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Sample records for quantitative perfusion imaging

  1. Quantitative and qualitative analysis and interpretation of CT perfusion imaging.

    Science.gov (United States)

    Valdiviezo, Carolina; Ambrose, Marietta; Mehra, Vishal; Lardo, Albert C; Lima, Joao A C; George, Richard T

    2010-12-01

    Coronary artery disease (CAD) remains the leading cause of death in the United States. Rest and stress myocardial perfusion imaging has an important role in the non-invasive risk stratification of patients with CAD. However, diagnostic accuracies have been limited, which has led to the development of several myocardial perfusion imaging techniques. Among them, myocardial computed tomography perfusion imaging (CTP) is especially interesting as it has the unique capability of providing anatomic- as well as coronary stenosis-related functional data when combined with computed tomography angiography (CTA). The primary aim of this article is to review the qualitative, semi-quantitative, and quantitative analysis approaches to CTP imaging. In doing so, we will describe the image data required for each analysis and discuss the advantages and disadvantages of each approach.

  2. 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.

  3. 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

  4. Quantitative perfusion imaging in magnetic resonance imaging; Quantitative Perfusionsbildgebung in der Magnetresonanztomographie

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    Zoellner, F.G.; Gaa, T.; Zimmer, F. [Universitaet Heidelberg, Computerunterstuetzte Klinische Medizin, Medizinische Fakultaet Mannheim, Mannheim (Germany); Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M. [Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim, Mannheim (Germany)

    2016-02-15

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [German] Die Magnetresonanztomographie (MRT) zeichnet sich durch einen ueberlegenen Gewebekontrast aus, waehrend sie nichtinvasiv und frei von ionisierender Strahlung ist. Sie bietet Zugang zu Gewebe- und Organfunktion. Eine dieser funktionellen bildgebenden Verfahren ist die Perfusionsbildgebung. Mit dieser Technik koennen u. a. Gewebeperfusion und Kapillarpermeabilitaet aus dynamischen Bilddaten bestimmt werden. Perfusionsbildgebung mithilfe der MRT kann durch 2 Ansaetze, naemlich ''arterial spin labeling'' (ASL) und dynamische kontrastverstaerkte (DCE-)MRT durchgefuehrt werden. Waehrend die erste Methode magnetisch

  5. Dependence of quantitative accuracy of CT perfusion imaging on system parameters

    Science.gov (United States)

    Li, Ke; Chen, Guang-Hong

    2017-03-01

    Deconvolution is a popular method to calculate parametric perfusion parameters from four dimensional CT perfusion (CTP) source images. During the deconvolution process, the four dimensional space is squeezed into three-dimensional space by removing the temporal dimension, and a prior knowledge is often used to suppress noise associated with the process. These additional complexities confound the understanding about deconvolution-based CTP imaging system and how its quantitative accuracy depends on parameters and sub-operations involved in the image formation process. Meanwhile, there has been a strong clinical need in answering this question, as physicians often rely heavily on the quantitative values of perfusion parameters to make diagnostic decisions, particularly during an emergent clinical situation (e.g. diagnosis of acute ischemic stroke). The purpose of this work was to develop a theoretical framework that quantitatively relates the quantification accuracy of parametric perfusion parameters with CTP acquisition and post-processing parameters. This goal was achieved with the help of a cascaded systems analysis for deconvolution-based CTP imaging systems. Based on the cascaded systems analysis, the quantitative relationship between regularization strength, source image noise, arterial input function, and the quantification accuracy of perfusion parameters was established. The theory could potentially be used to guide developments of CTP imaging technology for better quantification accuracy and lower radiation dose.

  6. Quantitation of Brown Adipose Tissue Perfusion in Transgenic Mice Using Near-Infrared Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Akira Nakayama

    2003-01-01

    Full Text Available Brown adipose tissue (BAT; brown fat is the principal site of adaptive thermogenesis in the human newborn and other small mammals. Of paramount importance for thermogenesis is vascular perfusion, which controls the flow of cool blood in, and warmed blood out, of BAT. We have developed an optical method for the quantitative imaging of BAT perfusion in the living, intact animal using the heptamethine indocyanine IR-786 and near-infrared (NIR fluorescent light. We present a detailed analysis of the physical, chemical, and cellular properties of IR-786, its biodistribution and pharmacokinetics, and its uptake into BAT. Using transgenic animals with homozygous deletion of Type II iodothyronine deiodinase, or homozygous deletion of uncoupling proteins (UCPs 1 and 2, we demonstrate that BAT perfusion can be measured noninvasively, accurately, and reproducibly. Using these techniques, we show that UCP 1/2 knockout animals, when compared to wild-type animals, have a higher baseline perfusion of BAT but a similar maximal response to β3-receptor agonist. These results suggest that compensation for UCP deletion is mediated, in part, by the control of BAT perfusion. Taken together, BAT perfusion can now be measured noninvasively using NIR fluorescent light, and pharmacological modulators of thermogenesis can be screened at relatively high throughput in living animals.

  7. Quantitative assessment of brain perfusion with magnetic resonance imaging

    NARCIS (Netherlands)

    Bleeker, Egbert Jan Willem

    2011-01-01

    This thesis focuses on assessing blood supply to brain tissue using MRI. For Dynamic Susceptibility Contrast-MRI a series of images is acquired during the passage of a bolus contrast agent through the brain up to the point that the contrast agent is equally mixed within the total blood pool. The tis

  8. Image registration and analysis for quantitative myocardial perfusion: application to dynamic circular cardiac CT

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    Isola, A A [Philips Research Laboratories, X-ray Imaging Systems Department, Weisshausstrasse 2, D-52066 Aachen (Germany); Schmitt, H; Van Stevendaal, U; Grass, M [Philips Research Laboratories, Sector Digital Imaging, Roentgenstrasse 24-26, D-22335 Hamburg (Germany); Begemann, P G [Department of Radiology, University Hospital Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg (Germany); Coulon, P [Philips Healthcare France, 33 rue de Verdun, F-92150 Suresnes Cedex (France); Boussel, L, E-mail: Alfonso.Isola@Philips.com [Department of Radiology, Louis Pradel Hospital, CREATIS, UMR CNRS 5515, INSERM U630, Lyon (France)

    2011-09-21

    Large area detector computed tomography systems with fast rotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively, ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce x-ray dose and limit motion artefacts. Even in the case of highly accurate prospective triggering and stable heart rate, spatial misalignment of the cardiac volumes acquired and reconstructed per cardiac cycle may occur due to small motion pattern variations from cycle to cycle. These misalignments reduce the accuracy of the quantitative analysis of myocardial perfusion parameters on a per voxel basis. An image-based solution to this problem is elastic 3D image registration of dynamic volume sequences with variable contrast, as it is introduced in this contribution. After circular cone-beam CT reconstruction of cardiac volumes covering large areas of the myocardial tissue, the complete series is aligned with respect to a chosen reference volume. The results of the registration process and the perfusion analysis with and without registration are evaluated quantitatively in this paper. The spatial alignment leads to improved quantification of myocardial perfusion for three different pig data sets.

  9. Image registration and analysis for quantitative myocardial perfusion: application to dynamic circular cardiac CT

    Science.gov (United States)

    Isola, A. A.; Schmitt, H.; van Stevendaal, U.; Begemann, P. G.; Coulon, P.; Boussel, L.; Grass, M.

    2011-09-01

    Large area detector computed tomography systems with fast rotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively, ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce x-ray dose and limit motion artefacts. Even in the case of highly accurate prospective triggering and stable heart rate, spatial misalignment of the cardiac volumes acquired and reconstructed per cardiac cycle may occur due to small motion pattern variations from cycle to cycle. These misalignments reduce the accuracy of the quantitative analysis of myocardial perfusion parameters on a per voxel basis. An image-based solution to this problem is elastic 3D image registration of dynamic volume sequences with variable contrast, as it is introduced in this contribution. After circular cone-beam CT reconstruction of cardiac volumes covering large areas of the myocardial tissue, the complete series is aligned with respect to a chosen reference volume. The results of the registration process and the perfusion analysis with and without registration are evaluated quantitatively in this paper. The spatial alignment leads to improved quantification of myocardial perfusion for three different pig data sets.

  10. Quantitative myocardial perfusion PET parametric imaging at the voxel-level.

    Science.gov (United States)

    Mohy-Ud-Din, Hassan; Lodge, Martin A; Rahmim, Arman

    2015-08-01

    Quantitative myocardial perfusion (MP) PET has the potential to enhance detection of early stages of atherosclerosis or microvascular dysfunction, characterization of flow-limiting effects of coronary artery disease (CAD), and identification of balanced reduction of flow due to multivessel stenosis. We aim to enable quantitative MP-PET at the individual voxel level, which has the potential to allow enhanced visualization and quantification of myocardial blood flow (MBF) and flow reserve (MFR) as computed from uptake parametric images. This framework is especially challenging for the (82)Rb radiotracer. The short half-life enables fast serial imaging and high patient throughput; yet, the acquired dynamic PET images suffer from high noise-levels introducing large variability in uptake parametric images and, therefore, in the estimates of MBF and MFR. Robust estimation requires substantial post-smoothing of noisy data, degrading valuable functional information of physiological and pathological importance. We present a feasible and robust approach to generate parametric images at the voxel-level that substantially reduces noise without significant loss of spatial resolution. The proposed methodology, denoted physiological clustering, makes use of the functional similarity of voxels to penalize deviation of voxel kinetics from physiological partners. The results were validated using extensive simulations (with transmural and non-transmural perfusion defects) and clinical studies. Compared to post-smoothing, physiological clustering depicted enhanced quantitative noise versus bias performance as well as superior recovery of perfusion defects (as quantified by CNR) with minimal increase in bias. Overall, parametric images obtained from the proposed methodology were robust in the presence of high-noise levels as manifested in the voxel time-activity-curves.

  11. Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system

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    Fahmi, Rachid; Eck, Brendan L.; Levi, Jacob; Fares, Anas; Dhanantwari, Amar; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR  <  0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29  ±  0.01, over-estimating stenosis severity as compared to 0.42  ±  0.01 (p  <  0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50  ±  0.04 falsely indicating an actionable ischemic condition in a healthy

  12. Vibration-response imaging versus quantitative perfusion scintigraphy in the selection of patients for lung-resection surgery.

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    Comce, Fatma; Bingol, Zuleyha; Kiyan, Esen; Tanju, Serhan; Toker, Alper; Cagatay, Pembe; Ece, Turhan

    2011-12-01

    In patients being considered for lung-resection surgery, quantitative perfusion scintigraphy is used to predict postoperative lung function and guide the determination of lung-resection candidacy. Vibration-response imaging has been proposed as a noninvasive, radiation-free, and simpler method to predict postoperative lung function. We compared vibration-response imaging to quantitative perfusion scintigraphy for predicting postoperative FEV(1) and diffusing capacity of the lung for carbon monoxide (D(LCO)). We enrolled 35 candidates for lung resection. Twenty-five patients had preoperative FEV(1) and D(LCO) MEASUREMENTS: The vibration-response-imaging measurements showed strong correlation with the quantitative-perfusion-scintigraphy measurements of predicted postoperative FEV(1)% (r = 0.87, P scintigraphy and the actual postoperative FEV(1) (% and L) (r = 0.47, P = .048, r = 0.73, P scintigraphy. Neither the vibration-response imaging nor the quantitative perfusion scintigraphy predicted postoperative D(LCO)% values agreed with the actual postoperative D(LCO)% values. Vibration-response imaging may be a good alternative to quantitative perfusion scintigraphy in evaluating lung-resection candidacy.

  13. Effects of acquisition time and reconstruction algorithm on image quality, quantitative parameters, and clinical interpretation of myocardial perfusion imaging

    DEFF Research Database (Denmark)

    Enevoldsen, Lotte H; Menashi, Changez A K; Andersen, Ulrik B;

    2013-01-01

    BACKGROUND: Recently introduced iterative reconstruction algorithms with resolution recovery (RR) and noise-reduction technology seem promising for reducing scan time or radiation dose without loss of image quality. However, the relative effects of reduced acquisition time and reconstruction...... software have not previously been reported. The aim of the present study was to investigate the influence of reduced acquisition time and reconstruction software on quantitative and qualitative myocardial perfusion single photon emission computed tomography (SPECT) parameters using full time (FT) and half...... time (HT) protocols and Evolution for Cardiac Software. METHODS: We studied 45 consecutive, non-selected patients referred for a clinically indicated routine 2-day stress/rest (99m)Tc-Sestamibi myocardial perfusion SPECT. All patients underwent an FT and an HT scan. Both FT and HT scans were processed...

  14. Simulation of realistic abnormal SPECT brain perfusion images: application in semi-quantitative analysis

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    Ward, T [Department of Medical Physics and Bioengineering, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom); Fleming, J S [Department of Medical Physics and Bioengineering, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom); Hoffmann, S M A [Department of Medical Physics and Bioengineering, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom); Kemp, P M [Department of Nuclear Medicine, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom)

    2005-11-21

    Simulation is useful in the validation of functional image analysis methods, particularly when considering the number of analysis techniques currently available lacking thorough validation. Problems exist with current simulation methods due to long run times or unrealistic results making it problematic to generate complete datasets. A method is presented for simulating known abnormalities within normal brain SPECT images using a measured point spread function (PSF), and incorporating a stereotactic atlas of the brain for anatomical positioning. This allows for the simulation of realistic images through the use of prior information regarding disease progression. SPECT images of cerebral perfusion have been generated consisting of a control database and a group of simulated abnormal subjects that are to be used in a UK audit of analysis methods. The abnormality is defined in the stereotactic space, then transformed to the individual subject space, convolved with a measured PSF and removed from the normal subject image. The dataset was analysed using SPM99 (Wellcome Department of Imaging Neuroscience, University College, London) and the MarsBaR volume of interest (VOI) analysis toolbox. The results were evaluated by comparison with the known ground truth. The analysis showed improvement when using a smoothing kernel equal to system resolution over the slightly larger kernel used routinely. Significant correlation was found between effective volume of a simulated abnormality and the detected size using SPM99. Improvements in VOI analysis sensitivity were found when using the region median over the region mean. The method and dataset provide an efficient methodology for use in the comparison and cross validation of semi-quantitative analysis methods in brain SPECT, and allow the optimization of analysis parameters.

  15. Simulation of realistic abnormal SPECT brain perfusion images: application in semi-quantitative analysis

    Science.gov (United States)

    Ward, T.; Fleming, J. S.; Hoffmann, S. M. A.; Kemp, P. M.

    2005-11-01

    Simulation is useful in the validation of functional image analysis methods, particularly when considering the number of analysis techniques currently available lacking thorough validation. Problems exist with current simulation methods due to long run times or unrealistic results making it problematic to generate complete datasets. A method is presented for simulating known abnormalities within normal brain SPECT images using a measured point spread function (PSF), and incorporating a stereotactic atlas of the brain for anatomical positioning. This allows for the simulation of realistic images through the use of prior information regarding disease progression. SPECT images of cerebral perfusion have been generated consisting of a control database and a group of simulated abnormal subjects that are to be used in a UK audit of analysis methods. The abnormality is defined in the stereotactic space, then transformed to the individual subject space, convolved with a measured PSF and removed from the normal subject image. The dataset was analysed using SPM99 (Wellcome Department of Imaging Neuroscience, University College, London) and the MarsBaR volume of interest (VOI) analysis toolbox. The results were evaluated by comparison with the known ground truth. The analysis showed improvement when using a smoothing kernel equal to system resolution over the slightly larger kernel used routinely. Significant correlation was found between effective volume of a simulated abnormality and the detected size using SPM99. Improvements in VOI analysis sensitivity were found when using the region median over the region mean. The method and dataset provide an efficient methodology for use in the comparison and cross validation of semi-quantitative analysis methods in brain SPECT, and allow the optimization of analysis parameters.

  16. Comparison of Myocardial Perfusion Estimates From Dynamic Contrast-Enhanced Magnetic Resonance Imaging With Four Quantitative Analysis Methods

    Science.gov (United States)

    Pack, Nathan A.; DiBella, Edward V. R.

    2012-01-01

    Dynamic contrast-enhanced MRI has been used to quantify myocardial perfusion in recent years. Published results have varied widely, possibly depending on the method used to analyze the dynamic perfusion data. Here, four quantitative analysis methods (two-compartment modeling, Fermi function modeling, model-independent analysis, and Patlak plot analysis) were implemented and compared for quantifying myocardial perfusion. Dynamic contrast-enhanced MRI data were acquired in 20 human subjects at rest with low-dose (0.019 ± 0.005 mmol/kg) bolus injections of gadolinium. Fourteen of these subjects were also imaged at adenosine stress (0.021 ± 0.005 mmol/kg). Aggregate rest perfusion estimates were not significantly different between all four analysis methods. At stress, perfusion estimates were not significantly different between two-compartment modeling, model-independent analysis, and Patlak plot analysis. Stress estimates from the Fermi model were significantly higher (~20%) than the other three methods. Myocardial perfusion reserve values were not significantly different between all four methods. Model-independent analysis resulted in the lowest model curve-fit errors. When more than just the first pass of data was analyzed, perfusion estimates from two-compartment modeling and model-independent analysis did not change significantly, unlike results from Fermi function modeling. PMID:20577976

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

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  19. Magnetic resonance perfusion imaging without contrast media

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    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.)

  20. Comparison of quantitative myocardial perfusion imaging CT to fluorescent microsphere-based flow from high-resolution cryo-images

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    Eck, Brendan L.; Fahmi, Rachid; Levi, Jacob; Fares, Anas; Wu, Hao; Li, Yuemeng; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    Myocardial perfusion imaging using CT (MPI-CT) has the potential to provide quantitative measures of myocardial blood flow (MBF) which can aid the diagnosis of coronary artery disease. We evaluated the quantitative accuracy of MPI-CT in a porcine model of balloon-induced LAD coronary artery ischemia guided by fractional flow reserve (FFR). We quantified MBF at baseline (FFR=1.0) and under moderate ischemia (FFR=0.7) using MPI-CT and compared to fluorescent microsphere-based MBF from high-resolution cryo-images. Dynamic, contrast-enhanced CT images were obtained using a spectral detector CT (Philips Healthcare). Projection-based mono-energetic images were reconstructed and processed to obtain MBF. Three MBF quantification approaches were evaluated: singular value decomposition (SVD) with fixed Tikhonov regularization (ThSVD), SVD with regularization determined by the L-Curve criterion (LSVD), and Johnson-Wilson parameter estimation (JW). The three approaches over-estimated MBF compared to cryo-images. JW produced the most accurate MBF, with average error 33.3+/-19.2mL/min/100g, whereas LSVD and ThSVD had greater over-estimation, 59.5+/-28.3mL/min/100g and 78.3+/-25.6 mL/min/100g, respectively. Relative blood flow as assessed by a flow ratio of LAD-to-remote myocardium was strongly correlated between JW and cryo-imaging, with R2=0.97, compared to R2=0.88 and 0.78 for LSVD and ThSVD, respectively. We assessed tissue impulse response functions (IRFs) from each approach for sources of error. While JW was constrained to physiologic solutions, both LSVD and ThSVD produced IRFs with non-physiologic properties due to noise. The L-curve provided noise-adaptive regularization but did not eliminate non-physiologic IRF properties or optimize for MBF accuracy. These findings suggest that model-based MPI-CT approaches may be more appropriate for quantitative MBF estimation and that cryo-imaging can support the development of MPI-CT by providing spatial distributions of MBF.

  1. 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.

  2. Impact of image denoising on image quality, quantitative parameters and sensitivity of ultra-low-dose volume perfusion CT imaging

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    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikoubashman, Omid; Brockmann, Marc A.; Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Yang, Zepa; Kim, Changwon [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Nikolaou, Konstantin [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Kim, Jong Hyo [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Advanced Institute of Convergence Technology, Center for Medical-IT Convergence Technology Research, Suwon (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of)

    2016-01-15

    To examine the impact of denoising on ultra-low-dose volume perfusion CT (ULD-VPCT) imaging in acute stroke. Simulated ULD-VPCT data sets at 20 % dose rate were generated from perfusion data sets of 20 patients with suspected ischemic stroke acquired at 80 kVp/180 mAs. Four data sets were generated from each ULD-VPCT data set: not-denoised (ND); denoised using spatiotemporal filter (D1); denoised using quanta-stream diffusion technique (D2); combination of both methods (D1 + D2). Signal-to-noise ratio (SNR) was measured in the resulting 100 data sets. Image quality, presence/absence of ischemic lesions, CBV and CBF scores according to a modified ASPECTS score were assessed by two blinded readers. SNR and qualitative scores were highest for D1 + D2 and lowest for ND (all p ≤ 0.001). In 25 % of the patients, ND maps were not assessable and therefore excluded from further analyses. Compared to original data sets, in D2 and D1 + D2, readers correctly identified all patients with ischemic lesions (sensitivity 1.0, kappa 1.0). Lesion size was most accurately estimated for D1 + D2 with a sensitivity of 1.0 (CBV) and 0.94 (CBF) and an inter-rater agreement of 1.0 and 0.92, respectively. An appropriate combination of denoising techniques applied in ULD-VPCT produces diagnostically sufficient perfusion maps at substantially reduced dose rates as low as 20 % of the normal scan. (orig.)

  3. Quantitative myocardial perfusion magnetic resonance imaging: the impact of pulsatile flow on contrast agent bolus dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Graafen, Dirk; Hamer, Julia; Weber, Stefan; Schreiber, Laura M, E-mail: graafen@uni-mainz.de [Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz (Germany)

    2011-08-21

    Myocardial blood flow (MBF) can be quantified using T{sub 1}-weighted first-pass magnetic resonance imaging (MRI) in combination with a tracer-kinetic model, like MMID4. This procedure requires the knowledge of an arterial input function which is usually estimated from the left ventricle (LV). Dispersion of the contrast agent bolus may occur between the LV and the tissue of interest. The aim of this study was to investigate the dispersion under conditions of physiological pulsatile blood flow, and to simulate its effect on MBF quantification. The dispersion was simulated in coronary arteries using a computational fluid dynamics (CFD) approach. Simulations were accomplished on straight vessels with stenosis of different degrees and shapes. The results show that dispersion is more pronounced under resting conditions than during hyperemia. Stenosis leads to a reduction of dispersion. In consequence, dispersion results in a systematic MBF underestimation between -0.4% and -9.3%. The relative MBF error depends not only on the dispersion but also on the actual MBF itself. Since MBF under rest is more underestimated than under stress, myocardial perfusion reserve is overestimated between 0.1% and 4.5%. Considering other sources of errors in myocardial perfusion MRI, systematic errors of MBF by bolus dispersion are relatively small.

  4. Quantitative evaluation of benign meningioma and hemangiopericytoma with peritumoral brain edema by 64-slice CT perfusion imaging

    Institute of Scientific and Technical Information of China (English)

    REN Guang; CHEN Shuang; WANG Yin; ZHU Rui-jiang; GENG Dao-ying; FENG Xiao-yuan

    2010-01-01

    Background Hemangiopericytomas (HPCs) have a relentless tendency for local recurrence and metastases,differentiating between benign meningiomas and HPCs before surgery is important for both treatment planning and the prognosis appraisal.The purpose of this study was to evaluate the correlations between CT perfusion parameters and microvessel density (MVD) in extra-axial tumors and the possible role of CT perfusion imaging in preoperatively differentiating benign meningiomas and HPCs.Methods Seventeen patients with benign meningiomas and peritumoral edema, 12 patients with HPCs and peritumoral edema underwent 64-slice CT perfusion imaging pre-operation.Perfusion was calculated using the Patlak method.The quantitative parameters, include cerebral blood volume (CBV), permeability surface (PS) of parenchyma, peritumoral edema among benign meningiomas and HPCs were compared respectively.CBV and PS in parenchyma, peritumoral edema of benign meningiomas and HPCs were also compared to that of the contrallateral normal white matter respectively.The correlations between CBV, PS of tumoral parenchyma and MVD were examined.Results The value of CBV and PS in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05), while the values of CBV and PS in peritumoral edema of benign meningiomas and HPCs were not significantly different (P >0.05).MVD in parenchyma of HPCs were significantly higher than that of benign meningiomas (P<0.05).There were positive correlations between CBV and MVD (r=0.648, P<0.05), PS and MVD (r=0.541, P<0.05) respectively.Furthermore, the value of CBV and PS in parenchyma of benign meningiomas and HPCs were significantly higher than that of contrallateral normal white matter (P<0.05), the value of CBV in peritumoral edema of benign meningiomas and HPCs were significantly lower than that of contrallateral normal white matter (P<0.05), while the value of PS in peritumoral edema of benign meningiomas and HPCs were not

  5. FLASH proton density imaging for improved surface coil intensity correction in quantitative and semi-quantitative SSFP perfusion cardiovascular magnetic resonance.

    Science.gov (United States)

    Nielles-Vallespin, Sonia; Kellman, Peter; Hsu, Li-Yueh; Arai, Andrew E

    2015-02-17

    A low excitation flip angle (α coil intensity correction (SCIC) of the saturation-recovery (SR) prepared high flip angle (α = 40-50°) SSFP myocardial perfusion images. The different SSFP off-resonance response for these two flip angles might lead to suboptimal SCIC when there is a spatial variation in the background B0-field. The low flip angle SSFP-PD frames are more prone to parallel imaging banding artifacts in the presence of off-resonance. The use of FLASH-PD frames would eliminate both the banding artifacts and the uneven frequency response in the presence of off-resonance in the surface coil inhomogeneity estimate and improve homogeneity of semi-quantitative and quantitative perfusion measurements. B0-field maps, SSFP and FLASH-PD frames were acquired in 10 healthy volunteers to analyze the SSFP off-resonance response. Furthermore, perfusion scans preceded by both FLASH and SSFP-PD frames from 10 patients with no myocardial infarction were analyzed semi-quantitatively and quantitatively (rest n = 10 and stress n = 1). Intra-subject myocardial blood flow (MBF) coefficient of variation (CoV) over the whole left ventricle (LV), as well as intra-subject peak contrast (CE) and upslope (SLP) standard deviation (SD) over 6 LV sectors were investigated. In the 6 out of 10 cases where artifacts were apparent in the LV ROI of the SSFP-PD images, all three variability metrics were statistically significantly lower when using the FLASH-PD frames as input for the SCIC (CoVMBF-FLASH = 0.3 ± 0.1, CoVMBF-SSFP = 0.4 ± 0.1, p = 0.03; SDCE-FLASH = 10 ± 2, SDCE-SSFP = 32 ± 7, p = 0.01; SDSLP-FLASH = 0.02 ± 0.01, SDSLP-SSFP = 0.06 ± 0.02, p = 0.03). Example rest and stress data sets from the patient pool demonstrate that the low flip angle SSFP protocol can exhibit severe ghosting artifacts originating from off-resonance banding artifacts at the edges of the field of view that parallel imaging is

  6. 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.

    2014-01-01

    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 that 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 seconds. In this initial implementation, a FAIR (Flow-Sensitive Alternating Inversion Recovery) 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 T and 9.4 T (249±38 ml/min/100g and 241±17 ml/min/100g, respectively). The utility of this method was further demonstrated in detecting 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. PMID:24891124

  7. 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. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Feasibility of quantitative lung perfusion by 4D CT imaging by a new dynamic-scanning protocol in an animal model

    Science.gov (United States)

    Wang, Yang; Goldin, Jonathan G.; Abtin, Fereidoun G.; Brown, Matt; McNitt-Gray, Mike

    2008-03-01

    The purpose of this study is to test a new dynamic Perfusion-CT imaging protocol in an animal model and investigate the feasibility of quantifying perfusion of lung parenchyma to perform functional analysis from 4D CT image data. A novel perfusion-CT protocol was designed with 25 scanning time points: the first at baseline and 24 scans after a bolus injection of contrast material. Post-contrast CT scanning images were acquired with a high sampling rate before the first blood recirculation and then a relatively low sampling rate until 10 minutes after administrating contrast agent. Lower radiation techniques were used to keep the radiation dose to an acceptable level. 2 Yorkshire swine with pulmonary emboli underwent this perfusion- CT protocol at suspended end inspiration. The software tools were designed to measure the quantitative perfusion parameters (perfusion, permeability, relative blood volume, blood flow, wash-in & wash-out enhancement) of voxel or interesting area of lung. The perfusion values were calculated for further lung functional analysis and presented visually as contrast enhancement maps for the volume being examined. The results show increased CT temporal sampling rate provides the feasibility of quantifying lung function and evaluating the pulmonary emboli. Differences between areas with known perfusion defects and those without perfusion defects were observed. In conclusion, the techniques to calculate the lung perfusion on animal model have potential application in human lung functional analysis such as evaluation of functional effects of pulmonary embolism. With further study, these techniques might be applicable in human lung parenchyma characterization and possibly for lung nodule characterization.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

  10. Quantitative perfusion parameters in a cohort of patients with no known ischemic heart disease and normal myocardial perfusion imaging studied by 82Rb-PET

    DEFF Research Database (Denmark)

    Hoff, Camilla; Balche, Abdallah; Majgaard, J

    Purpose 82Rb perfusion PET allows for visual as well as quantitative interpretation of myocardial function. Whereas visual interpretation relies on intra-individual redistribution of the tracer between rest and stress studies, quantitative interpretation of absolute flow values requires robust......-month period were screened for eligibility. One hundred and eighty patients with no prior history of ischemic heart disease, a normal MPI scan defined by visual interpretation and no coronary events for a follow-up period of 6 months were included as normal. Quantitative parameters were calculated using...... commercially available software (QPET, Cedars Sinai). Parameters included were regional and global rest and stress myocardial blood flow (MBF) values, ejection fraction (EF) and total perfusion deficit (TPD). Results Mean global MBF at stress was 2.92 mL/g/min (±SD 0.49), lower limit (LL) 1.94 m...

  11. Image Registration and Analysis for Quantitative Myocardial Perfusion: Application to Dynamic Circular Cardiac CT

    NARCIS (Netherlands)

    Isola, A.; Schmitt, H.; Van Stevendaal, U.; Begemann, P.G.C.; Coulon, P.; Boussel, L.; Grass, M.

    2012-01-01

    Large area detector computed tomography systems with fastrotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce X-ray dose andlimit motion artifacts. Even in the case

  12. Image Registration and Analysis for Quantitative Myocardial Perfusion: Application to Dynamic Circular Cardiac CT

    NARCIS (Netherlands)

    Isola, A.; Schmitt, H.; Van Stevendaal, U.; Begemann, P.G.C.; Coulon, P.; Boussel, L.; Grass, M.

    2012-01-01

    Large area detector computed tomography systems with fastrotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce X-ray dose andlimit motion artifacts. Even in the case

  13. 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.)

  14. Quantitative evaluation of perfusion magnetic resonance imaging hyper-acute ischemic stroke patients comparison with 1.5T and 3.0T units

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Eun Hoe [Dept. of Radiological Science, Cheongju University, Cheongju (Korea, Republic of); Moon, Il Bong; Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health University, Gwangju (Korea, Republic of)

    2017-02-15

    Perfusion magnetic resonance image of biological mechanism are independent of magnetic field strength in hyper acute ischemic stroke. 3.0 T magnetic field, however, does affect the SNRs (signal to noise ratio) and artifacts of PMRI (perfusion magnetic resonance image), which basically will influence the quantitative of PMRI. In this study, the effects of field strength on PMRI are analyzed. The effects of the diseases also are discussed. PMRI in WM (white matter), GM (gray matter), hyper acute ischemic stroke were companied with 1.5 T and 3.0 T on SNR. PMRI also was compared to the SI difference after setting ROI (region of interest) in left and right b side of the brain. In conclusion, the SNRs and SI of the 3.0 T PMRI showed higher than those at 1.5 T. In summary, PMRI studies at 3.0 T is provided significantly improved perfusion evaluation when comparing with 1.5 T.

  15. Dynamic contrast enhanced magnetic resonance perfusion imaging in high-risk smokers and smoking-related COPD: correlations with pulmonary function tests and quantitative computed tomography.

    Science.gov (United States)

    Xia, Yi; Guan, Yu; Fan, Li; Liu, Shi-Yuan; Yu, Hong; Zhao, Li-Ming; Li, Bing

    2014-09-01

    The study aimed to prospectively evaluate correlations between dynamic contrast-enhanced (DCE) MR perfusion imaging, pulmonary function tests (PFT) and volume quantitative CT in smokers with or without chronic obstructive pulmonary disease (COPD) and to determine the value of DCE-MR perfusion imaging and CT volumetric imaging on the assessment of smokers. According to the ATS/ERS guidelines, 51 male smokers were categorized into five groups: At risk for COPD (n = 8), mild COPD (n = 9), moderate COPD (n = 12), severe COPD (n = 10), and very severe COPD (n = 12). Maximum slope of increase (MSI), positive enhancement integral (PEI), etc. were obtained from MR perfusion data. The signal intensity ratio (RSI) of the PDs and normal lung was calculated (RSI = SIPD/SInormal). Total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were obtained from volumetric CT data. For "at risk for COPD," the positive rate of PDs on MR perfusion images was higher than that of abnormal changes on non-enhanced CT images (p < 0.05). Moderate-to-strong positive correlations were found between all the PFT parameters and SIPD, or RSI (r range 0.445∼0.683, p ≤ 0.001). TEV and EI were negatively correlated better with FEV1/FVC than other PFT parameters (r range -0.48 --0.63, p < 0.001). There were significant differences in RSI and SIPD between "at risk for COPD" and "very severe COPD," and between "mild COPD" and "very severe COPD". Thus, MR perfusion imaging may be a good approach to identify early evidence of COPD and may have potential to assist in classification of COPD.

  16. A quantitative assessment of heart phantom motion and its effect on myocardial perfusion SPECT images

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to study the image characteristics of motion artifacts and todetermine the relations of motion artifacts with varied motion types, and the inag-ing timings, frames, distances and directions during SPECT acquisition, a myocardialphantom filled with pertechnetate solution was used to simulate the patient motion.In nonreturning pattern, the simulation motion was timed at the 0°, -45° and -90°positions during the rotation of the detector over a 180° arc from +45° right antcrioroblique to -135° left posterior oblique. Simulation motion was performed by movingthe phantom +5mm, ±-10mm and +20mm along X- (from left to right), Y- (fromhead to caudal) and Z-axis (from back to ventral) respectively. In returning patternthe acquired 30 projections were divided into three equal parts. The simulation motionwas timed at the middle 1-7 projections of each part and performed by moving thephantom +5, ±10, ±15, ±20, ±25, ±30 and ±50 mm along X-, Y- and Z-axis respec-tively. Each image was compared with normal image and assessed by three experiencedobservers without knowledge of the phantom motion. Logistic regression analysis wasused to determine the relationship of motion artifacts with the affecting factors. Nosignificant artifacts can be found when the phantom was moved slightly, no matterwhich motion pattern, direction and timing were taken. The characteristics of motionartifacts showed a radioactive marker dot in inferior wall firstly when the phantomwas moved along X-axis. Septal and lateral wall became "hot" symmetrically whenthe phantom was moved along Y-axis. And nodular hot could be found in anteriorwall when the phantom was moved along Z-axis. At last the "lumpy" and "defect"areas existed alternately and formed a triangle respectively. The presence of motionartifacts was related to motion directions, distance and affected frames, but was in-dependent of motion timing. The characteristics of motion artifacts could be foundwhen the phantom was moved

  17. Quantitative evaluation of myocardial single-photon emission tomographic imaging: application to the measurement of perfusion defect size and severity.

    Science.gov (United States)

    Benoit, T; Vivegnis, D; Foulon, J; Rigo, P

    1996-12-01

    A new method is described for precise quantitative analysis of the relative three-dimensional distribution of myocardial tracers. The system uses a 360 degrees elliptical sampling of radial slices to create activity profiles. These are then positioned onto a common centre at the same angular coordinates as the corresponding radial slice reconstruction planes to generate a two-dimensional polar summary display. Abnormal distribution is then identified by automatic comparison of the patient polar map with the threshold of a normal database defined on a pixel by pixel basis as the normal mean -2.5 SD. Our stress and rest databases currently comprise 34 and 24 studies for sestamibi and tetrofosmin respectively. The present method differs from currently available software in two major respects. First, radial slices are used rather than short-axis slices to minimize operator intervention and to allow quantitative evaluation of the left ventricle volume independent of the heart size and without truncation, in particular near the apex and at the base. This sampling scheme also results in a more homogeneous and sampling-independent partial volume effect. Secondly, quantitative analysis is improved by calculating perfusion defect severity, extent and size in a precise manner. Severity is evaluated relative to a standardized background measurement and to the mean normal value rather than to the threshold value. This parameter was underestimated up to a defect extent of 32 cm2 in our phantom studies. Calculation of defect extent takes into account the surface distortion resulting from planar projection by using pixel by pixel weighted factors but it is otherwise overestimated as a result of the limited resolution of the imaging system. Integrating defect severity and extent, our hypoperfusion index appeared to accurately estimate the true defect size in our phantom model (r=0.993). The reproducibility of analysis was 6.24% in phantom studies and 3.10% in patient studies

  18. Comparison of quantitative perfusion imaging using arterial spin labeling at 1.5 and 4.0 Tesla.

    Science.gov (United States)

    Wang, Jiongjiong; Alsop, David C; Li, Lin; Listerud, John; Gonzalez-At, Julio B; Schnall, Mitchell D; Detre, John A

    2002-08-01

    High-field arterial spin labeling (ASL) perfusion MRI is appealing because it provides not only increased signal-to-noise ratio (SNR), but also advantages in terms of labeling due to the increased relaxation time T(1) of labeled blood. In the present study, we provide a theoretical framework for the dependence of the ASL signal on the static field strength, followed by experimental validation in which a multislice pulsed ASL (PASL) technique was carried out at 4T and compared with PASL and continuous ASL (CASL) techniques at 1.5T, both in the resting state and during motor activation. The resting-state data showed an SNR ratio of 2.3:1.4:1 in the gray matter and a contrast-to-noise ratio (CNR) of 2.7:1.1:1 between the gray and white matter for the difference perfusion images acquired using 4T PASL, 1.5T CASL, and 1.5T PASL, respectively. However, the functional data acquired using 4T PASL did not show significantly improved sensitivity to motor cortex activation compared with the 1.5T functional data, with reduced fractional perfusion signal change and increased intersubject variability. Possible reasons for these experimental results, including susceptibility effects and physiological noise, are discussed. Copyright 2002 Wiley-Liss, Inc.

  19. 肾透明细胞癌多层螺旋CT灌注成像血流灌注的定量诊断价值%Quantitative study of suprarenal epithelioma by CT perfusion imaging and blood perfusion

    Institute of Scientific and Technical Information of China (English)

    牛玉军; 张祥林

    2011-01-01

    Objective To approach quantitative diagnostic value of MSCT perfusion imaging in blood perfusion of suprarenal epithelioma.Methods 58 cases of MSCT perfusion imaging data of suprarenal epithelioma proved by operation were analyzed and blood perfusion imaging both cancer and normal nephridial tissue opposite side were demonstrated.Blood flow( BF), blood volume( BV), mean transit time (MTT) and permeability coefficient(PS) both in active part of tumor and normal nephridial tissue opposite side were calculated.Results There was significant statistical difference in BF, BV, MTT and PS between tumor and normal tissue ( P < 0.01 ).Conclusions MSCT perfusion imaging can complete the quantitative assessment to haemodynamics variation of suprarenal epithelioma and it also can reflect appearance and function of tumor and decide prognosis.%目的 探讨多层螺旋CT(MSCT)灌注成像对肾透明细胞癌血流灌注的定量诊断价值.方法 回顾性分析经手术病理证实的肾透明细胞癌58例MSCT灌注扫描数据,使用256彩色直观显示癌组织及对侧正常肾组织血流灌注图,分别计算出肿瘤生长活跃部分及对侧正常肾皮质血流量(BF)、血容量(BV)、对比剂平均通过时间(MTT)及毛细血管表面通透系数(PS),并进行对比分析、定量研究.结果 肿瘤生长活跃部分的BF、BV、MTT、PS与对侧肾皮质各灌注参数间均有显著差异(P<0.01).结论 MSCT灌注成像能定量评价肾透明细胞癌的血流动力学变化,同时反映肿瘤的形态和功能,并能判断预后.

  20. Quantitative perfusion imaging by multi-slice CT in stroke patients; Quantitative Perfusionsbildgebung mittels Mehrschicht-Spiral-CT bei Patienten mit akuter zerebraler Ischaemie

    Energy Technology Data Exchange (ETDEWEB)

    Bohner, G.; Klingebiel, R. [Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Abt. Neuroradiologie; Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Inst. fuer Radiologie; Foerschler, A.; Lehmann, R. [Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Abt. Neuroradiologie; Hamm, B. [Humboldt-Universitaet, Berlin (Germany). Universitaetsklinikum Charite, Inst. fuer Radiologie

    2003-06-01

    Objectives: Evaluation of a parametric deconvolution algorithm (DA) in the diagnostic assessment of stroke patients by multislice spiral computed tomography (MS-CT). Material and Methods: 52 patients (age range 34-89 years) with clinically suspected acute ischemia of one hemisphere and no infarct demarcation on plain cerebral CT underwent CT perfusion (CTP), performed on average 3.4 hours after the onset of symptoms by using MS-CT (4 x 8 mm scan volume). Using a DA-based software module, perfusion images of the cerebral blood perfusion (CBP), cerebral blood volume (CBV) and mean transit time (MTT) were calculated and assessed by two readers for visually apparent perfusion abnormalities. Amount and extension of perfusion disturbances were measured and correlated with the outcome. Results: Of 44 patients, in whom perfusion maps could be generated, territorial infarction was confirmed by follow-up in 22 subjects. With a sensitivity of 95% ischemia could be detected on MTT-maps (CBP 91%, CBV 77%). Specificity was highest (100%) for CBV-maps. Patients with infarction showed significant (p<0.001) reduction of CBP (10.7 vs. 38.3 ml/100 ml/min), CBV (1.3 vs. 2.3 ml/100 ml) and prolongation of MTT (12.3 vs. 4.3 s) compared to the contralateral hemisphere, whereas in patients without infarction no significant changes were found. Extension of CBV reduction showed the best correlation (r=0.82) with final infarct volume. Conclusion: The DA-based CTP protocol evaluated in this study is a suitable tool for the early identification and quantification of acute cerebral ischemia. (orig.) [German] Ziel: Evaluation des Einsatzes der Mehrschicht-Spiral-CT (MS-CT) in Kombination mit einem parametrischen Dekonvolutionsalgorithmus (DA) zur zerebralen Perfusionsbildgebung bei Patienten mit klinischen Zeichen einer akuten territorialen Ischaemie. Material und Methoden: 52 Patienten (Altersspanne 34-89 Jahre) mit klinischen Zeichen einer akuten territorialen Ischaemie sowie fehlender

  1. Applicability of quantitative optical imaging techniques for intraoperative perfusion diagnostics: a comparison of laser speckle contrast imaging, sidestream dark-field microscopy, and optical coherence tomography

    Science.gov (United States)

    Jansen, Sanne M.; de Bruin, Daniel M.; Faber, Dirk J.; Dobbe, Iwan J. G. G.; Heeg, Erik; Milstein, Dan M. J.; Strackee, Simon D.; van Leeuwen, Ton G.

    2017-08-01

    Patient morbidity and mortality due to hemodynamic complications are a major problem in surgery. Optical techniques can image blood flow in real-time and high-resolution, thereby enabling perfusion monitoring intraoperatively. We tested the feasibility and validity of laser speckle contrast imaging (LSCI), optical coherence tomography (OCT), and sidestream dark-field microscopy (SDF) for perfusion diagnostics in a phantom model using whole blood. Microvessels with diameters of 50, 100, and 400 μm were constructed in a scattering phantom. Perfusion was simulated by pumping heparinized human whole blood at five velocities (0 to 20 mm/s). Vessel diameter and blood flow velocity were assessed with LSCI, OCT, and SDF. Quantification of vessel diameter was feasible with OCT and SDF. LSCI could only visualize the 400-μm vessel, perfusion units scaled nonlinearly with blood velocity. OCT could assess blood flow velocity in terms of inverse OCT speckle decorrelation time. SDF was not feasible to measure blood flow; however, for diluted blood the measurements were linear with the input velocity up to 1 mm/s. LSCI, OCT, and SDF were feasible to visualize blood flow. Validated blood flow velocity measurements intraoperatively in the desired parameter (mL·g-1) remain challenging.

  2. Applicability of quantitative optical imaging techniques for intraoperative perfusion diagnostics: a comparison of laser speckle contrast imaging, sidestream dark-field microscopy, and optical coherence tomography.

    Science.gov (United States)

    Jansen, Sanne M; de Bruin, Daniel M; Faber, Dirk J; Dobbe, Iwan J G G; Heeg, Erik; Milstein, Dan M J; Strackee, Simon D; van Leeuwen, Ton G

    2017-08-01

    Patient morbidity and mortality due to hemodynamic complications are a major problem in surgery. Optical techniques can image blood flow in real-time and high-resolution, thereby enabling perfusion monitoring intraoperatively. We tested the feasibility and validity of laser speckle contrast imaging (LSCI), optical coherence tomography (OCT), and sidestream dark-field microscopy (SDF) for perfusion diagnostics in a phantom model using whole blood. Microvessels with diameters of 50, 100, and 400  μm were constructed in a scattering phantom. Perfusion was simulated by pumping heparinized human whole blood at five velocities (0 to 20  mm/s). Vessel diameter and blood flow velocity were assessed with LSCI, OCT, and SDF. Quantification of vessel diameter was feasible with OCT and SDF. LSCI could only visualize the 400-μm vessel, perfusion units scaled nonlinearly with blood velocity. OCT could assess blood flow velocity in terms of inverse OCT speckle decorrelation time. SDF was not feasible to measure blood flow; however, for diluted blood the measurements were linear with the input velocity up to 1  mm/s. LSCI, OCT, and SDF were feasible to visualize blood flow. Validated blood flow velocity measurements intraoperatively in the desired parameter (mL·min-1·g-1) remain challenging. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  3. 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.

  4. Personal computer aided cerebral perfusion imaging with dynamic CT

    Institute of Scientific and Technical Information of China (English)

    林燕; 高培毅

    2004-01-01

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

  5. Differential impact of multi-focus fan beam collimation with L-mode and conventional systems on the accuracy of myocardial perfusion imaging: Quantitative evaluation using phantoms

    Directory of Open Access Journals (Sweden)

    Tatsunori Saho

    2013-10-01

    Full Text Available Introduction: A novel IQ-SPECTTM method has become widely used in clinical studies. The present study compares the quality of myocardial perfusion images (MPI acquired using the IQ-SPECTTM (IQ-mode,conventional (180° apart: C-mode and L-mode (90° apart: L-mode systems. We assessed spatial resolution, image reproducibility and quantifiability using various physical phantoms. Materials and Methods: SPECT images were acquired using a dual-headed gamma camera with C-mode, L-mode, and IQ-mode acquisition systems from line source, pai and cardiac phantoms containing solutions of 99mTc. The line source phantom was placed in the center of the orbit and at ± 4.0, ± 8.0, ± 12.0, ± 16.0 and ± 20.0 cm off center. We examined quantifiability using the pai phantom comprising six chambers containing 0.0, 0.016, 0.03, 0.045, 0.062, and 0.074 MBq/mLof 99m-Tc and cross-calibrating the SPECT counts. Image resolution and reproducibility were quantified as myocardial wall thickness (MWT and %uptake using polar maps. Results: The full width at half maximum (FWHM of the IQ-mode in the center was increased by 11% as compared with C-mode, and FWHM in the periphery was increased 41% compared with FWHM at the center. Calibrated SPECT counts were essentially the same when quantified using IQ-and C-modes. IQ-SPECT images of MWT were significantly improved (P<0.001 over L-mode, and C-mode SPECT imaging with IQ-mode became increasingly inhomogeneous, both visually and quantitatively (C-mode vs. L-mode, ns; C-mode vs. IQ-mode, P<0.05. Conclusion: Myocardial perfusion images acquired by IQ-SPECT were comparable to those acquired by conventional and L-mode SPECT, but with significantly improved resolution and quality. Our results suggest that IQ-SPECT is the optimal technology for myocardial perfusion SPECT imaging.

  6. Dynamic MR imaging of osteoid osteomas: correlation of semiquantitative and quantitative perfusion parameters with patient symptoms and treatment outcome

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Pedro A.G. [Service D' imagerie Guilloz, CHU, Nancy (France); Universite de Lorraine, IADI, UMR S 947, Nancy (France); Pedro Augusto Gondim Teixeira, Jarville-la-Malgrange (France); Chanson, Anne; Lecocq, Sophie; Louis, Matthias [Service D' imagerie Guilloz, CHU, Nancy (France); Beaumont, Marine [Universite de Lorraine, IADI, UMR S 947, Nancy (France); Marie, Beatrice [Service d' anatomo-pathologie, CHU, Nancy (France); Sirveaux, Francois [Service de Chirurgie Traumatologique et Orthopedique, Centre Chirurgical Emile Galle, Nancy (France); Blum, Alain [Service D' imagerie Guilloz, CHU, Nancy (France); Universite de Lorraine, IADI, UMR S 947, Nancy (France)

    2013-09-15

    To evaluate the relationship between multiple MR perfusion parameters and symptoms of patients with osteoid osteomas after percutaneous laser therapy. MR perfusion studies of 20 patients diagnosed with an osteoid osteoma, treated with CT-guided percutaneous laser therapy, were retrospectively evaluated. Multiple perfusion parameters correlated with the treatment outcome and the presence of osteoid osteoma-related symptoms. There were 16 successful treatments, 6 recurrences and a significant difference in the perfusion parameters of these groups (P < 0.0001). Patients with successful treatment demonstrated delayed progressive enhancement or no enhancement (mean time to peak = 182 s, mean delay to the arterial peak = 119.3 s). Patients with treatment failure demonstrated an early and steep enhancement (mean time to peak = 78 s and mean delay to the arterial peak = 24 s). Plasmatic volume and transfer constant values significantly changed after successful treatment (P < 0.008). MR perfusion has a sensitivity and a specificity higher than 90 % in the detection of recurrent osteoid osteomas. The identification of an early and steep enhancement with short time to peak and a short delay between the arterial and nidus peaks on MR perfusion in the postoperative setting is highly indicative of an osteoid osteoma recurrence. (orig.)

  7. Diagnostic accuracy of stress perfusion CMR in comparison with quantitative coronary angiography: fully quantitative, semiquantitative, and qualitative assessment.

    Science.gov (United States)

    Mordini, Federico E; Haddad, Tariq; Hsu, Li-Yueh; Kellman, Peter; Lowrey, Tracy B; Aletras, Anthony H; Bandettini, W Patricia; Arai, Andrew E

    2014-01-01

    This study's primary objective was to determine the sensitivity, specificity, and accuracy of fully quantitative stress perfusion cardiac magnetic resonance (CMR) versus a reference standard of quantitative coronary angiography. We hypothesized that fully quantitative analysis of stress perfusion CMR would have high diagnostic accuracy for identifying significant coronary artery stenosis and exceed the accuracy of semiquantitative measures of perfusion and qualitative interpretation. Relatively few studies apply fully quantitative CMR perfusion measures to patients with coronary disease and comparisons to semiquantitative and qualitative methods are limited. Dual bolus dipyridamole stress perfusion CMR exams were performed in 67 patients with clinical indications for assessment of myocardial ischemia. Stress perfusion images alone were analyzed with a fully quantitative perfusion (QP) method and 3 semiquantitative methods including contrast enhancement ratio, upslope index, and upslope integral. Comprehensive exams (cine imaging, stress/rest perfusion, late gadolinium enhancement) were analyzed qualitatively with 2 methods including the Duke algorithm and standard clinical interpretation. A 70% or greater stenosis by quantitative coronary angiography was considered abnormal. The optimum diagnostic threshold for QP determined by receiver-operating characteristic curve occurred when endocardial flow decreased to qualitative methods: Duke algorithm: 70%; and clinical interpretation: 78% (p quantitative stress perfusion CMR has high diagnostic accuracy for detecting obstructive coronary artery disease. QP outperforms semiquantitative measures of perfusion and qualitative methods that incorporate a combination of cine, perfusion, and late gadolinium enhancement imaging. These findings suggest a potential clinical role for quantitative stress perfusion CMR. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  8. Simulation evaluation of quantitative myocardial perfusion assessment from cardiac CT

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2014-03-01

    Contrast enhancement on cardiac CT provides valuable information about myocardial perfusion and methods have been proposed to assess perfusion with static and dynamic acquisitions. There is a lack of knowledge and consensus on the appropriate approach to ensure 1) sufficient diagnostic accuracy for clinical decisions and 2) low radiation doses for patient safety. This work developed a thorough dynamic CT simulation and several accepted blood flow estimation techniques to evaluate the performance of perfusion assessment across a range of acquisition and estimation scenarios. Cardiac CT acquisitions were simulated for a range of flow states (Flow = 0.5, 1, 2, 3 ml/g/min, cardiac output = 3,5,8 L/min). CT acquisitions were simulated with a validated CT simulator incorporating polyenergetic data acquisition and realistic x-ray flux levels for dynamic acquisitions with a range of scenarios including 1, 2, 3 sec sampling for 30 sec with 25, 70, 140 mAs. Images were generated using conventional image reconstruction with additional image-based beam hardening correction to account for iodine content. Time attenuation curves were extracted for multiple regions around the myocardium and used to estimate flow. In total, 2,700 independent realizations of dynamic sequences were generated and multiple MBF estimation methods were applied to each of these. Evaluation of quantitative kinetic modeling yielded blood flow estimates with an root mean square error (RMSE) of ~0.6 ml/g/min averaged across multiple scenarios. Semi-quantitative modeling and qualitative static imaging resulted in significantly more error (RMSE = ~1.2 and ~1.2 ml/min/g respectively). For quantitative methods, dose reduction through reduced temporal sampling or reduced tube current had comparable impact on the MBF estimate fidelity. On average, half dose acquisitions increased the RMSE of estimates by only 18% suggesting that substantial dose reductions can be employed in the context of quantitative myocardial

  9. 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)

  10. Quantitative evaluation of myocardial single-photon emission tomographic imaging: application to the measurement of perfusion defect size and severity

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, T. [Division of Nuclear Medicine, C.H.U. Sart Tilman, Liege (Belgium); Vivegnis, D. [Division of Nuclear Medicine, C.H.U. Sart Tilman, Liege (Belgium); Foulon, J. [Division of Nuclear Medicine, C.H.U. Sart Tilman, Liege (Belgium); Rigo, P. [Division of Nuclear Medicine, C.H.U. Sart Tilman, Liege (Belgium)

    1996-12-01

    A new method is described for precise quantitative analysis of the relative three-dimensional distribution of myocardial tracers. The system uses a 360 elliptical sampling of radial slices to create activity profiles. These are then positioned onto a common centre at the same angular coordinates as the corresponding radial slice reconstruction planes to generate a two-dimensional polar summary display. Abnormal distribution is then identified by automatic comparison of the patient polar map with the threshold of a normal database defined on a pixel by pixel basis as the normal mean -2.5 SD. Our stress and rest databases currently comprise 34 and 24 studies for sestamibi and tetrofosmin respectively. The present method differs from currently available software in two major respects. Calculation of defect extent takes into account the surface distortion resulting from planar projection by using pixel by pixel weighted factors but it is otherwise overestimated as a result of the limited resolution of the imaging system. Integrating defect severity and extent, our hypoperfusion index appeared to accurately estimate the true defect size in our phantom model (r=0.993). The reproducibility of analysis was 6.24% in phantom studies and 3.10% in patient studies including repeated acquisitions. Applied to a well-documented population of 80 patients, this method resulted in an 86% sensitivity and a 78% specificity for overall coronary artery disease detection with reference to the angiographic data. (orig.). With 14 figs., 2 tabs.

