recipients with stable allograft function and acute decrease in allograft function using nonenhanced flow-sensitive alternating inversion recovery (FAIR)-TrueFISP arterial spin labeling (ASL) MR imaging. Following approval of the local ethics committee, 20 renal allograft recipients were included in this study. ASL perfusion measurement and an anatomical T2-weighted single-shot fast spin-echo (HASTE) sequence were performed on a 1.5-T scanner (Magnetom Avanto, Siemens, Erlangen, Germany). T2-weighted MR urography was performed in patients with suspected ureteral obstruction. Patients were assigned to three groups: group a, 6 patients with stable allograft function over the previous 4 months; group b, 7 patients with good allograft function who underwent transplantation during the previous 3 weeks; group c, 7 allograft recipients with an acute deterioration of renal function. Mean cortical perfusion values were 304.8 {+-} 34.4, 296.5 {+-} 44.1, and 181.9 {+-} 53.4 mg/100 ml/min for groups a, b and c, respectively. Reduction in cortical perfusion in group c was statistically significant. Our results indicate that ASL is a promising technique for nonenhanced quantification of cortical perfusion of renal allografts. Further studies are required to determine the clinical value of ASL for monitoring renal allograft recipients. (orig.)

  7. MO-G-18C-05: Real-Time Prediction in Free-Breathing Perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Song, H [Department of Radiology, University of Pittsburgh, Pittsburgh, PA (United States); Liu, W [Department of Bioengineering, UCLA, Los Angeles, CA (United States); Ruan, D [Department of Bioengineering, UCLA, Los Angeles, CA (United States); Department of Radiation Oncology, UCLA, Los Angeles, CA (United States); Jung, S [Department of Statistics, University of Pittsburgh, Pittsburgh, PA (United States); Gach, M [Department of Radiology, University of Pittsburgh, Pittsburgh, PA (United States); Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA (United States)

    2014-06-15

    Purpose: The aim is to minimize frame-wise difference errors caused by respiratory motion and eliminate the need for breath-holds in magnetic resonance imaging (MRI) sequences with long acquisitions and repeat times (TRs). The technique is being applied to perfusion MRI using arterial spin labeling (ASL). Methods: Respiratory motion prediction (RMP) using navigator echoes was implemented in ASL. A least-square method was used to extract the respiratory motion information from the 1D navigator. A generalized artificial neutral network (ANN) with three layers was developed to simultaneously predict 10 time points forward in time and correct for respiratory motion during MRI acquisition. During the training phase, the parameters of the ANN were optimized to minimize the aggregated prediction error based on acquired navigator data. During realtime prediction, the trained ANN was applied to the most recent estimated displacement trajectory to determine in real-time the amount of spatial Results: The respiratory motion information extracted from the least-square method can accurately represent the navigator profiles, with a normalized chi-square value of 0.037±0.015 across the training phase. During the 60-second training phase, the ANN successfully learned the respiratory motion pattern from the navigator training data. During real-time prediction, the ANN received displacement estimates and predicted the motion in the continuum of a 1.0 s prediction window. The ANN prediction was able to provide corrections for different respiratory states (i.e., inhalation/exhalation) during real-time scanning with a mean absolute error of < 1.8 mm. Conclusion: A new technique enabling free-breathing acquisition during MRI is being developed. A generalized ANN development has demonstrated its efficacy in predicting a continuum of motion profile for volumetric imaging based on navigator inputs. Future work will enhance the robustness of ANN and verify its effectiveness with human

  8. MO-G-18C-05: Real-Time Prediction in Free-Breathing Perfusion MRI

    International Nuclear Information System (INIS)

    Purpose: The aim is to minimize frame-wise difference errors caused by respiratory motion and eliminate the need for breath-holds in magnetic resonance imaging (MRI) sequences with long acquisitions and repeat times (TRs). The technique is being applied to perfusion MRI using arterial spin labeling (ASL). Methods: Respiratory motion prediction (RMP) using navigator echoes was implemented in ASL. A least-square method was used to extract the respiratory motion information from the 1D navigator. A generalized artificial neutral network (ANN) with three layers was developed to simultaneously predict 10 time points forward in time and correct for respiratory motion during MRI acquisition. During the training phase, the parameters of the ANN were optimized to minimize the aggregated prediction error based on acquired navigator data. During realtime prediction, the trained ANN was applied to the most recent estimated displacement trajectory to determine in real-time the amount of spatial Results: The respiratory motion information extracted from the least-square method can accurately represent the navigator profiles, with a normalized chi-square value of 0.037±0.015 across the training phase. During the 60-second training phase, the ANN successfully learned the respiratory motion pattern from the navigator training data. During real-time prediction, the ANN received displacement estimates and predicted the motion in the continuum of a 1.0 s prediction window. The ANN prediction was able to provide corrections for different respiratory states (i.e., inhalation/exhalation) during real-time scanning with a mean absolute error of < 1.8 mm. Conclusion: A new technique enabling free-breathing acquisition during MRI is being developed. A generalized ANN development has demonstrated its efficacy in predicting a continuum of motion profile for volumetric imaging based on navigator inputs. Future work will enhance the robustness of ANN and verify its effectiveness with human

  9. Arterial and portal venous liver perfusion using selective spin labelling MRI

    Energy Technology Data Exchange (ETDEWEB)

    Schalkx, Hanke J.; Petersen, Esben T.; Veldhuis, Wouter B.; Leeuwen, Maarten S. van; Bosch, Maurice A.A.J. van den [University Medical Center Utrecht, Department of Radiology, HP E.01.132, Postbus 85500, Utrecht (Netherlands); Peters, Nicky H.G.M. [Atrium Medical Center Parkstad, Department of Radiology, Heerlen (Netherlands); Pluim, Josien P.W.; Stralen, Marijn van [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands)

    2015-06-01

    To investigate the feasibility of selective arterial and portal venous liver perfusion imaging with spin labelling (SL) MRI, allowing separate labelling of each blood supply. The portal venous perfusion was assessed with a pulsed EPISTAR technique and the arterial perfusion with a pseudo-continuous sequence. To explore precision and reproducibility, portal venous and arterial perfusion were separately quantified in 12 healthy volunteers pre- and postprandially (before and after meal intake). In a subgroup of 6 volunteers, the accuracy of the absolute portal perfusion and its relative postprandial change were compared with MRI flow measurements of the portal vein. The portal venous perfusion significantly increased from 63 ± 22 ml/100g/min preprandially to 132 ± 42 ml/100g/min postprandially. The arterial perfusion was lower with 35 ± 22 preprandially and 22 ± 30 ml/100g/min postprandially. The pre- and postprandial portal perfusion using SL correlated well with flow-based perfusion (r{sup 2} = 0.71). Moreover, postprandial perfusion change correlated well between SL- and flow-based quantification (r{sup 2} = 0.77). The SL results are in range with literature values. Selective spin labelling MRI of the portal venous and arterial blood supply successfully quantified liver perfusion. This non-invasive technique provides specific arterial and portal venous perfusion imaging and could benefit clinical settings where contrast agents are contraindicated. (orig.)

  10. MRI methods for pulmonary ventilation and perfusion imaging; Methoden der MRT zur Ventilations- und Perfusionsbildgebung der Lunge

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, G. [Universitaetsspital Basel, Klinik fuer Radiologie und Nuklearmedizin, Basel (Switzerland); Bauman, G. [Universitaetsspital Basel, Klinik fuer Radiologie und Nuklearmedizin - Radiologische Physik, Basel (Switzerland)

    2016-02-15

    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, O{sub 2}-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.) [German] Die separate Beurteilung von Atemmechanik, Gasaustauschprozessen und Lungenzirkulation ist wesentlich fuer die Diagnose und Therapie von Lungenerkrankungen. Klinische Lungenfunktionstests sind aufgrund ihrer zumeist nur globalen Aussage oft nicht hinreichend spezifisch in der Differenzialdiagnostik oder eingeschraenkt sensitiv bei der

  11. Tracer kinetic modelling in MRI: estimating perfusion and capillary permeability

    International Nuclear Information System (INIS)

    The tracer-kinetic models developed in the early 1990s for dynamic contrast-enhanced MRI (DCE-MRI) have since become a standard in numerous applications. At the same time, the development of MRI hardware has led to increases in image quality and temporal resolution that reveal the limitations of the early models. This in turn has stimulated an interest in the development and application of a second generation of modelling approaches. They are designed to overcome these limitations and produce additional and more accurate information on tissue status. In particular, models of the second generation enable separate estimates of perfusion and capillary permeability rather than a single parameter Ktrans that represents a combination of the two. A variety of such models has been proposed in the literature, and development in the field has been constrained by a lack of transparency regarding terminology, notations and physiological assumptions. In this review, we provide an overview of these models in a manner that is both physically intuitive and mathematically rigourous. All are derived from common first principles, using concepts and notations from general tracer-kinetic theory. Explicit links to their historical origins are included to allow for a transfer of experience obtained in other fields (PET, SPECT, CT). A classification is presented that reveals the links between all models, and with the models of the first generation. Detailed formulae for all solutions are provided to facilitate implementation. Our aim is to encourage the application of these tools to DCE-MRI by offering researchers a clearer understanding of their assumptions and requirements. (topical review)

  12. Tracer kinetic modelling in MRI: estimating perfusion and capillary permeability

    Science.gov (United States)

    Sourbron, S. P.; Buckley, D. L.

    2012-01-01

    The tracer-kinetic models developed in the early 1990s for dynamic contrast-enhanced MRI (DCE-MRI) have since become a standard in numerous applications. At the same time, the development of MRI hardware has led to increases in image quality and temporal resolution that reveal the limitations of the early models. This in turn has stimulated an interest in the development and application of a second generation of modelling approaches. They are designed to overcome these limitations and produce additional and more accurate information on tissue status. In particular, models of the second generation enable separate estimates of perfusion and capillary permeability rather than a single parameter Ktrans that represents a combination of the two. A variety of such models has been proposed in the literature, and development in the field has been constrained by a lack of transparency regarding terminology, notations and physiological assumptions. In this review, we provide an overview of these models in a manner that is both physically intuitive and mathematically rigourous. All are derived from common first principles, using concepts and notations from general tracer-kinetic theory. Explicit links to their historical origins are included to allow for a transfer of experience obtained in other fields (PET, SPECT, CT). A classification is presented that reveals the links between all models, and with the models of the first generation. Detailed formulae for all solutions are provided to facilitate implementation. Our aim is to encourage the application of these tools to DCE-MRI by offering researchers a clearer understanding of their assumptions and requirements.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-15

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

  14. Choice of the regularization parameter for perfusion quantification with MRI

    Science.gov (United States)

    Sourbron, S.; Luypaert, R.; Van Schuerbeek, P.; Dujardin, M.; Stadnik, T.

    2004-07-01

    Truncated singular value decomposition (TSVD) is an effective method for the deconvolution of dynamic contrast enhanced (DCE) MRI. Two robust methods for the selection of the truncation threshold on a pixel-by-pixel basis—generalized cross validation (GCV) and the L-curve criterion (LCC)—were optimized and compared to paradigms in the literature. GCV and LCC were found to perform optimally when applied with a smooth version of TSVD, known as standard form Tikhonov regularization (SFTR). The methods lead to improvements in the estimate of the residue function and of its maximum, and converge properly with SNR. The oscillations typically observed in the solution vanish entirely, and perfusion is more accurately estimated at small mean transit times. This results in improved image contrast and increased sensitivity to perfusion abnormalities, at the cost of 1-2 min in calculation time and hyperintense clusters in the image. Preliminary experience with clinical data suggests that the latter problem can be resolved using spatial continuity and/or hybrid thresholding methods. In the simulations GCV and LCC are equivalent in terms of performance, but GCV thresholding is faster.

  15. Assessment of pulmonary parenchyma perfusion with FAIR in comparison with DCE-MRI-Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Fan Li [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China)], E-mail: fanli0930@163.com; Liu Shiyuan [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China); Sun Fei [GE Healthcare China (China)], E-mail: Fei.sun@med.ge.com; Xiao Xiangsheng [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China)], E-mail: lizhaobin79@163.com

    2009-04-15

    Objective: The aim of this study was to assess pulmonary parenchyma perfusion with flow-sensitive alternating inversion recovery (FAIR) in comparison with 3D dynamic contrast-enhanced (DCE) imaging in healthy volunteers and in patients with pulmonary embolism or lung cancer. Materials and methods: Sixteen healthy volunteers and 16 patients with pulmonary embolism (5 cases) or lung cancer (11 cases) were included in this study. Firstly, the optimized inversion time of FAIR (TI) was determined in 12 healthy volunteers. Then, FAIR imaging with the optimized TI was performed followed by DCE-MRI on the other 4 healthy volunteers and 16 patients. Tagging efficiency of lung and SNR of perfusion images were calculated with different TI values. In the comparison of FAIR with DCE-MRI, the homogeneity of FAIR and DCE-MRI perfusion was assessed. In the cases of perfusion abnormality, the contrast between normal lung and perfusion defects was quantified by calculating a normalized signal intensity ratio. Results: One thousand milliseconds was the optimal TI, which generated the highest lung tagging efficiency and second highest PBF SNR. In the volunteers, the signal intensity of perfusion images acquired with both FAIR and DCE-MRI was homogeneous. Wedged-shaped or triangle perfusion defects were visualized in five pulmonary embolisms and three lung cancer cases. There was no significant statistical difference in signal intensity ratio between FAIR and DCE-MRI (P > 0.05). In the rest of eight lung cancers, all the lesions showed low perfusion against the higher perfused pulmonary parenchyma in both FAIR and DCE-MRI. Conclusion: Pulmonary parenchyma perfusion imaging with FAIR was feasible, consistent and could obtain similar functional information to that from DCE-MRI.

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

    Science.gov (United States)

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

    2013-10-01

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

  17. Differences in perfusion parameters between upper and lower lumbar vertebral segments with dynamic contrast-enhanced MRI (DCE MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Savvopoulou, Vasiliki; Vlahos, Lampros; Moulopoulos, Lia Angela [University of Athens, Areteion Hospital, Department of Radiology, Medical School, Athens (Greece); Maris, Thomas G. [University of Crete, Deparment of Medical Physics, Faculty of Medicine, Heraklion (Greece)

    2008-09-15

    To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males. (orig.)

  18. To Evaluate the Damage of Renal Function in CIAKI Rats at 3T: Using ASL and BOLD MRI

    Directory of Open Access Journals (Sweden)

    Wen-bo Chen

    2015-01-01

    Full Text Available Purpose. To investigate noninvasive arterial spin-labeling (ASL and blood oxygen level-dependent imaging (BOLD sequences for measuring renal hemodynamics and oxygenation in contrast induced acute kidney injury (CIAKI rat. Materials and Methods. Thirteen SD rats were randomly grouped into CIAKI group and control group. Both ASL and BOLD sequences were performed at 24 h preinjection and at intervals of 0.5, 12, 24, 48, 72, and 96 h postinjection to assess renal blood flow (RBF and relative spin-spin relaxation rate (R2*, respectively. Results. For the CIAKI group, the value of RBF in the cortex (CO and outer medulla (OM of the kidney was significantly decreased (P<0.05 at 12–48 h and regressed to baseline level (P=NS at 72–96 h. In OM, the value of R2* was increased at 0.5–48 h (P<0.05 and not statistically significant (P=NS at 72 and 96 h. Conclusions. RBF in OM and CO and oxygen level in OM were decreased postinjection of CM. ASL combining BOLD can further identify the primary cause of the decrease of renal oxygenation in CIAKI. This approach provides means for noninvasive monitoring renal function during the first 4 days of CIAKI in clinical routine work.

  19. Contrast-enhanced 3D MRI of lung perfusion in children with cystic fibrosis - initial results

    International Nuclear Information System (INIS)

    This paper is a feasibility study of magnetic resonance imaging (MRI) of lung perfusion in children with cystic fibrosis (CF) using contrast-enhanced 3D MRI. Correlation assessment of perfusion changes with structural abnormalities. Eleven CF patients (9 f, 2 m; median age 16 years) were examined at 1.5 T. Morphology: HASTE coronal, transversal (TR/TE/α/ST: 600 ms/28 ms/180 /6 mm), breath-hold 18 s. Perfusion: Time-resolved 3D GRE pulse sequence (FLASH, TE/TR/α: 0.8/1.9 ms/40 ), parallel imaging (GRAPPA, PAT 2). Twenty-five data sets were acquired after intravenous injection of 0.1 mmol/kg body weight of gadodiamide, 3-5 ml/s. A total of 198 lung segments were analyzed by two radiologists in consensus and scored for morphological and perfusion changes. Statistical analysis was performed by Mantel-Haenszel chi-square test. Results showed that perfusion defects were observed in all patients and present in 80% of upper, and 39% of lower lobes. Normal lung parenchyma showed homogeneous perfusion (86%, P<0.0001). Severe morphological changes led to perfusion defects (97%, P<0.0001). Segments with moderate morphological changes showed normal (53%) or impaired perfusion (47%). In conclusion, pulmonary perfusion is easy to judge in segments with normal parenchyma or severe changes. In moderately damaged segments, MRI of lung perfusion may help to better assess actual functional impairment. Contrast-enhanced 3D MRI of lung perfusion has the potential for early vascular functional assessment and therapy control in CF patients. (orig.)

  20. Altered resting-state functional connectivity in post-traumatic stress disorder: a perfusion MRI study

    Science.gov (United States)

    Li, Baojuan; Liu, Jian; Liu, Yang; Lu, Hong-Bing; Yin, Hong

    2013-03-01

    The majority of studies on posttraumatic stress disorder (PTSD) so far have focused on delineating patterns of activations during cognitive processes. Recently, more and more researches have started to investigate functional connectivity in PTSD subjects using BOLD-fMRI. Functional connectivity analysis has been demonstrated as a powerful approach to identify biomarkers of different brain diseases. This study aimed to detect resting-state functional connectivity abnormities in patients with PTSD using arterial spin labeling (ASL) fMRI. As a completely non-invasive technique, ASL allows quantitative estimates of cerebral blood flow (CBF). Compared with BOLD-fMRI, ASL fMRI has many advantages, including less low-frequency signal drifts, superior functional localization, etc. In the current study, ASL images were collected from 10 survivors in mining disaster with recent onset PTSD and 10 survivors without PTSD. Decreased regional CBF in the right middle temporal gyrus, lingual gyrus, and postcentral gyrus was detected in the PTSD patients. Seed-based resting-state functional connectivity analysis was performed using an area in the right middle temporal gyrus as region of interest. Compared with the non-PTSD group, the PTSD subjects demonstrated increased functional connectivity between the right middle temporal gyrus and the right superior temporal gyrus, the left middle temporal gyrus. Meanwhile, decreased functional connectivity between the right middle temporal gyrus and the right postcentral gyrus, the right superior parietal lobule was also found in the PTSD patients. This is the first study which investigated resting-state functional connectivity in PTSD using ASL images. The results may provide new insight into the neural substrates of PTSD.

  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. Development and Applications of Velocity Selectivity in MRI

    OpenAIRE

    Guo, Jia

    2014-01-01

    Magnetic resonance imaging (MRI) is a powerful and noninvasive tool for measuring brain physiology and functions, including mapping perfusion and oxygen metabolism. Arterial spin labeling (ASL) uses magnetically labeled arterial blood water as an endogenous contrast agent to map regional perfusion. Velocity-selective ASL (VSASL) labels arterial water based on the flow velocity instead of location, eliminating the need for a spatial gap and associated heterogeneous transit delays (TDs) encount...

  3. Pro-angiogenic cellular and genomic expression patterns within glioblastoma influences dynamic susceptibility weighted perfusion MRI

    International Nuclear Information System (INIS)

    Aim: To investigate whether quantitative dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) metrics are influenced by cellular and genomic expression patterns of glioblastoma angiogenesis. Materials and methods: Twenty-five stereotactic neurosurgical tissue samples were prospectively obtained from enhancing and non-enhancing tumour regions from 10 patients with treatment-naïve glioblastoma. Using monoclonal antibodies, histopathological features of angiogenesis were examined: total microvascular density, vascular morphology, and hypoxia. Angiogenic expression patterns of tissue samples were investigated using RNA microarrays. DSC perfusion MRI metrics were measured from the tissue sampling sites. MRI and histopathological variables were compared using Pearson's correlations. Microarray analysis was performed using false discovery rate (FDR) statistics. Results: Thirteen enhancing and 12 non-enhancing MR image-guided tissue specimens were prospectively obtained. Enhancing tumour regions demonstrated a significant difference in DSC perfusion and histopathological metrics of angiogenesis when compared to non-enhancing regions. Four angiogenic pathways (vascular endothelial growth factor [VEGF], hypoxia inducible factor [HIF], platelet-derived growth factor [PDGF], fibroblast growth factor [FGF]; 25 individual genes) were significantly up-regulated within enhancing regions when compared to non-enhancing regions (adjusted p<0.05, FDR <0.05). A statistically significant correlation was observed between VEGF-A expression, microvascular density, microvascular morphology, and DSC perfusion MRI metrics (p<0.05). Conclusion: Pro-angiogenic genomic and cellular expression patterns of treatment-naïve primary glioblastoma significantly influences morphological and physiological DSC perfusion metrics suggesting that expression levels of therapeutically relevant genetic signatures can be quantified using MRI. -- Highlights:

  4. Suppression of pulmonary vasculature in lung perfusion MRI using correlation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Risse, Frank; Semmler, Wolfhard [Deutsches Krebsforschungszentrum, Department of Medical Physics in Radiology, Heidelberg (Germany); Kuder, Tristan A. [Deutsches Krebsforschungszentrum, Department of Medical Physics in Radiology, Heidelberg (Germany); Deutsches Krebsforschungszentrum, Department of Radiology, Heidelberg (Germany); Kauczor, Hans-Ulrich [University of Heidelberg, Department of Diagnostic Radiology, Heidelberg (Germany); Fink, Christian [University Medical Center Mannheim, Medical Faculty Mannheim - University of Heidelberg, Department of Clinical Radiology and Nuclear Medicine, Mannheim (Germany); Universitaetsmedizin Mannheim, Institut fuer Klinische Radiologie und Nuklearmedizin, Mannheim (Germany)

    2009-11-15

    The purpose of the study was to evaluate the feasibility of suppressing the pulmonary vasculature in lung perfusion MRI using cross-correlation analysis (CCA). Perfusion magnetic resonance imaging (MRI) (3D FLASH, TR/TE/flip angle: 0.8 ms/2.1 ms/40 ) of the lungs was performed in seven healthy volunteers at 1.5 Tesla after injection of Gd-DTPA. CCA was performed pixel-wise in lung segmentations using the signal time-course of the main pulmonary artery and left atrium as references. Pixels with high correlation coefficients were considered as arterial or venous and excluded from further analysis. Quantitative perfusion parameters [pulmonary blood flow (PBF) and volume (PBV)] were calculated for manual lung segmentations separately, with the entire left and right lung with all intrapulmonary vessels (IPV) included, excluded manually or excluded using CCA. The application of CCA allowed reliable suppression of hilar and large IPVs. Using vascular suppression by CCA, perfusion parameters were significantly reduced (p {<=} 0.001). The reduction was 8% for PBF and 13% for PBV compared with manual exclusion and 15% for PBF and 25% for PBV when all vessel structures were included. The application of CCA improves the visualisation and quantification of lung perfusion in MRI. Overestimation of perfusion parameters caused by pulmonary vessels is significantly reduced. (orig.)

  5. Motion-compensation of Cardiac Perfusion MRI using a Statistical Texture Ensemble

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsson, Henrik B. W.

    2003-01-01

    This paper presents a novel method for segmentation of cardiac perfusion MRI. By performing complex analyses of variance and clustering in an annotated training set off-line, the presented method provide real-time segmentation in an on-line setting. This renders the method feasible for e.g. analy......This paper presents a novel method for segmentation of cardiac perfusion MRI. By performing complex analyses of variance and clustering in an annotated training set off-line, the presented method provide real-time segmentation in an on-line setting. This renders the method feasible for e...

  6. New method for 3D parametric visualization of contrast-enhanced pulmonary perfusion MRI data

    Energy Technology Data Exchange (ETDEWEB)

    Kuder, Tristan A.; Eichinger, Monika; Ley, Sebastian; Puderbach, Michael; Kauczor, Hans-Ulrich [Deutsches Krebsforschungszentrum, Department of Radiology, E010, Heidelberg (Germany); Risse, Frank [Deutsches Krebsforschungszentrum, Department of Medical Physics in Radiology, Heidelberg (Germany); Fink, Christian [Deutsches Krebsforschungszentrum, Department of Radiology, E010, Heidelberg (Germany); Medical Faculty Mannheim - University of Heidelberg, Department of Clinical Radiology, University Hospital Mannheim, Mannheim (Germany)

    2008-02-15

    Three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (3D DCE-MRI) has been proposed for the assessment of regional perfusion. The aim of this work was the implementation of an algorithm for a 3D parametric visualization of lung perfusion using different cutting planes and volume rendering. Our implementation was based on 3D DCE-MRI data of the lungs of five patients and five healthy volunteers. Using the indicator dilution theory, the regional perfusion parameters, tissue blood flow, blood volume and mean transit time were calculated. Due to the required temporal resolution, the volume elements of dynamic MR data sets show a reduced spatial resolution in the z-direction. Therefore, perfusion parameter volumes were interpolated. Linear interpolation and a combination of linear and nearest-neighbor interpolation were evaluated. Additionally, ray tracing was applied for 3D visualization. The linear interpolation algorithm caused interpolation errors at the lung borders. Using the combined interpolation, visualization of perfusion information in arbitrary cutting planes and in 3D using volume rendering was possible. This facilitated the localization of perfusion deficits compared with the coronal orientated source data. The 3D visualization of perfusion parameters using a combined interpolation algorithm is feasible. Further studies are required to evaluate the additional benefit from the 3D visualization. (orig.)

  7. 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

  8. Impact of severe extracranial ICA stenosis on MRI perfusion and diffusion parameters in acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Philipp eKaesemann

    2014-12-01

    Full Text Available Purpose:The aim of this study was to investigate the impact of a coexisting internal carotid artery (ICA stenosis on lesion volumes as well as diffusion and perfusion parameters in acute ischemic stroke resulting from middle cerebral artery (MCA occlusion.Material and Methods:MRI data of 32 patients with MCA occlusion with or without additional ICA stenosis imaged within 4.5 hours of symptom onset were analyzed. Both groups consisted of 16 patients. Acute diffusion lesions were semi-automatically segmented in apparent diffusion coefficient (ADC MRI datasets. Perfusion maps of cerebral blood volume (CBV, cerebral blood flow (CBF, mean transit time (MTT and Tmax were calculated using perfusion-weighted MRI datasets. Tissue-at-risk (TAR volumes were generated by subtracting the ADC lesion from the hypoperfusion lesion defined by Tmax >6s. Median ADC and perfusion parameter values were extracted separately for the diffusion lesion and tissue-at-risk and used for statistical analysis.Results:No significant differences were found between the groups regarding the diffusion lesion and tissue-at-risk volumes. Statistical analysis of diffusion and perfusion parameters revealed CBV as the only parameter with a significant difference (p=0.009 contributing a small effect (ɛ²=0.11 to the group comparison with higher CBV values for the patient group with a coexisting ICA stenosis, while no significant effects were found for the other diffusion and perfusion parameters analyzed.Conclusion:The results of this study suggest that a coexisting ICA stenosis does not have a strong effect on tissue status or perfusion parameters in acute stroke patients except for a moderate elevation of CBV. This may reflect improved collateral circulation or ischemic preconditioning in patients with a pre-existing proximal stenosis balancing impaired perfusion from the stenosis.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  10. Motion-compensation of cardiac perfusion MRI using a statistical texture ensemble

    DEFF Research Database (Denmark)

    Stegmann, M.B.; Larsson, H.B.W.

    This paper presents a novel method for segmentation of cardiac perfusion MRI. By performing complex analyses of variance and clustering in an annotated training set off-line, the presented method provides real-time segmentation in an on-line setting. This renders the method feasible for e.g. anal...

  11. Unsupervised motion-compensation of multi-slice cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, M.B.; Ólafsdóttir, H; Larsson, H.B.W.

    2005-01-01

    This paper presents a novel method for registration of single and multi-slice cardiac perfusion MRI. Utilising off-line computer intensive analyses of variance and clustering in an annotated training set, the presented method is capable of providing registration without any manual interaction in ...

  12. Arterial spin labeling perfusion MRI in cerebral ischaemia

    NARCIS (Netherlands)

    Bokkers, R.P.H.

    2011-01-01

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

  13. 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.

  14. 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

  15. Unsupervised motion-compensation of multi-slice cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Ólafsdóttir, Hildur; Larsson, Henrik B. W.

    2005-01-01

    This paper presents a novel method for registration of single and multi-slice cardiac perfusion MRI. Utilising computer intensive analyses of variance and clustering in an annotated training set off-line, the presented method is capable of providing registration without any manual interaction...... is verified and stabilised using perfusion specific prior models of pose and shape estimated from training data. Qualitative and quantitative validation of the method is carried out using 2000 clinical quality, short-axis, perfusion MR slice images, acquired from ten freely breathing patients with acute...... myocardial infarction. Despite evident perfusion deficits and varying image quality in the limited training set, a leave-one-out cross validation of the method showed a mean point to curve distance of 1.25+/-0.36 pixels for the left and right ventricle combined. We conclude that this learning-based method...

  16. Diffusion and perfusion MRI for the localisation of epileptogenic foci in drug-resistant epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Heiniger, P.; El-Koussy, M.; Kiefer, C.; Oswald, H.; Schroth, G. [Department of Neuroradiology, Inselspital, Bern (Switzerland); Schindler, K.; Donati, F. [Department of Neurology, Inselspital, Bern (Switzerland); Loevblad, K.O. [Unite de Neuroradiologie, Service de Radiologie, Hopital Cantonal Universitaire HUG, Geneve (Switzerland); Department of Neuroradiology, Inselspital, Bern (Switzerland); Wissmeyer, M. [Department of Nuclear Medicine, Inselspital, Bern (Switzerland); Mariani, L. [Department of Neurosurgery, Inselspital, Bern (Switzerland); Weder, B. [Department of Neurology, Kantonsspital St. Gallen (Switzerland)

    2002-06-01

    Drug-resistant epilepsy is an important clinical challenge, both diagnostically and therapeutically. More and more surgical options are being considered, but precise presurgical assessment is necessary. We prospectively studied eight patients with drug-resistant epilepsy, who underwent clinical examination, single photon emission computed tomography (SPECT) and interictal MRI, including diffusion- and perfusion-weighted echoplanar sequences. Lesions suspected on SPECT of being epileptogenic showed mild hypoperfusion, while the diffusion-weighted MRI (DWI) revealed increased apparent diffusion coefficients relative to the other side. However, these abnormalities were not visible on the corresponding maps. We showed that DWI and perfusion-weighted MRI could be used confirm the characteristics and site of an epileptogenic area in patients with drug-resistant epilepsy. (orig.)

  17. Diffusion and perfusion MRI for the localisation of epileptogenic foci in drug-resistant epilepsy

    International Nuclear Information System (INIS)

    Drug-resistant epilepsy is an important clinical challenge, both diagnostically and therapeutically. More and more surgical options are being considered, but precise presurgical assessment is necessary. We prospectively studied eight patients with drug-resistant epilepsy, who underwent clinical examination, single photon emission computed tomography (SPECT) and interictal MRI, including diffusion- and perfusion-weighted echoplanar sequences. Lesions suspected on SPECT of being epileptogenic showed mild hypoperfusion, while the diffusion-weighted MRI (DWI) revealed increased apparent diffusion coefficients relative to the other side. However, these abnormalities were not visible on the corresponding maps. We showed that DWI and perfusion-weighted MRI could be used confirm the characteristics and site of an epileptogenic area in patients with drug-resistant epilepsy. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, H. (Den Sundhedsfaglige Kandidatuddannelse, Aarhus Universitet Bygning 1264, Aarhus (Denmark); University College Nordjylland, Aalborg (Denmark)), Email: hnt@ucn.dk; Steffensen, E. (Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark)); Larsson, E. M. (Aalborg Hospital/Aarhus University Hospital, Department of Radiology, Aalborg (Denmark); Uppsala University Hospital, Department of Radiology, Uppsala (Sweden))

    2012-02-15

    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 technique arterial spin labelling (ASL) presently provides measurement only of cerebral blood flow (CBF), which has not been widely used in human brain tumor studies. Purpose. To assess if measurement of blood flow is comparable with measurement of blood volume in human biopsy-proven gliomas obtained by DSC-MRI using two different regions for normalization and two different measurement approaches. Material and Methods. Retrospective study of 61 patients with different types of gliomas examined with DSC perfusion MRI. Regions of interest (ROIs) were placed in tumor portions with maximum perfusion on rCBF and rCBV maps, with contralateral normal appearing white matter and cerebellum as reference regions. Larger ROIs were drawn for histogram analyses. The type and grade of the gliomas were obtained by histopathology. Statistical comparison was made between diffuse astrocytomas, anaplastic astrocytomas, and glioblastomas. Results. rCBF and rCBV measurements obtained with the maximum perfusion method were correlated when normalized to white matter (r = 0.60) and to the cerebellum (r = 0.49). Histogram analyses of rCBF and rCBV showed that mean and median values as well as skewness and peak position were correlated (0.61 < r < 0.93), whereas for kurtosis and peak height, the correlation coefficient was about 0.3 when comparing rCBF and rCBV values for the same reference region. Neither rCBF nor rCBV quantification provided a statistically significant difference between the three types of gliomas. However, both rCBF and rCBV tended to increase with tumor grade and to be lower in patients who had undergone resection/treatment. Conclusion. rCBF measurements normalized to white matter

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-03-15

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

  20. Quantification of myocardial perfusion based on signal intensity of flow sensitized MRI

    Science.gov (United States)

    Abeykoon, Sumeda B.

    maximum percentage deviation is about 5%. Then the SI-method was used in comparison to a delayed enhanced method to qualitatively and quantitatively assess perfusion deficits in an ischemia-reperfusion (IR) mouse model. The infarcted region of the perfusion map is comparable to the hyper intense region of the delayed enhanced image of the IR mouse. The SI method also used to record a chronological comparison of perfusion on delta sarcoglycan null (DSG) mice. Perfusion of DSG and wild-type (WT) mice at ages of 12 weeks and 32 weeks were compared and percentage change of perfusion was estimated. The result shows that in DSG mice perfusion changes considerably. Finally, the SI method was implemented on a 3 Tesla Philip scanner by modifying to data acquisition method. The perfusion obtained in this is consistent with literature values but further adjustment of pulse sequence and modification of numerical solution is needed. The most important benefit of the SI method is that it reduces scan time 30%--40% and lessens motion artifacts of images compared to the T1 method. This study demonstrates that the signal intensity-based ASL method is a robust alternative to the conventional T1-method.

  1. Clinical, MRI and perfusion SPECT findings in strategic infarct dementia

    International Nuclear Information System (INIS)

    Strategic infarct dementia (SID) is characterized by focal ischemic lesions involving specific sites that are critical for higher cortical functions. The mechanism of SID are not well understood. We evaluate lesion sites, neuropsychiatric symptoms, brain perfusion SPECT and neuropsychological findings in patients with SID. Eleven patients with SID according to NINDS-AIREN criteria for vascular dementia were included. All patients performed brain MR and MRA, Tc-99m HMPAO brain perfusion SPECT. Various sites were responsible for SID; thalamus(n=3), medial temporal lobe(n=3), medial frontal lobe(n=1), genu of internal capsule(n=1), caudate nucleus(n=1), angular gyrus(n=1) and temporooccipital lobe(n=1). The most common neuropsychiatric symptoms were apathy and indifference by K-NPI. Brain perfusion SPECT revealed ipsilateral cortical hypoperfusion, mainly in frontal and temporal lobe area, in patients with subcortical strategic infarct. On neuropsychological assessment, cognitive deficits on attention and frontal executive function were prominent. The thalamus and medial temporal lobe were the most common sites responsible for SID. It was suggested that strategic disruption of frontal-subcortical circuit be an important role to produce SID in patients with subcortical strategic lesions

  2. Unusual MRI findings of dural arteriovenous fistula: Isolated perfusion lesions mimicking TIA

    Directory of Open Access Journals (Sweden)

    Kim Yong-Won

    2012-08-01

    Full Text Available Abstract Background The diagnosis of transient ischemic attack (TIA based on clinical history and objective findings, even including multiparametric MRI, can be misleading. We report two patients who presented with TIA-like deficits with isolated perfusion lesions in corresponding areas but were finally diagnosed as transient neurological symptoms associated with dural arteriovenous fistula (dAVF. Case presentation Two patients presented with transient focal neurological symptoms lasting less than one hour. An isolated perfusion deficit with no diffusion change in the clinically relevant area was shown on brain MRI, indicating transient ischemia as the most plausible cause of neurological symptoms. However, cerebral angiography let to diagnosis of dAVF in both cases. Intracerebral hemorrhage occurred after the initial diagnosis of TIA in one patient, and the small area of perfusion abnormality accompanied by the enlarged cortical vein in the other case helped to identify the dAVF through the further investigation. The pattern of perfusion-weighted imaging in both cases revealed increase of mean transit time and relative cerebral blood volume denoting the venous congestion in a clinically corresponding area. Conclusion Reported cases are uncommon clinical presentation of a dAVF, which can be misdiagnosed as TIA on clinical grounds. In rare cases, the isolated perfusion deficits could be attributable to venous congestion, despite the similar pattern of clinical presentation, such as with TIA.

  3. Value of dynamic susceptibility contrast perfusion MRI in the acute phase of transient global amnesia.

    Directory of Open Access Journals (Sweden)

    Alex Förster

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

  4. Diffusion- and perfusion-weighted MRI in a patient with a prolonged reversible ischaemic neurological deficit

    International Nuclear Information System (INIS)

    We report acute and follow-up diffusion- and perfusion-weighted MRI (DWI, PWI) findings in a patient with a prolonged reversible ischaemic neurological deficit. PWI 12 h after the patient was last seen to be without symptoms revealed a large perfusion deficit in the left posterior MCA territory with a relatively inconspicuous and much smaller abnormality on DWI. Follow-up showed resolution of abnormalities on both DWI and PWI, and conventional MRI was normal, apart from a very slight abnormality, visible only on FLAIR images, at the centre of the initially DWI-positive region. These findings demonstrate the utility of PWI when be used in combination with DWI to investigate the pathophysiology of transient ischemic syndromes. (orig.)

  5. [Pulmonary blood flow measurement using magnetic resonance imaging (MRI) without contrast medium;comparison of phase contrast MRI and perfusion-ventilation scintigraphy].

    Science.gov (United States)

    Yatsuyanagi, Eiji; Sato, Kazuhiro; Kikuchi, Keisuke; Saito, Hirotsugu

    2014-02-01

    To define the accuracy of pulmonary arterial blood flow (PA-flow) measured by phase contrast magnetic resonance imaging (PC-MRI), we compared the PA-flow data of PC-MRI with the data of perfusion-ventilation lung scintigraphy. Eighteen patients who preoperatively underwent PA-flow measurement using PC-MRI and perfusion-ventilation lung scintigraphy were evaluated. The PA-flow (cm3/sec) of MRI was calculated by multiplying maximum velocity (cm/sec) by region of interest (ROI) area (cm2) of measured main pulmonary artery using phase contrast method. The left to right ratio (R/L ratio) of PA-flow measured by PC-MRI was compared with the R/L ratios of the date of perfusion-ventilation lung scintigraphy. The R/L ratios of PC-MRI and perfusion lung scintigraphy were 1.43 ± 1.07 and 1.35 ± 0.82, respectively. Both ratios showed excellent correlation( y=-0.50+1.30x, r=0.99,pperfusion lung scintigraphy in the patients with a past history of lung resection, even if their R/L ratios of perfusion lung scintigraphy differed from those of ventilation lung scintigraphy. These results revealed that the PA-flow could be accurately measured by PC-MRI without contrast medium and nuclear medicine instruments.

  6. Sub-band denoising and spline curve fitting method for hemodynamic measurement in perfusion MRI

    Science.gov (United States)

    Lin, Hong-Dun; Huang, Hsiao-Ling; Hsu, Yuan-Yu; Chen, Chi-Chen; Chen, Ing-Yi; Wu, Liang-Chi; Liu, Ren-Shyan; Lin, Kang-Ping

    2003-05-01

    In clinical research, non-invasive MR perfusion imaging is capable of investigating brain perfusion phenomenon via various hemodynamic measurements, such as cerebral blood volume (CBV), cerebral blood flow (CBF), and mean trasnit time (MTT). These hemodynamic parameters are useful in diagnosing brain disorders such as stroke, infarction and periinfarct ischemia by further semi-quantitative analysis. However, the accuracy of quantitative analysis is usually affected by poor signal-to-noise ratio image quality. In this paper, we propose a hemodynamic measurement method based upon sub-band denoising and spline curve fitting processes to improve image quality for better hemodynamic quantitative analysis results. Ten sets of perfusion MRI data and corresponding PET images were used to validate the performance. For quantitative comparison, we evaluate gray/white matter CBF ratio. As a result, the hemodynamic semi-quantitative analysis result of mean gray to white matter CBF ratio is 2.10 +/- 0.34. The evaluated ratio of brain tissues in perfusion MRI is comparable to PET technique is less than 1-% difference in average. Furthermore, the method features excellent noise reduction and boundary preserving in image processing, and short hemodynamic measurement time.

  7. A Study on the Usefulness of Perfusion MRI in Grading of Gliomas

    International Nuclear Information System (INIS)

    To predict the tumor grading, various imaging modalities have been applied clinically. This study determines clinical usefulness of perfusion MRI, using relative cerebral blood volume in grading of the gliomas. We did a retrospective review of 17 patients (mean age, 57.5 years; 11 male, 6 female) who underwent perfusion MR and conventional MRI, and then correlated pathologically after operation. Statistical analysis of regional cerebral blood volume and relative cerebral blood volume(rCBV) was performed by using software such as PAT by SIEMENS and Xmap ver 2.0 developed by ourselves. Six patients out of 13 were low-grade gliomas while eleven patients were the high-grade gliomas. Mean relative CBV (mrCBV/white matter) in the low-grade gliomas was 1.62, and mean relative CBV(mrCBV/cortex) was 0.12. In the high-grade gliomas, mean relative CBV(mrCBV/white matter) and mean relative CBV(mrCBV/cortex) were 33.53 and 0.96. Mean relative CBV of gliomas were elevated with a statistical difference(PrCBV/white matter) was much higher than mean relative CBV(mrCBV/cortex). Perfusion MRI using regional cerebral blood volume and rCBV is very useful imaging modality for grading the glioma.

  8. Contrast-enhanced CT- and MRI-based perfusion assessment for pulmonary diseases: basics and clinical applications.

    Science.gov (United States)

    Ohno, Yoshiharu; Koyama, Hisanobu; Lee, Ho Yun; Miura, Sachiko; Yoshikawa, Takeshi; Sugimura, Kazuro

    2016-01-01

    Assessment of regional pulmonary perfusion as well as nodule and tumor perfusions in various pulmonary diseases are currently performed by means of nuclear medicine studies requiring radioactive macroaggregates, dual-energy computed tomography (CT), and dynamic first-pass contrast-enhanced perfusion CT techniques and unenhanced and dynamic first-pass contrast enhanced perfusion magnetic resonance imaging (MRI), as well as time-resolved three-dimensional or four-dimensional contrast-enhanced magnetic resonance angiography (MRA). Perfusion scintigraphy, single-photon emission tomography (SPECT) and SPECT fused with CT have been established as clinically available scintigraphic methods; however, they are limited by perfusion information with poor spatial resolution and other shortcomings. Although positron emission tomography with 15O water can measure absolute pulmonary perfusion, it requires a cyclotron for generation of a tracer with an extremely short half-life (2 min), and can only be performed for academic purposes. Therefore, clinicians are concentrating their efforts on the application of CT-based and MRI-based quantitative and qualitative perfusion assessment to various pulmonary diseases. This review article covers 1) the basics of dual-energy CT and dynamic first-pass contrast-enhanced perfusion CT techniques, 2) the basics of time-resolved contrast-enhanced MRA and dynamic first-pass contrast-enhanced perfusion MRI, and 3) clinical applications of contrast-enhanced CT- and MRI-based perfusion assessment for patients with pulmonary nodule, lung cancer, and pulmonary vascular diseases. We believe that these new techniques can be useful in routine clinical practice for not only thoracic oncology patients, but also patients with different pulmonary vascular diseases.

  9. Contrast-enhanced CT- and MRI-based perfusion assessment for pulmonary diseases: basics and clinical applications.

    Science.gov (United States)

    Ohno, Yoshiharu; Koyama, Hisanobu; Lee, Ho Yun; Miura, Sachiko; Yoshikawa, Takeshi; Sugimura, Kazuro

    2016-01-01

    Assessment of regional pulmonary perfusion as well as nodule and tumor perfusions in various pulmonary diseases are currently performed by means of nuclear medicine studies requiring radioactive macroaggregates, dual-energy computed tomography (CT), and dynamic first-pass contrast-enhanced perfusion CT techniques and unenhanced and dynamic first-pass contrast enhanced perfusion magnetic resonance imaging (MRI), as well as time-resolved three-dimensional or four-dimensional contrast-enhanced magnetic resonance angiography (MRA). Perfusion scintigraphy, single-photon emission tomography (SPECT) and SPECT fused with CT have been established as clinically available scintigraphic methods; however, they are limited by perfusion information with poor spatial resolution and other shortcomings. Although positron emission tomography with 15O water can measure absolute pulmonary perfusion, it requires a cyclotron for generation of a tracer with an extremely short half-life (2 min), and can only be performed for academic purposes. Therefore, clinicians are concentrating their efforts on the application of CT-based and MRI-based quantitative and qualitative perfusion assessment to various pulmonary diseases. This review article covers 1) the basics of dual-energy CT and dynamic first-pass contrast-enhanced perfusion CT techniques, 2) the basics of time-resolved contrast-enhanced MRA and dynamic first-pass contrast-enhanced perfusion MRI, and 3) clinical applications of contrast-enhanced CT- and MRI-based perfusion assessment for patients with pulmonary nodule, lung cancer, and pulmonary vascular diseases. We believe that these new techniques can be useful in routine clinical practice for not only thoracic oncology patients, but also patients with different pulmonary vascular diseases. PMID:27523813

  10. 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.)

  11. Assesment of perfusion in glial tumors with arterial spin labeling; comparison with dynamic susceptibility contrast method

    Energy Technology Data Exchange (ETDEWEB)

    Cebeci, H, E-mail: hcebeci16@gmail.com [Department of Radiology, Uludag University Medical School, Bursa (Turkey); Aydin, O [Department of Radiology, Uludag University Medical School, Bursa (Turkey); Ozturk-Isik, E; Gumus, C [Department of Biomedical Engineering, Yeditepe University, Istanbul (Turkey); Inecikli, F [Department of Radiology, Kanuni Sultan Suleyman Educational and Research Hospital, Istanbul (Turkey); Bekar, A; Kocaeli, H [Department of Neurosurgery, Uludag University Medical School, Bursa (Turkey); Hakyemez, B [Department of Radiology, Uludag University Medical School, Bursa (Turkey)

    2014-10-15

    Highlights: • We compared the perfusion parameters obtained with both DSC and ASL perfusion imaging methods. • In ASL perfusion imaging, we also created quantitative CBF maps. • All patients included in the study had histopathological diagnose. • All MR examinations are done with 3T MR imaging system. - Abstract: Purpose: Arterial spin labeling perfusion imaging (ASL-PI) is a non-invasive perfusion imaging method that can be used for evaluation and quantification of cerebral blood flow (CBF). Aim of our study was to evaluating the efficiency of ASL in histopathological grade estimation of glial tumors and comparing findings with dynamic susceptibility contrast perfusion imaging (DSC-PI) method. Methods: This study involved 33 patients (20 high-grade and 13 low-grade gliomas). Multiphase multislice pulsed ASL MRI sequence and a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence were acquired for all the patients. For each patient, perfusion relative signal intensity (rSI), CBF and relative CBF (rCBF) on ASL-PI and relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) values on DSC-PI were determined. The relative signal intensity of each tumor was determined as the maximal SI within the tumor divided by SI within symetric region in the contralateral hemisphere on ASL-PI. rCBV and rCBF were calculated by deconvolution of an arterial input function. Relative values of the lesions were obtained by dividing the values to the normal appearing symmetric region on the contralateral hemisphere. For statistical analysis, Mann–Whitney ranksum test was carried out. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBF-ASL, rSI-ASL, rCBV and rCBF ratios and grade of gliomas. Their cut-off values permitting best discrimination was calculated. The correlation between rCBV, rCBF, rSI-ASL and rCBF-ASL and glioma grade was assessed using

  12. Brain Perfusion MRI Findings in Patients with Behcet’s Disease

    Directory of Open Access Journals (Sweden)

    Alpay Alkan

    2012-01-01

    Full Text Available Objective. To search brain perfusion MRI (pMRI changes in Behcet’s disease (BD with or without neurological involvement. Materials and Method. The pMRI were performed in 34 patients with BD and 16 healthy controls. Based on neurologic examination and post-contrast MRI, 12 patients were classified as Neuro-Behcet (group 1, NBD and 22 patients as BD without neurological involvement (group 2. Mean transit time (MTT, time to peak (TTP, relative cerebral blood volume (rCBV, and relative cerebral blood flow (rCBF were obtained and compared to those of healthy control group (group 3. Results. There was a significant difference in the MTT and rCBF within the pons and parietal cortex in groups 1 and 2. rCBV increased in cerebral pedicle in group 1 compared with groups 2 and 3. In the temporal lobe white matter, prolonged MTT and decreased rCBF were found in groups 1 and 2. In the corpus striatum, internal capsule, and periventricular white matter, rCBF increased in group 1 compared with group 3 and decreased in groups 1 and 2. Conclusion. Brain pMRI is a very sensitive method to detect brain involvement in patients with BD and aids the clinical diagnosis of NBD, especially in patients with negative MRI findings.

  13. Automated scoring of regional lung perfusion in children from contrast enhanced 3D MRI

    Science.gov (United States)

    Heimann, Tobias; Eichinger, Monika; Bauman, Grzegorz; Bischoff, Arved; Puderbach, Michael; Meinzer, Hans-Peter

    2012-03-01

    MRI perfusion images give information about regional lung function and can be used to detect pulmonary pathologies in cystic fibrosis (CF) children. However, manual assessment of the percentage of pathologic tissue in defined lung subvolumes features large inter- and intra-observer variation, making it difficult to determine disease progression consistently. We present an automated method to calculate a regional score for this purpose. First, lungs are located based on thresholding and morphological operations. Second, statistical shape models of left and right children's lungs are initialized at the determined locations and used to precisely segment morphological images. Segmentation results are transferred to perfusion maps and employed as masks to calculate perfusion statistics. An automated threshold to determine pathologic tissue is calculated and used to determine accurate regional scores. We evaluated the method on 10 MRI images and achieved an average surface distance of less than 1.5 mm compared to manual reference segmentations. Pathologic tissue was detected correctly in 9 cases. The approach seems suitable for detecting early signs of CF and monitoring response to therapy.