  11. Diffusion and perfusion imaging of bone marrow

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  12. CT perfusion image processing: analysis of liver tumors

    OpenAIRE

    D’Antò, Michela

    2013-01-01

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

  13. Effects of CT-based attenuation correction of rat microSPECT images on relative myocardial perfusion and quantitative tracer uptake

    Energy Technology Data Exchange (ETDEWEB)

    Strydhorst, Jared H., E-mail: jared.strydhorst@gmail.com; Ruddy, Terrence D.; Wells, R. Glenn [Cardiac Imaging, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada)

    2015-04-15

    Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with {sup 99m}Tc and {sup 201}Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with {sup 99m}Tc-tetrofosmin and scanned in a small animal pinhole SPECT/CT scanner. Scans were repeated weekly over a period of 5 weeks. Eight additional rats were injected with {sup 201}Tl and also scanned following a similar protocol. The images were reconstructed with and without attenuation correction, and the relative perfusion was analyzed with the commercial cardiac analysis software. The absolute uptake of {sup 99m}Tc in the heart was also quantified with and without attenuation correction. Results: For {sup 99m}Tc imaging, relative segmental perfusion changed by up to +2.1%/−1.8% as a result of attenuation correction. Relative changes of +3.6%/−1.0% were observed for the {sup 201}Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected {sup 99m}Tc scans, and 3.6% and 4.3%, respectively, for the {sup 201}Tl scans, and were not significantly affected by attenuation correction for either tracer. Attenuation correction also significantly increased the measured absolute uptake of tetrofosmin and significantly altered the relationship between the rat weight and tracer uptake. Conclusions: Our results show that attenuation correction has a small but statistically significant impact on the relative perfusion measurements in some segments of the heart and does not adversely affect reproducibility. Attenuation correction had a small but statistically significant impact on measured absolute tracer uptake.

  14. Assessment of differential pulmonary blood flow using perfusion magnetic resonance imaging: comparison with radionuclide perfusion scintigraphy.

    Science.gov (United States)

    Molinari, Francesco; Fink, Christian; Risse, Frank; Tuengerthal, Siegfried; Bonomo, Lorenzo; Kauczor, Hans-Ulrich

    2006-08-01

    We sought to assess the agreement between lung perfusion ratios calculated from pulmonary perfusion magnetic resonance imaging (MRI) and those calculated from radionuclide (RN) perfusion scintigraphy. A retrospective analysis of MR and RN perfusion scans was conducted in 23 patients (mean age, 60 +/- 14 years) with different lung diseases (lung cancer = 15, chronic obstructive pulmonary disease = 4, cystic fibrosis = 2, and mesothelioma = 2). Pulmonary perfusion was assessed by a time-resolved contrast-enhanced 3D gradient-echo pulse sequence using parallel imaging and view sharing (TR = 1.9 milliseconds; TE = 0.8 milliseconds; parallel imaging acceleration factor = 2; partition thickness = 4 mm; matrix = 256 x 96; in-plane spatial resolution = 1.87 x 3.75 mm; scan time for each 3D dataset = 1.5 seconds), using gadolinium-based contrast agents (injection flow rate = 5 mL/s, dose = 0.1 mmol/kg of body weight). The peak concentration (PC) of the contrast agent bolus, the pulmonary blood flow (PBF), and blood volume (PBV) were computed from the signal-time curves of the lung. Left-to-right ratios of pulmonary perfusion were calculated from the MR parameters and RN counts. The agreement between these ratios was assessed for side prevalence (sign test) and quantitatively (Deming-regression). MR and RN ratios agreed on side prevalence in 21 patients (91%) with PC, in 20 (87%) with PBF, and in 17 (74%) with PBV. The MR estimations of left-to-right perfusion ratios correlated significantly with those of RN perfusion scans (P lung. Further studies in a larger group of patients are required to fully confirm the clinical suitability of this imaging method.

  15. Coronary calcium score scans for attenuation correction of quantitative PET/CT {sup 13}N-ammonia myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Burkhard, Nina; Herzog, Bernhard A.; Husmann, Lars; Pazhenkottil, Aju P.; Burger, Irene A.; Buechel, Ronny R.; Valenta, Ines; Wyss, Christophe A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology, Zurich (Switzerland)

    2010-03-15

    The aim of this study was to evaluate whether ECG-triggered coronary calcium scoring (CCS) scans can be used for attenuation correction (AC) to quantify myocardial blood flow (MBF) and coronary flow reserve (CFR) assessed by PET/CT with {sup 13}N-ammonia. Thirty-five consecutive patients underwent a {sup 13}N-ammonia PET/CT scan at rest and during standard adenosine stress. MBF values were calculated using AC maps obtained from the ECG-triggered CCS scan during inspiration and validated against MBF values calculated using standard non-gated transmission scans for AC. CFR was calculated as the ratio of hyperaemic over resting MBF. In all 35 consecutive patients intraobserver variability was assessed by blinded repeat analysis for both AC methods. There was an excellent correlation between CT AC and CCS for global MBF values at rest (n = 35, r = 0.94, p < 0.001) and during stress (n = 35, r = 0.97, p < 0.001) with narrow Bland-Altman (BA) limits of agreement (-0.21 to 0.10 ml/min per g and -0.41 to 0.30 ml/min per g) as well as for global CFR (n = 35, r = 0.96, p < 0.001, BA -0.27 to 0.34). The excellent correlation was preserved on the segmental MBF analysis for both rest and stress (n = 1190, r = 0.93, p < 0.001, BA -0.60 to 0.50) and for CFR (n = 595, r = 0.87, p < 0.001, BA -0.71 to 0.74). In addition, reproducibility proved excellent for global CFR by CT AC (n = 35, r = 0.91, p < 0.001, BA -0.42-0.58) and CCS scans (n = 35, r = 0.94, p < 0.001, BA -0.34-0.45). Use of attenuation maps from CCS scans allows accurate quantitative MBF and CFR assessment with {sup 13}N-ammonia PET/CT. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

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

    DEFF Research Database (Denmark)

    Minarik, David; Senneby, Martin; Wollmer, Per

    2015-01-01

    Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...... for further assisting the visual interpretation and to test the concept using simulated MPS images as well as patients. Methods The perfusion vector is based on calculating the difference between the anatomical centroid and the perfusion center of gravity of the left ventricle. Simulated MPS images were.......001) but not for patients with infarction. The correlation between the defect size and stress vector magnitude was also found to be significant (p concept of the perfusion vector introduced in this study is shown to have potential in assisting the visual interpretation in MPS studies. Further...

  18. High temporal versus high spatial resolution in MR quantitative pulmonary perfusion imaging of two-year old children after congenital diaphragmatic hernia repair

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, M.; Hagelstein, C.; Schoenberg, S.O.; Neff, K.W. [University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, Mannheim (Germany); Zoellner, F.G.; Schad, L.R. [Heidelberg University, Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Mannheim (Germany); Zahn, K. [University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Department of Pediatric Surgery, Mannheim (Germany); Schaible, T. [University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Department of Pediatrics, Mannheim (Germany)

    2014-10-15

    Congenital diaphragmatic hernia (CDH) leads to lung hypoplasia. Using dynamic contrast-enhanced (DCE) MR imaging, lung perfusion can be quantified. As MR perfusion values depend on temporal resolution, we compared two protocols to investigate whether ipsilateral lung perfusion is impaired after CDH, whether there are protocol-dependent differences, and which protocol is preferred. DCE-MRI was performed in 36 2-year old children after CDH on a 3 T MRI system; protocol A (n = 18) based on a high spatial (3.0 s; voxel: 1.25 mm{sup 3}) and protocol B (n = 18) on a high temporal resolution (1.5 s; voxel: 2 mm{sup 3}). Pulmonary blood flow (PBF), pulmonary blood volume (PBV), mean transit time (MTT), and peak-contrast-to-noise-ratio (PCNR) were quantified. PBF was reduced ipsilaterally, with ipsilateral PBF of 45 ± 26 ml/100 ml/min to contralateral PBF of 63 ± 28 ml/100 ml/min (p = 0.0016) for protocol A; and for protocol B, side differences were equivalent (ipsilateral PBF = 62 ± 24 vs. contralateral PBF = 85 ± 30 ml/100 ml/min; p = 0.0034). PCNR was higher for protocol B (30 ± 18 vs. 20 ± 9; p = 0.0294). Protocol B showed higher values of PBF in comparison to protocol A (p always <0.05). Ipsilateral lung perfusion is reduced in 2-year old children following CDH repair. Higher temporal resolution and increased voxel size show a gain in PCNR and lead to higher perfusion values. Protocol B is therefore preferred. (orig.)

  19. 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.

  20. Quantitative analysis of a scar's pliability, perfusion and metrology

    Science.gov (United States)

    Gonzalez, Mariacarla; Sevilla, Nicole; Chue-Sang, Joseph; Ramella-Roman, Jessica C.

    2017-02-01

    The primary effect of scarring is the loss of function in the affected area. Scarring also leads to physical and psychological problems that could be devastating to the patient's life. Currently, scar assessment is highly subjective and physician dependent. The examination relies on the expertise of the physician to determine the characteristics of the scar by touch and visual examination using the Vancouver scar scale (VSS), which categorizes scars depending on pigmentation, pliability, height and vascularity. In order to establish diagnostic guidelines for scar formation, a quantitative, accurate assessment method needs to be developed. An instrument capable of measuring all categories was developed; three of the aforementioned parameters will be explored. In order to look at pliability, a durometer which measures the amount of resistance a surface exerts to prevent the permanent indentation of the surface is used due to its simplicity and quantitative output. To look at height and vascularity, a profilometry system that collects the location of the scar in three-dimensions and laser speckle imaging (LSI), which shows the dynamic changes in perfusion, respectively, are used. Gelatin phantoms were utilized to measure pliability. Finally, dynamic changes in skin perfusion of volunteers' forearms undergoing pressure cuff occlusion were measured, along with incisional scars.

  1. 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...

  2. Standardized perfusion value of the esophageal carcinoma and its correlation with quantitative CT perfusion parameter values

    Energy Technology Data Exchange (ETDEWEB)

    Djuric-Stefanovic, A., E-mail: avstefan@eunet.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Saranovic, Dj., E-mail: crvzve4@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Sobic-Saranovic, D., E-mail: dsobic2@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia); Masulovic, D., E-mail: draganmasulovic@yahoo.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Artiko, V., E-mail: veraart@beotel.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia)

    2015-03-15

    Purpose: Standardized perfusion value (SPV) is a universal indicator of tissue perfusion, normalized to the whole-body perfusion, which was proposed to simplify, unify and allow the interchangeability among the perfusion measurements and comparison between the tumor perfusion and metabolism. The aims of our study were to assess the standardized perfusion value (SPV) of the esophageal carcinoma, and its correlation with quantitative CT perfusion measurements: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) of the same tumor volume samples, which were obtained by deconvolution-based CT perfusion analysis. Methods: Forty CT perfusion studies of the esophageal cancer were analyzed, using the commercial deconvolution-based CT perfusion software (Perfusion 3.0, GE Healthcare). The SPV of the esophageal tumor and neighboring skeletal muscle were correlated with the corresponding mean tumor and muscle quantitative CT perfusion parameter values, using Spearman's rank correlation coefficient (r{sub S}). Results: Median SPV of the esophageal carcinoma (7.1; range: 2.8–13.4) significantly differed from the SPV of the skeletal muscle (median: 1.0; range: 0.4–2.4), (Z = −5.511, p < 0.001). The cut-off value of the SPV of 2.5 enabled discrimination of esophageal cancer from the skeletal muscle with sensitivity and specificity of 100%. SPV of the esophageal carcinoma significantly correlated with corresponding tumor BF (r{sub S} = 0.484, p = 0.002), BV (r{sub S} = 0.637, p < 0.001) and PS (r{sub S} = 0.432, p = 0.005), and SPV of the skeletal muscle significantly correlated with corresponding muscle BF (r{sub S} = 0.573, p < 0.001), BV (r{sub S} = 0.849, p < 0.001) and PS (r{sub S} = 0.761, p < 0.001). Conclusions: We presented a database of the SPV for the esophageal cancer and proved that SPV of the esophageal neoplasm significantly differs from the SPV of the skeletal muscle, which represented a sample of healthy

  3. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    Science.gov (United States)

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

  4. Quantitative pulmonary perfusion imaging at 3.0 T of 2-year-old children after congenital diaphragmatic hernia repair: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, F.G.; Schad, L.R. [Heidelberg University, Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Mannheim (Germany); Zahn, K. [Heidelberg University, Department of Pediatric Surgery, University Medical Center Mannheim, Mannheim (Germany); Schaible, T. [Heidelberg University, Department of Pediatrics, University Medical Center Mannheim, Mannheim (Germany); Schoenberg, S.O.; Neff, K.W. [Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim (Germany)

    2012-12-15

    To investigate whether dynamic contrast-enhanced MR imaging of the lung following congenital diaphragmatic hernia repair is feasible at 3.0 T in 2-year-old children and whether associated lung hypoplasia (reflected in reduced pulmonary microcirculation) can be demonstrated in MRI. Twelve children with a mean age 2.0 {+-} 0.2 years after hernia repair underwent DCE-MRI at 3.0 T using a time-resolved angiography with stochastic trajectories sequence. Quantification of lung perfusion was performed using a pixel-by-pixel deconvolution approach. Six regions of interest were placed (upper, middle and lower parts of right and left lung) to assess differences in pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) while avoiding the inclusion of larger pulmonary arteries and veins. The difference in PBF and PBV between ipsilateral and contralateral lung was significant (P < 0.5). No significant differences could be detected for the MTT (P = 0.5). DCE-MRI in 2-year-old patients is feasible at 3.0 T. Reduced perfusion in the ipsilateral lung is reflected by significantly lower PBF values compared with the contralateral lung. DCE-MRI of the lung in congenital diaphragmatic hernia can help to characterise lung hypoplasia initially and in the long-term follow-up of children after diaphragmatic repair. (orig.)

  5. 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 characteristic...

  6. 64-row MDCT perfusion of head and neck squamous cell carcinoma: technical feasibility and quantitative analysis of perfusion parameters

    Energy Technology Data Exchange (ETDEWEB)

    Faggioni, Lorenzo; Neri, Emanuele; Cerri, Francesca; Picano, Eugenia; Bartolozzi, Carlo [University of Pisa, Diagnostic and Interventional Radiology, Pisa (Italy); Seccia, Veronica; Muscatello, Luca; Franceschini, Stefano Sellari [University of Pisa, Division of Otorhinolaryngology, Pisa (Italy)

    2011-01-15

    To evaluate the technical feasibility of 64-row computed tomography (CT) quantitative perfusion imaging of head and neck squamous cell carcinoma (SCC). Twenty-nine patients with a total of 29 pathologically proven SCC underwent a cine-mode CT perfusion acquisition covering the lesion site. The acquisition started 10 s after intravenous injection of iodinated contrast material and lasted 50 s. On a dedicated workstation, regions of interest (ROI) were traced within the SCC, on a healthy portion of tissue (H), and on the ipsilateral sternocleidomastoid muscle (M). Blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability-surface product (PS) were calculated. In SCC, BF, BV and PS were higher compared with H (p < 0.0001, p = 0.002 and p = 0.004, respectively) and M (p < 0.0001). Conversely, MTT was lower in SCC than in H (p = 0.0009) and M (p = 0.0003). All datasets were free from substantial motion artefacts and ROI misregistration phenomena. No substantial discomfort or adverse events were experienced by any of the patients. 64-row CT quantitative perfusion imaging allows head and neck SCC to be distinguished from normal tissues. (orig.)

  7. 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.

  8. Performance of simultaneous high temporal resolution quantitative perfusion imaging of bladder tumors and conventional multi-phase urography using a novel free-breathing continuously acquired radial compressed-sensing MRI sequence.

    Science.gov (United States)

    Parikh, Nainesh; Ream, Justin M; Zhang, Hoi Cheung; Block, Kai Tobias; Chandarana, Hersh; Rosenkrantz, Andrew B

    2016-06-01

    To investigate the feasibility of high temporal resolution quantitative perfusion imaging of bladder tumors performed simultaneously with conventional multi-phase MR urography (MRU) using a novel free-breathing continuously acquired radial MRI sequence with compressed-sensing reconstruction. 22 patients with bladder lesions underwent MRU using GRASP (Golden-angle RAdial Sparse Parallel) acquisition. Multi-phase contrast-enhanced abdominopelvic GRASP was performed during free-breathing (1.4×1.4×3.0mm(3) voxel size; 3:44min acquisition). Two dynamic datasets were retrospectively reconstructed by combining different numbers of sequentially acquired spokes into each dynamic frame: 110 spokes per frame for 25-s temporal resolution (serving as conventional MRU for clinical interpretation) and 8 spokes per frame for 1.7-s resolution. Using 1.7-s resolution images, ROIs were placed within bladder lesions and normal bladder wall, a femoral artery arterial input function was generated, and the Generalized Kinetic Model was applied. Biopsy/cystectomy demonstrated 16 bladder tumors (13 stage≥T2, 3 stage≤T1) and 6 benign lesions. All lesions were well visualized using 25-s clinical multi-phase images. Using 1.7-s resolution images, K(trans) was significantly higher in tumors (0.38±0.24) than normal bladder (0.12±0.02=8, pMRU examinations using only one contrast injection and without additional scan time. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. 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.)

  10. Perfusion and metabolism imaging studies in Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per

    2012-01-01

    Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are important tools in the evaluation of brain blood flow and glucose metabolism in Parkinson's disease (PD). However, conflicting results are reported in the literature depending on the type of imaging data...... analysis employed. The present review gives a comprehensive summary of the perfusion and metabolism literature in the field of PD research, including quantitative PET studies, normalized PET and SPECT studies, autoradiography studies in animal models of PD, and simulation studies of PD data...

  11. Quantitative Susceptibility Mapping and Dynamic Contrast Enhanced Quantitative Perfusion in Cerebral Cavernous Angiomas

    Science.gov (United States)

    Mikati, Abdul Ghani; Tan, Huan; Shenkar, Robert; Li, Luying; Zhang, Lingjiao; Guo, Xiaodong; Shi, Changbin; Liu, Tian; Wang, Yi; Shah, Akash; Edelman, Robert; Christoforidis, Gregory; Awad, Issam

    2015-01-01

    Background Hyperpermeability and iron deposition are two central pathophysiological phenomena in human cerebral cavernous malformation (CCM) disease. Here we used two novel magnetic resonance imaging (MRI) techniques to establish a relationship between these phenomena. Methods Subjects with CCM disease (4 sporadic and 18 familial) underwent MRI imaging using the Dynamic Contrast Enhanced Quantitative Perfusion (DCEQP) and Quantitative Susceptibility Mapping (QSM) techniques that measure hemodynamic factors of vessel leak and iron deposition respectively, previously demonstrated in CCM disease. Regions of interest encompassing the CCM lesions were analyzed using these techniques Results Susceptibility measured by QSM was positively correlated with permeability of lesions measured using DCEQP (r=0.49, p=<0.0001). The correlation was not affected by factors including familial predisposition, lesion volume, the contrast agent and the use of statin medication. Susceptibility was correlated with lesional blood volume (r=0.4, p=0.0001), but not with lesional blood flow. Conclusion The correlation between QSM and DCEQP suggests that the phenomena of permeability and iron deposition are related in CCM; hence “more leaky lesions” also manifest a more cumulative iron burden. These techniques might be used as biomarkers to monitor the course of this disease and the effect of therapy. PMID:24302484

  12. Twente Optical Perfusion Camera: system overview and performance for video rate laser Doppler perfusion imaging

    NARCIS (Netherlands)

    M. Draijer; E. Hondebrink; T. van Leeuwen; W. Steenbergen

    2009-01-01

    We present the Twente Optical Perfusion Camera (TOPCam), a novel laser Doppler Perfusion Imager based on CMOS technology. The tissue under investigation is illuminated and the resulting dynamic speckle pattern is recorded with a high speed CMOS camera. Based on an overall analysis of the signal-to-n

  13. Twente Optical Perfusion Camera: system overview and performance for video rate laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Draijer, M.; Hondebrink, E.; van Leeuwen, T.; Steenbergen, W.

    2009-01-01

    We present the Twente Optical Perfusion Camera (TOPCam), a novel laser Doppler Perfusion Imager based on CMOS technology. The tissue under investigation is illuminated and the resulting dynamic speckle pattern is recorded with a high speed CMOS camera. Based on an overall analysis of the

  14. UMMPerfusion: an open source software tool towards quantitative MRI perfusion analysis in clinical routine.

    Science.gov (United States)

    Zöllner, Frank G; Weisser, Gerald; Reich, Marcel; Kaiser, Sven; Schoenberg, Stefan O; Sourbron, Steven P; Schad, Lothar R

    2013-04-01

    To develop a generic Open Source MRI perfusion analysis tool for quantitative parameter mapping to be used in a clinical workflow and methods for quality management of perfusion data. We implemented a classic, pixel-by-pixel deconvolution approach to quantify T1-weighted contrast-enhanced dynamic MR imaging (DCE-MRI) perfusion data as an OsiriX plug-in. It features parallel computing capabilities and an automated reporting scheme for quality management. Furthermore, by our implementation design, it could be easily extendable to other perfusion algorithms. Obtained results are saved as DICOM objects and directly added to the patient study. The plug-in was evaluated on ten MR perfusion data sets of the prostate and a calibration data set by comparing obtained parametric maps (plasma flow, volume of distribution, and mean transit time) to a widely used reference implementation in IDL. For all data, parametric maps could be calculated and the plug-in worked correctly and stable. On average, a deviation of 0.032 ± 0.02 ml/100 ml/min for the plasma flow, 0.004 ± 0.0007 ml/100 ml for the volume of distribution, and 0.037 ± 0.03 s for the mean transit time between our implementation and a reference implementation was observed. By using computer hardware with eight CPU cores, calculation time could be reduced by a factor of 2.5. We developed successfully an Open Source OsiriX plug-in for T1-DCE-MRI perfusion analysis in a routine quality managed clinical environment. Using model-free deconvolution, it allows for perfusion analysis in various clinical applications. By our plug-in, information about measured physiological processes can be obtained and transferred into clinical practice.

  15. Magnetic Resonance Perfusion Imaging in the Study of Language

    Science.gov (United States)

    Hillis, Argye E.

    2007-01-01

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

  16. Method, apparatus and software for analyzing perfusion images

    NARCIS (Netherlands)

    Spreeuwers, Lieuwe Jan; Breeuwer, Marcel

    2007-01-01

    The invention relates to a method for analyzing perfusion images, in particular MR pertbsion images, of a human or animal organ including the steps of: (a) defining at least one contour of the organ, and (b) establishing at least one perfusion parameter of a region of interest of said organ within a

  17. Method, apparatus and software for analyzing perfusion images

    NARCIS (Netherlands)

    Spreeuwers, Lieuwe Jan; Breeuwer, Marcel

    2004-01-01

    The invention relates to a method for analyzing perfusion images, in particular MR pertbsion images, of a human or animal organ including the steps of: (a) defining at least one contour of the organ, and (b) establishing at least one perfusion parameter of a region of interest of said organ within a

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

    Directory of Open Access Journals (Sweden)

    Semra Özdemir

    2013-08-01

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

  19. Semi-quantitative myocardial perfusion measured by computed tomography in patients with refractory angina

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Kühl, Jørgen Tobias; Kjaer, Andreas

    2017-01-01

    INTRODUCTION: Computed tomography (CT) is a novel method for assessment of myocardial perfusion and has not yet been compared to rubidium-82 positron emission tomography (PET). We aimed to compare CT measured semi-quantitative myocardial perfusion with absolute quantified myocardial perfusion using...

  20. Experimental Study of Multi-slice Spiral CT Perfusion Imaging in VX2 Soft-tissue Tumor of Rabbits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jingfeng; WANG Renfa; WANG Min; LI Yonggang; YANG Haitao

    2006-01-01

    An experimental animal model of malignant soft-tissue tumor was established to investigate the applied value of multi-slice spiral CT perfusion imaging preliminarily. Ten New Zealand white rabbits which were implanted with VX2 tumor in either proximal thigh were subjected to CT plain scan and perfusion scan two weeks later respectively, then the original perfusion images were transmitted to AW4.0 Workstation. The functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS) were computed and analyzed. All the values of BF, BV and PS in VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those in the normal muscular tissues significantly. It was suggested that multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, and can give a quantitative assessment to angiogenesis and blood perfusion of soft-tissue tumors.

  1. Quasi-simultaneous multimodal imaging of cutaneous tissue oxygenation and perfusion

    Science.gov (United States)

    Ren, Wenqi; Gan, Qi; Wu, Qiang; Zhang, Shiwu; Xu, Ronald

    2015-12-01

    Simultaneous and quantitative assessment of multiple tissue parameters may facilitate more effective diagnosis and therapy in many clinical applications, such as wound healing. However, existing wound assessment methods are typically subjective and qualitative, with the need for sequential data acquisition and coregistration between modalities, and lack of reliable standards for performance evaluation or calibration. To overcome these limitations, we developed a multimodal imaging system for quasi-simultaneous assessment of cutaneous tissue oxygenation and perfusion in a quantitative and noninvasive fashion. The system integrated multispectral and laser speckle imaging technologies into one experimental setup. Tissue oxygenation and perfusion were reconstructed by advanced algorithms. The accuracy and reliability of the imaging system were quantitatively validated in calibration experiments and a tissue-simulating phantom test. The experimental results were compared with a commercial oxygenation and perfusion monitor. Dynamic detection of cutaneous tissue oxygenation and perfusion was also demonstrated in vivo by a postocclusion reactive hyperemia procedure in a human subject and a wound healing process in a wounded mouse model. Our in vivo experiments not only validated the performance of the multimodal imaging system for cutaneous tissue oxygenation and perfusion imaging but also demonstrated its technical potential for wound healing assessment in clinical practice.

  2. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-15

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

  3. 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.

  4. 4D micro-CT-based perfusion imaging in small animals

    Science.gov (United States)

    Badea, C. T.; Johnston, S. M.; Lin, M.; Hedlund, L. W.; Johnson, G. A.

    2009-02-01

    Quantitative in-vivo imaging of lung perfusion in rodents can provide critical information for preclinical studies. However, the combined challenges of high temporal and spatial resolution have made routine quantitative perfusion imaging difficult in rodents. We have recently developed a dual tube/detector micro-CT scanner that is well suited to capture first-pass kinetics of a bolus of contrast agent used to compute perfusion information. Our approach is based on the paradigm that the same time density curves can be reproduced in a number of consecutive, small (i.e. 50μL) injections of iodinated contrast agent at a series of different angles. This reproducibility is ensured by the high-level integration of the imaging components of our system, with a micro-injector, a mechanical ventilator, and monitoring applications. Sampling is controlled through a biological pulse sequence implemented in LabVIEW. Image reconstruction is based on a simultaneous algebraic reconstruction technique implemented on a GPU. The capabilities of 4D micro-CT imaging are demonstrated in studies on lung perfusion in rats. We report 4D micro-CT imaging in the rat lung with a heartbeat temporal resolution of 140 ms and reconstructed voxels of 88 μm. The approach can be readily extended to a wide range of important preclinical models, such as tumor perfusion and angiogenesis, and renal function.

  5. Quantitative myocardial perfusion PET combined with coronary anatomy derived from CT angiography. Validation of a new fusion and visualisation software

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Harald; Weise, Reiner; Burchert, Wolfgang; Fricke, Eva [Inst. of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Centre North Rhine-Westphalia, Ruhr-Univ. Bochum, Bad Oeynhausen (Germany); Elsner, Andreas; Bolte, Matthias; Domik, Gitta [Research Group Computergraphics, Visualization and Image Processing, Univ. of Paderborn (Germany); Hoff, Joerg van den [PET Center, Inst. of Radiopharmacy, Research Center Rossendorf, Dresden (Germany)

    2009-07-01

    Aim: Dynamic perfusion PET offers a clinical relevant advantage over myocardial perfusion scintigraphy due to its ability to measure myocardial blood flow quantitatively. This leads to an improved detection of multivessel disease and the possibility to assess not only the culprit lesion but lower grade stenoses as well. For appropriate revascularization, perfusion defects must be matched to coronary lesions. It has been shown that image fusion of morphological and functional images is superior to side-by-side analysis. Still, software for quantitative perfusion PET combined with CT angiography is rare. In this paper we present a new software tool for image fusion and visualization of quantitative perfusion PET and coronary morphology derived from CT angiography. Methods: In our software, a PET uptake image is used for manual co-registration. Co-registration results are then applied to the functional data derived from compartment modelling. To evaluate the reproducibility of the manual co-registration, we calculated the deviation between a series of manual co-registrations performed on nine pairs of unregistered PET and CT datasets by five trained participants. Two dimensional transfer functions were used to highlight the coronary arteries from the CT study in the combined data sets. Results: The average Euclidian distances for three references points were between 3.7 and 4.1 mm. The maximum distance was 10.6 mm. By the use of the two dimensional transfer functions, coronary anatomy could be easily visualised either by user-interaction or automatically by use of neuronal networks. Conclusions: With this approach it is possible to combine quantitative perfusion PET with coronary anatomy derived from CT angiography. Our first experiences indicate that manual image fusion with our tool is reproducible and that visualisation of the combined datasets is achieved within short time. (orig.)

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

    Science.gov (United States)

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

    2016-02-01

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

  7. High speed perfusion imaging based on laser speckle fluctuations

    NARCIS (Netherlands)

    Draijer, Matthijs Johannes

    2010-01-01

    Noninvasive methods to visualize blood flow in tissue are important in the clinical environment. Most methods use dynamic speckles to measure the level of perfusion. The most well-known techniques based on these speckle patterns are laser Doppler perfusion imaging (LDPI) and laser speckle contrast a

  8. Perfusion MR imaging for differentiation of benign and malignant meningiomas

    NARCIS (Netherlands)

    Zhang, Hao; Rodiger, Lars A.; Shen, Tianzhen; Miao, Jingtao; Oudkerk, Matthijs

    2008-01-01

    Introduction Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. Methods A total of 33 patients with preoperative meningiomas (25 benign and

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-01-15

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

  10. CT myocardial perfusion imaging: current status and future directions.

    Science.gov (United States)

    Williams, M C; Newby, D E

    2016-08-01

    Computed tomography (CT) imaging of the heart has advanced rapidly, and it is now possible to perform a comprehensive assessment at a low radiation dose. CT myocardial perfusion imaging can provide additive information to CT coronary angiography, and is particularly useful in patients with heavily calcified coronary arteries or coronary artery stents. A number of protocols are now available for CT myocardial perfusion including static, dynamic, and dual-energy techniques. This review will discuss the current status of CT myocardial perfusion imaging, its clinical application, and future directions for this technology.

  11. Physiological Background of Differences in Quantitative Diffusion-Weighted Magnetic Resonance Imaging Between Acute Malignant and Benign Vertebral Body Fractures: Correlation of Apparent Diffusion Coefficient With Quantitative Perfusion Magnetic Resonance Imaging Using the 2-Compartment Exchange Model.

    Science.gov (United States)

    Geith, Tobias; Biffar, Andreas; Schmidt, Gerwin; Sourbron, Steven; Dietrich, Olaf; Reiser, Maximilian; Baur-Melnyk, Andrea

    2015-01-01

    To test the hypothesis that apparent diffusion coefficient (ADC) in vertebral bone marrow of benign and malignant fractures is related to the volume of the interstitial space, determined with dynamic contrast-enhanced (DCE) magnetic resonance imaging. Patients with acute benign (n = 24) and malignant (n = 19) vertebral body fractures were examined at 1.5 T. A diffusion-weighted single-shot turbo-spin-echo sequence (b = 100 to 600 s/mm) and DCE turbo-FLASH sequence were evaluated. Regions of interest were manually selected for each fracture. Apparent diffusion coefficient was determined with a monoexponential decay model. The DCE magnetic resonance imaging concentration-time curves were analyzed using a 2-compartment tracer-kinetic model. Apparent diffusion coefficient showed a significant positive correlation with interstitial volume in the whole study population (Pearson r = 0.66, P correlation between ADC and the permeability-surface area product could be observed when analyzing the whole study population (Spearman rs = 0.40, P = 0.008), but not when separately examining the subgroups. Plasma flow showed a significant correlation with ADC in benign fractures (Pearson r = 0.23, P = 0.03). Plasma volume did not show significant correlations with ADC. The results support the hypothesis that the ADC of a lesion is inversely correlated to its cellularity. This explains previous observations that ADC is reduced in more malignant lesions.

  12. Non-negative constraint for image-based breathing gating in ultrasound hepatic perfusion data

    Science.gov (United States)

    Wu, Kaizhi; Ding, Mingyue; Chen, Xi; Deng, Wenjie; Zhang, Zhijun

    2015-12-01

    Images acquired during free breathing using contrast enhanced ultrasound hepatic perfusion imaging exhibits a periodic motion pattern. It needs to be compensated for if a further accurate quantification of the hepatic perfusion analysis is to be executed. To reduce the impact of respiratory motion, image-based breathing gating algorithm was used to compensate the respiratory motion in contrast enhanced ultrasound. The algorithm contains three steps of which respiratory kinetics extracted, image subsequences determined and image subsequences registered. The basic performance of the algorithm was to extract the respiratory kinetics of the ultrasound hepatic perfusion image sequences accurately. In this paper, we treated the kinetics extracted model as a non-negative matrix factorization (NMF) problem. We extracted the respiratory kinetics of the ultrasound hepatic perfusion image sequences by non-negative matrix factorization (NMF). The technique involves using the NMF objective function to accurately extract respiratory kinetics. It was tested on simulative phantom and used to analyze 6 liver CEUS hepatic perfusion image sequences. The experimental results show the effectiveness of our proposed method in quantitative and qualitative.

  13. 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

  14. Myocardial CT perfusion imaging and SPECT for the diagnosis of coronary artery disease

    DEFF Research Database (Denmark)

    George, Richard T; Mehra, Vishal C; Chen, Marcus Y

    2014-01-01

    ). Sensitivity and specificity were calculated with use of prespecified cutoffs. The reference standard was a stenosis of at least 50% at coronary angiography as determined with quantitative methods. RESULTS: CAD was diagnosed in 229 of the 381 patients (60%). The per-patient sensitivity and specificity......PURPOSE: To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography...... or pharmacologic stress SPECT before and within 60 days of coronary angiography. Images from CT perfusion imaging, SPECT, and coronary angiography were interpreted at blinded, independent core laboratories. The primary diagnostic parameter was the area under the receiver operating characteristic curve (Az...

  15. C-arm cone beam CT perfusion imaging in the angiographic suite: a comparison with MDCT perfusion imaging

    Science.gov (United States)

    Niu, Kai; Yang, Pengfei; Wu, Yijing; Struffert, Tobias; Doerfler, Arnd; Schafer, Sebastian; Royalty, Kevin; Strother, Charles; Chen, Guang-Hong

    2015-01-01

    Purpose and background Perfusion imaging in the angiography suite may provide a way to reduce time from stroke onset to endovascular revascularization of patients with a large vessel occlusion. Our purpose was to compare CBCTP with MDCTP. Materials and Methods Data from seven subjects with both MDCTP and CBCTP were retrospectively processed and analyzed. Two algorithms were used to enhance temporal resolution, temporal sampling density and reduce noise of CBCT data before generating perfusion maps. Two readers performed qualitative image quality evaluation on maps using a 5-point scale. ROIs indicating CBF/CBV abnormalities were drawn. Quantitative analyses were performed using the Sørensen–Dice coefficients to quantify the similarity of abnormalities. A non-inferiority hypothesis was tested to compare CBCTP against CBCTP. Results Averaged image quality score for MDCTP and CBCTP images was 2.4 and 2.3 respectively. Averaged confidence scores in diagnosis were both 1.4 for MDCT and CBCT; averaged confidence scores on presence of a CBV/CBF mismatch was 1.7 (κ = 0.50) and 1.5 (κ = 0.64). For MDCTP and CBCTP maps the average score of confidence in making treatment decision was 1.4 (κ = 0.79) and 1.3 (κ = 0.90). Area under visual grading characteristic (AVGC) for the above four qualitative quality score showed an average AVGC of 0.50 with 95% confidence level cover centered at the mean for both readers. Sørensen–Dice coefficient for CBF maps is 0.81 and for CBV maps is 0.55. Conclusions After post-processing methods were applied to enhance image quality for CBCTP maps, the CBCTP maps were not inferior to those generated from MDCTP. PMID:26892987

  16. A laser speckle imaging technique for measuring tissue perfusion.

    Science.gov (United States)

    Forrester, Kevin R; Tulip, J; Leonard, C; Stewart, C; Bray, Robert C

    2004-11-01

    Laser Doppler imaging (LDI) has become a standard method for optical measurement of tissue perfusion, but is limited by low resolution and long measurement times. We have developed an analysis technique based on a laser speckle imaging method that generates rapid, high-resolution perfusion images. We have called it laser speckle perfusion imaging (LSPI). This paper investigates LSPI output and compares it to LDI using blood flow models designed to simulate human skin at various levels of pigmentation. Results show that LSPI parameters can be chosen such that the instrumentation exhibits a similar response to changes in red blood cell concentration (0.1%-5%, 200 microL/min) and velocity (0-800 microL/min, 1% concentration) and, given its higher resolution and quicker response time, could provide a significant advantage over LDI for some applications. Differences were observed in the LDI and LSPI response to tissue optical properties. LDI perfusion values increased with increasing tissue absorption, while LSPI perfusion values showed a slight decrease. This dependence is predictable, owing to the perfusion algorithms specific to each instrument, and, if properly compensated for, should not influence each instrument's ability to measure relative changes in tissue perfusion.

  17. Improved perfusion quantification in FAIR imaging by offset correction

    DEFF Research Database (Denmark)

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

    2001-01-01

    Perfusion quantification using pulsed arterial spin labeling has been shown to be sensitive to the RF pulse slice profiles. Therefore, in Flow-sensitive Alternating-Inversion Recovery (FAIR) imaging the slice selective (ss) inversion slab is usually three to four times thicker than the imaging...... slice. However, this reduces perfusion sensitivity due to the increased transit delay of the incoming blood with unperturbed spins. In the present article, the dependence of the magnetization on the RF pulse slice profiles is inspected both theoretically and experimentally. A perfusion quantification...

  18. Adenosine stress protocols for myocardial perfusion imaging

    Directory of Open Access Journals (Sweden)

    Baškot Branislav

    2008-01-01

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

  19. Performance comparison between static and dynamic cardiac CT on perfusion quantitation and patient classification tasks

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2015-03-01

    Cardiac CT acquisitions for perfusion assessment can be performed in a dynamic or static mode. In this simulation study, we evaluate the relative classification and quantification performance of these modes for assessing myocardial blood flow (MBF). In the dynamic method, a series of low dose cardiac CT acquisitions yields data on contrast bolus dynamics over time; these data are fit with a model to give a quantitative MBF estimate. In the static method, a single CT acquisition is obtained, and the relative CT numbers in the myocardium are used to infer perfusion states. The static method does not directly yield a quantitative estimate of MBF, but these estimates can be roughly approximated by introducing assumed linear relationships between CT number and MBF, consistent with the ways such images are typically visually interpreted. Data obtained by either method may be used for a variety of clinical tasks, including 1) stratifying patients into differing categories of ischemia and 2) using the quantitative MBF estimate directly to evaluate ischemic disease severity. Through simulations, we evaluate the performance on each of these tasks. The dynamic method has very low bias in MBF estimates, making it particularly suitable for quantitative estimation. At matched radiation dose levels, ROC analysis demonstrated that the static method, with its high bias but generally lower variance, has superior performance in stratifying patients, especially for larger patients.

  20. Diffusion and Perfusion Magnetic Resonance Imaging:Fundamentals and Advances

    CERN Document Server

    Assili, Sanam

    2016-01-01

    Over the past few decades, magnetic resonance imaging has been utilized as a powerful imaging modality to evaluate the structure and function of various organs in the human body,such as the brain. Additionally, diffusion and perfusion MR imaging have been increasingly used in neurovascular clinical applications. In diffusion-weighted magnetic resonance imaging, the mobility of water molecules is explored in order to obtain information about the microscopic behavior of the tissues. In contrast, perfusion weighted imaging uses tracers to exploit hemodynamic status, which enables researchers and clinicians to consider this imaging modality as an early biomarker of certain brain diseases. In this review, the fundamentals of physics for diffusion and perfusion MR imaging both of which are highly sensitive to microenvironmental alterations at the cellular level as well as their application in the treatment of aging, Alzheimer's disease, brain tumors and cerebral ischemic injury were discussed.

  1. Noise spatial nonuniformity and the impact of statistical image reconstruction in CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lauzier, Pascal Theriault; Tang Jie; Speidel, Michael A.; Chen Guanghong [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705-2275 (United States); Department of Medical Physics and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705-2275 (United States)

    2012-07-15

    Purpose: To achieve high temporal resolution in CT myocardial perfusion imaging (MPI), images are often reconstructed using filtered backprojection (FBP) algorithms from data acquired within a short-scan angular range. However, the variation in the central angle from one time frame to the next in gated short scans has been shown to create detrimental partial scan artifacts when performing quantitative MPI measurements. This study has two main purposes. (1) To demonstrate the existence of a distinct detrimental effect in short-scan FBP, i.e., the introduction of a nonuniform spatial image noise distribution; this nonuniformity can lead to unexpectedly high image noise and streaking artifacts, which may affect CT MPI quantification. (2) To demonstrate that statistical image reconstruction (SIR) algorithms can be a potential solution to address the nonuniform spatial noise distribution problem and can also lead to radiation dose reduction in the context of CT MPI. Methods: Projection datasets from a numerically simulated perfusion phantom and an in vivo animal myocardial perfusion CT scan were used in this study. In the numerical phantom, multiple realizations of Poisson noise were added to projection data at each time frame to investigate the spatial distribution of noise. Images from all datasets were reconstructed using both FBP and SIR reconstruction algorithms. To quantify the spatial distribution of noise, the mean and standard deviation were measured in several regions of interest (ROIs) and analyzed across time frames. In the in vivo study, two low-dose scans at tube currents of 25 and 50 mA were reconstructed using FBP and SIR. Quantitative perfusion metrics, namely, the normalized upslope (NUS), myocardial blood volume (MBV), and first moment transit time (FMT), were measured for two ROIs and compared to reference values obtained from a high-dose scan performed at 500 mA. Results: Images reconstructed using FBP showed a highly nonuniform spatial distribution

  2. Quantitative dual energy CT measurements in rabbit VX2 liver tumors: Comparison to perfusion CT measurements and histopathological findings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long Jiang, E-mail: kevinzhanglongjiang@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Wu, Shengyong, E-mail: cjr.wushengyong@vip.163.com [Institute of Tianjin Medical Imaging, Tianjin 300192 (China); Wang, Mei, E-mail: 281406196@qq.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Lu, Li, E-mail: xuzhoululi@163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Chen, Bo, E-mail: chenbo1985@yahoo.com.cn [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China); Jin, Lixin, E-mail: lixin.jin@siemens.com [Siemens Healthcare, MR Collaboration NE Asia, Shanghai (China); Wang, Jiandong, E-mail: jdwang1216@163.com [Department of Pathology, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 200012 (China); Larson, Andrew C., E-mail: a-larson@northwestern.edu [Department of Radiology, Northwestern University, Chicago, IL (United States); Lu, Guang Ming, E-mail: cjr.luguangming@vip.163.com [Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, 305 Zhongshan East Road, Xuanwu District, Nangjing, Jiangsu Province 210002 (China)

    2012-08-15

    Purpose: To evaluate the correlation between quantitative dual energy CT and perfusion CT measurements in rabbit VX2 liver tumors. Materials and methods: This study was approved by the institutional animal care and use committee at our institution. Nine rabbits with VX2 liver tumors underwent contrast-enhanced dual energy CT and perfusion CT. CT attenuation for the tumors and normal liver parenchyma and tumor-to-liver ratio were obtained at the 140 kVp, 80 kVp, average weighted images and dual energy CT iodine maps. Quantitative parameters for the viable tumor and adjacent liver were measured with perfusion CT. The correlation between the enhancement values of the tumor in iodine maps and perfusion CT parameters of each tumor was analyzed. Radiation dose from dual energy CT and perfusion CT was measured. Results: Enhancement values for the tumor were higher than that for normal liver parenchyma at the hepatic arterial phase (P < 0.05). The highest tumor-to-liver ratio was obtained in hepatic arterial phase iodine map. Hepatic blood flow of the tumor was higher than that for adjacent liver (P < 0.05). Enhancement values of hepatic tumors in the iodine maps positively correlated with permeability of capillary vessel surface (r = 0.913, P < 0.001), hepatic blood flow (r = 0.512, P = 0.010), and hepatic blood volume (r = 0.464, P = 0.022) at the hepatic arterial phases. The effective radiation dose from perfusion CT was higher than that from DECT (P < 0.001). Conclusions: The enhancement values for viable tumor tissues measured in iodine maps were well correlated to perfusion CT measurements in rabbit VX2 liver tumors. Compared with perfusion CT, dual energy CT of the liver required a lower radiation dose.

  3. Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

    2016-08-15

    In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

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

    Science.gov (United States)

    Altinok, Deniz; Agarwal, Ajay; Ascadi, Gyula; Luat, Aimee; Tapos, Daniela

    2010-12-01

    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.

  5. 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.)

  6. Lesion area detection using source image correlation coefficient for CT perfusion imaging.

    Science.gov (United States)

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

    2013-09-01

    Computer tomography (CT) perfusion imaging is widely used to calculate brain hemodynamic quantities such as cerebral blood flow, cerebral blood volume, and mean transit time that aid the diagnosis of acute stroke. Since perfusion source images contain more information than hemodynamic maps, good utilization of the source images can lead to better understanding than the hemodynamic maps alone. Correlation-coefficient tests are used in our approach to measure the similarity between healthy tissue time-concentration curves and unknown curves. This information is then used to differentiate penumbra and dead tissues from healthy tissues. The goal of the segmentation is to fully utilize information in the perfusion source images. Our method directly identifies suspected abnormal areas from perfusion source images and then delivers a suggested segmentation of healthy, penumbra, and dead tissue. This approach is designed to handle CT perfusion images, but it can also be used to detect lesion areas in magnetic resonance perfusion images.

  7. 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.

  8. 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.

  9. Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging

    Science.gov (United States)

    Martin, Alastair J.; Alexander, Matthew D.; McCoy, David B.; Cooke, Daniel L.; Lillaney, Prasheel; Moftakhar, Parham; Amans, Matthew R.; Settecase, Fabio; Nicholson, Andrew; Dowd, Christopher F.; Halbach, Van V.; Higashida, Randall T.; McDermott, Michael W.; Saloner, David; Hetts, Steven W.

    2016-01-01

    Background and Purpose To evaluate the ability of IA MR perfusion to characterize meningioma blood supply. Methods Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA) and intravenous (IV) T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA) dural, internal carotid artery (ICA) dural, or pial. MR perfusion data regions of interest (ROIs) were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT). Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling. Results 18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11), ICA dural (n = 4), or pial (n = 3). FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion. PMID:27802268

  10. Parallel imaging for first-pass myocardial perfusion.

    Science.gov (United States)

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

    2007-06-01

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

  11. 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.)

  12. Quantitative Hyperspectral Reflectance Imaging

    Directory of Open Access Journals (Sweden)

    Ted A.G. Steemers

    2008-09-01

    Full Text Available Hyperspectral imaging is a non-destructive optical analysis technique that can for instance be used to obtain information from cultural heritage objects unavailable with conventional colour or multi-spectral photography. This technique can be used to distinguish and recognize materials, to enhance the visibility of faint or obscured features, to detect signs of degradation and study the effect of environmental conditions on the object. We describe the basic concept, working principles, construction and performance of a laboratory instrument specifically developed for the analysis of historical documents. The instrument measures calibrated spectral reflectance images at 70 wavelengths ranging from 365 to 1100 nm (near-ultraviolet, visible and near-infrared. By using a wavelength tunable narrow-bandwidth light-source, the light energy used to illuminate the measured object is minimal, so that any light-induced degradation can be excluded. Basic analysis of the hyperspectral data includes a qualitative comparison of the spectral images and the extraction of quantitative data such as mean spectral reflectance curves and statistical information from user-defined regions-of-interest. More sophisticated mathematical feature extraction and classification techniques can be used to map areas on the document, where different types of ink had been applied or where one ink shows various degrees of degradation. The developed quantitative hyperspectral imager is currently in use by the Nationaal Archief (National Archives of The Netherlands to study degradation effects of artificial samples and original documents, exposed in their permanent exhibition area or stored in their deposit rooms.

  13. Ventilation perfusion radionuclide imaging in cryptogenic fibrosing alveolitis

    Energy Technology Data Exchange (ETDEWEB)

    Bourke, S.J.; Hawkins, T.; Keavey, P.M.; Gascoigne, A.D.; Corris, P.A. (Freeman Hospital, Newcastle upon Tyne (United Kingdom))

    1993-06-01

    There is increasing interest in ventilation perfusion (V/Q) imaging in cryptogenic fibrosing alveolitis because of the data these scans provide on the dynamic V/Q relationships in such patients undergoing single lung transplantation. We analysed the V/Q scans of 45 consecutive patients with advanced cryptogenic fibrosing alveolitis being considered for single lung transplantation. Scans were classified according to the presence, severity and degree of matching of defects in ventilation and perfusion images and the results were compared with the data obtained from lung function tests. Ventilation images showed defects in 13 (29%) and ''washout delay'' in 15 (33%) patients; 10 (22%) patients had asymmetric distribution of ventilation with one lung receiving >60% of total ventilation. Perfusion images showed normal perfusion in 8 (18%), mild defects in 18 (40%) and major defects in 19 (42%) patients. The distribution of perfusion between lungs was significantly asymmetric in 20 (45%) patients. V/Q images were matched in 15 (33%), mildly mismatched in 15 (33%) and severely mismatched in 15 (33%) patients, but the degree of V/Q mismatch did not show a relationship to KCO, PaO[sub 2] or A-aO[sub 2] gradient. The appearances were atypical of pulmonary embolism in eight patients. (Author).

  14. Perfusion imaging with computed tomography: brain and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Miles, K.A. [Div. of Clinical and Lab. Investigation, Brighton and Sussex Medical School, Univ. of Sussex, Falmer, Brighton (United Kingdom)

    2006-01-10

    The availability of rapid imaging with multidetector CT systems and commercial analysis software has made perfusion imaging with CT an everyday technique, not only for the brain but also for other body organs. Perfusion imaging is usually performed as an adjunct to a conventional CT examination and is therefore particularly appropriate when a conventional CT is part of routine clinical protocols. The derived values are reproducible and have been validated against a range of reference techniques. Within neuroradiology, perfusion CT has attracted interest in the assessment of acute stroke but can also be used to assess secondary injury in head trauma and as an adjunct to CT angiography to evaluate cerebral spasm in subarachnoid haemorrhage. Within oncology, perfusion CT provides an imaging correlate for tumour vascularity that can be used to discriminate benign and malignant lesions, as an indicator of tumour aggressiveness, to reveal occult tumour and improve the delineation of tumours during radiotherapy planning, and as a functional assessment of tumour response to therapy. By exploiting the ability of CT systems to quantify contrast enhancement. CT perfusion imaging uses contrast media to assess vascular physiology and so improve diagnosis, prognosis, treatment selection and therapy monitoring. (orig.)

  15. Improved perfusion quantification in FAIR imaging by offset correction

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  16. Multislice CT brain image registration for perfusion studies

    Science.gov (United States)

    Lin, Zhong Min; Pohlman, Scott; Chandra, Shalabh

    2002-04-01

    During the last several years perfusion CT techniques have been developed as an effective technique for clinically evaluating cerebral hemodynamics. Perfusion CT techniques are capable of measurings functional parameters such as tissue perfusion, blood flow, blood volume, and mean transit time and are commonly used to evaluate stroke patients. However, the quality of functional images of the brain frequently suffers from patient head motion. Because the time window for an effective treatment of stroke patient is narrow, a fast motion correction is required. The purpose of the paper is to present a fast and accurate registration technique for motion correction of multi-slice CT and to demonstrate the effects of the registration on perfusion calculation.

  17. Quantitative myocardial perfusion measurement using CT perfusion: a validation study in a porcine model of reperfused acute myocardial infarction.

    Science.gov (United States)

    So, Aaron; Hsieh, Jiang; Li, Jian-Ying; Hadway, Jennifer; Kong, Hua-Fu; Lee, Ting-Yim

    2012-06-01

    We validated a CT perfusion technique with beam hardening (BH) correction for quantitative measurement of myocardial blood flow (MBF). Acute myocardial infarction (AMI) was created in four pigs by occluding the distal LAD for 1 h followed by reperfusion. MBF was measured from dynamic contrast enhanced CT (DCE-CT) scanning of the heart, with correction of cardiac motion and BH, before ischemic insult and on day 7, 10 and 14 post. On day 14 post, radiolabeled microspheres were injected to measure MBF and the results were compared with those measured by CT perfusion. Excised hearts were stained with 2,3,5-triphenyltetrazolium chloride (TTC) to determine the relationship between MBF measured by CT Perfusion and myocardial viability. MBF measured by CT perfusion was strongly correlated with that by microspheres over a wide range of MBF values (R = 0.81, from 25 to 225 ml min(-1) 100 g(-1)). While MBF in the LAD territory decreased significantly from 98.4 ± 2.5 ml min(-1) 100 g(-1) at baseline to 32.2 ± 9.1 ml min(-1) 100 g(-1), P 0.05). TTC staining confirmed incomplete infarction in the LAD territory and no infarction in the LCx territory. Microvascular obstruction in infarcted tissue resulted in no-reflow and hence persistently low MBF in the reperfused LAD territory which contained a mixture of viable and non-viable tissue. CT perfusion measurement of MBF was accurate and correlated well with histology and microspheres measurements.

  18. Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hwanjeong; Choi, Sehun; Han, Yeonhee [Research Institute of Chonbuk National Univ. Medical School and Hospitial, Jeonju (Korea, Republic of); Lee, Dong Soo; Lee, Hoyoung; Chung, Junekey [Seoul National Univ., Seoul (Korea, Republic of)

    2013-09-15

    This study aimed at identifying the predictive parameters on quantitative gated myocardial perfusion single-photon emission computed tomography (QG-SPECT) in diabetic patients with normal perfusion but impaired function. Methods Among the 533 consecutive diabetic patients, 379 patients with normal perfusion on rest Tl-201/dipyridamole-stress Tc-{sup 99m} sestamibi Gated SPECT were enrolled. Patients were grouped into those with normal post-stress left ventricular function (Group I) and those with impaired function (EF <50 or impaired regional wall motion, Group II). We investigated cardiac events and cause of death by chart review and telephone interview. Survival analysis and Cox proportional hazard model analysis were performed. Between the Group I and II, cardiac events as well as chest pain symptoms, smoking, diabetic complications were significantly different (P<0.05). On survival analysis, event free survival rate in Group II was significantly lower than in Group I (P=0.016). In univariate Cox proportional hazard analysis on overall cardiac event, Group (II over I), diabetic nephropathy, summed motion score (SMS), summed systolic thickening score (STS), numbers of abnormal segmental wall motion and systolic thickening predicted more cardiac events (P<0.05). Multivariate analysis showed that STS was the only independent predictor cardiac event. The functional parameter, especially summed systolic thickening score on QG-SPECT had prognostic values, despite normal perfusion, in predicting cardiac events in diabetic patients, and QG-SPECT provides clinically useful risk stratification in diabetic patients with normal perfusion.