  14. ASL and Bilingual Education.

    Science.gov (United States)

    Walworth, Margaret

    1989-01-01

    Explores the use of American Sign Language (ASL) in the bilingual instruction of English as a Second Language for deaf students. Issues addressed include dominant languages, language minorities, legislative and cultural recognition of ASL as an official language, and limited English proficiency. (CB) (Adjunct ERIC Clearinghouse on Literacy…

  15. Semi-quantitative assessment of pulmonary perfusion in children using dynamic contrast-enhanced MRI

    Science.gov (United States)

    Fetita, Catalin; Thong, William E.; Ou, Phalla

    2013-03-01

    This paper addresses the study of semi-quantitative assessment of pulmonary perfusion acquired from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in a study population mainly composed of children with pulmonary malformations. The automatic analysis approach proposed is based on the indicator-dilution theory introduced in 1954. First, a robust method is developed to segment the pulmonary artery and the lungs from anatomical MRI data, exploiting 2D and 3D mathematical morphology operators. Second, the time-dependent contrast signal of the lung regions is deconvolved by the arterial input function for the assessment of the local hemodynamic system parameters, ie. mean transit time, pulmonary blood volume and pulmonary blood flow. The discrete deconvolution method implements here a truncated singular value decomposition (tSVD) method. Parametric images for the entire lungs are generated as additional elements for diagnosis and quantitative follow-up. The preliminary results attest the feasibility of perfusion quantification in pulmonary DCE-MRI and open an interesting alternative to scintigraphy for this type of evaluation, to be considered at least as a preliminary decision in the diagnostic due to the large availability of the technique and to the non-invasive aspects.

  16. A comparison study of TCD vs MRI VE-ASL in the evaluation of collateral circulation of cerebral arter-ies%经颅多普勒超声与血管编码动脉自旋标记技术评价侧支循环的比较

    Institute of Scientific and Technical Information of China (English)

    彭清; 胡耀光; 叶长青; 吴冰; 黄一宁

    2014-01-01

    目的:比较经颅多普勒超声(transcranial Doppler,TCD)与血管编码动脉自旋标记(vessel-encoded arterial spin-labeling, VE-ASL)技术在评价单侧颈内动脉系统狭窄患者侧支循环情况中的作用。方法对TCD及颈部血管彩超检查诊断为单侧颈内动脉或大脑中动脉中度以上狭窄或闭塞的患者30例,行MRA及VE-ASL MRI检查。①记录TCD检测到的狭窄侧狭窄远端及非狭窄侧同一深度大脑中动脉收缩期峰值血流速度以及VE-ASL测量的狭窄侧和非狭窄侧大脑中动脉供血区的脑血流量。②比较TCD和VE-ASL MRI两种方法检测到的脑动脉侧支循环情况差异。结果①TCD检测的狭窄侧狭窄远端及非狭窄侧同一深度大脑中动脉收缩期峰值血流速度平均分别为(31.6±10.5) cm/s,(83.1±9.2) cm/s。VE-ASL测量的大脑中动脉供血区CBF值平均为狭窄侧(22.5±9.8) mL·min-1·100g-1,非狭窄侧(31.7±8.3) mL·min-1·100g-1。狭窄侧/非狭窄侧收缩期峰值血流速度比值明显低于狭窄侧/非狭窄侧大脑中动脉供血区CBF比值(0.37±0.173 vs.0.66±0.141, P=0.001)。②TCD侧支循环检出率明显低于VE-ASL,分别为前循环侧支检出率26.7%vs.70%(P=0.001),后循环侧支检出率16.7%vs.60%(P<0.001),总的脑侧支循环检出率36.7%vs.86.7%(P<0.001)。结论 TCD评价脑动脉侧支循环情况不如无创的VE-ASL,主要受限于Willis环解剖变异以及软脑膜动脉侧支循环的形成。%Objectives To evaluate the performances of transcranial Doppler (TCD) and vessel-encoded arterial spin labeling MRI perfusion imaging (VE-ASL) in the evaluation of collateral circulation of cerebral arteries. Methods Thirty patients with unilateral ICA or MCA stenosis diagnosed by TCD and carotid duplex ultrasound and confirmed by MRA underwent VE-ASL. Peak systolic velocity (PSV) of bilateral MCA in the same depth, distal to the stenosis site, was recorded. Cerebral blood flow

  17. 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.

  18. 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

  19. Focal status epilepticus: follow-up by perfusion- and diffusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    El-Koussy, M.; Loevblad, K.O.; Kiefer, C.; Schroth, G. [Department of Neuroradiology, University of Bern, Inselspital (Switzerland); Mathis, J.; Stepper, F. [Department of Neurology, University of Bern, Inselspital (Switzerland)

    2002-03-01

    Diffusion-weighted MRI demonstrated bright right temporoparietal cortex, right hippocampus, and left cerebellum in a 63-year-old female suffering a focal convulsive status epilepticus. Hyperperfusion was noted in the right temporoparietal region. Two days later, a tendency to normalization of most of the diffusion and perfusion changes was noted, apart from the right hippocampus which became brighter on diffusion- and T2-weighted images. On the tenth day the apparent diffusion coefficient was slightly elevated, getting brighter on T2-weighted images with suspected mild post-contrast enhancement. We postulate that the discharging right hippocampus suffered cytotoxic edema, which later progressed to cell damage. (orig.)

  20. Relationship between diffusion parameters derived from intravoxel incoherent motion MRI and perfusion measured by dynamic contrast-enhanced MRI of soft tissue tumors.

    Science.gov (United States)

    Marzi, Simona; Stefanetti, Linda; Sperati, Francesca; Anelli, Vincenzo

    2016-01-01

    Our aim was to evaluate the link between diffusion parameters measured by intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) and the perfusion metrics obtained with dynamic contrast-enhanced (DCE) MRI in soft tissue tumors (STTs). Twenty-eight patients affected by histopathologically confirmed STT were included in a prospective study. All patients underwent both DCE MRI and IVIM DWI. The perfusion fraction f, diffusion coefficient D and perfusion-related diffusion coefficient D* were estimated using a bi-exponential function to fit the DWI data. DCE MRI was acquired with a temporal resolution of 3-5 s. Maps of the initial area under the gadolinium concentration curve (IAUGC), time to peak (TTP) and maximum slope of increase (MSI) were derived using commercial software. The relationships between the DCE MRI and IVIM DWI measurements were assessed by Spearman's test. To exclude false positive results under multiple testing, the false discovery rate (FDR) procedure was applied. The Mann-Whitney test was used to evaluate the differences between all variables in patients with non-myxoid and myxoid STT. No significant relationship was found between IVIM parameters and any DCE MRI parameters. Higher f and D*f values were found in non-myxoid tumors compared with myxoid tumors (p = 0.004 and p = 0.003, respectively). MSI was significantly higher in non-myxoid tumors than in myxoid tumors (p = 0.029). From the visual assessments of single clinical cases, both f and D*f maps were in satisfactory agreement with DCE maps in the extreme cases of an avascular mass and a highly vascularized mass, whereas, for tumors with slight vascularity or with a highly heterogeneous perfusion pattern, this association was not straightforward. Although IVIM DWI was demonstrated to be feasible in STT, our data did not support evident relationships between perfusion-related IVIM parameters and perfusion measured by DCE MRI.

  1. Visual cortex reactivity in sedated children examined with perfusion MRI (FAIR)

    DEFF Research Database (Denmark)

    Born, A.P.; Rostrup, Egill; Miranda Gimenez-Ricco, Maria Jo;

    2002-01-01

    that it is caused by a relatively greater increase of oxygen consumption compared to rCBF (regional cerebral blood flow) increase. We studied the rCBF changes during visual stimulation in four sedated children, aged 4-71 months, and four alert adults, with an arterial water spin labeling technique (FAIR) and BOLD f......Sleeping and sedated children can respond to visual stimulation with a decrease in blood oxygenation level dependent (BOLD) functional MRI signal response. The contribution of metabolic and hemodynamic parameters to this inverse signal response is incompletely understood. It has been hypothesized.......99-2.93), respectively. Thus, in the children, an rCBF increase could not be detected by perfusion MRI, but indications of a FAIR signal decrease were found. An rCBF decrease in the primary visual cortex during stimulation has not been reported previously, but it is a possible explanation for the negative BOLD response...

  2. Quantification of the effect of water exchange in dynamic contrast MRI perfusion measurements in the brain and heart

    DEFF Research Database (Denmark)

    Larsson, H B; Rosenbaum, S; Fritz-Hansen, T

    2001-01-01

    Measurement of myocardial and brain perfusion when using exogenous contrast agents (CAs) such as gadolinium-DTPA (Gd-DTPA) and MRI is affected by the diffusion of water between compartments. This water exchange may have an impact on signal enhancement, or, equivalently, on the longitudinal...... exchange can have a significant effect on perfusion estimation (F) in the brain when using Gd-DTPA, where it acts as an intravascular contrast agent....

  3. Pulmonary functional MRI:an animal model study of oxygen-enhanced ventilation combined with Gd-DTPA-enhanced perfusion

    Institute of Scientific and Technical Information of China (English)

    杨健; 万明习; 郭佑民

    2004-01-01

    Background The assessment of regional pulmonary ventilation and perfusion is essential for the evaluation of a variety of lung disorders. Pulmonary ventilation MRI using inhaled oxygen as a contrast medium can be obtained with a clinical MR scanner, without additional equipment, and has been demonstrated to be a feasible means of assessing ventilation in animal models and some clinical patients. However, few studies have reported on MR ventilation-perfusion imaging. In this study, we evaluated the usefulness of oxygen-enhanced ventilation in combination with first-pass Gd-DTPA-enhanced perfusion MRI in a canine model of pulmonary embolism and airway obstruction.Methods Peripheral pulmonary embolisms were produced in eight dogs by intravenous injection of gelfoam strips at the pulmonary segmental arterial level, and airway obstructions were created in five of the dogs by inserting a self-designed balloon catheter into a secondary bronchus. Oxygen-enhanced MR ventilation images were produced by subtracting images from before and after inhalation of pure oxygen. Pulmonary perfusion MR images were acquired with a dynamic three-dimensional fast gradient-echo sequence. MR ventilation and perfusion images were read and contrasted with results from general examinations of pathological anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography. Results Regions identified as having airway obstructions matched using both MR ventilation and perfusion imaging, but regions of pulmonary embolisms were mismatched. The area of airway obstruction defects was smaller using MR ventilation imagery than that using ventilation scintigraphy. Abnormal perfusion regions due to pulmonary embolisms were divided into defective regions and reduced regions based on the time course of signal intensity changes. In the diagnosis of pulmonary embolisms with the technique of ventilation and perfusion MRI, sensitivity and specificity were 75.0% and 98.1%, respectively, and the diagnostic

  4. The correlation of contrast-enhanced ultrasound and MRI perfusion quantitative analysis in rabbit VX2 liver cancer.

    Science.gov (United States)

    Xiang, Zhiming; Liang, Qianwen; Liang, Changhong; Zhong, Guimian

    2014-12-01

    Our objective is to explore the value of liver cancer contrast-enhanced ultrasound (CEUS) and MRI perfusion quantitative analysis in liver cancer and the correlation between these two analysis methods. Rabbit VX2 liver cancer model was established in this study. CEUS was applied. Sono Vue was applied in rabbits by ear vein to dynamically observe and record the blood perfusion and changes in the process of VX2 liver cancer and surrounding tissue. MRI perfusion quantitative analysis was used to analyze the mean enhancement time and change law of maximal slope increasing, which were further compared with the pathological examination results. Quantitative indicators of liver cancer CEUS and MRI perfusion quantitative analysis were compared, and the correlation between them was analyzed by correlation analysis. Rabbit VX2 liver cancer model was successfully established. CEUS showed that time-intensity curve of rabbit VX2 liver cancer showed "fast in, fast out" model while MRI perfusion quantitative analysis showed that quantitative parameter MTE of tumor tissue increased and MSI decreased: the difference was statistically significant (P 0.05). However, the quantitative parameter of them were significantly positively correlated (P liver cancer lesion and surrounding liver parenchyma, and the quantitative parameters of them are correlated. The combined application of both is of importance in early diagnosis of liver cancer.

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

    Science.gov (United States)

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

    2005-03-01

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

  6. Perfusion parameters in MRI of pancreas transplants; Perfusionsparameter in der MRT-Diagnostik von Pankreastransplantaten

    Energy Technology Data Exchange (ETDEWEB)

    Marx, C.; Koenig, M.; Heuser, L. [Bochum Univ. (Germany). Abt. fuer Radiologie und Nuklearmedizin; Lueck, R.; Klempnauer, J. [Bochum Univ. (Germany). Chirurgische Klinik

    2000-01-01

    Purpose: Evaluation of the role of perfusion parameters in the detection of circulatory disturbance and chronic rejection in patients after pancreas transplantation. Materials and Methods: 70 examinations of 39 patients after pancreas transplantation were performed. Using a dynamic gadolinium-enhanced Turbo-FLASH-sequence, we evaluated the perfusion parameters in a group of patients with chronic rejection, with circulatory disturbance, and in a control group with normal organ function. Results: There were statistically significant differences of the perfusion parameters in patients with chronic rejection and circulatory disturbance compared to the control group. Conclusion: Dynamic MRI can help detect patients with chronic rejection and circulatory disturbance and should therefore be part of the routine follow-up in patients after pancreas transplantation. (orig.) [German] Ziel: Beurteilung von Perfusionsparametern im Rahmen schneller MRT-Sequenzen zur Erkennung einer Organabstossung und einer Durchblutungsstoerung bei Patienten nach Pankreastransplantation. Material und Methode: 70 MRT-Untersuchungen an 39 Patienten mit einer Pankreastransplantation wurden durchgefuehrt. Anhand einer dynamischen Turbo-FLASH-Sequenz mit Kontrastmittel-Bolusinjektion wurden Perfusionsparameter der Organdurchblutung bei Patienten mit normaler Organfunktion, einer chron. Organabstossung und einer Durchblutungsstoerung des Organs ermittelt. Ergebnis: Es konnten statistisch signifikante Unterschiede der Perfusionsparameter der Patienten mit einer Organabstossung und einer Durchblutungsstoerung gegenueber dem Normalkollektiv gemessen werden. Schlussfolgerung: Die kontrastmittel-unterstuetzte dynamische Magnetresonanztomographie kann Patienten mit einer Organabstossung und mit Durchblutungsstoerungen nach Pankreastransplantation fruehzeitig entdecken. Sie sollte deshalb routinemaessig in der Verlaufskontrolle nach kombinierter Nieren-Pankreastransplantation eingesetzt werden. (orig.)

  7. Accelerating free breathing myocardial perfusion MRI using multi coil radial k − t SLR

    International Nuclear Information System (INIS)

    The clinical utility of myocardial perfusion MR imaging (MPI) is often restricted by the inability of current acquisition schemes to simultaneously achieve high spatio-temporal resolution, good volume coverage, and high signal to noise ratio. Moreover, many subjects often find it difficult to hold their breath for sufficiently long durations making it difficult to obtain reliable MPI data. Accelerated acquisition of free breathing MPI data can overcome some of these challenges. Recently, an algorithm termed as k − t SLR has been proposed to accelerate dynamic MRI by exploiting sparsity and low rank properties of dynamic MRI data. The main focus of this paper is to further improve k − t SLR and demonstrate its utility in considerably accelerating free breathing MPI. We extend its previous implementation to account for multi-coil radial MPI acquisitions. We perform k − t sampling experiments to compare different radial trajectories and determine the best sampling pattern. We also introduce a novel augmented Lagrangian framework to considerably improve the algorithm’s convergence rate. The proposed algorithm is validated using free breathing rest and stress radial perfusion data sets from two normal subjects and one patient with ischemia. k − t SLR was observed to provide faithful reconstructions at high acceleration levels with minimal artifacts compared to existing MPI acceleration schemes such as spatio-temporal constrained reconstruction and k − t SPARSE/SENSE. (paper)

  8. Quantitative Myocardial Perfusion with Dynamic Contrast-Enhanced Imaging in MRI and CT: Theoretical Models and Current Implementation

    Directory of Open Access Journals (Sweden)

    G. J. Pelgrim

    2016-01-01

    Full Text Available Technological advances in magnetic resonance imaging (MRI and computed tomography (CT, including higher spatial and temporal resolution, have made the prospect of performing absolute myocardial perfusion quantification possible, previously only achievable with positron emission tomography (PET. This could facilitate integration of myocardial perfusion biomarkers into the current workup for coronary artery disease (CAD, as MRI and CT systems are more widely available than PET scanners. Cardiac PET scanning remains expensive and is restricted by the requirement of a nearby cyclotron. Clinical evidence is needed to demonstrate that MRI and CT have similar accuracy for myocardial perfusion quantification as PET. However, lack of standardization of acquisition protocols and tracer kinetic model selection complicates comparison between different studies and modalities. The aim of this overview is to provide insight into the different tracer kinetic models for quantitative myocardial perfusion analysis and to address typical implementation issues in MRI and CT. We compare different models based on their theoretical derivations and present the respective consequences for MRI and CT acquisition parameters, highlighting the interplay between tracer kinetic modeling and acquisition settings.

  9. Parametric response maps of perfusion MRI may identify recurrent glioblastomas responsive to bevacizumab and irinotecan.

    Directory of Open Access Journals (Sweden)

    Domenico Aquino

    Full Text Available Perfusion weighted imaging (PWI can be used to measure key aspects of tumor vascularity in vivo and recent studies suggest that perfusion imaging may be useful in the early assessment of response to angiogenesis inhibitors. Aim of this work is to compare Parametric Response Maps (PRMs with the Region Of Interest (ROI approach in the analysis of tumor changes induced by bevacizumab and irinotecan in recurrent glioblastomas (rGBM, and to evaluate if changes in tumor blood volume measured by perfusion MRI may predict clinical outcome.42 rGBM patients with KPS ≥ 50 were treated until progression, as defined by MRI with RANO criteria. Relative cerebral blood volume (rCBV variation after 8 weeks of treatment was calculated through semi-automatic ROI placement in the same anatomic region as in baseline. Alternatively, rCBV variations with respect to baseline were calculated into the evolving tumor region using a voxel-by-voxel difference. PRMs were created showing where rCBV significantly increased, decreased or remained unchanged.An increased blood volume in PRM (PRMCBV+ higher than 18% (first quartile after 8 weeks of treatment was associated with increased progression free survival (PFS; 24 versus 13 weeks, p = 0.045 and overall survival (OS; 38 versus 25 weeks, p = 0.016. After 8 weeks of treatment ROI analysis showed that mean rCBV remained elevated in non responsive patients (4.8 ± 0.9 versus 5.1 ± 1.2, p = 0.38, whereas decreased in responsive patients (4.2 ± 1.3 versus 3.8 ± 1.6 p = 0.04, and re-increased progressively when patients approached tumor progression.Our data suggest that PRMs can provide an early marker of response to antiangiogenic treatment and warrant further confirmation in a larger cohort of GBM patients.

  10. Factors in myocardial "perfusion" imaging with ultrafast MRI and Gd-DTPA administration.

    Science.gov (United States)

    Burstein, D; Taratuta, E; Manning, W J

    1991-08-01

    Ultrafast magnetic resonance imaging (MRI) and first pass observation of an interstitial contrast agent are currently being used to study myocardial perfusion. Image intensity, however, is a function of several parameters, including the delivery of the contrast agent to the interstitium (coronary flow rate and diffusion into the interstitium) and the relaxation properties of the tissue (contrast agent concentration, proton exchange rates, and relative intra- and extracellular volume fractions). In this study, image intensity during gadopentetate dimeglumine (Gd-DTPA) administration with T1-weighted ultrafast MR imaging was assessed in an isolated heart preparation. With increasing Gd-DTPA concentration, the steady-state myocardial image intensity increased but the time to reach steady state remained unchanged, resulting in an increased slope of image intensity change. A range of physiologic perfusion pressures (and resulting coronary flow rates) had insignificant effects on kinetics of Gd-DTPA wash-in or steady-state image intensity, suggesting that diffusion of Gd-DTPA into the interstitium is the rate limiting step in image intensity change with this preparation. Following global ischemia and reperfusion, transmural differences in the slope of image intensity change were apparent. However, the altered steady-state image intensity (due to postischemic edema) makes interpretation of this finding difficult. The studies described here demonstrate that although Gd-DTPA administration combined with ultrafast imaging may be a sensitive indicator of perfusion abnormalities, factors other than perfusion will affect image intensity. Extensive studies will be required before image intensity with this protocol is fully understood. PMID:1775055

  11. Comprehensive model for simultaneous MRI determination of perfusion and permeability using a blood-pool agent in rats rhabdomyosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Bazelaire, Cedric de [Saint Louis Hospital, Radiology Department, Paris (France); Siauve, Nathalie; Fournier, Laure; Clement, Olivier; Kerviler, Eric de; Cuenod, Charles Andre [George Pompidou European Hospital, Radiology Department, Paris (France); Frouin, Frederique [INSERM U494, Faculte de Medecine Pitie-Salpetriere, Paris (France); Robert, Philippe [Guerbet Laboratoire Guerbet, Recherche et Developpement, Paris (France)

    2005-12-01

    To present a new compartmental analysis model developed to simultaneously measure tissue perfusion and capillary permeability in a tumor using MRI and a macromolecular contrast medium. Rhadomyosarcomas were implanted subcutaneously in 20 rats and studied by 1.5-T MRI using a fast gradient echo sequence (2D fast SPGR TR/TE/{alpha} 13 ms/1.2 ms/60 ) after injection of a macromolecular contrast medium. The left ventricle and tumor signal intensities were converted into concentrations and modeled using compartmental analysis, yielding tumor perfusion F, distribution volume V{sub distribution}, volume transfer constant K{sup trans}, rate constant of influx k{sub pe}, and initial extraction (fraction) E. Tumor perfusion was F=43{+-}29 ml.min{sup -1}.100 g{sup -1}. The permeability study allowed the measurement of k{sub pe}=0.37{+-}0.12 min{sup -1} and K{sup trans}=0.01{+-}0.0031 min{sup -1}. The blood volume could be assimilated to the distribution volume (V{sub distribution}=2.9{+-}1.01%) since the capillary leakage was small. The simultaneous assessment of perfusion and permeability allowed quantification of the initial extraction (fraction) E=2.34{+-}1.05%. Quantification of both tumor perfusion and capillary leakage is feasible using MRI using a macromolecular blood pool agent. The method should improve tumor characterization. (orig.)

  12. Perfusion characteristics of late radiation injury of parotid glands: quantitative evaluation with dynamic contrast-enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Juan, Chun-Jung; Chen, Cheng-Yu.; Hsueh, Chun-Jen; Huang, Guo-Shu [Tri-Service General Hospital and National Defense Medical Center, Department of Radiology, Taipei (China); Jen, Yee-Min [Tri-Service General Hospital and National Defense Medical Center, Department of Radiation Oncology, Taipei (China); Liu, Hua-Shan; Wang, Chao-Ying; Chung, Hsiao-Wen [Tri-Service General Hospital and National Defense Medical Center, Department of Radiology, Taipei (China); National Taiwan University, Department of Electrical Engineering, Taipei (China); Liu, Yi-Jui [Feng Chia University, Department of Automatic Control Engineering, Taichung (China); Chou, Yu-Ching [National Defense Medical Center, School of Public Health, Taipei (China); Chai, Yao-Te [Hualien Armed Forces General Hospital, Section of General Surgery, Department of Surgery, Hualien (China)

    2009-01-15

    We aimed to quantitatively investigate the alteration of parotid perfusion after irradiation using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) based on a two-compartment tracer kinetic model. This study enrolled 19 patients (53.2{+-}14.9 years) treated by head and neck radiotherapy and 19 age-relevant and sex-matched subjects as a control group. Perfusion parameters (K{sub el}, k{sub 21} and A) of parotid glands were analyzed based on the Brix model from T1-weighted DCE-MRI. Suitability of the Brix model was evaluated via Monte Carlo simulation for the goodness-of-fit. Analysis of nonlinear goodness-of-fit showed that the Brix model is appropriate in evaluating the parotid perfusion (R {sup 2} = 0.938{+-}0.050). The irradiated parotid glands showed significantly lower K{sub el}(P<0.0005) and k{sub 21} (P < 0.05) and consequently significantly higher value of peak enhancement (P<0.0005) and time-to-peak (P<0.0005) compared with non-irradiated ones, suggestive of gradual and prolonged accumulation and delayed wash-out of contrast agent due to increased extracellular extravascular space and decreased vascular permeability in the irradiated glands. Linear regression analysis showed dose-dependent perfusion changes of the irradiated parotid glands. We conclude that quantitative DCE-MRI is a potential tool in investigating parotid gland perfusion changes after radiotherapy. (orig.)

  13. Temporal evolution of ischemic lesions in nonhuman primates: a diffusion and perfusion MRI study.

    Directory of Open Access Journals (Sweden)

    Xiaodong Zhang

    Full Text Available Diffusion-weighted imaging (DWI and perfusion MRI were used to examine the spatiotemporal evolution of stroke lesions in adult macaques with ischemic occlusion.Permanent MCA occlusion was induced with silk sutures through an interventional approach via the femoral artery in adult rhesus monkeys (n = 8, 10-21 years old. The stroke lesions were examined with high-resolution DWI and perfusion MRI, and T2-weighted imaging (T2W on a clinical 3T scanner at 1-6, 48, and 96 hours post occlusion and validated with H&E staining.The stroke infarct evolved via a natural logarithmic pattern with the mean infarct growth rate = 1.38 ± 1.32 ml per logarithmic time scale (hours (n = 7 in the hyperacute phase (1-6 hours. The mean infarct volume after 6 hours post occlusion was 3.6±2.8 ml (n = 7, by DWI and increased to 3.9±2.9 ml (n = 5, by T2W after 48 hours, and to 4.7±2.2ml (n = 3, by T2W after 96 hours post occlusion. The infarct volumes predicted by the natural logarithmic function were correlated significantly with the T2W-derived lesion volumes (n = 5, r = 0.92, p = 0.01 at 48 hours post occlusion. The final infarct volumes derived from T2W were correlated significantly with those from H&E staining (r = 0.999, p < 0.0001, n = 4. In addition, the diffusion-perfusion mismatch was visible generally at 6 hours but nearly diminished at 48 hours post occlusion.The infarct evolution follows a natural logarithmic pattern in the hyperacute phase of stroke. The logarithmic pattern of evolution could last up to 48 hours after stroke onset and may be used to predict the infarct volume growth during the acute phase of ischemic stroke. The nonhuman primate model, MRI protocols, and post data processing strategy may provide an excellent platform for characterizing the evolution of acute stroke lesion in mechanistic studies and therapeutic interventions of stroke disease.

  14. Perfusion MRI in hips with metal-on-metal and metal-on-polyethylene total hip arthroplasty

    OpenAIRE

    Anwander, H; Cron, G. O.; Rakhra, K.; Beaule, P. E.

    2016-01-01

    Objectives Hips with metal-on-metal total hip arthroplasty (MoM THA) have a high rate of adverse local tissue reactions (ALTR), often associated with hypersensitivity reactions. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measures tissue perfusion with the parameter Ktrans (volume transfer constant of contrast agent). Our purpose was 1) to evaluate the feasibility of DCE-MRI in patients with THA and 2) to compare DCE-MRI in patients with MoM bearings with metal-on-polyethyl...

  15. Correlation of histological findings from a large ciliochoroidal melanoma with CT perfusion and 3T MRI dynamic enhancement studies

    Directory of Open Access Journals (Sweden)

    Jose S Pulido

    2008-06-01

    Full Text Available Jose S Pulido1, Norbert G Campeau2, Ernst Klotz3, Andrew N Primak2, Osama Saba3, Kaan Gunduz1, Herbert Cantrill5, Diva Salomão1,4, Cynthia H McCollough21Department of Ophthalmology; 2Department of Radiology; 3Siemens Medical Solutions, Malvern, PA, USA; 4Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA; 5VitreoRetinal Surgery, Minneapolis, MN, USABackground: The initial use of a 64-slice computed tomography (CT scanner for obtaining quantitative perfusion data from a large ciliochoroidal melanoma, and correlation with 3T magnetic resonance imaging (MRI dynamic enhancement and tumor histology.Methods: The CT perfusion scan was performed using 80 kVp, 250 mA and 1-sec rotation time for 40 sec. The analysis was performed using commercial perfusion analysis software with a prototype 3-dimensional motion correction tool. Dynamic contrast-enhanced 3-Tesla MRI measured the kinetics of enhancement to estimate the vascular permeability. The time-dependent enhancement patterns were obtained using the average signal intensity using Functool analysis software. The involved globe was enucleated and microscopic evaluation of the tumor was performed.Results: The perfusion parameters blood flow, blood volume and permeability surface area product in the affected eye determined by CT perfusion analysis were 118 ml/100 ml/min, 11.3 ml/100 ml and 48 ml/100 ml/min. Dynamic MRI enhancement showed maximal intensity increase of 111%. The neoplasm was a ciliochoroidal spindle cell melanoma which was mitotically active (13 mitoses/40 hpf. Vascular loops and arcades were present throughout the tumor. The patient developed metastases within 9 months of presentation.Conclusion: Quantitative CT perfusion analysis of ocular tumors is feasible with motion correction software.Keywords: ciliochoroidal melanoma, CT perfusion imaging, MR enhancement imaging, tumor blood volume, tumor blood flow, tumor permeability

  16. Comparative utility of MRI perfusion with MSIDR and DWIBS for the characterization of breast tumors

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bing; Zhu, Bin; Li, Ming [Dept. of Radiology, The Drum Tower Hospital, Affiliate Hospital of Nanjing Univ. Medical School, Nanjing (China)], E-mail: 15851803070@163.com [and others

    2012-07-15

    Background. In recent years, breast magnetic resonance imaging (MRI) has been used to evaluate the morphology and functional markers of breast lesions, which might influence local staging and surgical planning. Purpose. To evaluate the feasibility of a one stop MRI protocol combined with diffusion-weighted imaging with background body signal suppression (DWIBS), T2*-weighted perfusion imaging (T2*-PWI) and delayed contrast-enhanced T1-weighted MRI (T1W-C+). Material and Methods. All experiments were conducted with a 3-T clinical MRI scanner. The apparent diffusion coefficient (ADC) and detectability of lesions in DWIBS, the maximal signal intensity drop rate (MSIDR) in T2*-PWI and the intensity increasing rate (IIR) on T1W-C+ were compared between breast malignancies (n = 29) and benign lesions (n = 31). The time-signal curves in the T2*-PWI sequences were classified into two subtypes (a and b) according to the end of the curve. The ADC, MSIDR, the first maximal signal intensity decrease time (MSIDT), and IIR between the malignant and benign lesions were statistically analyzed by unpaired t-tests. Results. Overall, 90% of the lesions were detected by DWIBS. There were significant differences in ADC, MSIDR, and IIR between the carcinomas and benign lesions. The Ib subtype in T2*-PWI demonstrated a specificity of 66.7% in differentiating between carcinomas and benign lesions. At a fixed specificity of 93.5%, the MSIDR, IIR, and ADC differentiated breast carcinomas from benign lesions with sensitivities of 82.8%, 44.8%, and 86.2%, respectively. Conclusion. DWIBS might be a compensation sequence for detecting breast lesions in pre-contrast sequences. MSIDR from T2*-PWI had the best specificity index, and the two subtypes in the T2*-PWI curve were helpful in the differential diagnosis of carcinomas from benign lesions.

  17. Usefulness of Permeability Map by Perfusion MRI of Brain Tumor the Grade Assessment

    International Nuclear Information System (INIS)

    This study was conducted to assess how effective the permeability ratio and relative cerebral blood volume ratio are to tumor through perfusion MRI by measuring and reflecting the grade assessment and differential diagnosis and the permeability and relative cerebral blood volume of contrast media plunged from blood vessel into organ due to breakdown of blood-brain barrier in cerebral. Subject and Method : Subject of study was 29 patients whose diagnosis were confirmed by biopsy after surgery and 550 (11 slice x 50 image) perfusion MRI were used to make image of relative cerebral blood volume with the program furnished on instrument. The other method was to transmit to private computer and the image analysis was made additionally by making image of relative cerebral blood volume-reformulated singular value decomposition, rCBV-rSVD and permeability using IDL.6.2. In addition, Kruskal-wallis test tonggyein non numerical average by a comparative analysis of brain tumors Results : The rCBV ratio (Functool PF; GE Medical Systems and IDL 6.2 program by analysis) and permeability ratio of tumors were as follows; high grade glioma(n=4), (14.75, 19.25) 13.13. low grade astrocytoma(n=5) (14.80, 15.90) 11.60, glioblastoma(n=5) (10.90, 18.60), 22.00, metastasis(n=6) (11.00, 15.08). 22.33. meningioma(n=6) (18.58, 7.67), 5.58. oliogodendroglioma(n=3) (23.33, 16.33, 15.67. Conclusion : It was not easy to classify the grade with the relative cerebral blood volume ratio measured by using the relative cerebral blood image by type of tumors, however, permeability ratio measured by permeability image revealed that the higher the grade of tumor, the higher the measured permeability ratio, showing the assessment of tumor grade is more effective to differential diagnosis.

  18. Usefulness of Permeability Map by Perfusion MRI of Brain Tumor the Grade Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sung Jin [Dept. of Radiology, Dongsan Hospital, Keimyung University, Daegu (Korea, Republic of); Lee, Joo Young [GE Healthcare, Seoul (Korea, Republic of); Chang, Hyuk Won [Dept. of Radiology, Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2009-09-15

    This study was conducted to assess how effective the permeability ratio and relative cerebral blood volume ratio are to tumor through perfusion MRI by measuring and reflecting the grade assessment and differential diagnosis and the permeability and relative cerebral blood volume of contrast media plunged from blood vessel into organ due to breakdown of blood-brain barrier in cerebral. Subject and Method : Subject of study was 29 patients whose diagnosis were confirmed by biopsy after surgery and 550 (11 slice x 50 image) perfusion MRI were used to make image of relative cerebral blood volume with the program furnished on instrument. The other method was to transmit to private computer and the image analysis was made additionally by making image of relative cerebral blood volume-reformulated singular value decomposition, rCBV-rSVD and permeability using IDL.6.2. In addition, Kruskal-wallis test tonggyein non numerical average by a comparative analysis of brain tumors Results : The rCBV ratio (Functool PF; GE Medical Systems and IDL 6.2 program by analysis) and permeability ratio of tumors were as follows; high grade glioma(n=4), (14.75, 19.25) 13.13. low grade astrocytoma(n=5) (14.80, 15.90) 11.60, glioblastoma(n=5) (10.90, 18.60), 22.00, metastasis(n=6) (11.00, 15.08). 22.33. meningioma(n=6) (18.58, 7.67), 5.58. oliogodendroglioma(n=3) (23.33, 16.33, 15.67. Conclusion : It was not easy to classify the grade with the relative cerebral blood volume ratio measured by using the relative cerebral blood image by type of tumors, however, permeability ratio measured by permeability image revealed that the higher the grade of tumor, the higher the measured permeability ratio, showing the assessment of tumor grade is more effective to differential diagnosis.

  19. 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...

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

    Directory of Open Access Journals (Sweden)

    Long Xie

    2016-01-01

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

  1. Visual cortex reactivity in sedated children examined with perfusion MRI (FAIR)

    DEFF Research Database (Denmark)

    Born, A P; Rostrup, E; Miranda, M J;

    2002-01-01

    that it is caused by a relatively greater increase of oxygen consumption compared to rCBF (regional cerebral blood flow) increase. We studied the rCBF changes during visual stimulation in four sedated children, aged 4-71 months, and four alert adults, with an arterial water spin labeling technique (FAIR) and BOLD f......MRI in a 1.5T MR scanner. In the children, FAIR signal decreased by a mean of 0.96% (range 0.77-1.05) of the baseline periods of the non-selective images, while BOLD signal decreased by 2.03% (range 1.99-2.93). In the adults, FAIR and BOLD signal increased by 0.88% (range 0.8-0.99) and 2.63% (range 1.......99-2.93), respectively. Thus, in the children, an rCBF increase could not be detected by perfusion MRI, but indications of a FAIR signal decrease were found. An rCBF decrease in the primary visual cortex during stimulation has not been reported previously, but it is a possible explanation for the negative BOLD response...

  2. Preliminary study of CT in combination with MRI perfusion imaging to assess hemodynamic changes during angiogenesis in a rabbit model of lung cancer

    Directory of Open Access Journals (Sweden)

    Zhang Q

    2013-06-01

    Full Text Available Qiang Zhang,1 Baoqi Shi,1 Zhaoxin Liu,1 Mingmin Zhang,1 Weijing Zhang21Radiology Department, Baotou Cancer Hospital, Inner Mongolia Autonomous Region, 2Department of Mathematics, College of Science, Beijing Institute of Technology, Beijing, People's Republic of ChinaBackground: This study used CT (computed tomography and magnetic resonance imaging (MRI to identify correlations between perfusion parameters for squamous cell lung carcinoma and tumor angiogenesis in a rabbit model of VX2 lung cancer.Methods: VX2 tumors were implanted in the lungs of 35 New Zealand White rabbits. CT and MRI perfusion scanning were performed on days 14, 17, 21, 25, and 28 after tumor implantation. CT perfusion parameters were perfusion, peak enhanced increment, transit time peak, and blood volume, and MRI perfusion parameters were wash in rate, wash out rate, maximum enhancement rate, and transit time peak. CT and MRI perfusion parameters were obtained at the tumor rim, in the tumor tissue, and in the muscle tissue surrounding the tumor.Results: On CT perfusion imaging, t values for perfusion, peak enhanced increment, and blood volume (tumor rim versus muscle were 16.31, 11.79, and 5.21, respectively (P 0.05. On MRI perfusion imaging, t values for wash in rate, wash out rate, and maximum enhancement rate (tumor rim versus muscle were 18.14, 8.79, and 6.02, respectively (P 0.05.Conclusion: A combination of CT and MRI perfusion imaging demonstrated hemodynamic changes in a rabbit model of VX2 lung cancer, and provides a theoretical foundation for treatment of human squamous cell lung carcinoma.Keywords: perfusion imaging, rabbits, animal model, lung, squamous carcinoma cell

  3. Dynamic contrast enhanced T1 MRI perfusion differentiates pseudoprogression from recurrent glioblastoma.

    Science.gov (United States)

    Thomas, Alissa A; Arevalo-Perez, Julio; Kaley, Thomas; Lyo, John; Peck, Kyung K; Shi, Weiji; Zhang, Zhigang; Young, Robert J

    2015-10-01

    Pseudoprogression may present as transient new or increasing enhancing lesions that mimic recurrent tumors in treated glioblastoma. The purpose of this study was to examine the utility of dynamic contrast enhanced T1 magnetic resonance imaging (DCE MRI) in differentiating between pseudoprogression and tumor progression and devise a cut-off value sensitive for pseudoprogression. We retrospectively examined 37 patients with glioblastoma treated with radiation and temozolomide after surgical resection that then developed new or increasing enhancing lesion(s) indeterminate for pseudoprogression versus progression. Volumetric plasma volume (Vp) and time-dependent leakage constant (Ktrans) maps were measured for the enhancing lesion and the mean and ninetieth percentile histogram values recorded. Lesion outcome was determined by clinical follow up with pseudoprogression defined as stable disease not requiring new treatment. Statistical analysis was performed with Wilcoxon rank-sum tests. Patients with pseudoprogression (n = 13) had Vp (mean) = 2.4 and Vp (90 %tile) = 3.2; and Ktrans (mean) = 3.5 and Ktrans (90 %tile) = 4.2. Patients with tumor progression (n = 24) had Vp (mean) = 5.3 and Vp (90 %tile) = 6.6; and Ktrans (mean) = 7.4 and Ktrans (90 %tile) = 9.1. Compared with tumor progression, pseudoprogression demonstrated lower Vp perfusion values (p = 0.0002) with a Vp (mean) cutoff mean) of >3.6 had a 69% sensitivity and 79% specificity for disease progression. DCE MRI shows lower plasma volume and time dependent leakage constant values in pseudoprogression than in tumor progression. A cut-off value with high sensitivity for pseudoprogression can be applied to aid in interpretation of DCE MRI.

  4. 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

  5. Contrast optimization in multiphase arterial spin labeling; Otimizacao do contraste em ASL multi-fase

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Fernando F.; Paschoal, Andre M., E-mail: paiva@ifsc.usp.br [Universidade de Sao Paulo (CIERMag/USP), Sao Carlos, SP (Brazil). Instituto de Fisica; Foerster, Bernd U. [Philips Medical Systems LatAm, Sao Paulo, SP (Brazil); Tovar-Moll, Fernanda; Moll, Jorge [Instituto D' Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil)

    2013-08-15

    Multiphase ASL is an effective way to overcome the regional variation of the transit time that difficult the estimation of perfusion values. However, with conventional multiple phases ASL techniques, the ASL contrast at later phases is impaired due to repeated application of excitation pulses and longitudinal relaxation making it difficult to evaluate the tissue perfusion in regions where the transit time is longer. In the present study, we show an improvement of the acquisition scheme by exploring a modulation on the flip angle of the MR acquisition to keep the ASL contrast constant over multiple phases. (author)

  6. Bevacizumab treatment in malignant meningioma with additional radiation necrosis. An MRI diffusion and perfusion case study

    Energy Technology Data Exchange (ETDEWEB)

    Bostroem, J.P. [University of Bonn Medical Center, Department of Neurosurgery, Bonn (Germany); MediClin Robert Janker Clinic and MVZ MediClin, Department of Radiosurgery and Stereotactic Radiotherapy, Bonn (Germany); Seifert, M.; Greschus, S. [University of Bonn Medical Center, Department of Radiology, Bonn (Germany); Schaefer, N.; Herrlinger, U. [University of Bonn Medical Center, Division of Clinical Neurooncology, Department of Neurology, Bonn (Germany); Glas, M. [University of Bonn Medical Center, Division of Clinical Neurooncology, Department of Neurology, Bonn (Germany); University of Bonn Medical Center, Stem Cell Pathologies, Institute of Reconstructive Neurobiology, Bonn (Germany); MediClin Robert Janker Clinic, Clinical Cooperation Unit Neurooncology, Bonn (Germany); Lammering, G. [MediClin Robert Janker Clinic and MVZ MediClin, Department of Radiosurgery and Stereotactic Radiotherapy, Bonn (Germany); MediClin Robert Janker Clinic, Clinical Cooperation Unit Neurooncology, Bonn (Germany); Heinrich-Heine-University of Duesseldorf, Department of Radiotherapy and Radiation Oncology, Duesseldorf (Germany)

    2014-04-15

    Recently two retrospective cohort studies report efficacy of bevacizumab in patients with recurrent atypical and anaplastic meningioma. Another successful therapeutic option of bevacizumab seems to be treatment of cerebral radiation necrosis. However, the antiangiogenic effects in MRI diffusion and perfusion in meningiomas have not been previously described in detail. The objective of this research was to evaluate the clinical and MR imaging effects of bevacizumab in a malignant meningioma patient harboring additional cerebral radiation necrosis. We report the case of an 80-year-old woman who underwent bevacizumab therapy (5 mg/kg every 2 weeks for 2 months) for treatment of a symptomatic radiation necrosis in malignant meningiomatosis of World Health Organization (WHO) grade III. The patient was closely monitored with MRI including diffusion and perfusion studies. Upon bevacizumab therapy, the clinical situation was well stabilized over a period of 4 months until the patient unfortunately died due to pneumonia/septicemia probably unrelated to bevacizumab therapy. Consecutive MRI demonstrated 4 important aspects: (1) considerable decrease of the contrast medium (CM)-enhanced radiation necrosis, (2) mixed response with respect to the meningiomatosis with stable and predominantly growing tumor lesions, (3) a new diffusion-weighted imaging (DWI) lesion in a CM-enhanced tumor as described in gliomas, which we did not interpret as a response to bevacizumab therapy, and (4) new thrombembolic infarcts, which are a known side-effect of bevacizumab treatment. Bevacizumab is effective in the treatment of radiation necrosis. We could not confirm the potential antitumor effect of bevacizumab in this patient. However, we could describe several new radiographic effects of bevacizumab therapy in malignant meningioma. (orig.) [German] In zwei aktuellen retrospektiven Kohortenstudien konnte eine Wirksamkeit von Bevacizumab bei Patienten mit rezidivierenden atypischen und

  7. Tumor classification using perfusion volume fractions in breast DCE-MRI

    Science.gov (United States)

    Lee, Sang Ho; Kim, Jong Hyo; Park, Jeong Seon; Park, Sang Joon; Jung, Yun Sub; Song, Jung Joo; Moon, Woo Kyung

    2008-03-01

    This study was designed to classify contrast enhancement curves using both three-time-points (3TP) method and clustering approach at full-time points, and to introduce a novel evaluation method using perfusion volume fractions for differentiation of malignant and benign lesions. DCE-MRI was applied to 24 lesions (12 malignant, 12 benign). After region growing segmentation for each lesion, hole-filling and 3D morphological erosion and dilation were performed for extracting final lesion volume. 3TP method and k-means clustering at full-time points were applied for classifying kinetic curves into six classes. Intratumoral volume fraction for each class was calculated. ROC and linear discriminant analyses were performed with distributions of the volume fractions for each class, pairwise and whole classes, respectively. The best performance in each class showed accuracy (ACC), 84.7% (sensitivity (SE), 100%; specificity (SP), 66.7% to a single class) to 3TP method, whereas ACC, 73.6% (SE, 41.7%; SP, 100% to a single class) to k-means clustering. The best performance in pairwise classes showed ACC, 75% (SE, 83.3%; SP, 66.7% to four class pairs and SE, 58.3%; SP, 91.7% to a single class pair) to 3TP method and ACC, 75% (SE, 75%; SP, 75% to a single class pair and SE, 66.7%; SP, 83.3% to three class pairs) to k-means clustering. The performance in whole classes showed ACC, 75% (SE, 83.3%; SP, 66.7%) to 3TP method and ACC, 75% (SE, 91.7%; 58.3%) to k-means clustering. The results indicate that tumor classification using perfusion volume fractions is helpful in selecting meaningful kinetic patterns for differentiation of malignant and benign lesions, and that two different classification methods are complementary to each other.

  8. Dynamic contrast-enhanced quantitative perfusion measurement of the brain using T-1-weighted MRI at 3T

    DEFF Research Database (Denmark)

    Larsson, H.B.W.; Hansen, A.E.; Berg, H.K.;

    2008-01-01

    Purpose: To develop a method for the measurement of brain perfusion based on dynamic contrast-enhanced T-1-weighted MR imaging. Materials and Methods: Dynamic imaging of the first pass of a bolus of a paramagnetic contrast agent was performed using a 3T whole-body magnet and a T-1-weighted fast...... field echo sequence. The input function was obtained from the internal carotid artery. An initial T-1 measurement was performed in order to convert the MR signal to concentration of the contrast agent. Pixelwise and region of interest (ROI)based calculation of cerebral perfusion (CBF) was performed...... inside the infarct core was, 9 mL/100g/min in one of the stroke patients. The other stroke patient had postischemic hyperperfusion and CBF was 140 mL/100g/min. Conclusion: Absolute values of brain perfusion can be obtained using dynamic contrast-enhanced MRI. These values correspond,to expected values...

  9. The importance of AIF ROI selection in DCE-MRI renography: Reproducibility and variability of renal perfusion and filtration

    Energy Technology Data Exchange (ETDEWEB)

    Cutajar, M., E-mail: m.cutajar@ich.ucl.ac.u [Radiology and Physics Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH (United Kingdom); Brighton and Sussex Medical School, University of Sussex, Brighton BN1 9PX (United Kingdom); Mendichovszky, I.A. [Imaging Science and Biomedical Engineering, University of Manchester, Manchester M13 9PT (United Kingdom); Tofts, P.S. [Brighton and Sussex Medical School, University of Sussex, Brighton BN1 9PX (United Kingdom); UCL Institute of Neurology, Queen Square, London WC1N 3BG (United Kingdom); Gordon, I. [Radiology and Physics Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH (United Kingdom)

    2010-06-15

    Purpose: The aim of this study was to investigate (a) the effect the choice of the region of interest (ROI) defining the aortic input function (AIF) has on the estimation of renal perfusion and filtration in dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) renography, and (b) the reproducibility of these parameters. Using renal DCE-MRI and a three-compartment model analysis, this work evaluated the effect two different AIFs, derived from variable sized ROIs in the aorta, has on calculating DCE-MRI renal perfusion and filtration values in a group of healthy adult volunteers who underwent two consecutive renal DCE-MRI studies. Methods: Fifteen healthy volunteers underwent two DCE-MRI studies under similar physiological conditions. Oblique-coronal DCE-MRI data volumes were acquired on a 1.5 T Siemens Avanto scanner with a 3D-FLASH pulse-sequence (TE/TR = 0.53/1.63 ms, flip angle = 17{sup o}, acquisition matrix = 128 x 104 voxels, strong fat saturation, PAT factor = 2 (GRAPPA) and 400 mm x 325 mm FOV). Each dynamic dataset consisted of 18 slices of 7.5 mm thickness (no gap) and an in-plane resolution of 3.1 mm x 3.1 mm, acquired every 2.5 s for not less than 5 minutes. During the MR scan a dose of 0.05 mmol (0.1 mL) kg{sup -1} body weight of dimeglumine gadopentetate (Magnevist) was injected intravenously (2 mL s{sup -1} injection rate), followed by a 15 mL saline flush at the same rate, using a MR-compatible automated injector (Spectris). Two AIFs were defined for each volunteer by drawing two ROIs in the aorta for each study. Renal perfusion and glomerular filtration rate (GFR) values were then calculated for each of the AIFs using a modified Tofts Renal Model (TRM). Both renal perfusion and GFR were expressed in mL min{sup -1} 100 mL{sup -1} of tissue. Results and conclusion: Inter-individual reproducibility tests for renal perfusion and glomerular filtration rate showed that the size of AIF ROIs significantly affects calculated values of perfusion

  10. 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

  11. Evaluation of dynamic contrast-enhanced T1-weighted perfusion MRI in the differentiation of tumor recurrence from radiation necrosis

    DEFF Research Database (Denmark)

    Larsen, Anne Vibeke Andrée; Simonsen, Helle J; Law, Ian;

    2013-01-01

    to measure cerebral blood volume (CBV), blood-brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used......INTRODUCTION: To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. METHODS: The study was approved by the institutional review board...