  19. Perfusion and metabolism imaging studies in Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per

    2012-01-01

    analysis employed. The present review gives a comprehensive summary of the perfusion and metabolism literature in the field of PD research, including quantitative PET studies, normalized PET and SPECT studies, autoradiography studies in animal models of PD, and simulation studies of PD data...

  20. A relative quantitative assessment of myocardial perfusion by first-pass technique: animal study

    Science.gov (United States)

    Chen, Jun; Zhang, Zhang; Yu, Xuefang; Zhou, Kenneth J.

    2015-03-01

    The purpose of this study is to quantitatively assess the myocardial perfusion by first-pass technique in swine model. Numerous techniques based on the analysis of Computed Tomography (CT) Hounsfield Unit (HU) density have emerged. Although these methods proposed to be able to assess haemodynamically significant coronary artery stenosis, their limitations are noticed. There are still needs to develop some new techniques. Experiments were performed upon five (5) closed-chest swine. Balloon catheters were placed into the coronary artery to simulate different degrees of luminal stenosis. Myocardial Blood Flow (MBF) was measured using color microsphere technique. Fractional Flow Reserve (FFR) was measured using pressure wire. CT examinations were performed twice during First-pass phase under adenosine-stress condition. CT HU Density (HUDCT) and CT HU Density Ratio (HUDRCT) were calculated using the acquired CT images. Our study presents that HUDRCT shows a good (y=0.07245+0.09963x, r2=0.898) correlation with MBF and FFR. In receiver operating characteristic (ROC) curve analyses, HUDRCT provides excellent diagnostic performance for the detection of significant ischemia during adenosine-stress as defined by FFR indicated by the value of Area Under the Curve (AUC) of 0.927. HUDRCT has the potential to be developed as a useful indicator of quantitative assessment of myocardial perfusion.

  1. Repeated quantitative perfusion and contrast permeability measurement in the MRI examination of a CNS tumor

    Energy Technology Data Exchange (ETDEWEB)

    Vonken, E.P.A.; Osch, M.J.P. van; Willems, P.W.A.; Zwan, A. van der; Bakker, C.J.G.; Viergever, M.A.; Mali, W.P.T.M. [University Hospital Utrecht (Netherlands)

    2000-09-01

    This study reports on the results of quantitative MRI perfusion and contrast permeability measurement on two occasions in one patient. The measurements were separated 81 days in time. The tumor grew considerably in this period, but no change was found with respect to perfusion and contrast permeability. Non-involved white matter values were reproduced to demonstrate repeatability. The presented approach to dynamic susceptibility contrast MRI allows fast and repeatable quantitative assessment of perfusion and is easily integrated in a conventional brain tumor protocol. (orig.)

  2. Clinical use of quantitative cardiac perfusion PET: rationale, modalities and possible indications. Position paper of the Cardiovascular Committee of the European Association of Nuclear Medicine (EANM).

    Science.gov (United States)

    Sciagrà, Roberto; Passeri, Alessandro; Bucerius, Jan; Verberne, Hein J; Slart, Riemer H J A; Lindner, Oliver; Gimelli, Alessia; Hyafil, Fabien; Agostini, Denis; Übleis, Christopher; Hacker, Marcus

    2016-07-01

    Until recently, PET was regarded as a luxurious way of performing myocardial perfusion scintigraphy, with excellent image quality and diagnostic capabilities that hardly justified the additional cost and procedural effort. Quantitative perfusion PET was considered a major improvement over standard qualitative imaging, because it allows the measurement of parameters not otherwise available, but for many years its use was confined to academic and research settings. In recent years, however, several factors have contributed to the renewal of interest in quantitative perfusion PET, which has become a much more readily accessible technique due to progress in hardware and the availability of dedicated and user-friendly platforms and programs. In spite of this evolution and of the growing evidence that quantitative perfusion PET can play a role in the clinical setting, there are not yet clear indications for its clinical use. Therefore, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, decided to examine the current literature on quantitative perfusion PET to (1) evaluate the rationale for its clinical use, (2) identify the main methodological requirements, (3) identify the remaining technical difficulties, (4) define the most reliable interpretation criteria, and finally (5) tentatively delineate currently acceptable and possibly appropriate clinical indications. The present position paper must be considered as a starting point aiming to promote a wider use of quantitative perfusion PET and to encourage the conception and execution of the studies needed to definitely establish its role in clinical practice.

  3. Quantitative luminescence imaging system

    Science.gov (United States)

    Batishko, C. R.; Stahl, K. A.; Fecht, B. A.

    The goal of the Measurement of Chemiluminescence project is to develop and deliver a suite of imaging radiometric instruments for measuring spatial distributions of chemiluminescence. Envisioned deliverables include instruments working at the microscopic, macroscopic, and life-sized scales. Both laboratory and field portable instruments are envisioned. The project also includes development of phantoms as enclosures for the diazoluminomelanin (DALM) chemiluminescent chemistry. A suite of either phantoms in a variety of typical poses, or phantoms that could be adjusted to a variety of poses, is envisioned. These are to include small mammals (rats), mid-sized mammals (monkeys), and human body parts. A complete human phantom that can be posed is a long-term goal of the development. Taken together, the chemistry and instrumentation provide a means for imaging rf dosimetry based on chemiluminescence induced by the heat resulting from rf energy absorption. The first delivered instrument, the Quantitative Luminescence Imaging System (QLIS), resulted in a patent, and an R&D Magazine 1991 R&D 100 award, recognizing it as one of the 100 most significant technological developments of 1991. The current status of the project is that three systems have been delivered, several related studies have been conducted, two preliminary human hand phantoms have been delivered, system upgrades have been implemented, and calibrations have been maintained. Current development includes sensitivity improvements to the microscope-based system; extension of the large-scale (potentially life-sized targets) system to field portable applications; extension of the 2-D large-scale system to 3-D measurement; imminent delivery of a more refined human hand phantom and a rat phantom; rf, thermal and imaging subsystem integration; and continued calibration and upgrade support.

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

    Science.gov (United States)

    Gunn, Jason; Tichauer, Kenneth; Moodie, Karen; Kane, Susan; Hoopes, Jack; Stewart, Errol E.; Hadway, Jennifer; Lee, Ting-Yim; Pereira, Stephen P.; Pogue, Brian W.

    2013-03-01

    The goal of this work was to develop and validate a pancreas tumor animal model to investigate the relationship between photodynamic therapy (PDT) effectiveness and photosensitizer drug delivery. More specifically, this work lays the foundation for investigating the utility of dynamic contrast enhanced blood perfusion imaging to be used to inform subsequent PDT. A VX2 carcinoma rabbit cell line was grown in the tail of the pancreas of three New Zealand White rabbits and approximately 3-4 weeks after implantation the rabbits were imaged on a CT scanner using a contrast enhanced perfusion protocol, providing parametric maps of blood flow, blood volume, mean transit time, and vascular permeability surface area product.

  5. 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.)

  6. 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.)

  7. 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.)

  8. QUANTITATIVE ASSESSMENT OF MYOCARDIAL PERFUSION DEFECTS WITH REAL-TIME THREE-DIMENSIONAL MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    Lei Zhuang; Ming-xing Xie; Wei-juan Wang; Xiang-xin Yang; Tao Liu

    2006-01-01

    Objective To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3 DE).Methods RT3DE was performed in 21 open-chest mongrel dogs undergoing acute ligation of the left anterior descending artery (LAD,n=14) or distal branch of the left circumflex artery (LCX,n=7).A perfluorocarbon microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with Philips Sonos7500 ultrasound system. Evans blue dye was injected into the occluded coronary artery for subsequent anatomic identification of underperfused myocardium. In vitro anatomic measurement of myocardial mass after removal of the animal's heart was regarded as the control. Blinded off-line calculation of left ventricular mass and perfusion defect mass from RT3DE images were performed using an interactive aided-manual tracing technique.Results Total left ventricular (LV) myocardial mass ranged from 38. 9 to78.5 (mean±SD: 60.0±10.1)g. The mass of perfusion defect ranged from 0 to 21.4 (mean±SD: 12.0±5.0) g or 0 to 27% of total LV mass (mean±SD: 19%±6%). The RT3DE estimation of total LV mass (mean±SD: 59.8±9.9 g) strongly correlated with the anatomic measurement (r=0.98; y=2.01+0.96x). The CE-RT3DE calculation of the mass of underperfused myocardium (mean±SD: 12.3±5.3 g) also strongly correlated with the anatomic measurement (r=0.96; y=0.10+1.04x) and when expressed as percentage of total LV mass (r=0.95; y=-0.20+1.04x).Conclusions RT3DE with myocardial contrast opacification could accurately estimate underperfused myocardial mass in dogs of acute coronary occlusion and would play an important role in quantitative assessment of myocardial perfusion defects in patients with coronary artery disease.

  9. Usefulness of CT perfusion imaging in adult moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Bo Bae; Kim, Young Joo; Song, Ha Hun; Kim, Ki Tae [College of Medicine, The Catholic University of Korea, Uijongbu (Korea, Republic of)

    2004-12-01

    The purpose of this study was to evaluate the role of perfusion CT in adult moyamoya disease. The study population consisted of 13 adult moyamoya patients (10 women and 3 men, mean age: 40.4 years) and 11 age-matched normal controls (5 men and 6 women, mean age: 43 years). We retrospectively assessed the perfusion CT scan both visually and by a quantitative regional analysis, and we assessed the relationship between the perfusion CT scan findings and the angiographic findings. The mean relative cerebral blood volume (rCBV) values in moyamoya patients were 8.0% for the MCA area, 6.4% for the PCA area, and 7.7% for the basal ganglia. The rCBV values in the patients were higher than those in the control group with statistical significance (p<0.0001). The time to peak enhancement (TTP) values of the MCA area and the basal ganglia were delayed more than those in the controls; this was statistically significant (p<0.05). Moderate correlation was found between the rCBV in the basal ganglia area and angiographic stage of the basal moyamoya vessels. Perfusion CT demonstrates a statisticaIly significant increase in rCBV in the MCA, PCA and basal ganglia areas and the TTP in the MCA and basal ganglia areas in patients with moyamoya disease. The visual brain perfusion patterns correIate with the extent and severity of the basal moyamoya vessels.

  10. Muscle perfusion and metabolic heterogeneity: insights from noninvasive imaging techniques

    DEFF Research Database (Denmark)

    Kalliokoski, Kari K; Scheede-Bergdahl, Celena; Kjaer, Michael

    2006-01-01

    Recent developments in noninvasive imaging techniques have enabled the study of local changes in perfusion and metabolism in skeletal muscle as well as patterns of heterogeneity in these variables in humans. In this review, the principles of these techniques along with some recent findings on fun...

  11. Measurement of depth of burns by laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Droog, E.J.; Droog, E.J.; Steenbergen, Wiendelt; Sjöberg, F.

    2001-01-01

    Laser Doppler perfusion imaging (LDPI), is a further development in laser Doppler flowmetry (LDF). Its advantage is that it enables assessment of microvascular blood flow in a predefined skin area rather than, as for LDF, in one place. In many ways this method seems to be more promising than LDF in

  12. Preoperative subtyping of meningiomas by perfusion MR imaging

    NARCIS (Netherlands)

    Zhang, Hao; Roediger, Lars A.; Shen, Tianzhen; Miao, Jingtao; Oudkerk, Matthijs

    2008-01-01

    Introduction This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Materials and methods Thirty-seven menin

  13. Measurement of depth of burns by laser Doppler perfusion imaging

    NARCIS (Netherlands)

    Droog, E.J.; Steenbergen, W.; Sjöberg, F.

    2001-01-01

    Laser Doppler perfusion imaging (LDPI), is a further development in laser Doppler flowmetry (LDF). Its advantage is that it enables assessment of microvascular blood flow in a predefined skin area rather than, as for LDF, in one place. In many ways this method seems to be more promising than LDF in

  14. An efficient polyenergetic SART (pSART) reconstruction algorithm for quantitative myocardial CT perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yuan, E-mail: yuan.lin@duke.edu; Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, 2424 Erwin Road, Suite 302, Durham, North Carolina 27705 (United States)

    2014-02-15

    Purpose: In quantitative myocardial CT perfusion imaging, beam hardening effect due to dense bone and high concentration iodinated contrast agent can result in visible artifacts and inaccurate CT numbers. In this paper, an efficient polyenergetic Simultaneous Algebraic Reconstruction Technique (pSART) was presented to eliminate the beam hardening artifacts and to improve the CT quantitative imaging ability. Methods: Our algorithm made threea priori assumptions: (1) the human body is composed of several base materials (e.g., fat, breast, soft tissue, bone, and iodine); (2) images can be coarsely segmented to two types of regions, i.e., nonbone regions and noniodine regions; and (3) each voxel can be decomposed into a mixture of two most suitable base materials according to its attenuation value and its corresponding region type information. Based on the above assumptions, energy-independent accumulated effective lengths of all base materials can be fast computed in the forward ray-tracing process and be used repeatedly to obtain accurate polyenergetic projections, with which a SART-based equation can correctly update each voxel in the backward projecting process to iteratively reconstruct artifact-free images. This approach effectively reduces the influence of polyenergetic x-ray sources and it further enables monoenergetic images to be reconstructed at any arbitrarily preselected target energies. A series of simulation tests were performed on a size-variable cylindrical phantom and a realistic anthropomorphic thorax phantom. In addition, a phantom experiment was also performed on a clinical CT scanner to further quantitatively validate the proposed algorithm. Results: The simulations with the cylindrical phantom and the anthropomorphic thorax phantom showed that the proposed algorithm completely eliminated beam hardening artifacts and enabled quantitative imaging across different materials, phantom sizes, and spectra, as the absolute relative errors were reduced

  15. Qualitative and semi-quantitative evaluation of myocardium perfusion with 3 T stress cardiac MRI.

    Science.gov (United States)

    Yun, Chun-Ho; Tsai, Jui-Peng; Tsai, Cheng-Ting; Mok, Greta S P; Sun, Jing-Yi; Hung, Chung-Lieh; Wu, Tung-Hsin; Huang, Wu-Ta; Yang, Fei-Shih; Lee, Jason Jeun-Shenn; Cury, Ricardo C; Fares, Anas; Nshisso, Lemba Dina; Bezerra, Hiram G

    2015-12-07

    3 T MRI has been adopted by some centers as the primary choice for assessment of myocardial perfusion over conventional 1.5 T MRI. However, there is no data published on the potential additional value of incorporating semi-quantitative data from 3 T MRI. This study sought to determine the performance of qualitative 3 T stress magnetic resonance myocardial perfusion imaging (3 T-MRMPI) and the potential incremental benefit of using a semi-quantitative perfusion technique in patients with suspected coronary artery disease (CAD). Fifty eight patients (41 men; mean age: 59 years) referred for elective diagnostic angiography underwent stress 3 T MRMPI with a 32-channel cardiac receiver coil. The MR protocol included gadolinium-enhanced stress first-pass perfusion (0.56 mg/kg, dipyridamole), rest perfusion, and delayed enhancement (DE). Visual analysis was performed in two steps. Ischemia was defined as a territory with perfusion defect at stress study but no DE or a territory with DE but additional peri-infarcted perfusion defect at stress study. Semi-quantitative analysis was calculated by using the upslope of the signal intensity-time curve during the first pass of contrast medium during dipyridamole stress and at rest. ROC analysis was used to determine the MPRI threshold that maximized sensitivity. Quantitative coronary angiography served as the reference standard with significant stenosis defined as >70 % diameter stenosis. Diagnostic performance was determined on a per-patient and per-vessel basis. Qualitative assessment had an overall sensitivity and specificity for detecting significant stenoses of 77 % and 80 %, respectively. By adding MPRI analysis, in cases with negative qualitative assessment, the overall sensitivity increased to 83 %. The impact of MPRI differed depending on the territory; with the sensitivity for detection of left circumflex (LCx) stenosis improving the most after semi-quantification analysis, (66 % versus 83 %). Pure

  16. Whole-organ CT perfusion of the pancreas: impact of iterative reconstruction on image quality, perfusion parameters and radiation dose in 256-slice CT-preliminary findings.

    Directory of Open Access Journals (Sweden)

    Qian Xie

    Full Text Available BACKGROUND: This study was performed to assess whether iterative reconstruction can reduce radiation dose while maintaining acceptable image quality, and to investigate whether perfusion parameters vary from conventional filtered back projection (FBP at the low-tube-voltage (80-kVp during whole-pancreas perfusion examination using a 256-slice CT. METHODS: 76 patients with known or suspected pancreatic mass underwent whole-pancreas perfusion by a 256-slice CT. High- and low-tube-voltage CT images were acquired. 120-kVp image data (protocol A and 80-kVp image data (protocol B were reconstructed with conventional FBP, and 80-kVp image data were reconstructed with iDose(4 (protocol C iterative reconstruction. The image noise; contrast-to-noise ratio (CNR relative to muscle for the pancreas, liver, and aorta; and radiation dose of each protocol were assessed quantitatively. Overall image quality was assessed qualitatively. Among 76 patients, 23 were eventually proven to have a normal pancreas. Perfusion parameters of normal pancreas in each protocol including blood volume, blood flow, and permeability-surface area product were measured. RESULTS: In the quantitative study, protocol C reduced image noise by 36.8% compared to protocol B (P<0.001. Protocol C yielded significantly higher CNR relative to muscle for the aorta, pancreas and liver compared to protocol B (P<0.001, and offered no significant difference compared to protocol A. In the qualitative study, protocols C and A gained similar scores and protocol B gained the lowest score for overall image quality (P<0.001. Mean effective doses were 23.37 mSv for protocol A and 10.81 mSv for protocols B and C. There were no significant differences in the normal pancreas perfusion values among three different protocols. CONCLUSION: Low-tube-voltage and iDose(4 iterative reconstruction can dramatically decrease the radiation dose with acceptable image quality during whole-pancreas CT perfusion and have no

  17. Burn imaging with a whole field laser Doppler perfusion imager based on a CMOS imaging array

    NARCIS (Netherlands)

    van Herpt, Heleen; Draijer, Matthijs; Hondebrink, Erwin; Nieuwenhuis, Marianne; Beerthuizen, Gerard; van Leeuwen, Ton; Steenbergen, Wiendelt

    2010-01-01

    Laser Doppler perfusion imaging (LDPI) has been proven to be a useful tool in predicting the burn wound outcome in an early stage. A major disadvantage of scanning beam LDPI devices is their slow scanning speed, leading to patient discomfort and imaging artifacts. We have developed the Twente Optica

  18. Burn imaging with a whole field laser Doppler perfusion imager based on a CMOS imaging array

    NARCIS (Netherlands)

    van Herpt, Heleen; Draijer, Matthijs; Hondebrink, Erwin; Nieuwenhuis, Marianne; Beerthuizen, Gerard; van Leeuwen, Ton; van Leeuwen, Ton; Steenbergen, Wiendelt

    2010-01-01

    Laser Doppler perfusion imaging (LDPI) has been proven to be a useful tool in predicting the burn wound outcome in an early stage. A major disadvantage of scanning beam LDPI devices is their slow scanning speed, leading to patient discomfort and imaging artifacts. We have developed the Twente

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

    Science.gov (United States)

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

    1998-07-01

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

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

    Science.gov (United States)

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

    2005-04-01

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

  1. Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

    Science.gov (United States)

    Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p liver tissue, but other parameters kept constant. CT perfusion imaging is able to detect decrease in blood perfusion of liver cancer post-argon-helium knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy.

  2. Laser Doppler perfusion monitoring and imaging of blood microcirculation

    Science.gov (United States)

    Nilsson, Gert E.; Wardell, Karin

    1994-07-01

    Laser Doppler perfusion monitoring is a method of assessing tissue perfusion based on measurements performed using Doppler broadening of monochromatic light scattered in moving blood cells. Ever since laser Doppler perfusion monitors became available about 15 years ago they have been used in numerous applications in both clinical and laboratory settings. The high spatial resolution has in practice manifested itself as one of the main limitations of the method. The reason for this is the difficulty in attaining reproducible values at successive measurement sites because most skin tissue possesses a substantial variation in blood flow even at adjacent measurement sites. In order to overcome this difficulty the laser Doppler perfusion imager was developed. In this camera-like device, the laser beam successively scans the tissue and the Doppler components of the backscattered light are detected by a remote photodiode. After a scanning procedure is complete, a color-coded perfusion map showing the spatial variation of skin blood flow is displayed on a monitor. The operating principle and early applications of this emerging technology are addressed in further detail.

  3. 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

    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...... slices, each having 60 sectors, provided an estimation of the severity and extent of the perfusion deficiency. Reperfusion was assessed both by noninvasive criteria and by coronary angiography (CAG). RESULTS: The Ki maps clearly delineated the infarction in all patients. Thrombolytic treatment...... 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...

  4. Motion correction for improving the accuracy of dual-energy myocardial perfusion CT imaging

    Science.gov (United States)

    Pack, Jed D.; Yin, Zhye; Xiong, Guanglei; Mittal, Priya; Dunham, Simon; Elmore, Kimberly; Edic, Peter M.; Min, James K.

    2016-03-01

    Coronary Artery Disease (CAD) is the leading cause of death globally [1]. Modern cardiac computed tomography angiography (CCTA) is highly effective at identifying and assessing coronary blockages associated with CAD. The diagnostic value of this anatomical information can be substantially increased in combination with a non-invasive, low-dose, correlative, quantitative measure of blood supply to the myocardium. While CT perfusion has shown promise of providing such indications of ischemia, artifacts due to motion, beam hardening, and other factors confound clinical findings and can limit quantitative accuracy. In this paper, we investigate the impact of applying a novel motion correction algorithm to correct for motion in the myocardium. This motion compensation algorithm (originally designed to correct for the motion of the coronary arteries in order to improve CCTA images) has been shown to provide substantial improvements in both overall image quality and diagnostic accuracy of CCTA. We have adapted this technique for application beyond the coronary arteries and present an assessment of its impact on image quality and quantitative accuracy within the context of dual-energy CT perfusion imaging. We conclude that motion correction is a promising technique that can help foster the routine clinical use of dual-energy CT perfusion. When combined, the anatomical information of CCTA and the hemodynamic information from dual-energy CT perfusion should facilitate better clinical decisions about which patients would benefit from treatments such as stent placement, drug therapy, or surgery and help other patients avoid the risks and costs associated with unnecessary, invasive, diagnostic coronary angiography procedures.

  5. High-resolution myocardial perfusion mapping in small animals in vivo by spin-labeling gradient-echo imaging.

    Science.gov (United States)

    Kober, Frank; Iltis, Isabelle; Izquierdo, Marguerite; Desrois, Martine; Ibarrola, Danielle; Cozzone, Patrick J; Bernard, Monique

    2004-01-01

    An ECG and respiration-gated spin-labeling gradient-echo imaging technique is proposed for the quantitative and completely noninvasive measurement and mapping of myocardial perfusion in small animals in vivo. In contrast to snapshot FLASH imaging, the spatial resolution of the perfusion maps is not limited by the heart rate. A significant improvement in image quality is achieved by synchronizing the inversion pulse to the respiration movements of the animals, thereby allowing for spontaneous respiration. High-resolution myocardial perfusion maps (in-plane resolution=234 x 468 microm2) demonstrating the quality of the perfusion measurement were obtained at 4.7 T in a group of seven freely breathing Wistar-Kyoto rats under isoflurane anesthesia. The mean perfusion value (group average +/- SD) was 5.5 +/- 0.7 ml g(-1)min(-1). In four animals, myocardial perfusion was mapped and measured under cardiac dobutamine stress. Perfusion increased to 11.1 +/- 1.9 ml g(-1)min(-1). The proposed method is particularly useful for the study of small rodents at high fields.

  6. Dynamic CT Perfusion Imaging for the Detection of Crossed Cerebellar Diaschisis in Acute Ischemic Stroke

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Young Wook; Kim, Seo Hyun; Lee, Ji Young; Whang, Kum; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub; Brain Reserch Group [Wonju Christian Hospital, Yonsei University Wonju University College of Medicine, Wonju (Korea, Republic of)

    2012-01-15

    Although the detection of crossed cerebellar diaschisis (CCD) by means of different imaging modalities is well described, little is known about its diagnosis by computed tomography perfusion (CTP) imaging. We investigated the detection rate of CCD by CTP imaging and the factors related to CCD on CTP images in patients with acute ischemic stroke. CT perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) obtained from 81 consecutive patients affected by an acute ischemic stroke were retrospectively reviewed. Whole-brain perfusion maps were obtained with a multichannel CT scanner using the toggling-table technique. The criteria for CCD was a unilateral supratentorial ischemic lesion and an accompanying decrease in perfusion of the contralateral cerebellar hemisphere on the basis of CTP maps by visual inspection without a set threshold. Maps were quantitatively analyzed in CCD positive cases. The criteria for CCD were fulfilled in 25 of the 81 cases (31%). Detection rates per CTP map were as follows: MTT (31%) > TTP (21%) > CBF (9%) > CBV (6%). Supratentorial ischemic volume, degree of perfusion reduction, and infratentorial asymmetry index correlated strongly (R, 0.555-0.870) and significantly (p < 0.05) with each other in CCD-positive cases. It is possible to detect CCD on all four of the CTP-based maps. Of these maps, MTT is most sensitive in detecting CCD. Our data indicate that CTP imaging is a valid tool for the diagnosis of CCD in patients affected by an acute hemispheric stroke.

  7. Unevenness of lung perfusion images and pulmonary diseases

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-07-01

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

  8. A new deconvolution approach to perfusion imaging exploiting spatial correlation

    Science.gov (United States)

    Orten, Burkay B.; Karl, W. Clem; Sahani, Dushyant V.; Pien, Homer

    2008-03-01

    The parts of the human body affected by a disease do not only undergo structural changes but also demonstrate significant physiological (functional) abnormalities. An important parameter that reveals the functional state of tissue is the flow of blood per unit tissue volume or perfusion, which can be obtained using dynamic imaging methods. One mathematical approach widely used for estimating perfusion from dynamic imaging data is based on a convolutional tissue-flow model. In these approaches, deconvolution of the observed data is necessary to obtain the important physiological parameters within a voxel. Although several alternatives have been proposed for deconvolution, all of them treat neighboring voxels independently and do not exploit the spatial correlation between voxels or the temporal correlation within a voxel over time. These simplistic approaches result in a noisy perfusion map with poorly defined region boundaries. In this paper, we propose a novel perfusion estimation method which incorporates spatial as well as temporal correlation into the deconvolution process. Performance of our method is compared to standard methods using independent voxel processing. Both simulated and real data experiments illustrate the potential of our method.

  9. Penumbra pattern assessment in acute stroke patients: comparison of quantitative and non-quantitative methods in whole brain CT perfusion.

    Directory of Open Access Journals (Sweden)

    Kolja M Thierfelder

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

  10. Perfusion imaging with non-contrast ultrasound

    Science.gov (United States)

    Tierney, Jaime E.; Dumont, Douglas M.; Byram, Brett C.

    2016-04-01

    A Doppler ultrasound clutter filter that enables estimation of low velocity blood flow could considerably improve ultrasound as a tool for clinical diagnosis and monitoring, including for the evaluation of vascular diseases and tumor perfusion. Conventional Doppler ultrasound is currently used for visualizing and estimating blood flow. However, conventional Doppler is limited by frame rate and tissue clutter caused by involuntary movement of the patient or sonographer. Spectral broadening of the clutter due to tissue motion limits ultrasound's ability to detect blood flow less than about 5mm/s at an 8MHz center frequency. We propose a clutter filtering technique that may increase the sensitivity of Doppler measurements to at least as low as 0.41mm/s. The proposed filter uses an adaptive demodulation scheme that decreases the bandwidth of the clutter. To test the performance of the adaptive demodulation method at removing sonographer hand motion, six volunteer subjects acquired data from a basic quality assurance phantom. Additionally, to test initial in vivo feasibility, an arterial occlusion reactive hyperemia study was performed to assess the efficiency of the proposed filter at preserving signals from blood velocities 2mm/s or greater. The hand motion study resulted in initial average bandwidths of 577Hz (28.5mm/s), which were decreased to 7.28Hz (0.36mm/s) at -60 dB at 3cm using our approach. The in vivo power Doppler study resulted in 15.2dB and 0.15dB dynamic ranges between the lowest and highest blood flow time points for the proposed filter and conventional 50Hz high pass filter, respectively.

  11. Prediction of postoperative loss of lung function in patients with malignant lung mass. Quantitative regional ventilation-perfusion scanning

    Energy Technology Data Exchange (ETDEWEB)

    Ryo, U.Y. (Univ. of Kentucky College of Medicine, Lexington (USA))

    1990-05-01

    The quantitative measurement of regional ventilation and perfusion distribution is simply and reliably accomplished by using routinely available radioactive gas and perfusion lung scanning agents, and a large field-of-view gamma camera with an on-line computer. The preoperative prediction of postsurgical loss in lung function can be made accurately by using the quantitative ventilation-perfusion lung scan technique. Either a regional ventilation study or perfusion study may be used for the prediction, but analysis of regional ventilation distribution appears to be a better parameter than that of perfusion distribution for the prediction of postoperative loss of FEV1. In the rare case of a patient with a marked ventilation-perfusion deficit, quantitative distribution of both ventilation and perfusion may be needed for an accurate assessment of postsurgical lung function. 18 references.

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

    Directory of Open Access Journals (Sweden)

    Kiuru Aaro

    2003-01-01

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

  13. Clinical outcomes meta-analysis: measuring subendocardial perfusion and efficacy of transmyocardial laser revascularization with nuclear imaging.

    Science.gov (United States)

    Iwanski, Jessika; Knapp, Shannon M; Avery, Ryan; Oliva, Isabel; Wong, Raymond K; Runyan, Raymond B; Khalpey, Zain

    2017-05-19

    Randomized and nonrandomized clinical trials have tried to assess whether or not TMR patients experience an increase in myocardial perfusion. However there have been inconsistencies reported in the literature due to the use of different nuclear imaging modalities to test this metric. The primary purpose of this meta-analysis was to determine whether SPECT, MUGA and PET scans demonstrate changes in myocardial perfusion between lased and non-lased subjects and whether laser type affects myocardial perfusion. The secondary purpose was to examine the overall effect of laser therapy on clinical outcomes including survival, hospital re-admission and angina reduction. Sixteen studies were included in the primary endpoint analysis after excluding all other non-imaging TMR papers. Standardized mean difference was used as the effect size for all quantitative outcomes and log odds ratio was used as the effect size for all binary outcomes. Statistically significant improvements in myocardial perfusion were observed between control and treatment groups in myocardial perfusion at 6-month follow up using PET imaging with a porcine model. However non-significant differences were observed in patients at 3 and 12 months using SPECT, PET or MUGA scans. Both CO2 and Ho:YAG laser systems demonstrated an increase in myocardial perfusion however this effect was not statistically significant. In addition both laser types displayed statistically significant decreases in patient angina at 3, 6 and 12 months but non-significant increases in survival rates and decreases in hospital re-admissions. In order to properly assess myocardial perfusion in TMR subjects, subendocardial perfusion needs to be analyzed via nuclear imaging. PET scans can provide this level of sensitivity and should be utilized in future studies to monitor and detect perfusion changes in lased and non-lased subjects.

  14. Value or waste: Perfusion imaging following radiofrequency ablation - early experience.

    Science.gov (United States)

    Thieme, Stefan F; Vahldiek, Janis L; Tummler, Katja; Poch, Franz; Gemeinhardt, Ole; Hiebl, Bernhard; Lehmann, Kai S; Hamm, B; Niehues, Stefan M

    2015-01-01

    Radiofrequency ablation (RFA) is an evolving technique in treatment of hepatic malignant tumors. By heating local tissue it leads to coagulative necrotic areas around the ablation probe. Temperature falls with increasing distance to the probe, risking incomplete necrosis at the margins of the RFA-induced lesion. Therefore, immediate non-invasive and precise detection of incomplete ablation is necessary for early enlargement of the ablation if needed. This in vivo pig study compares early experiences of immediate post-interventional computed tomography (CT) perfusion volume analysis to macroscopic and CT image evaluation in healthy pig liver. RFA was performed in vivo in healthy pig livers. Different CT perfusion algorithms (Maximum slope analysis and Patlak plot) were used to quantify three different perfusion parameters. Data points were acquired from rectangular grids. These grids were semiautomatically overlayed to macroscopic images documented after liver explantation. Each data point was visually assigned to zones defined as "inner" and "outer necrotic zone", "margin" or "vital tissue". Significant differences between necrotic zones and vital tissue are shown for equivalent blood volume (p <  0.0001), arterial flow (p <  0.01) and flow extraction product (p <  0.001). Looking at equivalent blood volume and flow extraction product, there were also significant differences (EquivBV: p <  0.0001, FE: p <  0.001) between margins, necrotic and vital areas. In a porcine model these early results could show that all of the used CT perfusion parameters allowed discrimination of necrosis from vital tissue after RFA at high levels of significance. In addition, the parameters EquivBV and FE that give an estimate of the tissue blood volume and the permeability, were able to precisely discern different zones also seen macroscopically. From this data CT perfusion analysis could be precise tool for measurement and visualization of ablated liver lesions and

  15. Serial investigation of perfusion disturbances and vasogenic oedema in hypertensive encephalopathy by diffusion and perfusion weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sundgren, P.C.; Holtaas, S. [Department of Diagnostic Radiology, University Hospital of Lund (Sweden); Edvardsson, B. [Department of Neurology, University Hospital of Lund (Sweden)

    2002-04-01

    Serial MRI including diffusion and perfusion imaging was performed in a patient with hypertensive encephalopathy. At admission, the patient was disorientated and presented with seizures and cortical blindness. Perfusion imaging showed a marked reduction in blood volume and flow, with corresponding vasogenic oedema in the occipital, posterior temporal, and, to a lesser extent, frontal lobes. The clinical symptoms disappeared rapidly following treatment, whereas the disturbed circulation pattern and vasogenic oedema resolved more slowly. A complete normalisation was seen after 1 year. (orig.)

  16. Use of intravenous dipyridamole in thallium 201 myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, F.P.; Blend, M.J.

    1987-01-01

    Thallium 201 myocardial perfusion imaging is a standard method of evaluating regional myocardial blood flow. Myocardial perfusion is best evaluated at rest and during exercise, however, alternative methods have been sought to increase coronary blood flow in patients incapable of performing adequate exercise. A promising new method is the use of intravenous dipyridamole for pharmacologic stress imaging. It has distinct advantages over traditional treadmill exercise testing. The primary advantage of combining intravenous dipyridamole and thallium 201 is for testing patients in whom exercise is impractical or contraindicated. Examples include patients taking beta blockers and those who have had myocardial infarction or have severe peripheral vascular disease. To date, this agent has been available only to clinical investigators in approved protocols. With continued success, it should be approved for general use in the near future. 33 references.

  17. Stress myocardial perfusion imaging with multidetector CT

    NARCIS (Netherlands)

    A. Rossi (Alexia); D. Merkus (Daphne); E. Klotz (Ernst); N.R.A. Mollet (Nico); P.J. de Feyter (Pim); G.P. Krestin (Gabriel)

    2014-01-01

    textabstractComputed tomographic (CT) coronary angiography is a well-established, noninvasive imaging modality for detection of coronary stenosis, but it has limited accuracy in demonstrating whether a coronary stenosis is hemodynamically significant. An additional functional test is often required

  18. Stress myocardial perfusion imaging with multidetector CT

    NARCIS (Netherlands)

    A. Rossi (Alexia); D. Merkus (Daphne); E. Klotz (Ernst); N.R.A. Mollet (Nico); P.J. de Feyter (Pim); G.P. Krestin (Gabriel)

    2014-01-01

    textabstractComputed tomographic (CT) coronary angiography is a well-established, noninvasive imaging modality for detection of coronary stenosis, but it has limited accuracy in demonstrating whether a coronary stenosis is hemodynamically significant. An additional functional test is often required

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

    Science.gov (United States)

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

    2015-09-01

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

  20. Preoperative subtyping of meningiomas by perfusion MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [University Medical Center Groningen, University of Groningen (Netherlands); Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China); Department of Radiology, University of Groningen (Netherlands); Roediger, Lars A.; Oudkerk, Matthijs [University Medical Center Groningen, University of Groningen (Netherlands); Department of Radiology, University of Groningen (Netherlands); Shen, Tianzhen [Fudan University Huashan Hospital, Department of Radiology, Shanghai (China); Miao, Jingtao [Shanghai Jiaotong University affiliated First People' s Hospital, Department of Radiology, Shanghai (China)

    2008-10-15

    This paper aims to evaluate the value of perfusion magnetic resonance (MR) imaging in the preoperative subtyping of meningiomas by analyzing the relative cerebral blood volume (rCBV) of three benign subtypes and anaplastic meningiomas separately. Thirty-seven meningiomas with peritumoral edema (15 meningothelial, ten fibrous, four angiomatous, and eight anaplastic) underwent perfusion MR imaging by using a gradient echo echo-planar sequence. The maximal rCBV (compared with contralateral normal white matter) in both tumoral parenchyma and peritumoral edema of each tumor was measured. The mean rCBVs of each two histological subtypes were compared using one-way analysis of variance and least significant difference tests. A p value less than 0.05 indicated a statistically significant difference. The mean rCBV of meningothelial, fibrous, angiomatous, and anaplastic meningiomas in tumoral parenchyma were 6.93{+-}3.75, 5.61{+-}4.03, 11.86{+-}1.93, and 5.89{+-}3.85, respectively, and in the peritumoral edema 0.87{+-}0.62, 1.38{+-}1.44, 0.87{+-}0.30, and 3.28{+-}1.39, respectively. The mean rCBV in tumoral parenchyma of angiomatous meningiomas and in the peritumoral edema of anaplastic meningiomas were statistically different (p<0.05) from the other types of meningiomas. Perfusion MR imaging can provide useful functional information on meningiomas and help in the preoperative diagnosis of some subtypes of meningiomas. (orig.)

  1. Perfusion MR imaging for differentiation of benign and malignant meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [University of Groningen, Department of Radiology, University Medical Center Groningen, Groningen (Netherlands); Shanghai Jiaotong University, Department of Radiology, First People' s Hospital, Shanghai (China); Roediger, Lars A.; Oudkerk, Matthijs [University of Groningen, Department of Radiology, University Medical Center Groningen, Groningen (Netherlands); Shen, Tianzhen [Fudan University, Department of Radiology, Huashan Hospital, Shanghai (China); Miao, Jingtao [Shanghai Jiaotong University, Department of Radiology, First People' s Hospital, Shanghai (China)

    2008-06-15

    Our purpose was to determine whether perfusion MR imaging can be used to differentiate benign and malignant meningiomas on the basis of the differences in perfusion of tumor parenchyma and/or peritumoral edema. A total of 33 patients with preoperative meningiomas (25 benign and 8 malignant) underwent conventional and dynamic susceptibility contrast perfusion MR imaging. Maximal relative cerebral blood volume (rCBV) and the corresponding relative mean time to enhance (rMTE) (relative to the contralateral normal white matter) in both tumor parenchyma and peritumoral edema were measured. The independent samples t-test was used to determine whether there was a statistically significant difference in the mean rCBV and rMTE ratios between benign and malignant meningiomas. The mean maximal rCBV values of benign and malignant meningiomas were 7.16{+-}4.08 (mean{+-}SD) and 5.89{+-}3.86, respectively, in the parenchyma, and 1.05{+-}0.96 and 3.82{+-}1.39, respectively, in the peritumoral edema. The mean rMTE values were 1.16{+-}0.24 and 1.30{+-}0.32, respectively, in the parenchyma, and 0.91{+-}0.25 and 1.24{+-}0.35, respectively, in the peritumoral edema. The differences in rCBV and rMTE values between benign and malignant meningiomas were not statistically significant (P>0.05) in the parenchyma, but both were statistically significant (P<0.05) in the peritumoral edema. Perfusion MR imaging can provide useful information on meningioma vascularity which is not available from conventional MRI. Measurement of maximal rCBV and corresponding rMTE values in the peritumoral edema is useful in the preoperative differentiation between benign and malignant meningiomas. (orig.)

  2. Endoscopic ICG perfusion imaging for flap transplants: technical development

    Science.gov (United States)

    Stepp, Herbert; Schachenmayr, Hilmar; Ehrhardt, André; Göbel, Werner; Zhorzel, Sven; Betz, Christian Stephan

    2010-02-01

    Objective: Following tumour surgery in the head and neck region, skin flap transplants are usually required to cover the resection area. The purpose of the development was to provide a simple and reliable means to assess whether the transplanted flap is sufficiently perfused. Methods: Fluorescence of intravenously injected Indocyanine green (ICG) was detected with a slightly modified 3-chip CCD camera. Appropriately coated optical filters allow for excitation of ICG with NIR light and detection of NIR ICGfluorescence with the blue channel of the camera. In addition, low intensities of white light can be transmitted to allow for simultaneous display of a remission image in the green and red channels of the camera. Further processing was performed with a LabVIEW program. Results: A satisfactory white light image (red, green and blue display (RGB)) could be calculated from the remission images recorded with the green and red channels of the camera via a look-up table. The look-up table was programmed to provide an optimized blue intensity value for each combination of red and green values. This was generated using a reference image. Implementation of image tracking and intensity measurements in regions of interest (ROIs) in the images is useful to reliably monitor perfusion kinetics of flap and adjacent normal tissue.

  3. Computed tomography perfusion imaging denoising using Gaussian process regression

    Science.gov (United States)

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

    2012-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-02-15

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

  5. Improved perfusion quantification in FAIR imaging by offset correction

    DEFF Research Database (Denmark)

    Sidaros, K; Andersen, I K; Gesmar, H;

    2001-01-01

    Perfusion quantification using pulsed arterial spin labeling has been shown to be sensitive to the RF pulse slice profiles. Therefore, in Flow-sensitive Alternating-Inversion Recovery (FAIR) imaging the slice selective (ss) inversion slab is usually three to four times thicker than the imaging sl...... model is presented that allows the use of thinner ss inversion slabs by taking into account the offset of RF slice profiles between ss and nonselective inversion slabs. This model was tested in both phantom and human studies. Magn Reson Med 46:193-197, 2001....

  6. Advanced NSCLC First Pass Perfusion at 64-slice CT: Reproducibility of Volume-based Quantitative Measurement

    Directory of Open Access Journals (Sweden)

    Jie HU

    2010-05-01

    Full Text Available Background and objective The aim of this study is to explore the reproducibility of volume-based quantitative measurement of non-small cell lung cancer (NSCLC perfusion at 64-slice CT. Methods Fourteen patients with proved advanced NSCLC were enrolled in this dynamic first pass volume-based CT perfusion (CTP study (8×5 mm collimation, and they underwent the second scan within 24 h. According to the longest diameters, those patients were classified to ≤3 cm and >3 cm groups, and each group had 7 patients. Intraclass correlation coefficient (ICC and Bland-Altman statistics were used to evaluate the reproducibility of CTP imaging. Results In both groups of advanced NSCLC, the reproducibility with BF, BV, and PS values were good (ICC >0.75 for all, but mean transit time (MTT values. For advanced NSCLC (≤3 cm, repeatability coefficient (RC values with blood flow (BF, blood volume (BV, MTT and permeability surface area product (PS values were 56%, 45%, 114%, and 78%, respectively, and the 95% change intervals of RC were -39%-53%, -29%-62%, -83%-145%, and -57%-98%, respectively. For advanced NSCLC (>3 cm, those values were 46%, 30%, 59%, and 33%, respectively, and the 95% change intervals of RC were -48%-45%, -33%-26%, -54%-64%, and -18%-48%. Conclusion There is greater reproducibility of tumor size >3 cm than that of ≤3 cm. BF and BV could be addressed for reliable clinical application in antiangiogenesis therapeutic monitoring with advanced NSCLC patients.

  7. Quantitative imaging methods in osteoporosis.

    Science.gov (United States)

    Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M Carola; Oei, Edwin H G

    2016-12-01

    Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.

  8. Score cards for standardized comparison of myocardial perfusion imaging reports

    DEFF Research Database (Denmark)

    Jensen, Julie D; Hoff, Camilla; Bouchelouche, Kirsten

    Background: When optimizing scan protocols or comparing modalities in myocardial perfusion imaging, it is necessary to compare the current method to the new method This can be achieved by a comparison based on hard numbers such as MBF, summed rest and stress scores, total perfusion deficit etc....... However, what is of importance to the patient is the total evaluation of these scores and the weight and confidence ascribed to each by the reporting physician. We suggest a standardized method summarizing the observations and the confidence of the physician in simple scores. We tested the developed score...... cards in a pilotproject using a training scenario where 3 observers with varying experience (1 month, 5 months and 3 years, respectively) scored static rest/stress Rb-82 PET scans. Method: 10 patients with known ischemic heart disease were included. Using the 17-segment AHA cardiac model, each patient...

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

    Science.gov (United States)

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

    2009-01-01

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

  10. Quantitative ultrasonic phased array imaging

    Science.gov (United States)

    Engle, Brady J.; Schmerr, Lester W., Jr.; Sedov, Alexander

    2014-02-01

    When imaging with ultrasonic phased arrays, what do we actually image? What quantitative information is contained in the image? Ad-hoc delay-and-sum methods such as the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM) fail to answer these questions. We have shown that a new quantitative approach allows the formation of flaw images by explicitly inverting the Thompson-Gray measurement model. To examine the above questions, we have set up a software simulation test bed that considers a 2-D scalar scattering problem of a cylindrical inclusion with the method of separation of variables. It is shown that in SAFT types of imaging the only part of the flaw properly imaged is the front surface specular response of the flaw. Other responses (back surface reflections, creeping waves, etc.) are improperly imaged and form artifacts in the image. In the case of TFM-like imaging the quantity being properly imaged is an angular integration of the front surface reflectivity. The other, improperly imaged responses are also averaged, leading to a reduction in some of the artifacts present. Our results have strong implications for flaw sizing and flaw characterization with delay-and-sum images.

  11. Clearing of psoriasis documented by laser Doppler perfusion imaging contrasts remaining elevation of dermal expression levels of CD31

    NARCIS (Netherlands)

    Hendriks, A.G.M.; Kerkhof, van de P.C.M.; Jonge, de C.S.; Lucas, M.; Steenbergen, W.; Seyger, M.M.B.

    2015-01-01

    Background Vascular modifications represent a key feature in psoriatic plaques. Previous research with Laser Doppler Perfusion Imaging (LDPI) revealed a remarkable heterogeneity in the cutaneous perfusion within homogenous-appearing psoriatic lesions. Insights in the relation between perfusion durin

  12. Clearing of psoriasis documented by laser Doppler perfusion imaging contrasts remaining elevation of dermal expression levels of CD31

    NARCIS (Netherlands)

    Hendriks, A.G.M.; Kerkhof, P.C.M. van de; Jonge, C.S. de; Lucas, M.; Steenbergen, W.; Seyger, M.M.B.

    2015-01-01

    BACKGROUND: Vascular modifications represent a key feature in psoriatic plaques. Previous research with Laser Doppler Perfusion Imaging (LDPI) revealed a remarkable heterogeneity in the cutaneous perfusion within homogenous-appearing psoriatic lesions. Insights in the relation between perfusion duri

  13. Quantitative multiphoton imaging

    Science.gov (United States)

    König, Karsten; Weinigel, Martin; Breunig, Hans Georg; Uchugonova, Aisada

    2014-02-01

    Certified clinical multiphoton tomographs for label-free multidimensional high-resolution in vivo imaging have been introduced to the market several years ago. Novel tomographs include a flexible 360° scan head attached to a mechanooptical arm for autofluorescence and SHG imaging as well as a CARS module. Non-fluorescent lipids and water, mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen can be imaged in vivo with submicron resolution in human skin. Sensitive and rapid detectors allow single photon counting and the construction of 3D maps where the number of detected photons per voxel is depicted. Intratissue concentration profiles from endogenous as well exogenous substances can be generated when the number of detected photons can be correlated with the number of molecules with respect to binding and scattering behavior. Furthermore, the skin ageing index SAAID based on the ratio elastin/collagen as well as the epidermis depth based on the onset of SHG generation can be determined.

  14. Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

    2014-04-01

    Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g)-1, cardiac output = 3, 5, 8 L min-1). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This suggests that

  15. Cerebral perfusion imaging with bolus harmonic imaging (Honorable Mention Poster Award)

    Science.gov (United States)

    Kier, Christian; Toth, Daniel; Meyer-Wiethe, Karsten; Schindler, Angela; Cangur, Hakan; Seidel, Gunter; Aach, Til

    2005-04-01

    Fast visualisation of cerebral microcirculation supports diagnosis of acute stroke. However, the commonly used CT/MRI-based methods are time consuming, costly and not applicable to every patient. The bolus perfusion harmonic imaging (BHI) method is an ultrasound imaging technique which makes use of the fact, that ultrasound contrast agents unlike biological tissues resonate at harmonic frequencies. Exploiting this effect, the contrast between perfused and non-perfused areas can be improved. Thus, BHI overcomes the low signal-to-noise ratio of transcranial ultrasound and the high impedance of the skull. By analysing image sequences, visualising the qualitative characteristics of an US contrast agent bolus injection becomes possible. The analysis consists of calculating four perfusion-related parameters, Local Peak Intensity, Time To Peak, Area Under Curve, and Average Rising, from the time/intensity curve and providing them as colour-coded images. For calculating these parameters the fundamental assumption is that image intensity corresponds to contrast agent concentration which in turn shows the perfusion of the corresponding brain region. In a clinical study on patients suffering from acute ischemic stroke it is shown that some of the parameters correlate significantly to the infarction area. Thus, BHI becomes a less time-consuming and inexpensive bedside method for diagnosis of cerebral perfusion deficits.

  16. 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.

  17. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

    NARCIS (Netherlands)

    A. Coenen (Adriaan); M. Lubbers (Marisa); A. Kurata (Akira); A.K. Kono (Atsushi K.); A. Dedic (Admir); R.G. Chelu (Raluca Gabriela); M.L. Dijkshoorn (Marcel); Rossi, A. (Alexia); R.J.M. van Geuns (Robert Jan); K. Nieman (Koen)

    2016-01-01

    textabstractObjectives: To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Methods: Subjects with suspected or known coro

  18. Quantitative myocardial perfusion by O-15-water PET

    DEFF Research Database (Denmark)

    Thomassen, Anders; Petersen, Henrik; Johansen, Allan

    2015-01-01

    disease (CAD). METHODS AND RESULTS: Forty-four patients with suspected CAD were included prospectively and underwent coronary CT-angiography and quantitative MBF assessment with O-15-water PET followed by invasive, quantitative coronary angiography, which served as reference. MBF was calculated...... in this particular territory. CONCLUSION: Disparity between standardized and individualized vascular territories was present in half of the patients, but had little clinical impact. Still, caution should be taken not always to rely on standard territories, as this may at times cause misinterpretation....

  19. Double-echo perfusion-weighted MR imaging: basic concepts and application in brain tumors for the assessment of tumor blood volume and vascular permeability

    OpenAIRE

    Uematsu, Hidemasa; Maeda, Masayuki

    2006-01-01

    Perfusion-weighted magnetic resonance (MR) imaging using contrast agents plays a key role in characterizing tumors of the brain. We have shown that double-echo perfusion-weighted MR imaging (DEPWI) is potentially useful in assessing brain tumors. Quantitative indices, such as tumor blood volume, are obtained using DEPWI, which allows correction of underestimation of tumor blood volume due to leakage of contrast agents from tumor vessels, in addition to simultaneous acquisition of tumor vessel...

  20. Quantitative phase imaging of arthropods

    Science.gov (United States)

    Sridharan, Shamira; Katz, Aron; Soto-Adames, Felipe; Popescu, Gabriel

    2015-01-01

    Abstract. Classification of arthropods is performed by characterization of fine features such as setae and cuticles. An unstained whole arthropod specimen mounted on a slide can be preserved for many decades, but is difficult to study since current methods require sample manipulation or tedious image processing. Spatial light interference microscopy (SLIM) is a quantitative phase imaging (QPI) technique that is an add-on module to a commercial phase contrast microscope. We use SLIM to image a whole organism springtail Ceratophysella denticulata mounted on a slide. This is the first time, to our knowledge, that an entire organism has been imaged using QPI. We also demonstrate the ability of SLIM to image fine structures in addition to providing quantitative data that cannot be obtained by traditional bright field microscopy. PMID:26334858

  1. Quantitative Tc-99m myocardial perfusion SPECT with 180[degree] acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Ye, J.

    1992-01-01

    Myocardial perfusion single photon emission computed tomography (SPECT) images using 180[degrees] acquisition are degraded by the effects of scatter, nonuniform attenuation and system geometric resolution variation with source depth. Using a 180[degrees] scan orbit which is closer to the heart may provide higher image resolution, signal-to-noise ratio and defect-to-normal contrast than using a 360[degrees] orbit, however, significant object shape distortion has been observed in the 180[degrees] reconstructed images. A method has been developed that combines filtered back-projection (FBP) with iterative attenuation and three-dimensional (3-D) resolution compensation for Tc-99m myocardial perfusion imaging, data. The non-uniform attenuation coefficient distribution is obtained by a quick transmission scan using a flood source and segmentation of the reconstructed transmission image to define areas of significantly different attenuation. A priori attenuation coefficients are assigned to the areas to form the attenuation distribution map. The 3-D correction is accomplished by including both the non-uniform attenuation and depth-dependent resolution variation in the reprojection procedure of an iterative correction algorithm. The method was evaluated with both simulated and experimental data using clinical protocols with a cardiac phantom. A significant improvement in image resolution was observed with line source images was reduced from approximately 10 mm to 7.l5 mm after 7 iterations of the 3-D correction. The contrast of two perfusion defects to the surrounding normally perfused regions was significantly improved with the correction. Significant improvement in uniformity at different positions in the 100% perfused areas in the myocardium was also observed. The normalized root squared error (NRSE) of one transaxial image from the original source distribution in the simulation study was reduced from 0.8 to 0.2 after 5 iterations of the 3-D correction.

  2. Dynamic CT perfusion image data compression for efficient parallel processing.

    Science.gov (United States)

    Barros, Renan Sales; Olabarriaga, Silvia Delgado; Borst, Jordi; van Walderveen, Marianne A A; Posthuma, Jorrit S; Streekstra, Geert J; van Herk, Marcel; Majoie, Charles B L M; Marquering, Henk A

    2016-03-01

    The increasing size of medical imaging data, in particular time series such as CT perfusion (CTP), requires new and fast approaches to deliver timely results for acute care. Cloud architectures based on graphics processing units (GPUs) can provide the processing capacity required for delivering fast results. However, the size of CTP datasets makes transfers to cloud infrastructures time-consuming and therefore not suitable in acute situations. To reduce this transfer time, this work proposes a fast and lossless compression algorithm for CTP data. The algorithm exploits redundancies in the temporal dimension and keeps random read-only access to the image elements directly from the compressed data on the GPU. To the best of our knowledge, this is the first work to present a GPU-ready method for medical image compression with random access to the image elements from the compressed data.

  3. 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

  4. 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

  5. Quantitative analysis of CT-perfusion parameters in the evaluation of brain gliomas and metastases

    Directory of Open Access Journals (Sweden)

    Di Nallo Anna

    2009-03-01

    Full Text Available Abstract Background The paper reports a quantitative analysis of the perfusion maps of 22 patients, affected by gliomas or by metastasis, with the aim of characterizing the malignant tissue with respect to the normal tissue. The gold standard was obtained by histological exam or nuclear medicine techniques. The perfusion scan provided 11 parametric maps, including Cerebral Blood Volume (CBV, Cerebral Blood Flow (CBF, Average Perfusion (Pmean and Permeability-surface area product (PS. Methods The perfusion scans were performed after the injection of 40 ml of non-ionic contrast agent, at an injection rate of 8 ml/s, and a 40 s cine scan with 1 s interval was acquired. An expert radiologist outlined the region of interest (ROI on the unenhanced CT scan, by using a home-made routine. The mean values with their standard deviations inside the outlined ROIs and the contralateral ROIs were calculated on each map. Statistical analyses were used to investigate significant differences between diseased and normal regions. Receiving Operating Characteristic (ROC curves were also generated. Results Tumors are characterized by higher values of all the perfusion parameters, but after the statistical analysis, only the PS, PatRsq (Patlak Rsquare and Tpeak (Time to Peak resulted significant. ROC curves, confirmed both PatRsq and PS as equally reliable metrics for discriminating between malignant and normal tissues, with areas under curves (AUCs of 0.82 and 0.81, respectively. Conclusion CT perfusion is a useful and non invasive technique for evaluating brain neoplasms. Malignant and normal tissues can be accurately differentiated using perfusion map, with the aim of performing tumor diagnosis and grading, and follow-up analysis.

  6. [Examination of R-L shunt ratio mensuration using dynamic images in lung perfusion scintigraphy].

    Science.gov (United States)

    Ichikawa, Hajime; Yamada, Sayaka; Yoshioka, Chiho; Tamaoki, Toyoshi; Miura, Syunichi; Suzuki, Motoki; Makino, Tetsuzou

    2008-05-20

    We examined a method of quantitative analysis that used dynamic and static images to measure the Right-left (R-L) shunt ratio in lung perfusion scintigraphy. A total of 18 patients suspected of having R-L shunt brought on by congenital heart disease were referred for lung perfusion scintigraphy from November 2005 to February 2007 at our hospital. We acquired anterior dynamic images, set ROIs in all fields of view, and measured the highest count. We acquired anterior and posterior static images of the chest and measured lung counts. We considered the highest count on dynamic images to be the total injection dose per one second, normalized the acquisition time of static images, and calculated the R-L shunt ratio. We weighed the measurement results of the R-L shunt ratio obtained by the dynamic method against that of the whole-body method by t-test and the least-squares method. When we used a posterior static image in the dynamic method, we found that the coefficient of correlation (r) was 0.9831. The result of the t-test was that there was no significant difference at a level of significance of 1%. We think the use of the dynamic method is possible in R-L shunt ratio measurement and can shorten the examination time.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Daniela Muenzel

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

  9. Quantitative ultrasound in cancer imaging.

    Science.gov (United States)

    Feleppa, Ernest J; Mamou, Jonathan; Porter, Christopher R; Machi, Junji

    2011-02-01

    Ultrasound is a relatively inexpensive, portable, and versatile imaging modality that has a broad range of clinical uses. It incorporates many imaging modes, such as conventional gray-scale "B-mode" imaging to display echo amplitude in a scanned plane; M-mode imaging to track motion at a given fixed location over time; duplex, color, and power Doppler imaging to display motion in a scanned plane; harmonic imaging to display nonlinear responses to incident ultrasound; elastographic imaging to display relative tissue stiffness; and contrast-agent imaging with simple contrast agents to display blood-filled spaces or with targeted agents to display specific agent-binding tissue types. These imaging modes have been well described in the scientific, engineering, and clinical literature. A less well-known ultrasonic imaging technology is based on quantitative ultrasound (QUS), which analyzes the distribution of power as a function of frequency in the original received echo signals from tissue and exploits the resulting spectral parameters to characterize and distinguish among tissues. This article discusses the attributes of QUS-based methods for imaging cancers and providing improved means of detecting and assessing tumors. The discussion will include applications to imaging primary prostate cancer and metastatic cancer in lymph nodes to illustrate the methods. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Inter-observer agreement and diagnostic accuracy of myocardial perfusion reserve quantification by cardiovascular magnetic resonance at 3 Tesla in comparison to quantitative coronary angiography.

    Science.gov (United States)

    Ikuye, Katharina; Buckert, Dominik; Schaaf, Lisa; Walcher, Thomas; Rottbauer, Wolfgang; Bernhardt, Peter

    2013-03-27

    Quantification of cardiovascular magnetic resonance (CMR) myocardial perfusion reserve (MPR) at 1.5 Tesla has been shown to correlate to invasive evaluation of coronary artery disease (CAD) and to yield good inter-observer agreement. However, little is known about quantitative adenosine-perfusion CMR at 3 Tesla and no data about inter-observer agreement is available. Aim of our study was to evaluate inter-observer agreement and to assess the diagnostic accuracy in comparison to quantitative coronary angiography (QCA). Fifty-three patients referred for coronary x-ray angiography were previously examined in a 3 Tesla whole-body scanner. Adenosine and rest perfusion CMR were acquired for the quantification of MPR in all segments. Two blinded and independent readers analyzed all images. QCA was performed in case of coronary stenosis. QCA data was used to assess diagnostic accuracy of the MPR measurements. Inter-observer agreement was high for all myocardial perfusion territories (ρ = 0.92 for LAD, ρ = 0.93 for CX and RCA perfused segments). Compared to QCA receiver-operating characteristics yielded an area under the curve of 0.78 and 0.73 for RCA, 0.66 and 0.69 for LAD, and 0.52 and 0.53 for LCX perfused territories. Inter-observer agreement of MPR quantification at 3 Tesla CMR is very high for all myocardial segments. Diagnostic accuracy in comparison to QCA yields good values for the RCA and LAD perfused territories, but moderate values for the posterior LCX perfused myocardial segments.

  11. Quality of myocardial perfusion single-photon emission tomography imaging: multicentre evaluation with a cardiac phantom.

    Science.gov (United States)

    Heikkinen, J; Ahonen, A; Kuikka, J T; Rautio, P

    1999-10-01

    The aim of the study was to evaluate quality of myocardial perfusion single-photon emission tomography (SPET) imaging in Finnish hospitals. Nineteen nuclear medicine departments participated in the study. A myocardial phantom simulating clinical stress and rest conditions was filled with routinely used isotope solution (technetium-99m or thallium-201). The cardiac insert included three reversible defects (simulating ischaemia): 30x30x14 mm(3) septal (90% recovery at rest), 30x20x14 mm(3) posterobasal (full recovery) and 20x20x14 mm(3) lateral (full recovery). There were two fixed defects (simulating infarct): 30x20x14 mm(3) postero-apical and 10x10x6 mm(3) apical. The phantom was imaged and interpreted as a myocardial perfusion patient. Reconstruction, printout and reporting were performed according to the clinical routine of each centre. Three nuclear medicine specialists anonymously evaluated the quality of the image sets. The visual scores of the experts were ranked from 1 to 5. Additionally, points from 0 to 8 were given to research reports according to how well perfusion defects were detected. Quantitative points were calculated by comparing background-subtracted and -normalized counts from 12 regions of interest between stress and rest images. Results for technetium studies (12 departments) were better than those for thallium (7 departments). The average visual scores of the experts were 3.7+/-0. 9 for all image sets, 3.2+/-0.5 for thallium users and 3.9+/-0.6 for technetium users (P=0.003). Five laboratories received a low score which, according to the specialists, is barely sufficient for limited clinical use. Average points for the reports were 5.6+/-2.1, 4.9+/-1.5 and 6.5+/-1.7 (P=0.051), and for the quantitation 8.2+/-1. 0, 7.9+/-0.4 and 8.4+/-1.1 (P=0.185), respectively. Seven out of 22 interpreters did not detect the lateral 20x20x14 mm(3) defect; five of them used thallium. This study demonstrated the heterogeneity of myocardial perfusion SPET in

  12. Quality of myocardial perfusion single-photon emission tomography imaging: multicentre evaluation with a cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    Heikkinen, J. [Dept. of Nuclear Medicine, Etela-Savo Hospital District, Mikkeli Central Hospital, Mikkeli (Finland); Ahonen, A. [Dept. of Nuclear Medicine, Oulu University Hospital (Finland); Kuikka, J.T. [Dept. of Clinical Physiology, Kuopio University Hospital and Niuvanniemi Hospital, Kuopio (Finland); Rautio, P. [Dept. of Clinical Physiology, North Karelia Central Hospital, Joensuu (Finland)

    1999-10-01

    The aim of the study was to evaluate quality of myocardial perfusion single-photon emission tomography (SPET) imaging in Finnish hospitals. Nineteen nuclear medicine departments participated in the study. A myocardial phantom simulating clinical stress and rest conditions was filled with routinely used isotope solution (technetium-99m or thallium-201). The cardiac insert included three reversible defects (simulating ischaemia): 30 x 30 x 14 mm{sup 3} septal (90% recovery at rest), 30 x 20 x 14 mm{sup 3} posterobasal (full recovery) and 20 x 20 x 14 mm{sup 3} lateral (full recovery). There were two fixed defects (simulating infarct): 30 x 20 x 14 mm{sup 3} postero-apical and 10 x 10 x 6 mm{sup 3} apical. The phantom was imaged and interpreted as a myocardial perfusion patient. Reconstruction, printout and reporting were performed according to the clinical routine of each centre. Three nuclear medicine specialists anonymously evaluated the quality of the image sets. The visual scores of the experts were ranked from 1 to 5. Additionally, points from 0 to 8 were given to research reports according to how well perfusion defects were detected. Quantitative points were calculated by comparing background-subtracted and -normalized counts from 12 regions of interest between stress and rest images. Results for technetium studies (12 departments) were better than those for thallium (7 departments). The average visual scores of the experts were 3.7{+-}0.9 for all image sets, 3.2{+-}0.5 for thallium users and 3.9{+-}0.6 for technetium users (P=0.003). Five laboratories received a low score which, according to the specialists, is barely sufficient for limited clinical use. Average points for the reports were 5.6{+-}2.1, 4.9{+-}1.5 and 6.5{+-}1.7 (P=0.051), and for the quantitation 8.2{+-}1.0, 7.9{+-}0.4 and 8.4{+-}1.1 (P=0.185), respectively. Seven out of 22 interpreters did not detect the lateral 20 x 20 x 14 mm{sup 3} defect; five of them used thallium. This study demonstrated

  13. GPC and quantitative phase imaging

    DEFF Research Database (Denmark)

    Palima, Darwin; Banas, Andrew Rafael; Villangca, Mark Jayson

    2016-01-01

    shaper followed by the potential of GPC for biomedical and multispectral applications where we experimentally demonstrate the active light shaping of a supercontinuum laser over most of the visible wavelength range. Finally, we discuss how GPC can be advantageously applied for Quantitative Phase Imaging...

  14. Perfusion magnetic resonance imaging with continuous arterial spin labeling: methods and clinical applications in the central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Detre, John A. E-mail: detre@mail.med.upenn.edu; Alsop, David C

    1999-05-01

    Several methods are now available for measuring cerebral perfusion and related hemodynamic parameters using magnetic resonance imaging (MRI). One class of techniques utilizes electromagnetically labeled arterial blood water as a noninvasive diffusible tracer for blood flow measurements. The electromagnetically labeled tracer has a decay rate of T1, which is sufficiently long to allow perfusion of the tissue and microvasculature to be detected. Alternatively, electromagnetic arterial spin labeling (ASL) may be used to obtain qualitative perfusion contrast for detecting changes in blood flow, similar to the use of susceptibility contrast in blood oxygenation level dependent functional MRI (BOLD fMRI) to detect functional activation in the brain. The ability to obtain blood flow maps using a non-invasive and widely available modality such as MRI should greatly enhance the utility of blood flow measurement as a means of gaining further insight into the broad range of hemodynamically related physiology and pathophysiology. This article describes the biophysical considerations pertaining to the generation of quantitative blood flow maps using a particular form of ASL in which arterial blood water is continuously labeled, termed continuous arterial spin labeling (CASL). Technical advances permit multislice perfusion imaging using CASL with reduced sensitivity to motion and transit time effects. Interpretable cerebral perfusion images can now be reliably obtained in a variety of clinical settings including acute stroke, chronic cerebrovascular disease, degenerative diseases and epilepsy. Over the past several years, the technical and theoretical foundations of CASL perfusion MRI techniques have evolved from feasibility studies into practical usage. Currently existing methodologies are sufficient to make reliable and clinically relevant observations which complement structural assessment using MRI. Future technical improvements should further reduce the acquisition times

  15. Non-invasive assessment of functionally relevant coronary artery stenoses with quantitative CT perfusion: preliminary clinical experiences

    Energy Technology Data Exchange (ETDEWEB)

    So, Aaron [Lawson Health Research Institute, Imaging Program, London, Ontario (Canada); Robarts Research Institute, Imaging Research Laboratories, London, Ontario (Canada); University of Western Ontario, Medical Biophysics, London, Ontario (Canada); Wisenberg, Gerald [Lawson Health Research Institute, Imaging Program, London, Ontario (Canada); University of Western Ontario, Medical Biophysics, London, Ontario (Canada); University of Western Ontario, Medical Imaging, London, Ontario (Canada); London Health Sciences Centre, Cardiology, London, Ontario (Canada); Islam, Ali; Amann, Justin; Romano, Walter [University of Western Ontario, Medical Imaging, London, Ontario (Canada); St. Joseph' s Health Care, Radiology, London, Ontario (Canada); Brown, James; Humen, Dennis; Jablonsky, George [London Health Sciences Centre, Cardiology, London, Ontario (Canada); Li, Jian-Ying; Hsieh, Jiang [GE Healthcare, CT Engineering, Waukesha, Wisconsin (United States); Lee, Ting-Yim [Lawson Health Research Institute, Imaging Program, London, Ontario (Canada); Robarts Research Institute, Imaging Research Laboratories, London, Ontario (Canada); University of Western Ontario, Medical Biophysics, London, Ontario (Canada); University of Western Ontario, Medical Imaging, London, Ontario (Canada)

    2012-01-15

    We developed a quantitative Dynamic Contrast-Enhanced CT (DCE-CT) technique for measuring Myocardial Perfusion Reserve (MPR) and Volume Reserve (MVR) and studied their relationship with coronary stenosis. Twenty-six patients with Coronary Artery Disease (CAD) were recruited. Degree of stenosis in each coronary artery was classified from catheter-based angiograms as Non-Stenosed (NS, angiographically normal or mildly irregular), Moderately Stenosed (MS, 50-80% reduction in luminal diameter), Severely Stenosed (SS, >80%) and SS with Collaterals (SSC). DCE-CT at rest and after dipyridamole infusion was performed using 64-slice CT. Mid-diastolic heart images were corrected for beam hardening and analyzed using proprietary software to calculate Myocardial Blood Flow (MBF, in mLmin{sup -1}100 g{sup -1}) and Blood Volume (MBV, in mL100 g{sup -1}) parametric maps. MPR and MVR in each coronary territory were calculated by dividing MBF and MBV after pharmacological stress by their respective baseline values. MPR and MVR in MS and SS territories were significantly lower than those of NS territories (p < 0.05 for all). Logistic regression analysis identified MPR MVR as the best predictor of {>=}50% coronary lesion than MPR or MVR alone. DCE-CT imaging with quantitative CT perfusion analysis could be useful for detecting coronary stenoses that are functionally significant. (orig.)

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

    Science.gov (United States)

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

    2010-05-01

    Coronary artery disease (CAD) is the most prevalent form of cardiovascular disease affecting about 13 million Americans, while more than one million percutaneous transluminal intervention (PCI) procedures are performed annually in the USA. The relative high occurrence of restenosis, despite stent implementation, seems to be the primary limitation of PCI. Over the last decades, single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), has proven an invaluable tool for the diagnosis of CAD and patients' risk stratification, providing useful information regarding the decision about revascularization and is well suited to assess patients after intervention. Information gained from post-intervention MPI is crucial to differentiate patients with angina from those with exo-cardiac chest pain syndromes, to assess peri-intervention myocardial damage, to predict-detect restenosis after PCI, to detect CAD progression in non-revascularized vessels, to evaluate the effects of intervention if required for occupational reasons and to evaluate patients' long-term prognosis. On the other hand, chest pain and exercise electrocardiography are largely unhelpful in identifying patients at risk after PCI.Although there are enough published data demonstrating the value of myocardial perfusion SPECT imaging in patients after PCI, there is still debate on whether or not these tests should be performed routinely.

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

    Science.gov (United States)

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

    1993-07-01

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

  18. Radiation exposure for medical staff performing quantitative coronary perfusion PET with 13N-ammonia

    DEFF Research Database (Denmark)

    Kristoffersen, Ulrik Sloth; Borgwardt, Henrik Gutte; Skovgaard, Dorthe Charlotte

    2009-01-01

    PURPOSE: To evaluate radiation doses to medical staff performing quantitative (13)N-ammonia myocardial perfusion positron emission tomography (PET). METHODS: Seventeen PET examinations were performed. Nine examinations consisted of two PET scans (one during rest and one after pharmacological stress......-ammonia exposes the staff to radiation doses that are comparable to doses from (18)F-fluoro-deoxy-glucose scans and the annual doses are well within the recommended upper limits for radiation workers....

  19. Justification of administered dose level in brain perfusion imaging with 99mTc-HMPAO

    Science.gov (United States)

    Stefanoyiannis, A. P.; Gerogiannis, I.; Geronikola-Trapali, X.; Armeniakos, I.; Prentakis, A.; Soultanis, S.; Chatziioannou, S. N.

    2011-09-01

    Brain perfusion imaging by means of 99mTc-HMPAO is widely used in the diagnosis of Alzheimer's disease. The administered dose range recommended by the manufacturer and reported in bibliography is rather wide (~ 9.5 - 27 mCi), necessitating further quantitative analysis. In the framework of this study, a quantitative evaluation of the radiopharmaceutical performance for different values of administered dose was carried out, based on image quality indicators. Evaluation of image quality was based on wavelet-generated contrast, noise, and contrast-to-noise ratio indicators, denoted as CI, NI and CNR respectively. Subsequently, a generic image quality index was correlated with the administered dose, to produce an overall performance indicator (denoted as PI). Application of appropriate statistical tests (analysis of variance for normal and Kruskal-Wallis test for non-normal distributions) showed that there is a statistically significant difference in CI (p 0.05) values. Application of Tukey test for CI and NI normal distributions demonstrated that CI (10 mCi) = CI (20 mCi) NI (20 mCi), while NI (15 mCi) could not be characterised. Finally, application of non-parametric multiple comparisons showed that CNR (20 mCi) < CNR (10 mCi), while CNR (15 mCi) could not be characterised. Consequently, brain perfusion imaging, by means of 99mTc-HMPAO utilising an administered dose of 20 mCi, results in improved image quality on the basis of the estimated indicators. Additionally, this image quality improvement is sufficient to justify the increased patient radiation burden.

  20. 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.)

  1. Whole tumour perfusion of peripheral lung carcinoma: evaluation with first-pass CT perfusion imaging at 64-detector row CT

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y. [Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan (China); Yang, Z.-G. [Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan (China); National Key Laboratory of Biotherapy Center, West China Hospital, Sichuan University, Chengdu, Sichuan (China)], E-mail: yangzg1117@yahoo.com.cn; Chen, T.-w.; Deng, Y.-p.; Yu, J.-q.; Li, Z.-l. [Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan (China)

    2008-06-15

    Aim: To prospectively assess the feasibility of a whole-tumour perfusion technique using 64-detector row computed tomography (CT) and to analyse the variation of CT perfusion parameters in different histological types, sizes, and metastases in patients with peripheral lung carcinoma. Methods and materials: Ninety-seven pathologically proved peripheral lung carcinomas (less than 5 cm in largest diameter) underwent dynamic contrast-enhanced CT using a 64-detector row CT machine. Small amounts of iodinated contrast medium with a sharp bolus profile (50 ml, 6-7 ml/s), and 12 repeated fast acquisitions encompassing the entire tumour lesion were adopted to quantify perfusion of the whole-tumour during first-pass of contrast medium. Four kinetic parameters, including perfusion, peak enhancement intensity (PEI), time to peak (TTP), and blood volume (BV), were measured and statistically compared among different histological types, sizes, and metastases. Results: Mean values for perfusion, PEI, TTP, and BV of the 97 lung carcinomas were 57.5 {+-} 45.4 ml/min/ml (range 5.9-243 ml/min/ml), 53.4 {+-} 40.6 HU (range 10.3-234.4 HU), 34 {+-} 11 s (range 11-60 s), and 30.1 {+-} 21.7 ml/100 g (range 3.9-113.4 ml/100 g), respectively. No statistical differences were found between the histological types regarding the perfusion parameters (p > 0.05). Perfusion, PEI, and BV of stage T2 tumours were significantly lower than those of stage T1 tumours (all p < 0.05), whereas no statistically significant differences was found between other stages of tumours (all p > 0.05). Perfusion of the tumours with distant metastasis was significantly higher than that of the tumours without distant metastasis (p < 0.05), but there was no statistically significant difference between nodal metastasis positive and negative groups (p > 0.05). Conclusion: The present study of first-pass perfusion imaging using 64-detector row CT could provide a feasible method for assessment of whole-tumour perfusion. CT

  2. 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...

  3. Multimodal tissue perfusion imaging using multi-spectral and thermographic imaging systems applied on clinical data

    Science.gov (United States)

    Klaessens, John H. G. M.; Nelisse, Martin; Verdaasdonk, Rudolf M.; Noordmans, Herke Jan

    2013-03-01

    Clinical interventions can cause changes in tissue perfusion, oxygenation or temperature. Real-time imaging of these phenomena could be useful for surgical strategy or understanding of physiological regulation mechanisms. Two noncontact imaging techniques were applied for imaging of large tissue areas: LED based multispectral imaging (MSI, 17 different wavelengths 370 nm-880 nm) and thermal imaging (7.5 to 13.5 μm). Oxygenation concentration changes were calculated using different analyzing methods. The advantages of these methods are presented for stationary and dynamic applications. Concentration calculations of chromophores in tissue require right choices of wavelengths The effects of different wavelength choices for hemoglobin concentration calculations were studied in laboratory conditions and consequently applied in clinical studies. Corrections for interferences during the clinical registrations (ambient light fluctuations, tissue movements) were performed. The wavelength dependency of the algorithms were studied and wavelength sets with the best results will be presented. The multispectral and thermal imaging systems were applied during clinical intervention studies: reperfusion of tissue flap transplantation (ENT), effectiveness of local anesthetic block and during open brain surgery in patients with epileptic seizures. The LED multispectral imaging system successfully imaged the perfusion and oxygenation changes during clinical interventions. The thermal images show local heat distributions over tissue areas as a result of changes in tissue perfusion. Multispectral imaging and thermal imaging provide complementary information and are promising techniques for real-time diagnostics of physiological processes in medicine.

  4. Perfusion lung imaging in the adult respiratory distress syndrome

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-07-01

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

  5. Diagnostic accuracy of combined coronary angiography and adenosine stress myocardial perfusion imaging using 320-detector computed tomography: pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Nasis, Arthur; Ko, Brian S.; Leung, Michael C.; Antonis, Paul R.; Wong, Dennis T.; Kyi, Leo; Cameron, James D.; Meredith, Ian T.; Seneviratne, Sujith K. [Southern Health and Monash University, Monash Cardiovascular Research Centre, Monash Heart, Department of Medicine Monash Medical Centre (MMC), Melbourne (Australia); Nandurkar, Dee; Troupis, John M. [MMC, Southern Health, Department of Diagnostic Imaging, Melbourne (Australia)

    2013-07-15

    To determine the diagnostic accuracy of combined 320-detector row computed tomography coronary angiography (CTA) and adenosine stress CT myocardial perfusion imaging (CTP) in detecting perfusion abnormalities caused by obstructive coronary artery disease (CAD). Twenty patients with suspected CAD who underwent initial investigation with single-photon-emission computed tomography myocardial perfusion imaging (SPECT-MPI) were recruited and underwent prospectively-gated 320-detector CTA/CTP and invasive angiography. Two blinded cardiologists evaluated invasive angiography images quantitatively (QCA). A blinded nuclear physician analysed SPECT-MPI images for fixed and reversible perfusion defects. Two blinded cardiologists assessed CTA/CTP studies qualitatively. Vessels/territories with both >50 % stenosis on QCA and corresponding perfusion defect on SPECT-MPI were defined as ischaemic and formed the reference standard. All patients completed the CTA/CTP protocol with diagnostic image quality. Of 60 vessels/territories, 17 (28 %) were ischaemic according to QCA/SPECT-MPI criteria. Sensitivity, specificity, PPV, NPV and area under the ROC curve for CTA/CTP was 94 %, 98 %, 94 %, 98 % and 0.96 (P < 0.001) on a per-vessel/territory basis. Mean CTA/CTP radiation dose was 9.2 {+-} 7.4 mSv compared with 13.2 {+-} 2.2 mSv for SPECT-MPI (P < 0.001). Combined 320-detector CTA/CTP is accurate in identifying obstructive CAD causing perfusion abnormalities compared with combined QCA/SPECT-MPI, achieved with lower radiation dose than SPECT-MPI. (orig.)

  6. Prior image constrained compressed sensing: a quantitative performance evaluation

    Science.gov (United States)

    Thériault Lauzier, Pascal; Tang, Jie; Chen, Guang-Hong

    2012-03-01

    The appeal of compressed sensing (CS) in the context of medical imaging is undeniable. In MRI, it could enable shorter acquisition times while in CT, it has the potential to reduce the ionizing radiation dose imparted to patients. However, images reconstructed using a CS-based approach often show an unusual texture and a potential loss in spatial resolution. The prior image constrained compressed sensing (PICCS) algorithm has been shown to enable accurate image reconstruction at lower levels of sampling. This study systematically evaluates an implementation of PICCS applied to myocardial perfusion imaging with respect to two parameters of its objective function. The prior image parameter α was shown here to yield an optimal image quality in the range 0.4 to 0.5. A quantitative evaluation in terms of temporal resolution, spatial resolution, noise level, noise texture, and reconstruction accuracy was performed.

  7. Usefulness of myocardial perfusion imaging with exercise testing in children.

    Science.gov (United States)

    Robinson, Brad; Goudie, Brett; Remmert, Jenna; Gidding, Samuel S

    2012-10-01

    Myocardial perfusion imaging (MPI) provides additional clinical information on children with cardiac disease but will not benefit children with chest pain and normal cardiac studies. This study reviewed all technetium-99 m ((99m)Tc) sestamibi stress MPI studies between 2004 and 2010 performed in association with graded exercise testing (86% with bicycle ergometer, 14% with treadmill). A positive test was defined as a perfusion defect or abnormal ventricular function response. Clinical records were reviewed, including follow-up assessment to determine accuracy of MPI interpretation. False-positive and false-negative rates were recorded. A total of 197 patients (mean age, 13.4 ± 3.6 years, 70% male) underwent 218 MPI studies. Group A had 42 patients (43 studies) with isolated chest pain and normal studies. Of the 43 studies, 39 had negative results, and 4 had false-positive results. Group B had 155 patients (175 studies) with known or suspected cardiac disease, and 39 tests (33 patients) had positive results. Whereas 32 studies were considered true-positive, 7 were false-positive. There was one false-negative test. According to the findings, (99m)Tc sestamibi MPI studies are clinically useful but not perfect tests in the setting of known or suspected cardiac disease based on clinical evaluation, electrocardiography (ECG), or echocardiography. Children who had isolated chest pain with a normal ECG and echocardiogram often have false-positive studies.

  8. The routine use of sublingual GTN with resting 99Tcm-tetrofosmin myocardial perfusion imaging.

    Science.gov (United States)

    Thorley, P J; Sheard, K L; Wright, D J; Sivananthan, U M

    1998-10-01

    Nitrates can be used to improve resting myocardial blood flow in patients with severe coronary artery disease. This may enhance tracer uptake during rest myocardial perfusion imaging. Recent studies using nitrates at rest have shown increased detection of reversible ischaemia in this patient group with the 201Tl and 99Tcm perfusion tracers MIBI and tetrofosmin. However, it is not always possible to assess the severity of coronary artery disease before the rest injection and therefore whether a patient would benefit from nitrate administration. To improve the sensitivity for the detection of reversible ischaemia and to avoid a repeat study with nitrates (especially in patients with 'fixed' defects), a protocol in which all patients routinely receive nitrates prior to the rest injection is required. This prospective study evaluated the effect of nitrate administration prior to rest imaging in a randomly selected group of patients. Thirty patients selected at random from routine referrals had stress, rest and rest + GTN tetrofosmin imaging on three separate days. Changes in reversibility between the rest and rest + GTN images were assessed both visually and using semi-quantitative analysis. Defects at stress were seen in 43 coronary artery territories, 33 of which were reversible at rest and 37 reversible at rest + GTN. Of these 43 defects, 82% demonstrated either increased or the same degree of reversibility at rest + GTN imaging compared to standard rest imaging. All defects with reduced reversibility at rest + GTN imaging (i.e. the remaining 18%) were, however, still reversible compared to the stress images. Some of this reduced reversibility may be due to attenuation artefacts. We conclude that the routine use of GTN with rest tetrofosmin imaging will result in increased detection of ischaemic areas with no loss of sensitivity or specificity.

  9. Myocardial perfusion imaging determination using an appropriate use smartphone application.

    Science.gov (United States)

    Mahajan, Ashish; Bal, Susan; Hahn, Harvey

    2015-02-01

    Inappropriate cardiac imaging has been a significant cost concern and cause of radiation burden to patients. To assess if a smartphone application (app) based on 2009 Appropriate Use Criteria (AUC) for Cardiac Radionuclide Imaging published by American College of Cardiology would be feasible at the point of order. We evaluated stress myocardial perfusion imaging (MPI) (N = 403) (mean age = 62.23 years; 47.89% males) over a 4 month period using a smartphone app to determine whether the study ordered was Appropriate, Inappropriate, or Uncertain per 2009 AUC. We also monitored the time needed to use the app to determine the level of appropriateness of each stress MPI. The results of the stress MPI were noted. Of the 403 stress MPIs evaluated, 267 (66.25%) were noted to be Appropriate, 118 (29.28%) were Inappropriate, and 13 (3.23%) were Uncertain, per AUC; 5 (1.25%) remained unclassified. Average time needed to use the app to assess each stress MPI for appropriateness was noted to be 44 (±9) seconds. Non-teaching physicians ordered 70 (38.89%) inappropriate stress MPIs as compared to 20 (23.53%) ordered by physicians on resident teaching service, and 28 (23.33%) by cardiologists (P = .0045). Among inappropriately ordered stress MPIs, 87 (42.65%) were ordered in females as compared to 31 (17.13%) in males (P stress MPIs among appropriately ordered were abnormal (reversible ischemia or fixed perfusion defect) as compared to 15 (12.17%) among inappropriately ordered stress MPIs (P = .0032). A free and convenient smartphone app provides an easy-to-use tool to assist physicians in determining the level of appropriateness of stress MPI in a time- and cost-effective manner at the point of order. The smartphone app may have potential to promote the usage of the AUC and possibly aid reduction of healthcare cost and ionizing radiation burden.

  10. Magnetic Resonance Perfusion Imaging in Malformations of Cortical Development

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-10-15

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

  11. Quantitative imaging as cancer biomarker

    Science.gov (United States)

    Mankoff, David A.

    2015-03-01

    The ability to assay tumor biologic features and the impact of drugs on tumor biology is fundamental to drug development. Advances in our ability to measure genomics, gene expression, protein expression, and cellular biology have led to a host of new targets for anticancer drug therapy. In translating new drugs into clinical trials and clinical practice, these same assays serve to identify patients most likely to benefit from specific anticancer treatments. As cancer therapy becomes more individualized and targeted, there is an increasing need to characterize tumors and identify therapeutic targets to select therapy most likely to be successful in treating the individual patient's cancer. Thus far assays to identify cancer therapeutic targets or anticancer drug pharmacodynamics have been based upon in vitro assay of tissue or blood samples. Advances in molecular imaging, particularly PET, have led to the ability to perform quantitative non-invasive molecular assays. Imaging has traditionally relied on structural and anatomic features to detect cancer and determine its extent. More recently, imaging has expanded to include the ability to image regional biochemistry and molecular biology, often termed molecular imaging. Molecular imaging can be considered an in vivo assay technique, capable of measuring regional tumor biology without perturbing it. This makes molecular imaging a unique tool for cancer drug development, complementary to traditional assay methods, and a potentially powerful method for guiding targeted therapy in clinical trials and clinical practice. The ability to quantify, in absolute measures, regional in vivo biologic parameters strongly supports the use of molecular imaging as a tool to guide therapy. This review summarizes current and future applications of quantitative molecular imaging as a biomarker for cancer therapy, including the use of imaging to (1) identify patients whose tumors express a specific therapeutic target; (2) determine

  12. Calibration free beam hardening correction for cardiac CT perfusion imaging

    Science.gov (United States)

    Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

  13. Comparison of rest and adenosine stress quantitative and semi-quantitative myocardial perfusion using magnetic resonance in patients with ischemic heart disease

    DEFF Research Database (Denmark)

    Qayyum, Abbas A; Qayyum, Faiza; Larsson, Henrik B W

    2017-01-01

    The aim was to compare absolute quantified myocardial perfusion (MP) to semi-quantitative measurements of MP using MRI for detection of ischemia. Twenty-nine patients underwent rest and stress MP imaging obtained by 1.5T MRI and analyzed using own developed software and by commercial available...... software. Linear regression analysis demonstrated that absolute quantitative data correlated stronger to maxSI (rest: r=0.296, p=.193; stress: r=0.583, p=0.011; myocardial perfusion reserve (MPR): r=0.789, prest: r=0.420, p=0.......058; stress: r=0.096, p=0.704; MPR: r=0.682, p=0.004; and Δ MBF: r=0.055, p=0.804). Absolute quantified MP was able to distinguish between ischemic and non-ischemic territories at rest (left anterior descending artery (LAD): 103.1±11.3mL/100g/min vs. 206.3±98.5mL/100g/min; p=0.001, right coronary artery (RCA...

  14. A novel quantitative dual-isotope method for simultaneous ventilation and perfusion lung SPET

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Crespo, Alejandro; Larsson, Stig A. [Section of Nuclear Medicine, Department of Hospital Physics, Karolinska Hospital, Stockholm (Sweden); Medical Radiation Physics, Department of Oncology-Pathology, Stockholm University and Karolinska Institute, Stockholm (Sweden); Petersson, Johan; Mure, Margareta; Lindahl, Sten G.E. [Department of Anaesthesiology and Intensive Care, Karolinska Hospital, Stockholm (Sweden); Nyren, Sven [Department of Radiology, Karolinska Hospital, Stockholm (Sweden); Glenny, Robb W. [University of Washington School of Medicine, Seattle (United States); Thorell, Jan-Olov [Karolinska Pharmacy, Stockholm (Sweden); Jacobsson, Hans [Section of Nuclear Medicine, Department of Hospital Physics, Karolinska Hospital, Stockholm (Sweden); Department of Radiology, Karolinska Hospital, Stockholm (Sweden)

    2002-07-01

    A quantitative dual-isotope single-photon emission tomography (SPET) technique for the assessment of lung ventilation (V) and perfusion (Q) using, respectively, technetium-99m labelled Technegas (140 keV) and indium-113m labelled macro-aggregated albumin (392 keV), is presented, validated and clinically tested in a healthy volunteer. In order to assess V, Q and V/Q distributions in quantitative terms, algorithms which correct for down scattering, photon scattering and attenuation, as well as an organ outline algorithm, were implemented. Scatter and down-scatter correction were made in the spatial domain by pixel-wise image subtraction of projection-dependent global scattering factors obtained from the energy domain. The attenuation correction was based on an iterative projection/back-projection method. All studies were made on a three-headed SPET system (Trionix) with medium-energy parallel-hole collimators. The set of input data for quantification was based on SPET acquisition of emission data in four separate energy windows, the associated cumulative energy spectra and transmission data. The attenuation correction routine as well as the edge detection algorithm utilized data from {sup 99m}Tc transmission tomography. Attenuation data for {sup 113m}In were obtained by linear scaling of the {sup 99m}Tc attenuation maps. The correction algorithms were experimentally validated with a stack phantom system and applied on a healthy volunteer. The mean difference between the corrected SPET data of the dense stack lung phantom and those obtained from the corresponding scatter- and attenuation-''free'' version was only 1.9% for {sup 99m}Tc and 0.9% for {sup 113m}In. The estimated fractional V/Q distribution in the 3-D lung phantom volume had its peak at V/Q=1, with a width (FWHM) of 0.31 due to noise, particularly in the {sup 113m}In images, and to partial volume effects. For a healthy volunteer, the corresponding values were 0.9 and 0.35, respectively

  15. Evaluation of Influence of Acupuncture and Electro-Acupuncture for Blood Perfusion of Stomach by Laser Doppler Blood Perfusion Imaging

    OpenAIRE

    Zhang Dong; Li Shun-Yue; Wang Shu-You; Ma Hui-Min

    2011-01-01

    The objective of this study is to observe effects of acupuncture and electro-acupuncture (EA) on blood perfusion in the stomach, and probe into the application of laser Doppler blood perfusion imaging technique in the study of the effect of acupuncture and moxibustion on the entrails. In the acupuncture group of 20 rats, acupuncture was given at “Zusanli” (ST 36) and in EA group of 18 rats, EA was applied at “Zusanli” (ST 36), with 18 rats without acupuncture used as control group. Changes of...

  16. Quantitative assessment of harmonic power doppler myocardial perfusion imaging with intravenous levovist™ in patients with myocardial infarction: comparison with myocardial viability evaluated by coronary flow reserve and coronary flow pattern of infarct-related artery

    Directory of Open Access Journals (Sweden)

    Nagai Kunihiko

    2005-08-01

    Full Text Available Abstract Background Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction. Aim To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography. Methods Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR. Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed. Results Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time ≧ 600 msec, Group B; 10 pts with deceleration time Conclusion The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction.

  17. Peripheral pulmonary nodules: Relationship between multi-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF expression

    Directory of Open Access Journals (Sweden)

    Cheng Xiao-Ling

    2008-06-01

    Full Text Available Abstract Background The aim of this study is to investigate the relationship between16-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF (vascular endothelial growth factor expression in patients with benign and malignant pulmonary nodules, and differential diagnosis between benign and malignant pulmonary nodules. Methods Sixty-four patients with benign and malignant pulmonary nodules underwent 16-slice spiral CT perfusion imaging. The CT perfusion imaging was analyzed for TDC (time density curve, perfusion parametric maps, and the respective perfusion parameters. Immunohistochemical findings of MVD (microvessel density measurement and VEGF expression was evaluated. Results The shape of the TDC of peripheral lung cancer was similar to those of inflammatory nodule. PH (peak height, PHpm/PHa (peak height ratio of pulmonary nodule to aorta, BF (blood flow, BV (blood volume value of peripheral lung cancer and inflammatory nodule were not statistically significant (all P > 0.05. Both showed significantly higher PH, PHpm/PHa, BF, BV value than those of benign nodule (all P 0.05. In the case of adenocarcinoma, BV, BF, PS, PHpm/PHa, and MVD between poorly and well differentiation and between poorly and moderately differentiation were statistically significant (all P 0.05. PH, PHpm/PHa, BV, and PS of benign nodule were significantly lower than those of peripheral lung cancer (all P Conclusion Multi-slice spiral CT perfusion imaging closely correlated with tumor angiogenesis and reflected MVD measurement and VEGF expression. It provided not only a non-invasive method of quantitative assessment for blood flow patterns of peripheral pulmonary nodules but also an applicable diagnostic method for peripheral pulmonary nodules.

  18. Diffusion and Perfusion MR Imaging in Acute Stroke: Clinical Utility and Potential Limitations for Treatment Selection

    DEFF Research Database (Denmark)

    Bateman, Mathew; Slater, Lee-Anne; Leslie-Mazwi, Thabele M

    2017-01-01

    Magnetic resonance (MR) diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) offer unique insight into acute ischemic stroke pathophysiology. These techniques may offer the ability to apply pathophysiology to accurately individualize acute stroke reperfusion treatment, including ...

  19. 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.

  20. Robust low-dose dynamic cerebral perfusion CT image restoration via coupled dictionary learning scheme.

    Science.gov (United States)

    Tian, Xiumei; Zeng, Dong; Zhang, Shanli; Huang, Jing; Zhang, Hua; He, Ji; Lu, Lijun; Xi, Weiwen; Ma, Jianhua; Bian, Zhaoying

    2016-11-22

    Dynamic cerebral perfusion x-ray computed tomography (PCT) imaging has been advocated to quantitatively and qualitatively assess hemodynamic parameters in the diagnosis of acute stroke or chronic cerebrovascular diseases. However, the associated radiation dose is a significant concern to patients due to its dynamic scan protocol. To address this issue, in this paper we propose an image restoration method by utilizing coupled dictionary learning (CDL) scheme to yield clinically acceptable PCT images with low-dose data acquisition. Specifically, in the present CDL scheme, the 2D background information from the average of the baseline time frames of low-dose unenhanced CT images and the 3D enhancement information from normal-dose sequential cerebral PCT images are exploited to train the dictionary atoms respectively. After getting the two trained dictionaries, we couple them to represent the desired PCT images as spatio-temporal prior in objective function construction. Finally, the low-dose dynamic cerebral PCT images are restored by using a general DL image processing. To get a robust solution, the objective function is solved by using a modified dictionary learning based image restoration algorithm. The experimental results on clinical data show that the present method can yield more accurate kinetic enhanced details and diagnostic hemodynamic parameter maps than the state-of-the-art methods.

  1. High-frequency Electrocardiogram Analysis in the Ability to Predict Reversible Perfusion Defects during Adenosine Myocardial Perfusion Imaging

    Science.gov (United States)

    Tragardh, Elin; Schlegel, Todd T.; Carlsson, Marcus; Pettersson, Jonas; Nilsson, Klas; Pahlm, Olle

    2007-01-01

    Background: A previous study has shown that analysis of high-frequency QRS components (HF-QRS) is highly sensitive and reasonably specific for detecting reversible perfusion defects on myocardial perfusion imaging (MPI) scans during adenosine. The purpose of the present study was to try to reproduce those findings. Methods: 12-lead high-resolution electrocardiogram recordings were obtained from 100 patients before (baseline) and during adenosine Tc-99m-tetrofosmin MPI tests. HF-QRS were analyzed regarding morphology and changes in root mean square (RMS) voltages from before the adenosine infusion to peak infusion. Results: The best area under the curve (AUC) was found in supine patients (AUC=0.736) in a combination of morphology and RMS changes. None of the measurements, however, were statistically better than tossing a coin (AUC=0.5). Conclusion: Analysis of HF-QRS was not significantly better than tossing a coin for determining reversible perfusion defects on MPI scans.

  2. Assessment value of quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Jiang-Xia Lei

    2016-01-01

    Objective:To analyze the assessment value of the quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer.Methods:A total of 58 patients with space-occupying pancreatic lesions were divided into 20 patients with pancreatic cancer and 38 patients with benign pancreatic lesions after pancreatic CT perfusion. Patients with pancreatic cancer received palliative surgery, and the cancer tissue and para-carcinoma tissue specimens were collected during operation. The differences in pancreatic CT perfusion scanning parameter values and serum tumor marker levels were compared between patients with pancreatic cancer and patients with benign pancreatic lesions, mRNA expression levels of malignant molecules in pancreatic cancer tissue and para-carcinoma tissue were further determined, and the correlation between pancreatic CT perfusion scanning parameter values and malignant degree of pancreatic cancer was analyzed.Results:CT perfusion scanning BF, BV and Per values of patients with pancreatic cancer were lower than those of patients with benign pancreatic lesions; serum CA19-9, CEA, CA125 and CA242 levels were higher than those of patients with benign pancreatic lesions (P<0.05); mRNA expression levels of Bcl-2, Bcl-xL andsurvivin in pancreatic cancer tissue samples were higher than those in para-carcinoma tissue samples, and mRNA expression levels ofP53 andBax were lower than those in para-carcinoma tissue samples (P<0.05); CT perfusion scanning parameters BF, BV and Per values of patients with pancreatic cancer were negatively correlated with CA19-9, CEA, CA125 and CA242 levels in serum as well as mRNA expression levels ofBcl-2, Bcl-xL and survivinin pancreatic cancer tissue, and positively correlated with mRNA expression levels ofP53andBaxin pancreatic cancer tissue (P<0.05).Conclusions:Pancreatic CT perfusion scanning is a reliable way to judge the malignant degree of pancreatic cancer and plays a positive role in guiding clinical

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

    Science.gov (United States)

    Li, Ke; Chen, Guang-Hong

    2016-03-01

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

  4. Assessment of tumor vascularization with functional computed tomography perfusion imaging in patients with cirrhotic liver disease

    Institute of Scientific and Technical Information of China (English)

    Jin-Ping Li; De-Li Zhao; Hui-Jie Jiang; Ya-Hua Huang; Da-Qing Li; Yong Wan; Xin-Ding Liu; Jin-E Wang

    2011-01-01

    BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignant tumor in China, and early diagnosis is critical for patient outcome. In patients with HCC, it is mostly based on liver cirrhosis, developing from benign regenerative nodules and dysplastic nodules to HCC lesions, and a better understanding of its vascular supply and the hemodynamic changes may lead to early tumor detection. Angiogenesis is essential for the growth of primary and metastatic tumors due to changes in vascular perfusion, blood volume and permeability. These hemodynamic and physiological properties can be measured serially using functional computed tomography perfusion (CTP) imaging and can be used to assess the growth of HCC. This study aimed to clarify the physiological characteristics of tumor angiogenesis in cirrhoticliverdiseasebythisfastimagingmethod. METHODS: CTP was performed in 30 volunteers without liver disease (control subjects) and 49 patients with liver disease (experimental subjects: 27 with HCC and 22 with cirrhosis). All subjects were also evaluated by physical examination, laboratory screening and Doppler ultrasonography of the liver. The diagnosis of HCC was made according to the EASL criteria. All patients underwent contrast-enhanced ultrasonography, pre- and post-contrast triple-phase CT and CTP study. A mathematical deconvolution model was applied to provide hepatic blood flow (HBF), hepatic blood volume (HBV), mean transit time (MTT), permeability of capillary vessel surface (PS), hepatic arterial index (HAI), hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP) data. The Mann-Whitney U test was used to determine differences in perfusion parameters between the background cirrhotic liver parenchyma and HCC and between the cirrhotic liver parenchyma with HCC and that without HCC. RESULTS: In normal liver, the HAP/HVP ratio was about 1/4. HCC had significantly higher HAP and HAI and lower HPP than background liver parenchyma adjacent to the HCC. The

  5. Perfusion weighted imaging and its application in stroke

    Science.gov (United States)

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

    2003-05-01

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

  6. 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...

  7. 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

  8. Contrast investigation of multi-slice spiral CT perfusion imaging and pathological findings in VX2 soft-tissue tumor of rabbits

    Institute of Scientific and Technical Information of China (English)

    Jingfeng Zhang; Renfa Wang; Min Wang; Jing Zhang; Jinmei Sang

    2005-01-01

    Objective: To perform a contrast investigation of multi-slice spiral CT (MSCT) perfusion imaging and pathological findings in VX2 soft-tissue tumor of rabbits, and discuss the applicative value of multi-slice spiral CT perfusion imaging in soft-tissue tumors. Methods: 8 Newzealand white rabbits were implanted with 0.1 ml VX2 tumor tissue suspension in bilateral proximal thighs. 14 days and 21 days later, CT plain scan and perfusion scan were performed on these rabbits respectively, then the images were transmitted to AW4.0 workstation, the functional maps and perfusion parameters including blood flow (BF), blood volume (BV), mean transit time(MTT) and permeability surface (PS) were computed and analyzed. Subsequently, the rabbits were sacrificed, the tumors of which were taken out for pathological examination. The correlation between MSCT functional parametric images and pathological findings was analyzed.Results: All the values of BF, BV and PS of VX2 soft-tissue tumors were obviously higher while the MTT-values were lower than those of the normal muscular tissues significantly ( P < 0.001). Conclusion: Multi-slice spiral CT perfusion imaging is an accurate, convenient and relatively safe functional imaging technique, which can give a quantitative assessment to blood perfusion and angiogenesis of soft-tissue tumors.

  9. Experimental Study of Quantitative Analysis of Canine Renal Blood Flow Perfusion in Power Doppler Imaging%能量多普勒显像定量分析犬肾血流灌注的实验研究

    Institute of Scientific and Technical Information of China (English)

    王建宏; 钱蕴秋; 贺建国; 朱霆; 赵振源; 李志宏

    2001-01-01

    Objective:To observe the accuracy of PDI in different canine renal blood perfusions by using computer analysis.Methods:Six healthy dogs were chosen and their main right renal arteries were exposed by surgery.Under the guidance of renal artery blood flow volume displayed on the electromagnetic flowmeter,different renal blood perfusion models were made with the micrometer constrictor.Then the color pixel area (CPA)and color value(CV) of PDI and the peak systolic velocity (PSV)and RI of renal segmental artery were calculated and analyzed.Results:The CPA、CV、PSV and RI tended to decrease with gradual reduction of the blood flow of renal artery and the decrease was especially significant when the renal blood flow reduced by 75%(P<0.05).The changes of PSV and RI were also significant(P<0.05).Conclusions:PDI can accurately reflect changes in the canine renal blood perfusions.%目的:应用计算机定量分析能量多普勒显像(PDI)显示犬肾不同程度血流灌注的准确性。方法:手术暴露犬右肾动脉,将电磁流量计和微米缩窄器固定其上,制备不同肾血流灌注模型。PDI显示肾血流图,计算机脱机分析肾血流图的彩色象素面积(CPA)和彩色亮度值(CV)。PWD测量肾段动脉的PSV、RI。结果:肾血流图CPA、CV及肾段动脉PSV、RI均与肾动脉血流量呈线性正相关(r=0.99)。以肾血流量减少50%和75%时,CPA减少明显(P<0.05和P<0.01)。而CV值仅在血流减少75%时下降明显(P<0.05)。PSV、RI均有明显变化(P<0.05)。结论:PDI可以较准确反映犬肾血流灌注的异常变化。

  10. Aid in the detection of myocardial perfusion abnormality utilizing SPECT atlas and images registration: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Padua, Rodrigo Donizete Santana de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Div. de Cardiologia]. E-mail: rodrigo_dsp@hcrp.fmrp.usp.br; Oliveira, Lucas Ferrari de [Universidade Federal de Pelotas (UFPel), RS (Brazil). Inst. de Fisica e Matematica. Dept. de Tecnologia da Informacao; Marques, Paulo Mazzoncini de Azevedo [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Groote, Jean-Jacques Georges Soares de [Instituto de Ensino Superior COC, Ribeirao Preto, SP (Brazil). Lab. of Artifical Intelligence and Applications; Castro, Adelson Antonio de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina; Ana, Lauro Wichert [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Simoes, Marcus Vinicius [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina. Divisao de Cardiologia

    2008-11-15

    To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observe. The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended. (author)

  11. Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion

    Science.gov (United States)

    Paltiel, H. J.; Padua, H. M.; Gargollo, P. C.; Cannon, G. M., Jr.; Alomari, A. I.; Yu, R.; Clement, G. T.

    2011-04-01

    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted 'gold standard'. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-15

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

  13. Lung cancer perfusion at multi-detector row CT: reproducibility of whole tumor quantitative measurements.

    Science.gov (United States)

    Ng, Quan-Sing; Goh, Vicky; Fichte, Heinz; Klotz, Ernst; Fernie, Pat; Saunders, Michele I; Hoskin, Peter J; Padhani, Anwar R

    2006-05-01

    Institutional review board approval and informed consent were obtained for this study. The aim of the study was to prospectively assess, in patients with lung cancer, the reproducibility of a quantitative whole tumor perfusion computed tomographic (CT) technique. Paired CT studies were performed in 10 patients (eight men, two women; mean age, 66 years) with lung cancer. Whole tumor permeability and blood volume were measured, and reproducibility was evaluated by using Bland-Altman statistics. Coefficient of variation of 9.49% for permeability and 26.31% for blood volume and inter- and intraobserver variability ranging between 3.30% and 6.34% indicate reliable assessment with this whole tumor technique.

  14. Electrocardiographic left ventricular hypertrophy without echocardiographic abnormalities evaluated by myocardial perfusion and fatty acid metabolic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Michihiro; Kurihara, Tadashi [Sumitomo Hospital, Osaka (Japan)

    2000-01-01

    The pathophysiologic process in patients with electrocardiographic left ventricular hypertrophy with ST, T changes but without echocardiographic abnormalities was investigated by myocardial perfusion imaging and fatty acid metabolic imaging. Exercise stress {sup 99m}Tc-methoxy-isobutyl isonitrile (MIBI) imaging and rest {sup 123}I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP) imaging were performed in 59 patients with electrocardiographic hypertrophy including 29 without apparent cause including hypertension and echocardiographic hypertrophy, and 30 with essential hypertension. Coronary angiography was performed in 6 patients without hypertension and 4 with hypertension and biopsy specimens were obtained from the left ventricular apex from 6 patients without hypertension. Myocardial perfusion and {sup 123}I-BMIPP images were classified into 3 types: normal, increased accumulation of the isotope at the left ventricular apex (high uptake) and defect. Transient perfusion abnormality and apical defect observed by {sup 123}I-BMIPP imaging were more frequent in patients without hypertension than in patients with hypertension (32% vs. 17%, p=0.04671 in perfusion; 62% vs. 30%, p=0.0236 in {sup 123}I-BMIPP). Eighteen normotensive patients with apical defect by {sup 123}I-BMIPP imaging included 3 of 10 patients with normal perfusion at exercise, 6 of 10 patients with high uptake and 9 of 9 patients with perfusion defect. The defect size revealed by {sup 123}I-BMIPP imaging was greater than that of the perfusion abnormality. Coronary stenoses were not observed and myocardial specimens showed myocardial disarray with hypertrophy. Moreover, 9 patients with hypertension and apical defects by {sup 123}I-BMIPP showed 3 different types of perfusion. Many patients without hypertension show a pathologic process similar to hypertrophic cardiomyopathy. Perfusion and {sup 123}I-BMIPP imaging are useful for the identification of these patients. (author)

  15. Imaging of Phosphorescence: A Novel Method for Measuring Oxygen Distribution in Perfused Tissue

    Science.gov (United States)

    Rumsey, William L.; Vanderkooi, Jane M.; Wilson, David F.

    1988-09-01

    The imaging of phosphorescence provides a method for monitoring oxygen distribution within the vascular system of intact tissues. Isolated rat livers were perfused through the portal vein with media containing palladium coproporphyrin, which phosphoresced and was used to image the liver at various perfusion rates. Because oxygen is a powerful quenching agent for phosphors, the transition from well-perfused liver to anoxia (no flow of oxygen) resulted in large increases of phosphorescence. During stepwise restoration of oxygen flow, the phosphorescence images showed marked heterogeneous patterns of tissue reoxygenation, which indicated that there were regional inequalities in oxygen delivery.