  12. Advances in Functional and Structural Imaging of the Human Lung Using Proton MRI

    OpenAIRE

    Miller, G. Wilson; Mugler, John P.; Sá, Rui C.; Altes, Talissa A.; Prisk, G. Kim; Hopkins, Susan R.

    2014-01-01

    The field of proton lung MRI is advancing on a variety of fronts. In the realm of functional imaging, it is now possible to use arterial spin labeling (ASL) and oxygen-enhanced imaging techniques to quantify regional perfusion and ventilation, respectively, in standard units of measure. By combining these techniques into a single scan, it is also possible to quantify the local ventilation-perfusion ratio, which is the most important determinant of gas-exchange efficiency in the lung. To demon...

  13. Assessment of baseline hemodynamic parameters within infarct progression areas in acute stroke patients using perfusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ritzenthaler, Thomas; Cho, Tae-Hee; Derex, Laurent; Nighoghossian, Norbert [Hospices Civils de Lyon, Cerebrovascular Unit, Hopital Neurologique Pierre Wertheimer, Bron (France); Claude Bernard Lyon 1 University, Creatis-LRMN, UMR 5520-Inserm 630, Lyon (France); Wiart, Marlene; Berthezene, Yves [Claude Bernard Lyon 1 University, Creatis-LRMN, UMR 5520-Inserm 630, Lyon (France); Berthiller, Julien [Hospices Civils de Lyon, Pole Information Medicale Evaluation Recherche, Lyon (France); Universite Lyon 1, Lyon (France); Oestergaard, Leif [University of Aarhus, Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus (Denmark); Hermier, Marc [Hospices Civils de Lyon, Neuroradiology Department, Hopital Neurologique Pierre Wertheimer, Lyon (France)

    2011-08-15

    The value of perfusion MRI for identifying the tissue at risk has been questioned. Our objective was to assess baseline perfusion-weighted imaging parameters within infarct progression areas. Patients with anterior circulation stroke without early reperfusion were included from a prospective MRI database. Sequential MRI examinations were performed on admission, 2-3 h (H2), 2-3 days (D2), and between 15 and 30 days after the initial MRI. Maps of baseline time-to-peak (TTP), mean transit time (MTT), cerebral blood volume (CBV), and cerebral blood flow (CBF) were calculated. Lesion extension areas were defined as pixels showing de novo lesions between each MRI and were generated by subtracting successive lesion masks: V{sub 0}, baseline diffusion-weighted imaging (DWI) lesion; V{sub 1}, lesion extension between baseline and H2 DWI; V{sub 2}, lesion extension from H2 to D2 DWI; and V{sub 3}, lesion extension from D2 DWI to final FLAIR. Repeated measures analysis was used to compare hemodynamic parameters within the baseline diffusion lesion and subsequent lesion extension areas. Thirty-two patients were included. Baseline perfusion parameters were significantly more impaired within the acute DWI lesion compared to lesion extension areas (TTP, p<0.0001; MTT, p<0.0001; CBF p<0.0001; CBV, p<0.0001). A significant decrease in MTT (p = 0.01) and TTP (p = 0.01) was found within successive lesion growth areas. A decreasing gradient of severity for TTP and MTT was observed within successive infarct growth areas. (orig.)

  14. Regional MRI Perfusion Measures Predict Motor/Executive Function in Patients with Clinically Isolated Syndrome

    Directory of Open Access Journals (Sweden)

    Efrosini Z. Papadaki

    2014-01-01

    Full Text Available Background. Patients with clinically isolated syndrome (CIS demonstrate brain hemodynamic changes and also suffer from difficulties in processing speed, memory, and executive functions. Objective. To explore whether brain hemodynamic disturbances in CIS patients correlate with executive functions. Methods. Thirty CIS patients and forty-three healthy subjects, matched for age, gender, education level, and FSIQ, were administered tests of visuomotor learning and set shifting ability. Cerebral blood volume (CBV, cerebral blood flow (CBF, and mean transit time (MTT values were estimated in normal-appearing white matter (NAWM and normal-appearing deep gray Matter (NADGM structures, using a perfusion MRI technique. Results. CIS patients showed significantly elevated reaction time (RT on both tasks, while their CBV and MTT values were globally increased, probably due to inflammatory vasodilation. Significantly, positive correlation coefficients were found between error rates on the inhibition condition of the visuomotor learning task and CBV values in occipital, periventricular NAWM and both thalami. On the set shifting condition of the respective task significant, positive associations were found between error rates and CBV values in the semioval center and periventricular NAWM bilaterally. Conclusion. Impaired executive function in CIS patients correlated positively with elevated regional CBV values thought to reflect inflammatory processes.

  15. MRI findings in multifetal pregnancies complicated by twin reversed arterial perfusion sequence (TRAP)

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Carolina V.A.; Kline-Fath, Beth M.; Linam, Leann E.; Calvo Garcia, Maria A.; Rubio, Eva I. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Lim, Foong-Yen [Cincinnati Children' s Hospital Medical Center, Division of Pediatric Surgery, Cincinnati, OH (United States)

    2011-06-15

    Twin reversed arterial perfusion sequence (TRAP) is a rare complication in multifetal monochorionic pregnancies in which a normal ''pump'' twin provides circulation to an abnormal acardiac co-twin, resulting in high-output cardiac dysfunction in the pump twin. To define fetal MRI findings of TRAP sequence. Fetal MR images were retrospectively reviewed in 35 pregnancies complicated by TRAP sequence. Abnormalities of the pump twin, acardiac twin, umbilical cord, placenta and amniotic fluid were reviewed. Acardiac twins were classified as: acephalus (51%), anceps (40%), amorphus (9%), acormus (0%). Common findings in acardiac twins include subcutaneous edema (77%), absent cardiac structures (86%), absent or abnormal thoracic cavity (100%), abnormal abdominal organs (100%), superior limbs absent (46%) or abnormal (51%), and inferior limbs present but abnormal (83%). There were pump twin findings of cardiac dysfunction in 43% and intracranial ischemic changes in 3%. Umbilical cord anomalies were present in 97%. Acardiac twins present with a predictable pattern of malformation with poorly developed superior structures, more normally formed inferior structures and absent or rudimentary heart. Although usually absent, abnormal heart structures can be seen and do not exclude TRAP sequence. Pump twins are commonly normal with exception of findings of cardiac dysfunction and possible brain ischemia. (orig.)

  16. MRI findings in multifetal pregnancies complicated by twin reversed arterial perfusion sequence (TRAP)

    International Nuclear Information System (INIS)

    Twin reversed arterial perfusion sequence (TRAP) is a rare complication in multifetal monochorionic pregnancies in which a normal ''pump'' twin provides circulation to an abnormal acardiac co-twin, resulting in high-output cardiac dysfunction in the pump twin. To define fetal MRI findings of TRAP sequence. Fetal MR images were retrospectively reviewed in 35 pregnancies complicated by TRAP sequence. Abnormalities of the pump twin, acardiac twin, umbilical cord, placenta and amniotic fluid were reviewed. Acardiac twins were classified as: acephalus (51%), anceps (40%), amorphus (9%), acormus (0%). Common findings in acardiac twins include subcutaneous edema (77%), absent cardiac structures (86%), absent or abnormal thoracic cavity (100%), abnormal abdominal organs (100%), superior limbs absent (46%) or abnormal (51%), and inferior limbs present but abnormal (83%). There were pump twin findings of cardiac dysfunction in 43% and intracranial ischemic changes in 3%. Umbilical cord anomalies were present in 97%. Acardiac twins present with a predictable pattern of malformation with poorly developed superior structures, more normally formed inferior structures and absent or rudimentary heart. Although usually absent, abnormal heart structures can be seen and do not exclude TRAP sequence. Pump twins are commonly normal with exception of findings of cardiac dysfunction and possible brain ischemia. (orig.)

  17. Crossed cerebellar diaschisis in acute isolated thalamic infarction detected by dynamic susceptibility contrast perfusion MRI.

    Directory of Open Access Journals (Sweden)

    Alex Förster

    Full Text Available PURPOSE: Crossed cerebellar diaschisis (CCD is a state of neural depression caused by loss of connections to injured neural structures remote from the cerebellum usually evaluated by positron emission tomography. Recently it has been shown that dynamic susceptibility contrast perfusion weighted MRI (PWI may also be feasible to detect the phenomenon. In this study we aimed to assess the frequency of CCD on PWI in patients with acute thalamic infarction. METHODS: From a MRI report database we identified patients with acute isolated thalamic infarction. Contralateral cerebellar hypoperfusion was identified by inspection of time to peak (TTP maps and evaluated quantitatively on TTP, mean transit time (MTT, cerebral blood flow and volume (CBF, CBV maps. A competing cerebellar pathology or an underlying vascular pathology were excluded. RESULTS: A total of 39 patients was included. Common symptoms were hemiparesis (53.8%, hemihypaesthesia (38.5%, dysarthria (30.8%, aphasia (17.9%, and ataxia (15.4%. In 9 patients (23.1% PWI showed hypoperfusion in the contralateral cerebellar hemisphere. All of these had lesions in the territory of the tuberothalamic, paramedian, or inferolateral arteries. Dysarthria was observed more frequently in patients with CCD (6/9 vs. 6/30; OR 8.00; 95%CI 1.54-41.64, p = 0.01. In patients with CCD, the median ischemic lesion volume on DWI (0.91 cm³, IQR 0.49-1.54 cm³ was larger compared to patients with unremarkable PWI (0.51 cm³, IQR 0.32-0.74, p = 0.05. The most pronounced changes were found in CBF (0.94±0.11 and MTT (1.06±0.13 signal ratios, followed by TTP (1.05±0.02. CONCLUSIONS: Multimodal MRI demonstrates CCD in about 20% of acute isolated thalamic infarction patients. Lesion size seems to be a relevant factor in its pathophysiology.

  18. 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

  19. 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.)

  20. Noninvasive stress testing of myocardial ischemia: comparison of GRE-MRI perfusion and wall motion analysis to 99mTc-MIBI-SPECT, relation to coronary angiography

    International Nuclear Information System (INIS)

    In the evaluation of ischemic heart disease only MR imaging seems to have the potential to assess myocardial perfusion, function, and coronary morphology on a single instrument. The aim of this study was to assess the feasibility of a stress test with dipyridamole (0.56 mg/kg) to analyze myocardial perfusion by Gd first-pass enhancement in ultrafast gradient-recalled-echo MRI (perf-MRI), and wall motion by cine gradient-recalled-echo MRI (Cine-MRI) in one imaging session. Twelve patients underwent complete rest and stress studies; satisfactory MR images were acquired in 10 patients. By 99mTc-MIBI-SPECT sensitivities to detect ischemic segments were 66.7 % with Perf-MRI, 80.0 % with WM-MRI and 86.7 % for Perf-WM-MRI (Perf-MRI vs Perf-WM-MRI; p = 0.03). Scar was equally detected with a sensitivity of 91.6 % with either MRI technique. Thus, Perf-Cine-MRI provides complementary information for the management of ischemic heart disease and has a higher sensitivity than Perf-MRI alone. (orig.). With 3 figs., 2 tabs

  1. Evaluation of dynamic contrast-enhanced T1-weighted perfusion MRI in the differentiation of tumor recurrence from radiation necrosis

    International Nuclear Information System (INIS)

    To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. The study was approved by the institutional review board and informed consent was obtained from all subjects. 19 patients were recruited following surgery and radiation therapy for glioma. Patients had contrast enhancing lesions, which during the standard MRI examination could not be exclusively determined as recurrence or radiation necrosis. DCE-MRI was used to measure cerebral blood volume (CBV), blood-brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used to determine whether lesions were regressing or progressing. Fourteen enhancing lesions could be classified as progressing (11) or regressing (three). An empirical threshold of 2.0 ml/100 g for CBV allowed detection of regressing lesions with a sensitivity of 100 % and specificity of 100 %. FDG-PET and DCE-MRI agreed in classification of tumor status in 13 out of the 16 cases where an FDG-PET classification was obtained. In two of the remaining three patients, MRI follow-up and histology was available and both indicated that the DCE-MRI answer was correct. CBV measurements using DCE-MRI may predict the status of contrast enhancing lesions and give results very similar to FDG-PET with regards to differentiation between tumor recurrence and radiation necrosis. (orig.)

  2. Evaluation of dynamic contrast-enhanced T1-weighted perfusion MRI in the differentiation of tumor recurrence from radiation necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Vibeke A. [Glostrup University Hospital, Department of Radiology, Glostrup (Denmark); Glostrup University Hospital, Department of Radiology, Copenhagen Oe (Denmark); Simonsen, Helle J.; Larsson, Henrik B.W. [Glostrup University Hospital, Functional Imaging Unit, Glostrup (Denmark); Glostrup University Hospital, Department of Clinical Physiology, Glostrup (Denmark); Law, Ian [Nuclear Medicine and PET, Department of Clinical Physiology, Copenhagen Oe (Denmark); Hansen, Adam E. [Glostrup University Hospital, Department of Radiology, Glostrup (Denmark); Glostrup University Hospital, Functional Imaging Unit, Glostrup (Denmark)

    2013-03-15

    To investigate if perfusion measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can be used to differentiate radiation necrosis from tumor recurrence in patients with high-grade glioma. The study was approved by the institutional review board and informed consent was obtained from all subjects. 19 patients were recruited following surgery and radiation therapy for glioma. Patients had contrast enhancing lesions, which during the standard MRI examination could not be exclusively determined as recurrence or radiation necrosis. DCE-MRI was used to measure cerebral blood volume (CBV), blood-brain barrier (BBB) permeability and cerebral blood flow (CBF). Subjects also underwent FDG-PET and lesions were classified as either metabolically active or inactive. Follow-up clinical MRI and lesion histology in case of additional tissue resection was used to determine whether lesions were regressing or progressing. Fourteen enhancing lesions could be classified as progressing (11) or regressing (three). An empirical threshold of 2.0 ml/100 g for CBV allowed detection of regressing lesions with a sensitivity of 100 % and specificity of 100 %. FDG-PET and DCE-MRI agreed in classification of tumor status in 13 out of the 16 cases where an FDG-PET classification was obtained. In two of the remaining three patients, MRI follow-up and histology was available and both indicated that the DCE-MRI answer was correct. CBV measurements using DCE-MRI may predict the status of contrast enhancing lesions and give results very similar to FDG-PET with regards to differentiation between tumor recurrence and radiation necrosis. (orig.)

  3. Quantification of myocardial perfusion using free-breathing MRI and prospective slice tracking

    DEFF Research Database (Denmark)

    Pedersen, Henrik; Kelle, Sebastian; Ringgaard, Steffen;

    2009-01-01

    . This study demonstrates the feasibility of patient-adapted 3D PST on a 3.0 Tesla MR system. Eight patients underwent free-breathing studies of myocardial perfusion, simultaneously collecting data with and without PST. On average, PST reduced residual in-plane motion by a factor of 2, compared...... to the noncorrected images, resulting in a fourfold improvement of perfusion measurements. In addition, a comparison of perfusion measurements performed with and without PST showed that through-plane motion can contaminate measurements of myocardial perfusion. However, the quality of the navigator echoes...

  4. DCE-MRI Perfusion and Permeability Parameters as predictors of tumor response to CCRT in Patients with locally advanced NSCLC

    Science.gov (United States)

    Tao, Xiuli; Wang, Lvhua; Hui, Zhouguang; Liu, Li; Ye, Feng; Song, Ying; Tang, Yu; Men, Yu; Lambrou, Tryphon; Su, Zihua; Xu, Xiao; Ouyang, Han; Wu, Ning

    2016-01-01

    In this prospective study, 36 patients with stage III non-small cell lung cancers (NSCLC), who underwent dynamic contrast-enhanced MRI (DCE-MRI) before concurrent chemo-radiotherapy (CCRT) were enrolled. Pharmacokinetic analysis was carried out after non-rigid motion registration. The perfusion parameters [including Blood Flow (BF), Blood Volume (BV), Mean Transit Time (MTT)] and permeability parameters [including endothelial transfer constant (Ktrans), reflux rate (Kep), fractional extravascular extracellular space volume (Ve), fractional plasma volume (Vp)] were calculated, and their relationship with tumor regression was evaluated. The value of these parameters on predicting responders were calculated by receiver operating characteristic (ROC) curve. Multivariate logistic regression analysis was conducted to find the independent variables. Tumor regression rate is negatively correlated with Ve and its standard variation Ve_SD and positively correlated with Ktrans and Kep. Significant differences between responders and non-responders existed in Ktrans, Kep, Ve, Ve_SD, MTT, BV_SD and MTT_SD (P < 0.05). ROC indicated that Ve < 0.24 gave the largest area under curve of 0.865 to predict responders. Multivariate logistic regression analysis also showed Ve was a significant predictor. Baseline perfusion and permeability parameters calculated from DCE-MRI were seen to be a viable tool for predicting the early treatment response after CCRT of NSCLC. PMID:27762331

  5. 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

  6. ASL? English? Which? Comparing Comprehension.

    Science.gov (United States)

    Eagney, Peggy

    1987-01-01

    Comparisons of 91 deaf children's (ages 5-15) understanding of 25 sentences presented in American Sign Language (ASL), simplified English, and standard English showed no significant differences in the children's ability to comprehend the three different forms. Findings do not support proposals to substitute ASL or simplified English for standard…

  7. Using Perfusion fMRI to Measure Continuous Changes in Neural Activity with Learning

    Science.gov (United States)

    Olson, Ingrid R.; Rao, Hengyi; Moore, Katherine Sledge; Wang, Jiongjiong; Detre, John A.; Aguirre, Geoffrey K.

    2006-01-01

    In this study, we examine the suitability of a relatively new imaging technique, "arterial spin labeled perfusion imaging," for the study of continuous, gradual changes in neural activity. Unlike BOLD imaging, the perfusion signal is stable over long time-scales, allowing for accurate assessment of continuous performance. In addition, perfusion…

  8. Reversible changes in echo planar perfusion- and diffusion-weighted MRI in status epilepticus

    Energy Technology Data Exchange (ETDEWEB)

    Flacke, S.; Keller, E.; Urbach, H. [Dept. of Radiology, Univ. of Bonn (Germany); Wuellner, U.; Hamzei, F. [Dept. of Neurology, Univ. of Bonn (Germany)

    2000-02-01

    Perfusion imaging (PI) demonstrated increased perfusion and diffusion-weighted imaging (DWI) showed high signal limited to the left temporoparietal cortex in a 68-year-old man with nonconvulsive status epilepticus. The EEG showed a slow delta-wave focus. The patient recovered and PI, DWI and EEG changes completely resolved. (orig.)

  9. Dopaminergic Therapy Modulates Cortical Perfusion in Parkinson Disease With and Without Dementia According to Arterial Spin Labeled Perfusion Magnetic Resonance Imaging.

    Science.gov (United States)

    Lin, Wei-Che; Chen, Pei-Chin; Huang, Yung-Cheng; Tsai, Nai-Wen; Chen, Hsiu-Ling; Wang, Hung-Chen; Lin, Tsu-Kung; Chou, Kun-Hsien; Chen, Meng-Hsiang; Chen, Yi-Wen; Lu, Cheng-Hsien

    2016-02-01

    Arterial spin labeling (ASL) magnetic resonance imaging analyses allow for the quantification of altered cerebral blood flow, and provide a novel means of examining the impact of dopaminergic treatments. The authors examined the cerebral perfusion differences among 17 Parkinson disease (PD) patients, 17 PD with dementia (PDD) patients, and 17 healthy controls and used ASL-MRI to assess the effects of dopaminergic therapies on perfusion in the patients. The authors demonstrated progressive widespread cortical hypoperfusion in PD and PDD and robust effects for the dopaminergic therapies. Specifically, dopaminergic medications further decreased frontal lobe and cerebellum perfusion in the PD and PDD groups, respectively. These patterns of hypoperfusion could be related to cognitive dysfunctions and disease severity. Furthermore, desensitization to dopaminergic therapies in terms of cortical perfusion was found as the disease progressed, supporting the concept that long-term therapies are associated with the therapeutic window narrowing. The highly sensitive pharmaceutical response of ASL allows clinicians and researchers to easily and effectively quantify the absolute perfusion status, which might prove helpful for therapeutic planning.

  10. Clinical impact of MRI perfusion disturbances and normal diffusion in acute stroke patients

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, D. [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)], E-mail: blondin@med.uni-duesseldorf.de; Seitz, R.J. [Department of Neurology, University Hospital Duesseldorf (Germany); Biomedical Research Centre, Heinrich-Heine-Universitaet Duesseldorf (Germany); Brain Imaging Centre, Research Centre Julich (Germany); Rusch, O.; Janssen, H.; Andersen, K.; Wittsack, H.-J.; Turowski, B. [Institute of Diagnostic Radiology, University Hospital Duesseldorf (Germany)

    2009-07-15

    Purpose: In acute ischemic stroke MR-imaging typically shows diffusion abnormalities surrounded by reduced perfusion signifying the so-called ischemic penumbra. Mismatch between diffusion and perfusion abnormalities gives indication for thrombolysis. But is there an indication for thrombolytic treatment, if there is no diffusion abnormality but pathologic perfusion combined with acute stroke symptoms?. Material and methods: MR-imaging of 1465 patients treated on our Stroke Unit between June 2004 and May 2007 retrospectively are analyzed. 6 patients met the inclusion criteria of severe neurological symptoms, large territorial perfusion disturbances, lack of diffusion abnormalities and complete neurological recovery after treatment. Results: In all six patients MTT measurements showed a significantly depressed perfusion in the symptomatic hemisphere (p < 0.02). Time-to-peak delay correlated with the mean transit time delay (0.949, p < 0.01). Indication for thrombolysis was based on perfusion abnormalities and clinical symptoms. Stroke symptoms could be reversed in all patients without any complication. Conclusion: Whereas diffusion imaging could not reveal any abnormality, perfusion analysis legitimated therapy with systemic thrombolysis in heavily affected patients. This work underlines the importance of multimodal MR imaging for guiding treatment decisions in acute stroke patients.

  11. Improved anatomic delineation of the antidepressant response to partial sleep deprivation in medial frontal cortex using perfusion-weighted functional MRI

    OpenAIRE

    Clark, Camellia P.; Brown, Gregory G; Frank, Lawrence; Thomas, Linda; Sutherland, Ashley N.; Gillin, J. Christian

    2006-01-01

    This study used functional magnetic resonance imaging (fMRI) to clarify the sites of brain activity associated with the antidepressant effects of sleep deprivation (SD). We hypothesized: 1) depressed responders’ baseline ventral anterior cingulate (AC) perfusion will be greater than that of nonresponders and controls; 2) following partial sleep deprivation (PSD), ventral AC perfusion will significantly decrease in responders only. Seventeen unmedicated outpatients with current major depressio...

  12. Perfusion MRI in hips with metal-on-metal and metal-on-polyethylene total hip arthroplasty

    Science.gov (United States)

    Anwander, H.; Cron, G. O.; Rakhra, K.

    2016-01-01

    Objectives Hips with metal-on-metal total hip arthroplasty (MoM THA) have a high rate of adverse local tissue reactions (ALTR), often associated with hypersensitivity reactions. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measures tissue perfusion with the parameter Ktrans (volume transfer constant of contrast agent). Our purpose was 1) to evaluate the feasibility of DCE-MRI in patients with THA and 2) to compare DCE-MRI in patients with MoM bearings with metal-on-polyethylene (MoP) bearings, hypothesising that the perfusion index Ktrans in hips with MoM THA is higher than in hips with MoP THA. Methods In this pilot study, 16 patients with primary THA were recruited (eight MoM, eight MoP). DCE-MRI of the hip was performed at 1.5 Tesla (T). For each patient, Ktrans was computed voxel-by-voxel in all tissue lateral to the bladder. The mean Ktrans for all voxels was then calculated. These values were compared with respect to implant type and gender, and further correlated with clinical parameters. Results There was no significant difference between the two bearing types with both genders combined. However, dividing patients by THA bearing and gender, women with MoM bearings had the highest Ktrans values, exceeding those of women with MoP bearings (0.067 min−1 versus 0.053 min−1; p-value stud. Bone Joint Res 2016;5:73–79. DOI: 10.1302/2046-3758.53.2000572. PMID:26935768

  13. Towards quantification of blood-flow changes during cognitive task activation using perfusion-based fMRI.

    Science.gov (United States)

    Mildner, Toralf; Zysset, Stefan; Trampel, Robert; Driesel, Wolfgang; Möller, Harald E

    2005-10-01

    Multi-slice perfusion-based functional magnetic resonance imaging (p-fMRI) is demonstrated with a color-word Stroop task as an established cognitive paradigm. Continuous arterial spin labeling (CASL) of the blood in the left common carotid artery was applied for all repetitions of the functional run in a quasi-continuous fashion, i.e., it was interrupted only during image acquisition. For comparison, blood oxygen level dependent (BOLD) contrast was detected using conventional gradient-recalled echo (GE) echo planar imaging (EPI). Positive activations in BOLD imaging appeared in p-fMRI as negative signal changes corresponding to an enhanced transport of inverted water spins into the region of interest, i.e., increased cerebral blood flow (CBF). Regional differences between the localization of activations and the sensitivity of p-fMRI and BOLD-fMRI were observed as, for example, in the inferior frontal sulcus and in the intraparietal sulcus. Quantification of CBF changes during cognitive task activation was performed on a multi-subject basis and yielded CBF increases of the order of 20-30%.

  14. Magnetic resonance perfusion imaging without contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz [University Hospital of Tuebingen, Section on Experimental Radiology, Tuebingen (Germany); Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D. [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2010-08-15

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  15. Estimation of intersubject variability of cerebral blood flow measurements using MRI and positron emission tomography

    DEFF Research Database (Denmark)

    Henriksen, Otto Mølby; Larsson, Henrik B W; Hansen, Adam E;

    2012-01-01

    PURPOSE: To investigate the within and between subject variability of quantitative cerebral blood flow (CBF) measurements in normal subjects using various MRI techniques and positron emission tomography (PET). MATERIALS AND METHODS: Repeated CBF measurements were performed in 17 healthy, young...... subjects using three different MRI techniques: arterial spin labeling (ASL), dynamic contrast enhanced T1 weighted perfusion MRI (DCE) and phase contrast mapping (PCM). All MRI measurements were performed within the same session. In 10 of the subjects repeated CBF measurements by (15) O labeled water PET...

  16. Comparison of dynamic susceptibility contrast-MRI perfusion quantification methods in the presence of delay and dispersion

    Science.gov (United States)

    Maan, Bianca; Simões, Rita Lopes; Meijer, Frederick J. A.; Klaas Jan Renema, W.; Slump, Cornelis H.

    2011-03-01

    The perfusion of the brain is essential to maintain brain function. Stroke is an example of a decrease in blood flow and reduced perfusion. During ischemic stroke the blood flow to tissue is hampered due to a clot inside a vessel. To investigate the recovery of stroke patients, follow up studies are necessary. MRI is the preferred imaging modality for follow up because of the absence of radiation dose concerns, contrary to CT. Dynamic Susceptibility Contrast (DSC) MRI is an imaging technique used for measuring perfusion of the brain, however, is not standard applied in the clinical routine due to lack of immediate patient benefit. Several post processing algorithms are described in the literature to obtain cerebral blood flow (CBF). The quantification of CBF relies on the deconvolution of a tracer concentration-time curve in an arterial and a tissue voxel. There are several methods to obtain this deconvolution based on singular-value decomposition (SVD). This contribution describes a comparison between the different approaches as currently there is no best practice for (all) clinical relevant situations. We investigate the influence of tracer delay, dispersion and recirculation on the performance of the methods. In the presence of negative delays, the truncated SVD approach overestimates the CBF. Block-circulant and reformulated SVD are delay-independent. Due to its delay dependent behavior, the truncated SVD approach performs worse in the presence of dispersion as well. However all SVD approaches are dependent on the amount of dispersion. Moreover, we observe that the optimal truncation parameter varies when recirculation is added to noisy data, suggesting that, in practice, these methods are not immune to tracer recirculation. Finally, applying the methods to clinical data resulted in a large variability of the CBF estimates. Block-circulant SVD will work in all situations and is the method with the highest potential.

  17. ¹⁸F-FDG PET metabolic parameters and MRI perfusion and diffusion parameters in hepatocellular carcinoma: a preliminary study.

    Directory of Open Access Journals (Sweden)

    Sung Jun Ahn

    Full Text Available OBJECTIVES: Glucose metabolism, perfusion, and water diffusion may have a relationship or affect each other in the same tumor. The understanding of their relationship could expand the knowledge of tumor characteristics and contribute to the field of oncologic imaging. The purpose of this study was to evaluate the relationships between metabolism, vasculature and cellularity of advanced hepatocellular carcinoma (HCC, using multimodality imaging such as ¹⁸F-FDG positron emission tomography (PET, dynamic contrast enhanced (DCE-MRI, and diffusion weighted imaging(DWI. MATERIALS AND METHODS: Twenty-one patients with advanced HCC underwent ¹⁸F-FDG PET, DCE-MRI, and DWI before treatment. Maximum standard uptake values (SUV(max from ¹⁸F-FDG-PET, variables of the volume transfer constant (K(trans from DCE-MRI and apparent diffusion coefficient (ADC from DWI were obtained for the tumor and their relationships were examined by Spearman's correlation analysis. The influence of portal vein thrombosis on SUV(max and variables of K(trans and ADC was evaluated by Mann-Whitney test. RESULTS: SUV(max showed significant negative correlation with K(trans(max (ρ = -0.622, p = 0.002. However, variables of ADC showed no relationship with variables of K(trans or SUV(max (p>0.05. Whether portal vein thrombosis was present or not did not influence the SUV max and variables of ADC and K(trans (p>0.05. CONCLUSION: In this study, SUV was shown to be correlated with K(trans in advanced HCCs; the higher the glucose metabolism a tumor had, the lower the perfusion it had, which might help in guiding target therapy.

  18. Limbic system perfusion in Alzheimer's disease measured by MRI-coregistered HMPAO SPET

    International Nuclear Information System (INIS)

    The goal of this study was to perform a systematic, semi-quantitative analysis of limbic perfusion in patients with Alzheimer's disease (AD) using coregistered single-photon emission tomography (SPET) images aligned to magnetic resonance (MR) images. Limbic perfusion in 40 patients with mild to moderate AD was compared with that of 17 age-, sex-, and education-matched normal controls (NC). HMPAO SPET scans and 3D T1-weighted MR images were acquired for each subject. Structures of the limbic system (i.e. hippocampus, amygdala, anterior thalamus, hypothalamus, mamillary bodies, basal forebrain, septal area and cingulate, orbitofrontal and parahippocampal cortices) were traced on the MR images and transferred to the coregistered SPET scans. Perfusion ratios for all limbic regions were calculated relative to cerebellar perfusion. General linear model multivariate analysis revealed that, overall, limbic structures showed significant hypoperfusion (F=7.802, P2=0.695) in AD patients compared with NC. Greatest differences (d≥0.8) were found in the hippocampus, as well as all areas of the cingulate cortex. Significant relative hypoperfusion was also apparent in the parahippocampal cortex, amygdala/entorhinal cortex, septal area and anterior thalamus, all of which showed medium to large effect sizes (d=0.6-0.8). No significant relative perfusion differences were detected in the basal forebrain, hypothalamus, mamillary bodies or orbitofrontal cortex. Logistic regression indicated that posterior cingulate cortex perfusion was able to discriminate AD patients from NC with 93% accuracy (95% sensitivity, 88% specificity). The current results suggest that most, but not all, limbic structures show significant relative hypoperfusion in AD. These findings validate previous post-mortem studies and could be useful in improving diagnostic accuracy, monitoring disease progression and evaluating potential treatment strategies in AD. (orig.)

  19. Impact of scar on water-perfusable tissue index in chronic ischemic heart disease - Evaluation with PET and contrast-enhanced MRI

    NARCIS (Netherlands)

    Knaapen, P.; Bonclarenko, O.; Beek, A.M.; Gotte, M.J.W.; Boellaard, R.; van der Weerdt, A.P.; de Visser, C.A.; van Rossum, A.C.; Lammertsma, A.A.; Visser, Folkert Willem

    2006-01-01

    Background: The water-perfusable tissue index (PTI) is assumed to differentiate viable myocardium from scar tissue, but histological comparisons in humans are lacking. The present study compares PTI with delayed contrast-enhanced magnetic resonance imaging (DCE-MRI), a validated marker of fibrotic t

  20. Correlation of perfusion MRI and 18F-FDG PET imaging biomarkers for monitoring regorafenib therapy in experimental colon carcinomas with immunohistochemical validation.

    Directory of Open Access Journals (Sweden)

    Ralf S Eschbach

    Full Text Available To investigate a multimodal, multiparametric perfusion MRI / 18F-fluoro-deoxyglucose-(18F-FDG-PET imaging protocol for monitoring regorafenib therapy effects on experimental colorectal adenocarcinomas in rats with immunohistochemical validation.Human colorectal adenocarcinoma xenografts (HT-29 were implanted subcutaneously in n = 17 (n = 10 therapy group; n = 7 control group female athymic nude rats (Hsd:RH-Foxn1rnu. Animals were imaged at baseline and after a one-week daily treatment protocol with regorafenib (10 mg/kg bodyweight using a multimodal, multiparametric perfusion MRI/18F-FDG-PET imaging protocol. In perfusion MRI, quantitative parameters of plasma flow (PF, mL/100 mL/min, plasma volume (PV, % and endothelial permeability-surface area product (PS, mL/100 mL/min were calculated. In 18F-FDG-PET, tumor-to-background-ratio (TTB was calculated. Perfusion MRI parameters were correlated with TTB and immunohistochemical assessments of tumor microvascular density (CD-31 and cell proliferation (Ki-67.Regorafenib significantly (p<0.01 suppressed PF (81.1±7.5 to 50.6±16.0 mL/100mL/min, PV (12.1±3.6 to 7.5±1.6% and PS (13.6±3.2 to 7.9±2.3 mL/100mL/min as well as TTB (3.4±0.6 to 1.9±1.1 between baseline and day 7. Immunohistochemistry revealed significantly (p<0.03 lower tumor microvascular density (CD-31, 7.0±2.4 vs. 16.1±5.9 and tumor cell proliferation (Ki-67, 434.0 ± 62.9 vs. 663.0 ± 98.3 in the therapy group. Perfusion MRI parameters ΔPF, ΔPV and ΔPS showed strong and significant (r = 0.67-0.78; p<0.01 correlations to the PET parameter ΔTTB and significant correlations (r = 0.57-0.67; p<0.03 to immunohistochemical Ki-67 as well as to CD-31-stainings (r = 0.49-0.55; p<0.05.A multimodal, multiparametric perfusion MRI/PET imaging protocol allowed for non-invasive monitoring of regorafenib therapy effects on experimental colorectal adenocarcinomas in vivo with significant correlations between perfusion MRI parameters and 18F

  1. Automated vs manual delineations of regions of interest- a comparison in commercially available perfusion MRI software

    Directory of Open Access Journals (Sweden)

    Galinovic Ivana

    2012-07-01

    Full Text Available Abstract Background In perfusion magnetic resonance imaging a manual approach to delineation of regions of interest is, due to rater bias and time intensive operator input, clinically less favorable than an automated approach would be. The goal of our study was to compare the performances of these approaches. Methods Using Stroketool, PMA and Perfscape/Neuroscape perfusion maps of cerebral blood flow, mean transit time and Tmax were created for 145 patients with acute ischemic stroke. Volumes of hypoperfused tissue were calculated using both a manual and an automated protocol, and the results compared between methods. Results The median difference between the automatically and manually derived volumes was up to 210 ml in Perfscape/Neuroscape, 123 ml in PMA and 135 ml in Stroketool. Correlation coefficients between perfusion volumes and radiological and clinical outcome were much lower for the automatic volumes than for the manually derived ones. Conclusions The agreement of the two methods was very poor, with the automated use producing falsely exaggerated volumes of hypoperfused tissue. Software improvements are necessary to enable highly automated protocols to credibly assess perfusion deficits.

  2. A neuroradiologist's guide to arterial spin labeling MRI in clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Grade, M. [Queen Square, UCL Institute of Neurology, London (United Kingdom); Stanford School of Medicine, Stanford, CA (United States); Hernandez Tamames, J.A. [Rey Juan Carlos University, Medical Image Analysis and Biometry Laboratory, Madrid (Spain); Erasmus MC - University Medical Centre Rotterdam, Department of Radiology, PO Box 2040, Rotterdam (Netherlands); Pizzini, F.B. [Queen Square, UCL Institute of Neurology, London (United Kingdom); Verona University Hospital, Neuroradiology, Department of Diagnostics and Pathology, Verona (Italy); Achten, E. [Ghent University Hospital, Neuroradiology, Department of Radiology, Ghent (Belgium); Golay, X. [Queen Square, UCL Institute of Neurology, London (United Kingdom); Smits, M. [Erasmus MC - University Medical Centre Rotterdam, Department of Radiology, PO Box 2040, Rotterdam (Netherlands)

    2015-12-15

    Arterial spin labeling (ASL) is a non-invasive MRI technique to measure cerebral blood flow (CBF). This review provides a practical guide and overview of the clinical applications of ASL of the brain, as well its potential pitfalls. The technical and physiological background is also addressed. At present, main areas of interest are cerebrovascular disease, dementia and neuro-oncology. In cerebrovascular disease, ASL is of particular interest owing to its quantitative nature and its capability to determine cerebral arterial territories. In acute stroke, the source of the collateral blood supply in the penumbra may be visualised. In chronic cerebrovascular disease, the extent and severity of compromised cerebral perfusion can be visualised, which may be used to guide therapeutic or preventative intervention. ASL has potential for the detection and follow-up of arteriovenous malformations. In the workup of dementia patients, ASL is proposed as a diagnostic alternative to PET. It can easily be added to the routinely performed structural MRI examination. In patients with established Alzheimer's disease and frontotemporal dementia, hypoperfusion patterns are seen that are similar to hypometabolism patterns seen with PET. Studies on ASL in brain tumour imaging indicate a high correlation between areas of increased CBF as measured with ASL and increased cerebral blood volume as measured with dynamic susceptibility contrast-enhanced perfusion imaging. Major advantages of ASL for brain tumour imaging are the fact that CBF measurements are not influenced by breakdown of the blood-brain barrier, as well as its quantitative nature, facilitating multicentre and longitudinal studies. (orig.)

  3. MRI and MRA of kidney transplants - evaluation of vessels and perfusion; MRT und MRA von Nierentransplantaten - Gefaess- und Perfusionsbeurteilung

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, W.; Pfammatter, T.; Krestin, G.P.; Debatin, J.F. [Universitaetsspital Zuerich (Switzerland). Inst. fuer Diagnostische Radiologie

    1998-09-01

    Purpose: To document the value of fast contrast enhanced-sequences in the assessment of the vascular supply and parenchymal perfusion in renal transplants. Patients: 18 recipients of a renal transplant were examined with a 1.5-Tesla-MR-system. The protocol included fast contrast enhanced 3D MR angiography and coronal 2D GRE sequences. The transplant artery and vein were assessed as well as regional parenchymal perfusion. Results: 3D MRA detected three transplant artery stenoses and one occlusion. In addition, two renal vein thromboses and one compression were identified. Perfusion deficits were documented in 8 renal transplants: Renal infarction (n=4), cortical necrosis (n=2), acute tubular necrosis (n=1) and venous ischemia (n=1). Fluid collections were documented as well as dilatation of the collecting system and abnormalities of the surrounding tissues. Conclusion: Contrast enhanced MRI and MRA permit a comprehensive assessment of renal transplants without inducing nephrotoxicity. (orig.) [Deutsch] Ziel: Retrospektive Studie zur Erfassung der diagnostischen Aussagekraft schneller KM-verstaerkter MR-Sequenzen bei der Darstellung der Gefaess- und Perfusionsverhaeltnisse in Transplantatnieren. Patienten: 18 Transplantatnierenempfaenger wurden in einem 1,5-Tesla-MR-System untersucht. Das Untersuchungsprotokoll umfasste eine schnelle KM-verstaerkte 3D-MR-Angiographie sowie koronare 2D-GRE-Sequenzen. Analysiert wurden die Transplantatarterie(n), die Transplantatvene(n), die regionale Parenchymperfusion sowie die Organ- und Umgebungsmorphologie. Ergebnisse: Mit der 3D-MRA kamen arterielle Stenosen (n=3), ein arterieller Verschluss, Venenthrombosen (n=2) und eine Venenkompression zur Darstellung. Eingeschraenkte Parenchymperfusion wurde in 8 Transplantaten (renale Infarkte (n=4), kortikale Nekrose (n=2), akute Tubulusnekrose (n=1), venoese Ischaemie (n=1)) nachgewiesen. Fluessigkeitsansammlungen wurden ebenso wie Abflussstoerungen des Nierenbeckenkelchsystems und

  4. Comparative study of DSC-PWI and 3D-ASL in ischemic stroke patients.

    Science.gov (United States)

    Zhang, Shui-xia; Yao, Yi-hao; Zhang, Shun; Zhu, Wen-jie; Tang, Xiang-yu; Qin, Yuan-yuan; Zhao, Ling-yun; Liu, Cheng-xia; Zhu, Wen-zhen

    2015-12-01

    The purpose of this study was to quantitatively analyze the relationship between three dimensional arterial spin labeling (3D-ASL) and dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI) in ischemic stroke patients. Thirty patients with ischemic stroke were included in this study. All subjects underwent routine magnetic resonance imaging scanning, diffusion weighted imaging (DWI), magnetic resonance angiography (MRA), 3D-ASL and DSC-PWI on a 3.0T MR scanner. Regions of interest (ROIs) were drawn on the cerebral blood flow (CBF) maps (derived from ASL) and multi-parametric DSC perfusion maps, and then, the absolute and relative values of ASL-CBF, DSC-derived CBF, and DSC-derived mean transit time (MTT) were calculated. The relationships between ASL and DSC parameters were analyzed using Pearson's correlation analysis. Receiver operative characteristic (ROC) curves were performed to define the thresholds of relative value of ASL-CBF (rASL) that could best predict DSC-CBF reduction and MTT prolongation. Relative ASL better correlated with CBF and MTT in the anterior circulation with the Pearson correlation coefficients (R) values being 0.611 (P1.0 were 75.7%, 89.2% and 87.8% respectively. ASL-CBF map has better linear correlations with DSC-derived parameters (DSC-CBF and MTT) in anterior circulation in ischemic stroke patients. Additionally, when rASL is lower than 0.585, it could predict DSC-CBF decrease with moderate accuracy. If rASL values range from 0.585 to 0.952, we just speculate the prolonged MTT.

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

    Science.gov (United States)

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2007-01-01

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

  7. Simultaneous perfusion and permeability measurements using combined spin- and gradient-echo MRI.

    Science.gov (United States)

    Schmiedeskamp, Heiko; Andre, Jalal B; Straka, Matus; Christen, Thomas; Nagpal, Seema; Recht, Lawrence; Thomas, Reena P; Zaharchuk, Greg; Bammer, Roland

    2013-05-01

    The purpose of this study was to estimate magnetic resonance imaging-based brain perfusion parameters from combined multiecho spin-echo and gradient-echo acquisitions, to correct them for T₁₋, T₂₋, and T₂₋*-related contrast agent (CA) extravasation effects, and to simultaneously determine vascular permeability. Perfusion data were acquired using a combined multiecho spin- and gradient-echo (SAGE) echo-planar imaging sequence, which was corrected for CA extravasation effects using pharmacokinetic modeling. The presented method was validated in simulations and brain tumor patients, and compared with uncorrected single-echo and multiecho data. In the presence of CA extravasation, uncorrected single-echo data resulted in underestimated CA concentrations, leading to underestimated single-echo cerebral blood volume (CBV) and mean transit time (MTT). In contrast, uncorrected multiecho data resulted in overestimations of CA concentrations, CBV, and MTT. The correction of CA extravasation effects resulted in CBV and MTT estimates that were more consistent with the underlying tissue characteristics. Spin-echo perfusion data showed reduced large-vessel blooming effects, facilitating better distinction between increased CBV due to active tumor progression and elevated CBV due to the presence of cortical vessels in tumor proximity. Furthermore, extracted permeability parameters were in good agreement with elevated T1-weighted postcontrast signal values.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

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

  9. Hemodynamic significance of coronary stenosis by vessel attenuation measurement on CT compared with adenosine perfusion MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, Martijn A.M. den; Pelgrim, Gert Jan; Pundziute, Gabija; Heuvel, Edwin R. van den; Oudkerk, Matthijs; Vliegenthart, Rozemarijn, E-mail: r.vliegenthart@umcg.nl

    2015-01-15

    Highlights: • The majority of anatomical coronary stenoses do not cause myocardial ischemia. • cCTA-derived CCO decrease expresses luminal density gradient across stenosis. • CCO decrease differentiates between anatomical stenoses with and without associated myocardial ischemia. • CCO decrease assessment can exclude the majority of stenoses without hemodynamic significance. - Abstract: Purpose: We assessed the association between corrected contrast opacification (CCO) based on coronary computed tomography angiography (cCTA) and inducible ischemia by adenosine perfusion magnetic resonance imaging (APMR). Methods: Sixty cardiac asymptomatic patients with extra-cardiac arterial disease (mean age 64.4 ± 7.7 years; 78% male) underwent cCTA and APMR. Luminal CT attenuation values (Hounsfield Units) were measured in coronary arteries from proximal to distal, with additional measurements across sites with >50% lumen stenosis. CCO was calculated by dividing coronary CT attenuation by descending aorta CT attenuation. A reversible perfusion defect on APMR was considered as myocardial ischemia. Results: In total, 169 coronary stenoses were found. Seven patients had 8 perfusion defects on APMR, with 11 stenoses in corresponding vessels. CCO decrease across stenoses with hemodynamic significance was 0.144 ± 0.112 compared to 0.047 ± 0.104 across stenoses without hemodynamic significance (P = 0.003). CCO decrease in lesions with and without anatomical stenosis was similar (0.054 ± 0.116 versus 0.052 ± 0.101; P = 0.89). Using 0.20 as preliminary CCO decrease cut-off, hemodynamic significance would be excluded in 82.9% of anatomical stenoses. Conclusions: CCO decrease across coronary stenosis is associated with myocardial ischemia on APMR. CCO based on common cCTA data is a novel method to assess hemodynamic significance of anatomical stenosis.

  10. Comparison of the PET with fluoro-ethyl-tyrosine to perfusion MRI and T1 injected in the exploration of glial tumors: a pilot study

    International Nuclear Information System (INIS)

    Molecular imaging could be used in complement of MRI injected in the initial result of cerebral tumors. This study has for aim to compare the performances of the positron computed tomography with fluoro-ethyl-tyrosine (F.E.T.) with the T1 sequences with gadolinium injection and perfusion MRI in the staging of glial tumors. In spite of the low strength of the series, the cerebral PET shows a good performance in the staging of glial tumors, without being superior to MRI. however, the results seem interesting in view of possible merging to allow targeting at the best, the biopsies, especially for the injuries classified high grade for MRI without contrast after gadolinium injection. (N.C.)

  11. Perfusion and vascular permeability: basic concepts and measurement in DCE-CT and DCE-MRI.

    Science.gov (United States)

    Cuenod, C A; Balvay, D

    2013-12-01

    The microvascular network formed by the capillaries supplies the tissues and permits their function. It provides a considerable surface area for exchanges between blood and tissues. All pathological conditions cause changes in the microcirculation. These changes can be used as imaging biomarkers for the diagnosis of lesions and optimisation of treatment. Among the many imaging techniques developed to study the microcirculation, the analysis of the tissue kinetics of intravenously injected contrast agents is the most widely used, either as positive enhancement for CT, T1-weighted MRI and ultrasound - dynamic contrast-enhanced-imaging (DCE-imaging) - or negative enhancement in T2*-weighted brain MRI - dynamic susceptibility contrast-MRI (DSC-MRI) -. Acquisition involves an injection of contrast agent during the acquisition of a dynamic series of images on a zone of interest. These kinetics may be analyzed visually, to define qualitative criteria, or with software using mathematical modelling, to extract quantitative physiological parameters. The results depend on the acquisition conditions (type of imaging device, imaging mode, frequency and total duration of acquisition), the type of contrast agent, the data pre-processing (motion correction, conversion of the signal into concentration) and the data analysis method. Because of these multiple choices it is necessary to understand the physiological processes involved and understand the advantages and limits of each strategy.

  12. Perfusion MRI abnormalities in the absence of diffusion changes in a case of moyamoya-like syndrome in neurofibromatosis type 1

    Energy Technology Data Exchange (ETDEWEB)

    El-Koussy, Marwan; Kiefer, Claus; Schroth, Gerhard [Department of Neuroradiology, University of Bern, Inselspital, Freiburgstrasse 4, 3010 Bern (Switzerland); Loevblad, Karl-Olof [Department of Neuroradiology, University of Bern, Inselspital, Freiburgstrasse 4, 3010 Bern (Switzerland); Neuroradiology, Service de Radiodiagnostic, Hopital Cantonal Universitaire HUG, 24 rue Micheli-du-Crest, 1211 Geneva 11 (Switzerland); Steinlin, Maja [Department of Neuropediatrics, University of Bern, Inselspital, Freiburgstrasse 4, 3010 Bern (Switzerland)

    2002-11-01

    We report on a 12-year-old boy with neurofibromatosis type 1 who suffered a transient ischemic attack. Angiography revealed occlusion of intracranial arteries, moyamoya vessels and leptomeningeal collaterals. The conventional T2-weighted and the diffusion-weighted MRI images demonstrated no pathology. Dynamic first-pass postgadolinium T2* perfusion-weighted MRI depicted altered hemodynamics in the vascular territory of the left middle cerebral artery, which defined this region as ischemic tissue at risk. The patient suffered a repeat transient ischemic attack5 days later. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Sureyya Burcu Gorkem

    2016-01-01

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

  14. Brain perfusion in dementia with Lewy bodies and Alzheimer’s disease: an arterial spin labeling MRI study on prodromal and mild dementia stages

    OpenAIRE

    Roquet, Daniel; Sourty, Marion; Botzung, Anne; Armspach, Jean-Paul; Blanc, Frédéric

    2016-01-01

    Background We aimed to describe specific changes in brain perfusion in patients with dementia with Lewy bodies (DLB) at both the prodromal (also called mild cognitive impairment) and mild dementia stages, relative to patients with Alzheimer’s disease (AD) and controls. Methods Altogether, 96 participants in five groups (prodromal DLB, prodromal AD, DLB with mild dementia, AD with mild dementia, and healthy elderly controls) took part in an arterial spin labeling MRI study. Three analyses were...