  16. Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of The Netherlands, Utrecht (Netherlands); El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Kroft, Lucia J. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Younis, Imad Al [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Reiber, Johan H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical imaging systems B.V., Leiden (Netherlands); Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

    2013-08-15

    Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 {+-} 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS {>=}2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p < 0.001, and OR 1.07, 95 % CI 1.00-1.45, p = 0.032, respectively) after correcting for clinical variables and visually assessed significant stenosis. The addition of quantitatively assessed significant stenosis ({chi} {sup 2} = 20.7) and lesion length ({chi} {sup 2} = 26.0) to the clinical variables and the visual assessment ({chi} {sup 2} = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have

  17. Low dose dynamic CT myocardial perfusion imaging using a statistical iterative reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Yinghua [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong [Department of Medical Physics and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Hacker, Timothy A.; Raval, Amish N. [Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Van Lysel, Michael S.; Speidel, Michael A., E-mail: speidel@wisc.edu [Department of Medical Physics and Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2014-07-15

    Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low (25 mA) dose dynamic CT myocardial perfusion scans with and without coronary occlusion. To delineate the affected myocardial territory, an N-13 ammonia PET perfusion scan was performed for each animal in each occlusion state. Filtered backprojection (FBP) reconstruction was first applied to all CT data sets. Then, a statistical iterative reconstruction (SIR) method was applied to data sets acquired at low dose. Image voxel noise was matched between the low dose SIR and high dose FBP reconstructions. CT perfusion maps were compared among the low dose FBP, low dose SIR and high dose FBP reconstructions. Numerical simulations of a dynamic CT scan at high and low dose (20:1 ratio) were performed to quantitatively evaluate SIR and FBP performance in terms of flow map accuracy, precision, dose efficiency, and spatial resolution. Results: Forin vivo studies, the 500 mA FBP maps gave −88.4%, −96.0%, −76.7%, and −65.8% flow change in the occluded anterior region compared to the open-coronary scans (four animals). The percent changes in the 25 mA SIR maps were in good agreement, measuring −94.7%, −81.6%, −84.0%, and −72.2%. The 25 mA FBP maps gave unreliable flow measurements due to streaks caused by photon starvation (percent changes of +137.4%, +71.0%, −11.8%, and −3.5%). Agreement between 25 mA SIR and 500 mA FBP global flow was −9.7%, 8.8%, −3.1%, and 26.4%. The average variability of flow measurements in a nonoccluded region was 16.3%, 24.1%, and 937

  18. The scintigraphic appearance of childhood moyamoya disease on cerebral perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.H. [Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA (United States)]|[University of Southern California School of Medicine, Los Angeles (United States); Khonsary, A. [Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA (United States)]|[University of Southern California School of Medicine, Los Angeles (United States); Raffel, C. [Department of Surgery, Childrens Hospital Los Angeles (United States)]|[University of Southern California School of Medicine, Los Angeles (United States)

    1996-12-01

    Objective. This study was performed to evaluate the role of single photon emission computed tomography (SPECT) perfusion imaging in the evaluation of patients with moyamoya disease. Materials and methods. Five patients (four female, one male) were studied utilizing iodine-123 iodoamphetamine or technetium-99m hexamethylpropyleneamine oxime SPECT. The data were reconstructed into axial, coronal and sagittal sections for review, and compared with CT, MR and/or angiographic images. Results. All five patients had significant perfusion defects. These areas of vascular compromise were seen to cross normal vascular territories, and were greater in number and extent than seen on anatomic sectional imaging. Conclusion. Patients with moyamoya disease have a recognizable pattern of scintigraphic perfusion deficits which should be identified by pediatric imaging physicians. SPECT perfusion studies should be performed in conjunction with other imaging modalities (CT, MR or angiography). (orig.). With 3 figs.

  19. The impact of hypertension on diastolic left ventricular function, evaluated by quantitative ECG-gated myocardial perfusion SPECT

    Directory of Open Access Journals (Sweden)

    Mohamed H.M. Sayed

    2015-09-01

    Conclusions: Quantitative ECG-gated Tc-99m tetrofosmin SPECT reveals that hypertensive patients with preserved global LV systolic function may have significant changes in diastolic LV function. Gated myocardial perfusion SPECT reports are always lacking in these changes in diastolic function. We recommend inclusion of such changes in diastolic function in gated myocardial perfusion SPECT reports that can help in proper management of hypertensive patients.

  20. 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

  1. 彩色多普勒血流显像结合定量分析技术评价肾血流灌注的临床研究%Clinical study on renal flow perfusion using color Doppler flow imaging combined with quantitative analysis technique

    Institute of Scientific and Technical Information of China (English)

    李薇玢; 林铤; 张艳容; 吕清; 王新房; 谢明星; 项飞翔; 陈玉媛; 刘莹莹; 郭美荣

    2009-01-01

    Objective To explore the clinical value of color Doppler flow imaging(CDFI) combined with quantitative analysis technique to evaluate renal flow perflusion. Methods Twenty patients with different renal diseases matched with healthy control subjects were examined with Philips iU22 CDFI system. CDFI system and Qlab quantitative technique were used to measure renal restrictive index(RI), vascularization index(VI), flow index(FI), vascularization-flow index (VFI). The patients all received renal single-photon emission computed tomography (SPECT) examination. Results The RI of 32 kidney with lower flow perfusion in SPECT were higher than in the contol group (P <0.01). VI,FI, VFI were lower than those in control(VI, VFI, P <0.01 ;FI, P <0.05). Conelusious The renal blood flow perfusion of patients with renal diseases are lower than that of healthy people. It has high clinical value using CDFI combined with quantitative analysis technique to evaluate the renal perfusion of the patients with renal diseases.%目的 探讨彩色多普勒血流显像结合血流定量分析技术评价肾血流灌注的临床意义.方法 采用Philips iU22彩色多普勒血流显像结合血流定量分析技术分别测量20例正常对照者和20例肾疾病患者的肾叶间动脉、小叶间动脉阻力指数(RI)、血管指数(VI)、血流指数(FI)、血管-血流指数(VFI),并进行比较分析.所有肾疾病患者均于彩色多普勒显像前后进行放射性核素肾动态扫描.结果 20例肾疾病患者单光子发射计算机断层显像检查(SPECT)显示血流灌注减少的32只肾叶间动脉、小叶间动脉RI值明显高于正常对照组(P<0.01),VI、FI、VFI值均明显低于正常对照组(VI,VFI,P<0.01;FI,P<0.05).结论 肾疾病患者的肾血流灌注显著低于正常对照组,利用彩色多普勒血流显像结合血流定量分析技术可以无创性定量评价肾血流灌注.

  2. An initial study on the feasibility of diagnosing myocardial ischemia with CT first-pass myocardial perfusion imaging at rest

    Institute of Scientific and Technical Information of China (English)

    汪奇

    2013-01-01

    Objective To assess the feasibility and accuracy of CT first-pass myocardial perfusion imaging(CT first-pass MPI)at rest for diagnosis of myocardial ischemia.Results of adenosine-induced myocardial perfusion scintigraphy(MPS)

  3. Quantitative analysis of qualitative images

    Science.gov (United States)

    Hockney, David; Falco, Charles M.

    2005-03-01

    We show optical evidence that demonstrates artists as early as Jan van Eyck and Robert Campin (c1425) used optical projections as aids for producing their paintings. We also have found optical evidence within works by later artists, including Bermejo (c1475), Lotto (c1525), Caravaggio (c1600), de la Tour (c1650), Chardin (c1750) and Ingres (c1825), demonstrating a continuum in the use of optical projections by artists, along with an evolution in the sophistication of that use. However, even for paintings where we have been able to extract unambiguous, quantitative evidence of the direct use of optical projections for producing certain of the features, this does not mean that paintings are effectively photographs. Because the hand and mind of the artist are intimately involved in the creation process, understanding these complex images requires more than can be obtained from only applying the equations of geometrical optics.

  4. GPC and quantitative phase imaging

    Science.gov (United States)

    Palima, Darwin; Bañas, Andrew Rafael; Villangca, Mark Jayson; Glückstad, Jesper

    2016-03-01

    Generalized Phase Contrast (GPC) is a light efficient method for generating speckle-free contiguous optical distributions using binary-only or analog phase levels. It has been used in applications such as optical trapping and manipulation, active microscopy, structured illumination, optical security, parallel laser marking and labelling and recently in contemporary biophotonics applications such as for adaptive and parallel two-photon optogenetics and neurophotonics. We will present our most recent GPC developments geared towards these applications. We first show a very compact static light shaper followed by the potential of GPC for biomedical and multispectral applications where we experimentally demonstrate the active light shaping of a supercontinuum laser over most of the visible wavelength range. Finally, we discuss how GPC can be advantageously applied for Quantitative Phase Imaging (QPI).

  5. Quantitative imaging with fluorescent biosensors.

    Science.gov (United States)

    Okumoto, Sakiko; Jones, Alexander; Frommer, Wolf B

    2012-01-01

    Molecular activities are highly dynamic and can occur locally in subcellular domains or compartments. Neighboring cells in the same tissue can exist in different states. Therefore, quantitative information on the cellular and subcellular dynamics of ions, signaling molecules, and metabolites is critical for functional understanding of organisms. Mass spectrometry is generally used for monitoring ions and metabolites; however, its temporal and spatial resolution are limited. Fluorescent proteins have revolutionized many areas of biology-e.g., fluorescent proteins can report on gene expression or protein localization in real time-yet promoter-based reporters are often slow to report physiologically relevant changes such as calcium oscillations. Therefore, novel tools are required that can be deployed in specific cells and targeted to subcellular compartments in order to quantify target molecule dynamics directly. We require tools that can measure enzyme activities, protein dynamics, and biophysical processes (e.g., membrane potential or molecular tension) with subcellular resolution. Today, we have an extensive suite of tools at our disposal to address these challenges, including translocation sensors, fluorescence-intensity sensors, and Förster resonance energy transfer sensors. This review summarizes sensor design principles, provides a database of sensors for more than 70 different analytes/processes, and gives examples of applications in quantitative live cell imaging.

  6. Regularized image reconstruction algorithms for dual-isotope myocardial perfusion SPECT (MPS) imaging using a cross-tracer prior.

    Science.gov (United States)

    He, Xin; Cheng, Lishui; Fessler, Jeffrey A; Frey, Eric C

    2011-06-01

    In simultaneous dual-isotope myocardial perfusion SPECT (MPS) imaging, data are simultaneously acquired to determine the distributions of two radioactive isotopes. The goal of this work was to develop penalized maximum likelihood (PML) algorithms for a novel cross-tracer prior that exploits the fact that the two images reconstructed from simultaneous dual-isotope MPS projection data are perfectly registered in space. We first formulated the simultaneous dual-isotope MPS reconstruction problem as a joint estimation problem. A cross-tracer prior that couples voxel values on both images was then proposed. We developed an iterative algorithm to reconstruct the MPS images that converges to the maximum a posteriori solution for this prior based on separable surrogate functions. To accelerate the convergence, we developed a fast algorithm for the cross-tracer prior based on the complete data OS-EM (COSEM) framework. The proposed algorithm was compared qualitatively and quantitatively to a single-tracer version of the prior that did not include the cross-tracer term. Quantitative evaluations included comparisons of mean and standard deviation images as well as assessment of image fidelity using the mean square error. We also evaluated the cross tracer prior using a three-class observer study with respect to the three-class MPS diagnostic task, i.e., classifying patients as having either no defect, reversible defect, or fixed defects. For this study, a comparison with conventional ordered subsets-expectation maximization (OS-EM) reconstruction with postfiltering was performed. The comparisons to the single-tracer prior demonstrated similar resolution for areas of the image with large intensity changes and reduced noise in uniform regions. The cross-tracer prior was also superior to the single-tracer version in terms of restoring image fidelity. Results of the three-class observer study showed that the proposed cross-tracer prior and the convergent algorithms improved the

  7. Stress-first single photon emission computed myocardial perfusion imaging

    Science.gov (United States)

    Aquino, C I; Scarano, M; Squame, F; Casaburi, G; Nori, S L; Pace, L

    2016-01-01

    Background Myocardial perfusion imaging (MPI) with single photon emission tomography (SPET) is widely used in coronary artery disease evaluation. Recently major dosimetric concerns have arisen. The aim of this study was to evaluate if a pre-test scoring system could predict the results of stress SPET MPI, thus avoiding two radionuclide injections. Methods All consecutive patients (n=309) undergoing SPET MPI during the first 6 months of 2014 constituted the study group. The scoring system is based on these characteristics: age >65 years (1 point), diabetes (2 points), typical chest pain (2 points), congestive heart failure (3 points), abnormal ECG (4 points), male gender (4 points), and documented previous CAD (5 points). The patients were divided on the basis of the prediction score into 3 classes of risk for an abnormal stress-first protocol. Results An abnormal stress SPET MPI was present in 7/31 patients (23%) with a low risk score, in 24/90 (27%) with an intermediate score risk, and in 124/188 (66%) with an high score risk. ROC curve analysis showed good prediction of abnormal stress MPI. Conclusions Our results suggest an appropriate use of a pre-test clinical prediction formula of abnormal stress MPI in a routine clinical setting. PMID:27896227

  8. Prognostic value of dobutamine-atropine stress myocardial perfusion imaging in patients with diabetes

    NARCIS (Netherlands)

    A.F.L. Schinkel (Arend); A. Elhendy (Abdou); J.J. Bax (Jeroen); E.C. Vourvouri (Eleni); F. Sozzi (Fabiola); R. Valkema (Roelf); D. Poldermans (Don); J.R.T.C. Roelandt (Jos); R.T. van Domburg (Ron)

    2002-01-01

    textabstractOBJECTIVE: Exercise tolerance in patients with diabetes is frequently impaired due to noncardiac disease such as claudication and polyneuropathy. This study assesses the prognostic value of dobutamine stress myocardial perfusion imaging in patients with diabetes. RESEAR

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-01

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

  10. Evaluation of the ventilation-perfusion ratio in lung diseases by simultaneous anterior and posterior image acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Yasunobu; Narabayashi, Isamu; Sueyoshi, Kozo; Matsui, Ritsuo; Namba, Ryuichiro; Tabuchi, Kojiro (Osaka Medical Coll., Takatsuki (Japan))

    1994-11-01

    Ventilation and perfusion images were acquired during tidal breathing using [sup 81m]Kr gas and [sup 99m]Tc-MAA. Anterior and posterior functional images of V/Q and Q/V were simultaneously acquired in 34 subjects with various lung diseases and 6 healthy controls. Superimposed anterior and posterior images were constructed and histograms of the frequency distribution for ventilation, perfusion, and the V/Q ratio were displayed for both lungs as well as for the left and right lungs individually. Blood gas analysis and general lung function tests were also performed on the day before scintigraphy. A correlation between marked uneven distribution of V/Q and A-aDO[sub 2] was found. When the proportion of counts at V/Q<0.67 and/or V/Q>1.50 in the V/Q counts histogram was compared with A-aDO[sub 2], there was a significant positive correlation for anterior images (r=0.684, p<0.05), posterior images (r=0.654, p<0.05) and superimposed images (r=0.696, p<0.05). Superimposed images therefore showed the highest correlation. There was no correlation between the results of lung function testing and A-aDO[sub 2]. Coronal SPECT images were also obtained in 15 patients and compared with the superimposed anterior and posterior planar images. There was a good correlation (r=0.888, p<0.001) between both the imaging methods regarding the marked uneven distribution of V/Q. Simultaneous anterior and posterior planar image acquisition reduces the examining time, is simple, and is noninvasive. The present results also suggest that it is useful for quantitative evaluation of the ventilation-perfusion ratio. (author).

  11. Development of coronary vasospasm during adenosine-stress myocardial perfusion CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jeong Gu; Choi, Seong Hoon; Kang, Byeong Seong; Bang, Min Aeo; Kwon, Woon Jeong [Dept. of Radiology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan (Korea, Republic of)

    2015-06-15

    Adenosine is a short-acting coronary vasodilator, and it is widely used during pharmacological stress myocardial perfusion imaging. It has a well-established safety profile, and most of its side effects are known to be mild and transient. Until now, coronary vasospasm has been rarely reported as a side effect of adenosine during or after adenosine stress test. This study reports a case of coronary vasospasm which was documented on stress myocardial perfusion CT imaging during adenosine stress test.

  12. Magnetic resonance myocardial perfusion imaging-First experience at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Klumpp, B. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Diagnostic Radiology, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: bernhard.klumpp@med.uni-tuebingen.de; Hoevelborn, T. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Cardiology, Otfried-Mueller-Str. 10, 72076 Tuebingen (Germany)], E-mail: tobias.hoevelborn@gmx.de; Fenchel, M. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Diagnostic Radiology, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: michael.fenchel@med.uni-tuebingen.de; Stauder, N.I. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Diagnostic Radiology, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: norbert.stauder@stgag.ch; Kramer, U. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Diagnostic Radiology, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: ulrich.kramer@med.uni-tuebingen.de; May, A. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Cardiology, Otfried-Mueller-Str. 10, 72076 Tuebingen (Germany)], E-mail: andreas.may@med.uni-tuebingen.de; Gawaz, M.P. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Cardiology, Otfried-Mueller-Str. 10, 72076 Tuebingen (Germany)], E-mail: meinrad.gawaz@med.uni-tuebingen.de; Claussen, C.D. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Diagnostic Radiology, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: claus.claussen@med.uni-tuebingen.de; Miller, S. [Eberhard-Karls-University Tuebingen, University Hospital Tuebingen, Department of Diagnostic Radiology, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)], E-mail: stephan.miller@med.uni-tuebingen.de

    2009-01-15

    Objective: MR myocardial perfusion imaging (MRMPI) is an established technique for the evaluation of the hemodynamical relevance of coronary artery disease. Perfusion imaging at 3.0 T provides certain advantages compared to 1.5 T. Aim of this study was to evaluate myocardial MR perfusion imaging at 3.0 T. Materials and methods: Twelve patients with stable Angina pectoris and known or suspected coronary artery disease were examined at 3.0 T. Myocardial perfusion was assessed using a saturation recovery gradient echo 2D sequence (TR 1.9 ms, TE 1.0 ms, FA 12 deg.) with 0.05 mmol Gd-DTPA per kg body weight at stress during injection of 140 {mu}g adenosine/kg body weight/min and at rest in short axis orientation. Perfusion analysis was based on a least square fit of the signal/time curve (peak signal intensity, slope). Perfusion series were assessed by two independent observers. Reference for the presence of relevant coronary artery stenoses was invasive coronary angiography. Two experienced observers evaluated the coronary angiograms in biplane projections for the presence and grade of stenoses. Results were compared with the MR perfusion analysis. Results: All MR examinations could be safely performed and yielded high image quality. In eight patients stress-induced hypoperfusion was detected (stenosis >70% in coronary angiography). In four patients myocardial hypoperfusion was ruled out (stenosis <70%). The myocardial perfusion reserve index was significantly reduced in hypoperfused myocardium with 1.9 {+-} 1.6 compared to 2.5 {+-} 1.6 in regularly perfused myocardium (p < 0.05). In coronary angiography, eight patients were found to suffer from coronary artery disease, whereas in four patients coronary artery disease was ruled out. Conclusion: Our initial results show that MRMPI at 3.0 T provides reliably high-image quality and diagnostic accuracy.

  13. Non-uniform noise spatial distribution in CT myocardial perfusion and a potential solution: statistical image reconstruction

    Science.gov (United States)

    Thériault Lauzier, Pascal; Tang, Jie; Chen, Guang-Hong

    2012-03-01

    Myocardial perfusion scans are an important tool in the assessment of myocardial viability following an infarction. Cardiac perfusion analysis using CT datasets is limited by the presence of so-called partial scan artifacts. These artifacts are due to variations in beam hardening and scatter between different short-scan angular ranges. In this research, another angular range dependent effect is investigated: non-uniform noise spatial distribution. Images reconstructed using filtered backprojection (FBP) are subject to this effect. Statistical image reconstruction (SIR) is proposed as a potential solution. A numerical phantom with added Poisson noise was simulated and two swines were scanned in vivo to study the effect of FBP and SIR on the spatial uniformity of the noise distribution. It was demonstrated that images reconstructed using FBP often show variations in noise on the order of 50% between different time frames. This variation is mitigated to about 10% using SIR. The noise level is also reduced by a factor of 2 in SIR images. Finally, it is demonstrated that the measurement of quantitative perfusion metrics are generally more accurate when SIR is used instead of FBP.

  14. 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.)

  15. Double-echo perfusion-weighted MR imaging: basic concepts and application in brain tumors for the assessment of tumor blood volume and vascular permeability

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, Hidemasa [University of Fukui, Department of Radiology, Faculty of Medical Sciences, Fukui (Japan); Maeda, Masayuki [Mie University School of Medicine, Department of Radiology, Mie (Japan)

    2006-01-01

    Perfusion-weighted magnetic resonance (MR) imaging using contrast agents plays a key role in characterizing tumors of the brain. We have shown that double-echo perfusion-weighted MR imaging (DEPWI) is potentially useful in assessing brain tumors. Quantitative indices, such as tumor blood volume, are obtained using DEPWI, which allows correction of underestimation of tumor blood volume due to leakage of contrast agents from tumor vessels, in addition to simultaneous acquisition of tumor vessel permeability. This article describes basic concepts of DEPWI and demonstrates clinical applications in brain tumors. (orig.)

  16. Comparison of rest and adenosine stress quantitative and semi-quantitative myocardial perfusion using magnetic resonance in patients with ischemic heart disease.

    Science.gov (United States)

    Qayyum, Abbas A; Qayyum, Faiza; Larsson, Henrik B W; Kjaer, Andreas; Hasbak, Philip; Vejlstrup, Niels G; Kastrup, Jens

    The aim was to compare absolute quantified myocardial perfusion (MP) to semi-quantitative measurements of MP using MRI for detection of ischemia. Twenty-nine patients underwent rest and stress MP imaging obtained by 1.5T MRI and analyzed using own developed software and by commercial available software. Linear regression analysis demonstrated that absolute quantitative data correlated stronger to maxSI (rest: r=0.296, p=.193; stress: r=0.583, p=0.011; myocardial perfusion reserve (MPR): r=0.789, prest: r=0.420, p=0.058; stress: r=0.096, p=0.704; MPR: r=0.682, p=0.004; and Δ MBF: r=0.055, p=0.804). Absolute quantified MP was able to distinguish between ischemic and non-ischemic territories at rest (left anterior descending artery (LAD): 103.1±11.3mL/100g/min vs. 206.3±98.5mL/100g/min; p=0.001, right coronary artery (RCA): 124.1±45.2mL/100g/min vs. 241.3±81.7mL/100g/min; prest and borderline significant at stress (r=0.265, p=0.382 and r=0.601, p=0.050, respectively). Quantified MP may be useful in patients for detection of ischemia. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Quantitative renal perfusion measurements in a rat model of acute kidney injury at 3T: testing inter- and intramethodical significance of ASL and DCE-MRI.

    Directory of Open Access Journals (Sweden)

    Fabian Zimmer

    Full Text Available OBJECTIVES: To establish arterial spin labelling (ASL for quantitative renal perfusion measurements in a rat model at 3 Tesla and to test the diagnostic significance of ASL and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI in a model of acute kidney injury (AKI. MATERIAL AND METHODS: ASL and DCE-MRI were consecutively employed on six Lewis rats, five of which had a unilateral ischaemic AKI. All measurements in this study were performed on a 3 Tesla MR scanner using a FAIR True-FISP approach and a TWIST sequence for ASL and DCE-MRI, respectively. Perfusion maps were calculated for both methods and the cortical perfusion of healthy and diseased kidneys was inter- and intramethodically compared using a region-of-interest based analysis. RESULTS/SIGNIFICANCE: Both methods produce significantly different values for the healthy and the diseased kidneys (P<0.01. The mean difference was 147±47 ml/100 g/min and 141±46 ml/100 g/min for ASL and DCE-MRI, respectively. ASL measurements yielded a mean cortical perfusion of 416±124 ml/100 g/min for the healthy and 316±102 ml/100 g/min for the diseased kidneys. The DCE-MRI values were systematically higher and the mean cortical renal blood flow (RBF was found to be 542±85 ml/100 g/min (healthy and 407±119 ml/100 g/min (AKI. CONCLUSION: Both methods are equally able to detect abnormal perfusion in diseased (AKI kidneys. This shows that ASL is a capable alternative to DCE-MRI regarding the detection of abnormal renal blood flow. Regarding absolute perfusion values, nontrivial differences and variations remain when comparing the two methods.

  18. Clinical application of 3D arterial spin-labeled brain perfusion imaging for Alzheimer disease: comparison with brain perfusion SPECT.

    Science.gov (United States)

    Takahashi, H; Ishii, K; Hosokawa, C; Hyodo, T; Kashiwagi, N; Matsuki, M; Ashikaga, R; Murakami, T

    2014-05-01

    Alzheimer disease is the most common neurodegenerative disorder with dementia, and a practical and economic biomarker for diagnosis of Alzheimer disease is needed. Three-dimensional arterial spin-labeling, with its high signal-to-noise ratio, enables measurement of cerebral blood flow precisely without any extrinsic tracers. We evaluated the performance of 3D arterial spin-labeling compared with SPECT, and demonstrated the 3D arterial spin-labeled imaging characteristics in the diagnosis of Alzheimer disease. This study included 68 patients with clinically suspected Alzheimer disease who underwent both 3D arterial spin-labeling and SPECT imaging. Two readers independently assessed both images. Kendall W coefficients of concordance (K) were computed, and receiver operating characteristic analyses were performed for each reader. The differences between the images in regional perfusion distribution were evaluated by means of statistical parametric mapping, and the incidence of hypoperfusion of the cerebral watershed area, referred to as "borderzone sign" in the 3D arterial spin-labeled images, was determined. Readers showed K = 0.82/0.73 for SPECT/3D arterial spin-labeled imaging, and the respective areas under the receiver operating characteristic curve were 0.82/0.69 for reader 1 and 0.80/0.69 for reader 2. Statistical parametric mapping showed that the perisylvian and medial parieto-occipital perfusion in the arterial spin-labeled images was significantly higher than that in the SPECT images. Borderzone sign was observed on 3D arterial spin-labeling in 70% of patients misdiagnosed with Alzheimer disease. The diagnostic performance of 3D arterial spin-labeling and SPECT for Alzheimer disease was almost equivalent. Three-dimensional arterial spin-labeled imaging was more influenced by hemodynamic factors than was SPECT imaging. © 2014 by American Journal of Neuroradiology.

  19. Calf muscle perfusion as measured with magnetic resonance imaging to assess peripheral arterial disease.

    Science.gov (United States)

    Brunner, Gerd; Bismuth, Jean; Nambi, Vijay; Ballantyne, Christie M; Taylor, Addison A; Lumsden, Alan B; Morrisett, Joel D; Shah, Dipan J

    2016-11-01

    We hypothesized that skeletal muscle perfusion is impaired in peripheral arterial disease (PAD) patients compared to healthy controls and that perfusion patterns exhibit marked differences across five leg muscle compartments including the anterior muscle group (AM), lateral muscle group (LM), deep posterior muscle group (DM), soleus (SM), and the gastrocnemius muscle (GM). A total of 40 individuals (26 PAD patients and 14 healthy controls) underwent contrast-enhanced magnetic resonance imaging (CE-MRI) utilizing a reactive hyperemia protocol. Muscle perfusion maps were developed for AM, LM, DM, SM, and GM. Perfusion maps were analyzed over the course of 2 min, starting at local pre-contrast arrival, to study early-to-intermediate gadolinium enhancement. PAD patients had a higher fraction of hypointense voxels at pre-contrast arrival for all five muscle compartments compared with healthy controls (p perfusion is markedly reduced in PAD patients compared with healthy controls and shows heterogeneous patterns across calf muscle compartments.

  20. Accuracy and feasibility of dynamic contrast-enhanced 3D MR imaging in the assessment of lung perfusion: comparison with Tc-99 MAA perfusion scintigraphy.

    Science.gov (United States)

    Yilmaz, E; Akkoclu, A; Degirmenci, B; Cooper, R A; Sengun, B; Gulcu, A; Osma, E; Ucan, E S

    2005-08-01

    The aim of this study was to correlate findings of perfusion magnetic resonance imaging (MRI) and perfusion scintigraphy in cases where there was a suspicion of abnormal pulmonary vasculature, and to evaluate the usefulness of MRI in the detection of perfusion deficits of the lung. In all, 17 patients with suspected abnormality of the pulmonary vasculature underwent dynamic contrast-enhanced MRI. T1-weighted 3D fast-field echo pulse sequences were obtained (TR/TE 3.3/1.58 ms; flip angle 30 degrees; slice thickness 12 to 15 mm). The dynamic study was acquired in the coronal plane following administration of 0.1 mmol/kg gadopentetate dimeglumine. A total of 8 to 10 sections repeated 20 to 25 times at intervals of 1s were performed. Perfusion lung scintigraphy was carried out a maximum of 48 h before the MR examination in all cases. Two radiologists, who were blinded to the clinical data and results of other imaging methods, reviewed all coronal sections. MR perfusion images were independently assessed in terms of segmental or lobar perfusion defects in the 85 lobes of the 17 individuals, and the findings were compared with the results of scintigraphy. Of the 17 patients, 8 were found to have pulmonary emboli, 2 chronic obstructive pulmonary disease with emphysema, 2 bullous emphysema, 2 Takayasu arteritis and 1 had a hypoplastic pulmonary artery. Pulmonary perfusion was completely normal in 2 cases. In 35 lobes, perfusion defects were detected using both methods, in 4 with MR alone and in 9 only with scintigraphy. There was good agreement between MRI and scintigraphy findings (kappa=0.695). Pulmonary perfusion MRI is a new alternative to scintigraphy in the evaluation of pulmonary perfusion for various lung disorders. In addition, this technique allows measurement and quantification of pulmonary perfusion abnormalities.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

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

  2. The additive prognostic value of perfusion and functional data assessed by quantitative gated SPECT in women

    NARCIS (Netherlands)

    Y.G.C.J. America (Yves); J.J. Bax (Jeroen); H. Boersma (Eric); M. Stokkel (Marcel); E.E. van der Wall (Ernst)

    2009-01-01

    textabstractBackground: The aim of this study was to assess the prognostic value of technetium-99m tetrofosmin gated SPECT imaging in women using quantitative gated single photon emission computed tomography (SPECT) imaging. Methods: We followed 453 consecutive female patients. Average follow-up was

  3. Optimized Saturation Pulse Train for Human First-Pass Myocardial Perfusion Imaging at 7T

    Science.gov (United States)

    Tao, Yuehui; Hess, Aaron T; Keith, Graeme A; Rodgers, Christopher T; Liu, Alexander; Francis, Jane M; Neubauer, Stefan; Robson, Matthew D

    2015-01-01

    Purpose To investigate whether saturation using existing methods developed for 3T imaging is feasible for clinical perfusion imaging at 7T, and to propose a new design of saturation pulse train for first-pass myocardial perfusion imaging at 7T. Methods The new design of saturation pulse train consists of four hyperbolic-secant (HS8) radiofrequency pulses, whose peak amplitudes are optimized for a target range of static and transmit field variations and radiofrequency power deposition restrictions measured in the myocardium at 7T. The proposed method and existing methods were compared in simulation, phantom, and in vivo experiments. Results In healthy volunteer experiments without contrast agent, average saturation efficiency with the proposed method was 97.8%. This is superior to results from the three previously published methods at 86/95/90.8%. The first series of human first-pass myocardial perfusion images at 7T have been successfully acquired with the proposed method. Conclusion Existing saturation methods developed for 3T imaging are not optimal for perfusion imaging at 7T. The proposed new design of saturation pulse train can saturate effectively, and with this method first-pass myocardial perfusion imaging is feasible in humans at 7T. Magn Reson Med 73:1450–1456, 2015. © 2014 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. PMID:24753130

  4. TU-AB-204-01: Advances in C-Arm CBCT for Brain Perfusion Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G. [University of Wisconsin (United States)

    2015-06-15

    This symposium highlights advanced cone-beam CT (CBCT) technologies in four areas of emerging application in diagnostic imaging and image-guided interventions. Each area includes research that extends the spatial, temporal, and/or contrast resolution characteristics of CBCT beyond conventional limits through advances in scanner technology, acquisition protocols, and 3D image reconstruction techniques. Dr. G. Chen (University of Wisconsin) will present on the topic: Advances in C-arm CBCT for Brain Perfusion Imaging. Stroke is a leading cause of death and disability, and a fraction of people having an acute ischemic stroke are suitable candidates for endovascular therapy. Critical factors that affect both the likelihood of successful revascularization and good clinical outcome are: 1) the time between stroke onset and revascularization; and 2) the ability to distinguish patients who have a small volume of irreversibly injured brain (ischemic core) and a large volume of ischemic but salvageable brain (penumbra) from patients with a large ischemic core and little or no penumbra. Therefore, “time is brain” in the care of the stroke patients. C-arm CBCT systems widely available in angiography suites have the potential to generate non-contrast-enhanced CBCT images to exclude the presence of hemorrhage, time-resolved CBCT angiography to evaluate the site of occlusion and collaterals, and CBCT perfusion parametric images to assess the extent of the ischemic core and penumbra, thereby fulfilling the imaging requirements of a “one-stop-shop” in the angiography suite to reduce the time between onset and revascularization therapy. The challenges and opportunities to advance CBCT technology to fully enable the one-stop-shop C-arm CBCT platform for brain imaging will be discussed. Dr. R. Fahrig (Stanford University) will present on the topic: Advances in C-arm CBCT for Cardiac Interventions. With the goal of providing functional information during cardiac interventions

  5. Perfusion and ventilation filters for Fourier-decomposition MR lung imaging.

    Science.gov (United States)

    Wujcicki, Artur; Corteville, Dominique; Materka, Andrzej; Schad, Lothar R

    2015-03-01

    MR imaging without the use of contrast agents has recently been used for creating perfusion and ventilation functional lung images. The technique incorporates frequency- or wavelet-domain filters to separate the MR signal components. This paper presents a new, subject-adaptive algorithm for perfusion and ventilation filters design. The proposed algorithm uses a lung signal model for separation of the signal components in the frequency domain. Non-stationary lung signals are handled by a short time Fourier transform. This method was applied to sets of 192 and 90 co-registered non-contrast MR lung images measured for five healthy subjects at the rate of 3,33 images per second, using different slice thicknesses. In each case, the resulted perfusion and ventilation images showed a smaller amount of mutual information, when compared to those obtained using the known lowpass/highpass filter approach.

  6. Perfusion and ventilation filters for Fourier-decomposition MR lung imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wujcicki, Artur; Materka, Andrzej [Lodz University of Technology (Poland). Inst. of Electronics; Corteville, Dominique; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine

    2015-05-01

    MR imaging without the use of contrast agents has recently been used for creating perfusion and ventilation functional lung images. The technique incorporates frequency- or wavelet-domain filters to separate the MR signal components. This paper presents a new, subject-adaptive algorithm for perfusion and ventilation filters design. The proposed algorithm uses a lung signal model for separation of the signal components in the frequency domain. Non-stationary lung signals are handled by a short time Fourier transform. This method was applied to sets of 192 and 90 co-registered non-contrast MR lung images measured for five healthy subjects at the rate of 3,33 images per second, using different slice thicknesses. In each case, the resulted perfusion and ventilation images showed a smaller amount of mutual information, when compared to those obtained using the known lowpass/highpass filter approach.

  7. Direct myocardial perfusion imaging in valvular heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Soto, R.C.; Durante, M.L.; Villacorta, E.V.; Torres, J.F.; Monzon, O.P.

    1981-02-01

    Twenty two patients with rheumatic valvular heart disease - 21 having a history of heart failure - were studied using direct coronary injection of /sup 99m/Tc labelled MAA particles during the course of hemodynamic and arteriographic studies. Myocardial perfusion deficit patterns have been shown to be consistent or indicative of either patchy, regional or gross ischemia. In patients with history of documented heart failure 90% (18 cases) had ischemic perfusion deficit in the involved ventricle. We conclude that diminished myocardial blood flow is an important mechanism contributing to the development of heart failure.

  8. Non-ischemic perfusion defects due to delayed arrival of contrast material on stress perfusion cardiac magnetic resonance imaging after coronary artery bypass graft surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeo Koon; Park, Eun Ah; Park, Sang Joon; Cheon, Gi Jeong; Lee, Whal; Chung, Jin Wook; Park, Jae Hyung [Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-04-15

    Herein we report about the adenosine stress perfusion MR imaging findings of a 50-year-old man who exhibited two different perfusion defects resulting from two different mechanisms after a coronary artery bypass surgery. An invasive coronary angiography confirmed that one perfusion defect at the mid-anterior wall resulted from an ischemia due to graft stenosis. However, no stenosis was detected on the graft responsible for the mid-inferior wall showing the other perfusion defect. It was assumed that the perfusion defect at the mid-inferior wall resulted from delayed perfusion owing to the long pathway of the bypass graft. The semiquantitative analysis of corrected signal-time curves supported our speculation, demonstrating that the rest-to-stress ratio index of the maximal slope of the myocardial territory in question was similar to those of normal myocardium, whereas that of myocardium with the stenotic graft showed a typical ischemic pattern. A delayed perfusion during long graft pathway in a post-bypass graft patient can mimick a true perfusion defect on myocardial stress MR imaging. Radiologists should be aware of this knowledge to avoid misinterpretation of graft and myocardial status in post bypass surgery patients.

  9. Contrast enhanced ultrasound with quantitative perfusion analysis for objective characterization of pancreatic ductal adenocarcinoma: A feasibility study.

    Science.gov (United States)

    D'Onofrio, Mirko; Canestrini, Stefano; Crosara, Stefano; De Robertis, Riccardo; Pozzi Mucelli, Roberto

    2014-03-28

    The aim of this study was to determine whether contrast enhanced ultrasound (CEUS) quantitative perfusion analysis allows an objective characterization of ductal adenocarcinoma (ADK) of the pancreas. Patients with pancreatic ADK underwent CEUS. All examinations were performed on an Acuson S2000 system (Siemens, Erlangen, Germany) after the iv administration of 2.4 mL contrast agent (SonoVue(®), Bracco, Milan, Italy). All lesions were pathologically proved. An operator manually drew different regions of interest within the tumor and the adjacent parenchyma to allow the quantitative perfusion analysis. The mean values of peak of enhancement, time to peak and ascending curve were calculated and compared using the Student's t test. The quantitative perfusion analysis was possible in all lesions. The mean values of the peak of enhancement, time to peak and ascending curve were 17.19%, 7.97 s and 159.52% s within the tumor and 33.57%, 8.89 s and 355.29% s within the adjacent parenchyma. The peak of enhancement and the ascending curve values were significantly different within the tumor and the adjacent parenchyma. Thus, CEUS allows the quantitative perfusion analysis of pancreatic ductal adenocarcinoma.

  10. Magnetic resonance imaging of luxury perfusion of the optic nerve head in anterior ischemic optic neuropathy.

    Science.gov (United States)

    Yovel, Oren S; Katz, Miriam; Leiba, Hana

    2012-09-01

    A 49-year-old woman with painless reduction in visual acuity in her left eye was found to have nonarteritic anterior ischemic optic neuropathy (NAION). Fluorescein angiography revealed optic disc capillary leakage consistent with "luxury perfusion." Contrast-enhanced FLAIR magnetic resonance imaging (MRI) showed marked enhancement of the left optic disc. Resolution of the optic disc edema and the MRI abnormalities followed a similar time course. This report appears unique in documenting the MRI findings of luxury perfusion in NAION.

  11. Effect of administered radioactive dose level on image quality of brain perfusion imaging with 99mTc-HMPAO

    Directory of Open Access Journals (Sweden)

    I.Armeniakos

    2008-01-01

    Full Text Available Brain perfusion imaging by means of 99mTc-labeled hexamethyl propylene amine oxime (HMPAO is a well-established Nuclear Medicine diagnostic procedure. The administered dose range recommended by the supplying company and reported in bibliography is rather wide (approximately 9.5-27 mCi. This fact necessitates further quantitative analysis of the technique, so as to minimise patient absorbed dose without compromising the examination diagnostic value. In this study, a quantitative evaluation of the radiopharmaceutical performance for different values of administered dose (10, 15, 20 mCi was carried out. Subsequently, a generic image quality index was correlated with the administered dose, to produce an overall performance indicator. Through this cost-to-benefit type analysis, the necessity of administration of higher radioactive dose levels in order to perform the specific diagnostic procedure was examined.Materials & methods: The study was based on a sample of 78 patients (56 administered with 10 mCi, 10 with 15 mCi and 12 with 20 mCi. Some patients were classified as normal, while others presented various forms of pathology. Evaluation of image quality was based on contrast, noise and contrast-to-noise ratio indicators, denoted CI, NI and CNR respectively. Calculation of all indicators was based on wavelet transform. An overall performance indicator (denoted PI, produced by the ratio of CNR by administered dose, was also calculated.Results: Calculation of skewness parameter revealed the normality of CI, NI and non-normality of CNR, PI populations. Application of appropriate statistical tests (analysis of variance for normal and Kruskal-Wallis test for non-normal populations showed that there is a statistically significant difference in CI (p0.05 values. Application of Tukey test for normal populations CI, NI led to the conclusion that CI(10 mCi = CI(20 mCiNI(20 mCi, while NI(15 mCi can not be characterised. Finally, application of non

  12. A comparison of resting images from two myocardial perfusion tracers

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostopoulos, C. [Royal Brompton Hospital, London (United Kingdom); Laney, R. [Royal Brompton Hospital, London (United Kingdom); Pennell, D. [National Heart and Lung Inst., London (United Kingdom); Proukakis, H. [University of Athens Medical School (Greece); Underwood, R. [National Heart and Lung Inst., London (United Kingdom)

    1995-09-01

    We have compared stress-redistribution and delayed rest thallium-201 with rest technetium-99m methoxyisobutylisonitrile (MIBI) tomograms in order to compare the tracers for the assessment of myocardial viability and to validate a rapid protocol combining the two tracers. We studied 30 consecutive patients with known or suspected coronary artery disease [group 1: 16 with normal left ventricular function, mean left ventricular ejection fraction (LVEF) 55%, SD 6%; group 2: 14 with abnormal function, mean LVEF 28%, SD 8%]. {sup 201}Tl was injected during infusion of adenosine followed by acquisition of conventional stress and redistribution tomograms. On a separate day, {sup 201}Tl was injected at rest with imaging 4 h later. {sup 99m}Tc-MIBI was then given at rest and imaging was performed. Three images were compared: redistribution {sup 201}Tl, rest {sup 201}Tl, and rest {sup 99m}Tc-MIBI. Tracer activity was classified visually and quantitatively in nine segments and segments with>50% activity were defined as containing clinically significant viable myocardium. Mean global tracer uptake as a percentage of maximum was similar in group 1 (rest {sup 201}Tl 69%{+-}12%, redistribution {sup 201}Tl 69%{+-}15%, rest {sup 99m}Tc-MIBI 70%{+-}13%), but in group 2 mean tracer uptake was significantly greater in the rest {sup 201}Tl images (59%{+-}16%) than in redistribution {sup 201}Tl images (53%{+-}17%) or rest {sup 99m}Tc-MIBI images (53%{+-}19%). Overall agreement for regional uptake score was excellent ({kappa} from 0.79 to 0.84), although there were a significant number of segments with less uptake shown by redistribution {sup 201}Tl and by rest {sup 99m}Tc-MIBI than by rest {sup 201}Tl in group 2. The number of segments with significant viable myocardium in group 1 was very similar between the three images but in group 2 rest {sup 201}Tl identified significantly more segments as viable than the other images. (orig./MG) (orig.). With 1 fig., 7 tabs.

  13. Study on 64-layer Spiral Computed Tomography Perfusion Imaging in Patients with Fatty Liver

    Institute of Scientific and Technical Information of China (English)

    RAO Xiao-hui; SU Qi; CAI Lei; QIN Jia-sheng; CAI Li-quan; HONG He; WANG Kang-hua; AI Zhi-guo; ZHANG Sheng

    2014-01-01

    Objective:To analyze the changes of hemodynamics of patients with fatty liver by detecting their blood perfusion parameter changes with Philips Brilliance 64-layer spiral computed tomography (CT) perfusion technique. Methods: A total of 74 patients undergoing 64-layer spiral CT perfusion imaging were selected as study objects, in which 39 were with fatty liver and the other 35 were healthy people. The parameters of liver blood perfusion were observed. Results: Hepatic arterial perfusion (Art.Perf), portal perfusion (Port.Perf) and total perfusion (Total.Perf) values as well as hepatic perfusion index (HPI) were (18.4±4.1), (71.5±14.2) and (93.2±6.7) mL/100 g·min as well as (25.15±5.22)% in control group, in which the Art.Perf, Port.Perf and Total.Perf were in close association with the severity of fatty liver and of great significance. Art.Perf of patients with mild, moderate and severe fatty liver was (15.4±4.0), (7.3±9.6) and (4.1±1.3) mL/100 g·min, Port.Perf was (56.5±10.7), (48.6±6.8) and (37.0±4.1) mL/100 g·min and Total.Perf was (71.3±5.7), (55.7±5.8) and (40.2±5.0) mL/100 g·min, respectively. However, HPI could not be considered as the evaluation index for the severity of fatty liver. Conclusion:CT perfusion imaging of liver can relfect blood changes of patients with fatty liver, which can be used to evaluate their blood-supply condition, thus providing more diagnostic evidences for the clinic.

  14. Study on 64-layer Spiral Computed Tomography Perfusion Imaging in Patients with Fatty Liver

    Directory of Open Access Journals (Sweden)

    RAO Xiao-hui

    2014-12-01

    Full Text Available Objective: To analyze the changes of hemodynamics of patients with fatty liver by detecting their blood perfusion parameter changes with Philips Brilliance 64-layer spiral computed tomography (CT perfusion technique. Methods: A total of 74 patients undergoing 64-layer spiral CT perfusion imaging were selected as study objects, in which 39 were with fatty liver and the other 35 were healthy people. The parameters of liver blood perfusion were observed. Results: Hepatic arterial perfusion (Art.Perf, portal perfusion (Port.Perf and total perfusion (Total.Perf values as well as hepatic perfusion index (HPI were (18.4±4.1, (71.5±14.2 and (93.2±6.7 mL/100 g·min as well as (25.15±5.22% in control group, in which the Art.Perf, Port.Perf and Total.Perf were in close association with the severity of fatty liver and of great significance. Art.Perf of patients with mild, moderate and severe fatty liver was (15.4±4.0, (7.3±9.6 and (4.1±1.3 mL/100 g·min, Port.Perf was (56.5±10.7, (48.6±6.8 and (37.0±4.1 mL/100 g·min and Total.Perf was (71.3±5.7, (55.7±5.8 and (40.2±5.0 mL/100 g·min, respectively. However, HPI could not be considered as the evaluation index for the severity of fatty liver. Conclusion: CT perfusion imaging of liver can reflect blood changes of patients with fatty liver, which can be used to evaluate their blood-supply condition, thus providing more diagnostic evidences for the clinic.

  15. 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.

  16. 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.

  17. Quantitative blood flow velocity imaging using laser speckle flowmetry

    Science.gov (United States)

    Nadort, Annemarie; Kalkman, Koen; van Leeuwen, Ton G.; Faber, Dirk J.

    2016-04-01

    Laser speckle flowmetry suffers from a debated quantification of the inverse relation between decorrelation time (τc) and blood flow velocity (V), i.e. 1/τc = αV. Using a modified microcirculation imager (integrated sidestream dark field - laser speckle contrast imaging [SDF-LSCI]), we experimentally investigate on the influence of the optical properties of scatterers on α in vitro and in vivo. We found a good agreement to theoretical predictions within certain limits for scatterer size and multiple scattering. We present a practical model-based scaling factor to correct for multiple scattering in microcirculatory vessels. Our results show that SDF-LSCI offers a quantitative measure of flow velocity in addition to vessel morphology, enabling the quantification of the clinically relevant blood flow, velocity and tissue perfusion.

  18. Intra-voxel incoherent motion perfusion MR Imaging: a wake-up call

    Energy Technology Data Exchange (ETDEWEB)

    Le Bihan, D. [CEA Saclay, DSV, I2BM, F-91191 Gif Sur Yvette (France)

    2008-07-01

    This work gives the results of several studies made by different authors on IVIM MR Imaging. It appears that there are genuine potential applications for IVIM MR imaging. Perfusion is a very important surrogate marker of many physiologic or pathologic processes. MR imaging perfusion parameters can be obtained by using gadolinium-based contrast agents, either injected as a bolus (to determine blood flow, transit times, etc) or in a steady-state mode (to address blood volume, vessel permeability, etc). With the rising concern of nephrogenic systemic fibrosis, some patients cannot be examined with such an approach. IVIM MR imaging may then appear as an interesting alternative to provide crucial clues on perfusion in tissues, such as the kidneys, the liver, or even the placenta during pregnancy. (O.M.)

  19. Radiation dose reduction in perfusion CT imaging of the brain: A review of the literature.

    Science.gov (United States)

    Othman, Ahmed E; Afat, Saif; Brockmann, Marc A; Nikoubashman, Omid; Brockmann, Carolin; Nikolaou, Konstantin; Wiesmann, Martin

    2016-02-01

    Perfusion CT (PCT) of the brain is widely used in the settings of acute ischemic stroke and vasospasm monitoring. The high radiation dose associated with PCT is a central topic and has been a focus of interest for many researchers. Many studies have examined the effect of radiation dose reduction in PCT using different approaches. Reduction of tube current and tube voltage can be efficient and lead to a remarkable reduction of effective radiation dose while preserving acceptable image quality. The use of novel noise reduction techniques such as iterative reconstruction or spatiotemporal smoothing can produce sufficient image quality from low-dose perfusion protocols. Reduction of sampling frequency of perfusion images has only little potential to reduce radiation dose. In the present article we aimed to summarize the available data on radiation dose reduction in PCT imaging of the brain.

  20. Resting state functional connectivity in perfusion imaging: correlation maps with BOLD connectivity and resting state perfusion.

    Directory of Open Access Journals (Sweden)

    Roberto Viviani

    Full Text Available Functional connectivity is a property of the resting state that may provide biomarkers of brain function and individual differences. Classically, connectivity is estimated as the temporal correlation of spontaneous fluctuations of BOLD signal. We investigated differences in connectivity estimated from the BOLD and CBF signal present in volumes acquired with arterial spin labeling technique in a large sample (N = 265 of healthy individuals. Positive connectivity was observable in both BOLD and CBF signal, and was present in the CBF signal also at frequencies lower than 0.009 Hz, here investigated for the first time. Negative connectivity was more variable. The validity of positive connectivity was confirmed by the existence of correlation across individuals in its intensity estimated from the BOLD and CBF signal. In contrast, there was little or no correlation across individuals between intensity of connectivity and mean perfusion levels, suggesting that these two biomarkers correspond to distinct sources of individual differences.

  1. 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...... 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 (13)N-ammonia PET were fitted by a two-compartment perfusion model. RESULTS: Mean perfusion values (+/-SD) derived from the MRI...... as a quantitative marker for myocardial perfusion in healthy humans....

  2. Quantitative Study of Thermal Disturbances Due to Nonuniformly Perfused Tumors in Peripheral Regions of Women's Breast.

    Science.gov (United States)

    Makrariya, Akshara; Adlakha, Neeru

    2017-01-01

    Mathematical modeling of biothermal processes is widely used to enhance the quantitative understanding of thermoregulation system of human body organs. This quantitative knowledge of thermal information of various human body organs can be used for developing clinical applications. In the past, investigators have studied thermal distribution in hemisphere-shaped human breast in the presence of sphere-shaped tumor. The shape and size of the breast as well as tumor may also affect thermal distribution which can have serious implications in thermography. In this article, a model of thermal disturbances in peripheral regions of ellipsoid-shaped human breast involving ellipse-shaped nonuniformly perfused tumor has been developed for a 2-dimensional steady-state case. The modeling study will provide biomedical scientists vital insights of thermal changes occurring due to the shape and size of breast and tumor which can influence the development of protocols of thermography for diagnosis of tumors in women's breast. We have incorporated the significant parameters such as blood flow, metabolic activity, and thermal conductivity in the thermal model for normal and malignant tissues. The controlled metabolic activity has been incorporated for normal tissues, and uncontrolled metabolic activity has been incorporated for tumor regions. The peripheral regions of breast are divided into 3 major layers, namely, epidermis, dermis, and subdermal tissues. An ellipse-shaped nonuniformly perfused tumor is assumed to be present in dermal layers. The nonuniformly perfused tumor is divided into 2 natural components, namely, the necrotic core and tumor periphery. The outer surface of the breast is assumed to be exposed to the environment, and the heat loss takes place by conduction, convection, radiation, and evaporation. The finite element approach is used to obtain the solution. The numerical results have been used to study the effect of shape and size of tumor on temperature

  3. Hepatic CT perfusion measurements: A feasibility study for radiation dose reduction using new image reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Negi, Noriyuki, E-mail: noriyuki@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Yoshikawa, Takeshi, E-mail: yoshikawa0816@aol.com [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Somiya, Yuichiro, E-mail: somiya13@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Sekitani, Toshinori, E-mail: atieinks-toshi@nifty.com [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Sugihara, Naoki, E-mail: naoki.sugihara@toshiba.co.jp [Toshiba Medical Systems Co., 1385 Shimoishigami, Otawara 324-0036 (Japan); Koyama, Hisanobu, E-mail: hkoyama@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kanda, Tomonori, E-mail: k_a@hotmail.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kanata, Naoki, E-mail: takikina12345@yahoo.co.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Murakami, Tohru, E-mail: mura@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Kawamitsu, Hideaki, E-mail: kawamitu@med.kobe-u.ac.jp [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan); Sugimura, Kazuro, E-mail: sugimura@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuoku, Kobe 650-0017 (Japan)

    2012-11-15

    Objectives: To assess the effects of image reconstruction method on hepatic CT perfusion (CTP) values using two CT protocols with different radiation doses. Materials and methods: Sixty patients underwent hepatic CTP and were randomly divided into two groups. Tube currents of 210 or 250 mA were used for the standard dose group and 120 or 140 mA for the low dose group. The higher currents were selected for large patients. Demographic features of the groups were compared. CT images were reconstructed by using filtered back projection (FBP), image filter (quantum de-noising, QDS), and adaptive iterative dose reduction (AIDR). Hepatic arterial and portal perfusion (HAP and HPP, ml/min/100 ml) and arterial perfusion fraction (APF, %) were calculated using the dual-input maximum slope method. ROIs were placed on each hepatic segment. Perfusion and Hounsfield unit (HU) values, and image noises (standard deviations of HU value, SD) were measured and compared between the groups and among the methods. Results: There were no significant differences in the demographic features of the groups, nor were there any significant differences in mean perfusion and HU values for either the groups or the image reconstruction methods. Mean SDs of each of the image reconstruction methods were significantly lower (p < 0.0001) for the standard dose group than the low dose group, while mean SDs for AIDR were significantly lower than those for FBP for both groups (p = 0.0006 and 0.013). Radiation dose reductions were approximately 45%. Conclusions: Image reconstruction method did not affect hepatic perfusion values calculated by dual-input maximum slope method with or without radiation dose reductions. AIDR significantly reduced images noises.

  4. Evaluation of static and dynamic perfusion cardiac computed tomography for quantitation and classification tasks.

    Science.gov (United States)

    Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R; La Riviere, Patrick J; Alessio, Adam M

    2016-04-01

    Cardiac computed tomography (CT) acquisitions for perfusion assessment can be performed in a dynamic or static mode. Either method may be used for a variety of clinical tasks, including (1) stratifying patients into categories of ischemia and (2) using a quantitative myocardial blood flow (MBF) estimate to evaluate disease severity. In this simulation study, we compare method performance on these classification and quantification tasks for matched radiation dose levels and for different flow states, patient sizes, and injected contrast levels. Under conditions simulated, the dynamic method has low bias in MBF estimates (0 to [Formula: see text]) compared to linearly interpreted static assessment (0.45 to [Formula: see text]), making it more suitable for quantitative estimation. At matched radiation dose levels, receiver operating characteristic analysis demonstrated that the static method, with its high bias but generally lower variance, had superior performance ([Formula: see text]) in stratifying patients, especially for larger patients and lower contrast doses [area under the curve [Formula: see text] to 96 versus 0.86]. We also demonstrate that static assessment with a correctly tuned exponential relationship between the apparent CT number and MBF has superior quantification performance to static assessment with a linear relationship and to dynamic assessment. However, tuning the exponential relationship to the patient and scan characteristics will likely prove challenging. This study demonstrates that the selection and optimization of static or dynamic acquisition modes should depend on the specific clinical task.

  5. Ultrarapid quantitation of maize proteins by perfusion and monolithic reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Rodríguez-Nogales, J M; del Alamo, M; García, M C; Cifuentes, A; Marina, M L

    2009-04-22

    The main objective of this study was to develop a new methodology alternative to the classical Kjeldahl analysis for determining maize proteins in maize products and seeds. For that purpose, two different chromatographic methodologies using perfusion and monolithic stationary phases, both enabling rapid separations of maize proteins, were investigated. Due to the difficulty to find suitable standards for this type of analysis, three different maize products were initially tested as proteins standards: zein F4000, corn gluten meal, and maize flour. Different figures of merit (i.e., linearity, correlation coefficient, precision, limits of detection and quantitation), as well as the presence of matrix inferences, were investigated. The results obtained for the different chromatographic stationary phases and protein standards were compared in order to select the most suitable analytical conditions. Despite both perfusion and monolithic methodologies resulting, in general, as appropriate for the quantitation of maize proteins, the highest reduction of analysis time and lowest detection and determination limits provided by perfusion methodology enabled to select this one as the method of choice for the quantitation of maize proteins. Regarding the different protein standards studied in this work, in general the best results were obtained using the zein standard. Compared to Kjeldahl methodology, perfusion chromatography yields total protein contents in shorter analysis time while enabling the separation of the different kinds of proteins. Due to the high diversity and complexity of industrial maize products, the proposed chromatographic method could be a very useful tool for their routine analysis.

  6. Organ perfusion during voluntary pulmonary hyperinflation; a magnetic resonance imaging study

    DEFF Research Database (Denmark)

    Kristensen, Kasper Kyhl; Drvis, Ivan; Barak, Otto

    2016-01-01

    . Myocardial, pulmonary, skeletal muscle, kidney, and liver perfusion were evaluated by magnetic resonance imaging in 10 elite breath-hold divers at rest and during moderate GPI. Cardiac chamber volumes, stroke volume, and thus CO were determined from cardiac short-axis cine images. Organ volumes were assessed...

  7. Non-invasive imaging in detecting myocardial viability: Myocardial function versus perfusion

    Directory of Open Access Journals (Sweden)

    Iqbal A. Elfigih

    2014-12-01

    Full Text Available Coronary artery disease (CAD is the most prevalent and single most common cause of morbidity and mortality [1] with the resulting left ventricular (LV dysfunction an important complication. The distinction between viable and non-viable myocardium in patients with LV dysfunction is a clinically important issue among possible candidates for myocardial revascularization. Several available non-invasive techniques are used to detect and assess ischemia and myocardial viability. These techniques include echocardiography, radionuclide images, cardiac magnetic resonance imaging and recently myocardial computed tomography perfusion imaging. This review aims to distinguish between the available non-invasive imaging techniques in detecting signs of functional and perfusion viability and identify those which have the most clinical relevance in detecting myocardial viability in patients with CAD and chronic ischemic LV dysfunction. The most current available studies showed that both myocardial perfusion and function based on non-invasive imaging have high sensitivity with however wide range of specificity for detecting myocardial viability. Both perfusion and function imaging modalities provide complementary information about myocardial viability and no optimum single imaging technique exists that can provide very accurate diagnostic and prognostic viability assessment. The weight of the body of evidence suggested that non-invasive imaging can help in guiding therapeutic decision making in patients with LV dysfunction.

  8. Validation of near-infrared laser speckle imaging for assessing microvascular (re)perfusion

    NARCIS (Netherlands)

    R. Bezemer; E. Klijn; M. Khalilzada; A. Lima; M. Heger; J. van Bommel; C. Ince

    2010-01-01

    The present study was conducted to compare laser speckle imaging (LSI) with sidestream dark field (SDF) imaging (i.e. capillary microscopy) so as to validate the use of LSI for assessing microvascular (re)perfusion. For this purpose, LSI and SDF measurements were performed on the human nail fold dur

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

    Directory of Open Access Journals (Sweden)

    Ferreira Pedro F

    2012-06-01

    Full Text Available Abstract Background First-pass myocardial perfusion is often imaged with a tailored hybrid centric interleaved echo-planar-imaging sequence, providing rapid image acquisition with good contrast enhancement. The centric interleaved phase-encode order minimises the effective time-of-echo but it is sensitive to frequency-offsets. This short article aims to show possible artefacts that might originate with this sequence, in the context of first-pass perfusion imaging, when frequency-offsets are present. Non-uniform magnitude modulation effects were also analysed. Methods Numerical and phantom simulations were used to illustrate the effects of frequency-offsets and non-uniform magnitude modulation with this sequence in a typical perfusion protocol. In vivo data was post-processed to analyse the h-EPI’s sensitivity to the frequency-offsets. Results The centric phase-order was shown to be highly sensitive to frequency-offsets due to its symmetrical phase slope. Resulting artefacts include blurring, and splitting of the image into two identical copies along the phase-encode direction. It was also shown that frequency-offsets can introduce signal loss and ghosting of the right ventricle signal into the myocardium. The in vivo results were confirmed by numerical and phantom simulations. Magnitude modulation effects were found to be small. Conclusions Imaging first-pass myocardial perfusion with an hybrid centric echo-planar-imaging sequence can be corrupted with ghosting and splitting of the image due to frequency-offsets.

  10. 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.

  11. Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients

    Energy Technology Data Exchange (ETDEWEB)

    Le Faivre, Julien; Khung, Suonita; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Duhamel, Alain [University of Lille, Department of Biostatistics, Lille (France); Lamblin, Nicolas [University of Lille, Department of Cardiology, Cardiology Hospital, Lille (France)

    2016-11-15

    To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Saeid Mahmoudian

    2012-01-01

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

  13. Relative indexes of cutaneous blood perfusion measured by real-time laser Doppler imaging (LDI) in healthy volunteers.

    Science.gov (United States)

    Seyed Jafari, S Morteza; Schawkat, Megir; Van De Ville, Dimitri; Shafighi, Maziar

    2014-07-01

    We used real-time LDI to study regional variations in microcirculatory perfusion in healthy candidates to establish a new methodology for global perfusion body mapping that is based on intra-individual perfusion index ratios. Our study included 74 (37 female) healthy volunteers aged between 22 and 30 years (mean 24.49). Imaging was performed using a recent microcirculation-imaging camera (EasyLDI) for different body regions of each volunteer. The perfusion values were reported in Arbitrary Perfusion Units (APU). The relative perfusion indexes for each candidate's body region were then obtained by normalization with the perfusion value of the forehead. Basic parameters such as weight, height, and blood pressure were also measured and analyzed. The highest mean perfusion value was reported in the forehead area (259.21APU). Mean perfusion in the measured parts of the body correlated positively with mean forehead value, while there was no significant correlation between forehead blood perfusion values and room temperature, BMI, systolic blood pressure and diastolic blood pressure (p=0.420, 0.623, 0.488, 0.099, respectively). Analysis of the data showed that perfusion indexes were not significantly different between male and female volunteers except for the ventral upper arm area (p=.001). LDI is a non-invasive, fast technique that opens several avenues for clinical applications. The mean perfusion indexes are useful in clinical practice for monitoring patients before and after surgical interventions. Perfusion values can be predicted for different body parts for patients only by taking the forehead perfusion value and using the perfusion index ratios to obtain expected normative perfusion values. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. 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...

  15. Detecting physiological systems with laser speckle perfusion imaging of the renal cortex.

    Science.gov (United States)

    Scully, Christopher G; Mitrou, Nicholas; Braam, Branko; Cupples, William A; Chon, Ki H

    2013-06-01

    Laser speckle perfusion imaging (LSPI) has become an increasingly popular technique for monitoring vascular perfusion over a tissue surface. However, few studies have utilized the full range of spatial and temporal information generated by LSPI to monitor spatial properties of physiologically relevant dynamics. In this study, we extend the use of LSPI to analyze renal perfusion dynamics over a spatial surface of ~5 × 7 mm of renal cortex. We identify frequencies related to five physiological systems that induce temporal changes in renal vascular perfusion (cardiac flow pulse, respiratory-induced oscillations, baroreflex components, the myogenic response, and tubuloglomerular feedback) across the imaged surface and compare the results with those obtained from renal blood flow measurements. We find that dynamics supplied from global sources (cardiac, respiration, and baroreflex) present with the same frequency at all locations across the imaged surface, but the local renal autoregulation dynamics can be heterogeneous in their distribution across the surface. Moreover, transfer function analysis with forced blood pressure as the input yields the same information with laser speckle imaging or renal blood flow as the output during control, intrarenal infusion of N(ω)-nitro-L-arginine methyl ester to enhance renal autoregulation, and intrarenal infusion of the rho-kinase inhibitor Y-27632 to inhibit vasomotion. We conclude that LSPI measurements can be used to analyze local as well as global renal perfusion dynamics and to study the properties of physiological systems across the renal cortex.

  16. Comparison of heterogeneity quantification algorithms for brain SPECT perfusion images

    OpenAIRE

    Modzelewski, Romain; Janvresse, Elise; De La Rue, Thierry; Vera, Pierre

    2012-01-01

    Background Several algorithms from the literature were compared with the original random walk (RW) algorithm for brain perfusion heterogeneity quantification purposes. Algorithms are compared on a set of 210 brain single photon emission computed tomography (SPECT) simulations and 40 patient exams. Methods Five algorithms were tested on numerical phantoms. The numerical anthropomorphic Zubal head phantom was used to generate 42 (6 × 7) different brain SPECT simulations. Seven diffuse cortical ...

  17. CT imaging of myocardial perfusion and viability. Beyond structure and function

    Energy Technology Data Exchange (ETDEWEB)

    Schoepf, U. Joseph [Medical University of South Carolina, Charleston, SC (United States). Dept. of Radiology and Radiological Sciences; Bamberg, Fabian [Muenchen Univ. (Germany); Bastarrika, Gorka [Sunnybrook Health Sciences Centre, Toronto, ON (Canada). Cardiothoracic Imaging Division; Ruzsics, Balazs [Royal Liverpool and Broadgreen Univ., Liverpool (United Kingdom). Dept. of Cardiology; Vliegenthart, Rozemarijn (ed.) [University Medical Center Groningen (Netherlands). Center for Medical Imaging

    2014-06-01

    First publication to be devoted to the subject. Reviews an advanced, promising application in healthcare. Spans multiple medical disciplines. The rapid evolution in cardiac computed tomography during the past decade has improved spatial and temporal resolution to the extent that cardiac CT is now an accepted alternative for the non-invasive interrogation of the heart. Beyond the assessment of cardiac structure and ventricular function, recent research has identified yet another promising CT application for the comprehensive diagnosis of coronary heart disease, namely the assessment of myocardial perfusion and viability. In this book, the first to be devoted to this novel application of CT, leading experts from across the world present up-to-date information and consider future directions. After short sections outlining the state of the art in the traditional applications of CT to image structure and function, the full range of CT techniques that may be employed to evaluate the myocardial blood supply are discussed in detail. Similarly, diverse CT approaches for the assessment of myocardial viability are described, with careful consideration of the available experimental and clinical evidence and the role of quantitative imaging.

  18. Quantitative hepatic CT perfusion measurement: Comparison of Couinaud's hepatic segments with dual-source 128-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuan [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Xue, Hua-dan, E-mail: bjdanna95@hotmail.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Jin, Zheng-yu, E-mail: jin_zhengyu@163.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Su, Bai-yan; Li, Zhuo; Sun, Hao; Chen, Yu; Liu, Wei [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China)

    2013-02-15

    Purpose: To compare the quantitative liver computed tomography perfusion (CTP) differences among eight hepatic segments. Materials and methods: This retrospective study was based on 72 acquired upper abdomen CTP scans for detecting suspected pancreas tumor. Patients with primary or metastatic liver tumor, any focal liver lesions except simple cyst (<3 cm in diameter), history of liver operation or splenectomy, evidence of liver cirrhosis or invasion of portal vein were excluded. The final analysis included 50 patients (M:F = 21:29, mean age = 43.2 years, 15–76 years). Arterial liver perfusion (ALP), portal-venous perfusion (PVP), total hepatic perfusion (THP = ALP + PVP), and hepatic perfusion index (HPI) of each hepatic segment were calculated and compared by means of one-way analysis of variance (ANOVA) and the Bonferonni correction method. Results: Compared to hepatic segments 5, 6, 7 and 8, segments 2 and 3 showed a tendency of higher ALPs, lower PVPs, and higher HPIs, most of which were statistically significant (p < 0.05). Hepatic segments 1 and 4 had higher mean values of ALP and HPI and lower mean values of PVP than segments 5, 6, 7 and 8 as well, although no significant differences were detected except for ALP and HPI for liver segments 1 and 7 (p = 0.001 and 0.035 respectively), and ALP for liver segments 1 and 5 (p = 0.039). Higher ALP and HPI were showed in hepatic segment 3 compared to segment 4 (p = 0.000 and 0.000 respectively). No significant differences were found for THP among eight segments. Conclusions: Intra-hepatic perfusion differences exist in normal hepatic parenchyma especially between lateral sector (segments 2 and 3) and right lobe (segments 5, 6, 7 and 8). This might have potential clinical significance in liver-perfusion-related protocol design and result analysis.

  19. Adding attenuation corrected images in myocardial perfusion imaging reduces the need for a rest study.

    Science.gov (United States)

    Trägårdh, Elin; Valind, Sven; Edenbrandt, Lars

    2013-04-01

    The American Society of Nuclear Cardiology and the Society of Nuclear Medicine conclude that incorporation of attenuation corrected (AC) images in myocardial perfusion scintigraphy (MPS) will improve diagnostic accuracy. The aim was to investigate the value of adding AC stress-only images for the decision whether a rest study is necessary or not. 1,261 patients admitted to (99m)Tc MPS were studied. The stress studies were interpreted by two physicians who judged each study as "no rest study necessary" or "rest study necessary", by evaluating NC stress-only and NC + AC stress-only images. When there was disagreement between the two physicians, a third physician evaluated the studies. Thus, agreement between 2 out of 3 physicians was evaluated. The physicians assessed 214 more NC + AC images than NC images as "no rest study necessary" (17% of the study population). The number of no-rest-study-required was significantly higher for NC + AC studies compared to NC studies (859 vs 645 cases (p rest study necessary" (22 NC + AC cases; 8 NC cases), (no statistically significant difference). In 11 of these, the final report stated "suspected/possible ischemia or infarction in a small area". Adding AC stress-only images to NC stress-only images reduce the number of unnecessary rest studies substantially.

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

    Science.gov (United States)

    Zhou, Quan; Dong, Yang; Chen, WenLi; Lin, Xueying; Xing, Da; Huang, Li

    2007-05-01

    Cerebrovascular disease is one of the leading causes of death, and approximately 50% of survivors have a residual neurologic deficit and greater than 25% require chronic care. Cerebrovascular reserve capacity (CVRC) describes how far cerebral perfusion can increase from a baseline value after stimulation. High blood pressure is the most important independent risk factor for stroke and other vascular diseases. The incidence of stroke in the hypertensive is six times higher than in the patient with normal blood pressure. CVRC in the hypertensive was even lower than in control patients. MR perfusion weighted imaging (MR PWI) with the well-established acetazolamide (ACZ) stimulation test has been used for assessing brain function. The aim of this work is to assess the cerebrovascular reserve capacity by MR PWI with "ACZ" tolerance test in spontaneous hypertensive rat (SHR) and to identify its value in evaluating the CVRC. Experimental animal including 3 groups: Wistar-Kyoto rats (WKY) (12-week-old) as control group, SHR (12-week-old and 20-week-old) as experimental group. MR PWI was performed respectively before and after acetazolamide administrated orally in 3 groups on a clinical 1.5 Tesla GE Signa MR fx/i whole-body MR system. The ROI was chosen in the bilateral frontal lobe to measure the value of rCBV, rCBF and MTT. The results showed that before ACZ-test, there was statistic differences between the WKY and SHR(12-week-old), and between SHR(12-week-old) and SHR(20-week-old) in the values of rCBV and rCBF (P>0.05), and after ACZ-test, there were statistic differences between WKY and SHR (20-week-old), and between SHR(12-week-old) and SHR(20-week-old) in the rCBV value (P<0.05). It is concluded that the method of MRI PWI combined with the "ACZ stress test" can provide more qualitative and half-quantitative information on the cerebral perfusion to evaluate the CVRC in SHR.

  1. White-light Quantitative Phase Imaging Unit

    CERN Document Server

    Baek, YoonSeok; Yoon, Jonghee; Kim, Kyoohyun; Park, YongKeun

    2016-01-01

    We introduce the white light quantitative phase imaging unit (WQPIU) as a practical realization of quantitative phase imaging (QPI) on standard microscope platforms. The WQPIU is a compact stand-alone unit which measures sample induced phase delay under white-light illumination. It does not require any modification of the microscope or additional accessories for its use. The principle of the WQPIU based on lateral shearing interferometry and phase shifting interferometry provides a cost-effective and user-friendly use of QPI. The validity and capacity of the presented method are demonstrated by measuring quantitative phase images of polystyrene beads, human red blood cells, HeLa cells and mouse white blood cells. With speckle-free imaging capability due to the use of white-light illumination, the WQPIU is expected to expand the scope of QPI in biological sciences as a powerful but simple imaging tool.

  2. Application of time sampling in brain CT perfusion imaging for dose reduction

    Science.gov (United States)

    Lee, S. H.; Kim, J. H.; Kim, K. G.; Park, S. J.; Im, Jung Gi

    2007-03-01

    The purpose of this study is to determine a stable sampling rate not to be affected by sampling shift for reducing radiation exposure with time sampling and interpolation in cerebral perfusion CT examination. Original images were obtained every 1 second for 40 time series from 3 patients, respectively. Time sampling was performed with sampling intervals (SI) from 2 to 10 seconds. Sampling shift was applied from +1 to SI-1 for each sampling rate. For each patient, 30 tissue concentration time-course data were collected, and arterial input curves were fitted by gamma-variate function. The sinc function was introduced for interpolation. Deconvolution analysis based on SVD was performed for quantifying perfusion parameters. The perfusion values through time-varying sampling and interpolation were statistically compared with the original perfusion values. The mean CBF values with increase of sampling interval and shift magnitude from the collected data had a wider fluctuation pattern centering around the original mean CBF. The mean CBV values had a similar tendency to the mean CBF values, but a relatively narrower deviation. The mean MTT values were fluctuated reversely to the trend of the mean CBF values. The stable sampling interval for quantifying perfusion parameters with lower radiation exposure was statistically acceptable up to 4 seconds. These results indicate that sampling shift limits sampling rate for acquiring acceptable perfusion values. This study will help in selecting more reasonable sampling rate for low-radiation-dose CT examination.

  3. Quantiifcation of angiogenesis by CT perfusion imaging in liver tumor of rabbit

    Institute of Scientific and Technical Information of China (English)

    Hui-Jie Jiang; Zai-Ren Zhang; Bao-Zhong Shen; Yong Wan; Hong Guo; Jin-Ping Li

    2009-01-01

    BACKGROUND: Tumor angiogenesis is essential for primary and metastatic tumor growth. Computed tomography perfusion (CTP) is a new imaging method, made possible by the recent development of fast CT scanners and improved data analysis techniques, which allows measurement of the physiologic and hemodynamic properties of tissue vasculature. This study aimed to evaluate CTP in the quantiifcation of angiogenesis and to assess the relationship between tissue perfusion parameters and microvascular density (MVD) and vascular endothelial growth factor (VEGF), attempting to detect the physiologic properties of angiogenesis. METHODS: Sixteen rabbits with VX2 liver tumors underwent multi-slice CT perfusion (MSCTP) on day 14 after tumor inoculation. CTP parameters included hepatic blood lfow (HBF), hepatic blood volume (HBV), mean transit time (MTT), permeability of capillary vessel surface (PS), hepatic artery index (HAI), hepatic artery perfusion (HAP), and hepatic portal perfusion (HPP). The border of the tumor was stained with CD34 and VEGF immunohistochemical stains, and MVD was measured by anti-CD34. Then, CTP parameters were determined whether they were correlated with MVD and VEGF using Pearson’s correlation coefifcient. RESULTS: The positive expression of MVD was different in the center and border of the tumor (P0.05). CONCLUSIONS: Signiifcant correlations were found between perfusion parameters and MVD and VEGF. Therefore, MSCTP can be used to evaluate tumor angiogenesisin vivo.

  4. Perfusion information extracted from resting state functional magnetic resonance imaging.

    Science.gov (United States)

    Tong, Yunjie; Lindsey, Kimberly P; Hocke, Lia M; Vitaliano, Gordana; Mintzopoulos, Dionyssios; Frederick, Blaise deB

    2017-02-01

    It is widely known that blood oxygenation level dependent (BOLD) contrast in functional magnetic resonance imaging (fMRI) is an indirect measure for neuronal activations through neurovascular coupling. The BOLD signal is also influenced by many non-neuronal physiological fluctuations. In previous resting state (RS) fMRI studies, we have identified a moving systemic low frequency oscillation (sLFO) in BOLD signal and were able to track its passage through the brain. We hypothesized that this seemingly intrinsic signal moves with the blood, and therefore, its dynamic patterns represent cerebral blood flow. In this study, we tested this hypothesis by performing Dynamic Susceptibility Contrast (DSC) MRI scans (i.e. bolus tracking) following the RS scans on eight healthy subjects. The dynamic patterns of sLFO derived from RS data were compared with the bolus flow visually and quantitatively. We found that the flow of sLFO derived from RS fMRI does to a large extent represent the blood flow measured with DSC. The small differences, we hypothesize, are largely due to the difference between the methods in their sensitivity to different vessel types. We conclude that the flow of sLFO in RS visualized by our time delay method represents the blood flow in the capillaries and veins in the brain.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-15

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

  8. Perfusion imaging of brain gliomas using arterial spin labeling: correlation with histopathological vascular density in MRI-guided biopsies

    Energy Technology Data Exchange (ETDEWEB)

    Di, Ningning; Pang, Haopeng; Ren, Yan; Yao, Zhenwei; Feng, Xiaoyuan [Huashan Hospital Fudan University, Department of Radiology, Shanghai (China); Dang, Xuefei [Shang Hai Gamma Knife Hospital, Shanghai (China); Cheng, Wenna [Binzhou Medical University Affiliated Hospital, Department of Pharmacy, Binzhou (China); Wu, Jingsong; Yao, Chengjun [Huashan Hospital Fudan University, Department of Neurosurgery, Shanghai (China)

    2017-01-15

    This study was designed to determine if cerebral blood flow (CBF) derived from arterial spin labeling (ASL) perfusion imaging could be used to quantitatively evaluate the microvascular density (MVD) of brain gliomas on a ''point-to-point'' basis by matching CBF areas and surgical biopsy sites as accurate as possible. The study enrolled 47 patients with treatment-naive brain gliomas who underwent preoperative ASL, 3D T1-weighted imaging with gadolinium contrast enhancement (3D T1C+), and T2 fluid acquisition of inversion recovery (T2FLAIR) sequences before stereotactic surgery. We histologically quantified MVD from CD34-stained sections of stereotactic biopsies and co-registered biopsy locations with localized CBF measurements. The correlation between CBF and MVD was determined using Spearman's correlation coefficient. P ≤.05 was considered statistically significant. Of the 47 patients enrolled in the study, 6 were excluded from the analysis because of brain shift or poor co-registration and localization of the biopsy site during surgery. Finally, 84 biopsies from 41 subjects were included in the analysis. CBF showed a statistically significant positive correlation with MVD (ρ = 0.567; P =.029). ASL can be a useful noninvasive perfusion MR method for quantitative evaluation of the MVD of brain gliomas. (orig.)

  9. Quantitative histogram analysis of images

    Science.gov (United States)

    Holub, Oliver; Ferreira, Sérgio T.

    2006-11-01

    A routine for histogram analysis of images has been written in the object-oriented, graphical development environment LabVIEW. The program converts an RGB bitmap image into an intensity-linear greyscale image according to selectable conversion coefficients. This greyscale image is subsequently analysed by plots of the intensity histogram and probability distribution of brightness, and by calculation of various parameters, including average brightness, standard deviation, variance, minimal and maximal brightness, mode, skewness and kurtosis of the histogram and the median of the probability distribution. The program allows interactive selection of specific regions of interest (ROI) in the image and definition of lower and upper threshold levels (e.g., to permit the removal of a constant background signal). The results of the analysis of multiple images can be conveniently saved and exported for plotting in other programs, which allows fast analysis of relatively large sets of image data. The program file accompanies this manuscript together with a detailed description of two application examples: The analysis of fluorescence microscopy images, specifically of tau-immunofluorescence in primary cultures of rat cortical and hippocampal neurons, and the quantification of protein bands by Western-blot. The possibilities and limitations of this kind of analysis are discussed. Program summaryTitle of program: HAWGC Catalogue identifier: ADXG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXG_v1_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computers: Mobile Intel Pentium III, AMD Duron Installations: No installation necessary—Executable file together with necessary files for LabVIEW Run-time engine Operating systems or monitors under which the program has been tested: WindowsME/2000/XP Programming language used: LabVIEW 7.0 Memory required to execute with typical data:˜16MB for starting and ˜160MB used for

  10. Stress Myocardial Perfusion Imaging in the Emergency Department - New Techniques for Speed and Diagnostic Accuracy

    OpenAIRE

    Harrison, Sheri D; Harrison, Mark A; Duvall, W. Lane

    2012-01-01

    Emergency room evaluations of patients presenting with chest pain continue to rise, and these evaluations which often include cardiac imaging, are an increasing area of resource utilization in the current health system. Myocardial perfusion imaging from the emergency department remains a vital component of the diagnosis or exclusion of coronary artery disease as the etiology of chest pain. Recent advances in camera technology, and changes to the imaging protocols have allowed MPI to become a ...

  11. Performance evaluation of a pinhole SPECT system for myocardial perfusion imaging of mice.

    Science.gov (United States)

    Wu, Max C; Hasegawa, Bruce H; Dae, Michael W

    2002-12-01

    The increasing use of transgenic mice as models of human physiology and disease has motivated the development of dedicated in vivo imaging systems for anatomic and functional characterization of mice as an adjunct to or a replacement for established ex vivo techniques. We have developed a pinhole single photon emission computed tomography (SPECT) system for high resolution imaging of mice with cardiovascular imaging as the primary application. In this work, we characterize the system performance through phantom studies. The spatial resolution and sensitivity were measured from images of a line source and point source, respectively, and were reported for a range of object-to-pinhole distances and pinhole diameters. Tomographic images of a uniform cylindrical phantom, Defrise phantom, and grid phantom were used to characterize the image uniformity and spatial linearity. The uniform phantom image did not contain any ring or reconstruction artifacts, but blurring in the axial direction was evident in the Defrise phantom images. The grid phantom images demonstrated excellent spatial linearity. A novel phantom modeling perfusion of the left ventricle of a mouse was designed and built with perfusion defects of varying sizes to evaluate the system performance for myocardial perfusion imaging of mice. The defect volumes were measured from the pinhole SPECT images and correlated to the actual defect volumes calculated according to geometric formulas. Linear regression analysis produced a correlation coefficient of r = 0.995 (p defect size in mice using pinhole SPECT. We have performed phantom studies to characterize the spatial resolution, sensitivity, image uniformity, and spatial linearity of the pinhole SPECT system. Measurement of the perfusion defect size is a valuable phenotypic assessment and will be useful for hypothesis testing in murine models of cardiovascular disease.

  12. Image analysis of intracranial high perfusion lesion by whole brain one-stop imaging technique with 320 detector rows CT

    Directory of Open Access Journals (Sweden)

    Fei-zhou DU

    2014-03-01

    Full Text Available Objective  The perfusion and vascular architecture features were investigated and evaluated by use of one-stop imaging technique with 320 rows CT for exploring the clinical value of one-stop imaging technique in the diagnosis of intracranial lesions. Methods  The perfusion parameters and vascular architecture of intracranial high perfusion lesions of 52 patients were collected in General Hospital of Chengdu Command from Oct. 2010 to Apr. 2013, who were examined by one-stop imaging technique with 320 rows CT, were retrospectively analyzed. The perfusion values of normal contralateral cerebral tissue were used as control to analyze the perfusion and vascular architecture features of injured parts. Results  Of the 52 patients, there were 16 cases of subacute cerebral infarction, 9 cases of arteriovenous malformation, 7 cases of hemangioma, 12 cases of meningioma, and 8 cases of glioma. All the patients showed elevated CBV and/or CBF and different changes in mean transit time (MTT, time to peak (TTP and delay time (Delay. In the cases of subacute cerebral infarction, the parameters of MTT, TTP and Delay increased. In the cases of arteriovenous malformation, all the parameters decreased. In the cases of hemangioma, the MTT decreased, while TTP and Delay increased. In the cases of glioma, the TTP and Delay increased, while the change of MTT varied. Meanwhile, abnormality of vascular structures was found in all the cases by CT angiography. Conclusion  With whole brain perfusion and one-stop vascular imaging with 320 rows CT, the perfusion characteristics of intracranial lesions can be revealed completely, including blood supply and microcirculation changes in the lesions, and it may be of benefit in guiding the clinical diagnosis and treatment. DOI: 10.11855/j.issn.0577-7402.2014.03.10

  13. Evaluation of angiogenesis in colorectal carcinoma with multidetector-row CT multislice perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Feng Shiting, E-mail: fst1977@163.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Sun Canhui, E-mail: canhuisun@sina.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Li Ziping, E-mail: liziping163@tom.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Mak, Henry Ka-Fung, E-mail: makkf@hkucc.hku.h [Department of Diagnostic Radiology, University of Hong Kong, Hong Kong (China); Peng Zhenpeng, E-mail: ppzhen@21cn.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Guo Huanyi, E-mail: guohuanyi@163.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China); Meng Quanfei, E-mail: mzycoco@gmail.co [Department of Radiology, First Affiliated Hospital of SunYat-sen University, Guangzhou 510080 (China)

    2010-08-15

    To evaluate the correlation between 64 multidetector-row CT (64MDCT) perfusion imaging in colorectal carcinoma and microvessel density (MVD) and vascular endothelial growth factor (VEGF), 64MDCT perfusion imaging was performed in 33 patients with pathologically verified colorectal carcinoma. These images were analyzed with perfusion functional software, and time-density curves (TDC) were created for the region of interest (ROI) encompassing the tumor, the target artery and vein. The individual perfusion maps generated indicated blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS). MVD and VEGF were evaluated by immunohistochemical staining with anti-CD34 and anti-VEGF, respectively. Correlations between MVD or VEGF with CT perfusion parameters and clinicopathological factors (Dukes' stages, invasion depth, and lymph node and liver metastasis) were also investigated. MVD in the colorectal carcinoma was 22.61 {+-} 9.01 per x200 field. The scores obtained for VEGF expression were 4.15 {+-} 1.09. VEGF staining was positive in 25 of 29 tumors (86.2%). There was no significant correlation between the presence of MVD, VEGF expression and clinicopathological factors (P > 0.05). There was also no correlation between MVD, VEGF expression, and any dynamic CT parameters (P > 0.05). The BV and MTT were significantly higher in tumors demonstrating serous coat invasion than in those without it (t = -2.63, -2.24, P = 0.0137, 0.0331, respectively). BV was also significantly correlated with tumor size (r = 0.41, P = 0.02). Neither BF nor PS was correlated with clinicopathological factors. In conclusion, 64MDCT perfusion imaging, MVD, and VEGF may reflect angiogenic activity, but no significant correlation among these factors.

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

    Science.gov (United States)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2006-01-21

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

  16. Cancer detection by quantitative fluorescence image analysis.

    Science.gov (United States)

    Parry, W L; Hemstreet, G P

    1988-02-01

    Quantitative fluorescence image analysis is a rapidly evolving biophysical cytochemical technology with the potential for multiple clinical and basic research applications. We report the application of this technique for bladder cancer detection and discuss its potential usefulness as an adjunct to methods used currently by urologists for the diagnosis and management of bladder cancer. Quantitative fluorescence image analysis is a cytological method that incorporates 2 diagnostic techniques, quantitation of nuclear deoxyribonucleic acid and morphometric analysis, in a single semiautomated system to facilitate the identification of rare events, that is individual cancer cells. When compared to routine cytopathology for detection of bladder cancer in symptomatic patients, quantitative fluorescence image analysis demonstrated greater sensitivity (76 versus 33 per cent) for the detection of low grade transitional cell carcinoma. The specificity of quantitative fluorescence image analysis in a small control group was 94 per cent and with the manual method for quantitation of absolute nuclear fluorescence intensity in the screening of high risk asymptomatic subjects the specificity was 96.7 per cent. The more familiar flow cytometry is another fluorescence technique for measurement of nuclear deoxyribonucleic acid. However, rather than identifying individual cancer cells, flow cytometry identifies cellular pattern distributions, that is the ratio of normal to abnormal cells. Numerous studies by others have shown that flow cytometry is a sensitive method to monitor patients with diagnosed urological disease. Based upon results in separate quantitative fluorescence image analysis and flow cytometry studies, it appears that these 2 fluorescence techniques may be complementary tools for urological screening, diagnosis and management, and that they also may be useful separately or in combination to elucidate the oncogenic process, determine the biological potential of tumors

  17. Use of diffusion and perfusion magnetic resonance imaging as a tool in acute stroke clinical trials

    Directory of Open Access Journals (Sweden)

    Warach Steven

    2001-01-01

    Full Text Available Abstract In light of the slow progress in developing effective therapies for ischemic stroke, magnetic resonance imaging techniques have emerged as new tools in stroke clinical trials. Rapid imaging with magnetic resonance imaging, diffusion weighted imaging, perfusion imaging and angiography are being incorporated into phase II and phase III stroke trials to optimize patient selection based on positive imaging diagnosis of the ischemic pathophysiology specifically related to a drug's mechanism of action and as a direct biomarker of the effect of a treatment's effect on the brain.

  18. Noninvasive metabolic imaging of engineered 3D human adipose tissue in a perfusion bioreactor.

    Directory of Open Access Journals (Sweden)

    Andrew Ward

    Full Text Available The efficacy and economy of most in vitro human models used in research is limited by the lack of a physiologically-relevant three-dimensional perfused environment and the inability to noninvasively quantify the structural and biochemical characteristics of the tissue. The goal of this project was to develop a perfusion bioreactor system compatible with two-photon imaging to noninvasively assess tissue engineered human adipose tissue structure and function in vitro. Three-dimensional (3D vascularized human adipose tissues were engineered in vitro, before being introduced to a perfusion environment and tracked over time by automated quantification of endogenous markers of metabolism using two-photon excited fluorescence (TPEF. Depth-resolved image stacks were analyzed for redox ratio metabolic profiling and compared to prior analyses performed on 3D engineered adipose tissue in static culture. Traditional assessments with H&E staining were used to qualitatively measure extracellular matrix generation and cell density with respect to location within the tissue. The distribution of cells within the tissue and average cellular redox ratios were different between static and perfusion cultures, while the trends of decreased redox ratio and increased cellular proliferation with time in both static and perfusion cultures were similar. These results establish a basis for noninvasive optical tracking of tissue structure and function in vitro, which can be applied to future studies to assess tissue development or drug toxicity screening and disease progression.

  19. Noninvasive metabolic imaging of engineered 3D human adipose tissue in a perfusion bioreactor.

    Science.gov (United States)

    Ward, Andrew; Quinn, Kyle P; Bellas, Evangelia; Georgakoudi, Irene; Kaplan, David L

    2013-01-01

    The efficacy and economy of most in vitro human models used in research is limited by the lack of a physiologically-relevant three-dimensional perfused environment and the inability to noninvasively quantify the structural and biochemical characteristics of the tissue. The goal of this project was to develop a perfusion bioreactor system compatible with two-photon imaging to noninvasively assess tissue engineered human adipose tissue structure and function in vitro. Three-dimensional (3D) vascularized human adipose tissues were engineered in vitro, before being introduced to a perfusion environment and tracked over time by automated quantification of endogenous markers of metabolism using two-photon excited fluorescence (TPEF). Depth-resolved image stacks were analyzed for redox ratio metabolic profiling and compared to prior analyses performed on 3D engineered adipose tissue in static culture. Traditional assessments with H&E staining were used to qualitatively measure extracellular matrix generation and cell density with respect to location within the tissue. The distribution of cells within the tissue and average cellular redox ratios were different between static and perfusion cultures, while the trends of decreased redox ratio and increased cellular proliferation with time in both static and perfusion cultures were similar. These results establish a basis for noninvasive optical tracking of tissue structure and function in vitro, which can be applied to future studies to assess tissue development or drug toxicity screening and disease progression.

  20. First in vivo magnetic particle imaging of lung perfusion in rats

    Science.gov (United States)

    Zhou, Xinyi Y.; Jeffris, Kenneth E.; Yu, Elaine Y.; Zheng, Bo; Goodwill, Patrick W.; Nahid, Payam; Conolly, Steven M.

    2017-05-01

    Pulmonary embolism (PE), along with the closely related condition of deep vein thrombosis, affect an estimated 600 000 patients in the US per year. Untreated, PE carries a mortality rate of 30%. Because many patients experience mild or non-specific symptoms, imaging studies are necessary for definitive diagnosis of PE. Iodinated CT pulmonary angiography is recommended for most patients, while nuclear medicine-based ventilation/perfusion (V/Q) scans are reserved for patients in whom the use of iodine is contraindicated. Magnetic particle imaging (MPI) is an emerging tracer imaging modality with high image contrast (no tissue background signal) and sensitivity to superparamagnetic iron oxide (SPIO) tracer. Importantly, unlike CT or nuclear medicine, MPI uses no ionizing radiation. Further, MPI is not derived from magnetic resonance imaging (MRI); MPI directly images SPIO tracers via their strong electronic magnetization, enabling deep imaging of anatomy including within the lungs, which is very challenging with MRI. Here, the first high-contrast in vivo MPI lung perfusion images of rats are shown using a novel lung perfusion agent, MAA-SPIOs.

  1. Alternative technique using dual source CT imaging for assessment of myocardial perfusion

    Directory of Open Access Journals (Sweden)

    Amgad S. Abdel-Rahman

    2015-06-01

    Conclusion: We propose that comprehensive evaluation of coronary artery morphology and myocardial perfusion in patients with CAD could be achieved by single reproducible non-invasive contrast enhanced CT acquisition using DSCT scanners while operated in single energy mode with high sensitivity, specificity and diagnostic accuracy, it also has the potential to be the first, independent and stand out imaging choice in such field.

  2. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT : 2015 revision

    NARCIS (Netherlands)

    Verberne, Hein J.; Acampa, Wanda; Anagnostopoulos, Constantinos; Ballinger, Jim; Bengel, Frank; De Bondt, Pieter; Buechel, Ronny R.; Cuocolo, Alberto; van Eck-Smit, Berthe L. F.; Flotats, Albert; Hacker, Marcus; Hindorf, Cecilia; Kaufmann, Philip A.; Lindner, Oliver; Ljungberg, Michael; Lonsdale, Markus; Manrique, Alain; Minarik, David; Scholte, Arthur J. H. A.; Slart, Riemer H. J. A.; Tragardh, Elin; de Wit, Tim C.; Hesse, Birger

    2015-01-01

    Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated 201

  3. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT

    DEFF Research Database (Denmark)

    Verberne, Hein J; Acampa, Wanda; Anagnostopoulos, Constantinos;

    2015-01-01

    Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated ...

  4. Scatter and attenuation correction changes interpretation of gated myocardial perfusion imaging

    DEFF Research Database (Denmark)

    Johansen, Allan; Grupe, Peter; Veje, Annegrete

    2004-01-01

    Attenuation correction may improve the diagnostic accuracy of myocardial perfusion imaging (MPI). However, few studies have dealt with the clinical consequences for reporting. We compared routine reports based on scatter-corrected MPI (MPI-routine) with consensus readings of scatter-corrected (MP...

  5. Robust cranial cavity segmentation in CT and CT perfusion images of trauma and suspected stroke patients

    NARCIS (Netherlands)

    Patel, A; Ginneken, B. van; Meijer, F.J.A.; Dijk, E.J. van; Prokop, M.; Manniesing, R.

    2017-01-01

    A robust and accurate method is presented for the segmentation of the cranial cavity in computed tomography (CT) and CT perfusion (CTP) images. The method consists of multi-atlas registration with label fusion followed by a geodesic active contour levelset refinement of the segmentation.

  6. Quantitative Imaging in Cancer Clinical Trials.

    Science.gov (United States)

    Yankeelov, Thomas E; Mankoff, David A; Schwartz, Lawrence H; Lieberman, Frank S; Buatti, John M; Mountz, James M; Erickson, Bradley J; Fennessy, Fiona M M; Huang, Wei; Kalpathy-Cramer, Jayashree; Wahl, Richard L; Linden, Hannah M; Kinahan, Paul E; Zhao, Binsheng; Hylton, Nola M; Gillies, Robert J; Clarke, Laurence; Nordstrom, Robert; Rubin, Daniel L

    2016-01-15

    As anticancer therapies designed to target specific molecular pathways have been developed, it has become critical to develop methods to assess the response induced by such agents. Although traditional, anatomic CT, and MRI examinations are useful in many settings, increasing evidence suggests that these methods cannot answer the fundamental biologic and physiologic questions essential for assessment and, eventually, prediction of treatment response in the clinical trial setting, especially in the critical period soon after treatment is initiated. To optimally apply advances in quantitative imaging methods to trials of targeted cancer therapy, new infrastructure improvements are needed that incorporate these emerging techniques into the settings where they are most likely to have impact. In this review, we first elucidate the needs for therapeutic response assessment in the era of molecularly targeted therapy and describe how quantitative imaging can most effectively provide scientifically and clinically relevant data. We then describe the tools and methods required to apply quantitative imaging and provide concrete examples of work making these advances practically available for routine application in clinical trials. We conclude by proposing strategies to surmount barriers to wider incorporation of these quantitative imaging methods into clinical trials and, eventually, clinical practice. Our goal is to encourage and guide the oncology community to deploy standardized quantitative imaging techniques in clinical trials to further personalize care for cancer patients and to provide a more efficient path for the development of improved targeted therapies.

  7. Quantitative imaging of turbulent and reacting flows

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.H. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Quantitative digital imaging, using planar laser light scattering techniques is being developed for the analysis of turbulent and reacting flows. Quantitative image data, implying both a direct relation to flowfield variables as well as sufficient signal and spatial dynamic range, can be readily processed to yield two-dimensional distributions of flowfield scalars and in turn two-dimensional images of gradients and turbulence scales. Much of the development of imaging techniques to date has concentrated on understanding the requisite molecular spectroscopy and collision dynamics to be able to determine how flowfield variable information is encoded into the measured signal. From this standpoint the image is seen as a collection of single point measurements. The present effort aims at realizing necessary improvements in signal and spatial dynamic range, signal-to-noise ratio and spatial resolution in the imaging system as well as developing excitation/detection strategies which provide for a quantitative measure of particular flowfield scalars. The standard camera used for the study is an intensified CCD array operated in a conventional video format. The design of the system was based on detailed modeling of signal and image transfer properties of fast UV imaging lenses, image intensifiers and CCD detector arrays. While this system is suitable for direct scalar imaging, derived quantities (e.g. temperature or velocity images) require an exceptionally wide dynamic range imaging detector. To apply these diagnostics to reacting flows also requires a very fast shuttered camera. The authors have developed and successfully tested a new type of gated low-light level detector. This system relies on fast switching of proximity focused image-diode which is direct fiber-optic coupled to a cooled CCD array. Tests on this new detector show significant improvements in detection limit, dynamic range and spatial resolution as compared to microchannel plate intensified arrays.

  8. Feasibility of ASL spinal bone marrow perfusion imaging with optimized inversion time.

    Science.gov (United States)

    Xing, Dong; Zha, Yunfei; Yan, Liyong; Wang, Kejun; Gong, Wei; Lin, Hui

    2015-11-01

    To assess the correlation between flow-sensitive alternating inversion recovery (FAIR) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the measurement of spinal bone marrow (SBM) perfusion; in addition, to assess for an optimized inversion time (TI) as well as the reproducibility of SBM FAIR perfusion. The optimized TI of a FAIR SBM perfusion experiment was carried out on 14 volunteers; two adjacent vertebral bodies were selected from each volunteer to measure the change of signal intensity (ΔM) and the signal-to-noise ratio (SNR) of FAIR perfusion MRI with five different TIs. Then, reproducibility of FAIR data from 10 volunteers was assessed by the reposition SBM FAIR experiments. Finally, FAIR and DCE-MRI were performed on 27 subjects. The correlation between the blood flow on FAIR (BFASL ) and perfusion-related parameters on DCE-MRI was evaluated. The maximum value of ΔM and SNR were 36.39 ± 12.53 and 2.38 ± 0.97, respectively; both were obtained when TI was near 1200 msec. There were no significant difference between the two successive measurements of SBM BFASL perfusion (P = 0.879), and the within-subject coefficients of variation (wCV) of the measurements was 3.28%. The BFASL showed a close correlation with K(trans) (P FAIR perfusion scan protocol has good reproducibility, and as blood flow measurement on FAIR is reliable and closely related with the parameters on DCE-MRI, FAIR is feasible for measuring SBM blood flow. © 2015 Wiley Periodicals, Inc.

  9. Combined perfusion and doppler imaging using plane-wave nonlinear detection and microbubble contrast agents.

    Science.gov (United States)

    Tremblay-Darveau, Charles; Williams, Ross; Milot, Laurent; Bruce, Matthew; Burns, Peter N

    2014-12-01

    Plane-wave imaging offers image acquisition rates at the pulse repetition frequency, effectively increasing the imaging frame rates by up to two orders of magnitude over conventional line-by-line imaging. This form of acquisition can be used to achieve very long ensemble lengths in nonlinear modes such as pulse inversion Doppler, which enables new imaging trade-offs that were previously unattainable. We first demonstrate in this paper that the coherence of microbubble signals under repeated exposure to acoustic pulses of low mechanical index can be as high as 204 ± 5 pulses, which is long enough to allow an accurate power Doppler measurement. We then show that external factors, such as tissue acceleration, restrict the detection of perfusion at the capillary level with linear Doppler, even if long Doppler ensembles are considered. Hence, perfusion at the capillary level can only be detected with ultrasound through combined microbubbles and Doppler imaging. Finally, plane-wave contrast-enhanced power and color Doppler are performed on a rabbit kidney in vivo as a proof of principle. We establish that long pulse-inversion Doppler sequences and conventional wall-filters can create an image that simultaneously resolves both the vascular morphology of veins and arteries, and perfusion at the capillary level with frame rates above 100 Hz.

  10. Modeling laser speckle imaging of perfusion in the skin (Conference Presentation)

    Science.gov (United States)

    Regan, Caitlin; Hayakawa, Carole K.; Choi, Bernard

    2016-02-01

    Laser speckle imaging (LSI) enables visualization of relative blood flow and perfusion in the skin. It is frequently applied to monitor treatment of vascular malformations such as port wine stain birthmarks, and measure changes in perfusion due to peripheral vascular disease. We developed a computational Monte Carlo simulation of laser speckle contrast imaging to quantify how tissue optical properties, blood vessel depths and speeds, and tissue perfusion affect speckle contrast values originating from coherent excitation. The simulated tissue geometry consisted of multiple layers to simulate the skin, or incorporated an inclusion such as a vessel or tumor at different depths. Our simulation used a 30x30mm uniform flat light source to optically excite the region of interest in our sample to better mimic wide-field imaging. We used our model to simulate how dynamically scattered photons from a buried blood vessel affect speckle contrast at different lateral distances (0-1mm) away from the vessel, and how these speckle contrast changes vary with depth (0-1mm) and flow speed (0-10mm/s). We applied the model to simulate perfusion in the skin, and observed how different optical properties, such as epidermal melanin concentration (1%-50%) affected speckle contrast. We simulated perfusion during a systolic forearm occlusion and found that contrast decreased by 35% (exposure time = 10ms). Monte Carlo simulations of laser speckle contrast give us a tool to quantify what regions of the skin are probed with laser speckle imaging, and measure how the tissue optical properties and blood flow affect the resulting images.

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  12. Identifying the perfusion deficit in acute stroke with resting-state functional magnetic resonance imaging.

    Science.gov (United States)

    Lv, Yating; Margulies, Daniel S; Cameron Craddock, R; Long, Xiangyu; Winter, Benjamin; Gierhake, Daniel; Endres, Matthias; Villringer, Kersten; Fiebach, Jochen; Villringer, Arno

    2013-01-01

    Temporal delay in blood oxygenation level-dependent (BOLD) signals may be sensitive to perfusion deficits in acute stroke. Resting-state functional magnetic resonance imaging (rsfMRI) was added to a standard stroke MRI protocol. We calculated the time delay between the BOLD signal at each voxel and the whole-brain signal using time-lagged correlation and compared the results to mean transit time derived using bolus tracking. In all 11 patients, areas exhibiting significant delay in BOLD signal corresponded to areas of hypoperfusion identified by contrast-based perfusion MRI. Time delay analysis of rsfMRI provides information comparable to that of conventional perfusion MRI without the need for contrast agents. Copyright © 2012 American Neurological Association.

  13. Dual-energy lung perfusion computed tomography: a novel pulmonary functional imaging method.

    Science.gov (United States)

    Thieme, Sven F; Johnson, Thorsten R C; Reiser, Maximilian F; Nikolaou, Konstantin

    2010-08-01

    Dual-energy computed tomography (DECT) can be used for visualization of pulmonary microvascular contrast material distribution, representing regional perfusion. It is performed as DECT angiography and allows for the reconstruction of morphologic images as well as of "perfusion maps." The authors of previous studies have shown its potential to reliably depict perfusion defects, mainly in the context of pulmonary embolism. Also in the diagnostic work-up of other pulmonary diseases, there might be additional functional information provided by dual-energy acquisition techniques. This review focuses on the physical and technical background and the potential clinical value of pulmonary DECT. Technical improvements of a second-generation dual-source CT system are elucidated.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, Peter; Xyda, Argyro; Knauth, Michael [University of Goettingen, Medical Center, Department of Neuroradiology, Goettingen (Germany); Klotz, Ernst [Computed Tomography, SIEMENS Healthcare Sector, Forchheim (Germany); Tronnier, Volker [University Schleswig-Holstein, Department of Neurosurgery, Luebeck (Germany); Hartmann, Marius [University of Heidelberg, Medical Center, Division of Neuroradiology, Department of Neurology, Heidelberg (Germany)

    2010-10-15

    Perfusion computed tomography (PCT) allows to quantitatively assess haemodynamic characteristics of brain tissue. We investigated if different brain tumor types can be distinguished from each other using Patlak analysis of PCT data. PCT data from 43 patients with brain tumours were analysed with a commercial implementation of the Patlak method. Four patients had low-grade glioma (WHO II), 31 patients had glioblastoma (WHO IV) and eight patients had intracerebral lymphoma. Tumour regions of interest (ROIs) were drawn in a morphological image and automatically transferred to maps of cerebral blood flow (CBF), cerebral blood volume (CBV) and permeability (K {sup Trans}). Mean values were calculated, group differences were tested using Wilcoxon and Mann Whitney U-tests. In comparison with normal parenchyma, low-grade gliomas showed no significant difference of perfusion parameters (p > 0.05), whereas high-grade gliomas demonstrated significantly higher values (p < 0.0001 for K {sup Trans}, p < 0.0001 for CBV and p = 0.0002 for CBF). Lymphomas displayed significantly increased mean K{sup Trans} values compared with unaffected cerebral parenchyma (p = 0.0078) but no elevation of CBV. High-grade gliomas show significant higher CBV values than lymphomas (p = 0.0078). PCT allows to reliably classify gliomas and lymphomas based on quantitative measurements of CBV and K {sup Trans}. (orig.)

  15. Venous infraction of developmental venous anomaly: A case report with perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Youn; Kim, Hye Jeong; Hyun, Su Jeong; Kim, Hee Yeong; Kim, Han Myun; Hwang, Ji Young; Hong, Hye Suk; Woo, Ji Young; Yang, Ik [Dept. of Radiology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of); Kim, Eun Soo [Dept. of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2017-06-15

    Developmental venous anomaly (DVA) is a common congenital venous malformation characterized by dilated medullary veins in caput medusa configuration and a draining vein. Despite the high incidence of DVAs, they are benign anatomic variations and rarely cause symptoms. Here, we report computed tomography and magnetic resonance imaging findings with perfusion images of acute infarction from underlying DVA in a 63-year-old female patient who presented with acute onset of neurologic symptoms and recovered without any neurologic deficit.

  16. Quantitative Measurements using Ultrasound Vector Flow Imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2016-01-01

    Duplex Vector Flow Imaging (VFI) imaging is introduced as a replacement for spectral Doppler, as it automatically can yield fully quantitative flow estimates without angle correction. Continuous VFI data over 9 s for 10 pulse cycles were acquired by a 3 MHz convex probe connected to the SARUS......L/stroke (true: 1.15 mL/stroke, bias: 12.2%). Measurements down to 160 mm were obtained with a relative standard deviation and bias of less than 10% for the lateral component for stationary, parabolic flow. The method can, thus, find quantitative velocities, angles, and volume flows at sites currently...

  17. Quantitative Imaging with a Mobile Phone Microscope

    Science.gov (United States)

    Skandarajah, Arunan; Reber, Clay D.; Switz, Neil A.; Fletcher, Daniel A.