  15. Assessment of predictive indices for glioblastomas radiation therapy: comparison of perfusion MRI and spectrometric imagery by magnetic resonance; Evaluation d'indices predictifs pour la radiotherapie des glioblastomes: comparaison de l'IRM de perfusion et de l'imagerie de spectrometrie par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lemoine, J.M.; Laprie, A.; Moyal Cohen-Jonathan, E.; Ken, S. [Departement de radiotherapie, institut Claudius-Regaud, 31 - Toulouse (France); Lemoine, J.M.; Laprie, A.; Franceries, X.; Lotterie, J.A.; Celsis, P.; Lubrano, V.; Berry, I.; Ken, S. [Inserm, UMR 825, imagerie cerebrale et handicaps neurologiques, 31 - Toulouse (France); Lemoine, J.M.; Franceries, X. [Universite Paul-Sabatier, 31 - Toulouse (France); Lotterie, J.A.; Berry, I. [Departement de biophysique, CHU Rangueil, 31 - Toulouse (France); Lubrano, V. [Departement de neurochirurgie, CHU Rangueil, 31 - Toulouse (France)

    2010-10-15

    The authors report the comparison of several imagery modalities: anatomic imagery (T1-weighted MRI after gadolinium injection and T2-weighted MRI), metabolic imagery (spectrometric imagery by magnetic resonance) and functional imagery (perfusion MRI). This comparison has been performed within the frame of a prospective clinic test associating a radiosensitizer concomitant with a radiation therapy of glioblastomas. It appears that the integration of data of spectrometric imagery by magnetic resonance and of perfusion MRI is a promising method to overcome the resistance of glioblastomas. Short communication

  16. 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

  17. Morphological and functional MRI, MRS, perfusion and diffusion changes after radiosurgery of brain metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Tae Wook [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: tw227.kang@samsung.com; Kim, Sung Tae [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: st7.kim@hotmail.com; Byun, Hong Sik [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: hongsik5474.byun@samsung.com; Jeon, Pyoung [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: pyoung.jeon@samsung.com; Kim, Keonha [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: somatom.kim@samsung.com; Kim, Hyungjin [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: hyungjin1219.kim@samsung.com; Lee, Jung II [Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710 (Korea, Republic of)], E-mail: jilee.lee@samsung.com

    2009-12-15

    Radiosurgery is a noninvasive procedure where spatially accurate and highly conformal doses of radiation are targeted at brain lesions with an ablative intent. Recently, radiosurgery has been established as an effective technique for local treatment of brain metastasis. After radiosurgery, magnetic resonance (MR) imaging plays an important role in the assessment of the therapeutic response and of any complications. The therapeutic approach depends on the imaging findings obtained after radiosurgery, which have a role in the decision making to perform additional invasive modalities (repeat resection, biopsy) to obtain a definite diagnosis and to improve the survival of patients. Conventional MR imaging findings are mainly based on morphological alterations of tumors. However, there are variable imaging findings of radiation-induced changes including radiation necrosis in the brain. Radiologists are sometimes confused by radiation-induced injuries, including radiation necrosis, that are seen on conventional MR imaging. The pattern of abnormal enhancement on follow-up conventional MR imaging closely mimics that of a recurrent brain metastasis. So, classifying newly developed abnormal enhancing lesions in follow-up of treated brain metastasis with correct diagnosis is one of the key goals in neuro-oncologic imaging. To overcome limitations of the use of morphology-based conventional MR imaging, several physiological-based functional MR imaging methods have been used, namely diffusion-weighted imaging, perfusion MR imaging, and proton MR spectroscopy, for the detection of hemodynamic, metabolic, and cellular alterations. These imaging modalities provide additional information to allow clinicians to make proper decisions regarding patient treatment.

  18. 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.)

  19. Current concepts on magnetic resonance imaging (MRI) perfusion-diffusion assessment in acute ischaemic stroke: a review & an update for the clinicians.

    Science.gov (United States)

    Roldan-Valadez, Ernesto; Lopez-Mejia, Mariana

    2014-12-01

    Recently, several medical societies published joint statements about imaging recommendations for acute stroke and transient ischaemic attack patients. In following with these published guidelines, we considered it appropriate to present a brief, practical and updated review of the most relevant concepts on the MRI assessment of acute stroke. Basic principles of the clinical interpretation of diffusion, perfusion, and MRI angiography (as part of a global MRI protocol) are discussed with accompanying images for each sequence. Brief comments on incidence and differential diagnosis are also included, together with limitations of the techniques and levels of evidence. The purpose of this article is to present knowledge that can be applied in day-to-day clinical practice in specialized stroke units or emergency rooms to attend patients with acute ischaemic stroke or transient ischaemic attack according to international standards. PMID:25758570

  20. Current concepts on magnetic resonance imaging (MRI perfusion-diffusion assessment in acute ischaemic stroke: a review & an update for the clinicians

    Directory of Open Access Journals (Sweden)

    Ernesto Roldan-Valadez

    2014-01-01

    Full Text Available Recently, several medical societies published joint statements about imaging recommendations for acute stroke and transient ischaemic attack patients. In following with these published guidelines, we considered it appropriate to present a brief, practical and updated review of the most relevant concepts on the MRI assessment of acute stroke. Basic principles of the clinical interpretation of diffusion, perfusion, and MRI angiography (as part of a global MRI protocol are discussed with accompanying images for each sequence. Brief comments on incidence and differential diagnosis are also included, together with limitations of the techniques and levels of evidence. The purpose of this article is to present knowledge that can be applied in day-to-day clinical practice in specialized stroke units or emergency rooms to attend patients with acute ischaemic stroke or transient ischaemic attack according to international standards.

  1. Functional lung MRI in chronic obstructive pulmonary disease: comparison of T1 mapping, oxygen-enhanced T1 mapping and dynamic contrast enhanced perfusion.

    Directory of Open Access Journals (Sweden)

    Bertram J Jobst

    Full Text Available Monitoring of regional lung function in interventional COPD trials requires alternative endpoints beyond global parameters such as FEV1. T1 relaxation times of the lung might allow to draw conclusions on tissue composition, blood volume and oxygen fraction. The aim of this study was to evaluate the potential value of lung Magnetic resonance imaging (MRI with native and oxygen-enhanced T1 mapping for the assessment of COPD patients in comparison with contrast enhanced perfusion MRI.20 COPD patients (GOLD I-IV underwent a coronal 2-dimensional inversion recovery snapshot flash sequence (8 slices/lung at room air and during inhalation of pure oxygen, as well as dynamic contrast-enhanced first-pass perfusion imaging. Regional distribution of T1 at room air (T1, oxygen-induced T1 shortening (ΔT1 and peak enhancement were rated by 2 chest radiologists in consensus using a semi-quantitative 3-point scale in a zone-based approach.Abnormal T1 and ΔT1 were highly prevalent in the patient cohort. T1 and ΔT1 correlated positively with perfusion abnormalities (r = 0.81 and r = 0.80; p&0.001, and with each other (r = 0.80; p<0.001. In GOLD stages I and II ΔT1 was normal in 16/29 lung zones with mildly abnormal perfusion (15/16 with abnormal T1. The extent of T1 (r = 0.45; p<0.05, ΔT1 (r = 0.52; p<0.05 and perfusion abnormalities (r = 0.52; p<0.05 showed a moderate correlation with GOLD stage.Native and oxygen-enhanced T1 mapping correlated with lung perfusion deficits and severity of COPD. Under the assumption that T1 at room air correlates with the regional pulmonary blood pool and that oxygen-enhanced T1 reflects lung ventilation, both techniques in combination are principally suitable to characterize ventilation-perfusion imbalance. This appears valuable for the assessment of regional lung characteristics in COPD trials without administration of i.v. contrast.

  2. Progress of MR perfusion weighted imaging in glioma%MR灌注成像在脑胶质瘤中的研究进展

    Institute of Scientific and Technical Information of China (English)

    赵灿灿; 翟建

    2015-01-01

    MR灌注成像主要通过测量血流动力学参数来反映组织血流灌注及微血管渗透情况。根据其成像原理不同分为动态磁敏感对比增强MRI(DSC-MRI)、动态对比增强MRI(DCE-MRI)和动脉自旋标记(ASL)灌注成像。这些方法各有优缺点,就MR灌注成像的基本原理及其在脑胶质瘤中的研究进展进行综述。%MR perfusion weighted imaging could evaluate tissue blood perfusion and microvascular permeability by measuring different parameters. According to the different imaging principles, the techniques could be classified into dynamic susceptibility contrast MRI (DSC-MRI), dynamic contrast-enhanced MRI (DCE-MRI), and arterial spin labeling perfusion weighted imaging (ASL-PWI). Each technique has its advantages and disadvantages. In this review we summarized the basic principles and applications of PWI in glioma.

  3. Comparison of quantitative dynamic susceptibility-contrast MRI perfusion estimates obtained using different contrast-agent administration schemes at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Wirestam, Ronnie, E-mail: Ronnie.Wirestam@med.lu.s [Department of Medical Radiation Physics, Lund University, University Hospital, SE-22185 Lund (Sweden); Thilmann, Oliver; Knutsson, Linda [Department of Medical Radiation Physics, Lund University, University Hospital, SE-22185 Lund (Sweden); Bjoerkman-Burtscher, Isabella M. [Department of Diagnostic Radiology, Lund University, University Hospital, SE-22185 Lund (Sweden); Larsson, Elna-Marie [Division of Radiology, Department of Oncology, Radiology and Clinical Immunology, Uppsala University, Akademiska sjukhuset, SE-75185 Uppsala (Sweden); Stahlberg, Freddy [Department of Medical Radiation Physics, Lund University, University Hospital, SE-22185 Lund (Sweden); Department of Diagnostic Radiology, Lund University, University Hospital, SE-22185 Lund (Sweden)

    2010-07-15

    Absolute cerebral perfusion parameters were obtained by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) carried out using different contrast-agent administration protocols. Sixteen healthy volunteers underwent three separate DSC-MRI examinations each, receiving single-dose (0.1 mmol/kg b.w.) gadobutrol, double-dose gadobutrol and single-dose gadobenate-dimeglumine on different occasions. DSC-MRI was performed using single-shot gradient-echo echo-planar imaging at 3 T. The arterial input functions (AIFs) were averages (4-9 pixels) of arterial curves from middle cerebral artery branches, automatically identified according to standard criteria. Absolute estimates of cerebral blood volume (CBV), cerebral blood flow (CBF) and mean transit time (MTT) were calculated without corrections for non-linear contrast-agent (CA) response in blood or for different T2* relaxivities in tissue and artery. Perfusion estimates obtained using single and double dose of gadobutrol correlated moderately well, while the relationship between estimates obtained using gadobutrol and gadobenate-dimeglumine showed generally lower correlation. The observed degree of CBV and CBF overestimation, compared with literature values, was most likely caused by different T2* relaxivities in blood and tissue in combination with partial-volume effects. The present results showed increased absolute values of CBV and CBF at higher dose, not predicted by the assumption of a quadratic response to contrast-agent concentration in blood. This indicates that the signal components of measured AIFs were not purely of arterial origin and that arterial signal components were more effectively extinguished at higher CA dose. This study also indicates that it may not be completely straightforward to compare absolute perfusion estimates obtained with different CA administration routines.

  4. Regional heterogeneity changes in DCE-MRI as response to isolated limb perfusion in experimental soft-tissue sarcomas.

    NARCIS (Netherlands)

    Alić, L.; Vliet, M. van; Wielopolski, P.A.; Hagen, T.L.M. ten; Dijke, C.F. van; Niessen, W.J.; Veenland, J.F.

    2013-01-01

    Experimental evidence supports an association between heterogeneity in tumor perfusion and response to chemotherapy/radiotherapy, disease progression and malignancy. Therefore, changes in tumor perfusion may be used to assess early effects of tumor treatment. However, evaluating changes in tumor per

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Objectives: Deficient microvascular blood flow control is thought to cause tumor hypoxia and increase resistance to therapy. In glioma patients, we tested whether perfusion-weighted MRI (PWI) based indices of microvascular flow control provide more information on tumor grade and patient outcome...... of microvascular flow control and the extent to which oxygen can be extracted by tumor tissue. The ability of these parameters and CBV to differentiate tumor grade were assessed by receiver operating characteristic curves and logistic regression. Their ability to predict time to progression and overall survival...... identified best by CTH (AUC=0.763; pflow control in tumor growth by demonstrating...

  6. 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

  7. Cerebral Blood Flow Alterations as Assessed by 3D ASL in Cognitive Impairment in Patients with Subcortical Vascular Cognitive Impairment: A Marker for Disease Severity.

    Science.gov (United States)

    Sun, Yawen; Cao, Wenwei; Ding, Weina; Wang, Yao; Han, Xu; Zhou, Yan; Xu, Qun; Zhang, Yong; Xu, Jianrong

    2016-01-01

    Abnormal reductions in cortical cerebral blood flow (CBF) have been identified in subcortical vascular cognitive impairment (SVCI). However, little is known about the pattern of CBF reduction in relation with the degree of cognitive impairment. CBF measured with three-dimensional (3D) Arterial Spin Labeling (ASL) perfusion magnetic resonance imaging (MRI) helps detect functional changes in subjects with SVCI. We aimed to compare CBF maps in subcortical ischemic vascular disease (SIVD) subjects with and without cognitive impairment and to detect the relationship of the regions of CBF reduction in the brain with the degree of cognitive impairment according to the z-score. A total of 53 subjects with SVCI and 23 matched SIVD subjects without cognitive impairment (controls), underwent a whole-brain 3D ASL MRI in the resting state. Regional CBF (rCBF) was compared voxel wise by using an analysis of variance design in a statistical parametric mapping program, with patient age and sex as covariates. Correlations were calculated between the rCBF value in the whole brain and the z-score in the 53 subjects with SVCI. Compared with the control subjects, SVCI group demonstrated diffuse decreased CBF in the brain. Significant positive correlations were determined in the rCBF values in the left hippocampus, left superior temporal pole gyrus, right superior frontal orbital lobe, right medial frontal orbital lobe, right middle temporal lobe, left thalamus and right insula with the z-scores in SVCI group. The noninvasively quantified resting CBF demonstrated altered CBF distributions in the SVCI brain. The deficit brain perfusions in the temporal and frontal lobe, hippocampus, thalamus and insula was related to the degree of cognitive impairment. Its relationship to cognition indicates the clinical relevance of this functional marker. Thus, our results provide further evidence for the mechanisms underlying the cognitive deficit in patients with SVCI. PMID:27630562

  8. WE-G-18C-09: Separating Perfusion and Diffusion Components From Diffusion Weighted MRI of Rectum Tumors Based On Intravoxel Incoherent Motion (IVIM) Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, N; Wengler, K; Mazaheri, Y; Hunt, M; Deasy, J; Gollub, M [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2014-06-15

    Purpose: Pseudodiffusion arises from the microcirculation of blood in the randomly oriented capillary network and contributes to the signal decay acquired using a multi-b value diffusion weighted (DW)-MRI sequence. This effect is more significant at low b-values and should be properly accounted for in apparent diffusion coefficient (ADC) calculations. The purpose of this study was to separate perfusion and diffusion component based on a biexponential and a segmented monoexponential model using IVIM analysis Methods. The signal attenuation is modeled as S(b) = S0[(1−f)exp(−bD) + fexp(−bD*)]. Fitting the biexponetial decay leads to the quantification of D, the true diffusion coefficient, D*, the pseudodiffusion coefficient, and f, the perfusion fraction. A nonlinear least squares fit and two segmented monoexponential models were used to derive the values for D, D*,‘and f. In the segmented approach b = 200 s/mm{sup 2} was used as the cut-off value for calculation of D. DW-MRI's of a rectum cancer patient were acquired before chemotherapy, before radiation therapy (RT), and 4 weeks into RT and were investigated as an example case. Results: Mean ADC for the tumor drawn on the DWI cases was 0.93, 1.0 and 1.13 10{sup −3}×mm{sup 2}/s before chemotherapy, before RT and 4 weeks into RT. The mean (D.10{sup −3} × mm{sup 2}/s, D* 10{sup −3} × mm{sup 2}/s, and f %) based on biexponential fit was (0.67, 18.6, and 27.2%), (0.72, 17.7, and 28.9%) and (0.83,15.1, and 30.7%) at these time points. The mean (D, D* f) based on segmented fit was (0.72, 10.5, and 12.1%), (0.72, 8.2, and 17.4%) and (.82, 8.1, 16.5%) Conclusion: ADC values are typically higher than true diffusion coefficients. For tumors with significant perfusion effect, ADC should be analyzed at higher b-values or separated from the perfusion component. Biexponential fit overestimates the perfusion fraction because of increased sensitivity to noise at low b-values.

  9. Early-stage differentiation between presenile Alzheimer's disease and frontotemporal dementia using arterial spin labeling MRI

    Energy Technology Data Exchange (ETDEWEB)

    Steketee, Rebecca M.E.; Meijboom, Rozanna; Lugt, Aad van der; Smits, Marion [Erasmus MC - University Medical Center, Department of Radiology, PO Box 2040, Rotterdam (Netherlands); Bron, Esther E.; Klein, Stefan [Erasmus MC - University Medical Center, Biomedical Imaging Group Rotterdam, Departments of Medical Informatics and Radiology, PO Box 2040, Rotterdam (Netherlands); Houston, Gavin C. [GE Healthcare, Hatfield (United Kingdom); Mutsaerts, Henri J.M.M. [Academic Medical Center, Department of Radiology, PO Box 22660, Amsterdam (Netherlands); Mendez Orellana, Carolina P. [Erasmus MC - University Medical Center, Department of Radiology, PO Box 2040, Rotterdam (Netherlands); Erasmus MC - University Medical Center, Department of Neurology, PO Box 2040, Rotterdam (Netherlands); Jong, Frank Jan de; Swieten, John C. van [Erasmus MC - University Medical Center, Department of Neurology, PO Box 2040, Rotterdam (Netherlands)

    2016-01-15

    To investigate arterial spin labeling (ASL)-MRI for the early diagnosis of and differentiation between the two most common types of presenile dementia: Alzheimer's disease (AD) and frontotemporal dementia (FTD), and for distinguishing age-related from pathological perfusion changes. Thirteen AD and 19 FTD patients, and 25 age-matched older and 22 younger controls underwent 3D pseudo-continuous ASL-MRI at 3 T. Gray matter (GM) volume and cerebral blood flow (CBF), corrected for partial volume effects, were quantified in the entire supratentorial cortex and in 10 GM regions. Sensitivity, specificity and diagnostic performance were evaluated in regions showing significant CBF differences between patient groups or between patients and older controls. AD compared with FTD patients had hypoperfusion in the posterior cingulate cortex, differentiating these with a diagnostic performance of 74 %. Compared to older controls, FTD patients showed hypoperfusion in the anterior cingulate cortex, whereas AD patients showed a more widespread regional hypoperfusion as well as atrophy. Regional atrophy was not different between AD and FTD. Diagnostic performance of ASL to differentiate AD or FTD from controls was good (78-85 %). Older controls showed global hypoperfusion compared to young controls. ASL-MRI contributes to early diagnosis of and differentiation between presenile AD and FTD. (orig.)

  10. Early-stage differentiation between presenile Alzheimer's disease and frontotemporal dementia using arterial spin labeling MRI

    International Nuclear Information System (INIS)

    To investigate arterial spin labeling (ASL)-MRI for the early diagnosis of and differentiation between the two most common types of presenile dementia: Alzheimer's disease (AD) and frontotemporal dementia (FTD), and for distinguishing age-related from pathological perfusion changes. Thirteen AD and 19 FTD patients, and 25 age-matched older and 22 younger controls underwent 3D pseudo-continuous ASL-MRI at 3 T. Gray matter (GM) volume and cerebral blood flow (CBF), corrected for partial volume effects, were quantified in the entire supratentorial cortex and in 10 GM regions. Sensitivity, specificity and diagnostic performance were evaluated in regions showing significant CBF differences between patient groups or between patients and older controls. AD compared with FTD patients had hypoperfusion in the posterior cingulate cortex, differentiating these with a diagnostic performance of 74 %. Compared to older controls, FTD patients showed hypoperfusion in the anterior cingulate cortex, whereas AD patients showed a more widespread regional hypoperfusion as well as atrophy. Regional atrophy was not different between AD and FTD. Diagnostic performance of ASL to differentiate AD or FTD from controls was good (78-85 %). Older controls showed global hypoperfusion compared to young controls. ASL-MRI contributes to early diagnosis of and differentiation between presenile AD and FTD. (orig.)

  11. 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...

  12. Implementation and evaluation of a new workflow for registration and segmentation of pulmonary MRI data for regional lung perfusion assessment

    Science.gov (United States)

    Böttger, T.; Grunewald, K.; Schöbinger, M.; Fink, C.; Risse, F.; Kauczor, H. U.; Meinzer, H. P.; Wolf, Ivo

    2007-03-01

    Recently it has been shown that regional lung perfusion can be assessed using time-resolved contrast-enhanced magnetic resonance (MR) imaging. Quantification of the perfusion images has been attempted, based on definition of small regions of interest (ROIs). Use of complete lung segmentations instead of ROIs could possibly increase quantification accuracy. Due to the low signal-to-noise ratio, automatic segmentation algorithms cannot be applied. On the other hand, manual segmentation of the lung tissue is very time consuming and can become inaccurate, as the borders of the lung to adjacent tissues are not always clearly visible. We propose a new workflow for semi-automatic segmentation of the lung from additionally acquired morphological HASTE MR images. First the lung is delineated semi-automatically in the HASTE image. Next the HASTE image is automatically registered with the perfusion images. Finally, the transformation resulting from the registration is used to align the lung segmentation from the morphological dataset with the perfusion images. We evaluated rigid, affine and locally elastic transformations, suitable optimizers and different implementations of mutual information (MI) metrics to determine the best possible registration algorithm. We located the shortcomings of the registration procedure and under which conditions automatic registration will succeed or fail. Segmentation results were evaluated using overlap and distance measures. Integration of the new workflow reduces the time needed for post-processing of the data, simplifies the perfusion quantification and reduces interobserver variability in the segmentation process. In addition, the matched morphological data set can be used to identify morphologic changes as the source for the perfusion abnormalities.

  13. Parkinson's disease-related perfusion and glucose metabolic brain patterns identified with PCASL-MRI and FDG-PET imaging

    Directory of Open Access Journals (Sweden)

    Laura K. Teune, MD, PhD

    2014-01-01

    Conclusion: We identified PD-related perfusion and metabolic brain patterns using PCASL and FDG-PET in the same patients which were comparable with results of existing research. In this respect, PCASL appears to be a promising addition in the early diagnosis of individual parkinsonian patients.

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

    Directory of Open Access Journals (Sweden)

    Jian-rui LI

    2015-03-01

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

  15. Validation of Fourier decomposition MRI with dynamic contrast-enhanced MRI using visual and automated scoring of pulmonary perfusion in young cystic fibrosis patients

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, Grzegorz, E-mail: g.bauman@dkfz.de [German Cancer Research Center, Division of Medical Physics in Radiology, Im Neuenheimer Feld 223, 69120 Heidelberg (Germany); Puderbach, Michael, E-mail: m.puderbach@dkfz.de [Chest Clinics at the University of Heidelberg, Clinics for Interventional and Diagnostic Radiology, Amalienstr. 5, 69126 Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (Germany); Heimann, Tobias, E-mail: t.heimann@dkfz.de [German Cancer Research Center, Division of Medical and Biological Informatics, Im Neuenheimer Feld 223, 69120 Heidelberg (Germany); Kopp-Schneider, Annette, E-mail: kopp@dkfz.de [German Cancer Research Center, Division of Biostatistics, Im Neuenheimer Feld 223, 69120 Heidelberg (Germany); Fritzsching, Eva, E-mail: eva.fritzsching@med.uni-heidelberg.de [University Hospital Heidelberg, Department of Translational Pulmonology and Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Im Neuenheimer Feld 430, Heidelberg (Germany); Mall, Marcus A., E-mail: marcus.mall@med.uni-heidelberg.de [Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (Germany); University Hospital Heidelberg, Department of Translational Pulmonology and Division of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center, Im Neuenheimer Feld 430, Heidelberg (Germany); Eichinger, Monika, E-mail: m.eichinger@dkfz.de [Translational Lung Research Center Heidelberg (TLRC), Member of the German Center for Lung Research (Germany); German Cancer Research Center, Division of Radiology, Im Neuenheimer Feld 223, 69120 Heidelberg (Germany)

    2013-12-01

    Purpose: To validate Fourier decomposition (FD) magnetic resonance (MR) imaging in cystic fibrosis (CF) patients with dynamic contrast-enhanced (DCE) MR imaging. Materials and methods: Thirty-four CF patients (median age 4.08 years; range 0.16–30) were examined on a 1.5-T MR imager. For FD MR imaging, sets of lung images were acquired using an untriggered two-dimensional balanced steady-state free precession sequence. Perfusion-weighted images were obtained after correction of the breathing displacement and Fourier analysis of the cardiac frequency from the time-resolved data sets. DCE data sets were acquired with a three-dimensional gradient echo sequence. The FD and DCE images were visually assessed for perfusion defects by two readers independently (R1, R2) using a field based scoring system (0–12). Software was used for perfusion impairment evaluation (R3) of segmented lung images using an automated threshold. Both imaging and evaluation methods were compared for agreement and tested for concordance between FD and DCE imaging. Results: Good or acceptable intra-reader agreement was found between FD and DCE for visual and automated scoring: R1 upper and lower limits of agreement (ULA, LLA): 2.72, −2.5; R2: ULA, LLA: ±2.5; R3: ULA: 1.5, LLA: −2. A high concordance was found between visual and automated scoring (FD: 70–80%, DCE: 73–84%). Conclusions: FD MR imaging provides equivalent diagnostic information to DCE MR imaging in CF patients. Automated assessment of regional perfusion defects using FD and DCE MR imaging is comparable to visual scoring but allows for percentage-based analysis.

  16. Validation of Fourier decomposition MRI with dynamic contrast-enhanced MRI using visual and automated scoring of pulmonary perfusion in young cystic fibrosis patients

    International Nuclear Information System (INIS)

    Purpose: To validate Fourier decomposition (FD) magnetic resonance (MR) imaging in cystic fibrosis (CF) patients with dynamic contrast-enhanced (DCE) MR imaging. Materials and methods: Thirty-four CF patients (median age 4.08 years; range 0.16–30) were examined on a 1.5-T MR imager. For FD MR imaging, sets of lung images were acquired using an untriggered two-dimensional balanced steady-state free precession sequence. Perfusion-weighted images were obtained after correction of the breathing displacement and Fourier analysis of the cardiac frequency from the time-resolved data sets. DCE data sets were acquired with a three-dimensional gradient echo sequence. The FD and DCE images were visually assessed for perfusion defects by two readers independently (R1, R2) using a field based scoring system (0–12). Software was used for perfusion impairment evaluation (R3) of segmented lung images using an automated threshold. Both imaging and evaluation methods were compared for agreement and tested for concordance between FD and DCE imaging. Results: Good or acceptable intra-reader agreement was found between FD and DCE for visual and automated scoring: R1 upper and lower limits of agreement (ULA, LLA): 2.72, −2.5; R2: ULA, LLA: ±2.5; R3: ULA: 1.5, LLA: −2. A high concordance was found between visual and automated scoring (FD: 70–80%, DCE: 73–84%). Conclusions: FD MR imaging provides equivalent diagnostic information to DCE MR imaging in CF patients. Automated assessment of regional perfusion defects using FD and DCE MR imaging is comparable to visual scoring but allows for percentage-based analysis

  17. A hybrid breath hold and continued respiration-triggered technique for time-resolved 3D MRI perfusion studies in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hintze, C. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany). Radiologie; Stemmer, A. [Siemens AG (Germany). Healthcare Sector; Bock, M. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (DE). Medizinische Physik in der Radiologie] (and others)

    2010-01-15

    Assessment of lung cancer perfusion is impaired by respiratory motion. Imaging times for contrast agent wash-out studies often exceed breath hold capabilities, and respiration triggering reduces temporal resolution. Temporally resolved volume acquisition of entire tumors is required to assess heterogeneity. Therefore, we developed and evaluated an MR measurement technique that exceeds a single breath hold, and provides a variable temporal resolution during acquisition while suspending breath-dependent motion. 20 patients with suspected lung cancer were subjected to perfusion studies using a spoiled 3D gradient echo sequence after bolus injection of 0.07 mmol/kg body weight of Gd-DTPA. 10 acquisitions in expiratory breath hold were followed by 50 navigator-triggered acquisitions under free breathing. Post-processing allowed for co-registration of the 3D data sets. An ROI-based visualization of the signal-time curves was performed. In all cases motion-suspended, time-resolved volume data sets (40 x 33 x 10 cm{sup 3}, voxel size: 2.1 x 2.1 x 5.0 mm{sup 3}) were generated with a variable, initially high temporal resolution (2.25 sec) that was synchronized with the breath pattern and covered up to 8(1)/(2) min. In 7 / 20 cases a remaining offset could be reduced by rigid co-registration. The tumors showed fast wash-in, followed by rapid signal decay (8 / 20) or a plateau. The feasibility of a perfusion study with hybrid breath hold and navigator-triggered time-resolved 3D MRI which combines high initial temporal resolution during breath hold with a long wash-out period under free breathing was demonstrated. (orig.)

  18. A hybrid breath hold and continued respiration-triggered technique for time-resolved 3D MRI perfusion studies in lung cancer

    International Nuclear Information System (INIS)

    Assessment of lung cancer perfusion is impaired by respiratory motion. Imaging times for contrast agent wash-out studies often exceed breath hold capabilities, and respiration triggering reduces temporal resolution. Temporally resolved volume acquisition of entire tumors is required to assess heterogeneity. Therefore, we developed and evaluated an MR measurement technique that exceeds a single breath hold, and provides a variable temporal resolution during acquisition while suspending breath-dependent motion. 20 patients with suspected lung cancer were subjected to perfusion studies using a spoiled 3D gradient echo sequence after bolus injection of 0.07 mmol/kg body weight of Gd-DTPA. 10 acquisitions in expiratory breath hold were followed by 50 navigator-triggered acquisitions under free breathing. Post-processing allowed for co-registration of the 3D data sets. An ROI-based visualization of the signal-time curves was performed. In all cases motion-suspended, time-resolved volume data sets (40 x 33 x 10 cm3, voxel size: 2.1 x 2.1 x 5.0 mm3) were generated with a variable, initially high temporal resolution (2.25 sec) that was synchronized with the breath pattern and covered up to 8(1)/(2) min. In 7 / 20 cases a remaining offset could be reduced by rigid co-registration. The tumors showed fast wash-in, followed by rapid signal decay (8 / 20) or a plateau. The feasibility of a perfusion study with hybrid breath hold and navigator-triggered time-resolved 3D MRI which combines high initial temporal resolution during breath hold with a long wash-out period under free breathing was demonstrated. (orig.)

  19. Computational Fluid Dynamics Simulations of Contrast Agent Bolus Dispersion in a Coronary Bifurcation: Impact on MRI-Based Quantification of Myocardial Perfusion

    Directory of Open Access Journals (Sweden)

    Regine Schmidt

    2013-01-01

    Full Text Available Contrast-enhanced first-pass magnetic resonance imaging (MRI in combination with a tracer kinetic model, for example, MMID4, can be used to determine myocardial blood flow (MBF and myocardial perfusion reserve (MPR. Typically, the arterial input function (AIF required for this methodology is estimated from the left ventricle (LV. Dispersion of the contrast agent bolus might occur between the LV and the myocardial tissue. Negligence of bolus dispersion could cause an error in MBF determination. The aim of this study was to investigate the influence of bolus dispersion in a simplified coronary bifurcation geometry including one healthy and one stenotic branch on the quantification of MBF and MPR. Computational fluid dynamics (CFD simulations were combined with MMID4. Different inlet boundary conditions describing pulsatile and constant flows for rest and hyperemia and differing outflow conditions have been investigated. In the bifurcation region, the increase of the dispersion was smaller than inside the straight vessels. A systematic underestimation of MBF values up to −16.1% for pulsatile flow and an overestimation of MPR up to 7.5% were found. It was shown that, under the conditions considered in this study, bolus dispersion can significantly influence the results of quantitative myocardial MR-perfusion measurements.

  20. Facing Contrast-Enhancing Gliomas: Perfusion MRI in Grade III and Grade IV Gliomas according to Tumor Area

    Directory of Open Access Journals (Sweden)

    Anna Luisa Di Stefano

    2014-01-01

    Full Text Available Tumoral neoangiogenesis characterizes high grade gliomas. Relative Cerebral Blood Volume (rCBV, calculated with Dynamic Susceptibility Contrast (DSC Perfusion-Weighted Imaging (PWI, allows for the estimation of vascular density over the tumor bed. The aim of the study was to characterize putative tumoral neoangiogenesis via the study of maximal rCBV with a Region of Interest (ROI approach in three tumor areas—the contrast-enhancing area, the nonenhancing tumor, and the high perfusion area on CBV map—in patients affected by contrast-enhancing glioma (grades III and IV. Twenty-one patients were included: 15 were affected by grade IV and 6 by grade III glioma. Maximal rCBV values for each patient were averaged according to glioma grade. Although rCBV from contrast-enhancement and from nonenhancing tumor areas was higher in grade IV glioma than in grade III (5.58 and 2.68; 3.01 and 2.2, resp., the differences were not significant. Instead, rCBV recorded in the high perfusion area on CBV map, independently of tumor compartment, was significantly higher in grade IV glioma than in grade III (7.51 versus 3.78, P=0.036. In conclusion, neoangiogenesis encompasses different tumor compartments and CBV maps appear capable of best characterizing the degree of neovascularization. Facing contrast-enhancing brain tumors, areas of high perfusion on CBV maps should be considered as the reference areas to be targeted for glioma grading.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-01

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

  2. Accuracy of F-DOPA PET and perfusion-MRI for differentiating radionecrotic from progressive brain metastases after radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Cicone, Francesco; Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; ' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Minniti, Giuseppe; Scaringi, Claudia; Maurizi Enrici, Riccardo [' ' Sapienza' ' Univ., Rome (Italy). Dept. of Surgical and Medicine Sciences and Translational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Romano, Andrea; Tavanti, Francesca; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.)

    2015-01-15

    We assessed the performance of 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET for differentiating radionecrosis (RN) from tumour progression (PD) in a population of patients with brain metastases, treated with stereotactic radiosurgery. The accuracy of F-DOPA PET was compared with that of perfusion-weighted magnetic resonance (perfusion-MR). In 42 patients with a total of 50 brain metastases from various primaries F-DOPA PET/CT was performed because of suspected radiological progression at the site of previously irradiated brain metastasis. Several semiquantitative PET parameters were recorded, and their diagnostic accuracy was compared by receiver operating characteristic curve analyses. The diagnosis was established by either surgery or follow-up. A comparison was made between F-DOPA PET and perfusion-MR sequences acquired no more than 3 weeks apart. Definitive outcome was available in 46 of the 50 lesions (20 PD, 26 RN). Of the 46 lesions, 11 were surgically excised while in the remaining 35 lesions the diagnosis was established by radiological and clinical criteria. The best diagnostic performance was obtained using the semiquantitative PET parameter maximum lesion to maximum background uptake ratio (SUVL{sub max}/Bkgr{sub max}). With a cut-off value of 1.59, a sensitivity of 90 % and a specificity of 92.3 % were achieved in differentiating RN from PD lesions (accuracy 91.3 %). Relative cerebral blood volume (rCBV) derived from perfusion-MR was available for comparison in 37 of the 46 metastases. Overall accuracy of rCBV was lower than that of all semiquantitative PET parameters under study. The best differentiating rCBV cut-off value was 2.14; this yielded a sensitivity of 86.7 % and a specificity of 68.2 % (accuracy 75.6 %). F-DOPA PET is a highly accurate tool for differentiating RN from PD brain metastases after stereotactic radiosurgery. In this specific setting, F-DOPA PET seems to perform better than perfusion-MR. (orig.)

  3. High-temporospatial-resolution dynamic contrast-enhanced (DCE) wrist MRI with variable-density pseudo-random circular Cartesian undersampling (CIRCUS) acquisition: evaluation of perfusion in rheumatoid arthritis patients.

    Science.gov (United States)

    Liu, Jing; Pedoia, Valentina; Heilmeier, Ursula; Ku, Eric; Su, Favian; Khanna, Sameer; Imboden, John; Graf, Jonathan; Link, Thomas; Li, Xiaojuan

    2016-01-01

    This study is to evaluate highly accelerated three-dimensional (3D) dynamic contrast-enhanced (DCE) wrist MRI for assessment of perfusion in rheumatoid arthritis (RA) patients. A pseudo-random variable-density undersampling strategy, circular Cartesian undersampling (CIRCUS), was combined with k-t SPARSE-SENSE reconstruction to achieve a highly accelerated 3D DCE wrist MRI. Two healthy volunteers and 10 RA patients were studied. Two patients were on methotrexate (MTX) only (Group I) and the other eight were treated with a combination therapy of MTX and anti-tumor necrosis factor (TNF) therapy (Group II). Patients were scanned at baseline and 3 month follow-up. DCE MR images were used to evaluate perfusion in synovitis and bone marrow edema pattern in the RA wrist joints. A series of perfusion parameters was derived and compared with clinical disease activity scores of 28 joints (DAS28). 3D DCE wrist MR images were obtained with a spatial resolution of 0.3 × 0.3 × 1.5 mm(3) and temporal resolution of 5 s (with an acceleration factor of 20). The derived perfusion parameters, most notably transition time (dT) of synovitis, showed significant negative correlations with DAS28-ESR (r = -0.80, p perfusion in RA joints, showing promise as a potential tool for evaluating treatment responses.

  4. Feasibility of 3D Partially Parallel Acquisition DCE MRI in Pulmonary Parenchyma Perfusion%三维并行采集动态增强MRI在肺实质局部灌注中的应用研究

    Institute of Scientific and Technical Information of China (English)

    夏艺; 范丽; 刘士远; 管宇; 徐雪原; 于红; 肖湘生

    2012-01-01

    目的 评价3D并行采集动态对比增强MRI(dynamic contrast-enhanced MRI,DCE-MRI)技术对肺实质局部灌注成像的可行性.资料与方法 采用GE 1.5 T MRI系统,对10名健康志愿者及47例肺部疾病患者行灌注成像;评价肺灌注图像的均匀度,若存在灌注异常区域则计算其与正常肺组织的信号强度之比( RSI).结果 DCE-MRI可以清楚地显示肺实质灌注情况:10名健康志愿者的灌注图像较均匀,未见灌注缺损区.10例肺动脉栓塞( pulmonary embolism,PE)共出现12个楔形灌注缺损区,其中1例双侧PE出现3个灌注缺损区;12例侵犯邻近肺动脉的肺癌,在相应供血区均出现灌注缺损;RSI经单样本t检验差异具有明显的统计学意义(t=-24.74,P<0.05);另25例(20例未侵犯邻近肺动脉的肺癌和5例炎性病变)在对比剂首过肺实质强化达峰值时,病灶局部均呈低信号改变.结论 3D并行采集DCE-MRI技术可在单次屏气状态下完成动态多期扫描,获得全肺的容积灌注成像数据,对MR肺灌注图像采用半量化分析可明显区分出灌注异常区与灌注正常区.%Objective To assess the feasibility of 3 D partially parallel acquisition dynamic contrast enhanced (DCE) MRI in pulmonary parenchyma perfusion. Materials and Methods Ten healthy volunteers and 47 patients with lung disease performed perfusion imaging on a clinical 1. 5-T GE Excite HD whole body system. The homogeneity of perfusion images were assessed. In case of perfusion abnormality, the signal intensity ratio ( RSI) of perfusion abnormality and normal lung were calculated. Results Pulmonary parenchyma perfusion was well depicted with DCE-MRI. The perfusion images of healthy volunteers were homogeneous. 12 wedge shaped perfusion defects were visualized in 10 patients with pulmonary embolisms. 12 perfusion defects were also showed in 12 patients with lung cancer infiltrating the pulmonary artery. There was significant difference in RSI (t = - 24

  5. Measurement of the arterial concentration of Gd-DTPA using MRI: a step toward quantitative perfusion imaging

    DEFF Research Database (Denmark)

    Fritz-Hansen, T; Rostrup, Egill; Larsson, H B;

    1996-01-01

    accordance between the two input functions was found, indicating that it is possible to measure the input function to the myocardium using MRI. A variation between the two concentration curves of 5% at upslope, 2.7% at peak point, and 7% at downslope was found. The study also indicates that a short...

  6. Tumor metabolism and perfusion ratio assessed by 18F-FDG PET/CT and DCE-MRI in breast cancer patients: Correlation with tumor subtype and histologic prognostic factors

    Energy Technology Data Exchange (ETDEWEB)

    An, Young-Sil [Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine (Korea, Republic of); Kang, Doo Kyoung [Department of Radiology, Ajou University School of Medicine (Korea, Republic of); Jung, Yong Sik; Han, Sehwan [Department of Surgery, Ajou University School of Medicine (Korea, Republic of); Kim, Tae Hee, E-mail: medhand@ajou.ac.kr [Department of Radiology, Ajou University School of Medicine (Korea, Republic of)

    2015-07-15

    Highlights: • In non-triple negative breast cancer, metabolic parameter (SUVmax) was significantly correlated with perfusion parameters (Kep and Ve). • In triple negative cancers, any perfusion parameters did not correlated with metabolic parameters. • Higher SUVmax, higher SUVmax/Ktrans, higher MTV50/Ktrans, higher TLG50/Ktrans, higher TLG50/Ve ratios were significantly correlated with TNBC. • In triple negative breast cancer, perfusion and metabolic parameters are not significantly correlated. • Triple negative breast cancer showed higher metabolic–perfusion ratios compared to non-triple negative breast cancer. - Abstract: Objective: Our purpose was to evaluate whether breast cancer with high metabolic–perfusion ratio would be associated with poor histopathologic prognostic factors and whether triple negative breast cancer (TNBC) would show high metabolic–perfusion ratio compared to non-triple negative breast cancer (non-TNBC). Methods: From March 2011 to November 2011, 67 females with invasive ductal carcinoma of breast who underwent both MRI and 18F-FDG PET/CT were included. Perfusion parameters including Ktrans, Kep and Ve were acquired from Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Metabolic parameters including the standardized uptake value (SUV) and volumetric metabolic parameters including metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were obtained from F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). Results: In non-TNBC, SUVmax was significantly correlated with Kep (ρ = 0.298, p = 0.036) and Ve (ρ = −0.286, p = 0.044). In TNBC, there was no significant correlation between all perfusion and metabolic parameters. Compared to non-TNBC, higher SUVmax (10.2 vs 5.3, p < 0.001), higher SUVmax/Ktrans (56.02 vs 20.3, p < 0.001), higher MTV50/Ktrans (7.8 vs 16.54, p < 0.001), higher TLG50/Ktrans (36.49 vs 12.3, p < 0.001), higher TLG50/Ve (91.34 vs 27.1 p = 0.022) were

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

    Science.gov (United States)

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

    2015-12-01

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

  8. Hepatic necro-inflammation and elevated liver enzymes: Evaluation with MRI perfusion imaging with gadoxetic acid in chronic hepatitis patients

    International Nuclear Information System (INIS)

    Aim: To evaluate liver necro-inflammation and function by using gadoxetic acid-enhanced dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), with histological analysis as the reference standard. Materials and methods: Seventy-nine subjects (21 healthy subjects; 58 chronic hepatitis patients) who received gadoxetic acid-enhanced DCE-MRI were divided into three subgroups: no (A0, n = 31), mild (A1, n = 27), and moderate–severe (A2–A3, n = 21) activities. Two DCE-MRI models were measured: (1) a dual-input single-compartment model to obtain absolute arterial, portal venous, and total blood flow, arterial fraction (ART), distribution volume, and mean transit time; (2) a curve analysis method to obtain peak, slope, and AUC (area under curve). The serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels also obtained. Statistical testing included Kruskal–Wallis tests for continuous data, Pearson's correlation tests, and multiple linear regression analyses. Results: Hepatic necro-inflammatory activity grades were significantly correlated with fibrotic stages, serum ALT level, ART and AUC. ART was helpful to predict the mild activity (≤A1 versus >A1; Az = 0.728), whereas AUC could differentiate no activity from any activity (A0 versus >A0; Az = 0.703). Peak, slope and AUC were all associated with AST and ALT (p < 0.05). Conclusion: Gadoxetic acid-enhanced DCE-MRI parameters may be used to evaluate the severity of hepatic necro-inflammation and function

  9. Comparison of the PET with fluoro-ethyl-tyrosine to perfusion MRI and T1 injected in the exploration of glial tumors: a pilot study; Comparaison de la TEP a la fluoro-ethyl-tyrosine a l'IRM de perfusion et T1 injectee dans l'exploration des tumeurs gliales: une etude pilote

    Energy Technology Data Exchange (ETDEWEB)

    Cazzola, V.; Payoux, P.; Esquerre' , J.P.; Wagner, T.; Julian, A. [CHU Toulouse-Purpan, Service de medecine nucleaire, 31 (France); Benouaich, A. [CHU Toulouse-Purpan, Service de neurologie, 31 (France); Catalaa, I. [CHU Rangueil, service de neuroradiologie, 31 - Toulouse (France); Alonso, M. [CHU Purpan, service de radiopharmacie, 31 - Toulouse (France)

    2010-07-01

    Molecular imaging could be used in complement of MRI injected in the initial result of cerebral tumors. This study has for aim to compare the performances of the positron computed tomography with fluoro-ethyl-tyrosine (F.E.T.) with the T1 sequences with gadolinium injection and perfusion MRI in the staging of glial tumors. In spite of the low strength of the series, the cerebral PET shows a good performance in the staging of glial tumors, without being superior to MRI. however, the results seem interesting in view of possible merging to allow targeting at the best, the biopsies, especially for the injuries classified high grade for MRI without contrast after gadolinium injection. (N.C.)

  10. A description of ASL features in writing

    Directory of Open Access Journals (Sweden)

    Kimberly A. Wolbers

    2014-01-01

    Full Text Available Similar to second language students who embed features of their primary languages in the writing of their second languages, deaf and hard of hearing (d/hh writers utilize features of American Sign Language (ASL in their writing of English. The purpose of this study is to identify categories of language transfer, provide the prevalence of these transfer tendencies in the writings of 29 d/hh adolescents and describe whether language features are equally or differently responsive to instruction. Findings indicate six categories of language transfer in order of prevalence: unique glossing & substitution, adjectives, plurality & adverbs, topicalization, and conjunctions. ASL features, of both lexical and syntactical nature, appear to respond similarly to instruction.

  11. MSCT and MRI Findings of Transient Hepatic Perfusion Disorders in Patients with Hepatic Abscess%肝脓肿邻近肝实质一过性灌注异常的CT和MRI表现

    Institute of Scientific and Technical Information of China (English)

    沈文东; 李惠民

    2012-01-01

    目的:探讨肝脓肿伴发的一过性肝灌注异常(THPD)的影像表现及其主要机制.方法:回顾性分析CT上明确显示THPD的19例肝脓肿患者的CT和MRI资料,男9例,女10例,年龄35~82岁,平均62.8±13.8岁.全部完成16层CT与MRI的平扫和增强.结果:CT增强显示16例高灌注THPD,3例低灌注THPD,MRI增强T1WI显示14例高灌注THPD,4例低灌注THPD,1例未见灌注异常.常规T2WI显示灌注异常区高信号16例(84.2%).CT和MRI灌注表现一致15例(78.9%),不一致4例,其低或等灌注的检查均先于高灌注的检查.结论:脓肿伴发的一过性肝灌注异常的CT和MRI表现一致,较早期可以表现为低灌注,后期均为高灌注.MR T2WI可以很好显示THPD,有助于诊断.%Purpose: To evaluate the CT and MRI findings of transient hepatic perfusion disorders (THPD) in patients with hepatic abscess and explore their main mechanism. Methods: Nineteen hepatic abscess patients (9 male, 10 female, age ranging from 35 to 82, mean 62.8± 13.8 years) with THPD diagnosed on CT images were enrolled in our study. All patients were undergone non-contrasted and contrasted scanning with a 16-slice CT scanner and 1.5T MRI scanner. Results: Hyper-perfusion THPD in 16 patients and hypo-perfusion THPD in 3 patients were shown on CT scans. Hyper-perfusion THPD in 14 patients and hypo-perfusion THPD in 4 patients were shown on MRI scans. The THPD region was hyper-intensity in 16 patients(84.2%). Fifteen THPD shown on MRI were consistent with that on CT (78.9%). The other 4 THPD lesions were first shown with hypo- or iso-perfusion and lastly shown with hyper-perfusion. Conclusion: The THPD in patients with hepatic abscess have the same perfusion findings on CT and MRI. There may be hypo-perfusion during early phase and hyper-perfusion during late phase of hepatic abscess. T2-weighed imaging could reveal the THPD correctly and may be helpful for the diagnosis.

  12. 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.

  13. Diffusion and perfusion MRI in patients with ruptured and unruptured intracranial aneurysms treated by endovascular coiling: complications, procedural results, MR findings and clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Cronqvist, M.; Ramgren, B.; Holtaas, S.; Larsson, E.-M. [Lund University Hospital, Department of Neuroradiology, Lund (Sweden); Wirestam, R. [Lund University Hospital, Department of Radiation Physics, Lund (Sweden); Brandt, L.; Nilsson, O.; Saeveland, H. [Lund University Hospital, Department of Neurosurgery, Lund (Sweden)

    2005-11-01

    Our purpose was to evaluate treatment safety as well as complications frequency and management in endovascular coiling of intracerebral aneurysms using MR diffusion and perfusion imaging. In this prospective study, 77 MR examinations were performed in conjunction with 43 procedures in 40 patients, 14 patients presented with ruptured and 26 with unruptured aneurysms. Mean time interval between treatment and post-procedure MRI was 29 and 25 h for the ruptured and unruptured aneurysm group, respectively. Peri-procedural complications, including five major events and five minor transient events, occurred in 10/43 procedures (23%), necessitating thrombolytic therapy in two patients and angioplasty in one, all three within the unruptured aneurysm group. Fifty-one new lesions were found on post-treatment DWI and 47 of them were regarded as of ischemic origin. Most lesions were small (<3 mm), ipsilateral to the treated aneurysm and asymptomatic (37/40 patients). Sixty-seven percent of the lesions were found in the ruptured and 33% in the unruptured aneurysm group. The ischemic lesions did occur more frequently in patients treated for aneurysm of large neck size and according to the remodelling technique. The overall morbidity and mortality rates were 14.6 and 7.3% whereas morbidity and mortality rates related to the technique were only 2.6 and 0%, respectively. (orig.)

  14. Can SEE-2 Children Understand ASL-Using Adults?

    Science.gov (United States)

    Luetke-Stahlman, Barbara

    1990-01-01

    The study compared comprehension of American Sign Language (ASL) between 12 deaf subjects in a program using Signing Exact English (SEE-2) and 14 deaf subjects in a residential program using Signed English, Pidgin Signed English, and ASL. Students exposed to SEE-2 could comprehend ASL as well as residential school peers. (Author/DB)

  15. Theoretical considerations in measurement of time discrepancies between input and myocardial time-signal intensity curves in estimates of regional myocardial perfusion with first-pass contrast-enhanced MRI.

    Science.gov (United States)

    Natsume, Takahiro; Ishida, Masaki; Kitagawa, Kakuya; Nagata, Motonori; Sakuma, Hajime; Ichihara, Takashi

    2015-11-01

    The purpose of this study was to develop a method to determine time discrepancies between input and myocardial time-signal intensity (TSI) curves for accurate estimation of myocardial perfusion with first-pass contrast-enhanced MRI. Estimation of myocardial perfusion with contrast-enhanced MRI using kinetic models requires faithful recording of contrast content in the blood and myocardium. Typically, the arterial input function (AIF) is obtained by setting a region of interest in the left ventricular cavity. However, there is a small delay between the AIF and the myocardial curves, and such time discrepancies can lead to errors in flow estimation using Patlak plot analysis. In this study, the time discrepancies between the arterial TSI curve and the myocardial tissue TSI curve were estimated based on the compartment model. In the early phase after the arrival of the contrast agent in the myocardium, the relationship between rate constant K1 and the concentrations of Gd-DTPA contrast agent in the myocardium and arterial blood (LV blood) can be described by the equation K1={dCmyo(tpeak)/dt}/Ca(tpeak), where Cmyo(t) and Ca(t) are the relative concentrations of Gd-DTPA contrast agent in the myocardium and in the LV blood, respectively, and tpeak is the time corresponding to the peak of Ca(t). In the ideal case, the time corresponding to the maximum upslope of Cmyo(t), tmax, is equal to tpeak. In practice, however, there is a small difference in the arrival times of the contrast agent into the LV and into the myocardium. This difference was estimated to correspond to the difference between tpeak and tmax. The magnitudes of such time discrepancies and the effectiveness of the correction for these time discrepancies were measured in 18 subjects who underwent myocardial perfusion MRI under rest and stress conditions. The effects of the time discrepancies could be corrected effectively in the myocardial perfusion estimates.

  16. Temporal and extra-temporal hypoperfusion in medial temporal lobe epilepsy evaluated by arterial-spin-labeling based MRI

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy (mTLE) by using arterial-spin-labeling (ASL) based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status. Methods: Twenty-five patients with left-sided and 23 with right-sided mTLE were enrolled, and 30 healthy volunteers were recruited. The cerebral blood flow (CBF) of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner. The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis. The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the normal side in matched region in mTLE group. Results: Compared with the volunteers, the patients with mTLE showed the decrease of CBF in the bilateral medial and lateral temporal, the frontal and parietal regions relating to the default-mode network and more serious in lesion side. The CBF values of the medial temporal lobe were negatively correlated with the epilepsy duration (r=-0.51, P<0.01). The asymmetric index of CBF as-0.01 has a 76.0% (19/25) sensitivity and a 78.3% (18/23) specificity to distinguish the lesion side. Conclusions: The decrease of CBF in the temporal and extra-temporal region by ASL-based MRI suggests the functional abnormalities in the network involved by mTLE. The ASL technique is a useful tool for lateralizing the unilateral mTLE. (authors)

  17. Application of MRS and ASL in the diagnosis of pseudoprogression in high-grade glioma%MRS联合ASL在高级别脑胶质瘤假性进展诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    王季华; 张在云; 李晓梅; 程健; 姜玉华

    2016-01-01

    目的:探讨磁共振波谱分析技术( magnetic resonance spectroscopy, MRS)联合动脉自旋标记技术( arterial spin labeling, ASL)在高级别脑胶质瘤假性进展诊断中的应用。方法回顾性分析我院2013年1月~2015年12月高级别脑胶质瘤行手术及术后联合替莫唑胺放化疗1月后MRI上出现水肿及增强范围扩大者36例,应用MRS分析病灶局部代谢产物及其比值情况,ASL分析病灶局部血流情况。评价2种方法在高级别脑胶质瘤假性进展诊断中的意义。结果36例患者中,经二次手术病理或随访10月以上证实28例为假性进展,8例为肿瘤复发。单纯应用MRS、ASL及二者联合正确诊断假性进展者分别为19例、23例及26例。假性进展表现:MRS图像Cho/Cr下降及NAA/Cr下降, ASL出现病变区低灌注;肿瘤复发表现:MRS图像Cho/Cr升高及NAA/Cr下降,ASL出现病变区高灌注。结论联合应用MRS及ASL分析可较好地诊断胶质瘤假性进展,具有良好的临床应用前景。%Objective To investigate magnetic resonance spectroscopy ( MRS) and arterial spin labeling ( ASL) in the diag-nosis of pseudoprogression in high-grade glioma.Methods 36 high-grade glioma patients who had presented with enlarged con-trast-enhanced lesions on magnetic resonance imaging ( MRI) one month after completing concurrent chemoradiotherapy were en-rolled in the second hospital of shandong university from Jan 2013 to Dec 2015.Metabolites and their ratio were analyzed with MRS, blood flow was measured with ASL, both of MRS and ASL were applied to determine whether there was pseudoprogression or tumor recurrence in the lesion area.Results In 36 cases, 28 cases were confirmed as pseudoprogression, 8 cases as recur-rence, by re-surgery or with follow-up for 10 months.Pseudoprogression diagnosed by MRS, ASL and combination were 19 cases, 23 cases and 26 cases respectively.Decreased Cho/Cr and NAA/Cr were shown in MRS

  18. MR Diagnosis of a Pulmonary Embolism: Comparison of P792 and Gd-DOTA for First-Pass Perfusion MRI and Contrast-Enhanced 3D MRA in a Rabbit Model

    Energy Technology Data Exchange (ETDEWEB)

    Keilholz, Shella D. [Emory University and Georgia Institute of Technology, Atlanta (United States); Bozlar, Ugur; Fujiwara, Naomi; Mata, Jaime F.; Berr, Stuart S.; Hagspiel, Klaus D. [Gulhane Military Medical Academy, Ankara (Turkmenistan); Corot, Claire [Guerbet Research, Aulnay-sous-Bois (France)

    2009-10-15

    To compare P792 (gadomelitol, a rapid clearance blood pool MR contrast agent) with gadolinium-tetraazacyclododecanetetraacetic acid (Gd- DOTA), a standard extracellular agent, for their suitability to diagnose a pulmonary embolism (PE) during a first-pass perfusion MRI and 3D contrastenhanced (CE) MR angiography (MRA). A perfusion MRI or CE-MRA was performed in a rabbit PE model following the intravenous injection of a single dose of contrast agent. The time course of the pulmonary vascular and parenchymal enhancement was assessed by measuring the signal in the aorta, pulmonary artery, and lung parenchyma as a function of time to determine whether there is a significant difference between the techniques. CE-MRA studies were evaluated by their ability to depict the pulmonary vasculature and following defects between 3 seconds and 15 minutes after a triple dose intravenous injection of the contrast agents. The P792 and Gd-DOTA were equivalent in their ability to demonstrate PE as perfusion defects on first pass imaging. The signal from P792 was significantly higher in vasculature than that from Gd-DOTA between the first and the tenth minutes after injection. The results suggest that a CE-MRA PE could be reliably diagnosed up to 15 minutes after injection. P792 is superior to Gd-DOTA for the MR diagnosis of PE.

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

    Directory of Open Access Journals (Sweden)

    Anna Tietze

    Full Text Available Deficient microvascular blood flow control is thought to cause tumor hypoxia and increase resistance to therapy. In glioma patients, we tested whether perfusion-weighted MRI (PWI based indices of microvascular flow control provide more information on tumor grade and patient outcome than does the established PWI angiogenesis marker, cerebral blood volume (CBV.Seventy-two glioma patients (sixty high-grade, twelve low-grade gliomas were included. Capillary transit time heterogeneity (CTH and the coefficient of variation (COV, its ratio to blood mean transit time, provide indices of microvascular flow control and the extent to which oxygen can be extracted by tumor tissue. The ability of these parameters and CBV to differentiate tumor grade were assessed by receiver operating characteristic curves and logistic regression. Their ability to predict time to progression and overall survival was examined by the Cox proportional-hazards regression model, and by survival curves using log-rank tests.The best prediction of grade (AUC = 0.876; p < 0.05 was achieved by combining knowledge of CBV and CTH in the enhancing tumor and peri-focal edema, and patients with glioblastoma multiforme were identified best by CTH (AUC = 0.763; p<0.001. CTH outperformed CBV and COV in predicting time to progression and survival in all gliomas and in a subgroup consisting of only high-grade gliomas.Our study confirms the importance of microvascular flow control in tumor growth by demonstrating that determining CTH improves tumor grading and outcome prediction in glioma patients compared to CBV alone.

  20. Volumetric assessment of recurrent or progressive gliomas: comparison between F-DOPA PET and perfusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cicone, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Filss, Christian P.; Langen, Karl-Josef [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; RWTH Aachen Univ. Hospital (Germany). Dept. of Nuclear Medicine; Minniti, Giuseppe; Scaringi, Claudia [Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Sant' Andrea Hospital, Rome (Italy). Unit of Radiotherapy; Rossi-Espagnet, Camilla; Bozzao, Alessandro [Sant' Andrea Hospital, Rome (Italy). Unit of Neuroradiology; Rome Sapienza Univ. (Italy). Dept. of Neurosciences, Mental Health and Sensory Organs (Ne.S.M.O.S.); Papa, Annalisa; Scopinaro, Francesco [Sant' Andrea Hospital, Rome (Italy). Unit of Nuclear Medicine; Rome Sapienza Univ. (Italy). Dept. of Surgical and Medical Sciences and tranlational Medicine; Galldiks, Norbert [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine; Cologne Univ. (Germany). Dept. of Neurology; Shah, N. Jon [Research Centre Juelich (Germany). Inst. of Neureoscience and Medicine

    2015-05-01

    To compare the diagnostic information obtained with 6-[{sup 18}F]-fluoro-l-3,4-dihydroxyphenylalanine (F-DOPA) PET and relative cerebral blood volume (rCBV) maps in recurrent or progressive glioma. All patients with recurrent or progressive glioma referred for F-DOPA imaging at our institution between May 2010 and May 2014 were retrospectively included, provided that macroscopic disease was visible on conventional MRI images and that rCBV maps were available for comparison. The final analysis included 50 paired studies (44 patients). After image registration, automatic tumour segmentation of both sets of images was performed using the average signal in a large reference VOI including grey and white matter multiplied by 1.6. Tumour volumes identified by both modalities were compared and their spatial congruence calculated. The distances between F-DOPA uptake and rCBV hot spots, tumour-to-brain ratios (TBRs) and normalized histograms were also computed. On visual inspection, 49 of the 50 F-DOPA and 45 of the 50 rCBV studies were classified as positive. The tumour volume delineated using F-DOPA (F-DOPA{sub vol} {sub 1.6}) greatly exceeded that of rCBV maps (rCBV{sub vol} {sub 1.6}). The median F-DOPA{sub vol} {sub 1.6} and rCBV{sub vol} {sub 1.6} were 11.44 ml (range 0 - 220.95 ml) and 1.04 ml (range 0 - 26.30 ml), respectively (p < 0.00001). Overall, the median overlapping volume was 0.27 ml, resulting in a spatial congruence of 1.38 % (range 0 - 39.22 %). The mean hot spot distance was 27.17 mm (±16.92 mm). F-DOPA uptake TBR was significantly higher than rCBV TBR (1.76 ± 0.60 vs. 1.15 ± 0.52, respectively; p < 0.0001). The histogram analysis showed that F-DOPA provided better separation of tumour from background. In 6 of the 50 studies (12 %), however, physiological uptake in the striatum interfered with tumour delineation. The information provided by F-DOPA PET and rCBV maps are substantially different. Image interpretation is easier and a larger tumour extent

  1. Advances in functional and structural imaging of the human lung using proton MRI.

    Science.gov (United States)

    Miller, G Wilson; Mugler, John P; Sá, Rui C; Altes, Talissa A; Prisk, G Kim; Hopkins, Susan R

    2014-12-01

    The field of proton lung MRI is advancing on a variety of fronts. In the realm of functional imaging, it is now possible to use arterial spin labeling (ASL) and oxygen-enhanced imaging techniques to quantify regional perfusion and ventilation, respectively, in standard units of measurement. By combining these techniques into a single scan, it is also possible to quantify the local ventilation-perfusion ratio, which is the most important determinant of gas-exchange efficiency in the lung. To demonstrate potential for accurate and meaningful measurements of lung function, this technique was used to study gravitational gradients of ventilation, perfusion, and ventilation-perfusion ratio in healthy subjects, yielding quantitative results consistent with expected regional variations. Such techniques can also be applied in the time domain, providing new tools for studying temporal dynamics of lung function. Temporal ASL measurements showed increased spatial-temporal heterogeneity of pulmonary blood flow in healthy subjects exposed to hypoxia, suggesting sensitivity to active control mechanisms such as hypoxic pulmonary vasoconstriction, and illustrating that to fully examine the factors that govern lung function it is necessary to consider temporal as well as spatial variability. Further development to increase spatial coverage and improve robustness would enhance the clinical applicability of these new functional imaging tools. In the realm of structural imaging, pulse sequence techniques such as ultrashort echo-time radial k-space acquisition, ultrafast steady-state free precession, and imaging-based diaphragm triggering can be combined to overcome the significant challenges associated with proton MRI in the lung, enabling high-quality three-dimensional imaging of the whole lung in a clinically reasonable scan time. Images of healthy and cystic fibrosis subjects using these techniques demonstrate substantial promise for non-contrast pulmonary angiography and detailed

  2. ASL TALK. An Investigation of Authentic Spiritual Leadership (ASL): A Discursive Study

    OpenAIRE

    Bünger, Y.

    2011-01-01

    This study explores how a global network of people construct an idea(l) of leadership, by combining authenticity, spirituality and leadership in (con-)text of current socio-cultural movements, CSR, 'ethical profit', and stages of leadership history. The concept of a unity of authenticity, spirituality and leadership is highly controversial and has attracted considerable critical scrutiny, which makes it interesting to examine how members of this community manage their accounts of ASL. With mu...

  3. 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...

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-15

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

  6. Measurement of brain perfusion, blood volume, and blood-brain barrier permeability, using dynamic contrast-enhanced T(1)-weighted MRI at 3 tesla

    DEFF Research Database (Denmark)

    Larsson, Henrik B W; Courivaud, Frédéric; Rostrup, Egill;

    2009-01-01

    Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted...... imaging of a bolus of a paramagnetic contrast agent passing through the brain. The methods are applied in patients with brain tumors and in healthy subjects. Perfusion was estimated by model-free deconvolution using Tikhonov's method (gray matter/white matter/tumor: 72 +/- 16/30 +/- 8/56 +/- 45 mL/100 g...... on a pixel-by-pixel basis of cerebral perfusion, cerebral blood volume, and blood-brain barrier permeability....

  7. 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.)

  8. Is there any correlation between model-based perfusion parameters and model-free parameters of time-signal intensity curve on dynamic contrast enhanced MRI in breast cancer patients?

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Boram; Kang, Doo Kyoung; Kim, Tae Hee [Ajou University School of Medicine, Department of Radiology, Suwon, Gyeonggi-do (Korea, Republic of); Yoon, Dukyong [Ajou University School of Medicine, Department of Biomedical Informatics, Suwon (Korea, Republic of); Jung, Yong Sik; Kim, Ku Sang [Ajou University School of Medicine, Department of Surgery, Suwon (Korea, Republic of); Yim, Hyunee [Ajou University School of Medicine, Department of Pathology, Suwon (Korea, Republic of)

    2014-05-15

    To find out any correlation between dynamic contrast-enhanced (DCE) model-based parameters and model-free parameters, and evaluate correlations between perfusion parameters with histologic prognostic factors. Model-based parameters (Ktrans, Kep and Ve) of 102 invasive ductal carcinomas were obtained using DCE-MRI and post-processing software. Correlations between model-based and model-free parameters and between perfusion parameters and histologic prognostic factors were analysed. Mean Kep was significantly higher in cancers showing initial rapid enhancement (P = 0.002) and a delayed washout pattern (P = 0.001). Ve was significantly lower in cancers showing a delayed washout pattern (P = 0.015). Kep significantly correlated with time to peak enhancement (TTP) (ρ = -0.33, P < 0.001) and washout slope (ρ = 0.39, P = 0.002). Ve was significantly correlated with TTP (ρ = 0.33, P = 0.002). Mean Kep was higher in tumours with high nuclear grade (P = 0.017). Mean Ve was lower in tumours with high histologic grade (P = 0.005) and in tumours with negative oestrogen receptor status (P = 0.047). TTP was shorter in tumours with negative oestrogen receptor status (P = 0.037). We could acquire general information about the tumour vascular physiology, interstitial space volume and pathologic prognostic factors by analyzing time-signal intensity curve without a complicated acquisition process for the model-based parameters. (orig.)

  9. Perfusion Quantification Using Gaussian Process Deconvolution

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke; Have, Anna Szynkowiak; Rasmussen, Carl Edward;

    2002-01-01

    The quantification of perfusion using dynamic susceptibility contrast MRI (DSC-MRI) requires deconvolution to obtain the residual impulse response function (IRF). In this work, a method using the Gaussian process for deconvolution (GPD) is proposed. The fact that the IRF is smooth is incorporated...

  10. Simultaneous perception of a spoken and a signed language: The brain basis of ASL-English code-blends.

    Science.gov (United States)

    Weisberg, Jill; McCullough, Stephen; Emmorey, Karen

    2015-08-01

    Code-blends (simultaneous words and signs) are a unique characteristic of bimodal bilingual communication. Using fMRI, we investigated code-blend comprehension in hearing native ASL-English bilinguals who made a semantic decision (edible?) about signs, audiovisual words, and semantically equivalent code-blends. English and ASL recruited a similar fronto-temporal network with expected modality differences: stronger activation for English in auditory regions of bilateral superior temporal cortex, and stronger activation for ASL in bilateral occipitotemporal visual regions and left parietal cortex. Code-blend comprehension elicited activity in a combination of these regions, and no cognitive control regions were additionally recruited. Furthermore, code-blends elicited reduced activation relative to ASL presented alone in bilateral prefrontal and visual extrastriate cortices, and relative to English alone in auditory association cortex. Consistent with behavioral facilitation observed during semantic decisions, the findings suggest that redundant semantic content induces more efficient neural processing in language and sensory regions during bimodal language integration.

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

  12. Measurement of myocardial perfusion using magnetic resonance

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.;

    2008-01-01

    Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper review...... myocardial perfusion imaging with MR contrast agents: methods, validation and experiences from clinical studies. Unresolved issues still restrict the use of these techniques to research although clinical applications are within reach Udgivelsesdato: 2008/12/8......Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...

  13. Measuring myocardial perfusion

    DEFF Research Database (Denmark)

    Qayyum, A A; Kastrup, J

    2015-01-01

    -pass of non-ionic and ionic contrast agents, respectively. Absolute quantification with CMR has yet to be established in routine clinical practice, while CT has yet to prove its diagnostic and prognostic value. The upcoming years may change the way we diagnose and treat patients suspected of having CAD......Recently, focus has changed from anatomical assessment of coronary arteries towards functional testing to evaluate the effect of stenosis on the myocardium before intervention. Besides positron-emission tomography (PET), cardiac MRI (CMR), and cardiac CT are able to measure myocardial perfusion...

  14. CT perfusion imaging for patients of posterior circulation ischemia without responsible lesions on MRI scanning%MRI检查无责任病灶脑后循环缺血患者的CT灌注成像研究

    Institute of Scientific and Technical Information of China (English)

    戚观树; 侯群; 曹志坚; 李冉冉; 许茂盛

    2013-01-01

    Objective To assess the diagnostic value of CT perfusion imaging in patients of posterior circulation ischemia (PCI) without responsible lesions on MRI scanning. Methods Twenty four patients with clinical diagnosis of PCI underwent MRI DWI examination, for the patients without responsible lesions on MRI, CTPI was then performed. The region of interest (ROI ) was hand-painted and the perfusion parameters of abnormal regions and normal regions were recorded, including regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV),mean transmit time (MTT) and time to peak (TTP). Results Out of 24 cases positive CTPI was detected in 18 with a positive rate of 75%. There were 26 ischemic focuses detected, including 10 in cerebel um (38.5%), 7 in occipital lobe (26.9%), 3 in temporal lobe (11.5%) and 6 in brainstem (23.1%). Abnormal regions were detected on the diagram of TTP in 15 cases and the findings were corresponded to clinical symptoms;those were detected by rCBF in 13 cases and those detected by rCBC in 8 cases. The stages of cerebral infarction prophase included I-1 in 4 cases, I-2 in 1 case, II-1 in 5 cased and II-2 in 8 cases. Conclusion CTPI can objectively evaluate cerebral blood flow perfusion and is of value in detection of ischemic focuses that are not found by MRI scanning.%  目的探讨MRI检查显示无责任病灶的脑后循环缺血(PCI)患者的局部脑血流灌注情况,探索PCI患者早期诊断的有效方法.方法选取符合PCI临床诊断的24例患者行头颅MRI检查,对未发现责任病灶的患者进一步行CT灌注成像(CTPI)检查.在CTPI图像上手绘感兴趣区域(ROI),记录病灶区与对照区的灌注参数,包括局部脑血流量(rCBF)、局部脑血容量(rCBV)、平均通过时间(MTT)和达峰时间(TTP).结果 CTPI检查发现异常灌注18例(阳性率75%),缺血灶共26处,其中小脑10处(38.5%),枕叶7处(26.9%),颞叶3处(11.5%),脑干6处(23.1%).TTP发现异常15例,且均与临床

  15. Does amygdalar perfusion correlate with antidepressant response to partial sleep deprivation in major depression?

    OpenAIRE

    Clark, Camellia P.; Brown, Gregory G.; Archibald, Sarah L.; Fennema-Notestine, Christine; Braun, Deborah R.; Thomas, Linda S.; Sutherland, Ashley N.; Gillin, J. Christian

    2005-01-01

    This study used functional MRI (fMRI) to clarify the sites of brain activity associated with the antidepressant effects of sleep deprivation (SD). We hypothesized: (1) baseline perfusion in right and left amygdalae will be greater in responders than in nonresponders; (2) following partial sleep deprivation (PSD), perfusion in responders’ right and left amygdalae would decrease. Seventeen unmedicated outpatients with current major depression and eight controls received perfusion-weighted fMRI ...

  16. Renal perfusion scintiscan

    Science.gov (United States)

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

  17. Multimodal MRI in the characterization of glial neoplasms: the combined role of single-voxel MR spectroscopy, diffusion imaging and echo-planar perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zonari, Paolo [Ospedale ' ' B. Ramazzini' ' , AUSL Modena, Neuroradiologia, Dipartimento Integrato di Neuroscienze, Carpi, Modena (Italy); Baraldi, Patrizia [Universita degli Studi di Modena e Reggio Emilia, Dipartimento di Scienze Biomediche, Sezione di Fisiologia, Modena (Italy); Crisi, Girolamo [Azienda Ospedaliero-Universitaria di Parma, Dipartimento ad Attivita Integrata di Neuroscienze, Parma (Italy)

    2007-10-15

    Diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI) and MR spectroscopy (MRS) provide useful data for tumor evaluation. To assess the contribution of these multimodal techniques in grading glial neoplasms, we compared the value of DWI, PWI and MRS in the evaluation of histologically proven high- and low-grade gliomas in a population of 105 patients. Independently for each modality, the following variables were used to compare the tumors: minimum apparent diffusion coefficient (ADC) and maximum relative cerebral blood volume (rCBV) normalized values between tumor and healthy tissue, maximum Cho/Cr ratio and minimum NAA/Cr ratio in tumor, and scored lactate and lipid values in tumor. The Mann-Whitney and Wilcoxon tests were employed to compare DWI, PWI and MRS between tumor types. Logistic regression analysis was used to determine which parameters best increased the diagnostic accuracy in terms of sensitivity, specificity, and positive and negative predictive values. ROC curves were determined for parameters with high sensitivity and specificity to identify threshold values to separate high- from low-grade lesions. Statistically significant differences were found for rCBV tumor/normal tissue ratio, and NAA/Cr ratio in tumor and Cho/Cr ratio in tumor between low- and high-grade tumors. The best performing single parameter for group classification was the normalized rCBV value; including all parameters, statistical significance was reached by rCBV tumor/normal tissue ratio, NAA/Cr tumor ratio and lactate. From the ROC curves, a high probability for a neoplasm to be a high-grade lesion was associated with a rCBV tumor/normal tissue ratio of >1.16 and NAA/Cr tumor ratio of <0.44. Combining PWI and MRS with conventional MR imaging increases the accuracy of the attribution of malignancy to glial neoplasms. The best performing parameter was found to be the perfusion level. (orig.)

  18. ASL: Comparison of presaturation and RF pulse optimization

    DEFF Research Database (Denmark)

    Holm, David; Sidaros, Karam

    2005-01-01

    In arterial spin labelling, the difference between the tag and control image is on the order of 1% of the equilibrium magnetization. A small offset between the images not related to perfusion, can therefore lead to large errors in the measured perfusion. One source of error is non-ideal RF pulses...

  19. 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.

  20. Improved ASL based Gesture Recognition using HMM for System Application

    Directory of Open Access Journals (Sweden)

    Shalini Anand

    2014-03-01

    Full Text Available Gesture recognition is a growing field of research and among various human computer interactions; hand gesture recognition is very popular for interacting between human and machines. It is non verbal way of communication and this research area is full of innovative approaches. This project aims at recognizing 34 basic static hand gestures based on American Sign Language (ASL including alphabets as well as numbers (0 to 9. In this project we have not considered two alphabets i.e J and Z as our project aims as recognizing static hand gesture but according to ASL they are considered as dynamic. The main features used are optimization of the database using neural network and Hidden Markov Model (HMM. That is the algorithm is based on shape based features by keeping in the mind that shape of human hand is same for all human beings except in some situations

  1. 3D - ASL 脑灌注成像在脑胶质瘤分级中的应用%Application of 3D - ASL Imaging in brain glioma grading

    Institute of Scientific and Technical Information of China (English)

    田维; 高帅

    2016-01-01

    目的:探讨3D 动脉自旋标记成像( ASL)全脑灌注成像技术在脑胶质瘤分级中的应用价值。方法:对25例经手术病理证实的低级别脑胶质瘤(Ⅰ~Ⅱ级,9例),高级别脑胶质瘤(Ⅲ~Ⅳ级,16例)行3D - ASL 脑灌注成像扫描,测量各级别脑胶质瘤的脑血流量( CBF)及相对脑血流量(rCBF 白质和 rCBF 灰质),并评价它们间的差异性。结果:高级别脑胶质瘤的 CBF 及 rCBF 白质、rCBF 灰质均大于低级别胶质瘤,差异具有统计学意义(P ﹤0.001)。结论:3D - ASL 脑灌注成像技术在评价脑胶质瘤的分级中具有重要应用价值。%Objective:To explore the clinical value of three dimensional( 3D)whole brain arterial spin labeling( ASL)technique in brain glioma grad-ing. Methods:25 patients with brain glioma,were scheduled and diagnosed by pathology,including 9 Low - grade gliomas(Ⅰ ~ Ⅱgrade)and 16 High - grade gliomas(Ⅲ ~ Ⅳgrade),were underwent 3D - ASL perfusion imaging scan. The cerebral blood flow of each grade gliomas( CBF)and the relative cerebral blood flow of contralateral white matter(rCBFwhite)and the relative cerebral blood flow of contralateral grey matter(rCBFgrey)were measured. Results:Differences in High - grade gliomas and Low - grade gliomas were found,and the CBF、rCBFwhite and rCBFgrey in High - grade gliomas were higher than that in Low - grade gliomas(P ﹤ 0. 001). Conclusions:3D - ASL imaging technique is of great value in brain glioma grading.

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

    Institute of Scientific and Technical Information of China (English)

    谢晟; 齐朝月; 肖江喜; 杨艳玲; 蒋学祥

    2008-01-01

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

  3. Evaluation of tumor blood flow after feeder embolization in meningiomas by arterial spin-labeling perfusion magnetic resonance imaging.

    Science.gov (United States)

    Kawaji, Hiroshi; Koizumi, Shinichiro; Sakai, Naoto; Yamasaki, Tomohiro; Hiramatsu, Hisaya; Kanoko, Yusuke; Kamiya, Mika; Yamashita, Shuhei; Takehara, Yasuo; Sakahara, Harumi; Namba, Hiroki

    2013-10-01

    Preoperative embolization changes the amount of blood flow and pattern of flow distribution in meningioma. Tumor blood flow was investigated in eight meningioma patients before and after embolization using arterial spin-labeling (ASL) perfusion imaging. Although blood flow was significantly reduced in the whole tumor after embolization, changes in flow distribution patterns varied from one case to another. The findings suggest that evaluation of post-embolization tumor blood flow by ASL perfusion imaging would be useful in the surgical planning of meningioma.

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

    DEFF Research Database (Denmark)

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

    2006-01-01

    Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term-born neon......Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term...

  5. Hyperemic flow heterogeneity within the calf, foot, and forearm measured with continuous arterial spin labeling MRI

    OpenAIRE

    Wu, Wen-Chau; Wang, Jiongjiong; Detre, John A.; Wehrli, Felix W.; Mohler, Emile; Ratcliffe, Sarah J.; Floyd, Thomas F

    2008-01-01

    Arterial spin labeling (ASL) is a noninvasive magnetic resonance imaging (MRI) technique for microvascular blood flow measurement. We used a continuous ASL scheme (CASL) to investigate the hyperemic flow difference between major muscle groups in human extremities. Twenty-four healthy subjects with no evidence of vascular disease were recruited. MRI was conducted on a 3.0 Tesla Siemens Trio whole body system with a transmit/receive knee coil. A nonmagnetic orthopedic tourniquet system was used...

  6. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  7. 'And' or 'or': General use coordination in ASL

    Directory of Open Access Journals (Sweden)

    Kathryn Davidson

    2013-08-01

    Full Text Available In American Sign Language (ASL, conjunction (‘and’ and disjunction (‘or’ are often conveyed by the same general use coordinator (transcribed as “COORD”. So the sequence of signs MARY WANT TEA COORD COFFEE can be interpreted as ‘Mary wants tea or coffee’ or ‘Mary wants tea and coffee’ depending on contextual, prosodic, or other lexical cues. This paper takes the first steps in describing the syntax and semantics of two general use coordinators in ASL, finding that they have a similar syntactic distribution to English coordinators and and or. Semantically, arguments are made against an ambiguity approach to account for the conjunctive and disjunctive readings; instead, I propose a Hamblin-style alternative semantics where the disjunctive and conjunctive force comes from external quantification over a set of alternatives. The pragmatic consequences of using only a prosodic distinction between disjunction from conjunction is examined via a felicity judgement study of scalar implicatures. Results indicate decreased scalar implicatures when COORD is used as disjunction, supporting the semantic analysis and suggesting that the contrast of lexical items in the scale plays an important role in its pragmatics. Extensions to other languages with potential general use coordination are discussed. http://dx.doi.org/10.3765/sp.6.4 BibTeX info

  8. Associations between muscle perfusion and symptoms in knee osteoarthritis

    DEFF Research Database (Denmark)

    Bandak, E; Boesen, M; Bliddal, H;

    2015-01-01

    OBJECTIVE: To investigate the association between muscle perfusion in the peri-articular knee muscles assessed by dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and symptoms in patients with knee osteoarthritis (KOA). DESIGN: In a cross-sectional setting, muscle perfusion......-MRI and clinical data were analyzed in 94 patients. The typical participant was a woman with a mean age of 65 years, and a body mass index (BMI) of 32 kg/m(2). Reduced multiple regression models analyzing the association between KOOS and DCE-MRI perfusion variables of Total Muscle Volume showed a statistically...... significant association between Nvoxel% and KOOS pain (0.41 (SE 0.14); P = 0.0048). Nvoxel% was defined as the proportion of highly perfused voxels; i.e., the voxels that show an early and rapid increase on the signal intensity vs time curves, reach a plateau state (plateau pattern) and then showing...

  9. Simultaneous Multiagent Hyperpolarized 13C Perfusion Imaging

    DEFF Research Database (Denmark)

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

    2014-01-01

    Purpose: To demonstrate simultaneous hyperpolarization and imaging of three 13C-labeled perfusion MRI contrast agents with dissimilar molecular structures ([13C]urea, [13C]hydroxymethyl cyclopropane, and [13C]t-butanol) and correspondingly variable chemical shifts and physiological characteristics...... in simulations. "Tripolarized" perfusion MRI methods were applied to initial preclinical studies with differential conditions of vascular permeability, in normal mouse tissues and advanced transgenic mouse prostate tumors. Results: Dynamic imaging revealed clear differences among the individual tracer...... distributions. Computed permeability maps demonstrated differential permeability of brain tissue among the tracers, and tumor perfusion and permeability were both elevated over values expected for normal tissues. Conclusion: Tripolarized perfusion MRI provides new molecular imaging measures for specifically...

  10. 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

  11. State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Viallon, Magalie [Universite de Lyon, CREATIS, UMR CNRS 5220 - INSERM U1044, INSA de Lyon, Lyon (France); Universite de Lyon-Saint-Etienne, Department of Radiology, Centre Hospitalier Universitaire de Saint-Etienne, Saint Etienne (France); Cuvinciuc, Victor; Barnaure-Nachbar, Isabelle; Lovblad, Karl-Olof; Haller, Sven [University Hospital of Geneva, Department of Neuroradiology, Geneva (Switzerland); Delattre, Benedicte; Toso-Patel, Seema; Becker, Minerva [University Hospital of Geneva, Department of Radiology, Geneva (Switzerland); Merlini, Laura [University Hospital of Geneva, Department of Pediatric Radiology, Geneva (Switzerland)

    2015-05-01

    This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional (3D) techniques in neuro MRI, including state-of-the-art and emerging angiography sequences, and briefly introduce more recently proposed 3D quantitative neuro-anatomy sequences, and new technology, such as multi-slice and multi-transmit imaging. (orig.)

  12. State-of-the-art MRI techniques in neuroradiology: principles, pitfalls, and clinical applications

    International Nuclear Information System (INIS)

    This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods. The technical requirements and how they may help to understand, classify, or follow-up neurological pathologies are briefly summarized. Techniques, principles, advantages but also intrinsic limitations, typical artifacts, and alternative solutions developed to overcome them are discussed. In this article, we also review routinely available three-dimensional (3D) techniques in neuro MRI, including state-of-the-art and emerging angiography sequences, and briefly introduce more recently proposed 3D quantitative neuro-anatomy sequences, and new technology, such as multi-slice and multi-transmit imaging. (orig.)

  13. Improving perfusion quantification in arterial spin labeling for delayed arrival times by using optimized acquisition schemes

    Energy Technology Data Exchange (ETDEWEB)

    Kramme, Johanna [Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen (Germany); Univ. Bremen (Germany). Faculty of Physics and Electronics; Gregori, Johannes [mediri GmbH, Heidelberg (Germany); Diehl, Volker [Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen (Germany); ZEMODI (Zentrum fuer morderne Diagnostik), Bremen (Germany); Madai, Vince I.; Sobesky, Jan [Charite-Universitaetsmedizin Berlin (Germany). Center for Stroke Research Berlin (CSB); Charite-Universitaetsmedizin Berlin (Germany). Dept. of Neurology; Samson-Himmelstjerna, Frederico C. von [Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen (Germany); Charite-Universitaetsmedizin Berlin (Germany). Center for Stroke Research Berlin (CSB); Charite-Universitaetsmedizin Berlin (Germany). Dept. of Neurology; Lentschig, Markus [ZEMODI (Zentrum fuer morderne Diagnostik), Bremen (Germany); Guenther, Matthias [Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen (Germany); Univ. Bremen (Germany). Faculty of Physics and Electronics; mediri GmbH, Heidelberg (Germany)

    2015-07-01

    The improvement in Arterial Spin Labeling (ASL) perfusion quantification, especially for delayed bolus arrival times (BAT), with an acquisition redistribution scheme mitigating the T1 decay of the label in multi-TI ASL measurements is investigated. A multi inflow time (TI) 3D-GRASE sequence is presented which adapts the distribution of acquisitions accordingly, by keeping the scan time constant. The MR sequence increases the number of averages at long TIs and decreases their number at short TIs and thus compensating the T1 decay of the label. The improvement of perfusion quantification is evaluated in simulations as well as in-vivo in healthy volunteers and patients with prolonged BATs due to age or steno-occlusive disease. The improvement in perfusion quantification depends on BAT. At healthy BATs the differences are small, but become larger for longer BATs typically found in certain diseases. The relative error of perfusion is improved up to 30% at BATs > 1500 ms in comparison to the standard acquisition scheme. This adapted acquisition scheme improves the perfusion measurement in comparison to standard multi-TI ASL implementations. It provides relevant benefit in clinical conditions that cause prolonged BATs and is therefore of high clinical relevance for neuroimaging of steno-occlusive diseases.

  14. Utility of susceptibility-weighted imaging and arterial spin perfusion imaging in pediatric brain arteriovenous shunting

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, Seyed Ali; Edgar, J.C.; Vossough, Arastoo [University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2014-10-15

    The objectives of the study are to investigate the application of susceptibility-weighted imaging (SWI) and arterial spin labeling (ASL) imaging in the assessment of shunting and the draining veins in pediatric patients with arteriovenous shunting and compare the utility of SWI and ASL with conventional MR and digital subtraction angiography (DSA). This study is a retrospective study of 19 pediatric patients with arteriovenous shunting on brain MRI who were also evaluated with DSA. We assessed the ability of conventional MRI sequences, susceptibility magnitude images, phase-filtered SWI images, and pulsed ASL images in the detection of arteriovenous (AV) shunting, number of draining veins and drainage pathways in comparison to DSA. The mean number of detected draining veins on DSA (3.63) was significantly higher compared to SWI phase-filtered image (mean = 2.72), susceptibility magnitude image (mean = 2.92), ASL (mean = 1.76) and conventional MRI (2.47) (p < 0.05). Pairwise comparison of DSA difference scores (i.e., difference between MR modalities in the number of missed draining veins) revealed no difference between the MR modalities (p > 0.05). ASL was the only method that correctly identified superficial and deep venous drainage in all patients. Regarding detection of shunting, ASL, SWI phase-filtered, and magnitude images demonstrated shunting in 100, 83, and 84 % of patients, respectively. SWI depicts a higher number of draining vein compared to conventional MR pulse sequences. ASL is a sensitive approach in showing 100 % sensitivity in the detection of AV shunting and in the diagnosis of the pattern of venous drainage. The present findings suggest the added utility of both SWI and ASL in the assessment of AV shunting. (orig.)

  15. Amygdala perfusion is predicted by its functional connectivity with the ventromedial prefrontal cortex and negative affect.

    Directory of Open Access Journals (Sweden)

    Garth Coombs

    Full Text Available BACKGROUND: Previous studies have shown that the activity of the amygdala is elevated in people experiencing clinical and subclinical levels of anxiety and depression (negative affect. It has been proposed that a reduction in inhibitory input to the amygdala from the prefrontal cortex and resultant over-activity of the amygdala underlies this association. Prior studies have found relationships between negative affect and 1 amygdala over-activity and 2 reduced amygdala-prefrontal connectivity. However, it is not known whether elevated amygdala activity is associated with decreased amygdala-prefrontal connectivity during negative affect states. METHODS: Here we used resting-state arterial spin labeling (ASL and blood oxygenation level dependent (BOLD functional magnetic resonance imaging (fMRI in combination to test this model, measuring the activity (regional cerebral blood flow, rCBF and functional connectivity (correlated fluctuations in the BOLD signal of one subregion of the amygdala with strong connections with the prefrontal cortex, the basolateral nucleus (BLA, and subsyndromal anxiety levels in 38 healthy subjects. RESULTS: BLA rCBF was strongly correlated with anxiety levels. Moreover, both BLA rCBF and anxiety were inversely correlated with the strength of the functional coupling of the BLA with the caudal ventromedial prefrontal cortex. Lastly, BLA perfusion was found to be a mediator of the relationship between BLA-prefrontal connectivity and anxiety. CONCLUSIONS: These results show that both perfusion of the BLA and a measure of its functional coupling with the prefrontal cortex directly index anxiety levels in healthy subjects, and that low BLA-prefrontal connectivity may lead to increased BLA activity and resulting anxiety. Thus, these data provide key evidence for an often-cited circuitry model of negative affect, using a novel, multi-modal imaging approach.

  16. Foreword: Advanced Science Letters (ASL), Special Issue on Computational Astrophysics

    CERN Document Server

    ,

    2009-01-01

    Computational astrophysics has undergone unprecedented development over the last decade, becoming a field of its own. The challenge ahead of us will involve increasingly complex multi-scale simulations. These will bridge the gap between areas of astrophysics such as star and planet formation, or star formation and galaxy formation, that have evolved separately until today. A global knowledge of the physics and modeling techniques of astrophysical simulations is thus an important asset for the next generation of modelers. With the aim at fostering such a global approach, we present the Special Issue on Computational Astrophysics for the Advanced Science Letters (http://www.aspbs.com/science.htm). The Advanced Science Letters (ASL) is a new multi-disciplinary scientific journal which will cover extensively computational astrophysics and cosmology, and will act as a forum for the presentation and discussion of novel work attempting to connect different research areas. This Special Issue collects 9 reviews on 9 k...

  17. Perfusion harmonic imaging of the human brain

    Science.gov (United States)

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

    2003-05-01

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

  18. Whole-brain perfusion imaging with balanced steady-state free precession arterial spin labeling.

    Science.gov (United States)

    Han, Paul Kyu; Ye, Jong Chul; Kim, Eung Yeop; Choi, Seung Hong; Park, Sung-Hong

    2016-03-01

    Recently, balanced steady-state free precession (bSSFP) readout has been proposed for arterial spin labeling (ASL) perfusion imaging to reduce susceptibility artifacts at a relatively high spatial resolution and signal-to-noise ratio (SNR). However, the main limitation of bSSFP-ASL is the low spatial coverage. In this work, methods to increase the spatial coverage of bSSFP-ASL are proposed for distortion-free, high-resolution, whole-brain perfusion imaging. Three strategies of (i) segmentation, (ii) compressed sensing (CS) and (iii) a hybrid approach combining the two methods were tested to increase the spatial coverage of pseudo-continuous ASL (pCASL) with three-dimensional bSSFP readout. The spatial coverage was increased by factors of two, four and six using each of the three approaches, whilst maintaining the same total scan time (5.3 min). The number of segments and/or CS acceleration rate (R) correspondingly increased to maintain the same bSSFP readout time (1.2 s). The segmentation approach allowed whole-brain perfusion imaging for pCASL-bSSFP with no penalty in SNR and/or total scan time. The CS approach increased the spatial coverage of pCASL-bSSFP whilst maintaining the temporal resolution, with minimal impact on the image quality. The hybrid approach provided compromised effects between the two methods. Balanced SSFP-based ASL allows the acquisition of perfusion images with wide spatial coverage, high spatial resolution and SNR, and reduced susceptibility artifacts, and thus may become a good choice for clinical and neurological studies. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

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

  20. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

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

  1. Application of multi modal magnetic resonance perfusion technique in acute ischemic stroke pateints with blood perfusion in the diagnosis%多模式磁共振灌注技术在急性缺血性脑梗死患者脑血流灌注状态诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    郝敬波; 鹿彩銮; 时宏娟; 杨荣礼; 徐凯; 董瑞国

    2015-01-01

    Objective To analyze the cerebral blood flow perfusion status diagnosis in ischemic stroke patients by three-dimension arterial spin labeling imaging ( 3D-ASL ) and dynamic susceptibility contrast enhanced perfusion(DSC-PWI ).Methods Routine MRI with DWI, MRA,3D-ASL and DSC-PWI scan were performed in 22 patients with ischemic stroke.Observation of patients with cerebral infarction 3DA-SL and DSC-PWI perfusion image processing and score ( showed hyperperfusion is denoted by +1, no vision recorded as 0, hypoperfusion denoted as-1) , and a comparative analysis of the differences between ASL -CBF and PWI in measurement of CBF,CBV, MTT andTmax.Results 22patientsofASLperfusionabnormalin19cases(86.3%),PWI-CBF,PWI-CBV,andPWI-Tmax PWI-MTT abnormal respectively for 14 patients (63.6%), 12 patients (54.5%), 14 patients (63.6%) and 16 patients (72.7%).The MC nemar test results showed that ASL and PWI-CBF, PWI-CBV parameters in patients showed perfusion differences had statistical significance (P=0.025, 0.008, respectively).Remove display cases of hypererfusion, ASL-CBF and PWI parameters P were 0.125 ,0.031, 0.125, 0.250, where differences in CBF, MTT and Tmax no statistical significance ( P<0.05) .Con clusion As a noninvasive technique, ASL can basically in clinical application is reliable to reflect the hypoperfusion in patients with ischemic cerebral infarction.%目的:分析磁共振三维动脉自旋标记成像(3D-ASL )与动态磁敏感对比增强灌注成像(DSC-PWI)在急性缺血性脑梗死患者脑血流灌注状态诊断中的应用。方法22例缺血性脑梗死患者行常规MRI序列、DWI、MRA、3D-ASL及DSC-PWI检查。观察脑梗死患者的3D-ASL、DSC-PWI灌注后处理图像并进行评分(显示有高灌注记为+1,未见明显灌注异常记为0,低灌注记为-1),并比较分析ASL-CBF 与PWI测量的CBF、CBV、MTT及Tmax之间的差异。结果22例中ASL显示灌注异常者有19例(86.3

  2. 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.

  3. 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

  4. Perfusion CT in childhood stroke—Initial observations and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Zebedin, D., E-mail: doris.zebedin@medunigraz.at [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria); Sorantin, E.; Riccabona, M. [Division of Pediatric Radiology, Department of Radiology, University Hospital LKH Graz (Austria)

    2013-07-15

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction.

  5. Perfusion CT in childhood stroke—Initial observations and review of the literature

    International Nuclear Information System (INIS)

    Introduction: To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke. Patients and methods: Within the last two years emergency perfusion CT was performed in ten children (age: 8–17 years, male:female = 3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts. Results: In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy. Conclusions: In comparison to standard CT, contrast-enhanced perfusion CT improves CTs’ diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction

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

    Institute of Scientific and Technical Information of China (English)

    崔恒; 程敬亮; 张勇

    2012-01-01

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

  7. Ventilation-perfusion scintigraphy

    International Nuclear Information System (INIS)

    A historical review of different investigation methods measuring lung function (perfusion and gas exchange) is given. The principles and handling of some ventilation methods using radioxenon, radiokrypton or radiolabelled aerosols, and the injection method of xenon are explained. The clinical applicability of these studies is evaluated considering ventilation and perfusion lung defects and congestive heart failure. The combination of the three principal techniques (perfusion scintigraphy using MAA, ventilation scintigraphy using radioxenon or radiokrypton, perfusion and ventilation scientigraphy after injection of radioxenon) lead to typical patterns of differential diagnosis of perfusion defects. (TRV)

  8. First experiences with contrast-enhanced first-pass MR perfusion imaging in patients with primary, benign cardiac masses and tumour-like lesions

    Energy Technology Data Exchange (ETDEWEB)

    Mohrs, Oliver K. [Darmstadt Radiology, Department of Cardiovascular Imaging at Alice-Hospital, Darmstadt (Germany); German Cancer Research Center (DKFZ), Department of Radiology, Heidelberg (Germany); Voigtlaender, Thomas [Cardiovascular Center Bethanien (CCB), Frankfurt/Main (Germany); Petersen, Steffen E. [John Radcliffe Hospital, University of Oxford, OCMR, Oxford (United Kingdom); Zander, Matthias [Darmstadt Center of Cardiology, Darmstadt (Germany); Schulze, Thomas [Siemens Medical Solutions, Frankfurt/Main (Germany); Pottmeyer, Anselm [Darmstadt Radiology, Department of Cardiovascular Imaging at Alice-Hospital, Darmstadt (Germany); Kauczor, Hans-Ulrich [German Cancer Research Center (DKFZ), Department of Radiology, Heidelberg (Germany)

    2008-08-15

    The aim of this study was to evaluate the diagnostic value of contrast-enhanced first-pass perfusion MRI in patients with suspected cardiac masses and tumour-like lesions. Twenty patients underwent contrast-enhanced first-pass saturation-recovery steady-state-free-precession perfusion MRI in addition to clinical MRI. Eleven diagnostic parameters were analysed blinded in consensus by three observers: localisation (paracardiac/mural/intracavitary), malignancy (benign/malignant) and first-pass enhancement pattern (homogeneous/heterogeneous as well as non-perfused/hypoperfused/iso-perfused/ hyperperfused). The results were compared to combined references comprising histology, cytology, medical and surgical reports, echocardiography, chest X-ray, coronary angiography and regular MRI. Also, we analysed if additional first-pass perfusion confirmed, changed or reduced the number of differential diagnoses compared to clinical MRI. All cardiac masses or tumour-like lesions were correctly localised and scored as benign lesions. For homogeneous perfused lesions the sensitivity, specificity, positive and negative predictive value was 94/100/100/67%, 100/94/67/100% for heterogeneous perfused lesions, 92/100/100/88% for non-perfused, 100/94/75/100 for hypoperfused, 100/100/100/100% for hyperperfused and for isoperfused lesions. In 17/2/1 cases perfusion MRI confirmed, reduced or increased the number of potential differentials. First-pass perfusion MRI provides valuable information in patients with benign cardiac masses or tumour-like lesions. Further experience is needed to underline these preliminary observations. (orig.)

  9. 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.)