    2014-01-01

    Use of optical imaging for medical and scientific applications requires accurate quantification of features such as object size, color, and brightness. High pixel density cameras available on modern mobile phones have made photography simple and convenient for consumer applications; however, the camera hardware and software that enables this simplicity can present a barrier to accurate quantification of image data. This issue is exacerbated by automated settings, proprietary image processing algorithms, rapid phone evolution, and the diversity of manufacturers. If mobile phone cameras are to live up to their potential to increase access to healthcare in low-resource settings, limitations of mobile phone–based imaging must be fully understood and addressed with procedures that minimize their effects on image quantification. Here we focus on microscopic optical imaging using a custom mobile phone microscope that is compatible with phones from multiple manufacturers. We demonstrate that quantitative microscopy with micron-scale spatial resolution can be carried out with multiple phones and that image linearity, distortion, and color can be corrected as needed. Using all versions of the iPhone and a selection of Android phones released between 2007 and 2012, we show that phones with greater than 5 MP are capable of nearly diffraction-limited resolution over a broad range of magnifications, including those relevant for single cell imaging. We find that automatic focus, exposure, and color gain standard on mobile phones can degrade image resolution and reduce accuracy of color capture if uncorrected, and we devise procedures to avoid these barriers to quantitative imaging. By accommodating the differences between mobile phone cameras and the scientific cameras, mobile phone microscopes can be reliably used to increase access to quantitative imaging for a variety of medical and scientific applications. PMID:24824072

  18. Quantitative imaging with a mobile phone microscope.

    Directory of Open Access Journals (Sweden)

    Arunan Skandarajah

    Full Text Available Use of optical imaging for medical and scientific applications requires accurate quantification of features such as object size, color, and brightness. High pixel density cameras available on modern mobile phones have made photography simple and convenient for consumer applications; however, the camera hardware and software that enables this simplicity can present a barrier to accurate quantification of image data. This issue is exacerbated by automated settings, proprietary image processing algorithms, rapid phone evolution, and the diversity of manufacturers. If mobile phone cameras are to live up to their potential to increase access to healthcare in low-resource settings, limitations of mobile phone-based imaging must be fully understood and addressed with procedures that minimize their effects on image quantification. Here we focus on microscopic optical imaging using a custom mobile phone microscope that is compatible with phones from multiple manufacturers. We demonstrate that quantitative microscopy with micron-scale spatial resolution can be carried out with multiple phones and that image linearity, distortion, and color can be corrected as needed. Using all versions of the iPhone and a selection of Android phones released between 2007 and 2012, we show that phones with greater than 5 MP are capable of nearly diffraction-limited resolution over a broad range of magnifications, including those relevant for single cell imaging. We find that automatic focus, exposure, and color gain standard on mobile phones can degrade image resolution and reduce accuracy of color capture if uncorrected, and we devise procedures to avoid these barriers to quantitative imaging. By accommodating the differences between mobile phone cameras and the scientific cameras, mobile phone microscopes can be reliably used to increase access to quantitative imaging for a variety of medical and scientific applications.

  19. Design of a digital phantom population for myocardial perfusion SPECT imaging research

    Science.gov (United States)

    Ghaly, Michael; Du, Yong; Fung, George S. K.; Tsui, Benjamin M. W.; Links, Jonathan M.; Frey, Eric

    2014-06-01

    Digital phantoms and Monte Carlo (MC) simulations have become important tools for optimizing and evaluating instrumentation, acquisition and processing methods for myocardial perfusion SPECT (MPS). In this work, we designed a new adult digital phantom population and generated corresponding Tc-99m and Tl-201 projections for use in MPS research. The population is based on the three-dimensional XCAT phantom with organ parameters sampled from the Emory PET Torso Model Database. Phantoms included three variations each in body size, heart size, and subcutaneous adipose tissue level, for a total of 27 phantoms of each gender. The SimSET MC code and angular response functions were used to model interactions in the body and the collimator-detector system, respectively. We divided each phantom into seven organs, each simulated separately, allowing use of post-simulation summing to efficiently model uptake variations. Also, we adapted and used a criterion based on the relative Poisson effective count level to determine the required number of simulated photons for each simulated organ. This technique provided a quantitative estimate of the true noise in the simulated projection data, including residual MC simulation noise. Projections were generated in 1 keV wide energy windows from 48-184 keV assuming perfect energy resolution to permit study of the effects of window width, energy resolution, and crosstalk in the context of dual isotope MPS. We have developed a comprehensive method for efficiently simulating realistic projections for a realistic population of phantoms in the context of MPS imaging. The new phantom population and realistic database of simulated projections will be useful in performing mathematical and human observer studies to evaluate various acquisition and processing methods such as optimizing the energy window width, investigating the effect of energy resolution on image quality and evaluating compensation methods for degrading factors such as crosstalk in

  20. Quantitative imaging of bilirubin by photoacoustic microscopy

    Science.gov (United States)

    Zhou, Yong; Zhang, Chi; Yao, Da-Kang; Wang, Lihong V.

    2013-03-01

    Noninvasive detection of both bilirubin concentration and its distribution is important for disease diagnosis. Here we implemented photoacoustic microscopy (PAM) to detect bilirubin distribution. We first demonstrate that our PAM system can measure the absorption spectra of bilirubin and blood. We also image bilirubin distributions in tissuemimicking samples, both without and with blood mixed. Our results show that PAM has the potential to quantitatively image bilirubin in vivo for clinical applications.

  1. Quantitative image processing in fluid mechanics

    Science.gov (United States)

    Hesselink, Lambertus; Helman, James; Ning, Paul

    1992-01-01

    The current status of digital image processing in fluid flow research is reviewed. In particular, attention is given to a comprehensive approach to the extraction of quantitative data from multivariate databases and examples of recent developments. The discussion covers numerical simulations and experiments, data processing, generation and dissemination of knowledge, traditional image processing, hybrid processing, fluid flow vector field topology, and isosurface analysis using Marching Cubes.

  2. Perfusion parameters of dynamic contrast-enhanced magnetic resonance imaging in patients with rectal cancer: Correlation with microvascular density and vascular endothelial growth factor expression

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeo Eun [Dept. of Radiology, Seoul Medical Center, Seoul (Korea, Republic of); Lim, Joon Seok; Kim, Myeong Jin; Kim, Ki Whang; Choi, Jun Jeong [Yonsei University Health System, Seoul (Korea, Republic of); Kim, Dae Hong [Molecular Imaging and Therapy Branch, National Cancer Center, Goyang (Korea, Republic of); Myoung, Sung Min [Dept. of Medical Information, Jungwon University, Goesan (Korea, Republic of)

    2013-12-15

    To determine whether quantitative perfusion parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) correlate with immunohistochemical markers of angiogenesis in rectal cancer. Preoperative DCE-MRI was performed in 63 patients with rectal adenocarcinoma. Transendothelial volume transfer (K{sup trans}) and fractional volume of the extravascular-extracellular space (Ve) were measured by Interactive Data Language software in rectal cancer. After surgery, microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression scores were determined using immunohistochemical staining of rectal cancer specimens. Perfusion parameters (K{sup trans}, Ve) of DCE-MRI in rectal cancer were found to be correlated with MVD and VEGF expression scores by Spearman's rank coefficient analysis. T stage and N stage (negative or positive) were correlated with perfusion parameters and MVD. Significant correlation was not found between any DCE-MRI perfusion parameters and MVD (rs = -0.056 and p 0.662 for K{sup trans}; rs = -0.103 and p = 0.416 for Ve), or between any DCE-MRI perfusion parameters and the VEGF expression score (rs = -0.042, p 0.741 for K{sup trans}; r = 0.086, p = 0.497 for Ve) in rectal cancer. TN stage showed no significant correlation with perfusion parameters or MVD (p > 0.05 for all). DCE-MRI perfusion parameters, K{sup trans} and Ve, correlated poorly with MVD and VEGF expression scores in rectal cancer, suggesting that these parameters do not simply denote static histological vascular properties.

  3. The low attenuation area on dual-energy perfusion CT: Correlation with the pulmonary function tests and quantitative CT measurements

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine (Japan); Kunihiro, Yoshie; Nakashima, Yoshiteru; Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine (Japan); Sano, Yuichi; Yuasa, Yuuki; Narazaki, Akiko; Kudomi, Shohei; Koike, Masahiro [Department of Radiology, Yamaguchi University Hospital (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University (Japan)

    2012-10-15

    Purpose: To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements. Materials and methods: Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval. The ranges of the LAA on DEpCT were classified into six groups with attenuation values of 0–3, 0–5, 0–8, 0–10, 0–13 and 0–15 HU and the ratios of LAA in each group were compared with the percentage of forced expiratory volume in the 1st second (%FEV{sub 1.0}), FEV{sub 1.0}/forced vital capacity (FEV{sub 1.0}/FVC) and the relative area of the lung with attenuation coefficients lower than −950 HU (RA{sub −950}). Results: The LAAs on the DEpCT images were significantly correlated with the RA{sub −950}, %FEV{sub 1.0} and FEV{sub 1.0}/FVC, and the regression analysis showed that the best values of LAA on DEpCT were 0–10 HU with RA{sub −950} (r = 0.63), 0–8 HU with %FEV{sub 1.0} (r = −0.52) and 0–8 HU with FEV{sub 1.0}/FVC (r = −0.61) per patient. Conclusion: The iodine disturbance on DEpCT had a moderate correlation with the results of the PFTs and RA{sub −950}, but further examination would be needed for evaluation of iodine distribution.

  4. Perfusion of burn wounds assessed by Laser Doppler Imaging is related to burn depth and healing time

    NARCIS (Netherlands)

    Kloppenberg, FWH; Beerthuizen, GIJM; ten Duis, HJ

    Average perfusion in various burn wounds was assessed using Laser Doppler Imaging (LDI). The time necessary for a complete healing of the wound was compared to the results of the LDI measurements. A certain depth of burn was associated with a typical pattern of perfusion in the course of time. There

  5. Perfusion of burn wounds assessed by Laser Doppler Imaging is related to burn depth and healing time

    NARCIS (Netherlands)

    Kloppenberg, FWH; Beerthuizen, GIJM; ten Duis, HJ

    2001-01-01

    Average perfusion in various burn wounds was assessed using Laser Doppler Imaging (LDI). The time necessary for a complete healing of the wound was compared to the results of the LDI measurements. A certain depth of burn was associated with a typical pattern of perfusion in the course of time. There

  6. PCA-based groupwise image registration for quantitative MRI.

    Science.gov (United States)

    Huizinga, W; Poot, D H J; Guyader, J-M; Klaassen, R; Coolen, B F; van Kranenburg, M; van Geuns, R J M; Uitterdijk, A; Polfliet, M; Vandemeulebroucke, J; Leemans, A; Niessen, W J; Klein, S

    2016-04-01

    Quantitative magnetic resonance imaging (qMRI) is a technique for estimating quantitative tissue properties, such as the T1 and T2 relaxation times, apparent diffusion coefficient (ADC), and various perfusion measures. This estimation is achieved by acquiring multiple images with different acquisition parameters (or at multiple time points after injection of a contrast agent) and by fitting a qMRI signal model to the image intensities. Image registration is often necessary to compensate for misalignments due to subject motion and/or geometric distortions caused by the acquisition. However, large differences in image appearance make accurate image registration challenging. In this work, we propose a groupwise image registration method for compensating misalignment in qMRI. The groupwise formulation of the method eliminates the requirement of choosing a reference image, thus avoiding a registration bias. The method minimizes a cost function that is based on principal component analysis (PCA), exploiting the fact that intensity changes in qMRI can be described by a low-dimensional signal model, but not requiring knowledge on the specific acquisition model. The method was evaluated on 4D CT data of the lungs, and both real and synthetic images of five different qMRI applications: T1 mapping in a porcine heart, combined T1 and T2 mapping in carotid arteries, ADC mapping in the abdomen, diffusion tensor mapping in the brain, and dynamic contrast-enhanced mapping in the abdomen. Each application is based on a different acquisition model. The method is compared to a mutual information-based pairwise registration method and four other state-of-the-art groupwise registration methods. Registration accuracy is evaluated in terms of the precision of the estimated qMRI parameters, overlap of segmented structures, distance between corresponding landmarks, and smoothness of the deformation. In all qMRI applications the proposed method performed better than or equally well as

  7. Brain perfusion imaging using a Reconstruction-of-Difference (RoD) approach for cone-beam computed tomography

    Science.gov (United States)

    Mow, M.; Zbijewski, W.; Sisniega, A.; Xu, J.; Dang, H.; Stayman, J. W.; Wang, X.; Foos, D. H.; Koliatsos, V.; Aygun, N.; Siewerdsen, J. H.

    2017-03-01

    Purpose: To improve the timely detection and treatment of intracranial hemorrhage or ischemic stroke, recent efforts include the development of cone-beam CT (CBCT) systems for perfusion imaging and new approaches to estimate perfusion parameters despite slow rotation speeds compared to multi-detector CT (MDCT) systems. This work describes development of a brain perfusion CBCT method using a reconstruction of difference (RoD) approach to enable perfusion imaging on a newly developed CBCT head scanner prototype. Methods: A new reconstruction approach using RoD with a penalized-likelihood framework was developed to image the temporal dynamics of vascular enhancement. A digital perfusion simulation was developed to give a realistic representation of brain anatomy, artifacts, noise, scanner characteristics, and hemo-dynamic properties. This simulation includes a digital brain phantom, time-attenuation curves and noise parameters, a novel forward projection method for improved computational efficiency, and perfusion parameter calculation. Results: Our results show the feasibility of estimating perfusion parameters from a set of images reconstructed from slow scans, sparse data sets, and arc length scans as short as 60 degrees. The RoD framework significantly reduces noise and time-varying artifacts from inconsistent projections. Proper regularization and the use of overlapping reconstructed arcs can potentially further decrease bias and increase temporal resolution, respectively. Conclusions: A digital brain perfusion simulation with RoD imaging approach has been developed and supports the feasibility of using a CBCT head scanner for perfusion imaging. Future work will include testing with data acquired using a 3D-printed perfusion phantom currently and translation to preclinical and clinical studies.

  8. Examining a hypothetical quantitative model for better approximation of culprit coronary artery and site of stenosis on 99mTc-sestamibi gated myocardial perfusion SPECT.

    Science.gov (United States)

    Pal, Sushanta; Sen, Srabani; Das, Debasis; Basu, Sandip

    2016-10-01

    A hypothetical quantitative model of analyzing gated myocardial perfusion SPECT is proposed and examined for the feasibility of its use as a predictor of diseased coronary artery and approximating the site of stenosis to determine whether it could serve as a useful noninvasive complement for coronary angiography. The extent and severity of perfusion defects on rest gated myocardial perfusion imaging SPECT-images were assessed on a five-point scale in a standard 17-segment model and total perfusion deficit was quantified by automated software. The first step was to locate the diseased coronary artery using a quantitative method: for this, the score of each segment belonging to a particular coronary artery was determined using a systematic presumptive approach. After determination of specific coronary artery segments, the scores of the contiguous segments in three short axis slices (apical, middle, and basal) were summed for six subdivisions (anterior, anterolateral, inferolateral, inferior, anteroseptal, and inferoseptal). The site of stenosis was determined from (a) the initial approximation of the involved segments with a defect score of 2-4 and (b) subsequent calculation of the defect score of each of the six subdivisions and allocating the site through a preassigned number for each coronary artery. For each coronary artery, only the subdivision with the highest defect score was considered. Proximal, middle, and distal segments of left anterior descending artery (LAD) were considered to be represented when the summed value of a subdivision within a particular arterial territory was more than or equal to 7, between 5 and 7, 5 and 3, respectively. For the left circumflex and right coronary artery, summed scores (of respective subdivisions) of more than or equal to 5 and between 3 and 5 were preassigned to proximal and distal stenosis, respectively. The results were then correlated with the coronary angiographic data. On coronary angiography, proximal LAD occlusion

  9. Quantitative Techniques in PET-CT Imaging

    NARCIS (Netherlands)

    Basu, Sandip; Zaidi, Habib; Holm, Soren; Alavi, Abass

    2011-01-01

    The appearance of hybrid PET/CT scanners has made quantitative whole body scanning of radioactive tracers feasible. This paper deals with the novel concepts for assessing global organ function and disease activity based on combined functional (PET) and structural (CT or MR) imaging techniques, their

  10. Cerebral perfusion semi-quantitative imaging for assessing the treatment of delayed encephalopathy from carbon monoxide poisoning%脑血流灌注半定量法显像评价高压氧联合药物治疗一氧化碳中毒迟发性脑病疗效

    Institute of Scientific and Technical Information of China (English)

    熊冰; 周游; 蔡亚利; 刘洪彪; 汤中泉; 孙达; 徐昕; 刘文明

    2009-01-01

    目的 对比研究一氧化碳中毒后迟发性脑病(DEACMP)患者在高压氧(HBO)联合药物治疗前、后单光子发射计算机断层成像(SPECT)脑血流灌注显像结果,并对其优越性及临床意义进行评价.方法 34例DEACMP患者接受20~40次HBO联合药物治疗,并在治疗前、后用双半胱乙酯(~(99m)Tc-ECD)脑SPECT血流灌注扫描半定量法进行疗效监测和对比分析.结果 HBO治疗后,DEACMP患者脑血流灌注减低区有明显改善,脑SPECT血流灌注半定量值与治疗前比较,差异有统计学意义(P<0.05),而治疗前、后脑磁共振显像无明显差异.结论 脑SPECT血流灌注半定量法显像在DEACMP的诊断和HBO治疗的疗效监测中可起重要作用.%Objective To evaluate the effects of hyperbaric oxygen (HBO) combined with drug therapy on patients with delayed encephalopathy caused by carbon monoxide poisoning ( COP). Methods Twenty to forty sessions of HBO therapy were used to treat 34 COP patients. Assessment relied on 99mTc-ethyl cysteinate dimer (~(99m)Tc-ECD) single photon emission computed tomography (SPECT) imaging of cerebral perfusion before and after treatment. Results After HBO therapy, cerebral perfusion in the COP patients improved significantly. There was a significant difference of the SPECT images before and after treatment. Conclusions SPECT imaging of cerebral perfusion can play an important role in the diagnosis of delayed encephalopathy caused by carbon monoxide poisoning, and it can be used for the therapeutic surveillance of HBO treatment.

  11. Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael A.; Kartalis, Nikolaos; Aspelin, Peter; Albiin, Nils; Brismar, Torkel B. [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Leidner, Bertil; Svensson, Anders [Karolinska University Hospital, Division of Medical Imaging and Technology, Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm (Sweden); Karolinska University Hospital Huddinge, Department of Radiology, Stockholm (Sweden)

    2014-01-15

    To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. (orig.)

  12. Assessing the utility of the ventilation phase in ventilation-perfusion imaging for acute pulmonary embolism.

    Science.gov (United States)

    Grimm, Lars J; Coleman, Ralph E

    2013-01-01

    This study aims to identify patient characteristics that allow the exclusion of the ventilation phase in ventilation-perfusion imaging for the evaluation of acute pulmonary embolism (PE). A total of 500 consecutive ventilation-perfusion reports with an indication for possible acute PE were retrospectively reviewed. Information on ventilation abnormalities, perfusion defects, PIOPED classification, age, sex, chest radiograph results, and presence of respiratory disease was recorded. Patients with moderate and large perfusion defects were analyzed to assess the utility of the ventilation phase on the final PIOPED classification. Moderate (n=39) or large (n=26) perfusion defects were seen in 65 (13%) studies. Of these, 46 studies (70.8%) had defects unmatched on ventilation and three (4.6%) had triple-match defects, resulting in 49 reports (75.4%) classified as intermediate (n=28) or high (n=21) probability for PE. There was a statistically significant association between unmatched defects and a clear chest radiograph (P=0.03) and an association approaching statistical significance with younger age (P=0.05). There was a strong association with respiratory disease (P=0.12) and no association with patient sex (P=0.82). The percentage of studies with unmatched defects increased from 70.8 to 76.7% (33/43, P=0.39) if patients with respiratory disease were excluded, to 82.4% (28/34, P=0.14) if abnormal chest radiographs were excluded, and to 95.7% (22/23, P=0.01) if both were excluded. There may be a subset of patients - younger patients with clear chest radiographs and no respiratory disease - for whom the ventilation phase can be excluded and the determination of a PE is based solely on perfusion abnormalities.

  13. Quantitative imaging features: extension of the oncology medical image database

    Science.gov (United States)

    Patel, M. N.; Looney, P. T.; Young, K. C.; Halling-Brown, M. D.

    2015-03-01

    Radiological imaging is fundamental within the healthcare industry and has become routinely adopted for diagnosis, disease monitoring and treatment planning. With the advent of digital imaging modalities and the rapid growth in both diagnostic and therapeutic imaging, the ability to be able to harness this large influx of data is of paramount importance. The Oncology Medical Image Database (OMI-DB) was created to provide a centralized, fully annotated dataset for research. The database contains both processed and unprocessed images, associated data, and annotations and where applicable expert determined ground truths describing features of interest. Medical imaging provides the ability to detect and localize many changes that are important to determine whether a disease is present or a therapy is effective by depicting alterations in anatomic, physiologic, biochemical or molecular processes. Quantitative imaging features are sensitive, specific, accurate and reproducible imaging measures of these changes. Here, we describe an extension to the OMI-DB whereby a range of imaging features and descriptors are pre-calculated using a high throughput approach. The ability to calculate multiple imaging features and data from the acquired images would be valuable and facilitate further research applications investigating detection, prognosis, and classification. The resultant data store contains more than 10 million quantitative features as well as features derived from CAD predictions. Theses data can be used to build predictive models to aid image classification, treatment response assessment as well as to identify prognostic imaging biomarkers.

  14. Real-time breath-hold triggering of myocardial perfusion imaging with a novel cadmium-zinc-telluride detector gamma camera

    Energy Technology Data Exchange (ETDEWEB)

    Buechel, Ronny R.; Pazhenkottil, Aju P.; Herzog, Bernhard A.; Husmann, Lars; Nkoulou, Rene N.; Burger, Irene A.; Valenta, Ines; Wyss, Christophe A.; Ghadri, Jelena R. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology (ZIHP), Zurich (Switzerland)

    2010-10-15

    The aim of this study was to assess the ability of real-time breath-hold-triggered myocardial perfusion imaging (MPI) using a novel cadmium-zinc-telluride (CZT) gamma camera to discriminate artefacts from true perfusion defects. A group of 40 patients underwent a 1-day {sup 99m}Tc-tetrofosmin pharmacological stress/rest imaging protocol on a conventional dual detector SPECT gamma camera with and without attenuation correction (AC), immediately followed by scanning on an ultrafast CZT camera with and without real-time breath-hold triggering (instead of AC) by intermittent scanning confined to breath-hold at deep inspiration (using list mode acquisition). We studied the use of breath-hold triggering on the CZT camera and its ability to discriminate artefacts from true perfusion defects using AC SPECT MPI as the reference standard. Myocardial tracer uptake (percent of maximum) from CZT was compared to AC SPECT MPI by intraclass correlation and by calculating Bland-Altman limits of agreement. AC of SPECT MPI identified 19 apparent perfusion defects as artefacts. Of these, 13 were correctly identified and 4 were partially unmasked (decrease in extent and/or severity) by breath-hold triggering of the CZT scan. All perfusion defects verified by SPECT MPI with AC were appropriately documented by CZT with and without breath-hold triggering. This was supported by the quantitative analysis, as the correlation (r) of myocardial tracer uptake between CZT and AC SPECT improved significantly from 0.81 to 0.90 (p<0.001) when applying breath-hold triggering. Similarly, Bland-Altman limits of agreement were narrower for CZT scans with breath-hold triggering. This novel CZT camera allows real-time breath-hold triggering as a potential alternative to AC to assist in the discrimination of artefacts from true perfusion defects. (orig.)

  15. Four dimensional optoacoustic imaging of perfusion in preclinical breast tumor model in vivo (Conference Presentation)

    Science.gov (United States)

    Deán-Ben, Xosé Luís.; Ermolayev, Vladimir; Mandal, Subhamoy; Ntziachristos, Vasilis; Razansky, Daniel

    2016-03-01

    Imaging plays an increasingly important role in clinical management and preclinical studies of cancer. Application of optical molecular imaging technologies, in combination with highly specific contrast agent approaches, eminently contributed to understanding of functional and histological properties of tumors and anticancer therapies. Yet, optical imaging exhibits deterioration in spatial resolution and other performance metrics due to light scattering in deep living tissues. High resolution molecular imaging at the whole-organ or whole-body scale may therefore bring additional understanding of vascular networks, blood perfusion and microenvironment gradients of malignancies. In this work, we constructed a volumetric multispectral optoacoustic tomography (vMSOT) scanner for cancer imaging in preclinical models and explored its capacity for real-time 3D intravital imaging of whole breast cancer allografts in mice. Intrinsic tissue properties, such as blood oxygenation gradients, along with the distribution of externally administered liposomes carrying clinically-approved indocyanine green dye (lipo-ICG) were visualized in order to study vascularization, probe penetration and extravasation kinetics in different regions of interest within solid tumors. The use of v-MSOT along with the application of volumetric image analysis and perfusion tracking tools for studies of pathophysiological processes within microenvironment gradients of solid tumors demonstrated superior volumetric imaging system performance with sustained competitive resolution and imaging depth suitable for investigations in preclinical cancer models.

  16. Three dimensional first-pass myocardial perfusion imaging at 3T: feasibility study

    Directory of Open Access Journals (Sweden)

    Pohost Gerald M

    2008-12-01

    Full Text Available Abstract Background In patients with ischemic heart disease, accurate assessment of the extent of myocardial perfusion deficit may be important in predicting prognosis of clinical cardiac outcomes. The aim of this study was to compare the ability of three dimensional (3D and of two dimensional (2D multi-slice myocardial perfusion imaging (MPI using cardiovascular magnetic resonance (CMR in determining the size of defects, and to demonstrate the feasibility of 3D MPI in healthy volunteers at 3 Tesla. Methods A heart phantom was used to compare the accuracy of 3D and 2D multi-slice MPI in estimating the volume fraction of seven rubber insets which simulated transmural myocardial perfusion defects. Three sets of cross-sectional planes were acquired for 2D multi-slice imaging, where each set was shifted along the partition encoding direction by ± 10 mm. 3D first-pass contrast-enhanced (0.1 mmol/kg Gd-DTPA MPI was performed in three volunteers with sensitivity encoding for six-fold acceleration. The upslope of the myocardial time-intensity-curve and peak SNR/CNR values were calculated. Results Mean/standard deviation of errors in estimating the volume fraction across the seven defects were -0.44/1.49%, 2.23/2.97%, and 2.59/3.18% in 3D, 2D 4-slice, and 2D 3-slice imaging, respectively. 3D MPI performed in healthy volunteers produced excellent quality images with whole left ventricular (LV coverage. Peak SNR/CNR was 57.6 ± 22.0/37.5 ± 19.7 over all segments in the first eight slices. Conclusion 3D performed better than 2D multi-slice MPI in estimating the size of perfusion defects in phantoms. Highly accelerated 3D MPI at 3T was feasible in volunteers, allowing whole LV coverage with excellent image quality and high SNR/CNR.

  17. 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.

  18. Experimental system for perfusion imaging and time-intensity processing based on ultrasound contrast agent

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To present a self-developed experimental system for basic studies of blood perfusion imaging and time-intensity evaluating based on ultrasound contrast agent. Methods: The experimental system performed the image reconstruction and time-intensity processing with radio frequency signals. The system was comprised of ultra-high speed hardware data acquisition interface and low computational cost algorithms. The self-made contrast agent ,blood mimic phantom and capillary phantom model were used to validate the experimental system. Results: The images acquired in blood phantoms with linear-array and curve-array transducers were given. The time-intensity curves corresponding to selected region of interested from image sequence were demonstrated. It was also shown the time-intensity based decay curves and a comparison of decay of ultrasound contrast agent under different ultrasound powers. Conclusion: Several experiments resulted from two in vitro phantom models show that the experimental system can be used to basic studies of blood perfusion and further clinical studies of microvasculature perfusion.

  19. 3D imaging of myocardial perfusion and coronary tree morphology from a single rotational angiogram

    Science.gov (United States)

    Lauritsch, Günter; Rohkohl, Christopher; Hornegger, Joachim; Sinha, Anil-Martin; Brachmann, Johannes; Rieber, Johannes; Rittger, Harald

    2011-03-01

    Diagnosis and treatment of coronary heart disease are performed in the catheter laboratory using an angiographic X-ray C-arm system. The morphology of the coronary tree and potentially ischemic lesions are determined in 2D projection views. The hemodynamic impact of the lesion would be valuable information for treatment decision. Using other modalities for functional imaging is disrupting the clinical workflow since the patient has to be transferred from the catheter laboratory to another scanner, and back to the catheter laboratory for performing the treatment. In this work a novel technology is used for simultaneous 3D imaging of first pass perfusion and the morphology of the coronary tree from a single rotational angiogram. A selective, single shot of contrast agent of less than 20ml directly into the coronaries is sufficient for a proper contrast resolution. Due to the long acquisition time cardiac motion has to be considered. A novel reconstruction technique for estimation and compensation of cardiac motion from the acquired projection data is used. The overlay of the 3D structure of the coronary tree and the perfusion image shows the correlation of myocardial areas and the associated coronary sections supporting that region. In a case example scar lesions caused by a former myocardial infarct are investigated. A first pass perfusion defect is found which is validated by a late enhancement magnetic resonance image. No ischemic defects are found. The non vital regions are still supported by the coronary vasculature.

  20. 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 reviews...... 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...

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

    Science.gov (United States)

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

    2013-05-01

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

  2. Assessing photoplethysmographic imaging performance beyond facial perfusion analysis

    Science.gov (United States)

    Amelard, Robert; Hughson, Richard L.; Greaves, Danielle K.; Clausi, David A.; Wong, Alexander

    2017-02-01

    Photoplethysmographic imaging (PPGI) systems are relatively new non-contact biophotonic diffuse reflectance systems able to assess arterial pulsations through transient changes in light-tissue interaction. Many PPGI studies have focused on extracting heart rate from the face or hand. Though PPGI systems can be used for widefield imaging of any anatomical area, whole-body investigations are lacking. Here, using a novel PPGI system, coded hemodynamic imaging (CHI), we explored and analyzed the pulsatility at major arterial locations across the whole body, including the neck (carotid artery), arm/wrist (brachial, radial and ulnar arteries), and leg/feet (popliteal and tibial arteries). CHI was positioned 1.5 m from the participant, and diffuse reactance from a broadband tungsten-halogen illumination was filtered using 850{1000 nm bandpass filter for deep tissue penetration. Images were acquired over a highly varying 24-participant sample (11/13 female/male, age 28.7+/-12.4 years, BMI 25.5+/-5.2 kg/m2), and a preliminary case study was performed. B-mode ultrasound images were acquired to validate observations through planar arterial characteristics.

  3. 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.)

  4. Portable laser speckle perfusion imaging system based on digital signal processor.

    Science.gov (United States)

    Tang, Xuejun; Feng, Nengyun; Sun, Xiaoli; Li, Pengcheng; Luo, Qingming

    2010-12-01

    The ability to monitor blood flow in vivo is of major importance in clinical diagnosis and in basic researches of life science. As a noninvasive full-field technique without the need of scanning, laser speckle contrast imaging (LSCI) is widely used to study blood flow with high spatial and temporal resolution. Current LSCI systems are based on personal computers for image processing with large size, which potentially limit the widespread clinical utility. The need for portable laser speckle contrast imaging system that does not compromise processing efficiency is crucial in clinical diagnosis. However, the processing of laser speckle contrast images is time-consuming due to the heavy calculation for enormous high-resolution image data. To address this problem, a portable laser speckle perfusion imaging system based on digital signal processor (DSP) and the algorithm which is suitable for DSP is described. With highly integrated DSP and the algorithm, we have markedly reduced the size and weight of the system as well as its energy consumption while preserving the high processing speed. In vivo experiments demonstrate that our portable laser speckle perfusion imaging system can obtain blood flow images at 25 frames per second with the resolution of 640 × 480 pixels. The portable and lightweight features make it capable of being adapted to a wide variety of application areas such as research laboratory, operating room, ambulance, and even disaster site.

  5. 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.

  6. Perfusion and metabolism imaging studies in Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, Per

    2012-01-01

    Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are important tools in the evaluation of brain blood flow and glucose metabolism in Parkinson's disease (PD). However, conflicting results are reported in the literature depending on the type of imaging data...

  7. Image Based Calculation of Perfusion and Oxyhemoglobin Saturation in Skeletal Muscle during Submaximal Isometric Contractions

    Science.gov (United States)

    Elder, Christopher P.; Cook, Ryan N.; Chance, Marti A.; Copenhaver, Elizabeth A.; Damon, Bruce M.

    2015-01-01

    The relative oxygen saturation of hemoglobin (%HbO2) and the rate of perfusion (θ̇) are important physiological quantities, particularly in organs such as skeletal muscle in which oxygen delivery and use are tightly coupled. The purpose of this study was to demonstrate the image-based calculation of %HbO2 and quantification of perfusion in skeletal muscle during isometric contractions. This was accomplished by establishing an empirical relationship between the rate of RF-reversible dephasing (R2′) and near infrared spectroscopy (NIRS)-observed oxyhemoglobin saturation (%HbO2) under conditions of arterial occlusion and constant blood volume. A calibration curve was generated and used to calculate %HbO2 from R2′ changes measured during contraction. Twelve young healthy subjects underwent 300 seconds of arterial occlusion and performed isometric contractions of the dorsiflexors at 30% of maximal contraction for 120s. Muscle perfusion was quantified during contraction by arterial spin labeling and measures of muscle T1. Comparisons between the %HbO2 values predicted from R2′ and that measured by NIRS revealed no differences between methods (p = 0.760). Muscle perfusion reached a value of 34.7 mL 100g−1 min−1 during contraction. These measurements hold future promise in measuring muscle oxygen consumption in healthy and diseased skeletal muscle. PMID:20806379

  8. Reverse Redistribution in Myocardial Perfusion Imaging: Revisited with 64-slice MDCT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Kyung; Kim, Jeong Ho; Hwang, Kyung Hoon; Choi, In Suck; Choi, Soo Jin; Choe, Won Sick [Gachon University Gil Hospital, Incheon (Korea, Republic of); Yoon, Min Ki [Good Samaritan Hospital, Pohang (Korea, Republic of)

    2010-06-15

    The authors report myocardial perfusion imaging of a patient showing reverse redistribution (RR) and a 64-slice multidetector-row computed tomography (MDCT) with corresponding findings. The patient had subendocardial myocardial infarction (MI) with positive electrocardiogram (EMG) findings and elevated levels of cardiac isoenzymes. Experiencing this case emphasizes the importance of complementary correlation of a new diagnostic modality that helps us to understand the nature of RR.

  9. Chordoid glioma with intraventricular dissemination: A case report with perfusion MR imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Ki, So Yeon; Kim, Seul Kee; Heo, Tae Wook; Baek, Byung Hyun; Kim, Hyung Seok; Yoon, Woong [Chonnam National University Medical School, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2016-02-15

    Chordoid glioma is a rare low grade tumor typically located in the third ventricle. Although a chordoid glioma can arise from ventricle with tumor cells having features of ependymal differentiation, intraventricular dissemination has not been reported. Here we report a case of a patient with third ventricular chordoid glioma and intraventricular dissemination in the lateral and fourth ventricles. We described the perfusion MR imaging features of our case different from a previous report.

  10. Lung or liver: An imaging dilemma on Tc-99m macroaggregated albumin lung perfusion scintigraphy

    OpenAIRE

    Jain, Tarun Kumar; Phulsunga, Rohit Kumar; Kumar, Sunil; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2015-01-01

    We present a 10-year-old boy having the bronchiectasis who was subjected to lung perfusion scintigraphy before lung resection surgery to assess the lung parenchymal function. It revealed unusual tracer distribution in right upper body that was mimicking to be liver. It was unusual unless there were some shunts bypassing the lung uptake or faulty radiopharmaceutical preparation. However by bringing down the image window, it became clear that radiopharmaceutical distribution was in thorax only ...

  11. Computed Tomography Perfusion Usefulness in Early Imaging Diagnosis of Herpes Simplex Virus Encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Marco de Lucas, E.; Mandly, Gonzalez A.; Gutierrez, A.; Sanchez, E.; Arnaiz, J.; Piedra, T.; Rodriguez, E.; Diez, C. [Hospital Univ. Marques de Valdecilla, Santander (Spain). Depts. of Radiology and Neurology

    2006-10-15

    An early diagnosis is crucial in herpes simplex virus encephalitis patients in order to institute acyclovir therapy and reduce mortality rates. Magnetic resonance imaging (MRI) is considered the gold standard for evaluation of these patients, but is frequently not available in the emergency setting. We report the first case of a computed tomography (CT) perfusion study that helped to establish a prompt diagnosis revealing abnormal increase of blood flow in the affected temporoparietal cortex at an early stage.

  12. Improved Perfusion MR Imaging Assessment of Intracerebral Tumor Blood Volume and Antiangiogenic Therapy Efficacy in a Rat Model with Ferumoxytol

    OpenAIRE

    Gahramanov, Seymur; Muldoon, Leslie L; Li, Xin; Neuwelt, Edward A.

    2011-01-01

    Our findings suggest that, at perfusion MR imaging, more consistent estimations of relative cerebral blood volume are provided with ferumoxytol than with gadolinium-based contrast agents regardless of the permeability of the tumor vasculature.

  13. Diagnostic Accuracy of Stress Myocardial Perfusion Imaging Compared to Invasive Coronary Angiography With Fractional Flow Reserve Meta-Analysis

    NARCIS (Netherlands)

    Takx, Richard A. P.; Blomberg, Bjorn A.; El Aidi, Hamza; Habets, Jesse; de Jong, Pim A.; Nagel, Eike; Hoffmann, Udo; Leiner, Tim

    2015-01-01

    Background-Hemodynamically significant coronary artery disease is an important indication for revascularization. Stress myocardial perfusion imaging is a noninvasive alternative to invasive fractional flow reserve for evaluating hemodynamically significant coronary artery disease. The aim was to det

  14. 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

  15. Comparative imaging of differential pulmonary blood flow in patients with congenital heart disease: magnetic resonance imaging versus lung perfusion scintigraphy.

    Science.gov (United States)

    Roman, Kevin S; Kellenberger, Christian J; Farooq, Saqba; MacGowan, Christopher K; Gilday, David L; Yoo, Shi-Joon

    2005-03-01

    Lung perfusion scintigraphy is considered the gold standard to assess differential pulmonary blood flow while magnetic resonance (MR) has been shown to be an accurate alternative in some studies. The purpose of the study was to assess the accuracy of phase contrast magnetic resonance (PC-MR) in measuring pulmonary blood flow ratio compared with lung perfusion scintigraphy in patients with complex pulmonary artery anatomy or pulmonary hypertension and to document reasons for discrepant results. We identified 25 cases of congenital heart disease between January 2000 and 2003, in whom both techniques of assessing pulmonary blood flow were performed within a 6-month period without an interim surgical or transcatheter intervention. The study group included cases with branch pulmonary artery stenosis, intracardiac shunts, single ventricle circulation, pulmonary venous anomalies and conotruncal defects. The mean age at study was 5.7 years (range 0.33-12) with a mean weight of 20.3 kg (range 6.5-53.6). The two methods were compared using a Bland-Altman analysis, and the Pearson correlation coefficient was calculated using the lung scan as the gold standard. Discrepant results were examined by reviewing the source images to elucidate reasons for error by MR. Bland-Altman analysis comparing right pulmonary artery (RPA) blood flow percentage, as measured by each modality, showed a mean difference of 1.43+/-9.8 (95% limits of agreement: -17.8, 20.6) with a correlation coefficient of r=0.84, P10%) was found with a mean difference between techniques of 17.9%. The reasons for discrepant results included MR artifacts, dephasing owing to turbulent flow, site of data acquisition and lobar lung collapse. When using PC-MR to assess pulmonary blood flow ratio, important technical errors occur in a significant proportion of patients who have abnormal pulmonary artery anatomy or pulmonary hypertension. If these technical errors are avoided, PC-MR is able to supply both anatomic and

  16. Comparative imaging of differential pulmonary blood flow in patients with congenital heart disease: magnetic resonance imaging versus lung perfusion scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Kevin S. [Hospital for Sick Children, Department of Cardiology, Toronto, ON (Canada); Kellenberger, Christian J.; Farooq, Saqba; MacGowan, Christopher K.; Gilday, David L.; Yoo, Shi-Joon [Hospital for Sick Children, Diagnostic Imaging and Radiology, Toronto, ON (Canada)

    2005-03-01

    Lung perfusion scintigraphy is considered the gold standard to assess differential pulmonary blood flow while magnetic resonance (MR) has been shown to be an accurate alternative in some studies. The purpose of the study was to assess the accuracy of phase contrast magnetic resonance (PC-MR) in measuring pulmonary blood flow ratio compared with lung perfusion scintigraphy in patients with complex pulmonary artery anatomy or pulmonary hypertension and to document reasons for discrepant results. We identified 25 cases of congenital heart disease between January 2000 and 2003, in whom both techniques of assessing pulmonary blood flow were performed within a 6-month period without an interim surgical or transcatheter intervention. The study group included cases with branch pulmonary artery stenosis, intracardiac shunts, single ventricle circulation, pulmonary venous anomalies and conotruncal defects. The mean age at study was 5.7 years (range 0.33-12) with a mean weight of 20.3 kg (range 6.5-53.6). The two methods were compared using a Bland-Altman analysis, and the Pearson correlation coefficient was calculated using the lung scan as the gold standard. Discrepant results were examined by reviewing the source images to elucidate reasons for error by MR. Bland-Altman analysis comparing right pulmonary artery (RPA) blood flow percentage, as measured by each modality, showed a mean difference of 1.43{+-}9.8 (95% limits of agreement: -17.8, 20.6) with a correlation coefficient of r=0.84, P<0.0001. In six (24%) cases a large difference (>10%) was found with a mean difference between techniques of 17.9%. The reasons for discrepant results included MR artifacts, dephasing owing to turbulent flow, site of data acquisition and lobar lung collapse. When using PC-MR to assess pulmonary blood flow ratio, important technical errors occur in a significant proportion of patients who have abnormal pulmonary artery anatomy or pulmonary hypertension. If these technical errors are

  17. Real-time ultrasound brain perfusion imaging with analysis of microbubble replenishment in acute MCA stroke.

    Science.gov (United States)

    Kern, Rolf; Diels, Anna; Pettenpohl, Johanna; Kablau, Micha; Brade, Joachim; Hennerici, Michael G; Meairs, Stephen

    2011-08-01

    Real-time ultrasound perfusion imaging (rt-UPI) allows visualization of microbubbles flowing through the cerebral microvasculature. We hypothesized that analysis of microbubble tissue replenishment would enable for characterization of perfusion deficits in acute middle cerebral artery (MCA) territory stroke. Twenty-three patients (mean age 70.2 ± 13.2 years, 9 weeks) were included. Sequential images of bubble replenishment were acquired by transcranial rt-UPI at low mechanical index immediately after microbubble destruction. Different parameters were calculated from regions of interest (ROIs): real-time time to peak (rt-TTP), rise rate (β), and plateau (A) of acoustic intensity, and A × β was used as an index of blood flow. Results were compared with diffusion-weighted and perfusion magnetic resonance imaging. Parameters of rt-UPI had lower values in ROIs of ischemic as compared with normal tissue (β=0.58 ± 0.40 versus 1.25 ± 0.83; P=0.001; A=1.44 ± 1.75 versus 2.63 ± 2.31; P=0.05; A × β=1.14 ± 2.25 versus 2.98 ± 2.70; P=0.01). Real-time time to peak was delayed in ischemic tissue (11.43 ± 2.67 versus 8.88 ± 1.66 seconds; Preplenishment correctly identifies ischemic brain tissue in acute MCA stroke.

  18. Effects of radiation dose reduction in Volume Perfusion CT imaging of acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Brockmann, Carolin; Afat, Saif; Pjontek, Rastislav; Nikobashman, Omid; Brockmann, Marc A.; Wiesmann, Martin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Yang, Zepa; Kim, Changwon [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Kim, Jong Hyo [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Suwon (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Center for Medical-IT Convergence Technology Research, Advanced Institute of Convergence Technology, Suwon (Korea, Republic of)

    2015-12-15

    To examine the influence of radiation dose reduction on image quality and sensitivity of Volume Perfusion CT (VPCT) maps regarding the detection of ischemic brain lesions. VPCT data of 20 patients with suspected ischemic stroke acquired at 80 kV and 180 mAs were included. Using realistic reduced-dose simulation, low-dose VPCT datasets with 144 mAs, 108 mAs, 72 mAs and 36 mAs (80 %, 60 %, 40 % and 20 % of the original levels) were generated, resulting in a total of 100 datasets. Perfusion maps were created and signal-to-noise-ratio (SNR) measurements were performed. Qualitative analyses were conducted by two blinded readers, who also assessed the presence/absence of ischemic lesions and scored CBV and CBF maps using a modified ASPECTS-score. SNR of all low-dose datasets were significantly lower than those of the original datasets (p <.05). All datasets down to 72 mAs (40 %) yielded sufficient image quality and high sensitivity with excellent inter-observer-agreements, whereas 36 mAs datasets (20 %) yielded poor image quality in 15 % of the cases with lower sensitivity and inter-observer-agreements. Low-dose VPCT using decreased tube currents down to 72 mAs (40 % of original radiation dose) produces sufficient perfusion maps for the detection of ischemic brain lesions. (orig.)

  19. Static Myocardial Perfusion Imaging using denoised dynamic Rb-82 PET/CT scans

    DEFF Research Database (Denmark)

    Petersen, Maiken N.M.; Hoff, Camilla; Harms, Hans

    Introduction: Relative and absolute measures of myocardial perfusion are derived from a single 82Rb PET/CT scan. However, images are inherently noising due to the short half-life of 82Rb. We have previously shown that denoising techniques can be applied to dynamic 82Rb series with excellent....... Administered 82Rb dose was 1110 MBq. Denoising using HYPR-LR or Hotelling 3D algorithms was performed as post-processing on the dynamic images series. Static series were created by summing frames from 2.5-5 min. The image data was analysed in QPET (Cedars-Sinai). Relative segmental perfusion (normalized...... and Bland-Altman analysis. Results: For HYPR-LR, a good correlation was found for relative segmental perfusion for both stress (y=1.007x+0.313, R2=0.98) and rest (y=1.007x+ 0.421, R2=0.96) scans with negative bias of -0.79±1.44 and -0.90±1.63, respectively. Correlations for SSS (R2=0.94), SRS (R2=0.92), SDS...

  20. Study on the application value of CT perfusion imaging in patients with hepatic carcinoma

    Institute of Scientific and Technical Information of China (English)

    Yu-Gang Zhou; Cheng-Zhou Yu; Xi-Qun Liu

    2016-01-01

    Objective:To research and discuss the application value of CT perfusion imaging in patients with hepatic carcinoma.Methods: A total of 47 patients with hepatic carcinoma in our hospital from Januarey 2014 to August 2015 were selected as study group; meanwhile the contemporaneous 47 patients with benign liver disease were selected as control group. Then the CT perfusion imaging parameters of hepatic carcinoma patients in control group and study group, and hepatic carcinoma patients with different types and stages in study group were respectively compared and the relationship between above indexes and hepatic carcinoma were analyzed by Logistic Analysis.Results:The BF, BV, HAI, MTT, PS and HAP levels in study group were all higher than that in control group, while the PVP level was lower than that in control group, and the detection results between hepatic carcinoma patients with different stages in study group also had obvious difference, statistical results of patients with higher stages were all worse than those of patients with lower stages, but the above statistical results among hepatic carcinoma patients with different types had no obvious difference, and the above detection indexes all had close relations with hepatic carcinoma by Logistic Analysis. Conclusion:The application value of CT perfusion imaging in patients with hepatic carcinoma was high, and it had active reaction value for the lesion blood flow of patients with hepatic carcinoma, and it also had high clinical value for the stages of disease.

  1. Dynamic CT myocardial perfusion imaging: detection of ischemia in a porcine model with FFR verification

    Science.gov (United States)

    Fahmi, Rachid; Eck, Brendan L.; Vembar, Mani; Bezerra, Hiram G.; Wilson, David L.

    2014-03-01

    Dynamic cardiac CT perfusion (CTP) is a high resolution, non-invasive technique for assessing myocardial blood ow (MBF), which in concert with coronary CT angiography enable CT to provide a unique, comprehensive, fast analysis of both coronary anatomy and functional ow. We assessed perfusion in a porcine model with and without coronary occlusion. To induce occlusion, each animal underwent left anterior descending (LAD) stent implantation and angioplasty balloon insertion. Normal ow condition was obtained with balloon completely de ated. Partial occlusion was induced by balloon in ation against the stent with FFR used to assess the extent of occlusion. Prospective ECG-triggered partial scan images were acquired at end systole (45% R-R) using a multi-detector CT (MDCT) scanner. Images were reconstructed using FBP and a hybrid iterative reconstruction (iDose4, Philips Healthcare). Processing included: beam hardening (BH) correction, registration of image volumes using 3D cubic B-spline normalized mutual-information, and spatio-temporal bilateral ltering to reduce partial scan artifacts and noise variation. Absolute blood ow was calculated with a deconvolutionbased approach using singular value decomposition (SVD). Arterial input function was estimated from the left ventricle (LV) cavity. Regions of interest (ROIs) were identi ed in healthy and ischemic myocardium and compared in normal and occluded conditions. Under-perfusion was detected in the correct LAD territory and ow reduction agreed well with FFR measurements. Flow was reduced, on average, in LAD territories by 54%.

  2. Decreases in molecular diffusion, perfusion fraction and perfusion-related diffusion in fibrotic livers: a prospective clinical intravoxel incoherent motion MR imaging study.

    Directory of Open Access Journals (Sweden)

    Pu-Xuan Lu

    Full Text Available PURPOSE: This study was aimed to determine whether pure molecular-based diffusion coefficient (D and perfusion-related diffusion parameters (perfusion fraction f, perfusion-related diffusion coefficient D* differ in healthy livers and fibrotic livers through intra-voxel incoherent motion (IVIM MR imaging. MATERIAL AND METHODS: 17 healthy volunteers and 34 patients with histopathologically confirmed liver fibrosis patients (stage 1 = 14, stage 2 = 8, stage 3 & 4 = 12, METAVIR grading were included. Liver MR imaging was performed at 1.5-T. IVIM diffusion weighted imaging sequence was based on standard single-shot DW spin echo-planar imaging, with ten b values of 10, 20, 40, 60, 80, 100, 150, 200, 400, 800 sec/mm2 respectively. Pixel-wise realization and regions-of-interest based quantification of IVIM parameters were performed. RESULTS: D, f, and D* in healthy volunteer livers and patient livers were 1.096±0.155 vs 0.917±0.152 (10(-3 mm2/s, p = 0.0015, 0.164±0.021 vs 0.123±0.029 (p<0.0001, and 13.085±2.943 vs 9.423±1.737 (10(-3 mm2/s, p<0.0001 respectively, all significantly lower in fibrotic livers. As the fibrosis severity progressed, D, f, and D* values decreased, with a trend significant for f and D*. CONCLUSION: Fibrotic liver is associated with lower pure molecular diffusion, lower perfusion volume fraction, and lower perfusion-related diffusion. The decrease of f and D* in the liver is significantly associated liver fibrosis severity.

  3. Metrology Standards for Quantitative Imaging Biomarkers.

    Science.gov (United States)

    Sullivan, Daniel C; Obuchowski, Nancy A; Kessler, Larry G; Raunig, David L; Gatsonis, Constantine; Huang, Erich P; Kondratovich, Marina; McShane, Lisa M; Reeves, Anthony P; Barboriak, Daniel P; Guimaraes, Alexander R; Wahl, Richard L

    2015-12-01

    Although investigators in the imaging community have been active in developing and evaluating quantitative imaging biomarkers (QIBs), the development and implementation of QIBs have been hampered by the inconsistent or incorrect use of terminology or methods for technical performance and statistical concepts. Technical performance is an assessment of how a test performs in reference objects or subjects under controlled conditions. In this article, some of the relevant statistical concepts are reviewed, methods that can be used for evaluating and comparing QIBs are described, and some of the technical performance issues related to imaging biomarkers are discussed. More consistent and correct use of terminology and study design principles will improve clinical research, advance regulatory science, and foster better care for patients who undergo imaging studies.

  4. Protection of lung function by introducing single photon emission computed tomography lung perfusion image into radiotherapy plan of lung cancer

    Institute of Scientific and Technical Information of China (English)

    YIN Yong; CHEN Jin-hu; LI Bao-sheng; LIU Tong-hai; LU jie; BAI Tong; DONG Xiao-ling; YU Jin-ming

    2009-01-01

    Background The lung functional status could be displayed on lung perfusion images. With the images, the radiotherapy plans of lung cancer could be guided to more optimized. This study aimed to assess quantitatively the impact of incorporating functional lung imaging into 3-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT) planning for non-small cell lung cancer (NSCLC).Methods Ten patients with NSCLC who had undergone radiotherapy were included in this study. Before radiotherapy,each patient underwent CT simulation and lung perfusion imaging with single photon emission computed tomography (SPECT). The SPECT images were registered with simulation planning CT and used to contour functional lung (lung-F) and non-functional lung (lung-NF). Two 3DCRT plans and two IMRT plans were designed and compared in each patient:two anatomic plans using simulation CT alone and two functional plans using SPECT-CT in addition to the simulation CT.Dosimetric parameters of the four types of plans were compared in terms of tumor coverage and avoidance of normal tissues. Total radiation dose was set at 66 Gy (2 Gy×33 fractions).Results In incorporating perfusion information in 3DCRT and IMRT planning, the reductions on average in the mean doses to the functional lung in the functional plan were 168 cGy and 89 cGy, respectively, compared with those in the anatomic plans. The median reductions in the percentage of volume irradiated with >5 Gy, >10 Gy, >20 Gy, >30 Gy and >40 Gy for functional lung in the functional plans were 6.50%, 10.21%, 14.02%, 22.30% and 23.46% in 3DCRT planning,respectively, and 3.05%, 15.52%, 14.16%, 4.87%, and 3.33% in IMRT planning, respectively. No greater degree of sparing of the functional lung was achieved in functional IMRT than in 3DCRT.Conclusion Function-guided 3DCRT and IMRT plannings both appear to be effective in preserving functional lung in NSCLC patients.

  5. Quantitative image analysis of celiac disease.

    Science.gov (United States)

    Ciaccio, Edward J; Bhagat, Govind; Lewis, Suzanne K; Green, Peter H

    2015-03-07

    We outline the use of quantitative techniques that are currently used for analysis of celiac disease. Image processing techniques can be useful to statistically analyze the pixular data of endoscopic images that is acquired with standard or videocapsule endoscopy. It is shown how current techniques have evolved to become more useful for gastroenterologists who seek to understand celiac disease and to screen for it in suspected patients. New directions for focus in the development of methodology for diagnosis and treatment of this disease are suggested. It is evident that there are yet broad areas where there is potential to expand the use of quantitative techniques for improved analysis in suspected or known celiac disease patients.

  6. Quantitative image analysis of celiac disease

    Science.gov (United States)

    Ciaccio, Edward J; Bhagat, Govind; Lewis, Suzanne K; Green, Peter H

    2015-01-01

    We outline the use of quantitative techniques that are currently used for analysis of celiac disease. Image processing techniques can be useful to statistically analyze the pixular data of endoscopic images that is acquired with standard or videocapsule endoscopy. It is shown how current techniques have evolved to become more useful for gastroenterologists who seek to understand celiac disease and to screen for it in suspected patients. New directions for focus in the development of methodology for diagnosis and treatment of this disease are suggested. It is evident that there are yet broad areas where there is potential to expand the use of quantitative techniques for improved analysis in suspected or known celiac disease patients. PMID:25759524

  7. Evaluating image denoising methods in myocardial perfusion single photon emission computed tomography (SPECT) imaging

    Science.gov (United States)

    Skiadopoulos, S.; Karatrantou, A.; Korfiatis, P.; Costaridou, L.; Vassilakos, P.; Apostolopoulos, D.; Panayiotakis, G.