  10. Perfusion CT in acute stroke; Stellenwert der CT-Perfusion fuer die Therapie des Schlaganfalls

    Energy Technology Data Exchange (ETDEWEB)

    Eckert, Bernd [Asklepios Klinik Altona (Germany). Radiologie und Neuroradiologie; Roether, Joachim [Asklepios Klinik Altona (Germany). Neurologische Abt.; Fiehler, Jens [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neuroradiologische Diagnostik und Intervention; Thomalla, Goetz [Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany). Klinik und Poliklinik fuer Neurologie, Kopf- und Neurozentrum

    2015-06-15

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  11. Evaluation of Cervical Cancer Microcirculation with Duantitative Parameters and Perfusion parameters of MRI Quantitative Dynamic Contrast Enhanced Imaging%定量MRI动态增强成像定量参数和灌注参数在宫颈癌微循环评价的价值

    Institute of Scientific and Technical Information of China (English)

    孙俊旗; 吴光耀; 单菲菲; 杨昊; 王科

    2016-01-01

    Objective To evaluate cervical microcirculation with quantitative parameters and perfusion parameters of quantita -tive dynamic contrast-enhanced MRI imaging .Methods Routine MRI sequences and quantitative dynamic contrast -enhanced MRI imaging were made in 30 cases of cervical cancer ,20 cases of uterine fibroids group ,22 cases of normal cervical group .MRI image is processed using third-party software to obtain quantitative parameters ( Ktrans、Ve、Vp) and perfusion parameters ( BV、BF、MTT) .Be-tween groups and within the group of statistical analysis were performed ,ROC curve was drawn ,the threshold value and the diagnostic efficacy were determined .Results Ktrans ,Kep ,BF and BV values of quantitative dynamic contrast -enhanced MRI imaging were statis-tical difference between cervical cancer ,uterine fibroids group,normal cervical group( P<0.05).Ktrans and Kep values were significantly statistical difference between cervical cancer group and uterine fibroids group ( P<0.01).Ktrans,Kep,BF and BV values were statistical difference between cervical cancer group and normal cervical group ( P<0.05).Vp value was statistical different between normal cer-vical and uterine fibroids group ( P<0.05).No significant difference in Ve and MTT between and within group .ROC curve showed that Ktrans value was the maximum under ROC curve and its threshold value was the highest diagnostic efficacy .Conclusion Quanti-tative dynamic contrast -enhanced of MRI imaging can be quantitative diagnosis and differential diagnosis of benign and malignant le -sions of the cervix ,and show the tumor microcirculation and perfusion information .%目的:探讨MRI定量动态增强成像的定量参数及灌注参数评价宫颈癌微循环变化的价值。方法30例宫颈癌组、20例子宫肌瘤组、22例正常宫颈组进行MRI常规序列及定量动态增强成像序列成像,通过第三方软件后处理得到定量参数(Ktrans、Kep、Ve)和灌注参数(BV、BF、MTT

  12. Academic Achievement of Deaf and Hard-of-Hearing Students in an ASL/English Bilingual Program

    Science.gov (United States)

    Hrastinski, Iva; Wilbur, Ronnie B.

    2016-01-01

    There has been a scarcity of studies exploring the influence of students' American Sign Language (ASL) proficiency on their academic achievement in ASL/English bilingual programs. The aim of this study was to determine the effects of ASL proficiency on reading comprehension skills and academic achievement of 85 deaf or hard-of-hearing signing…

  13. 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

  14. Non-contrast-enhanced preoperative assessment of lung perfusion in patients with non-small-cell lung cancer using Fourier decomposition magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Gregor, E-mail: gregor.sommer@usb.ch [Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Petersgraben 4, 4031 Basel (Switzerland); Bauman, Grzegorz, E-mail: gbauman@wisc.edu [Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Department of Medical Physics in Radiology (E020), German Cancer Research Center (DKFZ), Heidelberg (Germany); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, 1111 Highland Avenue, Madison, 53705 WI (United States); Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br [Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Department of Radiology, University Hospital of the School of Medicine of Ribeirao Preto – University of Sao Paulo, Ribeirao Preto (Brazil); Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik Heidelberg gGmbH, Amalienstr. 5, 69126 Heidelberg (Germany); Draenkow, Christopher, E-mail: c.draenkow@thoraxklinik-heidelberg.de [Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Department of Surgery, Thoraxklinik Heidelberg gGmbH, Amalienstr. 5, 69126 Heidelberg (Germany); Heussel, Claus Peter, E-mail: heussel@uni-heidelberg.de [Translational Lung Research Center Heidelberg (TLRC-H), Member of the German Center for Lung Research, Heidelberg (Germany); Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik Heidelberg gGmbH, Amalienstr. 5, 69126 Heidelberg (Germany); and others

    2013-12-01

    Objective: To investigate non-contrast-enhanced Fourier decomposition MRI (FD MRI) for assessment of regional lung perfusion in patients with Non-Small-Cell Lung Cancer (NSCLC) in comparison to dynamic contrast-enhanced MRI (DCE MRI). Methods: Time-resolved non-contrast-enhanced images of the lungs were acquired prospectively in 15 patients using a 2D balanced steady-state free precession (b-SSFP) sequence. After non-rigid registration of the native image data, perfusion-weighted images were calculated by separating periodic changes of lung proton density at the cardiac frequency using FD. DCE MRI subtraction datasets were acquired as standard of reference. Both datasets were analyzed visually for perfusion defects. Then segmentation analyses were performed to describe perfusion of pulmonary lobes semi-quantitatively as percentages of total lung perfusion. Overall FD MRI perfusion signal was compared to velocity-encoded flow measurements in the pulmonary trunk as an additional fully quantitative reference. Results: Image quality ratings of FD MRI were significantly inferior to those of DCE MRI (P < 0.0001). Sensitivity, specificity, and accuracy of FD MRI for visual detection of perfusion defects were 84%, 92%, and 91%. Semi-quantitative evaluation of lobar perfusion provided high agreement between FD MRI and DCE MRI for both entire lungs and upper lobes, but less agreement in the lower parts of both lungs. FD perfusion signal showed high linear correlation with pulmonary arterial blood flow. Conclusion: FD MRI is a promising technique that allows for assessing regional lung perfusion in NSCLC patients without contrast media or ionizing radiation. However, for being applied in clinical routine, image quality and robustness of the technique need to be further improved.

  15. Are 2000 m asl a last frontier in hydrology?

    Science.gov (United States)

    Ranzi, R.

    2009-04-01

    In spite of several advancements in monitoring systems in the last decades our understanding of some key hydrological processes and measurements in mountain areas still remain affected by large uncertainties. Above 2000 m asl in the Alps, and at higher altitudes in other mountain ranges, precipitation measurements with raingauges are still affected by the snow/rain partitioning uncertainties and wind-induced losses. The network density is not sufficient to capture heavy localised storms triggered by orography, which sometimes induce extreme debris flow events; today, in some cases, raingauge density at high altitudes is coarser than several decades ago, when networks were installed for designing hydropower plants. Radar measurements, which can be more effective in monitoring localised storms, are disturbed by the melting layer and ground clutter. Areal snow water equivalent estimates are still based on point measurements of snow density and depth and, over complex topography, remote sensing is helping for estimating snow cover areas only, while distributed information on vertical snow profiles is still difficult to be obtained. Also micrometeorological measurements of turbulent fluxes are sparse for logistic reasons and data spatialisation needs meteorological modelling or complex geostatistical interpolation algorithms to be effective. Runoff is difficult to be measured in winter because of freezing of streamwater. These examples show how the key components of the hydrological balance, i.e. precipitation, snow storage, evapotranspiration losses and runoff at the basin scale are difficult to be estimated with the accuracy required by several challenging scientific investigations, as those concerning adaptation of forests to climate changes and resulting feedback, or the assessment of the benefit for aquatic systems derived from new environmental flow releases in mountain creeks. Some examples from recent experiments to measure, for energy-balance studies, eddy

  16. 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

  17. 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.

  18. Adenosine-stress dynamic real-time myocardial perfusion CT and adenosine-stress first-pass dual-energy myocardial perfusion CT for the assessment of acute chest pain: Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Weininger, Markus [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC (United States); Ramachandra, Ashok [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Rowe, Garrett W.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Henzler, Thomas [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2012-12-15

    Purpose: Recent innovations in CT enable the evolution from mere morphologic imaging to dynamic and functional testing. We describe our initial experience performing myocardial stress perfusion CT in a clinical population with acute chest pain. Methods and materials: Myocardial stress perfusion CT was performed on twenty consecutive patients (15 men, 5 women; mean age 65 ± 8 years) who presented with acute chest pain and were clinically referred for stress/rest SPECT and cardiac MRI. Prior to CT each patient was randomly assigned either to Group A or to Group B in a consecutive order (10 patients per group). Group A underwent adenosine-stress dynamic real-time myocardial perfusion CT using a novel “shuttle” mode on a 2nd generation dual-source CT. Group B underwent adenosine-stress first-pass dual-energy myocardial perfusion CT using the same CT scanner in dual-energy mode. Two experienced observers visually analyzed all CT perfusion studies. CT findings were compared with MRI and SPECT. Results: In Group A 149/170 myocardial segments (88%) could be evaluated. Real-time perfusion CT (versus SPECT) had 86% (84%) sensitivity, 98% (92%) specificity, 94% (88%) positive predictive value, and 96% (92%) negative predictive value in comparison with perfusion MRI for the detection of myocardial perfusion defects. In Group B all myocardial segments were available for analysis. Compared with MRI, dual-energy myocardial perfusion CT (versus SPECT) had 93% (94%) sensitivity, 99% (98%) specificity, 92% (88%) positive predictive value, and 96% (94%) negative predictive value for detecting hypoperfused myocardial segments. Conclusion: Our results suggest the clinical feasibility of myocardial perfusion CT imaging in patients with acute chest pain. Compared to MRI and SPECT both, dynamic real-time perfusion CT and first-pass dual-energy perfusion CT showed good agreement for the detection of myocardial perfusion defects.

  19. Prediction of Liver Function by Using Magnetic Resonance-based Portal Venous Perfusion Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cao Yue, E-mail: yuecao@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Wang Hesheng [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Johnson, Timothy D. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Pan, Charlie [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Hussain, Hero [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M.; Normolle, Daniel; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-01-01

    Purpose: To evaluate whether liver function can be assessed globally and spatially by using volumetric dynamic contrast-enhanced magnetic resonance imaging MRI (DCE-MRI) to potentially aid in adaptive treatment planning. Methods and Materials: Seventeen patients with intrahepatic cancer undergoing focal radiation therapy (RT) were enrolled in institution review board-approved prospective studies to obtain DCE-MRI (to measure regional perfusion) and indocyanine green (ICG) clearance rates (to measure overall liver function) prior to, during, and at 1 and 2 months after treatment. The volumetric distribution of portal venous perfusion in the whole liver was estimated for each scan. We assessed the correlation between mean portal venous perfusion in the nontumor volume of the liver and overall liver function measured by ICG before, during, and after RT. The dose response for regional portal venous perfusion to RT was determined using a linear mixed effects model. Results: There was a significant correlation between the ICG clearance rate and mean portal venous perfusion in the functioning liver parenchyma, suggesting that portal venous perfusion could be used as a surrogate for function. Reduction in regional venous perfusion 1 month after RT was predicted by the locally accumulated biologically corrected dose at the end of RT (P<.0007). Regional portal venous perfusion measured during RT was a significant predictor for regional venous perfusion assessed 1 month after RT (P<.00001). Global hypovenous perfusion pre-RT was observed in 4 patients (3 patients with hepatocellular carcinoma and cirrhosis), 3 of whom had recovered from hypoperfusion, except in the highest dose regions, post-RT. In addition, 3 patients who had normal perfusion pre-RT had marked hypervenous perfusion or reperfusion in low-dose regions post-RT. Conclusions: This study suggests that MR-based volumetric hepatic perfusion imaging may be a biomarker for spatial distribution of liver function, which

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

    Directory of Open Access Journals (Sweden)

    Niklaus eDenier

    2013-10-01

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

  1. Biological Properties and Characterization of ASL50 Protein from Aged Allium sativum Bulbs.

    Science.gov (United States)

    Kumar, Suresh; Jitendra, Kumar; Singh, Kusum; Kapoor, Vaishali; Sinha, Mou; Xess, Immaculata; Das, Satya N; Sharma, Sujata; Singh, Tej P; Dey, Sharmistha

    2015-08-01

    Allium sativum is well known for its medicinal properties. The A. sativum lectin 50 (ASL50, 50 kDa) was isolated from aged A. sativum bulbs and purified by gel filtration chromatography on Sephacryl S-200 column. Agar well diffusion assay were used to evaluate the antimicrobial activity of ASL50 against Candida species and bacteria then minimal inhibitory concentration (MIC) was determined. The lipid A binding to ASL50 was determined by surface plasmon resonance (SPR) technology with varying concentrations. Electron microscopic studies were done to see the mode of action of ASL50 on microbes. It exerted antimicrobial activity against clinical Candida isolates with a MIC of 10-40 μg/ml and clinical Pseudomonas aeruginosa isolates with a MIC of 10-80 μg/ml. The electron microscopic study illustrates that it disrupts the cell membrane of the bacteria and cell wall of fungi. It exhibited antiproliferative activity on oral carcinoma KB cells with an IC50 of 36 μg/ml after treatment for 48 h and induces the apoptosis of cancer cells by inducing 2.5-fold higher caspase enzyme activity than untreated cells. However, it has no cytotoxic effects towards HEK 293 cells as well as human erythrocytes even at higher concentration of ASL50. Biological properties of ASL50 may have its therapeutic significance in aiding infection and cancer treatments. PMID:26043852

  2. Chest MRI

    Science.gov (United States)

    Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax; Thoracic MRI ... healthy enough to filter the contrast. During the MRI, the person who operates the machine will watch ...

  3. MRI of the lung

    Energy Technology Data Exchange (ETDEWEB)

    Kauczor, Hans-Ulrich (ed.) [University Clinic Heidelberg (Germany). Diagnostic and Interventional Radiology

    2009-07-01

    For a long time, only chest X-ray and CT were used to image lung structure, while nuclear medicine was employed to assess lung function. During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation. (orig.)

  4. MRI of the lung

    International Nuclear Information System (INIS)

    For a long time, only chest X-ray and CT were used to image lung structure, while nuclear medicine was employed to assess lung function. During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation. (orig.)

  5. 基于动态增强磁共振测定大鼠股骨近端骨髓血流灌注功能及稳定性%Perfusion function of rat proximal femur bone marrow and its stability determined using dynamic contrast-enhanced MRI

    Institute of Scientific and Technical Information of China (English)

    张亚峰; 程琼; 祝勇; 刘璠

    2011-01-01

    背景:随着磁共振成像线圈的改进和新对比剂的使用,利用动态增强磁共振测定大鼠骨髓血流灌注功能已成为可能.目的:建立基于动态增强磁共振测定大鼠股骨近端骨髓血流灌注功能的方法,并观察其稳定性.方法:Wistar大鼠尾静脉注射对比剂,基于动态增强磁共振,利用1.5T全身磁共振系统采集股骨近端骨髓的时间-信号强度数据.1周后重复测量1次.通过时间-信号强度曲线计算最大增强率和增强系数.结果与结论:前后两次测量的最大增强率分别为(140.42±17.17)%和(136.57±13.87)%,增强系数分别为(3.81±0.17)%/s和(3.71±0.20)%/s,两次检测的最大增强率和增强系数差异无显著性意义.说明基于动态增强磁共振的大鼠股骨近端骨髓血流灌注功能测定方法稳定可靠.%BACKGROUND: Due to improvement of MRI surface coil and new-type contrasts, it is possible to use dynamiccontrast-enhanced MRI to measure bone marrow blood perfusion function in rats.OBJECTIVE: To explore the methodology using dynamic contrast -enhanced MRI to measure the perfusion function of ratproximal femur bone marrow and explore its reliability.METHODS: Contrast agents were injected from tail vein into Wistar rats. Dynamic contrast -enhanced MRI was measured using1.5T whole body MRI scanner. One week later, the measurement was repeated. Then, time-signal intensity curve was explored.Maximum enhancement (ME) and enhancement slope (ES) were calculated.RESULTS AND CONCLUSION: ME of test 1 and test 2 were (140.42±17.17)% and (136.57±13.87)%, respectively. ES of test 1and test 2 were (3.81±0.17)%/s and (3.71±0.20)%/sec, respectively. There was no statistically significant difference in ME andES between the two tests. The methodology explored in this study which used dynamic contrast enhanced MRI to measure theperfusion function of rat proximal femur bone marrow were reliable and repeatable.

  6. 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.

  7. 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.

  8. 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

  9. MRI and low back pain

    Science.gov (United States)

    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  10. Staging of moyamoya disease by perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo [Kyushu Univ., Fukuoka (Japan). Hospital; Matsushima, Toshio; Fukui, Masashi

    2001-04-01

    Staging of moyamoya disease, based on angiography and PET have already been established. The authors have established staging of moyamoya disease based on perfusion SPECT, that can be summarized as follows: Stage I, no abnormality is seen at rest or after acetazolamide loading; Stage II, no abnormality is seen at rest, however, a decreased response (blood flow increase rate: <15%) is seen to acetazolamide loading (a, a decreased response is seen only in the frontal lobe; b, a decreased response is seen in regions other than the frontal lobe; and c, a decreased response is seen throughout the cerebrum); Stage III, localized decrease in blood flow (blood flow decrease compared with peripheral tissue: {>=}15%) and marked decrease in response to acetazolamide (blood flow increase rate: <5%) are seen at rest. In Stage III, CT and MRI show no abnormal findings or only mild lesions of the white matter; and Stage IV, multiple decreases in blood flow are seen at rest, and CT and MRI reveal infarctions and severe atrophy at the same sites. The above staging does not require determination of cerebral blood flow, and thus it can be used in children, in whom cerebral blood flow determination is difficult. The authors performed 99m-Tc ECD perfusion SPECT in 25 patients with moyamoya disease for the staging, and compared staging based on angiography with staging based on perfusion SPECT. The results did not show a correlation between the 2 staging methods. A problem inherent in the staging of moyamoya disease based on perfusion SPECT is that the relationship between cerebral blood flow and cerebral radioactivity concentrations may differ depending on the drug used to determine cerebral blood flow. Thus, although the present staging system does not depend on any specific radioactive drug to determine cerebral blood flow, further investigation is necessary to identify a more appropriate drug than those in current use. (K.H.)

  11. Perfusion Linearity and Its Applications

    CERN Document Server

    Pianykh, Oleg

    2010-01-01

    Perfusion analysis computes blood flow parameters (blood volume, blood flow, mean transit time) from the observed flow of contrast agent, passing through the patient's vascular system. Perfusion deconvolution has been widely accepted as the principal numerical tool for perfusion analysis, and is used routinely in clinical applications. This extensive use of perfusion in clinical decision-making makes numerical stability and robustness of perfusion computations vital for accurate diagnostics and patient safety. The main goal of this paper is to propose a novel approach for validating numerical properties of perfusion algorithms. The approach is based on Perfusion Linearity Property (PLP), which we find in perfusion deconvolution, as well as in many other perfusion techniques. PLP allows one to study perfusion values as weighted averages of the original imaging data. This, in turn, uncovers hidden problems with the existing deconvolution techniques, and may be used to suggest more reliable computational approac...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-15

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

  13. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

  14. Evaluation of heart perfusion in patients with acute myocardial infarction using dynamic contrast-enhanced magnetic resonance imaging

    DEFF Research Database (Denmark)

    Hansen, Thomas Fritz; Dirks, Christina G; Jensen, Gorm B;

    2004-01-01

    with acute transmural myocardial infarction were studied using a Turbo-fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five......PURPOSE: To investigate the diagnostic ability of quantitative magnetic resonance imaging (MRI) heart perfusion in acute heart patients, a fast, multislice dynamic contrast-enhanced MRI sequence was applied to patients with acute myocardial infarction. MATERIALS AND METHODS: Seven patients...... was clearly beneficial in one case, but had no effect in the two other cases. Over the time-course of the study, normal perfusion values were not reestablished following thrombolytic treatment in all cases investigated. CONCLUSION: This study shows that quantitative MRI perfusion values can be obtained from...

  15. Combined MR Proton Lung Perfusion/Angiography and Helium Ventilation: Potential for Detecting Pulmonary Emboli and Ventilation Defects

    OpenAIRE

    Zheng, Jie; Leawoods, Jason C.; Nolte, Mark; Yablonskiy, Dmitriy A.; Woodard, Pamela K; Laub, Gerhardt; Gropler, Robert J.; Conradi, Mark S.

    2002-01-01

    Three-dimensional (3D) perfusion imaging allows the assessment of pulmonary blood flow in parenchyma and main pulmonary arteries simultaneously. MRI using laser-polarized 3He gas clearly shows the ventilation distribution with high signal-to-noise ratio (SNR). In this report, the feasibility of combined lung MR angiography, perfusion, and ventilation imaging is demonstrated in a porcine model. Ultrafast gradient-echo sequences have been used for 3D perfusion and angiographic imaging, in conju...

  16. Assessment of the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level in patients with emphysema

    International Nuclear Information System (INIS)

    Purpose: To assess the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level using CT and MRI in patients with emphysema. Material and methods: Forty-five patients with severe emphysema (GOLD III and IV) underwent inspiratory 3D-HRCT and contrast-enhanced MR-perfusion (1.5T; 3.5 mm x 1.9 mm x 4 mm). 3D-HRCT data was analyzed using a software for detection and visualization of emphysema. Emphysema was categorized in four clusters with different volumes and presented as overlay on the CT. CT and lung perfusion were visually analyzed for three lobes on each side using a four-point-score to grade the abnormalities on CT (1: predominantly small emphysema-clusters to 4: >75% large emphysema-clusters) and MRI (1: normal perfusion to 4: no perfusion). Results: A total of 270 lobes were evaluated. At CT, the score was 1 for 9 lobes, 2 for 43, 3 for 77, and 4 for 141 lobes. At MRI, the score was 1 for 13 lobes, 2 for 45, 3 for 92, and 4 for 120 lobes. Matching of lung parenchymal destruction and reduced perfusion was found in 213 lobes (weighted kappa = 0.8). The score was higher on CT in 44, and higher on MRI in 13 lobes. Conclusion: 3D-HRCT and 3D MR-perfusion show a high lobar agreement between parenchymal destruction and reduction of perfusion in patients with severe emphysema

  17. Non-invasive perfusion imaging by modified STAR using asymmetric inversion slabs (ASTAR)

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Tokunori [Toshiba Nasu Works, Otawara, Tochigi (Japan)

    2000-12-01

    Arterial spin labeling (ASL) such as STAR, EPISTAR, and FAIR have been used as imaging techniques of tissue perfusion and blood vessels (in MRA). We have developed 'ASTAR', a modified version of STAR by using asymmetric inversion slabs. ASTAR solves the problems of suppression of venous inflow and subtraction error of stationary tissue signal caused by the imbalance of signal variations. The signal variations are dependent on MT effects. In order to avoid overlapping the control slab to the tissue (including large veins), the control and tag slabs are arranged asymmetrically to preserve the same offset of modulation frequency. We evaluated both the subtraction error caused by the MT effects, and the imperfection of an IR slab using a stationary phantom. We then measured the vessel signal on the brain of a volunteer, using the above methods. Two indexes were used for the evaluation: ASL signal to control signal ratio (ASLR [%]=100*deltaS/S{sub cont}) and ASL signal to noise ratio (ASLNR=delatS/Noise) where deltaS=|S{sub cont}-S{sub tag}|. Phantom study: each ASLR and ASLNR between ASTAR and EPISTAR was comparable and showed a decrease in noise signal level. This means that the ASL signal from the stationary tissue with an imbalance in MT effects and the imperfection in inversion slab profiles were cancelled out almost perfectly. When calculating CBF, ASLR for zero perfusion stationary tissue should be below 0.1%. We were able to satisfy this requirement in our ASTAR experiment. ASLR and ASLNR in FAIR were 40% larger than in EPISTAR and ASTAR. Volunteer brain study: compared with each ASL image, the MT effects were cancelled out in EPISTAR and ASTAR. Veins (sagittal sinus etc) disappeared in STAR and ASTAR, but were visible in EPISTAR and FAIR. Perfusion signals were similar in ASTAR and EPISTAR, indicating that both cancellation of MT effects and venous inflow from the opposite side of the tag were suppressed in ASTAR. In conclusion, ASTAR is a practical

  18. Human brain: reliability and reproducibility of pulsed arterial spin-labeling perfusion MR imaging.

    Science.gov (United States)

    Jahng, Geon-Ho; Song, Enmin; Zhu, Xiao-Ping; Matson, Gerald B; Weiner, Michael W; Schuff, Norbert

    2005-03-01

    The Committee of Human Research of the University of California San Francisco approved this study, and all volunteers provided written informed consent. The goal of this study was to prospectively determine the global and regional reliability and reproducibility of noninvasive brain perfusion measurements obtained with different pulsed arterial spin-labeling (ASL) magnetic resonance (MR) imaging methods and to determine the extent to which within-subject variability and random noise limit reliability and reproducibility. Thirteen healthy volunteers were examined twice within 2 hours. The pulsed ASL methods compared in this study differ mainly with regard to magnetization transfer and eddy current effects. There were two main results: (a) Pulsed ASL MR imaging consistently had high measurement reliability (intraclass correlation coefficients greater than 0.75) and reproducibility (coefficients of variation less than 8.5%), and (b) random noise rather than within-subject variability limited reliability and reproducibility. It was concluded that low signal-to-noise ratios substantially limit the reliability and reproducibility of perfusion measurements.

  19. Measuring blood delivery to solitary pulmonary nodules using perfusion magnetic resonance imaging

    Science.gov (United States)

    Zheng, Wei; Wang, Zhifeng; Shen, Li; Gao, Ling; Ford, James C.; Makedon, Fillia S.; Pearlman, Justin D.

    2006-03-01

    With perfusion magnetic resonance imaging (pMRI), perfusion describes the amount of blood passing through a block of tissue in a certain period of time. In pMRI, the tissue having more blood passing through will show higher intensity value as more contrast-labeled blood arrives. Perfusion reflects the delivery of essential nutrients to a block of tissue, and is an important parameter for the tissue status. Considering solitary pulmonary nodules (SPN), perfusion differences between malignant and benign nodules have been studied by different techniques. Much effort has been put into its characterization. In this paper, we proposed and implemented extraction of the SPN time intensity profile to measure blood delivery to solitary pulmonary nodules, describing their perfusion effects. In this method, a SPN time intensity profile is created based on intensity values of the solitary pulmonary nodule in lung pMRI images over time. This method has two steps: nodule tracking and profile clustering. Nodule tracking aligns the solitary pulmonary nodule in pMRI images taken at different time points, dealing with nodule movement resulted from breathing and body movement. Profile clustering implements segmentation of the nodule region and extraction of the time intensity profile of a solitary pulmonary nodule. SPN time intensity profiles reflect patterns of blood delivery to solitary pulmonary nodules, giving us a description of perfusion effect and indirect evidence of tumor angiogenesis. Analysis on SPN time intensity profiles will help the diagnosis of malignant nodules for early lung cancer detection.

  20. ASL Handshape Stories, Word Recognition and Signing Deaf Readers: An Exploratory Study

    Science.gov (United States)

    Gietz, Merrilee R.

    2013-01-01

    The effectiveness of using American Sign Language (ASL) handshape stories to teach word recognition in whole stories using a descriptive case study approach was explored. Four profoundly deaf children ages 7 to 8, enrolled in a self-contained deaf education classroom in a public school in the south participated in the story time five-week…

  1. Black Deaf Individuals' Reading Skills: Influence of ASL, Culture, Family Characteristics, Reading Experience, and Education

    Science.gov (United States)

    Myers, Candace; Clark, M. Diane; Musyoka, Millicent M.; Anderson, Melissa L.; Gilbert, Gizelle L.; Agyen, Selina; Hauser, Peter C.

    2010-01-01

    Previous research on the reading abilities of Deaf individuals from various cultural groups suggests that Black Deaf and Hispanic Deaf individuals lag behind their White Deaf peers. The present study compared the reading skills of Black Deaf and White Deaf individuals, investigating the influence of American Sign Language (ASL), culture, family…

  2. Mentorship: Mutual Benefits for ASL Students and Gifted Students (Part 1)

    Science.gov (United States)

    Buisson, Gerald J.; Salgo, Jennifer

    2012-01-01

    Postsecondary American Sign Language (ASL) students are capable of teaching short lessons related to sign language and Deaf culture to gifted students in elementary school. College students who work as "interest-area mentors" benefit gifted students while building their own academic discipline and professional skills. In Part 1 of a 2-part series…

  3. The Sign "Institute" and Its Derivatives: A Family of Culturally Important ASL Signs

    Science.gov (United States)

    Kowalsky, Jilly; Meier, Richard P.

    2013-01-01

    The sign "institute" is the source of a family of ASL signs that are used to refer to residential schools for deaf children and to other institutions. The members of the "institute" sign family--although initialized--are well-established within the Deaf community and, importantly, are used to refer to highly-valued aspects of Deaf culture. This is…

  4. 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.)

  5. 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.)

  6. MRI Scans

    Science.gov (United States)

    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from ...

  7. Academic Achievement of Deaf and Hard-of-Hearing Students in an ASL/English Bilingual Program.

    Science.gov (United States)

    Hrastinski, Iva; Wilbur, Ronnie B

    2016-04-01

    There has been a scarcity of studies exploring the influence of students' American Sign Language (ASL) proficiency on their academic achievement in ASL/English bilingual programs. The aim of this study was to determine the effects of ASL proficiency on reading comprehension skills and academic achievement of 85 deaf or hard-of-hearing signing students. Two subgroups, differing in ASL proficiency, were compared on the Northwest Evaluation Association Measures of Academic Progress and the reading comprehension subtest of the Stanford Achievement Test, 10th edition. Findings suggested that students highly proficient in ASL outperformed their less proficient peers in nationally standardized measures of reading comprehension, English language use, and mathematics. Moreover, a regression model consisting of 5 predictors including variables regarding education, hearing devices, and secondary disabilities as well as ASL proficiency and home language showed that ASL proficiency was the single variable significantly predicting results on all outcome measures. This study calls for a paradigm shift in thinking about deaf education by focusing on characteristics shared among successful deaf signing readers, specifically ASL fluency. PMID:26864688

  8. When Is a Pidgin Not a Pidgin? An Alternate Analysis of the ASL-English Contact Situation.

    Science.gov (United States)

    Cokely, Dennis

    1983-01-01

    Recent sociolinguistic research is used to show that the American Sign Language (ASL)-English contact situation does not result in the emergence of a pidgin as supposed. Variation along the ASL-English continuum can be accounted for by interplay of foreigner talk, judgments of proficiency, and learners' attempts to master the target language.…

  9. Bilingual Processing of ASL-English Code-Blends: The Consequences of Accessing Two Lexical Representations Simultaneously

    Science.gov (United States)

    Emmorey, Karen; Petrich, Jennifer A. F.; Gollan, Tamar H.

    2012-01-01

    Bilinguals who are fluent in American Sign Language (ASL) and English often produce "code-blends"--simultaneously articulating a sign and a word while conversing with other ASL-English bilinguals. To investigate the cognitive mechanisms underlying code-blend processing, we compared picture-naming times (Experiment 1) and semantic categorization…

  10. MRI of the pulmonary parenchyma

    International Nuclear Information System (INIS)

    Imaging of the pulmonary parenchyma represents a unique challenge for MRI. Limited signal is caused by low proton density, susceptibility artifacts, and physiological motion (cardiac pulsation, respiration). Recently, further improvements in MRI techniques have widened the potential for investigations of pulmonary parenchymal disease. These include very short echo times, ultrafast turbo-spin-echo acquisitions, projection reconstruction technique, breathhold imaging, ECG triggering, contrast agents (perfusion imaging, aerosols), sodium imaging, hyperpolarized noble gas imaging, and oxygen enhancement. By using widely available techniques, MRI is helpful in the assessment of (a) acute alveolitic processes in chronic infiltrative lung disease, (b) detection and characterization of pulmonary nodules, (c) detection, characterization, and follow-up of pneumonia, (d) differentiation of obstructive atelectasis from non-obstructive atelectasis and infarctions, and (e) measurements of lung water content. Chronic bronchitis, bronchiectasis, and emphysema are not readily assessable by routine MRI techniques. More sophisticated techniques are under investigation for MR imaging of pulmonary ventilation and perfusion. They represent the beginning of functional MR imaging of the lung which will be established in the future. (orig.)

  11. MRI of the pulmonary parenchyma

    Energy Technology Data Exchange (ETDEWEB)

    Kauczor, H.U.; Kreitner, K.F. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie

    1999-07-01

    Imaging of the pulmonary parenchyma represents a unique challenge for MRI. Limited signal is caused by low proton density, susceptibility artifacts, and physiological motion (cardiac pulsation, respiration). Recently, further improvements in MRI techniques have widened the potential for investigations of pulmonary parenchymal disease. These include very short echo times, ultrafast turbo-spin-echo acquisitions, projection reconstruction technique, breathhold imaging, ECG triggering, contrast agents (perfusion imaging, aerosols), sodium imaging, hyperpolarized noble gas imaging, and oxygen enhancement. By using widely available techniques, MRI is helpful in the assessment of (a) acute alveolitic processes in chronic infiltrative lung disease, (b) detection and characterization of pulmonary nodules, (c) detection, characterization, and follow-up of pneumonia, (d) differentiation of obstructive atelectasis from non-obstructive atelectasis and infarctions, and (e) measurements of lung water content. Chronic bronchitis, bronchiectasis, and emphysema are not readily assessable by routine MRI techniques. More sophisticated techniques are under investigation for MR imaging of pulmonary ventilation and perfusion. They represent the beginning of functional MR imaging of the lung which will be established in the future. (orig.)

  12. 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.

  13. Myocardial perfusion imaging with dual energy CT.

    Science.gov (United States)

    Jin, Kwang Nam; De Cecco, Carlo N; Caruso, Damiano; Tesche, Christian; Spandorfer, Adam; Varga-Szemes, Akos; Schoepf, U Joseph

    2016-10-01

    Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  14. Isolated lung perfusion.

    Science.gov (United States)

    Cypel, Marcelo; Keshavjee, Shaf

    2012-01-01

    Isolated lung perfusion (ILP) has been historically used as a method to study basic lung physiologic concepts using animal models. More recently, ILP has been applied in lung transplantation and thoracic oncology. In lung transplantation, ILP has been used to assess physiological integrity of donor lungs after the organ is removed from the donor. This procedure is called Ex vivo Lung Perfusion (EVLP), and it has also been proposed as a method for active treatment and repair of injured unsuitable donor organs ex vivo. In oncology, ILP is an attractive method to deliver high dose chemotherapy to treat pulmonary metastatic disease. Since the lung vasculature is isolated in vivo, this technique is called in vivo lung perfusion (IVLP). This review will focus on the rationale, technical aspects, experimental and clinical experience of EVLP and IVLP. A perspective on the future use of these techniques is described. PMID:22202033

  15. Ex vivo lung perfusion.

    Science.gov (United States)

    Reeb, Jeremie; Cypel, Marcelo

    2016-03-01

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

  16. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

  17. Perfusion deficits and functional connectivity alterations in patients with post-traumatic stress disorder

    Science.gov (United States)

    Liu, Yang; Li, Baojuan; Zhang, Xi; Zhang, Linchuan; Li, Liang; Lu, Hongbing

    2016-03-01

    To explore the alteration in cerebral blood flow (CBF) and functional connectivity between survivors with recent onset post-traumatic stress disorder (PTSD) and without PTSD, survived from the same coal mine flood disaster. In this study, a processing pipeline using arterial spin labeling (ASL) sequence was proposed. Considering low spatial resolution of ASL sequence, a linear regression method was firstly used to correct the partial volume (PV) effect for better CBF estimation. Then the alterations of CBF between two groups were analyzed using both uncorrected and PV-corrected CBF maps. Based on altered CBF regions detected from the CBF analysis as seed regions, the functional connectivity abnormities in PTSD patients was investigated. The CBF analysis using PV-corrected maps indicates CBF deficits in the bilateral frontal lobe, right superior frontal gyrus and right corpus callosum of PTSD patients, while only right corpus callosum was identified in uncorrected CBF analysis. Furthermore, the regional CBF of the right superior frontal gyrus exhibits significantly negative correlation with the symptom severity in PTSD patients. The resting-state functional connectivity indicates increased connectivity between left frontal lobe and right parietal lobe. These results indicate that PV-corrected CBF exhibits more subtle perfusion changes and may benefit further perfusion and connectivity analysis. The symptom-specific perfusion deficits and aberrant connectivity in above memory-related regions may be putative biomarkers for recent onset PTSD induced by a single prolonged trauma exposure and help predict the severity of PTSD.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-01

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

  19. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable ext

  20. Black deaf individuals' reading skills: influence of ASL, culture, family characteristics, reading experience, and education.

    Science.gov (United States)

    Myers, Candace; Clark, M Diane; Musyoka, Millicent M; Anderson, Melissa L; Gilbert, Gizelle L; Agyen, Selina; Hauser, Peter C

    2010-01-01

    Previous research on the reading abilities of Deaf individuals from various cultural groups suggests that Black Deaf and Hispanic Deaf individuals lag behind their White Deaf peers. The present study compared the reading skills of Black Deaf and White Deaf individuals, investigating the influence of American Sign Language (ASL), culture, family characteristics, reading experience, and education. (The descriptor Black is used throughout the present article, as Black Deaf individuals prefer this term to African American. For purposes of parallel construction, the term White is used instead of European American.) It was found that Black Deaf study participants scored lower on measures of both reading and ASL. These findings provide implications for possible interventions at the primary, secondary, and college levels of education. PMID:21305979

  1. Codeswitching techniques: evidence-based instructional practices for the ASL/English bilingual classroom.

    Science.gov (United States)

    Andrews, Jean F; Rusher, Melissa

    2010-01-01

    The authors present a perspective on emerging bilingual deaf students who are exposed to, learning, and developing two languages--American Sign Language (ASL) and English (spoken English, manually coded English, and English reading and writing). The authors suggest that though deaf children may lack proficiency or fluency in either language during early language-learning development, they still engage in codeswitching activities, in which they go back and forth between signing and English to communicate. The authors then provide a second meaning of codeswitching--as a purpose-driven instructional technique in which the teacher strategically changes from ASL to English print for purposes of vocabulary and reading comprehension. The results of four studies are examined that suggest that certain codeswitching strategies support English vocabulary learning and reading comprehension. These instructional strategies are couched in a five-pronged approach to furthering the development of bilingual education for deaf students.

  2. Toward an example-based machine translation from written text to ASL using virtual agent animation

    CERN Document Server

    Boulares, Mehrez

    2012-01-01

    Modern computational linguistic software cannot produce important aspects of sign language translation. Using some researches we deduce that the majority of automatic sign language translation systems ignore many aspects when they generate animation; therefore the interpretation lost the truth information meaning. Our goals are: to translate written text from any language to ASL animation; to model maximum raw information using machine learning and computational techniques; and to produce a more adapted and expressive form to natural looking and understandable ASL animations. Our methods include linguistic annotation of initial text and semantic orientation to generate the facial expression. We use the genetic algorithms coupled to learning/recognized systems to produce the most natural form. To detect emotion we are based on fuzzy logic to produce the degree of interpolation between facial expressions. Roughly, we present a new expressive language Text Adapted Sign Modeling Language TASML that describes all ...

  3. The Analysis of Correlation between DCE-MRI Perfusion Index and MR DWI ADC in Prostate Cancer Patients%DCE-MRI灌注指标与 MR DWI ADC 值在前列腺癌患者中的关系分析

    Institute of Scientific and Technical Information of China (English)

    崔凌; 庄伟雄; 文海忠

    2014-01-01

    Objective To explore the correlation between dynamic contrast-enhanced MRI ( DCE-MRI) and MR DWI ADC of prostate cancer .Methods 53 prostate cancer patients confirmed with pathology underwent DCE-MRI using 3.0 T MR liver acquisition with volume acceleration ( LAVA) and DWI.Signal intensity-time( SI-T) of cancerous and non-cancerous regions in peripheral prostate zone were acquired ,and the time to minimum(Tmax),the whole enhancement degree (Simax) and the max-imum slope(Rmax) were calculated.ADC in DWI was assessed,and the correlation with perfusion indexes in DCE-MRI was ana-lyzed statistically .Results The value of Tmax ,Simax and Rmax in cancerous and non-cancerous regions were statistical signifi-cantly (P<0.05).The ADC value in cancerous and non-cancerous regions were (1.59 ±0.11) ×10 -3 mm2/s and (0.88 ± 0.16) ×10 -3mm2/s,it was statistical significantly (P<0.05).There was positive correlation between Tmax and ADC ,and nega-tive correlation between Rmax and Simax in cancerous regions of prostate cancer .Conclusion Perfusion indexes of DCE-MRI are correlated with ADC in prostate cancer .DCE-MRI combined with DWI might improve the accuracy of detection ,localization and staging of prostate cancer .%目的:探讨DCE-MRI灌注指标与MR DWI ADC值在前列腺癌患者中的相关性。方法选取前列腺癌患者53例,且均经病理组织切片活检确诊,进行DWI检查以及肝脏快速容积采集序列( LAVA)动态增强扫描,从而得到前列腺两侧外周带非癌区和癌区信号强度-时间( SI-T)曲线,并计算得到最快强化率( Rmax )、达峰时间( Tmax )和最大强化程度(SImax)。最终分析得到DCE-MRI灌注指标与MRD WI ADC值之间的相关性。结果在DCE-MRI中,癌灶在早期即有快速和明显的强化,在Tmax、SImax和Rmax等指标上同非癌区相比,差异显著,具有统计学意义(P<0.05)。前列腺非癌区和癌区ADC值分别为(1.59±0.11)×10

  4. Liver perfusion in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI): comparison of enhancement in Gd-BT-DO3A and Gd-EOB-DTPA in normal liver parenchyma

    Energy Technology Data Exchange (ETDEWEB)

    Schalkx, Hanke J.; Bosch, Maurice A.A.J. van den; Veldhuis, Wouter B.; Leeuwen, Maarten S. van [University Medical Center Utrecht, Department of Radiology, PO Box 58800, Utrecht (Netherlands); Stralen, Marijn van; Pluim, Josien P.W. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Coenegrachts, Kenneth [Department of Radiology, Bruges (Belgium); Kessel, Charlotte S. van; Hillegersberg, Richard van [University Medical Center Utrecht, Department of Surgery, Utrecht (Netherlands); Erpecum, Karel J. van [University Medical Center Utrecht, Department of Gastroenterology, Utrecht (Netherlands); Verkooijen, Helena M. [University Medical Center Utrecht, Clinical epidemiologist, Department of Radiology, Utrecht (Netherlands)

    2014-09-15

    Within-patient comparison of the enhancement patterns of normal liver parenchyma after gadobutrol and gadoxetate disodium, with emphasis on the start of hepatocytic uptake of gadoxetate disodium. Twenty-one patients (12 female, 9 male) without chronic liver disease underwent 1.5-T contrast-enhanced MRI twice, once with an extracellular contrast agent (gadobutrol) and once with a hepatospecific agent (gadoxetate disodium), using a T1-weighted keyhole sequence. Fifteen whole-liver datasets were acquired up to 5 min for both contrast agents and two additional datasets, up to 20 min, for gadoxetate. Signal intensities (SI) of the parenchyma, aorta and portal vein were measured and analysed relative to pre-contrast parenchymal SI. After gadoxetate, in 29 % of the patients the parenchymal SI decreased by ≥5 % after the initial vascular-phase-induced peak, while in the other 71 % the parenchymal SI remained stable or gradually increased until up to 20 min after the initial peak. The hepatocytic gadoxetate uptake started at a mean of 37.8 s (SD 14.7 s) and not later than 76 s after left ventricle enhancement. Parenchymal enhancement due to hepatocytic uptake of gadoxetate can start as early as in the late arterial phase. This may confound the assessment of lesion appearance as compared to extracellular contrast such as gadobutrol. (orig.)

  5. A brief report on MRI investigation of experimental traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    Timothy Q.Duong; Lora T.Watts

    2016-01-01

    Traumatic brain injury is a major cause of death and disability. This is a brief report based on a symposium presentation to the2014 Chinese Neurotrauma Association Meeting in San Francisco, USA. It covers the work from our laboratory in applying multimodal MRI to study experimental traumatic brain injury in rats with comparisons made to behavioral tests and histology. MRI protocols include structural, perfusion, manganese-enhanced, diffusion-tensor MRI, and MRI of blood-brain barrier integrity and cerebrovascular reactivity.

  6. 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

  7. Reproducibility of magnetic resonance perfusion imaging.

    Directory of Open Access Journals (Sweden)

    Xiaomeng Zhang

    Full Text Available Dynamic MR biomarkers (T2*-weighted or susceptibility-based and T1-weighted or relaxivity-enhanced have been applied to assess tumor perfusion and its response to therapies. A significant challenge in the development of reliable biomarkers is a rigorous assessment and optimization of reproducibility. The purpose of this study was to determine the measurement reproducibility of T1-weighted dynamic contrast-enhanced (DCE-MRI and T2*-weighted dynamic susceptibility contrast (DSC-MRI with two contrast agents (CA of different molecular weight (MW: gadopentetate (Gd-DTPA, 0.5 kDa and Gadomelitol (P792, 6.5 kDa. Each contrast agent was tested with eight mice that had subcutaneous MDA-MB-231 breast xenograft tumors. Each mouse was imaged with a combined DSC-DCE protocol three times within one week to achieve measures of reproducibility. DSC-MRI results were evaluated with a contrast to noise ratio (CNR efficiency threshold. There was a clear signal drop (>95% probability threshold in the DSC of normal tissue, while signal changes were minimal or non-existent (<95% probability threshold in tumors. Mean within-subject coefficient of variation (wCV of relative blood volume (rBV in normal tissue was 11.78% for Gd-DTPA and 6.64% for P792. The intra-class correlation coefficient (ICC of rBV in normal tissue was 0.940 for Gd-DTPA and 0.978 for P792. The inter-subject correlation coefficient was 0.092. Calculated K(trans from DCE-MRI showed comparable reproducibility (mean wCV, 5.13% for Gd-DTPA, 8.06% for P792. ICC of K(trans showed high intra-subject reproducibility (ICC = 0.999/0.995 and inter-subject heterogeneity (ICC = 0.774. Histograms of K(trans distributions for three measurements had high degrees of overlap (sum of difference of the normalized histograms <0.01. These results represent homogeneous intra-subject measurement and heterogeneous inter-subject character of biological population, suggesting that perfusion MRI could be an imaging biomarker to

  8. Aslı Erdoğan'ın Anlatılarında Ontolojik Sorunlar Ontological Problems in Aslı Erdoğan's Narratives

    Directory of Open Access Journals (Sweden)

    Mehmet ÖZGER

    2012-12-01

    Full Text Available The issue of existence in Aslı Erdoğan's narratives will be examined in this article. Aslı Erdoğan is one of the leading female autor in the last term Turkish Literature. Having written sort stories, novelsand essays the autor became famous with her artistic creativity. It canbe talked about two interwoven adventures in Aslı Erdoğan’s Works.The adventures in the outside world are accompanied by the heroes’adventures of an inner worlds. Heroes appear to be almost all alone, nothold, competing with backgrounds and themselves, living in a constantfeeling of emptiness and nothingness, who are looking to a meaningtoward lack and devastation in their lives. In this context, it seems thatexistential concepts and trajectory are in the forefront rather than plotin which speeches and interviews gained density. The circumstancesand details which shape human existence and attitude toward life areemphasized. The main problem of the narrative heroes is the alienationand the other existential problems that we see in narrative areconditions that become visible with other existential alienationproblems. It is seen that heroes are alienated particularly againstthemselves, environment and society. In this respect in the alienation ofnarrative, as a type of alienation themes like individual anomie andaccordingly, solitude, nothingness / space, escape / exile, death andsuicide and so on stand out. This narrative themes are important inrevealing the psychological world of the heroes as well as to reveal thepsychology of the author. Bu yazıda Aslı Erdoğan’ın anlatılarında varoluş sorunsalı incelenecektir. Aslı Erdoğan son dönem Türk edebiyatının önemli kadın yazarlarından biridir. Öykü, roman, deneme türlerinde eserler kaleme alan sanatçı, sanatsal yaratıcılık yeteneğiyle adından söz ettirmeyi başarmıştır. Aslı Erdoğan’ın eserlerinde iç içe geçmiş iki serüvenden bahsedilebilir. Kahramanların dış dünyadaki ser

  9. Advances of blood oxygen-level dependent MRI in muscular system

    International Nuclear Information System (INIS)

    BOLD-fMRI has been applied to muscular system to observe muscular pathophysiological change after performing a task and show the characteristics of muscle perfusion. This paper mainly introduces the scanning sequence, common tasking methods, such as cuff compression, excise, oxygen and drug, etc. It also introduces clinical study of perfusion reserve of muscular tissue with abnormal blood vessels. (authors)

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  11. Ex vivo lung perfusion

    OpenAIRE

    Machuca, Tiago N; Cypel, Marcelo

    2014-01-01

    Lung transplantation (LTx) is an established treatment option for eligible patients with end-stage lung disease. Nevertheless, the imbalance between suitable donor lungs available and the increasing number of patients considered for LTx reflects in considerable waitlist mortality. Among potential alternatives to address this issue, ex vivo lung perfusion (EVLP) has emerged as a modern preservation technique that allows for more accurate lung assessment and also improvement of lung function. I...

  12. Voxel-based analysis of cerebral perfusion changes in Alzheimer's disease using a novel 3D arterial spin-labeling technique%基于体素分析的三维动脉自旋标记成像在阿尔茨海默病脑血流灌注中的应用研究

    Institute of Scientific and Technical Information of China (English)

    凌华威; 张泳; 丁蓓; 黄娟; 张欢; 王涛; 柴维敏; 陈克敏

    2012-01-01

    Objective 3D pulsed continuous arterial spin labeling (ASL) technique was used to study cerebral blood flow (CBF) changes in patients with Alzheimer's disease (AD) in comparison with age- and gender-matched healthy controls. Methods 3D ASL scans was performed in 45 participants (24 AD patients and 21 age- and gender-matched control subjects) covering the entire brain with a 3.0-T MR system. Voxel based analysis was performed using SPM8. Two sample t test (threshold at P<0.05 ) was performed. Results Significant decrease of CBF was observed in bilateral temporal-parietal-occipital cortex and left limbic lobe in AD patients when compared with control group. Interestingly, increased CBF was observed in bilateral thalamus, right caudate nucleus and putamen, paracentral lobule as well as white matter of right temporal lobe. Conclusions Our voxel-based results indicates that ASL-MRI could provide useful perfusion information in AD patients. Because of its easy acquisition and noninvasiveness, ASL-MRI may be an appealing alternative approach for further pathologic and neuropsychological studies of AD.%目的:利用三维(3D)动脉自旋标记(arterial spin labeling,ASL)成像技术探讨阿尔茨海默病(Alzheimer's disease,AD)患者的脑血流灌注特征.方法:选择24例AD患者和21名年龄、性别匹配的健康老年人,采用ASL序列进行灌注成像.将获取的脑血流图像(cerebral blood flow,CBF)采用基于体素分析方法经后处理配准进行全脑分析,比较2组的脑血流灌注情况,并探讨AD患者的脑血流灌注特征.结果:与正常老年人相比,AD患者的双侧颞枕顶叶皮层、左侧边缘叶及左侧胼胝体压部的脑血流量CBF明显降低,同时双侧丘脑、右侧壳核、右尾状核头部及右侧颞叶白质区的CBF明显增高.结论:基于体素的ASL全脑分析揭示了AD认知损害过程中相关脑区的血流灌注异常,作为一种无创的血流动力学检查新技术,ASL可能对进一步研究AD

  13. Perfusion based cell culture chips

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

    2010-01-01

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures...... and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers....

  14. Reverse ventilation--perfusion mismatch

    Energy Technology Data Exchange (ETDEWEB)

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients.

  15. Establishment of a Swine Model for Validation of Perfusion Measurement by Dynamic Contrast-Enhanced Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Anika Sauerbrey

    2014-01-01

    Full Text Available The aim of the study was to develop a suitable animal model for validating dynamic contrast-enhanced magnetic resonance imaging perfusion measurements. A total of 8 pigs were investigated by DCE-MRI. Perfusion was determined on the hind leg musculature. An ultrasound flow probe placed around the femoral artery provided flow measurements independent of MRI and served as the standard of reference. Images were acquired on a 1.5 T MRI scanner using a 3D T1-weighted gradient-echo sequence. An arterial catheter for local injection was implanted in the femoral artery. Continuous injection of adenosine for vasodilation resulted in steady blood flow levels up to four times the baseline level. In this way, three different stable perfusion levels were induced and measured. A central venous catheter was used for injection of two different types of contrast media. A low-molecular weight contrast medium and a blood pool contrast medium were used. A total of 6 perfusion measurements were performed with a time interval of about 20–25 min without significant differences in the arterial input functions. In conclusion the accuracy of DCE-MRI-based perfusion measurement can be validated by comparison of the integrated perfusion signal of the hind leg musculature with the blood flow values measured with the ultrasound flow probe around the femoral artery.

  16. Toward an example-based machine translation from written text to ASL using virtual agent animation

    Directory of Open Access Journals (Sweden)

    Mehrez Boulares

    2012-01-01

    Full Text Available Modern computational linguistic software cannot produce important aspects of sign language translation. Using some researches we deduce that the majority of automatic sign language translation systems ignore many aspects when they generate animation; therefore the interpretation lost the truth information meaning. This problem is due to sign language consideration as a derivative language, but it is a complete language with its own unique grammar. This grammar is related to semantic-cognitive models of spatially, time, action and facial expression to represent complex information to make sign interpretation more efficiently, smooth, expressive and natural-looking human gestures. All this aspects give us useful insights into the design principles that have evolved in natural communication between people. In this work we are interested in American Sign Language, because it is the simplest and most standardized sign language. Our goals are: to translate written text from any language to ASL animation; to model maximum raw information using machine learning and computational techniques; and to produce a more adapted and expressive form to natural looking and understandable ASL animations. Our methods include linguistic annotation of initial text and semantic orientation to generate the facial expression. We use genetic algorithms coupled to learning/recognized systems to produce the most natural form. To detect emotion we based on fuzzy logic to produce the degree of interpolation between facial expressions. Roughly, we present a new expressive language Text Adapted Sign Modeling Language TASML that describes all maximum aspects related to a good sign language interpretation. This paper is organized as follow: the next section is devoted to present the comprehension effect of using Space/Time/SVO form in ASL animation based on experimentation. In section 3, we describe our technical considerations. We present the general approach we adopted to

  17. Ventilation-perfusion emission tomography

    International Nuclear Information System (INIS)

    The ventilation-perfusion research with SPECT is discussed. With SPECT three dimensional activity distribution can be made. Perfusion scintigraphy can be done with 99m-Tc labeled particles, ventilation scintigraphy can only be done with 81m-Kr or labeled aerosols. A disadvantage in using 99m-Tc is interference with labeled perfusion tracers. For a reliable quantification the ventilation and perfusion pictures should be registered at the same time, the energies of both tracers must lay far apart and in quantification of regional ventilation from 81m-Kr activity distribution correction must be made for differences in regional specific ventilation. 4 refs.; 3 figs

  18. Diode pumping of Nd:ASL and its frequency doubling for blue emission around 450 nm

    OpenAIRE

    Pabœuf, David; Lucas-Leclin, Gaëlle; Georges, Patrick; Sumpf, Bernd; Erbert, Götz; Varona, Cyrille; Loiseau, Pascal; Aka, Gérard; Ferrand, Bernard

    2008-01-01

    International audience We present the diode pumping of a Nd-doped strontium and lanthanum (Nd:ASL) crystal Sr1-xLax-yNdyMgxAl12-xO19 (0.05 ≤ x ≤ 0.5; y = 0.05) for second harmonic generation around 450 nm. In order to fulfill the pumping requirements of this crystal, we have developed a high-brightness pump source based on a tapered amplifier in an extended cavity with a volume Bragg grating for wavelength stabilization. A pump brightness of 110 MW.cm-2sr-1 has been obtained with a linewid...

  19. Pediatric MRI

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Study of Normal Brain Development is a longitudinal study using anatomical MRI, diffusion tensor imaging (DTI), and MR spectroscopy (MRS) to map pediatric...

  20. Recognition of American Sign Language (ASL) Classifiers in a Planetarium Using a Head-Mounted Display

    Science.gov (United States)

    Hintz, Eric G.; Jones, Michael; Lawler, Jeannette; Bench, Nathan

    2015-01-01

    A traditional accommodation for the deaf or hard-of-hearing in a planetarium show is some type of captioning system or a signer on the floor. Both of these have significant drawbacks given the nature of a planetarium show. Young audience members who are deaf likely don't have the reading skills needed to make a captioning system effective. A signer on the floor requires light which can then splash onto the dome. We have examined the potential of using a Head-Mounted Display (HMD) to provide an American Sign Language (ASL) translation. Our preliminary test used a canned planetarium show with a pre-recorded sound track. Since many astronomical objects don't have official ASL signs, the signer had to use classifiers to describe the different objects. Since these are not official signs, these classifiers provided a way to test to see if students were picking up the information using the HMD.We will present results that demonstrate that the use of HMDs is at least as effective as projecting a signer on the dome. This also showed that the HMD could provide the necessary accommodation for students for whom captioning was ineffective. We will also discuss the current effort to provide a live signer without the light splash effect and our early results on teaching effectiveness with HMDs.This work is partially supported by funding from the National Science Foundation grant IIS-1124548 and the Sorenson Foundation.

  1. Sola ASL in Spectralite strikes the perfect balance between cosmetics and optics

    Science.gov (United States)

    Machol, Steven; Modglin, Luan

    1991-12-01

    The most rapidly growing segment of the ophthalmic lens market is the 'thin and light' segment. A major force for this growth has been the consumer, who wants thinner, lighter and better looking eyewear. In fact, the consumer demand for thin and light lenses increased by over 44% last year. There are essentially three options that allow thinner, lighter and flatter (more cosmetically appealing) lenses. These include: (1) a higher index material (higher than standard CR-39 registered or glass), (2) an aspheric design, or (3) a combination of both. However, current high index materials have certain properties that can affect the optical performance and ease of processing of spectacle lenses. Also, most current aspheric designs benefit only hyperopes, which represent about 30% of the spectacle lens wearers. Sola's ASL aspheric single vision lens in Spectralite combines a patented new high-index material with a specially flattened and aspheric design. This unique combination optimizes the traditional thin, light, and cosmetic benefits of high index while achieving optical performance comparable to CR-39. And, unlike other aspheric lenses, ASL in Spectralite is available in both plus and minus prescriptions, allowing you to meet the needs of more patients than ever before.

  2. Lung Ventilation/Perfusion Scan

    Science.gov (United States)

    ... two types of scans: ventilation and perfusion. The ventilation scan shows where air flows in your lungs. The perfusion scan shows where blood flows in your lungs. Both scans use radioisotopes (a low-risk radioactive substance). For the ventilation scan, you ...

  3. Validation of CT brain perfusion methods using a realistic dynamic head phantom

    NARCIS (Netherlands)

    Riordan, A.J.; Prokop, M.; Viergever, M.A.; Dankbaar, J.W.; Smit, E.J.; Jong, H.W. de

    2011-01-01

    PURPOSE: Development and evaluation of a realistic hybrid head phantom for the validation of quantitative CT brain perfusion methods. METHODS: A combination, or hybrid, of CT images of an anthropomorphic head phantom together with clinically acquired MRI brain images was used to construct a dynamic

  4. The search for neuroimaging biomarkers of Alzheimer's disease with advanced MRI techniques

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tie-Qiang (Karolinska Huddinge - Medical Physics, Stockholm (Sweden)), email: tieqiang.li@karolinska.se; Wahlund, Lars-Olof (Dept. of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm (Sweden))

    2011-02-15

    The aim of this review is to examine the recent literature on using advanced magnetic resonance imaging (MRI) techniques for finding neuroimaging biomarkers that are sensitive to the detection of risks for Alzheimer's disease (AD). Since structural MRI techniques, such as brain structural volumetry and voxel based morphometry (VBM), have been widely used for AD studies and extensively reviewed, we will only briefly touch on the topics of volumetry and morphometry. The focus of the current review is about the more recent developments in the search for AD neuroimaging biomarkers with functional MRI (fMRI), resting-state functional connectivity MRI (fcMRI), diffusion tensor imaging (DTI), arterial spin-labeling (ASL), and magnetic resonance spectroscopy (MRS)

  5. MRI and MSCT for the Assessment of Myocardial Function and Viability

    NARCIS (Netherlands)

    T. Baks (Timo)

    2006-01-01

    textabstractMRI is a versatile non-invasive imaging modality that can be applied in patients and in experimental models of ischemic heart disease. MRI allows refined assessment of regional and global left ventricular function and volumes, offers detailed information on myocardial perfusion and pe

  6. 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

  7. 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

  8. 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.

  9. Magnetic resonance imaging of pulmonary perfusion. Technical requirements and diagnostic impact; MRT der Lungenperfusion. Technische Voraussetzungen und diagnostischer Stellenwert

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, U.I.; Buesing, K.; Schoenberg, S.O.; Fink, C. [Klinikum Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Mannheim (Germany); Ingrisch, M.; Reiser, M. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Campus Grosshadern, Muenchen (Germany)

    2009-08-15

    With technical improvements in gradient hardware and the implementation of innovative k-space sampling techniques, such as parallel imaging, the feasibility of pulmonary perfusion MRI could be demonstrated in several studies. Dynamic contrast-enhanced 3D gradient echo sequences as used for time-resolved MR angiography have been established as the preferred pulse sequences for lung perfusion MRI. With these techniques perfusion of the entire lung can be visualized with a sufficiently high temporal and spatial resolution. In several trials in patients with acute pulmonary embolism, pulmonary hypertension and airway diseases, the clinical benefit and good correlation with perfusion scintigraphy have been demonstrated. The following review article describes the technical prerequisites, current post-processing techniques and the clinical indications for MR pulmonary perfusion imaging using MRI. (orig.) [German] Mit der Verfuegbarkeit leistungsfaehiger Gradientensysteme und schneller k-Raum-Akquisitionstechniken wie der parallelen Bildgebung konnten verschiedene Studien die Machbarkeit der Lungenperfusionsbildgebung in der MRT zeigen. In der Praxis haben sich dynamische kontrastverstaerkte 3D-Gradientenechosequenzen, wie sie fuer zeitaufgeloeste MR-Angiographien verwendet werden, fuer die Bildgebung der Lungenperfusion etabliert. Hiermit ist es moeglich, die Perfusion der gesamten Lunge mit ausreichend hoher zeitlicher und raeumlicher Aufloesung zu visualisieren. In mehren klinischen Studien konnte bei Patienten mit Lungenembolie, pulmonaler Hypertonie sowie Erkrankungen der Atemwege und des Lungenparenchyms der klinische Nutzen der Lungenperfusions-MRT und die gute Uebereinstimmung mit der Lungenperfusionsszintigraphie nachgewiesen werden. Der folgende Uebersichtsartikel beschreibt die technische Durchfuehrung, Bildnachverarbeitung und die klinischen Anwendungsgebiete der MRT zur Untersuchung der Lungenperfusion. (orig.)

  10. Quantitative myocardial perfusion in mice based on the signal intensity of flow sensitized CMR

    Directory of Open Access Journals (Sweden)

    Abeykoon Sumeda

    2012-10-01

    Full Text Available Abstract Background In the conventional approach to arterial spin labeling in the rodent heart, the relative difference in the apparent T1 relaxation times corresponding to selective and non-selective inversion is related to perfusion via a two compartment model of tissue. But accurate determination of T1 in small animal hearts is difficult and prone to errors due to long scan times and high heart rates. In this study we introduce the theoretical frame work for an alternative method (SI-method based purely on the signal intensity of slice-select and non-select inversion recovery images at a single inversion time at short repetition time. Methods A modified Bloch equation was solved to derive perfusion as a function of signal intensity of flow sensitized segmented gradient echo acquisitions. A two compartment fast exchanging model of tissue was assumed. To test the new technique first it was implemented on a flow phantom and then it was compared with the conventional T1 method in an in vivo study of healthy C57BL/6 mice (n=12. Finally the SI-method was used in comparison to a Late Gadolinium Enhanced (LGE method to qualitatively and quantitatively assess perfusion deficits in an ischemia-reperfusion mouse model (n=4. Results The myocardial perfusion of healthy mice obtained by the SI-method, 5.6 ± 0.5 ml/g/min, (mean ± standard deviation was similar (p=0.38 to that obtained by the conventional method, 5.6 ± 0.3 ml/g/min. The variance in perfusion within the left ventricle was less for the SI-method than that for the conventional method (p Conclusions The proposed signal intensity based ASL method with a segmented acquisition scheme allows accurate high resolution perfusion mapping in small animals. It’s short scan time, high reproducibility and ease of post process makes it a robust alternative to the conventional ASL technique that relies on T1 measurements.

  11. Portable MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  12. MRI Artifacts

    Directory of Open Access Journals (Sweden)

    Abed Al Nasser Assi

    2009-12-01

    Full Text Available   "nMagnetic resonance imaging (MRI has become more and more frequently used in medical imaging diagnostic in recent years. Radiologists and technicians working at these systems are relatively often confronted with image artifacts related to the radiowave with strong magnetic in the scanner. Many artifacts may be corrected or modulated through an understanding of their cause. This requires familiarity with scanner design; theory of operation; and image acquisition. The purpose of this review article is to present the most relevant artifacts that arise in MRI scanner, to provide some physical background on the formation of artifacts, and to suggest strategies to reduce or avoid these artifacts. The most frequent artifacts that can occur during MRI scanning are Motion related artifacts; Para-magnetic artifacts; Phase Wrap artifacts; Frequency artifacts; Susceptibility artifacts; Clipping artefact; Chemical Shift artifact and "Zebra" artefact .    "n  

  13. Development of MRI techniques for the assessment of chronic kidney disease

    OpenAIRE

    Buchanan, Charlotte E.

    2016-01-01

    It is well established that patients with Chronic Kidney Disease (CKD) are more susceptible to develop cardiovascular disease in comparison to the healthy population. This thesis aims to develop and apply MRI techniques to assess the human heart and kidney in patients with chronic kidney disease (CKD). Magnetic resonance imaging (MRI) can be used to inform on structure, function, perfusion and blood flow, without the need for ionizing radiation. In order to assess blood flow using MRI, ga...

  14. MRI Safety during Pregnancy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z MRI Safety During Pregnancy Magnetic resonance imaging (MRI) Illness ... during the exam? Contrast material MRI during pregnancy Magnetic resonance imaging (MRI) If you are pregnant and your doctor ...

  15. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

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

    1994-01-01

    The sensitivity of MR gradient echo imaging towards CO2 induced changes in cerebral blood flow was investigated in 10 normal subjects. The subjects were inhaling 5% and 7% CO2 and the experiments were carried out at 1.5 T (n = 6) and 2.0 T (n = 5), allowing a comparison of field strengths. Additi...

  16. Functional MRI of CO2 induced increase in cerebral perfusion

    DEFF Research Database (Denmark)

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

    1994-01-01

    The sensitivity of MR gradient echo imaging towards CO2 induced changes in cerebral blood flow was investigated in 10 normal subjects. The subjects were inhaling 5% and 7% CO2 and the experiments were carried out at 1.5 T (n = 6) and 2.0 T (n = 5), allowing a comparison of field strengths...

  17. Fetal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, D.; Brugger, P.C. [University Hospital of Vienna (Austria). Division of Neuroradiology

    2004-07-01

    New, ultrafast sequences have made it possible to obtain MR images of the fetus without maternal sedation or immobilization of the fetus itself. While fetal MRI began as an adjunct to ultrasound, it has now been shown that MRI can provide additional information that may change prognosis, the management of pregnancy, or the treatment of the newborn child. It is of particular value in the assessment of malformations of the central nervous system. The steady development and adaptation of MR-sequences to the needs of fetal imaging has led to new indications that can support prognostic and therapeutic decisions. (orig.)

  18. 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.)

  19. Multi-detector CT perfusion

    Directory of Open Access Journals (Sweden)

    Ashraf M. Enite

    2016-09-01

    Conclusion: CTP is a promising non-invasive technique assessing the efficacy, predicting early response to local treatment therapies and monitoring tumor recurrence. It assesses the degree of post therapy tumor perfusion especially the degree of arterialization.

  20. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard proced...

  1. Fetal MRI

    International Nuclear Information System (INIS)

    Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

  2. Ex-vivo lung perfusion.

    Science.gov (United States)

    Van Raemdonck, Dirk; Neyrinck, Arne; Cypel, Marcelo; Keshavjee, Shaf

    2015-06-01

    This review outlines the new and promising technique of ex vivo lung perfusion and its clinical potential to increase the number of transplantable lungs and to improve the early and late outcome after transplantation. The rationale, the experimental background, the technique and protocols, and available devices for ex vivo lung perfusion are discussed. The current clinical experience worldwide and ongoing clinical trials are reviewed. PMID:24629039

  3. Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

    Energy Technology Data Exchange (ETDEWEB)

    Abd Ellah, Mohamed, E-mail: dr_m_hamdy2006@hotmail.co [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Kremser, Christian, E-mail: christian.kremser@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pallwein, Leo, E-mail: leo.pallwein-prettner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Aigner, Friedrich, E-mail: friedrich.Aigner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Schocke, Michael, E-mail: michael.schocke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Peschel, Reinhard, E-mail: reinhard.peschel@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pedross, Florian, E-mail: florian.pedross@i-med.ac.a [Innsbruck Medical University, Medical Statistics Dept., Anich St. 35, 6020 Innsbruck (Austria); Pinggera, Germar-Michael, E-mail: germar.pinggera@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Wolf, Christian, E-mail: christian.wolf@bkh-reutte.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Alsharkawy, Mostafa A.M., E-mail: drmostafamri@yahoo.co [Assiut University, Radiology Dept., Assiut (Egypt); Jaschke, Werner, E-mail: werner.jaschke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Frauscher, Ferdinand, E-mail: ferdinand.frauscher@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria)

    2010-10-15

    The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

  4. Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

    International Nuclear Information System (INIS)

    The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

  5. CAD of myocardial perfusion

    Science.gov (United States)

    Storm, Corstiaan J.; Slump, Cornelis H.

    2007-03-01

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

  6. Background suppression in arterial spin labeling MRI with a separate neck labeling coil

    OpenAIRE

    Shen, Qiang; Duong, Timothy Q.

    2011-01-01

    In arterial spin labeling (ASL) MRI to measure cerebral blood flow (CBF), pair-wise subtraction of temporally adjacent non-labeled and labeled images often can not completely cancel the background static tissue signal because of temporally fluctuating physiological noise. While background suppression (BS) by inversion nulling improves CBF temporal stability, imperfect pulses compromise CBF contrast. Conventional BS techniques may not be applicable in small animals because the arterial transit...

  7. Diagnosis of acute stroke by MRI and biomarker

    International Nuclear Information System (INIS)

    Stroke Care Unit (SCU) in Tokushima University Hospital has been opened since November 1999. Patients with acute stroke in SCU were diagnosed by stroke MRI and biomarker immediately after their admission. Diffusion MRI could diagnose the ultra-acute ischemic and hemorrhagic lesion except brainstem ischemic lesion within 3 hrs after onset. Diffusion-Perfusion mismatch was useful to indicate intra-arterial thrombolytic therapy. 3T-MRI was introduced since March 2004, and it can measured functional MR spectroscopy and tractography more quickly compared to 1. 5T-MRI. Plasma oxidized low density lipoprotein (LDL) in patients with acute cerebral infarction was significantly higher than that in healthy control and it became peak level during 3-5 day after stroke onset. In conclusion, stroke MRI and plasma oxidized LDL are useful diagnostic tools for acute stroke. (author)

  8. Battlefield MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  9. An unsupervised approach for measuring myocardial perfusion in MR image sequences

    Science.gov (United States)

    Discher, Antoine; Rougon, Nicolas; Preteux, Francoise

    2005-08-01

    Quantitatively assessing myocardial perfusion is a key issue for the diagnosis, therapeutic planning and patient follow-up of cardio-vascular diseases. To this end, perfusion MRI (p-MRI) has emerged as a valuable clinical investigation tool thanks to its ability of dynamically imaging the first pass of a contrast bolus in the framework of stress/rest exams. However, reliable techniques for automatically computing regional first pass curves from 2D short-axis cardiac p-MRI sequences remain to be elaborated. We address this problem and develop an unsupervised four-step approach comprising: (i) a coarse spatio-temporal segmentation step, allowing to automatically detect a region of interest for the heart over the whole sequence, and to select a reference frame with maximal myocardium contrast; (ii) a model-based variational segmentation step of the reference frame, yielding a bi-ventricular partition of the heart into left ventricle, right ventricle and myocardium components; (iii) a respiratory/cardiac motion artifacts compensation step using a novel region-driven intensity-based non rigid registration technique, allowing to elastically propagate the reference bi-ventricular segmentation over the whole sequence; (iv) a measurement step, delivering first-pass curves over each region of a segmental model of the myocardium. The performance of this approach is assessed over a database of 15 normal and pathological subjects, and compared with perfusion measurements delivered by a MRI manufacturer software package based on manual delineations by a medical expert.

  10. Sign Perception and Recognition in Non-Native Signers of ASL.

    Science.gov (United States)

    Morford, Jill P; Carlson, Martina L

    2011-01-01

    Past research has established that delayed first language exposure is associated with comprehension difficulties in non-native signers of American Sign Language (ASL) relative to native signers. The goal of the current study was to investigate potential explanations of this disparity: do non-native signers have difficulty with all aspects of comprehension, or are their comprehension difficulties restricted to some aspects of processing? We compared the performance of deaf non-native, hearing L2, and deaf native signers on a handshape and location monitoring and a sign recognition task. The results indicate that deaf non-native signers are as rapid and accurate on the monitoring task as native signers, with differences in the pattern of relative performance across handshape and location parameters. By contrast, non-native signers differ significantly from native signers during sign recognition. Hearing L2 signers, who performed almost as well as the two groups of deaf signers on the monitoring task, resembled the deaf native signers more than the deaf non-native signers on the sign recognition task. The combined results indicate that delayed exposure to a signed language leads to an overreliance on handshape during sign recognition. PMID:21686080

  11. DIFFERENCES BETWEEN AMERICAN SIGN LANGUAGE (ASL AND BRITISH SIGN LANGUAGE (BSL

    Directory of Open Access Journals (Sweden)

    Zora JACHOVA

    2008-06-01

    Full Text Available In the communication of deaf people between them­selves and hearing people there are three ba­sic as­pects of interaction: gesture, finger signs and writing. The gesture is a conditionally agreed manner of communication with the help of the hands followed by face and body mimic. The ges­ture and the move­ments pre-exist the speech and they had the purpose to mark something, and later to emphasize the speech expression.Stokoe was the first linguist that realised that the signs are not a whole that can not be analysed. He analysed signs in insignificant parts that he called “chemeres”, and many linguists today call them pho­nemes. He created three main phoneme catego­ries: hand position, location and movement.Sign languages as spoken languages have back­ground from the distant past. They developed par­allel with the development of spoken language and undertook many historical changes. Therefore, to­day they do not represent a replacement of the spoken language, but are languages themselves in the real sense of the word.Although the structures of the English language used in USA and in Great Britain is the same, still their sign languages-ASL and BSL are different.

  12. 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...

  13. Injury and repair in perinatal brain injury: Insights from non-invasive MR perfusion imaging.

    Science.gov (United States)

    Wintermark, Pia

    2015-03-01

    Injury to the developing brain remains an important complication in critically ill newborns, placing them at risk for future neurodevelopment impairments. Abnormal brain perfusion is often a key mechanism underlying neonatal brain injury. A better understanding of how alternations in brain perfusion can affect normal brain development will permit the development of therapeutic strategies that prevent and/or minimize brain injury and improve the neurodevelopmental outcome of these high-risk newborns. Recently, non-invasive MR perfusion imaging of the brain has been successfully applied to the neonatal brain, which is known to be smaller and have lower brain perfusion compared to older children and adults. This article will present an overview of the potential role of non-invasive perfusion imaging by MRI to study maturation, injury, and repair in perinatal brain injury and demonstrate why this perfusion sequence is an important addition to current neonatal imaging protocols, which already include different sequences to assess the anatomy and metabolism of the neonatal brain.

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

    Science.gov (United States)

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

    2014-03-01

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

  15. 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.)

  16. Quantitative evaluation of muscle perfusion with CEUS and with MR

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Marc-Andre; Delorme, Stefan [German Cancer Research Centre, Department of Radiology, Heidelberg (Germany); Krix, Martin [German Cancer Research Centre, Department of Radiology, Heidelberg (Germany); Bracco ALTANA Pharma GmbH, Konstanz (Germany)

    2007-10-15

    Functional imaging might increase the role of imaging in muscular diseases, since alterations of muscle morphology alone are not specific for a particular disease. Perfusion, i.e., the blood flow per tissue and time unit including capillary flow, is an important functional parameter. Pathological changes of skeletal muscle perfusion can be found in various clinical conditions, such as degenerative or inflammatory myopathies or peripheral arterial occlusive disease. This article reviews the theoretical basics of functional radiological techniques for assessing skeletal muscle perfusion and focuses on contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI) techniques. Also, the applications of microvascular imaging, such as in detection of myositis and for discriminating myositis from other myopathies or evaluating peripheral arterial occlusive disease, are presented, and possible clinical indications are discussed. In conclusion, dedicated MR and CEUS methods are now available that visualize and quantify (patho-)physiologic information about microcirculation within skeletal muscles in vivo and hence establish a useful diagnostic tool for muscular diseases. (orig.)

  17. CT perfusion in acute stroke

    International Nuclear Information System (INIS)

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

  18. Dynamic CT myocardial perfusion imaging.

    Science.gov (United States)

    Caruso, Damiano; Eid, Marwen; Schoepf, U Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie; Spandorfer, Adam; Laghi, Andrea; De Cecco, Carlo N

    2016-10-01

    Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  19. Noninvasive methods of measuring bone blood perfusion

    OpenAIRE

    Dyke, J. P.; Aaron, R.K.

    2010-01-01

    Measurement of bone blood flow and perfusion characteristics in a noninvasive and serial manner would be advantageous in assessing revascularization after trauma and the possible risk of avascular necrosis. Many disease states, including osteoporosis, osteoarthritis, and bone neoplasms, result in disturbed bone perfusion. A causal link between bone perfusion and remodeling has shown its importance in sustained healing and regrowth following injury. Measurement of perfusion and permeability wi...

  20. What Is Chest MRI?

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Chest MRI? Chest MRI (magnetic resonance imaging) is a safe, noninvasive test. "Noninvasive" means that ... your chest wall, heart, and blood vessels. Chest MRI uses radio waves, magnets, and a computer to ...

  1. Breast MRI scan

    Science.gov (United States)

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... your stomach on a narrow table with your breasts hanging down into cushioned openings. The table slides ...

  2. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... 8 MB) Also available in Other Language versions . Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making ...

  3. 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.)

  4. 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.)

  5. 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

  6. The study of arterial spin labeling perfusion MR imaging in the patients with subclinical hepatic encephalopathy%动脉自旋标记MRI脑血流灌注成像在亚临床期肝性脑病患者的研究

    Institute of Scientific and Technical Information of China (English)

    杨炯; 韩盈; 崔晓明; 李涛; 周卫华; 马林

    2012-01-01

    Objective To investigate the hemodynamic changes in brain basal ganglia in patients with subclinical hepatic encephalopathy (SHE) using arterial spin labeling (ASL) MRI perfusion technique. Methods 16 patients with SHE diagnosed by neuropsychologic tests and 13 cases education-matched healthy volunteers accepted examinations on 1. 5 T GE MR scanner. The scanning protocol included anatomical images and ASL perfusion MR imaging. Using the function tool perfusion software, the parameter maps of cerebral blood flow (CBF) was created. Bilateral head of caudate nucleus, glo-bus pallidus, putamen, thalamus were selected as regions of interest (ROD. Ipsilateral white matter of frontal lobe was used as reference, the ratios of ROI were calculated and compared with those in the control group. Results The CBF ratio for every ROI was higher in SHE patients versus the control. CBF value of right head of caudate nucleus, globus pallidus, putamen, thalamus versus ipsilateral white matter in frontal lobe in SHE patients was 0. 88±0. 17, 1. 01± 0. 06, 0. 96 ± 0.13 and 0. 93 ±0. 10, respectively, CBF value of left ROI was 0. 91 ± 0. 15, 1.00 ± 0.07, 0. 94±0. 12 and 0.97 ± 0. 11, respectively; and CBF value of right ROI in control group was 0. 81 ± 0. 04, 0. 95 ± 0. 04, 0. 88 ± 0. 04 and 0. 90 ± 0. 04, respectively, CBF value of left ROI in control was 0. 81 ± 0.02, 0. 94 ± 0.04, 0. 87±0. 05 and 0.92 ± 0.04, respectively. Conclusion The increasing CBF in basal ganglia could be identified in patients with SHE using ASL MRI perfusion technique. CBF increase was compatible with the opinion that the cerebral blood flow redistributed from cortical areas to basal ganglion structures.%目的 用动脉自旋标记(ASL)MRI灌注成像技术评价亚临床肝性脑病(SHE)患者基底节区的脑血流灌注模式.方法 对16例经神经心理试验诊断为SHE的患者和13例年龄和教育程度相匹配的健康志愿者进行MRI平扫和ASL灌注成像,分别测量双侧

  7. Incentivi ai farmaci generici a livello di ASL: l’osservatorio I.H.A.G.O.

    Directory of Open Access Journals (Sweden)

    Silvia Martina

    2002-06-01

    Full Text Available Generic drugs are pharmaceutical products that contain an active substance whose patent-covered period expired and are marketed with the name of the molecule. The public health authorities of most EU countries agree on the importance of generic drugs in rationalising the pharmaceutical market, particularly by favouring reasonable pricing of “mature” products. In contrast with this wide consensus, the market share of generic drugs remains quite poor in Italy, despite recent regulatory incentives for the promotion of their use. The longlasting lack of specific laws - reference-price politics were introduced only in 2001- and the unusually long patent-covered period fixed by the past legislation are among the main reasons for the scarce utilisation of generics in Italy. The awareness of the importance of promoting initiatives conducted on a local (ASL, and not only national (SSN scale conducted to the I.H.A.G.O. project, an observatory on the diffusion of generics in several local health districts. The project analyses the impact, in terms of market share, of local promoting activities (investigated by means of questionnaires conducted during the year 2001 in 11 ASLs (local health districts, deliberately selected among the most active in terms of promotion of the use of generics. The I.H.A.G.O. observation revealed several praiseworthy promotional efforts, particularly of informative and cultural kind, conducted by some of the considered ASLs. Unfortunately, these measures seem not to have had a practical impact on the generics market in the observed districts: the market share increase was superior to the one observed on national scale only in 4 of the considered ASLs, in other 4 it was similar, and in the remaining 3 it resulted even inferior. It appears useful to plan further measures to support the diffusion of generics, maybe by motivating health operators to their prescription with the introduction of “prize/punishment” mechanisms.

  8. La sorveglianza delle Tossinfezioni Alimentari nell'ASL Cittá di Milano. Analisi del periodo 1996- 2001

    OpenAIRE

    C. Oggioni; Fontana, G.; Ferraroni, M; Valerio, E; M. Pontello

    2003-01-01

    Obiettivi: descrivere l’epidemiologia delle TA indagate dalle unità operative distrettuali del Servizio di Igiene degli Alimenti e della Nutrizione dell’ASL Città di Milano. Metodi: individuazione di eventi epidemici causati da ingestione di alimenti contaminati con una latenza della sintomatologia gastroenterica inferiore alle 72 ore; raccolta attiva e standardizzata su scheda appositamente configurata dei dati conservati su supporto cartaceo negli archi...

  9. Real-time processing of ASL signs: Delayed first language acquisition affects organization of the mental lexicon.

    Science.gov (United States)

    Lieberman, Amy M; Borovsky, Arielle; Hatrak, Marla; Mayberry, Rachel I

    2015-07-01

    Sign language comprehension requires visual attention to the linguistic signal and visual attention to referents in the surrounding world, whereas these processes are divided between the auditory and visual modalities for spoken language comprehension. Additionally, the age-onset of first language acquisition and the quality and quantity of linguistic input for deaf individuals is highly heterogeneous, which is rarely the case for hearing learners of spoken languages. Little is known about how these modality and developmental factors affect real-time lexical processing. In this study, we ask how these factors impact real-time recognition of American Sign Language (ASL) signs using a novel adaptation of the visual world paradigm in deaf adults who learned sign from birth (Experiment 1), and in deaf adults who were late-learners of ASL (Experiment 2). Results revealed that although both groups of signers demonstrated rapid, incremental processing of ASL signs, only native signers demonstrated early and robust activation of sublexical features of signs during real-time recognition. Our findings suggest that the organization of the mental lexicon into units of both form and meaning is a product of infant language learning and not the sensory and motor modality through which the linguistic signal is sent and received.

  10. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

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

    2014-01-01

    This review summarizes evidence in humans for an association between hyperventilation (HV)-induced hypocapnia and a reduction in cerebral perfusion leading to syncope defined as transient loss of consciousness (TLOC). The cerebral vasculature is sensitive to changes in both the arterial carbon di...

  11. Artificial tissues in perfusion culture.

    Science.gov (United States)

    Sittinger, M; Schultz, O; Keyszer, G; Minuth, W W; Burmester, G R

    1997-01-01

    In the stagnant environment of traditional culture dishes it is difficult to generate long term experiments or artificial tissues from human cells. For this reason a perfusion culture system with a stable supply of nutrients was developed. Human chondrocytes were seeded three-dimensionally in resorbable polymer fleeces. The cell-polymer tissues were then mounted in newly developed containers (W.W. Minuth et al, Biotechniques, 1996) and continuously perfused by fresh medium for 40 days. Samples from the effluate were analyzed daily, and the pH of the medium and glucose concentration remained stable during this period. The lactid acid concentration increased from 0.17 mg/ml to 0.35 mg/ml, which was influenced by the degradation of the resorbable polymer fibers used as three dimensional support material for the cells. This perfusion system proved to be reliable especially in long term cultures. Any components in the culture medium of the cells could be monitored without disturbances as caused by manual medium replacement. These results suggest the described perfusion culture system to be a valuable and convenient tool for many applications in tissue engineering, especially in the generation of artificial connective tissue.

  12. Xenon ventilation and perfusion studies

    International Nuclear Information System (INIS)

    Xenon ventilation and perfusion techniques were developed to view pulmonary function dynamically. Background from previous studies and from the xenon given the patient can interfere with the visual and computer analysis of the data. A computer program was developed to subtract the various background contributions. The protocol for the studies, the computer program and the results are described. (author)

  13. Placental perfusion - a human alternative

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E

    2006-01-01

    Foetal exposures to environmental and medicinal products have impact on the growth of the foetus (e.g. cigarette smoke) and development of organs (e.g. methylmercury and Thalidomide). Perfusion studies of the human term placenta enable investigation of placental transport of chemical substances...

  14. Development of hyperpolarized noble gas MRI

    Science.gov (United States)

    Albert, M. S.; Balamore, D.

    1998-02-01

    Magnetic resonance imaging using the MR signal from hyperpolarized noble gases 129Xe and 3He may become an important new diagnostic technique. Alex Pines (adapting the hyperpolarization technique pioneered by William Happer) presented MR spectroscopy studies using hyperpolarized 129Xe. The current authors recognized that the enormous enhancement in the detectability of 129Xe, promised by hyperpolarization, would solve the daunting SNR problems impeding their attempts to use 129Xe as an in vivo MR probe, especially in order to study the action of general anesthetics. It was hoped that hyperpolarized 129Xe MRI would yield resolutions equivalent to that achievable with conventional 1H 2O MRI, and that xenon's solubility in lipids would facilitate investigations of lipid-rich tissues that had as yet been hard to image. The publication of hyperpolarized 129Xe images of excised mouse lungs heralded the emergence of hyperpolarized noble-gas MRI. Using hyperpolarized 3He, researchers have obtained images of the lung gas space of guinea pigs and of humans. Lung gas images from patients with pulmonary disease have recently been reported. 3He is easier to hyperpolarize than 129Xe, and it yields a stronger MR signal, but its extremely low solubility in blood precludes its use for the imaging of tissue. Xenon, however, readily dissolves in blood, and the T1 of dissolved 129Xe is long enough for sufficient polarization to be carried by the circulation to distal tissues. Hyperpolarized 129Xe dissolved-phase tissue spectra from the thorax and head of rodents and humans have been obtained, as have chemical shift 129Xe images from the head of rats. Lung gas 129Xe images of rodents, and more recently of humans, have been reported. Hyperpolarized 129Xe MRI (HypX-MRI) may elucidate the link between the structure of the lung and its function. The technique may also be useful in identifying ventilation-perfusion mismatch in patients with pulmonary embolism, in staging and tracking the

  15. Demonstration of pulmonary perfusion heterogeneity induced by gravity and lung inflation using arterial spin labeling

    International Nuclear Information System (INIS)

    Objective: To evaluate the effect of gravity and lung inflation on pulmonary perfusion heterogeneity in human lung using an arterial spin labeling (ASL) sequence called flow sensitive alternating inversion recovery (FAIR). Materials and methods: Magnetic resonance imaging of lung perfusion using arterial spin labeling sequence was performed in supine position in ten healthy volunteers on a 1.5 T whole body scanner (GE Healthcare). Five coronal slices at an interval of 3 cm from dorsal to ventral (labeled as P3, P6, P9, P12, P15, sequently) were obtained when the volunteers performed breath holding on end expiration and the relative pulmonary blood flow (rPBF) was measured. Then, another coronal perfusion-weighted image of P3 slice was obtained on end inspiration. Tagging efficiency of pulmonary parenchyma with IR (ΔSI), rPBF and area of the P3 slice were analyzed. Results: (1) Along the direction of gravity, a gradient was visually perceived as a vertical increase in rPBF. There were significant statistic differences in rPBF between any two coronal planes except that between P12 and P15. In supine position, regression coefficients of right and left lung were -4.98 and -5.16, respectively. This means that rPBF decreased 4.98 (right) and 5.16 (left) for each centimeter above the dorsal. No statistical difference was seen between ROIs placed along iso-gravitational plane. (2) For a same slice, there were significant statistic differences in ΔSI, rPBF and area at different respiratory phases (P < 0.05). Greater ΔSI and more perfusion were observed on end expiration than on end inspiration. The area was larger on end inspiration than on end expiration. Conclusion: Both gravity and respiratory phase are important determinants of pulmonary perfusion heterogeneity. FAIR is sensitive to demonstrate gravity- and respiratory phase-dependent differences in lung perfusion. Positioning the patient so that the area of interest is down-gravity and asking patient to hold breath

  16. Demonstration of pulmonary perfusion heterogeneity induced by gravity and lung inflation using arterial spin labeling

    Energy Technology Data Exchange (ETDEWEB)

    Fan Li [Department of Radiology, ChangZheng Hospital, Second Military Medical University, Shanghai 200003 (China)], E-mail: fanli0930@163.com; Liu Shiyuan [Department of Radiology, ChangZheng Hospital, Second Military Medical University, Shanghai 200003 (China)], E-mail: fanli7938@chinaren.com; Xiao Xiangsheng [Department of Radiology, ChangZheng Hospital, Second Military Medical University, Shanghai 200003 (China)], E-mail: lizhaobin79@163.com; Sun Fei [GE Healthcare (China)], E-mail: Fei.sun@med.ge.com

    2010-02-15

    Objective: To evaluate the effect of gravity and lung inflation on pulmonary perfusion heterogeneity in human lung using an arterial spin labeling (ASL) sequence called flow sensitive alternating inversion recovery (FAIR). Materials and methods: Magnetic resonance imaging of lung perfusion using arterial spin labeling sequence was performed in supine position in ten healthy volunteers on a 1.5 T whole body scanner (GE Healthcare). Five coronal slices at an interval of 3 cm from dorsal to ventral (labeled as P3, P6, P9, P12, P15, sequently) were obtained when the volunteers performed breath holding on end expiration and the relative pulmonary blood flow (rPBF) was measured. Then, another coronal perfusion-weighted image of P3 slice was obtained on end inspiration. Tagging efficiency of pulmonary parenchyma with IR ({delta}SI), rPBF and area of the P3 slice were analyzed. Results: (1) Along the direction of gravity, a gradient was visually perceived as a vertical increase in rPBF. There were significant statistic differences in rPBF between any two coronal planes except that between P12 and P15. In supine position, regression coefficients of right and left lung were -4.98 and -5.16, respectively. This means that rPBF decreased 4.98 (right) and 5.16 (left) for each centimeter above the dorsal. No statistical difference was seen between ROIs placed along iso-gravitational plane. (2) For a same slice, there were significant statistic differences in {delta}SI, rPBF and area at different respiratory phases (P < 0.05). Greater {delta}SI and more perfusion were observed on end expiration than on end inspiration. The area was larger on end inspiration than on end expiration. Conclusion: Both gravity and respiratory phase are important determinants of pulmonary perfusion heterogeneity. FAIR is sensitive to demonstrate gravity- and respiratory phase-dependent differences in lung perfusion. Positioning the patient so that the area of interest is down-gravity and asking patient

  17. 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.)

  18. Tall gastrodis tuber combined with antiepileptic drugs repairs abnormal perfusion foci in focal epilepsy

    Institute of Scientific and Technical Information of China (English)

    Weimin Wang; Zhenyu Fan; Yongqin Zhang; Yuxia Yang; Yaqing Liu; Xiaoli Dang; Wenjun Song; Yinping Wu; Jiang Ye

    2013-01-01

    One hundred patients with focal epilepsy were recruited for the present study and their seizures controlled with antiepileptic drugs. The patients then orally received a capsule of tall gastrodis tuber powder, a traditional Chinese drug, and underwent single photon emission computed tomography, long-term electroencephalogram, and CT/MRI. Blood drug levels were monitored throughout the study. Before treatment with tall gastrodis tuber, 35 of the 100 cases had abnormal CT/MRI scans; 79 cases had abnormal single photon emission computed tomography images; 86 cases had abnormal electroencephalogram; and a total of 146 abnormal perfusion foci were observed across the 100 subjects. After treatment, the number of patients with normal single photon emission computed tomography images increased by 12; normal electroencephalogram was observed in an additional 27 cases and the number of patients with epileptiform discharge decreased by 29 (34% of 86); the total number of abnormal perfusion foci decreased by 52 (36%) and changes in abnormal foci were visible in 65 patients. These changes indicate that the administration of tall gastrodis tuber in combination with antiepileptic drugs repairs abnormal perfusion foci in patients with focal epilepsy. Our results demonstrate that traditional Chinese drugs can repair abnormal perfusion foci and, as such, are a promising new pathway in the treatment of focal epilepsy.

  19. Temporal and extra-temporal hypoperfusion in medial temporal lobe epilepsy evaluated by arterialspin-labeling based MRI%内侧颞叶癫痫患者颞叶及颞叶外低灌注的动脉自旋标记MRI

    Institute of Scientific and Technical Information of China (English)

    沈连芳; 谭启富; 张志强; 卢光明; 袁翠平; 王正阁; 王茂雪; 黄巍; 魏方圆; 陈光辉

    2012-01-01

    目的 评价基于动脉自旋标记(ASL)的MRI技术在内侧颞叶癫痫(mTLE)定侧方面的应用价值,探讨mTLE癫痫网络脑区的脑灌注改变及其临床相关情况.方法 选取25例左侧mTLE、23例右侧mTLE患者及30名正常志愿者,通过脉冲式ASL序列技术进行MR扫描,并采集脑血流量(CBF)数据.采用基于体素的方差分析技术,寻找mTLE患者相比正常对照组脑CBF改变的脑区,并分析其与临床病程的相关性.采用基于感兴趣区分析的技术,计算mTLE患者双侧颞叶灌注的偏侧化指数,初步评价其在颞叶癫痫定侧方面的应用价值.结果 与正常对照组相比,mTLE患者表现为双侧颞叶内侧和外侧区域、双侧额顶叶,以及与脑默认模式网络有关的脑区CBF降低,且以患侧为著;患侧颞叶的CBF值与癫痫病程呈负相关(r=-0.51,P<0.01).通过对两组患者CBF值偏侧化指数计算,发现当偏侧化指数值为-0.01时,依据CBF进行mTLE定侧的敏感度为76.0%(19/25)、特异度为78.3%(18/23).结论 基于ASL的MR成像技术揭示mTLE颞叶及颞叶外脑灌注的降低,反映了内侧颞叶癫痫网络功能受损的性质;此技术具有较好的癫痫临床定侧价值.%Objective To evaluate the feasibility of the lateralization of unilateral medial temporal lobe epilepsy(mTLE)by using arterial-spin-labeling(ASL)based perfusion MR imaging and investigate the changes of perfusion in the regions related to mTLE network and the relationship between the perfusion and the clinical status.Methods Twenty-five patients with left-sided and 23 with right-sided mTLE were enroiled,and 30 healthy volunteers were recruited.The cerebral blood flow(CBF)of related region was measured based on pulsed-ASL sequence on Siemens 3 T scanner.The CBF of the mTLE group were compared with that in the controls by using ANOVA analysis.The asymmetric indices of CBF in the medial temporal lobe were calculated as the lesion side compared with the normal

  20. Evaluation of heart perfusion in patients with acute myocardial infarction using dynamic contrast-enhanced magnetic resonance imaging

    DEFF Research Database (Denmark)

    Nielsen, Gitte; Fritz-Hansen, Thomas; Dirks, Christina G;

    2004-01-01

    PURPOSE: To investigate the diagnostic ability of quantitative magnetic resonance imaging (MRI) heart perfusion in acute heart patients, a fast, multislice dynamic contrast-enhanced MRI sequence was applied to patients with acute myocardial infarction. MATERIALS AND METHODS: Seven patients...... with acute transmural myocardial infarction were studied using a Turbo-fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five...... acutely ill patients following acute myocardial infarction. The technique provides information on both the volume and severity of affected myocardial tissue, enabling the power of treatment regimes to be assessed objectively, and this approach should aid individual patient stratification and prognosis...

  1. Incidenza di meningiti nell'ASL di Brescia nei primi mesi del 2003

    Directory of Open Access Journals (Sweden)

    M. Magoni

    2003-05-01

    Full Text Available

    Obiettivi: nell’ASLdi Brescia durante i mesi di gennaiomaggio 2003 si è verificato un consistente aumento di casi di meningite che ha allarmato oltre agli operatori sanitari anche l’opinione pubblica locale.

    Metodi: i dati riguardanti i casi di meningite verificatisi dal gennaio 1999 al maggio 2003 sono stati raccolti dal Servizio Igiene Pubblica dell’ASLdi Brescia.

    Tenuto conto della omogeneità dei dati nel quadriennio 1999- 2002 e della stagionalità che le meningiti possono avere, sono stati calcolati i tassi di incidenza per i primi cinque mesi dell’anno per tutte le meningiti in generale e per agente eziologico, durante il quadriennio 1999-2002. Tali tassi sono stati confrontati con i tassi corrispondenti nei primi mesi del 2003.

    Risultati: nel primi 5 mesi del 2003 si sono registrati in tutto 48 casi, di cui 9 da meningocco, 13 da pneumococco, 14 virali, 3 da altri agenti batterici e 8 senza agente microbico identificato. Nei 4 anni precedenti erano stati notificati 66 casi di meningite nei primi 5 mesi dell’anno, con una media annua di 16.5. Il tasso di incidenza di meningite in gennaio-maggio è stato quindi il triplo nel 2003 (rischio relativo = 2.9 rispetto ai 4 anni precedenti (p=0.0001. L’eccesso di incidenza si è riscontrato per tutti i tipi di meningite considerati in base all’agente eziologico.

    L’analisi per diverse età ha mostrato un aumento di incidenza sia nei bambini che nei giovani adulti e negli anziani. Non si è riscontrata alcuna differenza statisticamente significativa tra l’incidenza nel comune di Brescia (area urbana rispetto all’intera ASL nel periodo in studio.

    Conclusioni: l’aumento di incidenza per meningiti
    osservato nel 2003 non sembra spiegabile in termini di variabilità casuale del fenomeno da un anno all’altro e riguarda tutti i tipi di meningite e tutte le categorie d

  2. Vaccinazione antinfluenzale nella ASL RMF della Regione Lazio: verifica dei risultati e dei costi sostenuti

    Directory of Open Access Journals (Sweden)

    L. Di Marzio

    2003-05-01

    Full Text Available

    Obiettivi: la vaccinazione antinfluenzale nella
    Regione Lazio dalla campagna 1999-2000 viene
    condotta sulla base di un protocollo regionale che,
    per favorire il raggiungimento degli obiettivi stabiliti
    dal Piano Sanitario Nazionale, coinvolge i
    Medici di Medicina Generale (MMG prevedendo
    una remunerazione aggiuntiva in parte fissa (a prestazione, in parte variabile (condizionata dal risultato
    del singolo medico e della ASL.
    Gli autori si propongono una verifica dei risultati raggiunti e dei costi sostenuti dall’ultima campagna eseguita con sole risorse aziendali del 1998-99 a quella del 2002-03.

    Metodi: il protocollo regionale prevede la raccolta
    delle informazioni per ciascun vaccinato presente
    nell’anagrafe informatizzata degli assistiti aziendali
    e ciò consente la valutazione delle coperture vaccinali
    aziendale e per ciascun MMG.
    Parallelamente sono considerati costi dei vaccini
    acquistati e retribuzione aggiuntiva dei MMG.