    2009-10-01

    The statistical nature of single photon emission computed tomography (SPECT) imaging, due to the Poisson noise effect, results in the degradation of image quality, especially in the case of lesions of low signal-to-noise ratio (SNR). A variety of well-established single-scale denoising methods applied on projection raw images have been incorporated in SPECT imaging applications, while multi-scale denoising methods with promising performance have been proposed. In this paper, a comparative evaluation study is performed between a multi-scale platelet denoising method and the well-established Butterworth filter applied as a pre- and post-processing step on images reconstructed without and/or with attenuation correction. Quantitative evaluation was carried out employing (i) a cardiac phantom containing two different size cold defects, utilized in two experiments conducted to simulate conditions without and with photon attenuation from myocardial surrounding tissue and (ii) a pilot-verified clinical dataset of 15 patients with ischemic defects. Image noise, defect contrast, SNR and defect contrast-to-noise ratio (CNR) metrics were computed for both phantom and patient defects. In addition, an observer preference study was carried out for the clinical dataset, based on rankings from two nuclear medicine clinicians. Without photon attenuation conditions, denoising by platelet and Butterworth post-processing methods outperformed Butterworth pre-processing for large size defects, while for small size defects, as well as with photon attenuation conditions, all methods have demonstrated similar denoising performance. Under both attenuation conditions, the platelet method showed improved performance with respect to defect contrast, SNR and defect CNR in the case of images reconstructed without attenuation correction, however not statistically significant (p > 0.05). Quantitative as well as preference results obtained from clinical data showed similar performance of the

  8. Correlation of MR Perfusion-weighted Imaging of Prostatic Cancer with Tumor Angiogenesis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-bin; SHEN Jun-kang; XU Jian-ming; LI Xiao-bing

    2008-01-01

    Objective:MR perfusion-weighted imaging(PWI)has been widely applied in the research of cerebral tumor,benign and malignant musculoskeletal neoplasms and so on.The aim of this study is to explore the application of MR perfusion-weighted imaging in prostatic cancer(Pca),and evaluate the correlation of PWI features with vascular endothelial growth factor (VEGF)and microvessel density(MVD).Methods:Twenty-eight consecutive patients who were diagnosed clinically as prostatic cancer and thirty healthy volunteers were examined by PWI.MVD and VEGF were stained with immunohistochemical methods.Some parameters of PWI,including the steepest slope of signal intensity-time curve(SSmax)and the change in relaxation rate(△R2*peak)at lesions,were analyzed.Correlation analysis was used to determine the relationship between the results of PWI and that of immunohistochemistry.Results:(1)In the healthy volunteers.the steepest slope of signal intensity-time curve(SSmax)and △R2*peak of perfusion curve were;0.430±0.011,2.01±0.7 respectively;however,in the prostatic caucer,they were 57.8±5.0,3.0±0.6 respectively;with significant difference(t=4.11,3.28,P<0.01).(2)The VEGF and MVD expression of twenty-eight Pca patients were significantly higher.Conclusion:On MR perfusion.weighted imaging,SSmax and △R2*peak Can reflect MVD and VEGF expression levels in prostatic cancer.suggesting information on tumor angiogenesis.Thus they are beneficial to the diagnosis and treatment of prostatic cancer.

  9. Interictal diffusion and perfusion magnetic resonance imaging features of cats with familial spontaneous epilepsy.

    Science.gov (United States)

    Mizoguchi, Shunta; Hasegawa, Daisuke; Hamamoto, Yuji; Yu, Yoshihiko; Kuwabara, Takayuki; Fujiwara-Igarashi, Aki; Fujita, Michio

    2017-03-01

    OBJECTIVE To evaluate the usefulness of diffusion and perfusion MRI of the cerebrum in cats with familial spontaneous epilepsy (FSECs) and identify microstructural and functional deficit zones in affected cats. ANIMALS 19 FSECs and 12 healthy cats. PROCEDURES Diffusion-weighted, diffusion tensor, and perfusion-weighted MRI of the cerebrum were performed during interictal periods in FSECs. Imaging findings were compared between FSECs and control cats. Diffusion (apparent diffusion coefficient and fractional anisotropy) and perfusion (relative cerebral blood volume [rCBV], relative cerebral blood flow [rCBF], and mean transit time) variables were measured bilaterally in the hippocampus, amygdala, thalamus, parietal cortex gray matter, and subcortical white matter. Asymmetry of these variables in each region was also evaluated and compared between FSECs and control cats. RESULTS The apparent diffusion coefficient of the total amygdala of FSECs was significantly higher, compared with that of control cats. The fractional anisotropy of the right side and total hippocampus of FSECs was significantly lower, compared with that of control cats. The left and right sides and total hippocampal rCBV and rCBF were significantly lower in FSECs than in control cats. The rCBV and rCBF of the parietal cortex gray matter in FSECs were significantly lower than in control cats. CONCLUSIONS AND CLINICAL RELEVANCE In FSECs, diffusion and perfusion MRI detected microstructural changes and hypoperfusion (lowered function) in the cerebrum during interictal periods from that of healthy cats. These findings indicated that diffusion and perfusion MRI may be useful for noninvasive evaluation of epileptogenic foci in cats.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pannetier, N.

    2010-12-15

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

  11. 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

  12. ECG-gated HYPR reconstruction for undersampled CT myocardial perfusion imaging

    Science.gov (United States)

    Speidel, Michael A.; Van Lysel, Michael S.; Reeder, Scott B.; Supanich, Mark; Nett, Brian E.; Zambelli, Joseph; Chang, Su Min; Hsieh, Jiang; Chen, Guang-Hong; Mistretta, Charles A.

    2007-03-01

    In this study we develop a novel ECG-gated method of HYPR (HighlY constrained backPRojection) CT reconstruction for low-dose myocardial perfusion imaging and present its first application in a porcine model. HYPR is a method of reconstructing time-resolved images from view-undersampled projection data. Scanning and reconstruction techniques were explored using x-ray projections from a 50 sec contrast-enhanced axial scan of a 47 kg swine on a 64-slice MDCT system. Scans were generated with view undersampling factors from 2 to 10. A HYPR reconstruction algorithm was developed in which a fully-sampled composite image is generated from views collected from multiple cardiac cycles within a diastolic window. A time frame image for a heartbeat was produced by modifying the composite with projections from the cycle of interest. Heart rate variations were handled by automatically selecting cardiac window size and number of cycles per composite within defined limits. Cardiac window size averaged 35% of the R-R interval for 2x undersampling and increased to 64% R-R using 10x undersampling. The selected window size and cycles per composite was sensitive to synchrony between heart rate, gantry rate, and the view undersampling pattern. Temporal dynamics and perfusion metrics measured in conventional short-scan (FBP) images were well-reproduced in the undersampled HYPR time series. Mean transit times determined from HYPR myocardial time-density curves agreed to within 8% with the FBP results. The results indicate potential for an order of magnitude reduction in dose requirement per image in cardiac perfusion CT via undersampled scanning and ECG-gated HYPR reconstruction.

  13. Multislice computed tomography perfusion imaging for visualization of acute pulmonary embolism: animal experience

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, Joachim Ernst; Spuentrup, Elmar; Mahnken, Andreas H.; Guenther, Rolf W. [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Klotz, Ernst; Ditt, Hendrik [Computed Tomography, Siemens Medical Solutions, Forchheim (Germany)

    2005-07-01

    The purpose of our animal study was to evaluate a new computed tomography (CT) subtraction technique for visualization of perfusion defects within the lung parenchyma in subsegmental pulmonary embolism (PE). Seven healthy pigs were entered into a prospective trial. Acute PE was artificially induced by fresh clot material prior to the CT scans. Within a single breath-hold, whole thorax CT scans were performed with a 16-slice multidetector-row CT scanner (SOMATOM Sensation 16; Siemens, Forchheim, Germany) before and after intravenous application of 80 ml of contrast medium with a flow rate of 4 ml/s, followed by a saline chaser. The scan parameters were 120 kV and 100 mAs{sub eff}, using a thin collimation of 16 x 0.75 mm and a table speed/rotation of 15-18 mm (pitch, 1.25-1.5; rotation time, 0.5 s). Axial source images were reconstructed with an effective slice thickness of 1 mm (overlap, 30%). A new automatic subtraction technique was used. After 3D segmentation of the lungs in the plain and contrast-enhanced series, threshold-based extraction of major airways and vascular structures in the contrast images was performed. This segmentation was repeated in the plain CT images segmenting the same number of vessels and airways as in the contrast images. Both scans were registered onto each other using nonrigid registration. After registration both image sets were filtered in a nonlinear fashion excluding segmented airways and vessels. After subtracting the plain CT data from the contrast data the resulting enhancement images were color-encoded and overlaid onto the contrast-enhanced CT angiography (CTA) images. This color-encoded combined display of parenchymal enhancement of the lungs was evaluated interactively on a workstation (Leonardo, Siemens) in axial, coronal and sagittal plane orientations. Axial contrast-enhanced CTA images were rated first, followed by an analysis of the combination images. Finally, CTA images were reread focusing on areas with perfusion

  14. 3D ECG- and respiratory-gated non-contrast-enhanced (CE) perfusion MRI for postoperative lung function prediction in non-small-cell lung cancer patients: A comparison with thin-section quantitative computed tomography, dynamic CE-perfusion MRI, and perfusion scan.

    Science.gov (United States)

    Ohno, Yoshiharu; Seki, Shinichiro; Koyama, Hisanobu; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Takenaka, Daisuke; Kassai, Yoshimori; Yui, Masao; Sugimura, Kazuro

    2015-08-01

    To compare predictive capabilities of non-contrast-enhanced (CE)- and dynamic CE-perfusion MRIs, thin-section multidetector computed tomography (CT) (MDCT), and perfusion scan for postoperative lung function in non-small cell lung cancer (NSCLC) patients. Sixty consecutive pathologically diagnosed NSCLC patients were included and prospectively underwent thin-section MDCT, non-CE-, and dynamic CE-perfusion MRIs and perfusion scan, and had their pre- and postoperative forced expiratory volume in one second (FEV1 ) measured. Postoperative percent FEV1 (po%FEV1 ) was then predicted from the fractional lung volume determined on semiquantitatively assessed non-CE- and dynamic CE-perfusion MRIs, from the functional lung volumes determined on quantitative CT, from the number of segments observed on qualitative CT, and from uptakes detected on perfusion scans within total and resected lungs. Predicted po%FEV1 s were then correlated with actual po%FEV1 s, which were %FEV1 s measured postoperatively. The limits of agreement were also determined. All predicted po%FEV1 s showed significant correlation (0.73 ≤ r ≤ 0.93, P CE-perfusion MRI: 0.3 ± 10.0%, dynamic CE-perfusion MRI: 1.0 ± 10.8%, perfusion scan: 2.2 ± 14.1%, quantitative CT: 1.2 ± 9.0%, qualitative CT: 1.5 ± 10.2%). Non-CE-perfusion MRI may be able to predict postoperative lung function more accurately than qualitatively assessed MDCT and perfusion scan. © 2014 Wiley Periodicals, Inc.

  15. Influence of pulmonary regurgitation inequality on differential perfusion of the lungs in tetralogy of Fallot after repair: a phase-contrast magnetic resonance imaging and perfusion scintigraphy study.

    Science.gov (United States)

    Wu, Ming-Ting; Huang, Yi-Luan; Hsieh, Kai-Sheng; Huang, Ju-Tung; Peng, Nan-Jing; Pan, Jun-Yen; Huang, Jer-Shyung; Yang, Tsung-Lung

    2007-05-08

    The purpose of this study was to evaluate the influence of pulmonary regurgitation inequality on differential perfusion of the lungs in tetralogy of Fallot (TOF) after repair. Asymmetry of lung perfusion is one of the best predictors of outcome in TOF after repair. A recent phase-contrast magnetic resonance imaging (PC-MRI) study found prominent regurgitation inequality between the bilateral pulmonary arteries in TOF after repair. Forty-three TOF post-repair patients (median age = 51 months, 31 men) received PC-MRI and 99mTc-labeled macroaggregates of albumin perfusion scintigraphy (PS) in the same day. We took PC-MRI measurements of forward flow volume (FFV), backward flow volume (BFV), and net flow volume (NFV) (NFV = FFV - BFV) and regurgitation fraction (RF) (RF = BFV/FFV) at the left and right pulmonary arteries (LPA and RPA). The differential perfusion of the left lung (L%) (L% = left lung/left + right lung) as calculated by NFV ratio, by FFV ratio of PC-MRI, and by PS were compared. The discrepancy between L% by NFV versus L% by PS was affected by the severity of RF of LPA (r = -0.51, p = 0.001); agreement between L% by NFV versus L% by PS was good (intraclass correlation coefficient [Ri] = 0.87) if RF of LPA or =0.4 (n = 20). In contrast, agreement between L% by FFV versus L% by PS was high and unaffected by RF of LPA (Ri = 0.94, 0.92, respectively). While integrating PC-MRI of pulmonary artery as a comprehensive MRI evaluation of TOF after repair, conventional NFV ratio method tended to underestimate the left lung perfusion and may lead to unnecessary intervention. The FFV ratio method should be used for precise assessment of differential lung perfusion.

  16. Imaging abnormalities in sporadic hemiplegic migraine on conventional MRI, diffusion and perfusion MRI and MRS.

    Science.gov (United States)

    Jacob, A; Mahavish, K; Bowden, A; Smith, E T S; Enevoldson, P; White, R P

    2006-08-01

    Prolonged hemiparetic migraine aura can cause diagnostic confusion and be mistaken for ischaemic stroke occurring during the course of a migraine--'migrainous infarction'. We report a case of prolonged hemiparesis occurring during the course of a migraine attack. Though initially confused with migrainous infarction, we suggest with sequential magnetic resonance imaging, magnetic resonance angiography, diffusion, perfusion images and magnetic resonance spectroscopy that the hemiplegia was not of vascular origin and that the patient had sporadic hemiplegic migraine. We hypothesize that the mechanisms of sporadic hemiplegic migraine probably lie at a cellular level, similiar to familial hemiplegic migraine.

  17. SU-C-201-04: Quantification of Perfusion Heterogeneity Based On Texture Analysis for Fully Automatic Detection of Ischemic Deficits From Myocardial Perfusion Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Y [National Cheng Kung University, Tainan, Taiwan (China); Huang, H [Chang Gung University, Taoyuan, Taiwan (China); Su, T [Chang Gung Memorial Hospital, Taoyuan, Taiwan (China)

    2015-06-15

    Purpose: Texture-based quantification of image heterogeneity has been a popular topic for imaging studies in recent years. As previous studies mainly focus on oncological applications, we report our recent efforts of applying such techniques on cardiac perfusion imaging. A fully automated procedure has been developed to perform texture analysis for measuring the image heterogeneity. Clinical data were used to evaluate the preliminary performance of such methods. Methods: Myocardial perfusion images of Thallium-201 scans were collected from 293 patients with suspected coronary artery disease. Each subject underwent a Tl-201 scan and a percutaneous coronary intervention (PCI) within three months. The PCI Result was used as the gold standard of coronary ischemia of more than 70% stenosis. Each Tl-201 scan was spatially normalized to an image template for fully automatic segmentation of the LV. The segmented voxel intensities were then carried into the texture analysis with our open-source software Chang Gung Image Texture Analysis toolbox (CGITA). To evaluate the clinical performance of the image heterogeneity for detecting the coronary stenosis, receiver operating characteristic (ROC) analysis was used to compute the overall accuracy, sensitivity and specificity as well as the area under curve (AUC). Those indices were compared to those obtained from the commercially available semi-automatic software QPS. Results: With the fully automatic procedure to quantify heterogeneity from Tl-201 scans, we were able to achieve a good discrimination with good accuracy (74%), sensitivity (73%), specificity (77%) and AUC of 0.82. Such performance is similar to those obtained from the semi-automatic QPS software that gives a sensitivity of 71% and specificity of 77%. Conclusion: Based on fully automatic procedures of data processing, our preliminary data indicate that the image heterogeneity of myocardial perfusion imaging can provide useful information for automatic determination

  18. Use of neural networks to improve quality control of interpretations in myocardial perfusion imaging

    DEFF Research Database (Denmark)

    Tagil, K.; Marving, J.; Lomsky, M.

    2008-01-01

    ). METHODS: Reversible perfusion defects (ischaemia) in each of five myocardial regions, as interpreted by one experienced nuclear medicine physician during his daily routine of clinical reporting, were assessed by artificial neural networks in 316 consecutive patients undergoing stress/rest 99m...... cases. Forty-six of the 53 cases (87%) came from the group selected by the neural networks, and only seven (13%) were control cases (P medicine expert and artificial networks were related to small and mild......BACKGROUND: The aim of this study was to explore the feasibility of using a technique based on artificial neural networks for quality assurance of image reporting. The networks were used to identify potentially suboptimal or erroneous interpretations of myocardial perfusion scintigrams (MPS...

  19. Quantitative Analysis in Nuclear Medicine Imaging

    CERN Document Server

    2006-01-01

    This book provides a review of image analysis techniques as they are applied in the field of diagnostic and therapeutic nuclear medicine. Driven in part by the remarkable increase in computing power and its ready and inexpensive availability, this is a relatively new yet rapidly expanding field. Likewise, although the use of radionuclides for diagnosis and therapy has origins dating back almost to the discovery of natural radioactivity itself, radionuclide therapy and, in particular, targeted radionuclide therapy has only recently emerged as a promising approach for therapy of cancer and, to a lesser extent, other diseases. As effort has, therefore, been made to place the reviews provided in this book in a broader context. The effort to do this is reflected by the inclusion of introductory chapters that address basic principles of nuclear medicine imaging, followed by overview of issues that are closely related to quantitative nuclear imaging and its potential role in diagnostic and therapeutic applications. ...

  20. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K [University of Washington, Department of Bioengineering, Seattle, Washington 98195 (United States)

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  1. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Science.gov (United States)

    Ogami, M.; Kulkarni, R.; Wang, H.; Reif, R.; Wang, R. K.

    2014-08-01

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing.

  2. Application progress of CT perfusion imaging technique in hepatitis and cirrhosis%CT 灌注成像技术在肝炎、肝硬化中的应用进展

    Institute of Scientific and Technical Information of China (English)

    马振波; 谢元忠

    2015-01-01

    The liver CT perfusion imaging technique can reflect the hemodynamic status and function of organs and tissues ,which is classified as a noninvasive functional imaging .CT perfusion imaging technique can not only reflect the hemodynamic changes of liver ,but also be used for quantitative analysis .The basic principle and methods of examination and analysis of the CT perfusion imaging technique , normal liver CT perfusion imaging ,the present research situation and development prospect of the CT perfusion of hepatitis and cirrhosis are reviewed in this paper .%肝脏的CT灌注成像技术能够反映器官及组织的血流动力学状态和功能情况,属于无创的功能性成像。 CT灌注成像技术不仅可以反映肝脏血流动力学变化,而且可以进行定量分析。本文就CT灌注成像基本原理及检查、分析方法,正常肝脏CT灌注成像,肝炎、肝硬化CT灌注的研究现状及发展前景进行综述。

  3. A methodology for generating normal and pathological brain perfusion SPECT images for evaluation of MRI/SPECT fusion methods: application in epilepsy

    Science.gov (United States)

    Grova, C.; Jannin, P.; Biraben, A.; Buvat, I.; Benali, H.; Bernard, A. M.; Scarabin, J. M.; Gibaud, B.

    2003-12-01

    Quantitative evaluation of brain MRI/SPECT fusion methods for normal and in particular pathological datasets is difficult, due to the frequent lack of relevant ground truth. We propose a methodology to generate MRI and SPECT datasets dedicated to the evaluation of MRI/SPECT fusion methods and illustrate the method when dealing with ictal SPECT. The method consists in generating normal or pathological SPECT data perfectly aligned with a high-resolution 3D T1-weighted MRI using realistic Monte Carlo simulations that closely reproduce the response of a SPECT imaging system. Anatomical input data for the SPECT simulations are obtained from this 3D T1-weighted MRI, while functional input data result from an inter-individual analysis of anatomically standardized SPECT data. The method makes it possible to control the 'brain perfusion' function by proposing a theoretical model of brain perfusion from measurements performed on real SPECT images. Our method provides an absolute gold standard for assessing MRI/SPECT registration method accuracy since, by construction, the SPECT data are perfectly registered with the MRI data. The proposed methodology has been applied to create a theoretical model of normal brain perfusion and ictal brain perfusion characteristic of mesial temporal lobe epilepsy. To approach realistic and unbiased perfusion models, real SPECT data were corrected for uniform attenuation, scatter and partial volume effect. An anatomic standardization was used to account for anatomic variability between subjects. Realistic simulations of normal and ictal SPECT deduced from these perfusion models are presented. The comparison of real and simulated SPECT images showed relative differences in regional activity concentration of less than 20% in most anatomical structures, for both normal and ictal data, suggesting realistic models of perfusion distributions for evaluation purposes. Inter-hemispheric asymmetry coefficients measured on simulated data were found within

  4. Liver perfusion CT during hepatic arteriography for the hepatocellular carcinoma: Dose reduction and quantitative evaluation for normal- and ultralow-dose protocol

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Shingo [Department of Radiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50, Minami-Koshigaya, Koshigaya-shi, Saitama 343-8555 (Japan); Katada, Yoshiaki, E-mail: yoshiaki@dokkyomed.ac.jp [Department of Radiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50, Minami-Koshigaya, Koshigaya-shi, Saitama 343-8555 (Japan); Gohkyu, Masaki; Nakajima, Masahiro; Kawabata, Hideyuki; Nozaki, Miwako [Department of Radiology, Dokkyo Medical University Koshigaya Hospital, 2-1-50, Minami-Koshigaya, Koshigaya-shi, Saitama 343-8555 (Japan)

    2012-12-15

    Objectives: The purpose of this study was to investigate whether substantial reduction of the computed tomography (CT) dose is possible in liver CT perfusion imaging by comparing the results of ultralow-dose CT perfusion imaging with those of conventional CT perfusion imaging the same patients and under the same conditions. Materials and methods: The study was composed following two parts: computer simulation and patients study. In computer simulation, noise was added to the images so that the standard deviation (SD) of the CT values in the liver parenchyma became various values using ImageJ. Time density curves (TDCs) were created from the simulated data, and the influence of difference in the SDs on the shapes of the TDCs was investigated. In the patient study, CT perfusion during intra-arterial injection was performed in 30 consecutive patients undergoing transcatheter arterial chemoembolization. CT perfusion images were acquired twice, at 100 mA (CTDI{sub vol}, 300 mGy) for normal and at 20 mA (CTDI{sub vol}, 60 mGy) for the ultralow radiation doses, under the same conditions. Results: No change was observed in the shape of the TDCs and peak values in the analysis of simulation images. A very good correlation was observed between the normal- and ultralow-dose CT images for all analyzed values (R{sup 2} = 0.9885 for blood flow, 0.9269 for blood volume, and 0.8424 for mean transit time). Conclusions: Our results demonstrated that there was no significant difference in the analysis results of perfusion CT between ultralow-dose CT performed using 20% of the conventional dose and normal-dose CT perfusion.

  5. Reference Range of Functional Data of Gated Myocardial Perfusion SPECT by Quantitative Gated SPECT of Cedars-Sinai and 4D-MSPECT of Michigan University

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Kim, Moo Hyun; Kim, Young Dae [College of Medicine, Univ. of Donga, Pusan (Korea, Republic of)

    2003-07-01

    Various programs have been developed for gating of myocardial perfusion SPECT. Among the those program, the most popular program is the Quantitative Gated SPECT (QGS)? developed by Cedars-Sinai hospital and most recently released program is 4D-MSPECT? developed by university of Michigan. It is important to know the reference range of the functional data of gated myocardial perfusion SPECT because it is necessary to determine abnormality of individual patient and echocardiographic data is different from those of gated SPECT. Tc-99m MIBI gated myocardial perfusion SPECT image was reconstructed by dual head gamma camera (Siemens, BCAM, esoft) as routine procedure and analyzed using QGS? and 4D-MSPECT? program. All patients (M: F=9: 18, Age 69{+-}9 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded: previous angina or MI history, ECG change with Q wave or ST-T change, diabetes melitius, hypercholesterolemia, typical chest pain, hypertension and cardiomyopathy. Pre-test likelihood of all patients was low. (1) In stress gated SPECT by QGS?, EDV was 73{+-}25 ml, ESV 25{+-}14 ml, EF 67{+-}11 % and area of first frame of gating 106.4{+-}21cm{sup 2}. In rest gated SPECT, EDV was 76{+-}26 ml, ESV 27{+-}15 ml, EF 66{+-}12 and area of first frame of gating 108{+-}20cm{sup 2}. (2) In stress gated SPECT by 4D-MSPECT?, EDV was 76{+-}28 ml, ESV 23{+-}16 ml, EF 72{+-}11 %, mass 115{+-}24 g and ungated volume 42{+-}15 ml. In rest gated SPECT, EDV was 75{+-}27 ml, ESV 23{+-}12 ml, EF 71{+-}9%, mass 113{+-}25g and ungate dvolume 42{+-}15 ml, (3) s-EDV, s-EF, r-ESV and r-EF were significantly different between QGS? and 4D-MSPECT? (each p=0.016, p<0.001. p=0.003 and p=0.001). We determined the normal reference range of functional parameters by QGS? and 4D-MSPECT? program to diagnose individually the abnormality of patients. And the reference ranges have to adopted to be patients by each specific gating program.

  6. Perfusion Reduction at Transcatheter Intraarterial Perfusion MR Imaging: A Promising Intraprocedural Biomarker to Predict Transplant-Free Survival during Chemoembolization of Hepatocellular Carcinoma

    Science.gov (United States)

    Wang, Dingxin; Gaba, Ron C.; Jin, Brian; Lewandowski, Robert J.; Riaz, Ahsun; Memon, Khairuddin; Ryu, Robert K.; Sato, Kent T.; Kulik, Laura M.; Mulcahy, Mary F.; Larson, Andrew C.; Salem, Riad

    2014-01-01

    Purpose To investigate the predictive value of transcatheter intraarterial perfusion (TRIP) magnetic resonance (MR) imaging–measured tumor perfusion changes during transarterial chemoembolization on transplant-free survival (TFS) in patients with unresectable hepatocellular carcinoma (HCC). Materials and Methods This HIPAA-compliant prospective study was approved by the institutional review board. Written informed consent was obtained from all patients. Fifty-one consecutive adult patients with surgically unresectable single or multifocal measurable HCC and adequate laboratory parameters who underwent chemoembolization in a combined MR imaging–interventional radiology suite between February 2006 and June 2010 were studied. Tumor perfusion changes during chemoembolization were measured by using TRIP MR imaging with area under the time–signal intensity curve calculation. The end point of the study was TFS. The authors assessed the correlation between the percentage perfusion reduction in the tumor during chemoembolization and TFS by using univariate and multivariate analyses. Results Fifty patients (mean age, 61 years; 39 men aged 42–87 years [mean age, 61 years] and 11 women aged 49–83 years [mean age, 62 years]) were eligible for the analysis. Patients with 35%–85% intraprocedural tumor area under the time–signal intensity curve reduction (n = 32) showed significantly improved median TFS compared with patients with an area under the time–signal intensity curve reduction outside this range (n = 18) (16.6 months [95% confidence interval: 11.2, 22.0 months] vs 9.3 months [95% confidence interval: 6.6, 12.0 months], respectively; P = .046; hazard ratio: 0.46; 95% confidence interval: 0.21, 1.00). The cumulative TFS rates in the 35%–85% and less than 35% or more than 85% perfusion reduction groups at 1, 2, and 5 years after chemoembolization were 66.4%, 42.2%, and 28.2% versus 33.8%, 16.9%, and 0%, respectively. Conclusion The study shows evidence of

  7. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Coenen, Adriaan; Lubbers, Marisa M.; Dedic, Admir; Chelu, Raluca G.; Geuns, Robert-Jan M. van; Nieman, Koen [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus University Medical Center, Department of Cardiology, Rotterdam (Netherlands); Kurata, Akira; Kono, Atsushi; Dijkshoorn, Marcel L. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Rossi, Alexia [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Barts Health NHS Trust, NIHR Cardiovascular Biomedical Research Unit at Barts, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Department of Cardiology, London (United Kingdom)

    2017-06-15

    To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Subjects with suspected or known coronary artery disease were prospectively included and underwent a CT-MPI examination. From the CT-MPI time-point data absolute myocardial blood flow (MBF) values were temporally resolved using a hybrid deconvolution model. An absolute MBF value was measured in the suspected perfusion defect. TPR was defined as the ratio between the subendocardial and subepicardial MBF. TPR and MBF results were compared with invasive FFR using a threshold of 0.80. Forty-three patients and 94 territories were analysed. The area under the receiver operator curve was larger for MBF (0.78) compared with TPR (0.65, P = 0.026). No significant differences were found in diagnostic classification between MBF and TPR with a territory-based accuracy of 77 % (67-86 %) for MBF compared with 70 % (60-81 %) for TPR. Combined MBF and TPR classification did not improve the diagnostic classification. Dynamic CT-MPI-based transmural perfusion ratio predicts haemodynamically significant coronary artery disease. However, diagnostic performance of dynamic CT-MPI-derived TPR is inferior to quantified MBF and has limited incremental value. (orig.)

  8. A Method of Time-Intensity Curve Calculation for Vascular Perfusion of Uterine Fibroids Based on Subtraction Imaging with Motion Correction

    Science.gov (United States)

    Zhu, Xinjian; Wu, Ruoyu; Li, Tao; Zhao, Dawei; Shan, Xin; Wang, Puling; Peng, Song; Li, Faqi; Wu, Baoming

    2016-12-01

    The time-intensity curve (TIC) from contrast-enhanced ultrasound (CEUS) image sequence of uterine fibroids provides important parameter information for qualitative and quantitative evaluation of efficacy of treatment such as high-intensity focused ultrasound surgery. However, respiration and other physiological movements inevitably affect the process of CEUS imaging, and this reduces the accuracy of TIC calculation. In this study, a method of TIC calculation for vascular perfusion of uterine fibroids based on subtraction imaging with motion correction is proposed. First, the fibroid CEUS recording video was decoded into frame images based on the record frame rate. Next, the Brox optical flow algorithm was used to estimate the displacement field and correct the motion between two frames based on warp technique. Then, subtraction imaging was performed to extract the positional distribution of vascular perfusion (PDOVP). Finally, the average gray of all pixels in the PDOVP from each image was determined, and this was considered the TIC of CEUS image sequence. Both the correlation coefficient and mutual information of the results with proposed method were larger than those determined using the original method. PDOVP extraction results have been improved significantly after motion correction. The variance reduction rates were all positive, indicating that the fluctuations of TIC had become less pronounced, and the calculation accuracy has been improved after motion correction. This proposed method can effectively overcome the influence of motion mainly caused by respiration and allows precise calculation of TIC.

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

    Science.gov (United States)

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

    2015-03-01

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

  10. Improved diagnostic accuracy of lung perfusion imaging using Tc-99m MAA SPECT

    Energy Technology Data Exchange (ETDEWEB)

    O' Donnell, J.K.; Golish, J.A.; Go, R.T.; Risius, B.; Graor, R.A.; MacIntyre, W.J.; Feiglin, D.H.

    1984-01-01

    The addition of emission tomography (SPECT) to pulmonary perfusion imaging should improve diagnostic accuracy by detecting perfusion defects otherwise masked by superimposition of normal lung activity and by reducing problems with interpretation of defects that result from overlying soft tissue or pleural effusions. In order to examine the contribution of SPECT in the scintigraphic evaluation for pulmonary embolus (PE), the authors have obtained both planar and SPECT studies in 94 cases of suspected PE. All studies employed 3-4 mCi of Tc-99m MAA and standard six-view planar image acquisition. SPECT raw data of 64 images were then acquired over a 360 degree transaxial rotation with subsequent computer reconstruction. Xe-133 ventilation studies were performed when clinically indicated and tolerated by the patient. For 19 studies angiographic (AN) correlation was obtained within 24 hours. In 16/19 planar and SPECT both gave a high probability of PE but SPECT gave better segmental localization and showed better agreement with the number of defects seen at AN. In 3 indeterminate planar scans, 2 were low probability with SPECT and had negative AN. The third, a patient with Wegener's vasculitis, remained indeterminate with SPECT and had negative AN. Five patients with PE had repeat planar/SPECT/AN studies to evaluate response to treatment. SPECT correlated better with AN findings in each case. The authors conclude that SPECT perfusion imaging provides better anatomic accuracy for defects representing PE and is the non-invasive technique of choice for documenting response to therapy.

  11. Treatment assessment of radiotherapy using MR functional quantitative imaging

    Institute of Scientific and Technical Information of China (English)

    Zheng; Chang; Chunhao; Wang

    2015-01-01

    Recent developments in magnetic resonance(MR) functional quantitative imaging have made it a potentially powerful tool to assess treatment response in radiation therapy. With its abilities to capture functional information on underlying tissue characteristics, MR functional quantitative imaging can be valuable in assessing treatment response and as such to optimize therapeutic outcome. Various MR quantitative imaging techniques, including diffusion weighted imaging, diffusion tensor imaging, MR spectroscopy and dynamic contrastenhanced imaging, have been investigated and found useful for assessment of radiotherapy. However, various aspects including data reproducibility, interpretation of biomarkers, image quality and data analysis impose challenges on applications of MR functional quantitative imaging in radiotherapy assessment. All of these challenging issues shall be addressed to help us understand whether MR functional quantitative imaging is truly beneficial and contributes to future development of radiotherapy. It is evident that individualized therapy is the future direction of patient care. MR functional quantitative imaging might serves as an indispensable tool towards this promising direction.

  12. Quantitative phase imaging through scattering media

    Science.gov (United States)

    Kollárová, Vera; Colláková, Jana; Dostál, Zbynek; Slabý, Tomas; Veselý, Pavel; Chmelík, Radim

    2015-03-01

    Coherence-controlled holographic microscope (CCHM) is an off-axis holographic system. It enables observation of a sample and its quantitative phase imaging with coherent as well as with incoherent illumination. The spatial and temporal coherence can be modified and thus also the quality and type of the image information. The coherent illumination provides numerical refocusing in wide depth range similarly to a classic coherent-light digital holographic microscopy (HM). Incoherent-light HM is characterized by a high quality, coherence-noise-free imaging with up to twice higher resolution compared to coherent illumination. Owing to an independent, free of sample reference arm of the CCHM the low spatial light coherence induces coherence-gating effect. This makes possible to observe specimen also through scattering media. We have described theoretically and simulated numerically imaging of a two dimensional object through a scattering layer by CCHM using the linear systems theory. We have investigated both strongly and weakly scattering media characterized by different amount of ballistic and diffuse light. The influence of a scattering layer on the quality of a phase signal is discussed for both types of the scattering media. A strong dependence of the imaging process on the light coherence is demonstrated. The theoretical calculations and numerical simulations are supported by experimental data gained with model samples, as well as real biologic objects particularly then by time-lapse observations of live cells reactions to substances producing optically turbid emulsion.

  13. TU-EF-204-02: Hiigh Quality and Sub-MSv Cerebral CT Perfusion Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ke; Niu, Kai; Wu, Yijing; Chen, Guang-Hong [University of Wisconsin, Madison, WI (United States)

    2015-06-15

    Purpose: CT Perfusion (CTP) imaging is of great importance in acute ischemic stroke management due to its potential to detect hypoperfused yet salvageable tissue and distinguish it from definitely unsalvageable tissue. However, current CTP imaging suffers from poor image quality and high radiation dose (up to 5 mSv). The purpose of this work was to demonstrate that technical innovations such as Prior Image Constrained Compressed Sensing (PICCS) have the potential to address these challenges and achieve high quality and sub-mSv CTP imaging. Methods: (1) A spatial-temporal 4D cascaded system model was developed to indentify the bottlenecks in the current CTP technology; (2) A task-based framework was developed to optimize the CTP system parameters; (3) Guided by (1) and (2), PICCS was customized for the reconstruction of CTP source images. Digital anthropomorphic perfusion phantoms, animal studies, and preliminary human subject studies were used to validate and evaluate the potentials of using these innovations to advance the CTP technology. Results: The 4D cascaded model was validated in both phantom and canine stroke models. Based upon this cascaded model, it has been discovered that, as long as the spatial resolution and noise properties of the 4D source CT images are given, the 3D MTF and NPS of the final CTP maps can be analytically derived for a given set of processing methods and parameters. The cascaded model analysis also identified that the most critical technical factor in CTP is how to acquire and reconstruct high quality source images; it has very little to do with the denoising techniques often used after parametric perfusion calculations. This explained why PICCS resulted in a five-fold dose reduction or substantial improvement in image quality. Conclusion: Technical innovations generated promising results towards achieving high quality and sub-mSv CTP imaging for reliable and safe assessment of acute ischemic strokes. K. Li, K. Niu, Y. Wu: Nothing to

  14. Novel Cadmium Zinc Telluride Devices for Myocardial Perfusion Imaging-Technological Aspects and Clinical Applications.

    Science.gov (United States)

    Ben-Haim, Simona; Kennedy, John; Keidar, Zohar

    2016-07-01

    Myocardial perfusion imaging plays an important role in the assessment of patients with known or suspected coronary artery disease and is well established for diagnosis and for prognostic evaluation in these patients. The dedicated cardiac SPECT cameras with solid-state cadmium zinc telluride (CZT) detectors were first introduced a decade ago. A large body of evidence is building up, showing the superiority of the new technology compared with conventional gamma cameras. Not only the CZT detectors, but also new collimator geometries, the ability to perform focused imaging optimized for the heart and advances in data processing algorithms all contribute to the significantly improved sensitivity up to 8-10 times, as well as improved energy resolution and improved reconstructed spatial resolution compared with conventional technology. In this article, we provide an overview of the physical characteristics of the CZT cameras, as well as a review of the literature published so far, including validation studies in comparison with conventional myocardial perfusion imaging and with invasive coronary angiography, significant reduction in radiation dose, and new imaging protocols enabled by the new technology.

  15. The Use of Smart Phone Thermal Imaging for Assessment of Peripheral Perfusion in Vascular Patients.

    Science.gov (United States)

    Wallace, Gabriel A; Singh, Niten; Quiroga, Elina; Tran, Nam T

    2017-09-05

    Ankle brachial index (ABI) is a reliable method to evaluate extremity perfusion but can be prohibitive to obtain secondary to patient discomfort or extremity trauma. This study investigates smart phone based forward looking infrared imaging (FLIR) to assess peripheral perfusion using thermal ABI (tABI). ABI's were measured by a certified vascular laboratory. Thermographs of each extremity (hands/feet) were obtained and maximum surface temperature recorded. tABI was calculated by dividing the lower extremity (LE) temperature by the upper extremity (UE). ABI and tABI were compared using Pearson's correlation and Bland-Altman plot. Twenty three patients (45 limbs) had ABI's and thermographs recorded on the same day. Median ABI was 0.89 (range 0.33-1.46, IQR 0.4). Median LE temperature was 83.0°F (range 60.7-96.9°F, IQR 14.1). Median UE temperature was 91.2°F (range 81.9-94.6°F, IQR 3.4). Median tABI was 0.93 (range 0.33-1.4, IQR 0.2). Positive correlation was seen between ABI and tABI with Pearson analysis(r = 0.83, p Smart phone based FLIR can be utilized to determine peripheral perfusion in clinical settings where ABI is difficult to obtain. Copyright © 2017. Published by Elsevier Inc.

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

    Science.gov (United States)

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

    2016-01-01

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

  17. Investigation of the potential causes of partial scan artifacts in dynamic CT myocardial perfusion imaging

    Science.gov (United States)

    Tao, Yinghua; Speidel, Michael; Szczykutowicz, Timothy; Chen, Guang-Hong

    2014-03-01

    In recent years, there have been several findings regarding CT number variations (partial scan artifact or PSA) across time in dynamic myocardial perfusion studies with short scan gated reconstruction. These variations are correlated with the view angle range corresponding to the short scan acquisition for a given cardiac phase, which can vary from one cardiac cycle to another due to the asynchrony between heart rate and gantry rotation speed. In this study, we investigate several potential causes of PSA, including noise, beam hardening and scatter, using numerical simulations. In addition, we investigate partial scan artifact in a single source 64-slice diagnostic CT scanner in vivo data sets, and report its effect on perfusion analysis. Results indicated that among all three factors investigated, scatter can cause obvious partial scan artifact in dynamic myocardial perfusion imaging. Further, scatter is a low frequency phenomenon and is not heavily dependent on the changing contrasts, as both the frequency method and the virtual scan method are effective in reducing partial scan artifact. However, PSA does not necessarily lead to different blood volume maps compared to the full scan, because these maps are usually generated with a curve fitting procedure.

  18. Risk assessment by myocardial perfusion imaging for coronary revascularization, medical therapy, and noncardiac surgery.

    Science.gov (United States)

    Papaioannou, Georgios I; Heller, Gary V

    2003-01-01

    Stress myocardial perfusion imaging (MPI) has become an important tool in risk stratification of patients with known coronary artery disease. A normal myocardial perfusion scan has a high negative predictive value and is associated with low annual mortality rate ( 20% of the left ventricle), defects in more than 1 coronary vascular territory, transient or persistent left ventricular cavity dilation, and ejection fraction less than 45% have a high annual mortality rate (> 3%). Those patients should undergo coronary revascularization whenever feasible, as the cardiac event rate increases in proportion to the magnitude of the jeopardized myocardium. Stress MPI can be used to demonstrate ischemia in patients with symptoms early after coronary artery bypass surgery (/= 5 years) after coronary artery bypass surgery. With respect to patients who underwent percutaneous interventions, stress MPI can help detect in-stent restenosis early after the intervention (3-6 months) or assess the progression of native coronary disease afterward. Since preliminary data suggest that a reduction in the perfusion defect size may translate to a reduction of coronary events, stress MPI can help assess the efficacy of medical management of coronary disease. Finally, stress MPI is indicated for perioperative cardiac risk stratification for noncardiac surgery in patients with intermediate risk predictors (mild angina, prior myocardial infarction or heart failure symptoms, diabetes mellitus, renal insufficiency) and poor functional capacity or in those who undergo high-risk surgery with significant implications in further preoperative management.

  19. Improved first-pass spiral myocardial perfusion imaging with variable density trajectories.

    Science.gov (United States)

    Salerno, Michael; Sica, Christopher; Kramer, Christopher M; Meyer, Craig H

    2013-11-01

    To develop and evaluate variable-density spiral first-pass perfusion pulse sequences for improved efficiency and off-resonance performance and to demonstrate the utility of an apodizing density compensation function (DCF) to improve signal-to-noise ratio (SNR) and reduce dark-rim artifact caused by cardiac motion and Gibbs Ringing. Three variable density spiral trajectories were designed, simulated, and evaluated in 18 normal subjects, and in eight patients with cardiac pathology on a 1.5T scanner. By using a DCF, which intentionally apodizes the k-space data, the sidelobe amplitude of the theoretical point spread function (PSF) is reduced by 68%, with only a 13% increase in the full-width at half-maximum of the main-lobe when compared with the same data corrected with a conventional variable-density DCF, and has an 8% higher resolution than a uniform density spiral with the same number of interleaves and readout duration. Furthermore, this strategy results in a greater than 60% increase in measured SNR when compared with the same variable-density spiral data corrected with a conventional DCF (P density spiral pulse sequences using an apodized DCF produce high-quality first-pass perfusion images with minimal dark-rim and off-resonance artifacts, high SNR and contrast-to-noise ratio, and good delineation of resting perfusion abnormalities. Copyright © 2012 Wiley Periodicals, Inc.

  20. Selective microvascular muscle perfusion imaging in the shoulder with intravoxel incoherent motion (IVIM).

    Science.gov (United States)

    Nguyen, Audrey; Ledoux, Jean-Baptiste; Omoumi, Patrick; Becce, Fabio; Forget, Joachim; Federau, Christian

    2017-01-01

    The evaluation of local muscle recruitment during a specific movement can be done indirectly by measuring changes in local blood flow. Intravoxel incoherent motion perfusion imaging exploits some properties of the magnetic resonance to measure locally microvascular perfusion, and seems ideally suited for this task. We studied the selectivity of the increase in intravoxel incoherent motion blood flow related parameter fD* in the muscles of 24 shoulders after two physical exam maneuvers, Jobe and Lift-off test (test order reversed in half of the volunteers) each held 2min against resistance. After a lift-off, IVIM blood flow-related fD* was increased in the subscapularis (in 10(-3)mm(2)s(-1), 3.24±0.86 vs. rest 1.37±0.58, pmuscles and deltoid bundles respectively. After a Jobe test, increase in fD* was scattered within the rotator cuff muscles, but was selective for the lateral deltoid compared to the other deltoid bundles (anterior, pmuscle testing of the shoulder muscles with IVIM. This technique has the potential to non-invasively characterize perfusion-related musculoskeletal physiological as well as pathological processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Thyroid perfusion imaging as a diagnostic tool in Graves' disease. Arterial spin labeling magnetic resonance imaging vs. colour-coded Doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Muessig, K. [University Hospital of Duesseldorf (Germany). Dept. of Metabolic Diseases; Leibniz Center for Diabetes Research, Duesseldorf (Germany). Inst. for Clinical Diabetology; University Hospital of Tuebingen (Germany). Div. of Endocrinology, Diabetes, Nephrology, Angiology, and Clinical Chemistry; Schraml, C.; Schwenzer, N.F. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Section on Experimental Radiology; University Hospital of Tuebingen (Germany). Dept. of Radiology, Diagnostic and Interventional Radiology; Rietig, R.; Balletshofer, B. [University Hospital of Tuebingen (Germany). Div. of Endocrinology, Diabetes, Nephrology, Angiology, and Clinical Chemistry; Martirosian, P.; Haering, H.U.; Schick, F. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Section on Experimental Radiology; Claussen, C.D. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Diagnostic and Interventional Radiology

    2012-12-15

    Purpose: Though increased thyroid perfusion assessed by colour-coded Doppler ultrasound (CDUS) is characteristic of Graves' disease (GD), sometimes perfusion assessment by CDUS is not possible. In these cases, arterial spin labelling (ASL), a novel magnetic resonance imaging (MRI) technique allowing non-invasive thyroid perfusion quantification, may have additional diagnostic value. We aimed to evaluate the potential of ASL-MRI for assessment of increased blood perfusion in patients with GD compared to CDUS. Materials and Methods: Thyroid perfusion was measured by CDUS (volume flow rate calculated from pulsed wave Doppler signals and vessel diameter) and ASL-MRI at 1.5 T in 7 patients with GD and 10 healthy controls. Results: In patients with GD, average perfusion in both thyroid lobes was markedly increased compared to controls. Both techniques applied for volume related perfusion as well as absolute volume flow in thyroid feeding vessels provided similar results (all p = 0.0008). Using a cut-off value of 22 ml/min for the volume flow rate assessed by CDUS in the four feeding vessels allowed discrimination between patients with GD and controls in all cases. After adjusting thyroid perfusion for the differences in organ volume, both CDUS and ASL revealed also complete discrimination between health and disease. Conclusion: Thyroid perfusion measurement by ASL-MRI reliably discriminate GD from normal thyroid glands. In patients in whom thyroid arteries cannot be depicted by CDUS for technical or anatomical reasons, ASL-MRI may have additional diagnostic value. (orig.)

  2. Prediction of bone loss in elderly female subjects by MR perfusion imaging and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, James F.; Yeung, David K.W. [Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Shatin, New Territories (China); Leung, Jason Chi Shun; Leung, Ping C. [Chinese University of Hong Kong, Jockey Club Centre for Osteoporosis Care and Control, Prince of Wales Hospital, Shatin (China); Kwok, Timothy C.Y. [Chinese University of Hong Kong, Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin (China)

    2011-06-15

    To determine whether MR perfusion indices or marrow fat content at baseline can predict areal bone mineral density (BMDa) loss. Repeat dual x-ray absorptiometry (DXA) of the hip was performed in female subjects at 2 years (n = 52) and 4 years (n = 45) following baseline MR perfusion imaging and spectroscopy of the hip. Percentage reduction in femoral neck BMDa at 4 years post-baseline was greater in subjects with below median acetabulum enhancement slope (E{sup slope}) (-5.6 {+-} 1.2 Vs -1.1 {+-} 1.2 (mean {+-} standard error) p = 0.014) or muscle maximum enhancement (E{sup max}) (-5.7 {+-} 1.2 Vs -0.23 {+-} 1.2, p = 0.009) after adjusting for baseline co-variables. Baseline MR parameters correlated with reduction in BMDa at 4 years (acetabulum E{sup slope} r = 0.517, p = 0.0003; muscle E{sup max} r = 0.306, p = 0.043) as well as traditionally applied clinical risk factors. Acetabulum E{sup slope}, femoral neck E{sup max} and marrow fat content at baseline had sensitivities of 89%, 81% and 72% respectively at distinguishing between fast (>1%/annum) (n = 18) and slow (<1%/annum) (n = 27) BMD losers. Elderly female subjects with reduced perfusion indices at baseline had increased femoral neck bone loss at 4 years. Selected perfusion indices and marrow fat content have a moderate to high sensitivity in discriminating between fast and slow bone losers. (orig.)

  3. Basic T1 Perfusion magnetic resonance imaging evaluation of the therapeutic effect of neoadjuvant chemotherapy in locally advanced cervical cancer.

    Science.gov (United States)

    Fu, Chun; Feng, Xiaoyan; Bian, Dujun; Du, Wanping; Wang, Xiangquan; Zhao, Yan

    2013-09-01

    The objective of this study was to evaluate the dynamic changes of blood perfusion coinciding with tumor regression after neoadjuvant chemotherapy (NACT) in locally advanced cervical cancer (LACC). Thirty patients with LACC received conventional 3.0-T magnetic resonance imaging and perfusion-weighted imaging scans at 3 different times (before NACT, 2 weeks after the first NACT, and 2 weeks after the second NACT). Characteristics of time-intensity diagrams and patterns of blood perfusion maps according to the parameter of area under the curve (AUC) were observed. Eight perfusion parameters were compared among 3 time points at 2 different chemotherapy-sensitive groups by the software of Basic T1 Perfusion. The effective chemotherapy rate was 73.3% (22/30). The characteristic of time-intensity diagrams in cervical cancer was a rapid onset with plateau. There were 3 patterns of AUC perfusion maps. The common perfusion map was rich blood supply type in the effective chemotherapy group and peripheral blood supply type in the ineffective chemotherapy group. Four parameter values (relative enhancement, maximum enhancement, wash-in rate, and AUC) were significantly reduced 2 weeks after the second NACT than those before the therapy (P = 0.000; P = 0.009; P = 0.011; and P = 0.000) in the effective chemotherapy group, especially the value of relative enhancement 2 weeks after the first NACT, was obviously decreased compared to that before the therapy (P = 0.042). The value of time to peak 2 weeks after the second NACT was significantly longer than that before the therapy in the effective chemotherapy group (P = 0.001). There were no obvious changes of blood perfusion parameters among the 3 different times in the ineffective chemotherapy group. Tumor blood perfusion has obviously decreased after effective NACT in the treatment of LACC.

  4. Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Performed in Acute Perinatal Stroke Reveals Hyperperfusion Associated With Ischemic Injury.

    Science.gov (United States)

    Watson, Christopher G; Dehaes, Mathieu; Gagoski, Borjan A; Grant, P Ellen; Rivkin, Michael J

    2016-06-01

    Perfusion-weighted imaging in adults with acute stroke often reveals hypoperfusion in the ischemic core and in a surrounding area of nondiffusion-restricted penumbral tissue. Perinatal stroke is common, but the perfusion pattern is rarely documented. We aimed to describe the perfusion pattern in newborns with perinatal stroke. Neonates with clinical features of acute stroke underwent magnetic resonance imaging. Perfusion data were obtained using pseudocontinuous arterial spin labeling. Strokes were classified as arterial, venous, or both. Core infarction was determined by the presence of restricted diffusion on diffusion-weighted imaging. Perfusion-weighted imaging and susceptibility-weighted imaging signal in the ischemic area were visually compared with the homologous region in the contralesional hemisphere. Electroencephalogram data were evaluated for seizure activity. In 25 neonates with acute stroke, 8 of 11 (73%) with arterial ischemic stroke demonstrated hyperperfusion, 1 of 9 (11%) with venous stroke, and 4 of 5 (80%) with both. Hypoperfusion was observed in 3 of 9 (33%) with venous and none with arterial ischemic stroke. Perfusion was normal in 4 of 9 (45%) with venous and 1 of 5 (20%) with both. Twenty-one of 24 patients (88%) with electroencephalogram data had either electrographic seizures or focal sharp waves in the ipsilesional hemisphere (11/11 arterial ischemic stroke, 6/9 venous, and 4/5 both). Perfusion-weighted imaging can be obtained in neonates with acute stroke and often reveals hyperperfusion in the infarct core. Penumbra in arterial ischemic stroke is seldom found. Hyperperfusion may be caused by poststroke reperfusion or to neuronal hyperexcitability of stroke-associated seizure. Its identification may be useful for consideration of therapy for acute neonatal stroke. © 2016 American Heart Association, Inc.

  5. Assessment of cardiac function using myocardial perfusion imaging technique on SPECT with 99mTc sestamibi

    Science.gov (United States)

    Gani, M. R. A.; Nazir, F.; Pawiro, S. A.; Soejoko, D. S.

    2016-03-01

    Suspicion on coronary heart disease can be confirmed by observing the function of left ventricle cardiac muscle with Myocardial Perfusion Imaging techniques. The function perfusion itself is indicated by the uptake of radiopharmaceutical tracer. The 31 patients were studied undergoing the MPI examination on Gatot Soebroto Hospital using 99mTc-sestamibi radiopharmaceutical with stress and rest conditions. Stress was stimulated by physical exercise or pharmacological agent. After two hours, the patient did rest condition on the same day. The difference of uptake percentage between stress and rest conditions will be used to determine the malfunction of perfusion due to ischemic or infarct. Degradation of cardiac function was determined based on the image-based assessment of five segments of left ventricle cardiac. As a result, 8 (25.8%) patients had normal myocardial perfusion and 11 (35.5%) patients suspected for having partial ischemia. Total ischemia occurred to 8 (25.8%) patients with reversible and irreversible ischemia and the remaining 4 (12.9%) patients for partial infarct with characteristic the percentage of perfusion ≤50%. It is concluded that MPI technique of image-based assessment on uptake percentage difference between stress and rest conditions can be employed to predict abnormal perfusion as complementary information to diagnose the cardiac function.

  6. Quantitative color analysis for capillaroscopy image segmentation.

    Science.gov (United States)

    Goffredo, Michela; Schmid, Maurizio; Conforto, Silvia; Amorosi, Beatrice; D'Alessio, Tommaso; Palma, Claudio

    2012-06-01

    This communication introduces a novel approach for quantitatively evaluating the role of color space decomposition in digital nailfold capillaroscopy analysis. It is clinically recognized that any alterations of the capillary pattern, at the periungual skin region, are directly related to dermatologic and rheumatic diseases. The proposed algorithm for the segmentation of digital capillaroscopy images is optimized with respect to the choice of the color space and the contrast variation. Since the color space is a critical factor for segmenting low-contrast images, an exhaustive comparison between different color channels is conducted and a novel color channel combination is presented. Results from images of 15 healthy subjects are compared with annotated data, i.e. selected images approved by clinicians. By comparison, a set of figures of merit, which highlights the algorithm capability to correctly segment capillaries, their shape and their number, is extracted. Experimental tests depict that the optimized procedure for capillaries segmentation, based on a novel color channel combination, presents values of average accuracy higher than 0.8, and extracts capillaries whose shape and granularity are acceptable. The obtained results are particularly encouraging for future developments on the classification of capillary patterns with respect to dermatologic and rheumatic diseases.