    Risultati: esaminati gli archivi dal 1998-99 al 2002-
    03, emerge il progressivo coinvolgimento dei MMG fino al recente 97%, l’aumento inequivocabile delle dosi di vaccino somministrate (da 9.406 a 36.692 e del tasso di copertura negli anziani (dal 24,2% al 66%. Invece la percentuale dei vaccini somministrati ai ›65 diminuisce dal 85,47% al 71,77% ed aumenta a favore dei più giovani così da risultare coperture negli ultrasessantacinquenni inferiori alle attese.Con gli anni l’integrazione dell’esperienza del servizio e dei MMG ha favorito un più oculato approvvigionamento
    con diminuzione degli sprechi passando dal 15,56% nel 2000-01 all’attuale 4,45%, ma contestualmente i costi risultano decuplicati (da 90 a 938 milioni di lire per maggior numero di dosi somministrate e costo delle prestazioni dei MMG

  3. Nonconventional MRI and microstructural cerebral changes in multiple sclerosis

    DEFF Research Database (Denmark)

    Enzinger, Christian; Barkhof, Frederik; Ciccarelli, Olga;

    2015-01-01

    MRI has become the most important paraclinical tool for diagnosing and monitoring patients with multiple sclerosis (MS). However, conventional MRI sequences are largely nonspecific in the pathology they reveal, and only provide a limited view of the complex morphological changes associated with MS....... Nonconventional MRI techniques, such as magnetization transfer imaging (MTI), diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) promise to complement existing techniques by revealing more-specific information on microstructural tissue changes. Past years have witnessed dramatic advances...... in the acquisition and analysis of such imaging data, and numerous studies have used these tools to probe tissue alterations associated with MS. Other MRI-based techniques-such as myelin-water imaging, (23)Na imaging, magnetic resonance elastography and magnetic resonance perfusion imaging-might also...

  4. 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.)

  5. Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Magnetic Resonance Imaging (MRI) KidsHealth > For Teens > Magnetic Resonance Imaging (MRI) Print A A A Text Size What's ... Exam Safety Getting Your Results What Is MRI? Magnetic resonance imaging (MRI) is a type of safe, painless testing ...

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

    OpenAIRE

    Galazzo, I. B.; Mattoli, M. V.; Pizzini, F. B.; Vita, E.; Barnes, A.; Duncan, J.S.; Jager, R.; Golay, X.; Bomanji, J. B.; Koepp, M.; Groves, A M; Fraioli, F.

    2016-01-01

    The major challenge in pre-surgical epileptic patient evaluation is the correct identification of the seizure onset area, especially in MR-negative patients. In this study, we aimed to: (1) assess the concordance between perfusion, from ASL, and metabolism, from 18F-FDG, acquired simultaneously on PET/MR; (2) verify the utility of a statistical approach as supportive diagnostic tool for clinical readers. Secondarily, we compared 18F-FDG PET data from the hybrid PET/MR system with those acquir...

  7. 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.

  8. Feasibility study of CT perfusion imaging for prostate carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cullu, Nesat [Mugla Sitki Kocman University, School of Medicine, Department of Radiology, Mugla (Turkey); Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Kantarci, Mecit; Ogul, Hayri; Pirimoglu, Berhan; Karaca, Leyla; Kizrak, Yesim [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Adanur, Senol; Koc, Erdem; Polat, Ozkan [Atatuerk University, School of Medicine, Department of Urology, Erzurum (Turkey); Okur, Aylin [Atatuerk University, School of Medicine, Department of Radiology, Erzurum (Turkey); Bozok University, School of Medicine, Department of Radiology, Yozgat (Turkey)

    2014-09-15

    The aim of this feasibility study was to obtain initial data with which to assess the efficiency of perfusion CT imaging (CTpI) and to compare this with magnetic resonance imaging (MRI) in the diagnosis of prostate carcinoma. This prospective study involved 25 patients with prostate carcinoma undergoing MRI and CTpI. All analyses were performed on T2-weighted images (T2WI), apparent diffusion coefficient (ADC) maps, diffusion-weighted images (DWI) and CTp images. We compared the performance of T2WI combined with DWI and CTp alone. The study was approved by the local ethics committee, and written informed consent was obtained from all patients. Tumours were present in 87 areas according to the histopathological results. The diagnostic performance of the T2WI+DWI+CTpI combination was significantly better than that of T2WI alone for prostate carcinoma (P < 0.001). The diagnostic value of CTpI was similar to that of T2WI+DWI in combination. There were statistically significant differences in the blood flow and permeability surface values between prostate carcinoma and background prostate on CTp images. CTp may be a valuable tool for detecting prostate carcinoma and may be preferred in cases where MRI is contraindicated. If this technique is combined with T2WI and DWI, its diagnostic value is enhanced. (orig.)

  9. 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.)

  10. 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.)

  11. Learning approach to analyze tumour heterogeneity in DCE-MRI data during anti-cancer treatment

    OpenAIRE

    Daducci, Alessandro; Castellani, Umberto; Cristani, Marco; Farace, Paolo; Marzola, Pasquina; Sbarbati, Andrea; Murino, Vittorio

    2009-01-01

    The paper proposes a learning approach to support medical researchers in the context of in-vivo cancer imaging, and specifically in the analysis of Dynamic Contrast-Enhanced MRI (DCE-MRI) data. Tumour heterogeneity is characterized by identifying regions with different vascular perfusion. The overall aim is to measure volume differences of such regions for two experimental groups: the treated group, to which an anticancer therapy is administered, and a control group. The proposed approach is ...

  12. New insights on COPD imaging via CT and MRI

    OpenAIRE

    Sverzellati, N; Molinari, F.; PIRRONTI, T.; Bonomo, L.; Spagnolo, P.; Zompatori, M.

    2007-01-01

    Multidetector-row computed tomography (MDCT) can be used to quantify morphological features and investigate structure/function relationship in COPD. This approach allows a phenotypical definition of COPD patients, and might improve our understanding of disease pathogenesis and suggest new therapeutical options. In recent years, magnetic resonance imaging (MRI) has also become potentially suitable for the assessment of ventilation, perfusion and respiratory mechanics. This review focuses on th...

  13. 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.)

  14. Ex vivo lung graft perfusion.

    Science.gov (United States)

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

    2016-04-01

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

  15. 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)

  16. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-01

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

  18. 20 years of surface ozone measurements at El Tololo, Chile (2200 m asl)

    Science.gov (United States)

    Gérard Anet, Julien; Steinbacher, Martin; Emmenegger, Lukas; Buchmann, Brigitte

    2016-04-01

    Globally consistent in situ-observations of high precision and known quality are one key element in understanding global climate change and effects of human activity on the Earth's atmosphere. The spatial coverage of available data strongly depends on the species of interest and varies highly around the globe. In case of surface ozone (O3), the observational network is particularly sparse in Africa, Asia, and South America. The southern hemispheric pristine GAW-regional station "El Tololo", located in the foothills of the Chilean Andes (30.17° S, 70.80° W, 2220 m asl), has been equipped with an ozone photometer in 1995 and has since then been measuring tropospheric ozone permanently. However, these measurements were neither entirely systematically processed nor quality-controlled until recently. This situation was drastically improved in 2015 the framework of the Capacity Building and Twinning for Climate Observing Systems (CATCOS) project (www.meteoswiss.ch/catcos). Empa, in coordination with the local operator, Dirección Meteorológica de Chile (DMC), and the University of Santiago, revised the entire surface ozone measurements. The unique 20-year-long ozone data-set has been made publicly available on the World Data Centre for Greenhouse Gases (WDCGG, Japan) in mid-2015 and represents an exceptional piece of information on the southern hemispheric surface ozone distribution. In contrary to northern hemispheric stations, the positive trend in the measurements of tropospheric ozone at "El Tololo" did not level off in the recent past. More specifically, "El Tololo" shows a steady positive trend of 0.7 ppb/decade in agreement with other stations on the Southern hemisphere. However, the seasonal cycle differs strongly in behaviour, as maximum values in ozone do not peak in austral winter, but in austral spring - most probably due to stratospheric influence. We also find that the spring maximum has a retrograding tendency of around 5 days per decade. A combined

  19. MRI characterization of brown adipose tissue in obese and normal-weight children

    International Nuclear Information System (INIS)

    Brown adipose tissue (BAT) is identified in mammals as an adaptive thermogenic organ for modulation of energy expenditure and heat generation. Human BAT may be primarily composed of brown-in-white (BRITE) adipocytes and stimulation of BRITE may serve as a potential target for obesity interventions. Current imaging studies of BAT detection and characterization have been mainly limited to PET/CT. MRI is an emerging application for BAT characterization in healthy children. To exploit Dixon and diffusion-weighted MRI methods to characterize cervical-supraclavicular BAT/BRITE properties in normal-weight and obese children while accounting for pubertal status. Twenty-eight healthy children (9-15 years old) with a normal or obese body mass index participated. MRI exams were performed to characterize supraclavicular adipose tissues by measuring tissue fat percentage, T2*, tissue water mobility, and microvasculature properties. We used multivariate linear regression models to compare tissue properties between normal-weight and obese groups while accounting for pubertal status. MRI measurements of BAT/BRITE tissues in obese children showed higher fat percentage (P < 0.0001), higher T2* (P < 0.0001), and lower diffusion coefficient (P = 0.015) compared with normal-weight children. Pubertal status was a significant covariate for the T2* measurement, with higher T2* (P = 0.0087) in pubertal children compared to prepubertal children. Perfusion measurements varied by pubertal status. Compared to normal-weight children, obese prepubertal children had lower perfusion fraction (P = 0.003) and pseudo-perfusion coefficient (P = 0.048); however, obese pubertal children had higher perfusion fraction (P = 0.02) and pseudo-perfusion coefficient (P = 0.028). This study utilized chemical-shift Dixon MRI and diffusion-weighted MRI methods to characterize supraclavicular BAT/BRITE tissue properties. The multi-parametric evaluation revealed evidence of morphological differences in brown

  20. MRI characterization of brown adipose tissue in obese and normal-weight children

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jie; Rigsby, Cynthia K.; Shore, Richard M. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, 225 E. Chicago Ave., Box 9, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Schoeneman, Samantha E. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, 225 E. Chicago Ave., Box 9, Chicago, IL (United States); Zhang, Huiyuan [John H. Stroger, Jr. Hospital of Cook County, Collaborative Research Unit, Chicago, IL (United States); Kwon, Soyang [Ann and Robert H. Lurie Children' s Hospital of Chicago, Stanley Manne Children' s Research Institute, Chicago, IL (United States); Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States); Josefson, Jami L. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Division of Endocrinology, Chicago, IL (United States); Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States)

    2015-10-15

    Brown adipose tissue (BAT) is identified in mammals as an adaptive thermogenic organ for modulation of energy expenditure and heat generation. Human BAT may be primarily composed of brown-in-white (BRITE) adipocytes and stimulation of BRITE may serve as a potential target for obesity interventions. Current imaging studies of BAT detection and characterization have been mainly limited to PET/CT. MRI is an emerging application for BAT characterization in healthy children. To exploit Dixon and diffusion-weighted MRI methods to characterize cervical-supraclavicular BAT/BRITE properties in normal-weight and obese children while accounting for pubertal status. Twenty-eight healthy children (9-15 years old) with a normal or obese body mass index participated. MRI exams were performed to characterize supraclavicular adipose tissues by measuring tissue fat percentage, T2*, tissue water mobility, and microvasculature properties. We used multivariate linear regression models to compare tissue properties between normal-weight and obese groups while accounting for pubertal status. MRI measurements of BAT/BRITE tissues in obese children showed higher fat percentage (P < 0.0001), higher T2* (P < 0.0001), and lower diffusion coefficient (P = 0.015) compared with normal-weight children. Pubertal status was a significant covariate for the T2* measurement, with higher T2* (P = 0.0087) in pubertal children compared to prepubertal children. Perfusion measurements varied by pubertal status. Compared to normal-weight children, obese prepubertal children had lower perfusion fraction (P = 0.003) and pseudo-perfusion coefficient (P = 0.048); however, obese pubertal children had higher perfusion fraction (P = 0.02) and pseudo-perfusion coefficient (P = 0.028). This study utilized chemical-shift Dixon MRI and diffusion-weighted MRI methods to characterize supraclavicular BAT/BRITE tissue properties. The multi-parametric evaluation revealed evidence of morphological differences in brown

  1. Ultrasound perfusion signal processing for tumor detection

    Science.gov (United States)

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

    2016-04-01

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

  2. Ventilation-perfusion scintigram in diabetics

    International Nuclear Information System (INIS)

    We carried out ventilation and perfusion scintigraphies and pulmonary function tests in 20 diabetics under 50 years of age. 99mTc-MAA perfusion scintigrams showed evidence of minimal nonuniformity (MNU) in four cases (20%) and nonsegmental defect (NSD) in eight cases (40%). There was a ventilation defect in the single-breath image in one case (5%) and a delayed washout in three cases (15%) upon 133Xe ventilation scintigram. In the NSD group, the mean diffusing capacity value was abnormally low and the mean duration of the diabetes was long compared with other groups. The frequency of perfusion defects was higher than that of ventilation abnormalities; moreover, abnormal findings on ventilation scintigrams were very mild compared with those of perfusion defects. Perfusion defects correlated significantly with a decrease in diffusing capacity. These findings suggest that the disturbance in pulmonary arterial perfusion caused a decrease in diffusing capacity in diabetics. (author)

  3. Ten Years of Black Carbon Measurements in the North Atlantic at the Pico Mountain Observatory, Azores (2225m asl).

    OpenAIRE

    Kumar, Sumit; Fialho, Paulo; Mazzoleni, Lynn R.; Olsen, Seth C.; Owen, R. Chris; Helmig, Detlev; Hueber, Jacques; Dziobak, Michael P.; Kramer, Louisa; Mazzoleni, Claudio

    2012-01-01

    45th annual Fall Meeting, AGU. San Francisco, California, 3-7 December. The Pico Mountain Observatory is located in the summit caldera of the Pico mountain, an inactive volcano on the Pico Island in the Azores, Portugal (38.47°N, 28.40°W, Altitude 2225m asl). The Azores are often impacted by polluted outflows from the North American continent and local sources have been shown to have a negligible influence at the observatory. The value of the station stems from the fact that this is the on...

  4. Diode pumped neodymium doped ASL (Sr1-xLax-yNdyMgxAl12-xO19) laser

    Science.gov (United States)

    Zheng, Lihe; Loiseau, Pascal; Aka, Gérard

    2013-07-01

    Blue laser based on Neodymium doped strontium lanthanum magnesium aluminoxide (Sr1-xLax-yNdyMgxAl12-xO19) single crystal were constructed by second harmonic generation. Output power of 1.72 W at 900nm was obtained under 792nm laser diode pump. Intra cavity second harmonic generation were performed with non linear crystal LBO leading to output power of 76.6 mW at 450nm with absorbed power of 13.7 W and average absorption efficiency of 61% in Nd:ASL crystal.

  5. Reproducibility of rest and exercise stress contrast-enhanced calf perfusion magnetic resonance imaging in peripheral arterial disease

    Directory of Open Access Journals (Sweden)

    Jiji Ronny S

    2013-01-01

    Full Text Available Abstract Background The purpose was to determine the reproducibility and utility of rest, exercise, and perfusion reserve (PR measures by contrast-enhanced (CE calf perfusion magnetic resonance imaging (MRI of the calf in normal subjects (NL and patients with peripheral arterial disease (PAD. Methods Eleven PAD patients with claudication (ankle-brachial index 0.67 ±0.14 and 16 age-matched NL underwent symptom-limited CE-MRI using a pedal ergometer. Tissue perfusion and arterial input were measured at rest and peak exercise after injection of 0.1 mM/kg of gadolinium-diethylnetriamine pentaacetic acid (Gd-DTPA. Tissue function (TF and arterial input function (AIF measurements were made from the slope of time-intensity curves in muscle and artery, respectively, and normalized to proton density signal to correct for coil inhomogeneity. Perfusion index (PI = TF/AIF. Perfusion reserve (PR = exercise TF/ rest TF. Intraclass correlation coefficient (ICC was calculated from 11 NL and 10 PAD with repeated MRI on a different day. Results Resting TF was low in NL and PAD (mean ± SD 0.25 ± 0.18 vs 0.35 ± 0.71, p = 0.59 but reproducible (ICC 0.76. Exercise TF was higher in NL than PAD (5.5 ± 3.2 vs. 3.4 ± 1.6, p = 0.04. Perfusion reserve was similar between groups and highly variable (28.6 ± 19.8 vs. 42.6 ± 41.0, p = 0.26. Exercise TF and PI were reproducible measures (ICC 0.63 and 0.60, respectively. Conclusion Although rest measures are reproducible, they are quite low, do not distinguish NL from PAD, and lead to variability in perfusion reserve measures. Exercise TF and PI are the most reproducible MRI perfusion measures in PAD for use in clinical trials.

  6. Arterial spin labelling in imaging of renal diseases and renal allograft pathology; MRT-Perfusionsmessung mit Arterial Spin Labelling. Anwendung fuer die Niere und Transplantatniere

    Energy Technology Data Exchange (ETDEWEB)

    Hueper, Katja; Gutberlet, Marcel [Medizinische Hochschule Hannover (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Kuehn, Bernd [Siemens AG/Siemens Healthcare GmbH, Erlangen (Germany)

    2016-06-15

    Arterial Spin Labelling (ASL) is a technique for non-invasive and contrast-free assessment of perfusion with MRI. Renal ASL allows examination of renal pathophysiology, evaluation of the course of renal disease and therapy effects by longitudinal measurements as well as characterization of renal tumors. In this article, techniques of ASL will be explained and challenges of renal ASL will be emphasized. In addition, examples for clinical application of ASL for diagnosis of renal disease and renal allograft pathology will be given.

  7. Magnetic resonance imaging in familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion and cardiac enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Tsunehiko; Nagata, Seiki; Sakakibara, Hiroshi

    1988-05-01

    Gated magnetic resonance imaging (MRI) was performed in 6 patients with familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion, and 12 patients with ordinary hypertrophic cardiomyopathy. The patients with ordinary hypertrophic cardiomyopathy and abnormal thickening of the septal wall and normal left ventricular dimensions, while the patients with familial hypertrophic cardiomyopathy had focal wall thinning (usually involving the apical-septal wall) and dilated left ventricle in addition to hypertrophied heart. The quantitative measurement for cardiac dimensions using MRI was similar to that found on echocardiography in all cases. In addition, inhomogeneous signal intensities at left ventricular wall were observed in 3 cases of familial hypertrophic cardiomyopathy, which may suggest the existence of myocardial fibrosis. Gated MRI should be performed for early detection and follow-up of hypertrophic cardiomyopathy, since some patients will progress from hypertrophic cardiomyopathy to dilated cardiomyopathy.

  8. Arterial spin-labeling MR imaging in moyamoya disease compared with clinical assessments and other MR imaging finings

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Tomoyuki, E-mail: tnogucci@radiol.med.kyushu-u.ac.jp [Department of Radiology, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Kawashima, Masatou [Department of Neurosurgery, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Nishihara, Masashi; Hirai, Tetsuyoshi [Department of Radiology, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Matsushima, Toshio [Department of Neurosurgery, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan); Irie, Hiroyuki [Department of Radiology, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga 849-8501 (Japan)

    2013-12-01

    Purpose: Our purpose was to identify the causal factors for the perfusion distribution obtained with ASL-MRI by comparing ASL-MRI with clinical information and other MRI findings in moyamoya disease. Methods: Seventy-one patients with moyamoya disease underwent ASL-MRI and other MRI, including fluid-attenuated inversion recovery imaging (FLAIR) and three-dimensional time-of-flight magnetic resonance angiography (MRA) on 3.0-Tesla MRI system. Cerebral blood flow (CBF) values (ASL values) for the cerebral hemispheres (142 sides) were measured on CBF maps generated by ASL-MRI. Relationships between the ASL values and the following 9 factors were assessed: sex, family history, revascularization surgery, age at MR exam, age at onset, the steno-occlusive severity on MRA (MRA score), degree of basal collaterals, degree of leptomeningeal high signal intensity seen on FLAIR, and size of ischemic or hemorrhagic cerebrovascular accident lesion (CVA score). Results: Patients with a family history had significantly higher ASL values than those without such a history. There were significant negative correlations between ASL values and age at MR exam, MRA score, and CVA score. Conclusions: ASL-MRI may have cause-and-effect or mutual associations with family history, current patient age, size of CVA lesion, and intracranial arterial steno-occlusive severity in Moyamoya disease.

  9. MRI in multiple myeloma: a pictorial review of diagnostic and post-treatment findings.

    Science.gov (United States)

    Dutoit, Julie C; Verstraete, Koenraad L

    2016-08-01

    Magnetic resonance imaging (MRI) is increasingly being used in the diagnostic work-up of patients with multiple myeloma. Since 2014, MRI findings are included in the new diagnostic criteria proposed by the International Myeloma Working Group. Patients with smouldering myeloma presenting with more than one unequivocal focal lesion in the bone marrow on MRI are considered having symptomatic myeloma requiring treatment, regardless of the presence of lytic bone lesions. However, bone marrow evaluation with MRI offers more than only morphological information regarding the detection of focal lesions in patients with MM. The overall performance of MRI is enhanced by applying dynamic contrast-enhanced MRI and diffusion weighted imaging sequences, providing additional functional information on bone marrow vascularization and cellularity.This pictorial review provides an overview of the most important imaging findings in patients with monoclonal gammopathy of undetermined significance, smouldering myeloma and multiple myeloma, by performing a 'total' MRI investigation with implications for the diagnosis, staging and response assessment. Main message • Conventional MRI diagnoses multiple myeloma by assessing the infiltration pattern. • Dynamic contrast-enhanced MRI diagnoses multiple myeloma by assessing vascularization and perfusion. • Diffusion weighted imaging evaluates bone marrow composition and cellularity in multiple myeloma. • Combined morphological and functional MRI provides optimal bone marrow assessment for staging. • Combined morphological and functional MRI is of considerable value in treatment follow-up. PMID:27164915

  10. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does ... What is MRI and how does it work? Magnetic resonance imaging, or MRI, is a way of obtaining very ...

  11. 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

  12. Abdominal MRI scan

    Science.gov (United States)

    Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen ... spread. This is called staging. MRI avoids the dangers of angiography , such as too much radiation exposure ...

  13. MRI of the Chest

    Science.gov (United States)

    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  14. Interventional MRI: update

    Energy Technology Data Exchange (ETDEWEB)

    Lufkin, R.B. [Department of Radiology, University of California Los Angeles, School of Medicine, 10 833 Le Comte Avenue, Los Angeles, CA 90024-1721 (United States); Gronemeyer, D.H.W.; Seibel, R.M.M. [Institute of Diagnostic and Interventional Radiology, Medical Computerscience, University Witten/Herdecke (Germany)

    1997-12-31

    Interventional MRI is in its early stages of development. Nevertheless, the design of new interventional MRI scanners that allow maximum direct access to the patient combined with the development of new interventional MRI pulse sequences and localization systems, means that the archetypal operating rooms of the 21st century may well contain dedicated interventional MRI units for combined radiological and surgical procedures. The present article looks at the state of interventional MRI today and looks ahead to what may be forthcoming in the not-too-distant future. After briefly discussing the instrumentation necessary for practical interventional MRI, the article will go on to describe a number of different approaches to, and clinical applications for, interventional MRI. The use of MRI in guiding and controlling tumor ablation, aspiration cytology and surgical biopsy of different body parts is described. (orig.) With 13 figs., 1 tab., 114 refs.

  15. Quantitative evaluation of MR perfusion imaging using blood pool contrast agent in subjects without pulmonary diseases and in patients with pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Hansch, Andreas; Hinneburg, Uta [University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Jena (Germany); University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Gera (Germany); Kohlmann, Peter; Laue, Hendrik [Fraunhofer MEVIS - Institute for Medical Image Computing, Bremen (Germany); Boettcher, Joachim [SRH Klinikum Gera, Institute of Diagnostic and Interventional Radiology, Gera (Germany); Malich, Ansgar [Suedharzkrankenhaus Nordhausen, Institute of Diagnostic and Interventional Radiology, Nordhausen (Germany); Wolf, Gunter [University Hospital Jena, Department of Internal Medicine III, Jena (Germany); Pfeil, Alexander [University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Jena (Germany); University Hospital Jena, Institute of Diagnostic and Interventional Radiology II, Gera (Germany); University Hospital Jena, Department of Internal Medicine III, Jena (Germany)

    2012-08-15

    To assess the feasibility of time-resolved parallel three-dimensional magnetic resonance imaging (MRI) for quantitative analysis of pulmonary perfusion using a blood pool contrast agent. Quantitative perfusion analysis was performed using novel software to assess pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) in a quantitative manner. The evaluation of lung perfusion in the normal subjects showed an increase of PBF, PBV ventrally to dorsally (gravitational direction), and the highest values at the upper lobe, with a decrease to the middle and lower lobe (isogravitational direction). MTT showed no relevant changes in either the gravitational or isogravitational directions. In comparison with normally perfused lung areas (in diseased patients), the pulmonary embolism (PE) regions showed a significantly lower mean PBF (20 {+-} 0.6 ml/100 ml/min, normal region 94 {+-} 1 ml/100 ml/min; P < 0.001), mean PBV (2 {+-} 0.1 ml/100 ml, normal region 9.8 {+-} 0.1 ml/100 ml; P < 0.001) and mean MTT (3.8 {+-} 0.1 s; normal region 6.3 {+-} 0.1; P < 0.001). Our results demonstrate the feasibility of using time-resolved dynamic contrast-enhanced MRI to determine normal range and regional variation of pulmonary perfusion and perfusion deficits in patients with PE. (orig.)

  16. Perfusion impairments in children with reactive attachment disorder (RAD) on {sup 99m}Tc-ECD brain SPECT: comparison with MR findings

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y. H.; Sin, E. J.; Cheon, K. A.; Yoon, M. J.; Lee, J. D. [Yonsei University College of Medicine, Seoul (Korea, Republic of); Jeon, T. J. [Pochon CHA University College of Medicine, Pochon (Korea, Republic of)

    2002-07-01

    This study aimed to reveal that severe disturbance of attachment relationship with primary care-giver can affect functional and anatomical brain development by measuring cerebral perfusion on {sup 99m}Tc-ECD brain SPECT and correlative MRI. We included 18 children aged 31 to 76 months who met the diagnostic criteria of RAD as defined in DSM-IV and ICD-10 and SSP and CARS. {sup 99m}Tc-ECD SPECT was performed using CERASPECT. MRI was performed in all patients. SPECT data were visually assessed. 15 of 18 children had abnormal perfusion on SPECT, revealing decreased perfusion of Lt.thalamus (7/15) and Rt.thalamus (3/15), and bilateral thalami (5/15). Perfusion of basal ganglia was decreased in 8 children. Decreased perfusion of Lt. parietal area was seen in 2. Whereas, all patients had normal MR findings. Perfusion abnormalities involving thalamus, BG in most children with RAD were found in this study. These results suggest that brain development of infant could be impeded by severe pathologic care and early nurturing environment would be important for normal development.

  17. Quantitative evaluation of MR perfusion imaging using blood pool contrast agent in subjects without pulmonary diseases and in patients with pulmonary embolism

    International Nuclear Information System (INIS)

    To assess the feasibility of time-resolved parallel three-dimensional magnetic resonance imaging (MRI) for quantitative analysis of pulmonary perfusion using a blood pool contrast agent. Quantitative perfusion analysis was performed using novel software to assess pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) in a quantitative manner. The evaluation of lung perfusion in the normal subjects showed an increase of PBF, PBV ventrally to dorsally (gravitational direction), and the highest values at the upper lobe, with a decrease to the middle and lower lobe (isogravitational direction). MTT showed no relevant changes in either the gravitational or isogravitational directions. In comparison with normally perfused lung areas (in diseased patients), the pulmonary embolism (PE) regions showed a significantly lower mean PBF (20 ± 0.6 ml/100 ml/min, normal region 94 ± 1 ml/100 ml/min; P < 0.001), mean PBV (2 ± 0.1 ml/100 ml, normal region 9.8 ± 0.1 ml/100 ml; P < 0.001) and mean MTT (3.8 ± 0.1 s; normal region 6.3 ± 0.1; P < 0.001). Our results demonstrate the feasibility of using time-resolved dynamic contrast-enhanced MRI to determine normal range and regional variation of pulmonary perfusion and perfusion deficits in patients with PE. (orig.)

  18. Evaluating automated dynamic contrast enhanced wrist 3T MRI in healthy volunteers

    DEFF Research Database (Denmark)

    Rastogi, Anshul; Kubassova, Olga; Krasnosselskaia, Lada V;

    2013-01-01

    Dynamic contrast enhanced (DCE)-MRI has great potential to provide quantitative measure of inflammatory activity in rheumatoid arthritis. There is no current benchmark to establish the stability of signal in the joints of healthy subjects when imaged with DCE-MRI longitudinally, which is crucial so...... as to differentiate changes induced by treatment from the inherent variability of perfusion measures. The objective of this study was to test a pixel-by-pixel parametric map based approach for analysis of DCE-MRI (Dynamika) and to investigate the variability in signal characteristics over time in...

  19. Long term perfusion system supporting adipogenesis.

    Science.gov (United States)

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

    2015-08-01

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

  20. Personality factors correlate with regional cerebral perfusion.

    Science.gov (United States)

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

    2006-06-01

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

  1. Computed Tomography (CT) Perfusion in Abdominal Cancer

    DEFF Research Database (Denmark)

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten;

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

  2. Sumatriptan and cerebral perfusion in healthy volunteers.

    Science.gov (United States)

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

    1992-04-01

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

  3. 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

  4. Getting an MRI

    Medline Plus

    Full Text Available ... Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed ...

  5. Getting an MRI

    Science.gov (United States)

    ... Snowboarding, Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en ... Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  6. Getting an MRI

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en ... Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  7. MRI in acute poliomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Kornreich, L. [Imaging Department, The Schneider Children`s Medical Centre of Israel, Kaplan Street, Petah Tiqva 49202 (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Dagan, O. [The Intensive Care Unit, The Schneider Children`s Medical Centre of Israel, Beilinson Medical Campus, Petah Tiqva (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Grunebaum, M. [Imaging Department, The Schneider Children`s Medical Centre of Israel, Kaplan Street, Petah Tiqva 49202 (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

    1996-05-01

    MRI can be used in the diagnosis of anterior horn infection and for assessing the extent of disease. There are no specific MRI signs to differentiate between the various possible pathogens. This is demonstrated in the present case of poliomyelitis, in which MRI of the spine played an important role in establishing the diagnosis. (orig.). With 1 fig.

  8. fMRI Neuroinformatics

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Christensen, Mark Schram; Madsen, Kristoffer M.;

    2006-01-01

    Functional magnetic resonance imaging (fMRI) generates vast amounts of data. The handling, processing, and analysis of fMRI data would be inconceivable without computer-based methods. fMRI neuroinformatics is concerned with research, development, and operation of these methods. Reconstruction...

  9. [Assessing myocardial perfusion with positron emission tomography].

    Science.gov (United States)

    vom Dahl, J

    2001-11-01

    Positron emission tomography (PET) of the heart has gained widespread scientific and clinical acceptance with regard to two indications: 1) The detection of perfusion abnormalities by qualitative and semiquantitative analyses of perfusion images at rest and during physical or pharmacological stress using well-validated perfusion tracers, such as N-13 ammonia, Rb-82 rubidium chloride, or O-15 labeled water. 2) Viability imaging of myocardial regions with reduced contractility by combining perfusion measurements with substrate metabolism as assessed from F-18 deoxyglucose utilization. This overview summarizes the use of PET as a perfusion imaging method. With a sensitivity > 90% in combination with high specificity, PET is today the best-validated available nuclear imaging technique for the diagnosis of coronary artery disease (CAD). The short half-life of the perfusion tracers in combination with highly sophisticated hard- and software enables rapid PET studies with high patient throughput. The high diagnostic accuracy and the methological advantages as compared to conventional scintigraphy allows one to use PET perfusion imaging to detect subtle changes in the perfusion reserve for the detection of CAD in high risk but asymptomatic patients as well as in patients with proven CAD undergoing various treatment forms such as risk factor reduction or coronary revascularization. In patients following orthotopic heart transplantation, evolving transplant vasculopathy can be detected at an early stage. Quantitative PET imaging at rest allows for detection of myocardial viability since cellular survival is based on maintenance of a minimal perfusion and structural changes correlate to the degree of perfusion reduction. Furthermore, quantitative assessment of the myocardial perfusion reserve detects the magnitude and competence of collaterals in regions with occluded epicardial collaterals and, thus, imaging of several coronary distribution territories in one noninvasive

  10. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo;

    2010-01-01

    radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  11. Cerebral perfusion SPECT in transient ischemic attack

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-04-01

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

  12. Brain Perfusion in Corticobasal Syndrome with Progressive Aphasia

    Directory of Open Access Journals (Sweden)

    Yoshitake Abe

    2016-04-01

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

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

    International Nuclear Information System (INIS)

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

  14. Development of a non-contrast-enhanced method for spatially resolved lung ventilation and perfusion measurement using Magnetic Resonance Imaging

    OpenAIRE

    Bauman, Grzegorz Leszek

    2010-01-01

    Assessment of the pulmonary function remains a challenge for the development of suitable MRI techniques due to the unique lung tissue structure and its short effective transverse relaxation time (T2* = 1 ms). In this work, a new method of non-contrast-enhanced lung ventilation and perfusion MRI is presented. A 2D bSSFP pulse sequence (TR/TE/TA = 1.9/0.8/116 ms, 3-7 images/s, FA = 75°, ST = 10 mm, matrix = 128 x 128, GRAPPA 3) was implemented on a 1.5 T MR-scanner. The method uses fast image a...

  15. Quantitative serial MRI of the treated fibroid uterus.

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    Kirsty I Munro

    Full Text Available There are no long-term medical treatments for uterine fibroids, and non-invasive biomarkers are needed to evaluate novel therapeutic interventions. The aim of this study was to determine whether serial dynamic contrast-enhanced MRI (DCE-MRI and magnetization transfer MRI (MT-MRI are able to detect changes that accompany volume reduction in patients administered GnRH analogue drugs, a treatment which is known to reduce fibroid volume and perfusion. Our secondary aim was to determine whether rapid suppression of ovarian activity by combining GnRH agonist and antagonist therapies results in faster volume reduction.Forty women were assessed for eligibility at gynaecology clinics in the region, of whom thirty premenopausal women scheduled for hysterectomy due to symptomatic fibroids were randomized to three groups, receiving (1 GnRH agonist (Goserelin, (2 GnRH agonist+GnRH antagonist (Goserelin and Cetrorelix or (3 no treatment. Patients were monitored by serial structural, DCE-MRI and MT-MRI, as well as by ultrasound and serum oestradiol concentration measurements from enrolment to hysterectomy (approximately 3 months.A volumetric treatment effect assessed by structural MRI occurred by day 14 of treatment (9% median reduction versus 9% increase in untreated women; P = 0.022 and persisted throughout. Reduced fibroid perfusion and permeability assessed by DCE-MRI occurred later and was demonstrable by 2-3 months (43% median reduction versus 20% increase respectively; P = 0.0093. There was no apparent treatment effect by MT-MRI. Effective suppression of oestradiol was associated with early volume reduction at days 14 (P = 0.041 and 28 (P = 0.0061.DCE-MRI is sensitive to the vascular changes thought to accompany successful GnRH analogue treatment of uterine fibroids and should be considered for use in future mechanism/efficacy studies of proposed fibroid drug therapies. GnRH antagonist administration does not appear to accelerate volume reduction

  16. MRI evaluation and safety in the developing brain.

    Science.gov (United States)

    Tocchio, Shannon; Kline-Fath, Beth; Kanal, Emanuel; Schmithorst, Vincent J; Panigrahy, Ashok

    2015-03-01

    Magnetic resonance imaging (MRI) evaluation of the developing brain has dramatically increased over the last decade. Faster acquisitions and the development of advanced MRI sequences, such as magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI), perfusion imaging, functional MR imaging (fMRI), and susceptibility-weighted imaging (SWI), as well as the use of higher magnetic field strengths has made MRI an invaluable tool for detailed evaluation of the developing brain. This article will provide an overview of the use and challenges associated with 1.5-T and 3-T static magnetic fields for evaluation of the developing brain. This review will also summarize the advantages, clinical challenges, and safety concerns specifically related to MRI in the fetus and newborn, including the implications of increased magnetic field strength, logistics related to transporting and monitoring of neonates during scanning, and sedation considerations, and a discussion of current technologies such as MRI conditional neonatal incubators and dedicated small-foot print neonatal intensive care unit (NICU) scanners. PMID:25743582

  17. 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)

  18. Pharmacoeconomic aspects related to the 13-valent pneumococcal conjugate vaccine: preliminary analysis of the data from the ASL of Viterbo

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    Dari Silvia

    2014-12-01

    Full Text Available INTRODUCTION: Streptococcus pneumoniae is a pathogen of considerable importance to public health because it causes morbidity and mortality on the world population. It has more than 90 serotypes with different epidemiological characteristics and pathogenicity. Some categories of the population are particularly vulnerable to infection. The Regional Plan for the Prevention of Lazio for vaccination, based on the national plan for the prevention for vaccination involves the active offer of vaccination no 13-valent PCV, with a target of at least 90% in children 24 months of age.OBJECTIVE: To begin to assess the real economic impact of disease attributable to Pneumococcus, starting from the analysis of hospital discharge records (SDO of the Viterbo's ASL.METHODS: The model is structured follows the observational approach of 33 months, from January 2012 to September 2014, selecting the SDO with a principal diagnosis of Streptococcus Pneumoniae diseases and those with a principal diagnosis of respiratory diseases without etiological diagnosis, which, with good approximation, it can be considered responsible for Streptococcus pneumoniae 40%.RESULTS: From the preliminary analysis of the data, evaluating only patients diagnosed due to Pneumococcus, is known as the only pediatric cases hospitalized are between 0 and 1 year. Therefore one might assume that vaccination disbursed to the child population with 13-valent PCV, has ensured effective protection to persons of the age group 2-18 years.CONCLUSIONS: The importance of this study is the observation conducted on an ASL, (similar in size and catchment area to many Italian realty of the vaccination coverage effects, as provided by PRPV Lazio Region, on hospitalizations by Pneumococcus. The study offers a moment of reflection for decision makers, as it would be interesting to conduct pharmacoeconomic’s analysis in the presence of vaccination strategies extended to adults, especially for those at risk

  19. A correlation of clinical, MRI and brain SPECT in dementia

    International Nuclear Information System (INIS)

    Background: Dementia is a clinical syndrome characterised by acquired impairment in multiple neuropsycologic and behavior domains including memory, language, speech, visuospatial ability, cognition and mood/personality. Dementia produces deficits in perfusion reflecting decreased metabolic needs. Neuroimaging techniques help in determining whether the cognitive symptoms are organic and in which pattern of cognitive loss the patient may evolve. AIM: To differentiate various types of Dementia, based on the regional perfusion abnormalities seen in Brain SPECT and correlate this with Clinical and MRI findings. Material and methods: Patients suffering from memory impairment and memory loss were referred to our department for Brain SPECT as a part of work up for Dementia. They had undergone a detailed clinical examination, psychometry, mini mental status examination (MMSE), memory/cognitive testing and an MRI. Brain SPECT was done after injecting Tc 99m ECD (Ethylene Cysteinate Dimer ) and imaging after 45 minutes. The images obtained were reconstructed in a conventional way. The various patterns of perfusion abnormalities seen in the SPECT images was studied and correlated with MRI and clinical findings. The patients were thus classified as having Multi Infarct Dementia, Alzheimer's disease, Fronto-Temporal Dementia and Mixed variety. Results: Twenty One Patients were included in our study from February 2003 to February 2004. The mean age of the patients was 73 years ( 37 to 81). 15 were males and 6 were females. Out of 21 patients, 12 had Multi Infarct Dementia, 4 had Alzheimer's disease, 1 had Fronto- Temporal Dementia and 4 had Mixed variety. Conclusion: Brain SPECT aids in substantiating the clinical findings and in correlation with MRI helps in distinguishing various types of Dementia and thus has prognostic implications and helps in instituting early appropriate treatment to the patient. In our study, the majority of the patients have Multi Infarct Dementia

  20. New literacies, multiple literacies, unlimited literacies: what now, what next, where to? A response to blue listerine, parochialism and ASL literacy.

    Science.gov (United States)

    Paul, Peter V

    2006-01-01

    This article is a response to Blue Listerine, Parochialism, and ASL Literacy (Czubek, 2006). The author presents his views on the concepts of literacy and the new and multiple literacies. In addition, the merits of print literacy and other types of literacies are discussed. Although the author agrees that there is an American Sign Language (ASL) literacy, he maintains that there should be a distinction between conversational "literacy" forms (speech and sign) and secondary literacy forms (reading and writing). It might be that cognitive skills associated with print literacy and, possibly, other captured literacy forms, are necessary for a technological, scientific-driven society such as that which exists in the United States.

  1. Blue laser emission by intracavity second harmonic generation in Nd:ASL pumped by a tapered amplifier laser diode stabilized by a volume Bragg grating

    OpenAIRE

    Pabœuf, David; Lucas-Leclin, Gaëlle; Georges, Patrick; Sumpf, Bernd; Ebert, Götz; Varona, Cyrille; Loiseau, Pascal; Aka, Gérard; Ferrand, Bernard

    2008-01-01

    International audience We present the diode pumping of a Nd:ASL (Sr1-xLax-yNdyMgxAl12-x O19) crystal for second harmonic generation at 453 nm. We have developed a high-brightness pump source based on a tapered amplifier in an extended cavity with a volume Bragg grating for wavelength stabilization. A pump brightness of 110 MW.cm-2sr-1 is obtained with a linewidth lower than 80 pm at 798 nm. This laser source is used to pump a Nd:ASL crystal to obtain 300 mW at 906 nm and 53 mW at 453 nm by...

  2. 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

  3. Respiratory tract exacerbations revisited: ventilation, inflammation, perfusion, and structure (VIPS) monitoring to redefine treatment.

    Science.gov (United States)

    Tiddens, Harm A W M; Stick, Stephen M; Wild, Jim M; Ciet, Pierluigi; Parker, Geoffrey J M; Koch, Armin; Vogel-Claussen, Jens

    2015-10-01

    For cystic fibrosis (CF) patients older than 6 years there are convincing data that suggest respiratory tract exacerbations (RTE) play an important role in the progressive loss of functional lung tissue. There is a poor understanding of the pathobiology of RTE and whether specific treatment of RTE reduces lung damage in the long term. In addition, there are limited tools available to measure the various components of CF lung disease and responses to therapy. Therefore, in order to better understand the impact of RTE on CF lung disease we need to develop sensitive measures to characterize RTE and responses to treatment; and improve our understanding of structure-function changes during treatment of RTE. In this paper we review our current knowledge of the impact of RTE on the progression of lung disease and identify strategies to improve our understanding of the pathobiology of RTE. By improving our knowledge regarding RTE in CF we will be better positioned to develop approaches to treatment that are individualized and that can prevent permanent structural damage. We suggest the development of a ventilation, perfusion, inflammation and structure (VIPS)-MRI suite that supplies the clinician with data on ventilation, inflammation, perfusion, and structure in one MRI session. VIPS-MRI could be an important step to better understand the factors that contribute to and limit treatment efficacy of RTE.

  4. 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.

  5. Toward microtesla MRI of hyperpolarized carbon-13 for real-time metabolic imaging

    CERN Document Server

    Zotev, V S; Savukov, I M; Matlashov, A N; Gómez, J J; Espy, M A

    2009-01-01

    Hyperpolarization of carbon-13 is a promising technique that has enabled MR angiography, perfusion mapping, and real-time metabolic imaging of C-13 labeled organic substances with unprecedented signal-to-noise levels. Because the hyperpolarization is performed outside an MRI scanner (using a special NMR-style hyperpolarizer), high magnetic fields of conventional MRI systems offer little advantage in terms of achievable C-13 polarization. Here we propose an ultimate low-field MRI scanner for imaging hyperpolarized C-13. It uses only microtesla-range magnetic fields and employs SQUID (superconducting quantum interference device) sensors for broadband reception of MRI signals. We present the first images acquired by SQUID-based microtesla MRI with dynamic nuclear polarization (Overhauser enhancement). We also report the first NMR spectra of C-13 at microtesla fields, including spectra of metabolically relevant sodium pyruvate, bicarbonate, and alanine. Our results demonstrate feasibility and potential of the pro...

  6. Multispectral optoacoustic and MRI coregistration for molecular imaging of orthotopic model of human glioblastoma.

    Science.gov (United States)

    Attia, Amalina Binte Ebrahim; Ho, Chris Jun Hui; Chandrasekharan, Prashant; Balasundaram, Ghayathri; Tay, Hui Chien; Burton, Neal C; Chuang, Kai-Hsiang; Ntziachristos, Vasilis; Olivo, Malini

    2016-07-01

    Multi-modality imaging methods are of great importance in oncologic studies for acquiring complementary information, enhancing the efficacy in tumor detection and characterization. We hereby demonstrate a hybrid non-invasive in vivo imaging approach of utilizing magnetic resonance imaging (MRI) and Multispectral Optoacoustic Tomography (MSOT) for molecular imaging of glucose uptake in an orthotopic glioblastoma in mouse. The molecular and functional information from MSOT can be overlaid on MRI anatomy via image coregistration to provide insights into probe uptake in the brain, which is verified by ex vivo fluorescence imaging and histological validation. In vivo MSOT and MRI imaging of an orthotopic glioma mouse model injected with IRDye800-2DG. Image coregistration between MSOT and MRI enables multifaceted (anatomical, functional, molecular) information from MSOT to be overlaid on MRI anatomy images to derive tumor physiological parameters such as perfusion, haemoglobin and oxygenation. PMID:27091626

  7. Cochlear perfusion with a viscous fluid.

    Science.gov (United States)

    Wang, Yi; Olson, Elizabeth S

    2016-07-01

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

  8. 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

  9. Is the cerebellum the optimal reference region for intensity normalization of perfusion MR studies in early Alzheimer's disease?

    Directory of Open Access Journals (Sweden)

    María Lacalle-Aurioles

    Full Text Available The cerebellum is the region most commonly used as a reference when normalizing the intensity of perfusion images acquired using magnetic resonance imaging (MRI in Alzheimer's disease (AD studies. In addition, the cerebellum provides unbiased estimations with nuclear medicine techniques. However, no reports confirm the cerebellum as an optimal reference region in MRI studies or evaluate the consequences of using different normalization regions. In this study, we address the effect of using the cerebellum, whole-brain white matter, and whole-brain cortical gray matter in the normalization of cerebral blood flow (CBF parametric maps by comparing patients with stable mild cognitive impairment (MCI, patients with AD and healthy controls. According to our results, normalization by whole-brain cortical gray matter enables more sensitive detection of perfusion abnormalities in AD patients and reveals a larger number of affected regions than data normalized by the cerebellum or whole-brain white matter. Therefore, the cerebellum is not the most valid reference region in MRI studies for early stages of AD. After normalization by whole-brain cortical gray matter, we found a significant decrease in CBF in both parietal lobes and an increase in CBF in the right medial temporal lobe. We found no differences in perfusion between patients with stable MCI and healthy controls either before or after normalization.

  10. Is the Cerebellum the Optimal Reference Region for Intensity Normalization of Perfusion MR Studies in Early Alzheimer’s Disease?

    Science.gov (United States)

    Lacalle-Aurioles, María; Alemán-Gómez, Yasser; Guzmán-De-Villoria, Juan Adán; Cruz-Orduña, Isabel; Olazarán, Javier; Mateos-Pérez, José María; Martino, María Elena; Desco, Manuel

    2013-01-01

    The cerebellum is the region most commonly used as a reference when normalizing the intensity of perfusion images acquired using magnetic resonance imaging (MRI) in Alzheimer’s disease (AD) studies. In addition, the cerebellum provides unbiased estimations with nuclear medicine techniques. However, no reports confirm the cerebellum as an optimal reference region in MRI studies or evaluate the consequences of using different normalization regions. In this study, we address the effect of using the cerebellum, whole-brain white matter, and whole-brain cortical gray matter in the normalization of cerebral blood flow (CBF) parametric maps by comparing patients with stable mild cognitive impairment (MCI), patients with AD and healthy controls. According to our results, normalization by whole-brain cortical gray matter enables more sensitive detection of perfusion abnormalities in AD patients and reveals a larger number of affected regions than data normalized by the cerebellum or whole-brain white matter. Therefore, the cerebellum is not the most valid reference region in MRI studies for early stages of AD. After normalization by whole-brain cortical gray matter, we found a significant decrease in CBF in both parietal lobes and an increase in CBF in the right medial temporal lobe. We found no differences in perfusion between patients with stable MCI and healthy controls either before or after normalization. PMID:24386081

  11. Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas—Initial study

    Energy Technology Data Exchange (ETDEWEB)

    Slapa, Rafal Z., E-mail: rz.slapa@gmail.com [Diagnostic Imaging Department, Medical University of Warsaw, Second Faculty of Medicine with English and Physiotherapy Divisions, Warsaw (Poland); Kasperlik–Zaluska, Anna A. [Endocrinology Department, Center for Postgraduate Medical Education, Bielanski Hospital, Warsaw (Poland); Migda, Bartosz [Diagnostic Imaging Department, Medical University of Warsaw, Second Faculty of Medicine with English and Physiotherapy Divisions, Warsaw (Poland); Otto, Maciej [Department of General, Vascular and Transplant Surgery, Medical University of Warsaw, First Faculty of Medicine, Warsaw (Poland); Jakubowski, Wiesław S. [Diagnostic Imaging Department, Medical University of Warsaw, Second Faculty of Medicine with English and Physiotherapy Divisions, Warsaw (Poland)

    2015-08-15

    Highlights: • Adrenal masses may differ on parametric perfusion ultrasound. • Hyperplastic nodules present distinctive patterns on CEUS in regard to adenomas. • Adrenal lesions perfusion should be further investigated with different modalities. - Abstract: Objectives: To evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging. Patients and Methods: 34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination. Results: The study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas. Conclusions: Parametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients.

  12. Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas—Initial study

    International Nuclear Information System (INIS)

    Highlights: • Adrenal masses may differ on parametric perfusion ultrasound. • Hyperplastic nodules present distinctive patterns on CEUS in regard to adenomas. • Adrenal lesions perfusion should be further investigated with different modalities. - Abstract: Objectives: To evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging. Patients and Methods: 34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination. Results: The study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas. Conclusions: Parametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients

  13. MRI in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Mulert, Christoph [UKE, Hamburg (Germany). Psychiatry Neuroimaging Branch; Shenton, Martha E. (ed.) [Harvard Medical School, Boston, MA (United States). Dept. of Psychiatry and Radiology

    2014-07-01

    This is the first comprehensive textbook on the use of MRI in psychiatry covering imaging techniques, brain systems and a review of findings in different psychiatric disorders. The book is divided into three sections, the first of which covers in detail all the major MRI-based methodological approaches available today, including fMRI, EEG-fMRI, DTI, and MR spectroscopy. In addition, the role of MRI in imaging genetics and combined brain stimulation and imaging is carefully explained. The second section provides an overview of the different brain systems that are relevant for psychiatric disorders, including the systems for perception, emotion, cognition, and reward. The final part of the book presents the MRI findings that are obtained in all the major psychiatric disorders using the previously discussed techniques. Numerous carefully chosen images support the informative text, making this an ideal reference work for all practitioners and trainees with an interest in this flourishing field.

  14. 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.